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Home My WebLink About20101 67th Ave NE_PWD1738_2025 ORMA F ERRA T DESIGN GROUP, INC. C1.2 Unofficial Document Unofficial Document Unofficial Document Unofficial Document Unofficial Document Unofficial Document Unofficial Document Unofficial Document Unofficial Document When Recorded Return to: Chris Gayte, Managing Member PO Box 1727 Bellevue, WA 98009 ACCESS & UTILITY EASEMENT Grantor: GAYTEWAY BUSINESS PARK, LLC, a Washington limited liability company Grantee: GAYTEWAY BUSINESS PARK, LLC, a Washington limited liability company Reference: A.F. No. 201907225010 Legal Description: Ptn of NW1/4 NW1/4, SW1/4 NW1/4, SE1/4 NW1/4 SW1/4 Sec 14 T.31N., R.5E.,W.M. Add'l on ____ Tax Parcels: Ptn 31051400200700 1 â€“ ACCESS & UTILITY EASEMENT THIS ACCESS & UTILITY EASEMENT is made this ___ day of _________, 2020, by Gayteway Business Park, LLC, a Washington Limited Liability Company, Declarant, for the benefit of Declarant and the future owners of the land legally described in Exhibit A and Exhibit B. WHEREAS, Gayteway Business Park LLC a Washington limited liability company is the owner of the Property described in EXHIBIT A (hereafter â€œLOT 1â€ and â€œLOT 3â€) WHEREAS, Gayteway Business Park LLC a Washington limited liability company is the owner of the Property described in EXHIBIT B (hereafter â€œLOT 2â€). Grant, Covenant and Declaration LOT 2 hereby declares, grants and conveys to LOT 1 and LOT 3, an easement in and covenants to keep that area shown in EXHIBIT C and more particularly described in EXHIBIT D and EXHIBIT E as an easement and area for the purposes described below (â€œEasementâ€). Purposes: The purpose of this Easement is for access, ingress, egress, and utilities, burdening that area described in EXHIBIT D, and only for ingress and egress burdening the area described in EXHIBIT E, for the benefit of the Property described in Exhibit A and Exhibit B. General provisions: The doctrine of merger shall not apply to this declaration, easement and covenants herein, and any subsequent conveyance shall take subject to the easement and rights and obligations herein. This easement and the rights and obligations under this easement are intended to and shall run with the Property and shall benefit and bind the Parties and their respective, heirs, successors, and assigns. Executed this __________ day of _____________________, 2020. GRANTOR/DECLARANT: GAYTEWAY BUSINESS PARK, LLC BY: ________________________________ Chris Gayte ITS: Manager_______________________ 2 â€“ ACCESS & UTILITY EASEMENT GRANTEE/DECLARANT: GAYTEWAY BUSINESS PARK, LLC BY: ________________________________ Chris Gayte ITS: Manager_______________________ STATE OF WASHINGTON ) ) ss. COUNTY OF ____________) I certify that I know or have satisfactory evidence that CHRIS GAYTE is the person who appeared before me, and said person acknowledged that he/she signed this instrument, on oath stated that he/she was authorized to execute the instrument and acknowledged it as the MANAGER of GAYTEWAY BUSINESS PARK, LLC, to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. DATED this ___________ day of __________________, 2020. ____________________________________ Signature of Notary Public ____________________________________ My appt. expires: _____________________ 3 â€“ ACCESS & UTILITY EASEMENT EXHIBIT A LOT 1 and LOT 3 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. EXHIBIT B LOT 2 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. 4 â€“ ACCESS & UTILITY EASEMENT 5 â€“ ACCESS & UTILITY EASEMENT EXHIBIT D 6 â€“ ACCESS & UTILITY EASEMENT EXHIBIT E 7 â€“ ACCESS & UTILITY EASEMENT When Recorded Return to: Chris Gayte, Managing Member PO Box 1727 Bellevue, WA 98009 NO BUILD EASEMENT Grantor: GAYTEWAY BUSINESS PARK, LLC, a Washington limited liability company Grantee: GAYTEWAY BUSINESS PARK, LLC, a Washington limited liability company Reference: A.F. No. 201907225010 Legal Description: Ptn of NW1/4 NW1/4, SW1/4 NW1/4, SE1/4 NW1/4 SW1/4 Sec 14 T.31N., R.5E.,W.M. Add'l on ____ Tax Parcels: Ptn 31051400200700 1 â€“ NO BUILD EASEMENT THIS ACCESS & UTILITY EASEMENT is made this ___ day of _________, 2020, by Gayteway Business Park, LLC, a Washington Limited Liability Company for the benefit of the future owners of the land legally described in Exhibit A and Exhibit B. WHEREAS, Gayteway Business Park LLC a Washington limited liability company is the owner of the Property described in EXHIBIT A (hereafter â€œLOT 1â€) WHEREAS, Gayteway Business Park LLC a Washington limited liability company is the owner of the Property described in EXHIBIT B (hereafter â€œLOT 2â€). Grant, Covenant and Declaration LOT 2 hereby declares grants and conveys to LOT 1 an easement in and covenants to keep that area shown in EXHIBIT C and more particularly described in EXHIBIT D an easement and area for the purposes described below (â€œEasementâ€). Purposes: The purpose of this Easement is a no build area such that LOT 1 will not construct any buildings in the area to benefit LOT 2. General provisions: The doctrine of merger shall not apply to this declaration easement and covenants herein, and any subsequent conveyance shall take subject to the easement and rights and obligations herein. This easement and the rights and obligations under this easement are intended to and shall run with the Property and shall benefit and bind the Parties and their respective, heirs, successors, and assigns. Executed this __________ day of _____________________, 2020. GRANTOR/DECLARANT: GAYTEWAY BUSINESS PARK, LLC BY: ________________________________ Chris Gayte ITS: Manager_______________________ 2 â€“ NO BUILD EASEMENT GRANTEE/DECLARANT: GAYTEWAY BUSINESS PARK, LLC BY: ________________________________ Chris Gayte ITS: _Manager_______________________ STATE OF WASHINGTON ) ) ss. COUNTY OF ____________) I certify that I know or have satisfactory evidence that CHRIS GAYTE is the person who appeared before me, and said person acknowledged that he/she signed this instrument, on oath stated that he/she was authorized to execute the instrument and acknowledged it as the MANAGER of GAYTEWAY BUSINESS PARK, LLC, to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. DATED this ___________ day of __________________, 2020. ____________________________________ Signature of Notary Public ____________________________________ My appt. expires: _____________________ 3 â€“ NO BUILD EASEMENT EXHIBIT A LOT 1 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. EXHIBIT B LOT 2 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. 4 â€“ NO BUILD EASEMENT 5 â€“ NO BUILD EASEMENT EXHIBIT D 6 â€“ NO BUILD EASEMENT When Recorded Return to: Chris Gayte, Managing Member PO Box 1727 Bellevue, WA 98009 STORM SYSTEM EASEMENT & MAINTENANCE AGREEMENT Grantor: GAYTEWAY BUSINESS PARK, LLC, a Washington limited liability company Grantee: GAYTEWAY BUSINESS PARK, LLC, a Washington limited liability company Reference: A.F. No. 201907225010 Legal Description: Ptn of NW1/4 NW1/4, SW1/4 NW1/4, SE1/4 NW1/4 SW1/4 Sec 14 T.31N., R.5E.,W.M. Add'l on ____ Tax Parcels: Ptn 31051400200700 1 â€“ STORM SYSTEM AND MAINTENANCE EASEMENT THIS STORM SYSTEM EASEMENT AND MAINTENANCE AGREEMENT is made this ___ day of _________, 2020, by Gayteway Business Park, LLC, a Washington Limited Liability Company for the benefit of the future owners of the land legally described in Exhibit A and Exhibit B. WHEREAS, Gayteway Business Park LLC a Washington limited liability company is the owner of the Property described in EXHIBIT A (hereafter â€œLOT 1â€) WHEREAS, Gayteway Business Park LLC a Washington limited liability company is the owner of the Property described in EXHIBIT B (hereafter â€œLOT 2â€). Grant, Covenant and Declaration LOT 1 hereby declares, grants and conveys to LOT 2 an easement for a storm system as shown on Sheet C1.5 Storm Plan of Gayteway Business Park Building C construction drawings dated 4/8/19 as approved 5/21/19 by the City of Arlington, on file with the City, and/or as actually constructed. LOT 2 hereby declares, grants and conveys to LOT 1 an easement for a storm system, comparable to the system described above, and adequate for purposes of drainage of reasonable commercial development. Purposes: The purpose of these easements and covenants are for the mutual installation, maintenance, repair, and replacement of a Storm System for the benefit of the Property described in Exhibit A and Exhibit B. The properties shall share equitably in the costs and expenses of maintenance and repairs to the systems whether on LOT 1 or LOT 2. General provisions: The doctrine of merger shall not apply to this easement and covenants herein, and any subsequent conveyance shall take subject to the easement and rights. This easement and the rights and obligations under this easement are intended to and shall run with the Property and shall benefit and bind the Parties and their respective, heirs, successors, and assigns. 2 â€“ STORM SYSTEM AND MAINTENANCE EASEMENT Executed this __________ day of _____________________, 2020. GRANTOR/DECLARANT: GAYTEWAY BUSINESS PARK, LLC BY: ________________________________ Chris Gayte ITS: Manager_______________________ GRANTEE/DECLARANT: GAYTEWAY BUSINESS PARK, LLC BY: ________________________________ Chris Gayte ITS: _Manager_______________________ STATE OF WASHINGTON ) ) ss. COUNTY OF ____________) I certify that I know or have satisfactory evidence that CHRIS GAYTE is the person who appeared before me, and said person acknowledged that he/she signed this instrument, on oath stated that he/she was authorized to execute the instrument and acknowledged it as the MANAGER of GAYTEWAY BUSINESS PARK, LLC, to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. DATED this ___________ day of __________________, 2020. ____________________________________ Signature of Notary Public ____________________________________ My appt. expires: _____________________ 3 â€“ STORM SYSTEM AND MAINTENANCE EASEMENT EXHIBIT A LOT 1 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. EXHIBIT B LOT 2 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. 4 â€“ STORM SYSTEM AND MAINTENANCE EASEMENT AFTER RECORDING, RETURN TO: CITY OF ARLINGTON 18204 59th Avenue NE Arlington, WA 98223 UTILITY EASEMENT GRANTOR (S): Gayteway Business Park LLC, a Washington limited liability company GRANTEE (S): City of Arlington, Washington LEGAL (Abbrev.): Ptn of NW1/4 NW1/4, SW1/4 NW1/4, SE1/4 NW1/4 SW1/4 Sec 14 T.31N., R.5E.,W.M. ASSESSORâ€™S TAX #: 31051400200700 THIS AGREEMENT is made and entered into this _______ day of ___________, 2020 by and between Gayteway Business Park LLC, (hereinafter â€œGrantorsâ€) and the City of Arlington, Washington (hereinafter â€œCityâ€); and WASHINGTON TRUST BANK and COMMERCIAL GRADE, LLC (hereinafter referred to as â€œMortgageesâ€). WHEREAS, Grantors are the owners of certain property located within the City of Arlington, Washington; and WHEREAS, Grantor wishes to grant an easement to the Grantee; NOW, THEREFORE, for valuable consideration, the receipt of which is hereby acknowledged, it is agreed by and between the parties hereto as follows: CITY OF ARLINGTON UTILITY EASEMENT 1. Grant of Easements by Grantors to the City. 1.1 Grantors convey and grant to the City of Arlington, its successors and assigns and permittees and licensees, a perpetual easement for utilities and the right, privilege and authority to construct, alter, improve, repair, operate and maintain a storm sewer, sanitary sewer lines, and/or water lines, pipes, and appurtenances, over, under and across Grantorâ€™s property legally described as follows: Attached Exhibit â€œAâ€ â€“ Lot 2. And the easement area is limited to that area legally described in Exhibit B, and shown on Exhibit C where water lines and sewer lines are actually constructed, together with the right to ingress to and egress from said lands across adjacent lands of the Grantor, for the purpose of constructing, reconstructing, repairing, renewing, altering, changing, patrolling, and operating the said lines and appurtenances, and the right at any time to remove said lines and appurtenances from said lands. 1.2 The Grantor reserves the right to use the surface of the above- described easement area in any manner now existing, but shall not erect any buildings, structures, patios, or other construction of any nature on said easement area; provided, however, that Grantor shall have the right to make any use of the easement area not inconsistent with the Granteeâ€™s rights hereunder. 2. General Terms. 2.1 Entire Agreement. This Agreement contains all of the agreements of the parties and no prior agreements or understandings pertaining to any such matters shall be effective for any such purpose. 2.2 Modification. No provision of this Agreement may be amended or added to except by agreement in writing signed by the parties. 2.3 Successors in interest. This easement shall be a covenant running with the land and shall be binding on the Grantor, and Grantorâ€™s heirs, successors and assigns forever. 2.4 Subordination of Mortgage. Any mortgage on said land held by Mortgagees shall be subordinated to the rights herein granted to the Grantee, but in all other respects shall remain unimpaired. CITY OF ARLINGTON UTILITY EASEMENT DATED this ______ day of ____________, 2020. GRANTOR: Gayteway Business Park LLC By: ________________________ This record was acknowledged before me on by (date) CHRIS GAYTE as MANAGER of GAYTEWAY BUSINESS PARK, LLC (name) (type of authority) (name of party/company) __________________________________________________ Notary Public for the State of Washington My Commission Expires: ______ CITY OF ARLINGTON UTILITY EASEMENT MORTGAGEE: WASHINGTON TRUST BANK By: ________________________ This record was acknowledged before me on by (date) as of _____ (name) (type of authority) (name of party/company) __________________________________________________ Notary Public for the State of Washington My Commission Expires: ______ MORTGAGEE: COMMERCIAL GRADE, LLC By: ________________________ This record was acknowledged before me on by (date) as of _____ (name) (type of authority) (name of party/company) __________________________________________________ Notary Public for the State of Washington My Commission Expires: ______ CITY OF ARLINGTON UTILITY EASEMENT EXHIBIT A LOT 2 of Boundary Line Adjustment for Gayteway Business Park recorded under Auditorâ€™s File Number 201907225010, Snohomish County Records. Situate in Snohomish County, Washington. CITY OF ARLINGTON UTILITY EASEMENT EXHIBIT B CITY OF ARLINGTON UTILITY EASEMENT EXHIBIT B- continued CITY OF ARLINGTON UTILITY EASEMENT CITY OF ARLINGTON UTILITY EASEMENT 67TH AVENUE NE (COLLECTOR ARTERIAL) S S S S 0.66 0.60 0.58 0.56 0.54 0.53 0.53 0.53 0.53 0.52 0.53 0.55 0.58 0.62 0.69 0.77 0.85 0.93 0.99 1.03 1.03 1.01 1.01 1.01 1.01 1.02 1.01 1.00 0.96 0.89 0.81 0.72 0.65 0.58 0.55 0.52 0.50 0.50 0.51 0.51 0.51 0.50 0.51 0.52 0.53 0.56 0.60 0.68 0.79 0.89 0.99 1.08 1.14 1.15 1.13 1.14 1.12 1.12 1.14 1.16 1.13 1.06 0.97 0.87 0.77 0.67 0.61 0.57 0.56 0.54 0.53 0.53 0.53 0.53 0.53 0.54 0.55 0.56 0.58 0.63 0.71 0.82 0.92 1.01 1.10 1.15 1.16 1.13 1.14 1.14 1.12 1.15 1.15 1.12 1.04 0.95 0.86 0.75 0.66 0.59 0.57 0.55 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.54 0.56 0.58 0.63 0.72 0.83 0.93 1.02 1.10 1.15 1.16 1.13 1.14 1.14 1.13 1.15 1.16 1.11 1.04 0.94 0.85 0.74 0.65 0.59 0.57 0.55 0.54 0.53 0.54 0.54 0.54 0.53 0.54 0.55 0.57 0.59 0.64 0.73 0.84 0.93 1.03 1.11 1.16 1.16 1.13 1.14 1.14 1.12 1.14 1.14 1.10 1.02 0.92 0.83 0.72 0.63 0.57 0.55 0.52 0.51 0.51 0.51 0.51 0.51 0.50 0.50 0.51 0.53 0.56 0.61 0.68 0.77 0.85 0.92 0.72 0.66 0.63 0.62 0.60 0.59 0.58 0.58 0.58 0.58 0.59 0.61 0.63 0.66 0.74 0.84 0.94 1.03 1.12 1.18 1.20 1.17 1.17 1.18 1.17 1.17 1.18 1.15 1.08 0.98 0.89 0.78 0.69 0.62 0.59 0.57 0.56 0.55 0.55 0.56 0.56 0.56 0.57 0.58 0.59 0.61 0.66 0.74 0.85 0.97 1.07 1.16 1.25 1.29 1.27 1.27 1.25 1.25 1.28 1.29 1.23 1.14 1.04 0.94 0.83 0.72 0.66 0.63 0.61 0.60 0.59 0.58 0.58 0.58 0.59 0.60 0.61 0.62 0.64 0.69 0.77 0.89 1.00 1.09 1.19 1.26 1.30 1.27 1.27 1.28 1.25 1.29 1.28 1.22 1.12 1.03 0.92 0.81 0.71 0.65 0.62 0.61 0.59 0.58 0.58 0.58 0.58 0.58 0.59 0.60 0.62 0.64 0.69 0.78 0.90 1.00 1.10 1.20 1.27 1.29 1.26 1.27 1.28 1.26 1.29 1.28 1.21 1.12 1.02 0.92 0.80 0.70 0.65 0.62 0.61 0.60 0.59 0.58 0.58 0.58 0.59 0.60 0.61 0.62 0.65 0.70 0.79 0.91 1.01 1.11 1.20 1.27 1.29 1.26 1.25 1.27 1.26 1.29 1.26 1.20 1.10 1.00 0.89 0.78 0.68 0.63 0.60 0.59 0.57 0.56 0.56 0.56 0.56 0.55 0.56 0.57 0.58 0.60 0.65 0.74 0.84 0.94 1.03 0.79 0.73 0.68 0.66 0.64 0.63 0.63 0.62 0.62 0.63 0.64 0.66 0.68 0.72 0.79 0.90 1.02 1.11 1.20 1.28 1.32 1.30 1.30 1.30 1.30 1.30 1.30 1.24 1.15 1.06 0.96 0.84 0.74 0.67 0.64 0.62 0.61 0.60 0.60 0.60 0.60 0.60 0.61 0.62 0.64 0.67 0.73 0.81 0.92 1.05 1.16 1.25 1.32 1.37 1.37 1.37 1.36 1.36 1.37 1.36 1.31 1.22 1.13 1.02 0.89 0.79 0.72 0.68 0.65 0.63 0.63 0.62 0.62 0.62 0.62 0.63 0.64 0.66 0.70 0.75 0.84 0.95 1.08 1.18 1.27 1.34 1.38 1.37 1.38 1.39 1.36 1.37 1.35 1.30 1.21 1.12 0.99 0.87 0.77 0.71 0.67 0.64 0.63 0.62 0.62 0.62 0.62 0.62 0.63 0.64 0.66 0.70 0.76 0.84 0.96 1.09 1.19 1.28 1.34 1.38 1.37 1.38 1.38 1.37 1.38 1.35 1.29 1.20 1.11 0.98 0.86 0.77 0.71 0.67 0.64 0.63 0.62 0.62 0.62 0.62 0.62 0.63 0.64 0.67 0.71 0.77 0.86 0.98 1.10 1.20 1.29 1.35 1.38 1.37 1.35 1.38 1.36 1.37 1.34 1.28 1.18 1.09 0.96 0.84 0.75 0.69 0.65 0.63 0.62 0.61 0.60 0.60 0.60 0.60 0.61 0.62 0.63 0.66 0.71 0.79 0.91 1.02 1.11 0.84 0.76 0.71 0.67 0.65 0.64 0.65 0.65 0.65 0.65 0.66 0.68 0.749+00 2 0.78 0.85 0.96 1.09 1.20 1.29 1.36 1.41 1.41 1.38 1.42 1.41 1.50+00 39 1.38 1.32 1.24 1.15 1.03 0.90 0.80 0.73 0.68 0.65 0.63 0.63 0.62 0.63 0.63 0.62 0.62 0.64 0.66 0.71 0.77 0.85 0.96 1.08 1.2251+00 1.32 1.41 1.47 1.50 1.50 1.51 1.51 1.50 1.46 1.39 1.30 1.19 1.052+005 0.93 0.83 0.76 0.70 0.66 0.64 0.63 0.63 0.64 0.64 0.63 0.63 0.65 0.68 0.73 0.79 0.88 0.98 1.11 1.24 1.35 1.43 1.48 1.51 1.50 153+00 .54 1.51 1.49 1.45 1.38 1.28 1.16 1.03 0.91 0.82 0.75 0.69 0.66 0.64 0.63 0.63 0.64 0.64 0.63 0.63 0.65 0.68 0.73 0.80 0.89 1.054+00 0 1.13 1.26 1.35 1.43 1.49 1.51 1.50 1.50 1.51 1.49 1.44 1.37 1.55+00 27 1.15 1.02 0.90 0.81 0.74 0.69 0.65 0.63 0.63 0.63 0.64 0.63 0.63 0.63 0.65 0.69 0.74 0.81 0.90 1.01 1.14 1.26 1.36 1.44 1.4956+00 1.51 1.50 1.50 1.50 1.48 1.43 1.35 1.26 1.13 1.00 0.88 0.80 0.757+00 3 0.68 0.65 0.63 0.63 0.63 0.63 0.63 0.63 0.63 0.64 0.67 0.71 0.77 0.86 0.97 1.10 1.2058+00 0.84 0.76 0.70 0.66 0.63 0.63 0.63 0.63 0.63 0.63 0.65 0.68 0.73 0.80 0.88 0.99 1.11 1.24 1.35 1.43 1.49 1.52 1.53 1.56 1.52 1.51 1.46 1.39 1.30 1.18 1.05 0.93 0.83 0.75 0.69 0.65 0.62 0.62 0.62 0.62 0.62 0.61 0.61 0.63 0.66 0.71 0.78 0.87 0.97 1.09 1.21 1.33 1.43 1.51 1.56 1.59 1.60 1.58 1.55 1.49 1.41 1.30 1.17 1.05 0.94 0.84 0.76 0.70 0.65 0.62 0.61 0.61 0.61 0.61 0.61 0.61 0.63 0.67 0.72 0.80 0.89 0.99 1.11 1.23 1.36 1.45 1.52 1.57 1.60 1.59 1.58 1.54 1.48 1.39 1.28 1.15 1.03 0.92 0.83 0.75 0.69 0.64 0.62 0.61 0.61 0.61 0.61 0.61 0.61 0.63 0.67 0.73 0.81 0.90 1.00 1.12 1.25 1.37 1.46 1.53 1.57 1.60 1.59 1.58 1.53 1.47 1.38 1.26 1.14 1.02 0.91 0.82 0.74 0.68 0.64 0.61 0.60 0.61 0.61 0.61 0.60 0.61 0.63 0.68 0.73 0.81 0.91 1.01 1.13 1.26 1.38 1.47 1.53 1.57 1.59 1.59 1.57 1.53 1.46 1.37 1.25 1.12 1.01 0.90 0.81 0.73 0.68 0.64 0.62 0.61 0.62 0.62 0.62 0.62 0.62 0.64 0.68 0.73 0.80 0.89 1.00 1.13 1.26 0.81 0.73 0.67 0.63 0.60 0.58 0.58 0.58 0.58 0.59 0.61 0.66 0.71 0.79 0.88 0.99 1.10 1.23 1.35 1.45 1.53 1.58 1.62 1.62 1.60 1.55 1.49 1.40 1.29 1.16 1.04 0.93 0.83 0.74 0.68 0.63 0.59 0.58 0.58 0.58 0.58 0.57 0.58 0.60 0.64 0.69 0.76 0.84 0.95 1.07 1.20 1.34 1.45 1.55 1.63 1.69 1.71 1.66 1.60 1.52 1.42 1.29 1.16 1.03 0.91 0.81 0.73 0.66 0.61 0.58 0.56 0.55 0.55 0.55 0.55 0.57 0.60 0.64 0.69 0.77 0.86 0.97 1.09 1.22 1.36 1.47 1.57 1.64 1.70 1.71 1.65 1.59 1.50 1.40 1.27 1.14 1.01 0.90 0.80 0.72 0.66 0.61 0.58 0.56 0.56 0.56 0.56 0.56 0.57 0.60 0.64 0.70 0.78 0.87 0.98 1.11 1.24 1.37 1.48 1.58 1.64 1.70 1.71 1.65 1.59 1.49 1.39 1.25 1.12 1.00 0.88 0.78 0.71 0.65 0.60 0.57 0.55 0.55 0.55 0.55 0.55 0.57 0.60 0.64 0.70 0.78 0.88 0.99 1.12 1.25 1.38 1.49 1.58 1.65 1.71 1.70 1.64 1.58 1.48 1.38 1.24 1.11 0.99 0.88 0.78 0.71 0.65 0.61 0.58 0.57 0.57 0.58 0.58 0.58 0.59 0.62 0.66 0.72 0.80 0.89 1.00 1.12 1.25 0.75 0.68 0.62 0.58 0.54 0.52 0.51 0.51 0.51 0.53 0.56 0.61 0.67 0.74 0.83 0.94 1.06 1.19 1.33 1.45 1.55 1.63 1.69 1.71 1.66 1.59 1.51 1.40 1.27 1.14 1.01 0.89 0.79 0.70 0.64 0.58 0.55 0.52 0.51 0.51 0.51 0.51 0.53 0.56 0.59 0.64 0.70 0.78 0.87 0.97 1.09 1.21 1.31 1.40 1.50 1.63 1.66 1.58 1.46 1.38 1.28 1.17 1.05 0.94 0.83 0.74 0.67 0.61 0.56 0.52 0.49 0.48 0.48 0.48 0.49 0.51 0.54 0.58 0.64 0.71 0.78 0.88 0.99 1.10 1.22 1.32 1.42 1.51 1.64 1.66 1.56 1.45 1.36 1.27 1.15 1.03 0.92 0.82 0.73 0.66 0.60 0.56 0.52 0.50 0.48 0.48 0.48 0.49 0.51 0.55 0.59 0.65 0.71 0.80 0.89 1.00 1.12 1.24 1.33 1.42 1.52 1.65 1.65 1.54 1.44 1.35 1.25 1.13 1.01 0.90 0.80 0.72 0.65 0.59 0.54 0.51 0.48 0.47 0.47 0.47 0.49 0.51 0.54 0.59 0.65 0.72 0.80 0.90 1.01 1.12 1.24 1.34 1.43 1.54 1.65 1.65 1.53 1.43 1.35 1.25 1.13 1.01 0.90 0.81 0.73 0.66 0.61 0.56 0.53 0.51 0.51 0.51 0.51 0.52 0.54 0.57 0.62 0.68 0.76 0.86 0.97 1.10 1.23 EX. FH 30.0' EX. 12"W EX. 12"W EX. 2" WATER SERV.EX. 2" WATER SERV. EX. 12"W N 01Â°36'55" E EX. 8"GV S N 02Â°00'48" E 1 2 10+00 118.02' 798.89' 370.54' 5 A S P H A L T 67th Illuminance (Fc) Average = 0.92 Maximum = 1.71 Minimum = 0.47 Avg/Min Ratio = 1.96 Luminaire Definition(s) GCM2-40H-MV-WW-2R-XX-850 S GCM2-40H-MV-WW-2R-XX-850 S Grey painted cast aluminum housing with plastic drive Filename GCM2-40H-MV-WW-2R-XX-850 S.ies Lumens Per Lamp N.A. Number of Lamps 40 Total Lamp Lumens N.A. Arrangement Lamp Lumens N.A. Arrangement Luminaire Lumens 11960 Luminaire Lumens 11960 Luminaire Efficiency (%) N.A. Total Light Loss Factor 0.900 Luminaire Watts 107 Arrangement Watts 107 Arrangement SINGLE Arm Length 7.5 Offset 0 Pole Mounted Road Classification Type II, Medium, N.A. (deprecated) Upward Waste Light Ratio 0.00 Luminaire Classification System (LCS) Lumens % Lamp % Luminaire LCS-FL 1211.4 N.A. 10.1 LCS-FM 4796.4 N.A. 40.1 LCS-FH 2898.7 N.A. 24.2 LCS-FVH 66.7 N.A. 0.6 LCS-BL 798.3 N.A. 6.7 LCS-BM 1387.4 N.A. 11.6 LCS-BH 779.2 N.A. 6.5 LCS-BVH 21.9 N.A. 0.2 LCS-UL 0.0 N.A. 0.0 LCS-UH 0.0 N.A. 0.0 Total 11960.0 N.A. 100.0 BUG Rating B2-U0-G2 Indoor Classification Direct LER 112 1 AGi32 - Copyright 1999-2019 by Lighting Analysts, Inc. 12/6/2019 Job File: Gayetway Light Levels.AGI Calculations based on published IES Methods and recommendations, values rounded for display purposes. Results derived from content of manufacturers photometric file. Calculation Summary 67th Curb to curb Project: Project_1 Polygon Coordinates in Feet Point Spacing L-R 5 Point Spacing T-B 5 Grid Orient 0 Grid Tilt 0 Meter Type Horizontal Illuminance (Fc) Average 0.92 Maximum 1.71 Minimum 0.47 Avg/Min 1.96 2 AGi32 - Copyright 1999-2019 by Lighting Analysts, Inc. 12/6/2019 Job File: Gayetway Light Levels.AGI Calculations based on published IES Methods and recommendations, values rounded for display purposes. Results derived from content of manufacturers photometric file. CIRCUIT A 107W @ 240V = 0.54 AMP/LUM TOTAL LOAD = (7 x 0.54) = 3.78 AMPS 67TH AVE NE 1 2 3 4 5 6 7 Service 10â€™ 172â€™ 166â€™ 166â€™ 166â€™ 166â€™ 166â€™ CIRCUIT A Vd=2ALR =2(3.78)(5+10+5=20)R = 151.2R =2(3.24)(5+172+5=182)R = 1179.36R =2(2.7)(5+166+5=176)R = 950.4R =2(2.16)(5+166+5=176)R = 760.32R =2(1.62)(5+166+5=176)R = 570.24R =2(1.08)(5+166+5=176)R = 380.16R =2(0.54)(5+166+10=181)R = 195.48R TOTAL = 4187.16R R=0.000809 FOR #8 = 3.39 VOLTS POLE & BRACKET 2(0.54)(50)(.001290) = .07 VOLTS TOTAL = 3.46 VOLTS 3.46V/240V = 0.0144 = 1.4% < 5% THEREFORE #8 WIRE OK LDH 12.6.19 Gayteway Business Park Sheet 1 Line Loss Calculations a S S O C a t e d earth sciences i n c o 1Â· p o 1Â· a t e d FIELD REPORT Page 1 of 2 911 Fifth Avenue Date Project Name Project No. Kirkland, Washington 98033 9-16-19 I Gayteway Business Park 150563E001 Phone: 425-827-7701 Location Municipality Weather Fax: 425-827-5424 20015 67th Avenue NE I Arlington Cloudy 60's www.aesgeo.com Permit No. DPD No. Report No. 1738 I 38 Engineer/ Architect TO: GS Venture Partners Craft Architects P.O. Box 1727 Client/Owner Bellevue, WA 98009-1727 GS Venture Partners ATTN: Chris Gayte General Contractor/Superintendent USVET / Chris Earthwork /Superintendent AS REQUESTED BY: Contractor USVET / Chris THE FOLLOWING WAS NOTED: AESI was onsite part-time, at the request of the earthwork contractor, to conduct density testing and construction observations for the "Gayteway Business Park" project. Mass Grading (Building Cl Prior to our arrival, the earthwork contractor had continued mass grading processes near the north and central portions of Building C. Using a large excavator, the contractor removed approximately 2' of material (generally brownish gray gravelly SAND with trace silts) from the southern portions of the proposed building pad area and placed the material as fill in a recently over-excavated area to the immediate north. AESI observed the fill was placed in a series of approximately 1' loose lifts and compacted/re-compacted (as recommended) to a firm/unyielding condition (corresponding T-probe depths of 2-3") via large vibratory roller. AESI conducted density testing on the structural fill to confirm the specified minimum compaction for the building pad area (95% ASTM 1557). The contractor was notified of all density results listed below and noted they would continue grading activities in the area tomorrow. See Figure 1. Density Results Test# Location Depth (ft below fsg) % Moist Dry Density (pcf) Proctor (pcf) % Proctor P/F DTl Grading/See Figure 1 -6 9.8 118.5 122.1 97.1 p DT2 Grading/See Figure 1 -6 10.1 120.4 122.1 98.6 p DT3 Grading/See Figure 1 -4 8.2 117.7 122.1 96.4 p DT4 Grading/See Figure 1 -3 9.7 120 122.1 98.3 p DT5 Grading/See Figure 1 -3 7.6 118.2 122.1 96.8 p DT6 Grading/See Figure 1 -6 8.8 116.9 122.1 95.7 p Copies To: Distribution Field Rep: Jon D. Hansen, Sr. Staff Geologist Date Mailed: 9/23/2019 Pr;n,;pal / PM, Matt Mrner, P.E. ï¿½F------ V. 6/14 This document is considered a DRAFT until signed or initialed by an AES/ Principal or P ï¿½ect Manager AESI FIELD REPORT Page2of2 To: Project Name: Gayteway Business Park Date: 9-16-19 Project No.: 150563E001 Permit No. DPD No. Figure 1: Building C Earthwork Activities Copies To: Field Rep: Jon D. Hansen, Sr. Staff Geologist Date Mailed: 9/23/2019 Principal/ PM: Matt Miller, P.E. V.6/14 This document is considered o DRAFT until signed or initialed by on AES/ Principal or Project Manager a S S O C a t e d earth sciences i n c o 1Â· p o i- a t e d FIELD REPORT Page 1 of 2 911 Fifth Avenue Date Project Name Project No. Kirkland, Washington 98033 9-17-19 I Gayteway Business Park 150563E001 Phone: 425-827-7701 Location Municipality Weather Fax: 425-827-5424 20015 67th Avenue NE I Arlington Lt Rain 60's www.aesgeo.com Permit No. DPD No. Report No. 1738 I 39 Engineer/ Architect TO: GS Venture Partners Craft Architects P.O. Box 1727 Client/Owner Bellevue, WA 98009-1727 GS Venture Partners ATTN: Chris Gayte General Contractor/Superintendent USVET / Chris Earthwork /Superintendent AS REQUESTED BY: Contractor USVET / Chris THE FOLLOWING WAS NOTED: AESI was onsite part-time, at the request of the earthwork contractor, to conduct density testing and construction observations for the "Gayteway Business Park" project. Mass Grading (Building C) Prior to our arrival, the earthwork contractor had continued mass grading processes for the northwest portions of Building C. Using a medium-sized dozer, the contractor placed approximately 1-1.5' of 3" minus crushed recycled concrete (from onsite stockpile) and compacted/re-compacted (as recommended) the material via large vibratory roller. Per ASTM methodology for evaluating overÂ sized material; AESI performance evaluated the crushed product, both visually and with a .5" steel T-probe, and observed the material to be firm (corresponding T-probe depths of 1-2.5") and unyielding (under the wheel load of earthwork equipment). Based on the above observations; it is the opinion of AESI that the compacted fill is currently suitable. The contractor informed us they would continue using the recycled material thï¿½oughout the week and that the current grades were approximately 2-4' (S-N) below finish subgrade elevations. See Figure 1. Copies To: Distribution Field Rep: Date Mailed: 9/23/2019 Principal/ PM: Matt Miller, P.E. V. 6/14 This document is considered a DRAFT until signed or initialed by an AES/ Principal or Project Manager AESI FIELD REPORT Page 2 of 2 To: Project Name: Gayteway Business Park Date: 9-17-19 Project No.: 150563E001 Permit No. DPD No. Figure 1: Building C Earthwork Activities Copies To: Field Rep: Jon D. Hansen, Sr. Staff Geologist Date Mailed: 9/23/2019 Principal/ PM: Matt Miller, P.E. V. 6/14 This document is considered a DRAFT until signed or initialed by an AES/ Principal or Project Manager DESIGN GROUP, INC. ORMAF ERRAT C1.4 Gayteway Building B Punch List - Remove cold patch along the east side of 67th in front of the mobile home park - Seeding the area between 67th and the pedestrian path - 67th Street Trees - Pedestrian Trail Removable Bollards - Street Lights shown on the frontage improvement plans - Fire Hydrants shown on the frontage improvement plans - Paved wing at the ADA ramp between the trail and 67th - Remove inlet socks and clean out catch basins (End of Project item) Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 April 1, 2020 Page 1 of 1 Mike Wolanek Arlington City, Water 154 W Cox Avenue Arlington, WA 98223 RE: 20-10869 - Gateway Dear Mike Wolanek, Your project: Gateway, was received on Tuesday March 31, 2020. All samples were analyzed within the accepted holding times and were appropriately preserved and analyzed according to approved analytical protocols, unless noted in the data or QC reports. The quality control data was within laboratory acceptance limits, unless specified in the data or QC reports. If you have questions phone us at 800 755-9295. Respectfully Ceann K Knox Lab Manager, Bellingham Enclosures: Data Report FORM: COVER Rev 2 Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21238 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 1 Sample Type: D - Drinking Water Date Collected: 3/31/20 09:03 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #1 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21239 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 2 Sample Type: D - Drinking Water Date Collected: 3/31/20 09:15 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #1 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21240 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 3 Sample Type: D - Drinking Water Date Collected: 3/31/20 09:42 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #2 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21241 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 4 Sample Type: D - Drinking Water Date Collected: 3/31/20 10:20 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #2 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21242 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 5 Sample Type: D - Drinking Water Date Collected: 3/31/20 10:54 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Blowoff Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21243 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 6 Sample Type: D - Drinking Water Date Collected: 3/31/20 11:06 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Blowoff Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 April 6, 2020 Page 1 of 1 Mike Wolanek Arlington City, Water 154 W Cox Avenue Arlington, WA 98223 RE: 20-11326 - Gateway Dear Mike Wolanek, Your project: Gateway, was received on Friday April 03, 2020. All samples were analyzed within the accepted holding times and were appropriately preserved and analyzed according to approved analytical protocols, unless noted in the data or QC reports. The quality control data was within laboratory acceptance limits, unless specified in the data or QC reports. If you have questions phone us at 800 755-9295. Respectfully Ceann K Knox Lab Manager, Bellingham Enclosures: Data Report FORM: COVER Rev 2 Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-11326 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21979 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 1 Sample Type: D - Drinking Water Date Collected: 4/3/20 08:47 Sample Purpose: Investigative or Other Date Received: 4/3/20 Sample Location: Fire Line Date Set: 4/3/20 12:20 County: Snohomish Date Analyzed: 4/4/20 15:28 Sampled By: Augusto Tararan Report Date: 4/6/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jln SM9223 B m_200403sure 3 E. COLI Absent per 100mL SM9223 B m_200403sure If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-11326 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21980 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 2 Sample Type: D - Drinking Water Date Collected: 4/3/20 08:50 Sample Purpose: Investigative or Other Date Received: 4/3/20 Sample Location: Fire Line Date Set: 4/3/20 12:20 County: Snohomish Date Analyzed: 4/4/20 15:28 Sampled By: Augusto Tararan Report Date: 4/6/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jln SM9223 B m_200403sure 3 E. COLI Absent per 100mL SM9223 B m_200403sure If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/3/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Grading Yes N/A The contractor is grading in preparation of trail paving at the building B access Drainage Yes Yes Drainage structure connections at catch basins 10 and 11 had cracks in the curing grout that were patched. See photos. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photos under the Work Performed section. TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/6/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Grading Yes N/A The contractor is grading in preparation of trail paving at the building B access TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photos under the Work Performed section. TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/7/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Grading Yes Yes The contractor is grading in preparation of trail paving at the building B access. Fill material is per the COA standards. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photo. TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/8/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Pedestrian Ramps (Concrete) Yes Yes The contractor placed concrete for the pedestrian ramps on the north end of the project near the mobile home park. Kevin Olander approved the ramps for concrete. See project files. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photo. TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/9/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Driveway Section (Concrete) Yes Yes The contractor placed concrete for the northern access. Kevin Olander performed the inspection. See the project files for documentation. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photo. See Inspector Comments TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. The spacing of the barrels is a bit erratic on the west row of barrels. The foreman told me that the neighbors across the street have been moving and removing barrels at the end of the day after the crews leave. I found a couple barrels in the field next to the project (See photo above). The foreman told me that they would straighten them out. He also informed me that northwest cone would be out the following day for another concrete pour. He would talk to them about fixing up the detour while they were out. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/10/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Driveway Section (Concrete) Yes Yes The contractor placed concrete for the northern access. I inspected the flatwork. See the photos below. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photo. Closure for concrete pour Yes The traffic control subcontractor set up a temporary detour so that the concrete truck. TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A Page 2 INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. The spacing of the barrels is a bit erratic on the west row of barrels. The traffic control subcontractor told me that they would adjust the spacing. I visited the site later in the day and the barrel spacing was fixed. Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/13/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Trail Paving Yes Yes 3â€ of HMA was placed between the north access and the cut in the existing trail to the south of the access point. Backfill catch basins Yes Yes While the paving crews were placing HMA, the prime contractorâ€™s crew assisting the operation backfilled two open catch basins. The contractor told me that they considered the open pit a safety hazard and filling the hole is considered essential construction. Concrete Finishing Yes N/A Paving crew is scoring the driveway section per the paving plans. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the Contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Temporary trail detour Yes Contractor is maintaining the lane shift/trail detour. See photos. Closure for HMA paving Yes The traffic control subcontractor set up a temporary detour so that the HMA truck can access the work site. Page 2 TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/14/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Trail Cleanup/Traffic Control Yes N/A The contractor has opened up the closed Removal section of trail. The crews removed the existing temp traffic control, cleaned up the site, and fenced off the open area to the north end of the project. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS For health and safety, the contractor is proceeding with the reconstruction of the HMA trail. The remainder of the job site is shut down. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/15/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜ - Yes â˜’ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? N/A TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Per the governorâ€™s COVID-19 order, all nonessential construction is to shut down. The site is currently shut down. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/16/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜ - Yes â˜’ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? N/A TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Per the governorâ€™s COVID-19 order, all nonessential construction is to shut down. The site is currently closed. Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/17/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜ - Yes â˜’ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? N/A TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Per the governorâ€™s COVID-19 order, all nonessential construction is to shut down. The site is currently closed. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/20/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building Work N/A N/A Building work only. Crews are installing windows and doors. No Civil work to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS The contractor considers the work to install windows and doors to be essential construction per the governorâ€™s COVID-19 order and is proceeding with that work. Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/21/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜ - Yes â˜’ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? N/A TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS The contractors considers the work to install windows and doors on the buildings to be essential construction per the governorâ€™s COVID-19 order and is proceeding with the work. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/22/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? N/A TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS The contractor considers the work to install windows and doors to be essential construction per the governorâ€™s COVID-19 order and they are proceeding with that work. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/23/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work N/A N/A Crews are installing windows and doors TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS The contractor considers the installation of windows and doors to be essential construction per the governorâ€™s COVID-19 order and is proceeding with that work. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/24/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜ - Yes â˜’ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? N/A TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Per the governorâ€™s COVID-19 order, all nonessential construction is to shut down. The site is currently closed. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/27/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work N/A N/A All building work. No civil to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS The contractor considers the work to install windows and doors to be essential work per the governorâ€™s COVID-19 order and is moving forward with the work required to get windows and doors in. Page 2 8 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/28/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing a catch basin for the building C infiltration trench (south catch basin) TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Crews have COVID-19 plan and procedures in place per the governorâ€™s proclamation. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/29/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are mudding the connections for the pipes to the infiltration gallery for building C. I inspected the catch basin connections. There is still one pipe that needs to be connected to the catch basin east of the infiltration gallery catch basin. Crews will call for another inspection tomorrow to bury the remaining catch basin. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Per the governorâ€™s COVID-19 order, all nonessential construction is to shut down. The site is currently closed. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 4/30/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews finished setting the risers and caps for the south catch basins of the building C infiltration gallery. I told the foreman that they ca burry the catch basins. The building drainage still needs to be connected to the east catch basin. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/5/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work N/A N/A Building work only. No civil to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/6/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work N/A N/A All building work. No civil to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/7/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work (Water line & N/A N/A Building work only. No civil to report. Interior work) TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/8/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work N/A N/A Building work only. No civil to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/11/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building & Grading work Yes N/A Crews are setting curb in front of Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/12/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Concrete Curb Yes Yes Crews are placing slip form concrete curb on the south side of Building B. Grading Yes N/A Crews are grading in the area between Building B and C.s TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/13/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building & Curb work Yes N/A Crews are setting curb in front of Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/14/2020 Gayteway Business Park Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews finished setting pipe connections for 2 catch basins on the east side of building C. See the photos below. Concrete Curb Yes Yes Crews are forming and installing slip form concrete curb sections for the parking lot of building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the Contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/15/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews set one pipe connection on the east side of Building C. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/18/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building & Curb work Yes N/A Crews are setting curb for Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/19/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Grading Yes N/A Crews are grading in preparation of parking lot paving. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/20/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Grading Yes N/A Crews are grading in preparation of parking lot paving. Drainage Yes Yes Crews are installing drainage on the east side of building C in the area of the truck loading bay. I inspected the pipe connections for backfilling. The northwest type 1 catch basin pipe on the south side of the structure was not completely grouted in. I pointed it out and the crews said that they will patch the gap under the pipe. There were also a couple interior pipe connection that were not grouted yet. I told the crew that they were ok to backfill once the pipe connection is completely grouted. I will return tomorrow to check on the two interior pipe connections that were not complete. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A Page 2 TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/21/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Lighting conduit & junction Yes Yes Crews are placing conduit and junction boxes for boxes Building B parking lot lighting adjacent to 67th Ave. There is a conflict with the water line at one location. See the inspector comments below. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS There is a conflict with a luminaire base and an existing water line. See the top right photo in the Work Performed section of this report. I spoke with Nova Heaton about the conflict. The solution agreed to is to move the location of the luminaire bases/conduit and block wall to accommodate the water line. This should be noted in the as-built drawings. Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/26/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Asphalt Paving Yes No Crews are paving the parking lot and driving areas around Building B. See inspector comments for details. Drainage Yes Yes Crews are installing roof drainage on the east side of Building C. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A Page 2 CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Asphalt Paving: Crews placed (2) 2â€ lifts of HMA for the driving areas of the building lot and 2.5â€ of HMA in the parking areas. The mix design was not per plan. See the photo of the HMA ticket. I spoke with Nova Heaton about the mix being used. She informed me that the mix should be fine for this application. The plans call for 91% compaction on the HMA. There was no testing taking place on site though. I spoke with the foreman about it, and he said that they do not do nuclear gauge density testing for parking lots. He informed me that they use industry standards and compacting methods, and that he was not concerned about reaching 91% compaction. He also informed me that there is a warranty that goes with the paving work. If there are quality issues, they can be resolved through that process. Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/27/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Asphalt Paving Yes No Crews are paving the parking lot and driving areas around Building B. See inspector comments for details. Drainage Yes Yes Crews are installing roof drainage on the west side of Building C. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A Page 2 INSPECTOR COMMENTS Asphalt Paving: Crews placed (2) 2â€ lifts of HMA for the driving areas of the building lot and 2.5â€ of HMA in the parking areas. There was no HMA density testing being performed. See the inspector comments from the daily report dated 5/26/2020. Drainage: I inspected the drainage connections in the photos above. The crews still need to make another connection to the roof drainage before final buy off for backfilling. Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/28/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing building drainage connection for Building C Pavement Marking Yes Yes Crews are painting the parking lot and driving areas of Building B. See inspector notes. Illumination Conduit Yes Yes Crews are installing illumination conduit along the west side of Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A Page 2 INSPECTOR COMMENTS Pavement Marking: Pavement markings were placed per plan, but not all of the surfaces were prepped appropriately. Some of the markings were placed on top of dirty pavement. See the photo on the bottom right corner of page 1 of this report for an example. Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 5/29/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing roof drainage on the west side of Building C. Curb Yes Yes Crews repaired a section of concrete curb that was damaged during the HMA paving work. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/1/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are placing roof drainage for the west side of Building C. The foreman told me that they would be ready for an inspection tomorrow. Concrete Sidewalk Yes Yes Crews are forming and placing concrete for the sidewalk section between the 67th Pedestrian Trail and the parking areas on the west side of Building C. Landscaping/Irrigation Yes Yes Crews are installing irrigation for the landscaping. CC TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A Page 2 TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/2/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are completing roof drainage runs on the west side of Building C. (Inspection Performed) Irrigation Yes Yes Crews are installing irrigation around Building B. Flatwork N/A N/A Crews are forming for the concrete pad on the east side of Building C. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/3/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Irrigation Yes Yes Crews continue installing irrigation around Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/4/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Concrete Loading Slab Yes Yes Crews placed concrete for the Building C loading bay area. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/5/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are making drainage connections for the catch basins with filter packs & and oil water separator on the north side of the Building C Infiltration gallery. See the inspection form below. This inspection was for the pipe connections only, not the filter pack installation or the oil water separator. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/8/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing the drainage run for Building C adjacent to 67th. Reinforcing Steel & Forms Yes Yes Crews are placing rear and forms for the decorative wall along 67th in front of Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/9/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing the drainage run for Building C adjacent to 67th. I inspected the outside connections of the catch basins so that the crews could begin backfilling. There are several inlets that still need the interior connections completed. Power connection Yes Yes PUD crews are establishing power to the property. Page 2 TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Flagger Controlled Double Lane Yes Crews have 67th reduced to 1 lane. See the photos below. Closure (67th) Flaggers are on site and the traffic control devices are set appropriately. Page 3 TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 4 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/10/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing lot drainage on the south side of Building C. Wall/Enclosure Concrete Yes Yes Crews are placing rebar and forms for the dumpster enclosures behind Buildings B and C. Crews area also placing rebar for the screening wall in front of Building B. Page 2 TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 3 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/11/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews finish installing lot drainage on the south side of Building C. Wall/Enclosure Concrete Yes Yes Crews are placing concrete for the dumpster enclosures behind Buildings B and C. Crews area also placing concrete for the screening wall in front of Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/12/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Drainage Yes Yes Crews are installing roof drainage on the south side of Building C. Wall/Enclosure Concrete Yes Yes Crews are stripping forms. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/15/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building Work N/A N/A Building work only. No civil to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/16/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Water Line Installation Yes Yes Crews are installing water line for Building C Decorative Wall Yes Yes Crews are filling form holes and finishing the surface of the decorative wall in front of Building B. HMA Demo Yes N/A Crews are removing the existing HMA access for the property to the north. The contractor will be repaving the driveway. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/17/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Building work N/A N/A Building work only. No civil to report. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/19/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Screen Wall Yes Yes Crews are filling form holes and prepping the surface of the concrete for the brick facia. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/22/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Screen Wall Yes Yes Crews are filling form holes and prepping the surface of the concrete for the brick facia. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Trail Detour/Lane Shift Yes Crews have set up a lane shift to close the northbound 67th Lane so that trail traffic can be detoured into that lane. Crews have closed the trail to remove a portion of it and replace a curb cut with curb and gutter. This will be a long term closure. TEMPORARY EROSION & SEDIMENT CONTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/23/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Demolition Yes N/A Crews are removing existing trail and curb cuts. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜’ - Yes â˜ - No Is the contractor maintaining the traffic control devices? â˜’ - Yes â˜ - No â˜ - N/A CLOSURE TYPE APPROVED NOTES PLAN? Trail Closure/Lane Shift Yes Crews are maintaining the northbound lane shift/trail detour until the new trail and Building C access is complete. TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS Existing Conduit: There is an unidentified section of pipe at the existing driveway cut in front of Building C. I checked the as-built plans at the office. It appears to be a section of conduit for future use that is shown on the as-built plans for 67th. The conduit is supposed to be buried 18â€. But it is actually at about 6â€. The crews will need to remove it to complete their work. I will check with public works to see if the conduit should be replaced. Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/24/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Irrigation Yes Yes Crews are installing irrigation in front of Building B. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/25/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Water Line Installation Yes Yes Crews are installing water line. Public works is on site inspecting the installation. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Department of Community & Economic Development CIVIL INSPECTION DAILY REPORT PROJECT INFORMATION REPORT DATE PROJECT NAME PREPARED BY 6/26/2020 Gayteway Brian Grieve WORK PERFORMED Was work performed today? â˜’ - Yes â˜ - No TYPE OF WORK PERFORMED APPROVED APPROVED NOTES PLANS? MATERIALS? Water Line Yes Yes Crews continue installing water line for Building C. Public works in on site inspecting that work. TEMPORARY TRAFFIC CONTROL Was Temporary Traffic Control required? â˜ - Yes â˜’ - No Is the contractor maintaining the traffic control devices? â˜ - Yes â˜ - No â˜’ - N/A CLOSURE TYPE APPROVED NOTES PLAN? N/A TEMPORARY EROSION & SEDIMENT CNTROL Are the contractorâ€™s erosion control measures in place? â˜’ - Yes â˜ - No Is the contractor maintaining erosion control BMPs? â˜’ - Yes â˜ - No â˜ - N/A EROSION CONTROL ISSUE NOTES N/A INSPECTOR COMMENTS None Page 2 Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21238 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 1 Sample Type: D - Drinking Water Date Collected: 3/31/20 09:03 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #1 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21239 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 2 Sample Type: D - Drinking Water Date Collected: 3/31/20 09:15 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #1 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21240 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 3 Sample Type: D - Drinking Water Date Collected: 3/31/20 09:42 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #2 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21241 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 4 Sample Type: D - Drinking Water Date Collected: 3/31/20 10:20 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Hyd #2 Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21242 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 5 Sample Type: D - Drinking Water Date Collected: 3/31/20 10:54 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Blowoff Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-10869 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21243 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 6 Sample Type: D - Drinking Water Date Collected: 3/31/20 11:06 Sample Purpose: Investigative or Other Date Received: 3/31/20 Sample Location: Blowoff Date Set: 3/31/20 17:05 County: Snohomish Date Analyzed: 4/1/20 13:02 Sampled By: Augusto Tararan Report Date: 4/1/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200331b 3 E. COLI Absent per 100mL SM9223 B m_200331b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-11326 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21979 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 1 Sample Type: D - Drinking Water Date Collected: 4/3/20 08:47 Sample Purpose: Investigative or Other Date Received: 4/3/20 Sample Location: Fire Line Date Set: 4/3/20 12:20 County: Snohomish Date Analyzed: 4/4/20 15:28 Sampled By: Augusto Tararan Report Date: 4/6/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jln SM9223 B m_200403sure 3 E. COLI Absent per 100mL SM9223 B m_200403sure If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-11326 154 W Cox Avenue Project: Gateway Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-21980 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 2 Sample Type: D - Drinking Water Date Collected: 4/3/20 08:50 Sample Purpose: Investigative or Other Date Received: 4/3/20 Sample Location: Fire Line Date Set: 4/3/20 12:20 County: Snohomish Date Analyzed: 4/4/20 15:28 Sampled By: Augusto Tararan Report Date: 4/6/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jln SM9223 B m_200403sure 3 E. COLI Absent per 100mL SM9223 B m_200403sure If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-15585 154 W Cox Avenue Project: Gateway Fire Hydrtant Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-29955 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 1 Sample Type: D - Drinking Water Date Collected: 5/13/20 10:03 Sample Purpose: Investigative or Other Date Received: 5/13/20 Sample Location: Date Set: 5/13/20 17:52 County: Snohomish Date Analyzed: 5/14/20 12:43 Sampled By: Augusto Tararan Report Date: 5/15/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200513b 3 E. COLI Absent per 100mL SM9223 B m_200513b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov Burlington, WA Corporate Laboratory (a) Portland, OR Microbiology/Chemistry (c) 1620 S Walnut St - Burlington, WA 98233 - 800.755.9295 â€¢ 360.757.1400 9150 SW Pioneer Ct Ste W - Wilsonville, OR 97070 - 503.682.7802 Bellingham, WA Microbiology (b) Corvallis, OR Microbiology/Chemistry (d) 805 Orchard Dr Ste 4 - Bellingham, WA 98225 - 360.715.1212 1100 NE Circle Blvd, Ste 130 - Corvallis, OR 97330 - 541.753.4946 Bend, OR Microbiology (e) 20332 Empire Blvd Ste 4 - Bend, OR 97701 - 541.639.8425 Page 1 of 1 Washington State Department of Health WATER BACTERIOLOGICAL ANALYSIS Client Name: Arlington City, Water Reference Number: 20-15585 154 W Cox Avenue Project: Gateway Fire Hydrtant Arlington, WA 98223 System Name: ARLINGTON WATER DEPT Repeat Sample Number: System ID Number: 02950K Lab Number: 164-29956 DOH Source Number: 00 - Distribution Sample (Bacteria) Field ID: 2 Sample Type: D - Drinking Water Date Collected: 5/13/20 10:10 Sample Purpose: Investigative or Other Date Received: 5/13/20 Sample Location: Date Set: 5/13/20 17:52 County: Snohomish Date Analyzed: 5/14/20 12:43 Sampled By: Augusto Tararan Report Date: 5/15/20 Sampler Phone: 360-403-3533 Comment: Approved By: ckk,rml Authorized by: Ceann K Knox Lab Manager, Bellingham DOH# PARAMETER RESULT Qualifier* UNITS Analyst METHOD Batch COMMENT 1 TOTAL COLIFORM Satisfactory, Coliforms Absent per 100mL jfh SM9223 B m_200513b 3 E. COLI Absent per 100mL SM9223 B m_200513b If the sample is unsatisfactory you can get information at the following health department websites or phone numbers: Island Co: http://www.islandcounty.net/health/Envh/DrinkingWater/index.htm San Juan Co: http://www.sanjuanco.com/health/ehswater.aspx Skagit Co: http://www.skagitcounty.net/drinkingwater or 360-336-9380 Snohomish Co: 425-339-5250 Whatcom Co: http://www.co.whatcom.wa.us/health/environmental/drinking_water/index.jsp WSDOH: http://www.doh.wa.gov/ehp/dw/Programs/coliform.htm NOTES: If the result is Unsatisfactory, three (3) repeat samples and groundwater source samples are required for Group A Public Water Systems. Private individuals should investigate the cause of the unsatisfactory result and resample. If E. Coli or Fecal Coliform are present in sample do not drink the water until it is properly treated. *If data qualifiers are present, see accompanying Qualifier Definition report. FORM: cBact email: labresults@arlingtonwa.gov CONSTRUCTION PERMIT APPLICATION Community & Economic Development City of Arlington â€¢ 18204 59th Avenue NE â€¢ Arlington, WA 98223 â€¢ Phone (360) 403-3551 CIVIL (TYPE I) ï² GRADING/PAVING/DRAINAGE (TYPE II) ï² RIGHT OF WAY (TYPE III) ï² TYPE I & II ONLY NEW DEVELOPMENT ï² REDEVELOPMENT ï² Project Name: Snohomish County Tax Parcel I.D. #: Project Address / Location: Description of Project: OWNER Name: Address: City: State: Zip: Phone: Email: APPLICANT Name: Address: City: State: Zip: Phone: Email: ENGINEER Name: Address: City: State: Zip: Phone: Email: License #: Expiration: CONTRACTOR Name: Address: City: State: Zip: Phone: Email: License #: Expiration: I, hereby certify that I have read and examined this application, City of Arlington Municipal Code, Standard Plan & Specifications. Performance of the proposed work shall follow all applicable laws and regulations. The owner/applicant shall assume full and complete responsibility for said work and shall be responsible for the acquisition and compliance of all applicable permits and/or authorizations which may include, but not limited to, Right of Way Permit, WSDW Hydraulic Project Approval (HPA), WSDOE Notice of Intent (NOI), National Pollutant Discharge Elimination System (NPDES), Army Corp. of Engineers Permits, the requirements of the Endangered Species Act, and the Forest Practices Application (FPA). Signature______________________________________________________________________________________________________________________________________ Print Name:_______________________________________________________________Daniel B. Taylor, Architect ____________________________ Date:__________________APRIL 10, 2019________________ Page 1 of 2 REV 10/2017 Complete package constitutes all items. Only complete submittals will be accepted. Civil - Submittal Requirements, Type I: ï² Complete Application; ï² Construction Plans including cut / fill quantities; ï‚§ 2 full size plan sets 22â€ x 34â€ ï‚§ PDF file of the complete plan set ï‚§ 1 full size set of landscape plans 22â€ x 34â€ ï² Marysville Utility plans if applicable (2 sets); ï² Drainage Analysis including calculations and downstream analysis (2 sets) and (PDF file); refer to Stormwater Drainage Requirements; ï² Geotechnical Report (2 sets) and (PDF file); ï² SEPA is required if 500 or more cubic yards of cut / fill is proposed (not required if included with a Land Use Permit); ï² Grading cut / fill quantity: _______________________________; ï² Drafts of easement(s) dedication(s), and/or CAPE(s) for review; ï² Flood Hazard Permit Application and required documentation if project is within 100 year flood plain; refer to Flood Hazard guidance documents; ï² Construction Calculation Worksheet; ï² NPDES Permit (if required); See Storm Water Drainage Report, New or Redevelopment Flowcharts; ï² Assurance Device will be required prior to Permit Issuance (Bond or Assignment of Funds); ï² Plan Check Fee due at time of permit submittal. Grading / Paving / Drainage Submittal Requirements, Type II: ï² Complete Application; ï² Construction Plans including import/export quantities; ï‚§ 2 full size plan sets 22â€ x 34â€ ï‚§ PDF file of the complete plan set ï² Drainage Analysis including calculations and downstream analysis (2 sets) and (PDF file); refer to Stormwater Drainage Requirements; ï² Geotechnical Report (2 sets) and (PDF file); ï² SEPA is required if 500 or more cubic yards of cut/fill is proposed (not required if included with a Land Use Permit); ï² Grading cut / fill quantity: _______________________________; ï² Construction Calculation Worksheet; ï² NPDES Permit (if required); See Storm Water Drainage Report, New or Redevelopment Flowcharts; ï² Plan Check Fee due at time of permit submittal. Right of Way Submittal Requirements, Type III: ï² Complete Application; ï² Construction Plans; ï² Traffic Control Plan; ï² Road Closure Request; ï² Temporary Erosion & Sediment Control (TESC) Plan; ï² Certificate of Insurance with the City of Arlington named as Additional Insured; ï² Assurance Device will be required prior to Permit Issuance (Bond or Assignment of Funds); ï² Engineers Estimated Cost of Construction; $______________________________________; ï² Permit fee due at time of permit issuance. Page 2 of 2 REV 10/2017 UTILITY SERVICE APPLICATION Community & Economic Development City of Arlington â€¢ 18204 59th Avenue NE â€¢ Arlington, WA 98223 â€¢ Phone (360) 403-3551 Application for ï¯ Water ï¯ Sewer Permit Submittal Requirements: ï¯ Completed Application Form ï¯ Site Plan Depicting the Proposal or Civil Permit #_____________ Project Site Address: ______________________________________________________________________________ Property Tax ID#:____________________________________ Subdivision: ________________________________ Occupancy: ï¯ Single Family ï¯ Duplex ï¯ Multi-Family ï¯ Commercial ï¯ Industrial ï¯ Institutional Property Owner: __________________________________________________________________________________ Address: _________________________________________City__________________State________Zip____________ Phone No: _____________________________Email: _____________________________________________________ Contact Person: __________________________________________________________________________________ Address: _________________________________________City__________________State________Zip____________ Phone No: _____________________________Email: _____________________________________________________ Give a brief description of your proposal and/or request: ________________________________________________ Is there a onsite well? ï¯ Yes ï¯ No Is there a onsite septic? ï¯ Yes ï¯ No Will a water meter be required? ï¯ Yes ï¯ No Water meter service size: _________ Total square footage of Building: __________________ Lot/parcel size calculation: _________________ Total square footage of impervious surface (parking lot, building, sidewalks etc.) ___________________________ I hereby certify that the above information is correct and that the construction on, and the occupancy and the use of the above described property will be in accordance with the laws, rules and regulations of the State of Washington. APRIL 10, 2019 ___________________________________________________ __________________________ Applicantâ€™s Signature Date ___________________________________________________ Daniel B. Taylor, Architect Print Applicantâ€™s name Revised 03/2015 T ERRA F ORMA DES I GN GROUP STORM DRAINAGE REPORT _______________________________________________________________________ GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ LOCATION: 20015 67TH AVENUE NE ARLINGTON, WA 98223 ISSUE DATE: March 5, 2019 PREPARED FOR: GAYTEWAY, LLC Contact: Chris Gayte Phone: (206) 240-9739 3/5/19 C I V I L E N G I N E E R I N G & L A N D S C A P E A R C H I T E C T U R E 5027 51st Avenue SW Seattle WA 98136 phone 206.923.0590 website www.terraformadesigngroup.com GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ TABLE OF CONTENTS 1. PROJECT OVERVIEW & MAPS 1 2. EXISTING CONDITIONS SUMMARY 3 3. OFF-SITE ANALYSIS REPORT 6 4. SUMMARY OF MINIMUM REQUIREMENTS 6 5. PERMANENT STORMWATER CONTROL PLAN 10 6. CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN 17 7. SPECIAL REPORTS & STUDIES 17 8. OTHER PERMITS 17 9. OPERATION MAINTENANCE MANUAL, SOURCE CONTROL 17 10. BOND QUANTITIES WORKSHEET 17 APPENDIX A â€“ WWHM CALCULATIONS APPENDIX B â€“ INFILTRATION STUDY AND GEOTECHNICAL REPORT APPENDIX C â€“ STORM OPERATION & MAINTENANCE MANUAL APPENDIX D - CIVIL DESIGN GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 1 - PROJECT OVERVIEW AND MAPS This Storm Drainage Report for the Gayteway Business Park â€“ Building â€˜Bâ€™ has been submitted to the City of Arlington as part of our Civil Permit submittal. Project Proponent: Gayteway, LLC Property Area: 3.52 acres (Lot 2 of proposed BLA) Total Parcel Area: 54 acres Site Location: 20015 67th Avenue NE, Arlington, WA 98223 NW Â¼ & SW Â¼ of SE1/4 of SEC. 14, T31N, R5E, City of Arlington, Snohomish County Parcel ID: 31051400200700 Required Permits: SEPA, Grading Permit, Building Permit The proposed development consists of a new office / warehouse / manufacturing building located at 20015 67th Avenue NE. The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 (west side of railroad tracks) and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The proposed adjacent Building â€˜Câ€™ development has already been submitted to the City for permit. Work includes the proposed site clearing, grading, paving, structures, drainage, utilities, road improvements and landscaping. The existing property was previously used for lumber operations and has since be vacated and structures cleared. The project will require drainage review from the City of Arlington and compliance with the 2014 Washington State Department of Ecology Surface Water Management Manual for Western Washington. Since the development includes greater than 5000 sf of New Impervious Surface, all 10 Min. Technical Requirements apply. Onsite drainage improvements includes new catch basins and storm drainage for surface runoff. Stormwater infiltration will be proposed for the proposed parking, landscaping and roof drainage runoff; underground infiltration chambers are proposed at this time. Basic Runoff Treatment will be provided for the pavement areas via a Bayfilter treatment system prior to discharge to infiltration galleries. A separate drainage report will be prepared for the Building â€˜Câ€™ development to the south. The developer intends to building both buildings and sites concurrently. Page 1 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ 20015 67th Avenue NE, Arlington, WA 98223 NW Â¼ & SW Â¼ of SE1/4 of SEC. 14, T31N, R5E, City of Arlington, Snohomish County Page 2 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 2 - EXISTING CONDITIONS SUMMARY The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The existing property was previously used for lumber operations and has since be vacated and structures cleared. The site is predomimately exposed soil. The property slopes slightly to the north at an average gradient of 1.5 percent. There are several catch basins and storm drains which collect runoff. Drainage is discharged to an existing infiltration pond within Lot 3 at the northeast corner of the property. The pond may be removed with the future Building B development. The site receives minimal drainage from adjacent properties. The property is not within the 100-yr floodplain. We do not know of any onsite or nearby wetlands or sensitive areas. Portage Creek is approximately one-half mile downstream to the northwest. The existing soils are classified as Everett Very Gravelly Sany Loam, 0- to 8 percent slopes according to the National Cooperative Soil Survey by the USDA Natural Resources Conservation Service. These soils are generally consist of very gravelly sandy loam. Depth to densic material is is greater than 80 inches depth. The soils belong to Hydraulic Soil Group â€˜Aâ€™. A Soil Infiltration Rate study was prepared by Sondergaard Geoscience, PLLC, dated April 24, 2018. Twelve exploration pits we done over the 8.3 acre portion west of the railroad tracks. Existing soils generally consisted of crushed rock fill over some pockets of wood fill over Recessional Outwash. The outwash material was encountered to depths of 9 to 14 feet below grade and consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. Groundwater seepage was not encountered with the exception of pit EP-9 (at 6.5-ft depth near the NE corner of the 8.3 acre property). Infiltration rates were measured using grain size analyses at six (6) planned infiltration locations. Rates varied from 38 to 568 in/hr with test depths of 7 to 9 feet. The proposed Building â€˜Câ€™ infiltration gallery is located at approximately Sample Location I-2. The design infiltration data is as follows: Sample Location: I-2 Sample Depth: 7 ft Infiltration Rate: 38 in/hr (uncorrected) Correction Factor: 0.36 (per Snohomish County Drainage Manual, Vol III, Ch. 3.3.6) Design Infilt. Rate: 13.68 in/hr See Appendix B for the infiltration study and geotechnical report. Page 3 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ EXISTING SITE AERIAL & SOIL IDENTIFIER Page 4 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SNOHOMISH COUNTY PARCEL MAP Depicts Entire 54 acre Parcel Page 5 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 3 - OFFSITE ANALYSIS REPORT The property slopes slightly to the north at an average gradient of 1.5 percent. The site receives minimal drainage from adjacent properties. The onsite drainage discharges to an existing infiltration pond at the northeast corner of the Lot 3 to the north. Drainage within 67th Avenue NE continues northward and likely outfalls to Portage Creek approximately one-half mile downstream. We do not know of any drainage problems associated with the downstream system. SECTION 4 - SUMMARY OF MINUMUM REQUIREMENTS 10 Minimum Technical Requirements as provided within Vol. 1, Section 2 of the DOE Manual: Minimum Requirement #1 â€“ Stormwater Site Plan This Storm Drainage Report and the Civil Plans address the temporary and permanent drainage impacts of the project. Minimum Requirement #2 â€“ Construction Stormwater Pollution Prevention Plan An Erosion Control Plan and Construction Stormwater Pollution Prevention Plan (CSWPPP) will be prepared for the contractor. A Department of Ecology Construction Stormwater Permit will not be obtained onsite drainage will be retained onsite. Minimum Requirement #3 - Source Control of Pollution The proposed business park site is a relatively low pollution generator. General source control pollution prevention plans and a storm operation and maintenance manual with the final permit submittal. Minimum Requirement #4 â€“ Preservation of Natural Drainage Systems and Outfalls Onsite drainage will continue to be retained onsite. Minimum Requirement #5 â€“ On-Site Stormwater Management As required by the 2014 SWMMWW, On-Site Stormwater Management is required where feasible based on site conditions. A Stormtech chamber & rock gallery will be proposed to infiltrate the site runoff. We expect to meet the LID Duration standard such that no further Stormwater Management practices will be required. Page 6 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Minimum Requirement #6 â€“ Runoff Treatment The proposed business park will trigger Enhanced Treatment for all pollution generating surfaces. Since the infiltration facilities are greater than Â¼ mile upstream of Portage Creek, Basic Runoff Treatment via Contech Storm filters should be acceptable prior to discharge to the infiltration chamber gallery. Roof runoff will bypass the treatment system. Minimum Requirement #7 â€“ Flow Control Infiltration chambers are proposed to retain all development runoff. Runoff will discharge into the native Everett Very Gravelly Sandy Loam soils, with a Design Infiltration Rate of 13.68 in/hr. Minimum Requirement #8 â€“ Wetlands Protection There are no wetlands within the proposed development area or immediate vicinity. Minimum Requirement #9 - Basin / Watershed Planning We do not know of any local basin or watershed planning. Minimum Requirement #10 â€“ Operation and Maintenance A Stormwater Operation Maintenance Manual and site Source Control measures are included. Page 7 Page 8 Page 9 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 5 - PERMANENT STORMWATER CONTROL PLAN The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The proposed Building â€œBâ€ development will include approximately 3.20 acres of impervious area of the 3.52 acre Lot 2 parcel. The development will trigger Enhanced Treatment for all pollution generating surfaces. Since the infiltration facilities are greater than Â¼ mile upstream of Portage Creek, Basic Runoff Treatment via a Bayfilter Treatment Manhole should be acceptable for Runoff Treatment prior to discharge to the flow control facility. Roof runoff will bypass the treatment system. Runoff Flow Control will be required. Underground infiltration chambers by Stormtech are proposed to retain all development runoff. Infiltration Gallery â€˜Aâ€™ is proposed at the northwest corner of the site to service all pavement areas, landscape areas and most of the roof area. Infiltration Gallery â€˜Bâ€™ is located near the northeast corner of the building and designed to serve the east side of the building roof (0.62 acres). Runoff will infiltrate into the native Everett Very Gravelly Sandy Loam soils, with an expected Design Infiltration Rate of 13.68 in/hr. At this time, the bottom of the Infiltration Gallery â€œAâ€ is approximately 13 feet below existing and proposed grades. We are confident that the existing subsoils are consistent with the sample soils at 7 foot depth. Additional infiltration tests will be peformed at the start of site construction. See attached basin data and infiltration system summary. Sizing calculations were provided via the Western Washington Hydrologic Method (WWHM) within computer output provided within Appendix A. We will meet LID Duration Control to meet the intent of onsite Stormwater Management requirements as a result of our onsite underground infiltration galleries. Page 10 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ STORMWATER DATA - BASIN 'A' Project Name: GAYTEWAY - BULDING 'B' By: P.A.D. Project Number: 18005 Date: 3/4/19 DRAINAGE CRITERIA: CITY OF ARLINGTON RAINFALL METHOD: WWHM Step 1) Site Data 1) General characteristics: Basin A Soil type outwash Development type commercial Soil Group A Size (ac.) 2.68 Existing surface soil, paving Detention/Retention Retention Predev Cover forest 2) Existing onsite characteristics: forest 2.68 acres Assume forested per DOE Manual 3) Developed onsite characteristics: landscape 0.24 acres Impervious acres: 2.44 acres roof 0.85 acres walks 0.07 acres paving 1.52 acres Step 3) Developed stormwater discharge criteria 1. Flow control required. Infiltration all site runoff. the range of pre-developed discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow. 2. Basic Runoff Treatment provided to meet the 91% storm event. Step 4) Flow Control Facility Proposed 39 qty ~ Stormtech MC-3500 chambers in 107' X 23' rock gallery 100% onsite retention provided Page 11 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Page 12 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ STORMWATER DATA - BASIN 'B' Project Name: GAYTEWAY - BULDING 'B' By: P.A.D. Project Number: 18005 Date: 3/4/19 DRAINAGE CRITERIA: CITY OF ARLINGTON RAINFALL METHOD: WWHM Step 1) Site Data 1) General characteristics: Basin B Soil type outwash Development type commercial Soil Group A Size (ac.) 0.62 Existing surface soil, paving Detention/Retention Retention Predev Cover forest 2) Existing onsite characteristics: Pervious acres 0.62 acres forest 0.62 acres Assume forested per DOE Manual Impervious acres 0.00 acres pavement 0.00 acres 3) Developed onsite characteristics: Pervious acres 0.00 acres landscape 0.00 acres Impervious acres: 0.62 acres roof 0.62 acres paving 0.00 acres Step 3) Developed stormwater discharge criteria 1. Flow control required. Infiltration all runoff Step 4) Flow Control Facility Proposed 12 qty ~ Stormtech MC-3500 chambers in 53' X 16' rock gallery 100% onsite retention. Page 13 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Page 14 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ WATER QUALITY TREATMENT CALCULATIONS Project Name: GAYTEWAY - BULDING 'B' By: P.A.D. Project Number: 18005 Date: 3/5/19 DRAINAGE CRITERIA: CITY OF ARLINGTON RAINFALL METHOD: WWHM CB #4 - BAYFILTER MH Step 1) Calculate design flows Alandscape= 0.24 ac Awalks= 0.07 ac Apaving= 1.52 ac WWHM results Water Quality BMP Flow and Volume for POC 3 . On-line facility volume: 0.1984 acre-feet On-line facility target flow (15min): 0.3031 cfs. Off-line facility target flow (15min): 0.1717 cfs. If no high flow bypass: Q25 1.760 cfs Water quality flow: Qwq 0.172 cfs "Off-Line" treatment, 15min Flow Rate Use internal bypass structure inside MH Step 2) Calculate Number of Cartridges Use Bayfilter treatment cartridges, Model: 545 Invert Drop (in) = 2.83 Treatment Rate (gpm / cart)= 45 N = Number of Cartridges = Qwq * 449 gpm / cfs / (treatment rate) = 1.72 ===> USE 2 CARTRIDGES -BAYFILTER 545 CARTRIDGE USE 72" DIA. BAYFILTER MH W/ INTERNAL BYPASS Page 15 Q/Qf Vf Q/Qf < 1.0, <ok> Qf s n R DIA ) and I = P * i R Q P.A.D.3/5/19 * Tc^(-b By: Date: R I = a iR Tc CAtot 0.63 = bR CA C CONVEYANCE SYSTEM DESIGN = 2.66 aR A GAYTEWAY - BLDG C18005CITY OF ARLINGTONRATIONAL METHOD25YR / 24HR TO10 1817160.0715140.24130.110.85120.11100.210.9040.000.900.060.170.9080.150.9070.220.100.9060.100.100.060.9040.100.900.180.190.220.90240.110.000.820.32210.106.30.150.410.100.140.830.60226.30.090.850.60202.50.086.30.270.850.766.30.100.870.89312.50.156.30.9822.50.096.30.170.151.120.902.50.096.30.030.90292.50.096.30.540.15282.56.30.120.790.240.90276.32.50.000.241.0480.330.9032.50.091.510.416.32.50.191.5182.50.906.30.0120.150.131.8980.900.246.30.030.202.2380.332.56.30.0120.00122.462.50.900.0122.81120.110.152.50.900.00790.000.0126.3120.182.50.900.0126.30.37120.840.00660.0120.61120.170.110.0066122.50.0126.30.820.120.110.00662.50.0126.31.040.181.180.00360.000.01280.170.00360.0122.56.380.611.080.290.00366.32.580.831.080.470.00360.01280.471.083.30.00500.0122.56.30.382.340.00802.50.0126.30.4582.343.10.0126.382.340.00663.16.32.50.272.340.00660.133.12.50.0120.2762.760.00803.02.50.0123.4960.14573.00.502.50.433.00.730.0121.080.7263.00.960.01000.01261.081.170.643.50.01001.171.194.40.640.0125.0660.810.01000.01283.10.950.081783.11.330.890.01280.803.41.330.01000.01214.40.01000.0120.350.620.0120.561.763.80.01000.693.80.01000.210.620.01030.620.29103.10.468.90.620.631.333.13.11.340.627.150.263.10.443.80.443.820.30.700.540.870.16 3.0 P(in) = 11 191817161514131210 9 8 7 6 2524 2322 3231 30292827 18005-Storm-CLC-B.xls,CONVEY FROM Project Name:Project Number:DRAINAGE CRITERIA:RAINFALL METHOD:DESIGN STORM: Page 16 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 6 - CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN An Erosion Control Plan and Construction Stormwater Pollution Prevention Plan is provided with our Civil Permit submittal. SECTION 7 - SPECIAL REPORTS & STUDIES The existing soils are classified as Everett Very Gravelly Sany Loam, 0- to 8 percent slopes according to the National Cooperative Soil Survey by the USDA Natural Resources Conservation Service. Infilration study and geotechnical report provided within Appendix B. SECTION 8 - OTHER PERMITS A Department of Ecology Construction Stormwater Permit will not be applied for since our site will fully retain all site runoff. SECTION 9 - OPERATION MAINTENANCE MANUAL, SOURCE CONTROL A Stormwater Operation Maintenance Manual and site Source Control measures will be provided with the final permit submittal. SECTION 10 - BOND QUANTITIES WORKSHEET A Bond Quantities Worksheet will be submitted with our Civil Permit. Page 17 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX A â€“ WWHM CALCULATIONS A-1 WWHM2012 PROJECT REPORT A-2 General Model Information Project Name: 18005-B-wwhm Site Name: GAYTE BUSINESS PARK Site Address: 20015 67TH AVE NE City: ARLINGTON Report Date: 3/9/2019 Gage: Everett Data Start: 1948/10/01 Data End: 2009/09/30 Timestep: 15 Minute Precip Scale: 1.200 Version Date: 2016/11/23 Version: 4.2.13 POC Thresholds Low Flow Threshold for POC1: 50 Percent of the 2 Year High Flow Threshold for POC1: 50 Year Low Flow Threshold for POC2: 50 Percent of the 2 Year High Flow Threshold for POC2: 50 Year Low Flow Threshold for POC3: 50 Percent of the 2 Year High Flow Threshold for POC3: 50 Year 18005-B-wwhm 3/9/2019 6:31:18 AM Page 2 A-3 Landuse Basin Data Predeveloped Land Use B-1 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 2.68 Pervious Total 2.68 Impervious Land Use acre Impervious Total 0 Basin Total 2.68 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 3 A-4 Basin 2 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 4.42 Pervious Total 4.42 Impervious Land Use acre Impervious Total 0 Basin Total 4.42 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 4 A-5 B-WQ Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 1.83 Pervious Total 1.83 Impervious Land Use acre Impervious Total 0 Basin Total 1.83 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 5 A-6 B-2 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 0.62 Pervious Total 0.62 Impervious Land Use acre Impervious Total 0 Basin Total 0.62 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 6 A-7 Mitigated Land Use Basin A Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.24 Pervious Total 0.24 Impervious Land Use acre ROOF TOPS FLAT 0.85 SIDEWALKS FLAT 0.07 PARKING FLAT 1.52 Impervious Total 2.44 Basin Total 2.68 Element Flows To: Surface Interflow Groundwater StormTech A StormTech A 18005-B-wwhm 3/9/2019 6:31:18 AM Page 7 A-8 WQ Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.24 Pervious Total 0.24 Impervious Land Use acre SIDEWALKS FLAT 0.07 PARKING FLAT 1.52 Impervious Total 1.59 Basin Total 1.83 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 8 A-9 Basin B Bypass: No GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 0.62 Impervious Total 0.62 Basin Total 0.62 Element Flows To: Surface Interflow Groundwater StormTech-B StormTech-B 18005-B-wwhm 3/9/2019 6:31:18 AM Page 9 A-10 Routing Elements Predeveloped Routing 18005-B-wwhm 3/9/2019 6:31:18 AM Page 10 A-11 Mitigated Routing StormTech A Chamber Model: 3500 Dimensions Max Row Length: 110 Number of Chambers: 39 Number of Endcaps: 6 Top Stone Depth: 12 Bottom Stone Depth: 9 Infiltration On Infiltration rate: 38 Infiltration safety factor: 0.36 Total Volume Infiltrated (ac-ft.): 498.335 Total Volume Through Riser (ac-ft.): 0 Total Volume Through Facility (ac-ft.): 498.335 Percent Infiltrated: 100 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 5.5 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 StormTech Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 3.0000 0.098 0.000 0.000 0.000 3.0667 0.098 0.006 0.000 1.358 3.1333 0.098 0.013 0.000 1.358 3.2000 0.098 0.019 0.000 1.358 3.2667 0.098 0.026 0.000 1.358 3.3333 0.098 0.032 0.000 1.358 3.4000 0.098 0.039 0.000 1.358 3.4667 0.098 0.046 0.000 1.358 3.5333 0.098 0.052 0.000 1.358 3.6000 0.098 0.059 0.000 1.358 3.6667 0.098 0.065 0.000 1.358 3.7333 0.098 0.072 0.000 1.358 3.8000 0.098 0.078 0.000 1.358 3.8667 0.098 0.085 0.000 1.358 3.9333 0.098 0.091 0.000 1.358 4.0000 0.098 0.098 0.000 1.358 4.0667 0.098 0.105 0.000 1.358 4.1333 0.098 0.111 0.000 1.358 4.2000 0.098 0.118 0.000 1.358 4.2667 0.098 0.124 0.000 1.358 4.3333 0.098 0.131 0.000 1.358 4.4000 0.098 0.137 0.000 1.358 4.4667 0.098 0.144 0.000 1.358 4.5333 0.098 0.151 0.000 1.358 4.6000 0.098 0.157 0.000 1.358 4.6667 0.098 0.164 0.000 1.358 4.7333 0.098 0.170 0.000 1.358 4.8000 0.098 0.177 0.000 1.358 18005-B-wwhm 3/9/2019 6:31:18 AM Page 11 A-12 4.8667 0.098 0.183 0.000 1.358 4.9333 0.098 0.190 0.000 1.358 5.0000 0.098 0.197 0.000 1.358 5.0667 0.098 0.203 0.000 1.358 5.1333 0.098 0.210 0.000 1.358 5.2000 0.098 0.216 0.000 1.358 5.2667 0.098 0.223 0.000 1.358 5.3333 0.098 0.229 0.000 1.358 5.4000 0.098 0.236 0.000 1.358 5.4667 0.098 0.242 0.000 1.358 5.5333 0.098 0.249 0.000 1.358 5.6000 0.098 0.256 0.000 1.358 5.6667 0.098 0.262 0.000 1.358 5.7333 0.098 0.269 0.000 1.358 5.8000 0.098 0.275 0.000 1.358 5.8667 0.098 0.282 0.000 1.358 5.9333 0.098 0.288 0.000 1.358 6.0000 0.098 0.295 0.000 1.358 6.0667 0.098 0.302 0.000 1.358 6.1333 0.098 0.308 0.000 1.358 6.2000 0.098 0.315 0.000 1.358 6.2667 0.098 0.321 0.000 1.358 6.3333 0.098 0.328 0.000 1.358 6.4000 0.098 0.334 0.000 1.358 6.4667 0.098 0.341 0.000 1.358 6.5333 0.098 0.348 0.000 1.358 6.6000 0.098 0.354 0.000 1.358 6.6667 0.098 0.361 0.000 1.358 6.7333 0.098 0.367 0.000 1.358 6.8000 0.098 0.374 0.000 1.358 6.8667 0.098 0.380 0.000 1.358 6.9333 0.098 0.387 0.000 1.358 7.0000 0.098 0.393 0.000 1.358 7.0667 0.098 0.400 0.000 1.358 7.1333 0.098 0.407 0.000 1.358 7.2000 0.098 0.413 0.000 1.358 7.2667 0.098 0.420 0.000 1.358 7.3333 0.098 0.426 0.000 1.358 7.4000 0.098 0.433 0.000 1.358 7.4667 0.098 0.439 0.000 1.358 7.5333 0.098 0.446 0.000 1.358 7.6000 0.098 0.453 0.000 1.358 7.6667 0.098 0.459 0.000 1.358 7.7333 0.098 0.466 0.000 1.358 7.8000 0.098 0.472 0.000 1.358 7.8667 0.098 0.479 0.000 1.358 7.9333 0.098 0.485 0.000 1.358 8.0000 0.098 0.492 0.000 1.358 8.0667 0.098 0.499 0.000 1.358 8.1333 0.098 0.505 0.000 1.358 8.2000 0.098 0.512 0.000 1.358 8.2667 0.098 0.518 0.000 1.358 8.3333 0.098 0.525 0.000 1.358 8.4000 0.098 0.531 0.000 1.358 8.4667 0.098 0.538 0.000 1.358 8.5333 0.098 0.544 0.064 1.358 8.6000 0.098 0.551 0.333 1.358 8.6667 0.098 0.558 0.703 1.358 18005-B-wwhm 3/9/2019 6:31:18 AM Page 12 A-13 8.7333 0.098 0.564 1.115 1.358 8.8000 0.098 0.571 1.509 1.358 8.8667 0.098 0.577 1.834 1.358 8.9333 0.098 0.584 2.060 1.358 9.0000 0.098 0.590 2.203 1.358 9.0667 0.098 0.597 2.371 1.358 9.1333 0.000 0.000 2.506 0.000 18005-B-wwhm 3/9/2019 6:31:18 AM Page 13 A-14 StormTech-B Chamber Model: 3500 Dimensions Max Row Length: 53 Number of Chambers: 12 Number of Endcaps: 4 Top Stone Depth: 12 Bottom Stone Depth: 9 Infiltration On Infiltration rate: 38 Infiltration safety factor: 0.36 Total Volume Infiltrated (ac-ft.): 119.795 Total Volume Through Riser (ac-ft.): 0 Total Volume Through Facility (ac-ft.): 119.795 Percent Infiltrated: 100 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 5.5 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 StormTech Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 3.0000 0.014 0.000 0.000 0.000 3.0444 0.014 0.000 0.000 0.201 3.0889 0.014 0.001 0.000 0.201 3.1333 0.014 0.001 0.000 0.201 3.1778 0.014 0.002 0.000 0.201 3.2222 0.014 0.003 0.000 0.201 3.2667 0.014 0.003 0.000 0.201 3.3111 0.014 0.004 0.000 0.201 3.3556 0.014 0.005 0.000 0.201 3.4000 0.014 0.005 0.000 0.201 3.4444 0.014 0.006 0.000 0.201 3.4889 0.014 0.007 0.000 0.201 3.5333 0.014 0.007 0.000 0.201 3.5778 0.014 0.008 0.000 0.201 3.6222 0.014 0.009 0.000 0.201 3.6667 0.014 0.009 0.000 0.201 3.7111 0.014 0.010 0.000 0.201 3.7556 0.014 0.011 0.000 0.201 3.8000 0.014 0.011 0.000 0.201 3.8444 0.014 0.012 0.000 0.201 3.8889 0.014 0.013 0.000 0.201 3.9333 0.014 0.013 0.000 0.201 3.9778 0.014 0.014 0.000 0.201 4.0222 0.014 0.014 0.000 0.201 4.0667 0.014 0.015 0.000 0.201 4.1111 0.014 0.016 0.000 0.201 4.1556 0.014 0.016 0.000 0.201 4.2000 0.014 0.017 0.000 0.201 4.2444 0.014 0.018 0.000 0.201 4.2889 0.014 0.018 0.000 0.201 18005-B-wwhm 3/9/2019 6:31:18 AM Page 14 A-15 4.3333 0.014 0.019 0.000 0.201 4.3778 0.014 0.020 0.000 0.201 4.4222 0.014 0.020 0.000 0.201 4.4667 0.014 0.021 0.000 0.201 4.5111 0.014 0.022 0.000 0.201 4.5556 0.014 0.022 0.000 0.201 4.6000 0.014 0.023 0.000 0.201 4.6444 0.014 0.024 0.000 0.201 4.6889 0.014 0.024 0.000 0.201 4.7333 0.014 0.025 0.000 0.201 4.7778 0.014 0.026 0.000 0.201 4.8222 0.014 0.026 0.000 0.201 4.8667 0.014 0.027 0.000 0.201 4.9111 0.014 0.027 0.000 0.201 4.9556 0.014 0.028 0.000 0.201 5.0000 0.014 0.029 0.000 0.201 5.0444 0.014 0.029 0.000 0.201 5.0889 0.014 0.030 0.000 0.201 5.1333 0.014 0.031 0.000 0.201 5.1778 0.014 0.031 0.000 0.201 5.2222 0.014 0.032 0.000 0.201 5.2667 0.014 0.033 0.000 0.201 5.3111 0.014 0.033 0.000 0.201 5.3556 0.014 0.034 0.000 0.201 5.4000 0.014 0.035 0.000 0.201 5.4444 0.014 0.035 0.000 0.201 5.4889 0.014 0.036 0.000 0.201 5.5333 0.014 0.037 0.000 0.201 5.5778 0.014 0.037 0.000 0.201 5.6222 0.014 0.038 0.000 0.201 5.6667 0.014 0.038 0.000 0.201 5.7111 0.014 0.039 0.000 0.201 5.7556 0.014 0.040 0.000 0.201 5.8000 0.014 0.040 0.000 0.201 5.8444 0.014 0.041 0.000 0.201 5.8889 0.014 0.042 0.000 0.201 5.9333 0.014 0.042 0.000 0.201 5.9778 0.014 0.043 0.000 0.201 6.0222 0.014 0.044 0.000 0.201 6.0667 0.014 0.044 0.000 0.201 6.1111 0.014 0.045 0.000 0.201 6.1556 0.014 0.046 0.000 0.201 6.2000 0.014 0.046 0.000 0.201 6.2444 0.014 0.047 0.000 0.201 6.2889 0.014 0.048 0.000 0.201 6.3333 0.014 0.048 0.000 0.201 6.3778 0.014 0.049 0.000 0.201 6.4222 0.014 0.050 0.000 0.201 6.4667 0.014 0.050 0.000 0.201 6.5111 0.014 0.051 0.000 0.201 6.5556 0.014 0.051 0.000 0.201 6.6000 0.014 0.052 0.000 0.201 6.6444 0.014 0.053 0.000 0.201 6.6889 0.014 0.053 0.000 0.201 6.7333 0.014 0.054 0.000 0.201 6.7778 0.014 0.055 0.000 0.201 6.8222 0.014 0.055 0.000 0.201 6.8667 0.014 0.056 0.000 0.201 18005-B-wwhm 3/9/2019 6:31:18 AM Page 15 A-16 6.9111 0.014 0.057 0.000 0.201 6.9556 0.014 0.057 0.000 0.201 7.0000 0.014 0.058 0.000 0.201 7.0444 0.014 0.059 0.000 0.201 7.0889 0.000 0.000 0.000 0.000 18005-B-wwhm 3/9/2019 6:31:19 AM Page 16 A-17 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 7.1 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.24 Total Impervious Area: 2.44 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.008149 5 year 0.017675 10 year 0.028352 25 year 0.049518 50 year 0.073172 100 year 0.106139 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.006 0.000 1950 0.017 0.000 1951 0.012 0.000 1952 0.006 0.000 1953 0.006 0.000 1954 0.039 0.000 1955 0.030 0.000 1956 0.006 0.000 1957 0.006 0.000 1958 0.006 0.000 18005-B-wwhm 3/9/2019 6:31:19 AM Page 17 A-18 1959 0.013 0.000 1960 0.010 0.000 1961 0.027 0.000 1962 0.006 0.000 1963 0.006 0.000 1964 0.019 0.000 1965 0.006 0.000 1966 0.006 0.000 1967 0.011 0.000 1968 0.006 0.000 1969 0.006 0.000 1970 0.006 0.000 1971 0.028 0.000 1972 0.006 0.000 1973 0.006 0.000 1974 0.015 0.000 1975 0.005 0.000 1976 0.013 0.000 1977 0.006 0.000 1978 0.006 0.000 1979 0.011 0.000 1980 0.006 0.000 1981 0.006 0.000 1982 0.008 0.000 1983 0.006 0.000 1984 0.006 0.000 1985 0.010 0.000 1986 0.050 0.000 1987 0.033 0.000 1988 0.006 0.000 1989 0.005 0.000 1990 0.006 0.000 1991 0.006 0.000 1992 0.006 0.000 1993 0.006 0.000 1994 0.005 0.000 1995 0.007 0.000 1996 0.064 0.000 1997 0.176 0.000 1998 0.006 0.000 1999 0.006 0.000 2000 0.011 0.000 2001 0.005 0.000 2002 0.006 0.000 2003 0.004 0.000 2004 0.006 0.000 2005 0.006 0.000 2006 0.189 0.000 2007 0.006 0.000 2008 0.009 0.000 2009 0.006 0.000 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1891 0.0000 2 0.1758 0.0000 3 0.0642 0.0000 18005-B-wwhm 3/9/2019 6:32:35 AM Page 18 A-19 4 0.0500 0.0000 5 0.0391 0.0000 6 0.0328 0.0000 7 0.0296 0.0000 8 0.0276 0.0000 9 0.0267 0.0000 10 0.0186 0.0000 11 0.0166 0.0000 12 0.0149 0.0000 13 0.0129 0.0000 14 0.0128 0.0000 15 0.0118 0.0000 16 0.0113 0.0000 17 0.0111 0.0000 18 0.0106 0.0000 19 0.0104 0.0000 20 0.0095 0.0000 21 0.0086 0.0000 22 0.0084 0.0000 23 0.0067 0.0000 24 0.0057 0.0000 25 0.0057 0.0000 26 0.0057 0.0000 27 0.0057 0.0000 28 0.0057 0.0000 29 0.0057 0.0000 30 0.0057 0.0000 31 0.0057 0.0000 32 0.0057 0.0000 33 0.0057 0.0000 34 0.0057 0.0000 35 0.0057 0.0000 36 0.0057 0.0000 37 0.0057 0.0000 38 0.0057 0.0000 39 0.0057 0.0000 40 0.0057 0.0000 41 0.0057 0.0000 42 0.0057 0.0000 43 0.0057 0.0000 44 0.0056 0.0000 45 0.0056 0.0000 46 0.0056 0.0000 47 0.0056 0.0000 48 0.0056 0.0000 49 0.0056 0.0000 50 0.0056 0.0000 51 0.0056 0.0000 52 0.0056 0.0000 53 0.0056 0.0000 54 0.0056 0.0000 55 0.0055 0.0000 56 0.0055 0.0000 57 0.0055 0.0000 58 0.0055 0.0000 59 0.0053 0.0000 60 0.0049 0.0000 61 0.0039 0.0000 18005-B-wwhm 3/9/2019 6:32:35 AM Page 19 A-20 18005-B-wwhm 3/9/2019 6:32:35 AM Page 20 A-21 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0041 2357 0 0 Pass 0.0048 1323 0 0 Pass 0.0055 433 0 0 Pass 0.0062 112 0 0 Pass 0.0069 102 0 0 Pass 0.0076 89 0 0 Pass 0.0083 77 0 0 Pass 0.0090 66 0 0 Pass 0.0097 61 0 0 Pass 0.0104 58 0 0 Pass 0.0111 54 0 0 Pass 0.0118 50 0 0 Pass 0.0124 49 0 0 Pass 0.0131 47 0 0 Pass 0.0138 43 0 0 Pass 0.0145 40 0 0 Pass 0.0152 36 0 0 Pass 0.0159 36 0 0 Pass 0.0166 32 0 0 Pass 0.0173 31 0 0 Pass 0.0180 31 0 0 Pass 0.0187 29 0 0 Pass 0.0194 29 0 0 Pass 0.0201 27 0 0 Pass 0.0208 26 0 0 Pass 0.0215 26 0 0 Pass 0.0222 26 0 0 Pass 0.0229 25 0 0 Pass 0.0236 23 0 0 Pass 0.0243 23 0 0 Pass 0.0250 23 0 0 Pass 0.0257 23 0 0 Pass 0.0264 23 0 0 Pass 0.0271 21 0 0 Pass 0.0278 19 0 0 Pass 0.0285 18 0 0 Pass 0.0292 17 0 0 Pass 0.0299 16 0 0 Pass 0.0306 16 0 0 Pass 0.0313 15 0 0 Pass 0.0320 15 0 0 Pass 0.0327 14 0 0 Pass 0.0334 13 0 0 Pass 0.0341 13 0 0 Pass 0.0348 13 0 0 Pass 0.0355 13 0 0 Pass 0.0362 13 0 0 Pass 0.0369 13 0 0 Pass 0.0376 13 0 0 Pass 0.0383 13 0 0 Pass 0.0390 13 0 0 Pass 0.0397 11 0 0 Pass 0.0404 11 0 0 Pass 18005-B-wwhm 3/9/2019 6:32:35 AM Page 21 A-22 0.0411 11 0 0 Pass 0.0418 11 0 0 Pass 0.0425 11 0 0 Pass 0.0432 11 0 0 Pass 0.0439 11 0 0 Pass 0.0446 11 0 0 Pass 0.0453 11 0 0 Pass 0.0460 11 0 0 Pass 0.0466 11 0 0 Pass 0.0473 11 0 0 Pass 0.0480 11 0 0 Pass 0.0487 10 0 0 Pass 0.0494 10 0 0 Pass 0.0501 9 0 0 Pass 0.0508 9 0 0 Pass 0.0515 8 0 0 Pass 0.0522 8 0 0 Pass 0.0529 8 0 0 Pass 0.0536 8 0 0 Pass 0.0543 8 0 0 Pass 0.0550 8 0 0 Pass 0.0557 8 0 0 Pass 0.0564 8 0 0 Pass 0.0571 8 0 0 Pass 0.0578 8 0 0 Pass 0.0585 8 0 0 Pass 0.0592 8 0 0 Pass 0.0599 8 0 0 Pass 0.0606 8 0 0 Pass 0.0613 8 0 0 Pass 0.0620 7 0 0 Pass 0.0627 7 0 0 Pass 0.0634 7 0 0 Pass 0.0641 7 0 0 Pass 0.0648 6 0 0 Pass 0.0655 6 0 0 Pass 0.0662 6 0 0 Pass 0.0669 6 0 0 Pass 0.0676 6 0 0 Pass 0.0683 6 0 0 Pass 0.0690 6 0 0 Pass 0.0697 6 0 0 Pass 0.0704 6 0 0 Pass 0.0711 6 0 0 Pass 0.0718 6 0 0 Pass 0.0725 5 0 0 Pass 0.0732 5 0 0 Pass 18005-B-wwhm 3/9/2019 6:32:35 AM Page 22 A-23 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0.4876 acre-feet On-line facility target flow: 0.7522 cfs. Adjusted for 15 min: 0.7522 cfs. Off-line facility target flow: 0.4268 cfs. Adjusted for 15 min: 0.4268 cfs. 18005-B-wwhm 3/9/2019 6:32:35 AM Page 23 A-24 LID Report 18005-B-wwhm 3/9/2019 6:32:35 AM Page 24 A-25 POC 2 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #2 Total Pervious Area: 0.62 Total Impervious Area: 0 Mitigated Landuse Totals for POC #2 Total Pervious Area: 0 Total Impervious Area: 0.62 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #2 Return Period Flow(cfs) 2 year 0.000712 5 year 0.001543 10 year 0.002476 25 year 0.004324 50 year 0.00639 100 year 0.009268 Flow Frequency Return Periods for Mitigated. POC #2 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #2 Year Predeveloped Mitigated 1949 0.000 0.000 1950 0.001 0.000 1951 0.001 0.000 1952 0.000 0.000 1953 0.000 0.000 1954 0.003 0.000 1955 0.003 0.000 1956 0.000 0.000 1957 0.000 0.000 1958 0.000 0.000 1959 0.001 0.000 18005-B-wwhm 3/9/2019 6:33:37 AM Page 25 A-26 1960 0.001 0.000 1961 0.002 0.000 1962 0.000 0.000 1963 0.000 0.000 1964 0.002 0.000 1965 0.000 0.000 1966 0.000 0.000 1967 0.001 0.000 1968 0.000 0.000 1969 0.000 0.000 1970 0.000 0.000 1971 0.002 0.000 1972 0.000 0.000 1973 0.000 0.000 1974 0.001 0.000 1975 0.000 0.000 1976 0.001 0.000 1977 0.000 0.000 1978 0.000 0.000 1979 0.001 0.000 1980 0.000 0.000 1981 0.000 0.000 1982 0.001 0.000 1983 0.000 0.000 1984 0.000 0.000 1985 0.001 0.000 1986 0.004 0.000 1987 0.003 0.000 1988 0.000 0.000 1989 0.000 0.000 1990 0.000 0.000 1991 0.000 0.000 1992 0.000 0.000 1993 0.000 0.000 1994 0.000 0.000 1995 0.001 0.000 1996 0.006 0.000 1997 0.015 0.000 1998 0.000 0.000 1999 0.000 0.000 2000 0.001 0.000 2001 0.000 0.000 2002 0.000 0.000 2003 0.000 0.000 2004 0.000 0.000 2005 0.000 0.000 2006 0.017 0.000 2007 0.000 0.000 2008 0.001 0.000 2009 0.000 0.000 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #2 Rank Predeveloped Mitigated 1 0.0165 0.0000 2 0.0153 0.0000 3 0.0056 0.0000 4 0.0044 0.0000 18005-B-wwhm 3/9/2019 6:34:12 AM Page 26 A-27 5 0.0034 0.0000 6 0.0029 0.0000 7 0.0026 0.0000 8 0.0024 0.0000 9 0.0023 0.0000 10 0.0016 0.0000 11 0.0015 0.0000 12 0.0013 0.0000 13 0.0011 0.0000 14 0.0011 0.0000 15 0.0010 0.0000 16 0.0010 0.0000 17 0.0010 0.0000 18 0.0009 0.0000 19 0.0009 0.0000 20 0.0008 0.0000 21 0.0008 0.0000 22 0.0007 0.0000 23 0.0006 0.0000 24 0.0005 0.0000 25 0.0005 0.0000 26 0.0005 0.0000 27 0.0005 0.0000 28 0.0005 0.0000 29 0.0005 0.0000 30 0.0005 0.0000 31 0.0005 0.0000 32 0.0005 0.0000 33 0.0005 0.0000 34 0.0005 0.0000 35 0.0005 0.0000 36 0.0005 0.0000 37 0.0005 0.0000 38 0.0005 0.0000 39 0.0005 0.0000 40 0.0005 0.0000 41 0.0005 0.0000 42 0.0005 0.0000 43 0.0005 0.0000 44 0.0005 0.0000 45 0.0005 0.0000 46 0.0005 0.0000 47 0.0005 0.0000 48 0.0005 0.0000 49 0.0005 0.0000 50 0.0005 0.0000 51 0.0005 0.0000 52 0.0005 0.0000 53 0.0005 0.0000 54 0.0005 0.0000 55 0.0005 0.0000 56 0.0005 0.0000 57 0.0005 0.0000 58 0.0005 0.0000 59 0.0005 0.0000 60 0.0004 0.0000 61 0.0003 0.0000 18005-B-wwhm 3/9/2019 6:34:12 AM Page 27 A-28 18005-B-wwhm 3/9/2019 6:34:12 AM Page 28 A-29 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0004 2353 0 0 Pass 0.0004 1338 0 0 Pass 0.0005 445 0 0 Pass 0.0005 112 0 0 Pass 0.0006 103 0 0 Pass 0.0007 89 0 0 Pass 0.0007 77 0 0 Pass 0.0008 66 0 0 Pass 0.0008 61 0 0 Pass 0.0009 58 0 0 Pass 0.0010 54 0 0 Pass 0.0010 50 0 0 Pass 0.0011 49 0 0 Pass 0.0011 47 0 0 Pass 0.0012 43 0 0 Pass 0.0013 40 0 0 Pass 0.0013 36 0 0 Pass 0.0014 36 0 0 Pass 0.0015 32 0 0 Pass 0.0015 31 0 0 Pass 0.0016 31 0 0 Pass 0.0016 29 0 0 Pass 0.0017 29 0 0 Pass 0.0018 27 0 0 Pass 0.0018 26 0 0 Pass 0.0019 26 0 0 Pass 0.0019 26 0 0 Pass 0.0020 25 0 0 Pass 0.0021 23 0 0 Pass 0.0021 23 0 0 Pass 0.0022 23 0 0 Pass 0.0022 23 0 0 Pass 0.0023 23 0 0 Pass 0.0024 21 0 0 Pass 0.0024 19 0 0 Pass 0.0025 18 0 0 Pass 0.0026 17 0 0 Pass 0.0026 16 0 0 Pass 0.0027 16 0 0 Pass 0.0027 15 0 0 Pass 0.0028 15 0 0 Pass 0.0029 14 0 0 Pass 0.0029 13 0 0 Pass 0.0030 13 0 0 Pass 0.0030 13 0 0 Pass 0.0031 13 0 0 Pass 0.0032 13 0 0 Pass 0.0032 13 0 0 Pass 0.0033 13 0 0 Pass 0.0033 13 0 0 Pass 0.0034 13 0 0 Pass 0.0035 11 0 0 Pass 0.0035 11 0 0 Pass 18005-B-wwhm 3/9/2019 6:34:12 AM Page 29 A-30 0.0036 11 0 0 Pass 0.0036 11 0 0 Pass 0.0037 11 0 0 Pass 0.0038 11 0 0 Pass 0.0038 11 0 0 Pass 0.0039 11 0 0 Pass 0.0040 11 0 0 Pass 0.0040 11 0 0 Pass 0.0041 11 0 0 Pass 0.0041 11 0 0 Pass 0.0042 11 0 0 Pass 0.0043 10 0 0 Pass 0.0043 10 0 0 Pass 0.0044 9 0 0 Pass 0.0044 9 0 0 Pass 0.0045 8 0 0 Pass 0.0046 8 0 0 Pass 0.0046 8 0 0 Pass 0.0047 8 0 0 Pass 0.0047 8 0 0 Pass 0.0048 8 0 0 Pass 0.0049 8 0 0 Pass 0.0049 8 0 0 Pass 0.0050 8 0 0 Pass 0.0050 8 0 0 Pass 0.0051 8 0 0 Pass 0.0052 8 0 0 Pass 0.0052 8 0 0 Pass 0.0053 8 0 0 Pass 0.0054 8 0 0 Pass 0.0054 7 0 0 Pass 0.0055 7 0 0 Pass 0.0055 7 0 0 Pass 0.0056 7 0 0 Pass 0.0057 6 0 0 Pass 0.0057 6 0 0 Pass 0.0058 6 0 0 Pass 0.0058 6 0 0 Pass 0.0059 6 0 0 Pass 0.0060 6 0 0 Pass 0.0060 6 0 0 Pass 0.0061 6 0 0 Pass 0.0061 6 0 0 Pass 0.0062 6 0 0 Pass 0.0063 6 0 0 Pass 0.0063 5 0 0 Pass 0.0064 5 0 0 Pass 18005-B-wwhm 3/9/2019 6:34:12 AM Page 30 A-31 Water Quality Water Quality BMP Flow and Volume for POC #2 On-line facility volume: 0.3061 acre-feet On-line facility target flow: 0.4605 cfs. Adjusted for 15 min: 0.4605 cfs. Off-line facility target flow: 0.2604 cfs. Adjusted for 15 min: 0.2604 cfs. 18005-B-wwhm 3/9/2019 6:34:12 AM Page 31 A-32 LID Report 18005-B-wwhm 3/9/2019 6:34:12 AM Page 32 A-33 POC 3 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #3 Total Pervious Area: 1.83 Total Impervious Area: 0 Mitigated Landuse Totals for POC #3 Total Pervious Area: 0.24 Total Impervious Area: 1.59 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #3 Return Period Flow(cfs) 2 year 0.0021 5 year 0.004556 10 year 0.007308 25 year 0.012763 50 year 0.01886 100 year 0.027357 Flow Frequency Return Periods for Mitigated. POC #3 Return Period Flow(cfs) 2 year 0.876721 5 year 1.196789 10 year 1.432454 25 year 1.758376 50 year 2.022372 100 year 2.305191 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #3 Year Predeveloped Mitigated 1949 0.001 0.964 1950 0.004 1.040 1951 0.003 1.050 1952 0.001 0.826 1953 0.001 1.072 1954 0.010 1.374 1955 0.008 1.043 1956 0.001 0.458 1957 0.001 0.794 1958 0.001 2.060 1959 0.003 0.792 18005-B-wwhm 3/9/2019 6:34:12 AM Page 33 A-34 1960 0.003 0.818 1961 0.007 2.660 1962 0.001 0.972 1963 0.001 1.132 1964 0.005 0.604 1965 0.001 0.739 1966 0.001 0.753 1967 0.003 1.658 1968 0.001 0.904 1969 0.001 1.846 1970 0.001 0.687 1971 0.007 0.971 1972 0.001 1.257 1973 0.001 1.017 1974 0.004 1.250 1975 0.001 0.984 1976 0.003 0.674 1977 0.001 0.676 1978 0.001 0.496 1979 0.003 1.147 1980 0.001 0.739 1981 0.001 0.685 1982 0.002 0.689 1983 0.001 0.947 1984 0.001 0.853 1985 0.002 1.181 1986 0.013 1.161 1987 0.008 1.024 1988 0.001 0.824 1989 0.001 0.845 1990 0.001 0.658 1991 0.001 0.814 1992 0.001 0.819 1993 0.001 0.632 1994 0.001 0.715 1995 0.002 0.606 1996 0.017 0.982 1997 0.045 1.016 1998 0.001 1.138 1999 0.001 0.495 2000 0.003 1.815 2001 0.001 0.593 2002 0.001 0.576 2003 0.001 0.787 2004 0.001 1.549 2005 0.001 0.710 2006 0.049 0.895 2007 0.001 0.887 2008 0.002 0.705 2009 0.001 0.713 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #3 Rank Predeveloped Mitigated 1 0.0487 2.6596 2 0.0453 2.0597 3 0.0165 1.8463 4 0.0129 1.8147 18005-B-wwhm 3/9/2019 6:34:45 AM Page 34 A-35 5 0.0101 1.6585 6 0.0084 1.5493 7 0.0076 1.3740 8 0.0071 1.2568 9 0.0069 1.2500 10 0.0048 1.1811 11 0.0043 1.1613 12 0.0038 1.1468 13 0.0033 1.1376 14 0.0033 1.1321 15 0.0030 1.0723 16 0.0029 1.0503 17 0.0029 1.0432 18 0.0027 1.0398 19 0.0027 1.0241 20 0.0025 1.0170 21 0.0022 1.0164 22 0.0022 0.9843 23 0.0017 0.9820 24 0.0015 0.9720 25 0.0015 0.9714 26 0.0015 0.9642 27 0.0015 0.9467 28 0.0015 0.9042 29 0.0015 0.8945 30 0.0015 0.8873 31 0.0015 0.8529 32 0.0015 0.8452 33 0.0015 0.8262 34 0.0015 0.8244 35 0.0015 0.8190 36 0.0015 0.8177 37 0.0015 0.8135 38 0.0015 0.7943 39 0.0015 0.7918 40 0.0015 0.7869 41 0.0015 0.7529 42 0.0015 0.7394 43 0.0015 0.7390 44 0.0015 0.7146 45 0.0015 0.7135 46 0.0015 0.7101 47 0.0015 0.7050 48 0.0014 0.6894 49 0.0014 0.6870 50 0.0014 0.6849 51 0.0014 0.6764 52 0.0014 0.6742 53 0.0014 0.6582 54 0.0014 0.6322 55 0.0014 0.6061 56 0.0014 0.6035 57 0.0014 0.5934 58 0.0014 0.5757 59 0.0014 0.4956 60 0.0013 0.4952 61 0.0010 0.4582 18005-B-wwhm 3/9/2019 6:34:45 AM Page 35 A-36 18005-B-wwhm 3/9/2019 6:34:45 AM Page 36 A-37 Duration Flows Flow(cfs) Predev Mit Percentage Pass/Fail 0.0011 2357 629900 26724 Fail 0.0012 1330 593325 44610 Fail 0.0014 437 561028 128381 Fail 0.0016 112 534078 476855 Fail 0.0018 103 510765 495888 Fail 0.0019 89 490445 551061 Fail 0.0021 77 472265 613331 Fail 0.0023 66 456009 690922 Fail 0.0025 61 441465 723713 Fail 0.0027 58 428418 738651 Fail 0.0028 54 416440 771185 Fail 0.0030 50 405532 811064 Fail 0.0032 49 395479 807100 Fail 0.0034 47 386068 821421 Fail 0.0036 43 377512 877934 Fail 0.0037 40 369598 923995 Fail 0.0039 36 362112 1005866 Fail 0.0041 36 355268 986855 Fail 0.0043 32 348851 1090159 Fail 0.0045 31 342862 1106006 Fail 0.0046 31 337301 1088067 Fail 0.0048 29 331740 1143931 Fail 0.0050 29 326821 1126968 Fail 0.0052 27 321901 1192225 Fail 0.0054 26 317410 1220807 Fail 0.0055 26 313132 1204353 Fail 0.0057 26 308854 1187900 Fail 0.0059 25 305004 1220016 Fail 0.0061 23 301154 1309365 Fail 0.0063 23 297732 1294486 Fail 0.0064 23 294310 1279608 Fail 0.0066 23 290888 1264730 Fail 0.0068 23 287679 1250778 Fail 0.0070 21 284685 1355642 Fail 0.0072 19 281690 1482578 Fail 0.0073 18 278910 1549500 Fail 0.0075 17 276129 1624288 Fail 0.0077 16 273349 1708431 Fail 0.0079 16 270782 1692387 Fail 0.0081 15 268216 1788106 Fail 0.0082 15 265863 1772419 Fail 0.0084 14 263510 1882214 Fail 0.0086 13 261157 2008900 Fail 0.0088 13 259018 1992446 Fail 0.0090 13 256666 1974353 Fail 0.0091 13 254527 1957900 Fail 0.0093 13 252602 1943092 Fail 0.0095 13 250463 1926638 Fail 0.0097 13 248538 1911830 Fail 0.0099 13 246613 1897023 Fail 0.0100 13 244688 1882215 Fail 0.0102 11 242977 2208881 Fail 0.0104 11 241052 2191381 Fail 0.0106 11 239341 2175827 Fail 18005-B-wwhm 3/9/2019 6:34:45 AM Page 37 A-38 0.0108 11 237630 2160272 Fail 0.0109 11 235918 2144709 Fail 0.0111 11 234207 2129154 Fail 0.0113 11 232710 2115545 Fail 0.0115 11 230999 2099990 Fail 0.0117 11 229502 2086381 Fail 0.0118 11 228005 2072772 Fail 0.0120 11 226507 2059154 Fail 0.0122 11 225010 2045545 Fail 0.0124 11 223513 2031936 Fail 0.0126 10 222016 2220160 Fail 0.0127 10 220732 2207320 Fail 0.0129 9 219235 2435944 Fail 0.0131 9 217952 2421688 Fail 0.0133 8 216669 2708362 Fail 0.0135 8 215171 2689637 Fail 0.0136 8 213888 2673600 Fail 0.0138 8 212626 2657825 Fail 0.0140 8 211300 2641250 Fail 0.0142 8 209974 2624675 Fail 0.0144 8 208669 2608362 Fail 0.0145 8 207429 2592862 Fail 0.0147 8 206209 2577612 Fail 0.0149 8 205033 2562912 Fail 0.0151 8 203835 2547937 Fail 0.0153 8 202616 2532700 Fail 0.0154 8 201440 2518000 Fail 0.0156 8 200263 2503287 Fail 0.0158 8 199087 2488587 Fail 0.0160 7 197932 2827600 Fail 0.0162 7 196756 2810800 Fail 0.0163 7 195622 2794600 Fail 0.0165 7 194403 2777185 Fail 0.0167 6 193248 3220800 Fail 0.0169 6 192136 3202266 Fail 0.0171 6 191045 3184083 Fail 0.0172 6 189911 3165183 Fail 0.0174 6 188799 3146650 Fail 0.0176 6 187708 3128466 Fail 0.0178 6 186575 3109583 Fail 0.0180 6 185505 3091750 Fail 0.0181 6 184393 3073216 Fail 0.0183 6 183281 3054683 Fail 0.0185 6 182233 3037216 Fail 0.0187 5 181185 3623700 Fail 0.0189 5 180115 3602300 Fail The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. The development has an increase in flow durations for more than 50% of the flows for the range of the duration analysis. 18005-B-wwhm 3/9/2019 6:34:45 AM Page 38 A-39 Water Quality Water Quality BMP Flow and Volume for POC #3 On-line facility volume: 0.1984 acre-feet On-line facility target flow: 0.3031 cfs. Adjusted for 15 min: 0.3031 cfs. Off-line facility target flow: 0.1717 cfs. Adjusted for 15 min: 0.1717 cfs. 18005-B-wwhm 3/9/2019 6:34:45 AM Page 39 A-40 LID Report 18005-B-wwhm 3/9/2019 6:34:45 AM Page 40 A-41 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 18005-B-wwhm 3/9/2019 6:34:45 AM Page 41 A-42 Appendix Predeveloped Schematic 18005-B-wwhm 3/9/2019 6:34:45 AM Page 42 A-43 Mitigated Schematic 18005-B-wwhm 3/9/2019 6:34:46 AM Page 43 A-44 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18005-B-wwhm.wdm MESSU 25 Pre18005-B-wwhm.MES 27 Pre18005-B-wwhm.L61 28 Pre18005-B-wwhm.L62 30 POC18005-B-wwhm1.dat 32 POC18005-B-wwhm3.dat 31 POC18005-B-wwhm2.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 1 COPY 501 COPY 503 COPY 502 DISPLY 1 DISPLY 3 DISPLY 2 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 B-1 MAX 1 2 30 9 3 B-WQ MAX 1 2 32 9 2 B-2 MAX 1 2 31 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 503 1 1 502 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 A/B, Forest, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** 18005-B-wwhm 3/9/2019 6:34:46 AM Page 44 A-45 # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 1 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 1 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 1 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 1 0 5 2 400 0.05 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 1 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 1 0.2 0.5 0.35 0 0.7 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 1 0 0 0 0 3 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 45 A-46 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** B-1*** PERLND 1 2.68 COPY 501 12 PERLND 1 2.68 COPY 501 13 Basin 2*** PERLND 1 4.42 COPY 501 12 PERLND 1 4.42 COPY 501 13 B-WQ*** PERLND 1 1.83 COPY 503 12 PERLND 1 1.83 COPY 503 13 B-2*** PERLND 1 0.62 COPY 502 12 PERLND 1 0.62 COPY 502 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 COPY 503 OUTPUT MEAN 1 1 48.4 DISPLY 3 INPUT TIMSER 1 COPY 502 OUTPUT MEAN 1 1 48.4 DISPLY 2 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 46 A-47 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1.2 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1.2 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL COPY 503 OUTPUT MEAN 1 1 48.4 WDM 503 FLOW ENGL REPL COPY 502 OUTPUT MEAN 1 1 48.4 WDM 502 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN 18005-B-wwhm 3/9/2019 6:34:46 AM Page 47 A-48 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18005-B-wwhm.wdm MESSU 25 Mit18005-B-wwhm.MES 27 Mit18005-B-wwhm.L61 28 Mit18005-B-wwhm.L62 32 POC18005-B-wwhm3.dat 30 POC18005-B-wwhm1.dat 31 POC18005-B-wwhm2.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 16 IMPLND 4 IMPLND 8 IMPLND 11 RCHRES 1 RCHRES 2 COPY 503 COPY 1 COPY 501 COPY 2 COPY 502 DISPLY 3 DISPLY 1 DISPLY 2 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 3 WQ MAX 1 2 32 9 1 StormTech A MAX 1 2 30 9 2 StormTech-B MAX 1 2 31 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 503 1 1 501 1 1 2 1 1 502 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** 18005-B-wwhm 3/9/2019 6:34:46 AM Page 48 A-49 # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 16 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 16 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 16 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 16 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 4 ROOF TOPS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 11 PARKING/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 4 0 0 1 0 0 0 8 0 0 1 0 0 0 11 0 0 1 0 0 0 END ACTIVITY PRINT-INFO 18005-B-wwhm 3/9/2019 6:34:46 AM Page 49 A-50 <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 4 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 11 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 4 0 0 0 0 0 8 0 0 0 0 0 11 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 4 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 11 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 4 0 0 8 0 0 11 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 4 0 0 8 0 0 11 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin A*** PERLND 16 0.24 RCHRES 1 2 PERLND 16 0.24 RCHRES 1 3 IMPLND 4 0.85 RCHRES 1 5 IMPLND 8 0.07 RCHRES 1 5 IMPLND 11 1.52 RCHRES 1 5 Basin B*** IMPLND 4 0.62 RCHRES 2 5 WQ*** PERLND 16 0.24 COPY 503 12 PERLND 16 0.24 COPY 503 13 IMPLND 8 0.07 COPY 503 15 IMPLND 11 1.52 COPY 503 15 ******Routing****** PERLND 16 0.24 COPY 1 12 IMPLND 4 0.85 COPY 1 15 IMPLND 8 0.07 COPY 1 15 IMPLND 11 1.52 COPY 1 15 PERLND 16 0.24 COPY 1 13 IMPLND 4 0.62 COPY 2 15 RCHRES 1 1 COPY 501 17 RCHRES 2 1 COPY 502 17 END SCHEMATIC NETWORK 18005-B-wwhm 3/9/2019 6:34:46 AM Page 50 A-51 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 503 OUTPUT MEAN 1 1 48.4 DISPLY 3 INPUT TIMSER 1 COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 COPY 502 OUTPUT MEAN 1 1 48.4 DISPLY 2 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** 1 StormTech A 2 1 1 1 28 0 1 2 StormTech-B 2 1 1 1 28 0 1 END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9 2 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 2 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.02 0.0 3.0 0.5 0.0 2 2 0.01 0.0 3.0 0.5 0.0 END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 1 66 5 Depth Area Volume Outflow1 Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.048304 0.000000 0.000000 0.000000 0.083333 0.048304 0.001610 0.000000 0.666312 18005-B-wwhm 3/9/2019 6:34:46 AM Page 51 A-52 0.166667 0.048304 0.003220 0.000000 0.666312 0.250000 0.048304 0.004830 0.000000 0.666312 0.333333 0.048304 0.006441 0.000000 0.666312 0.416667 0.048304 0.008050 0.000000 0.666312 0.500000 0.048304 0.009661 0.000000 0.666312 0.583333 0.048304 0.011271 0.000000 0.666312 0.666667 0.048304 0.012880 0.000000 0.666312 0.750000 0.048304 0.014491 0.000000 0.666312 0.833333 0.048304 0.018033 0.000000 0.666312 0.916667 0.048304 0.021558 0.000000 0.666312 1.000000 0.048304 0.025071 0.000000 0.666312 1.083333 0.048304 0.028572 0.000000 0.666312 1.166667 0.048304 0.032061 0.000000 0.666312 1.250000 0.048304 0.035534 0.000000 0.666312 1.333333 0.048304 0.039002 0.000000 0.666312 1.416667 0.048304 0.042449 0.000000 0.666312 1.500000 0.048304 0.045884 0.000000 0.666312 1.583333 0.048304 0.049302 0.000000 0.666312 1.666667 0.048304 0.052705 0.000000 0.666312 1.750000 0.048304 0.056091 0.000000 0.666312 1.833333 0.048304 0.059458 0.000000 0.666312 1.916667 0.048304 0.062807 0.000000 0.666312 2.000000 0.048304 0.066136 0.000000 0.666312 2.083333 0.048304 0.069445 0.000000 0.666312 2.166667 0.048304 0.072731 0.000000 0.666312 2.250000 0.048304 0.075994 0.000000 0.666312 2.333333 0.048304 0.079233 0.000000 0.666312 2.416667 0.048304 0.082447 0.000000 0.666312 2.500000 0.048304 0.085633 0.000000 0.666312 2.583333 0.048304 0.088792 0.000000 0.666312 2.666667 0.048304 0.091920 0.000000 0.666312 2.750000 0.048304 0.095018 0.000000 0.666312 2.833333 0.048304 0.098082 0.000000 0.666312 2.916667 0.048304 0.101112 0.000000 0.666312 3.000000 0.048304 0.104106 0.000000 0.666312 3.083333 0.048304 0.107058 0.000000 0.666312 3.166667 0.048304 0.109974 0.000000 0.666312 3.250000 0.048304 0.112847 0.000000 0.666312 3.333333 0.048304 0.115674 0.000000 0.666312 3.416667 0.048304 0.118446 0.000000 0.666312 3.500000 0.048304 0.121172 0.000000 0.666312 3.583333 0.048304 0.123842 0.000000 0.666312 3.666667 0.048304 0.126451 0.000000 0.666312 3.750000 0.048304 0.128987 0.000000 0.666312 3.833333 0.048304 0.131455 0.000000 0.666312 3.916667 0.048304 0.133842 0.000000 0.666312 4.000000 0.048304 0.136133 0.000000 0.666312 4.083333 0.048304 0.138299 0.000000 0.666312 4.166667 0.048304 0.140285 0.000000 0.666312 4.250000 0.048304 0.142118 0.000000 0.666312 4.333333 0.048304 0.143888 0.000000 0.666312 4.416667 0.048304 0.145605 0.000000 0.666312 4.500000 0.048304 0.147247 0.000000 0.666312 4.583333 0.048304 0.148934 0.000000 0.666312 4.666667 0.048304 0.150544 0.000000 0.666312 4.750000 0.048304 0.152155 0.000000 0.666312 4.833333 0.048304 0.153764 0.000000 0.666312 4.916667 0.048304 0.155375 0.000000 0.666312 5.000000 0.048304 0.156985 0.000000 0.666312 5.083333 0.048304 0.158594 0.000000 0.666312 5.166667 0.048304 0.160205 0.000000 0.666312 5.250000 0.048304 0.161815 0.000000 0.666312 5.333333 0.048304 0.163425 0.000000 0.666312 5.416667 0.048304 0.165035 0.000000 0.666312 END FTABLE 1 FTABLE 2 66 5 Depth Area Volume Outflow1 Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.015696 0.000000 0.000000 0.000000 18005-B-wwhm 3/9/2019 6:34:46 AM Page 52 A-53 0.083333 0.015696 0.000523 0.000000 0.266000 0.166667 0.015696 0.001046 0.000000 0.266000 0.250000 0.015696 0.001569 0.000000 0.266000 0.333333 0.015696 0.002093 0.000000 0.266000 0.416667 0.015696 0.002616 0.000000 0.266000 0.500000 0.015696 0.003139 0.000000 0.266000 0.583333 0.015696 0.003662 0.000000 0.266000 0.666667 0.015696 0.004185 0.000000 0.266000 0.750000 0.015696 0.004709 0.000000 0.266000 0.833333 0.015696 0.005844 0.000000 0.266000 0.916667 0.015696 0.006973 0.000000 0.266000 1.000000 0.015696 0.008097 0.000000 0.266000 1.083333 0.015696 0.009219 0.000000 0.266000 1.166667 0.015696 0.010336 0.000000 0.266000 1.250000 0.015696 0.011447 0.000000 0.266000 1.333333 0.015696 0.012559 0.000000 0.266000 1.416667 0.015696 0.013662 0.000000 0.266000 1.500000 0.015696 0.014762 0.000000 0.266000 1.583333 0.015696 0.015856 0.000000 0.266000 1.666667 0.015696 0.016945 0.000000 0.266000 1.750000 0.015696 0.018029 0.000000 0.266000 1.833333 0.015696 0.019107 0.000000 0.266000 1.916667 0.015696 0.020179 0.000000 0.266000 2.000000 0.015696 0.021244 0.000000 0.266000 2.083333 0.015696 0.022303 0.000000 0.266000 2.166667 0.015696 0.023355 0.000000 0.266000 2.250000 0.015696 0.024399 0.000000 0.266000 2.333333 0.015696 0.025435 0.000000 0.266000 2.416667 0.015696 0.026464 0.000000 0.266000 2.500000 0.015696 0.027484 0.000000 0.266000 2.583333 0.015696 0.028494 0.000000 0.266000 2.666667 0.015696 0.029495 0.000000 0.266000 2.750000 0.015696 0.030486 0.000000 0.266000 2.833333 0.015696 0.031467 0.000000 0.266000 2.916667 0.015696 0.032436 0.000000 0.266000 3.000000 0.015696 0.033394 0.000000 0.266000 3.083333 0.015696 0.034338 0.000000 0.266000 3.166667 0.015696 0.035272 0.000000 0.266000 3.250000 0.015696 0.036192 0.000000 0.266000 3.333333 0.015696 0.037098 0.000000 0.266000 3.416667 0.015696 0.037984 0.000000 0.266000 3.500000 0.015696 0.038858 0.000000 0.266000 3.583333 0.015696 0.039713 0.000000 0.266000 3.666667 0.015696 0.040550 0.000000 0.266000 3.750000 0.015696 0.041361 0.000000 0.266000 3.833333 0.015696 0.042153 0.000000 0.266000 3.916667 0.015696 0.042919 0.000000 0.266000 4.000000 0.015696 0.043656 0.000000 0.266000 4.083333 0.015696 0.044351 0.000000 0.266000 4.166667 0.015696 0.044993 0.000000 0.266000 4.250000 0.015696 0.045586 0.000000 0.266000 4.333333 0.015696 0.046160 0.000000 0.266000 4.416667 0.015696 0.046716 0.000000 0.266000 4.500000 0.015696 0.047249 0.000000 0.266000 4.583333 0.015696 0.047824 0.000000 0.266000 4.666667 0.015696 0.048347 0.000000 0.266000 4.750000 0.015696 0.048871 0.000000 0.266000 4.833333 0.015696 0.049393 0.000000 0.266000 4.916667 0.015696 0.049917 0.000000 0.266000 5.000000 0.015696 0.050440 0.000000 0.266000 5.083333 0.015696 0.050963 0.000000 0.266000 5.166667 0.015696 0.051486 0.000000 0.266000 5.250000 0.015696 0.052009 0.000000 0.266000 5.333333 0.015696 0.052533 0.000000 0.266000 5.416667 0.015696 0.053056 0.000000 0.266000 END FTABLE 2 END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** 18005-B-wwhm 3/9/2019 6:34:46 AM Page 53 A-54 <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1.2 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1.2 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1008 FLOW ENGL REPL RCHRES 1 HYDR O 1 1 1 WDM 1009 FLOW ENGL REPL RCHRES 1 HYDR O 2 1 1 WDM 1010 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1011 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL COPY 3 OUTPUT MEAN 1 1 48.4 WDM 703 FLOW ENGL REPL COPY 503 OUTPUT MEAN 1 1 48.4 WDM 803 FLOW ENGL REPL RCHRES 2 HYDR RO 1 1 1 WDM 1012 FLOW ENGL REPL RCHRES 2 HYDR O 1 1 1 WDM 1013 FLOW ENGL REPL RCHRES 2 HYDR O 2 1 1 WDM 1014 FLOW ENGL REPL RCHRES 2 HYDR STAGE 1 1 1 WDM 1015 STAG ENGL REPL COPY 2 OUTPUT MEAN 1 1 48.4 WDM 702 FLOW ENGL REPL COPY 502 OUTPUT MEAN 1 1 48.4 WDM 802 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2 MASS-LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3 MASS-LINK 5 IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5 MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 MASS-LINK 17 RCHRES OFLOW OVOL 1 COPY INPUT MEAN END MASS-LINK 17 END MASS-LINK END RUN 18005-B-wwhm 3/9/2019 6:34:46 AM Page 54 A-55 Predeveloped HSPF Message File 18005-B-wwhm 3/9/2019 6:34:46 AM Page 55 A-56 Mitigated HSPF Message File ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 10:30 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7118.8 7188.9 7205.6 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 10:30 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -5.209E+03 1.2379 1.2379E+00 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 10:45 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7531.2 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 10:45 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -2.475E+04 5.8802 5.8801E+00 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11: 0 RCHRES: 1 18005-B-wwhm 3/9/2019 6:34:46 AM Page 56 A-57 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8012.9 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11: 0 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -5.365E+04 12.749 1.2749E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11:15 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8312.5 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11:15 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -7.163E+04 17.021 1.7021E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11:30 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8488.2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 57 A-58 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11:30 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -8.217E+04 19.527 1.9527E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11:45 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8344.7 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11:45 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -7.356E+04 17.480 1.7480E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12: 0 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8222.9 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12: 0 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). 18005-B-wwhm 3/9/2019 6:34:46 AM Page 58 A-59 Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -6.625E+04 15.743 1.5743E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12:15 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7975.0 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12:15 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -5.138E+04 12.208 1.2208E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12:30 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7621.2 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12:30 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -3.015E+04 7.1645 7.1645E+00 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12:45 18005-B-wwhm 3/9/2019 6:34:46 AM Page 59 A-60 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7199.7 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12:45 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -4.857E+03 1.1541 1.1541E+00 2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 60 A-61 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright Â© by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com 18005-B-wwhm 3/9/2019 6:34:46 AM Page 61 A-62 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX B â€“ INFILTRATION STUDY AND GEOTECHNICAL REPORT B-1 SONDERGAARD GEOSCIENCE, PLLC 13012 65TH Avenue SE Snohomish, Washington 98296 April 24, 2018 Project No. J-0045 Gayteway LLC P.O. Box 1727 Bellevue, WA 98009 Attention: Chris Gayte Subject: Soil Infiltration Rate Building B and C Gayteway Business Park 20015 67th Avenue NE Arlington, Washington Dear Mr. Gayte: As requested, Sondergaard Geosciences, PLLC (SGP) is pleased to present our recommendations for soil infiltration rate for the subject site. This study has been prepared for the exclusive use of Gayteway LLC and their agents, for specific application to this project. Within the limitations of scope and schedule, our services have been performed in accordance with generally accepted engineering geology practices in effect in this area at the time our study was prepared. No other warranty, express or implied, is made. SITE AND PROJECT DESCRIPTION The subject property consists of an irregularly-shaped parcel (Snohomish County Parcel Number 31051400200700), with a combined area of approximately 54 acres located at 20015 67th Avenue NE in Arlington, Washington (Figure 1). The subject property is bounded to the east, south and north by commercial/industrial development and to the west by 67th Avenue NE. The proposed project that is the subject of this report is located on the northwest portion of the property fronting 67th Avenue NE. At the project site, overall site topography is relative flat. The subject site formerly was occupied by a lumber mill that has since be demolished. The project site is clear of vegetation Based on our discussions with you, we understand that plans for the current project include the construction of two concrete tilt-up structures; one totaling approximately 65,950 square feet (Building B) and one totaling approximately 66,100 square feet( Building C). April 24, 2018 SONDERGARRD GEOSCIENCES, PLLC 1 B-2 Gayteway Business Park Buildings B and C Soil Infiltration Rate Arlington, Washington SUBSURFACE EXPLORATION Twelve exploration pits were completed at the site by SGP on January 22, 2018. The exploration pits were continuously observed and logged by an engineering geologist. Descriptions of the soils encountered at the site are provided below. Fill Crushed Rock Fill Fill consisting of loose to medium dense, moist, tan crushed rock (1/2-minus) was encountered in exploration pits EP-5 and EP-6. The crushed rock fill was generally found at the surface to depths of approximately 1 to 4 feet at these locations. This material is suitable for reuse as structural fill if properly compacted. Wood Fill Fill typically consisting of loose, moist, dark brown, sand with wood fragments and soft, moist dark brown woodchips, dimensional lumber and small logs was encountered in exploration pits EP-1, EP-2, EP-3, EP-4, EP-5, EP-6 and EP-11. The wood fill was typically found at the surface to depths ranging from approximately 2 to 8 feet. Wood fill was also encountered in the recent soil sampling excavation I-6 from just below the pavement to a depth of approximately 6 feet. Six to eight-inch diameter logs were encountered in soil sampling excavation I-3 at a depth of about 4 feet. Recessional Outwash Recessional outwash soils were encountered underlying the fills to the full depths explored depths of approximately 9 to 14 feet below the existing ground surface. This soil generally consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. Ground Water Ground water seepage was not encountered in the exploration pits advanced for this report in January 2018 with the exception of exploration EP-9. Exploration pit EP-9 exhibited slow ground water seepage at a depth of about 6.5 feet. It should be noted that the depth and occurrence of ground water seepage at the site likely varies in response to such factors as changes in season, amount of precipitation, location, and site use. SGP returned to the site on to collect soil samples for grain size analyses at six planned infiltration locations and depths (Figure 1) identified by the project civil engineer. Ground April 24, 2018 SONDERGARRD GEOSCIENCES, PLLC 2 B-3 Gayteway Business Park Buildings B and C Soil Infiltration Rate Arlington, Washington water was not encountered at the time of excavation in April 2018 at sample locations I-1, I-2, I- 4 and I-5. Slow to moderate ground water seepage was observed at sample location I-3 at a depth of about 4 feet and I-6 at a depth of about 8 feet. At the depths specified, all infiltration would be into the granular recessional outwash deposits. Infiltration We understand that the on-site infiltration of site generated storm water is the preferred method for the disposal of storm water. Because the soils underlying the site consist of unconsolidated recessional outwash, the methods outlined in the January 2016 Snohomish County Drainage Manual, Volume III, Section 3.3.6 Soil Grain Size Analysis Method were used to determine the soil infiltration rate. The recommended uncorrected infiltration rates based upon grain size analyses of soil samples collected at each proposed infiltration location and performed in accordance with ASTM Method D422 are presented in Table 1 below: Table 1. Soil Infiltration Rate Sample No. Depth (ft) Ksat (cm/sec) Uncorrected Infiltration Rate (in/hr) I-1 9 6.91 x 10-2 98 I-2 7 2.67 x 10-2 38 I-3 7 9.4 x 10-2 133 I-4 9 6.53 x 10-2 93 I-5 9 4.0 x 10-1 568 I-6 7 4.29 x 10-2 61 Excluding location I-5 and averaging the results from the remaining five locations results in an average uncorrected soil infiltration rate of 85 inches per hour. The infiltration rates presented above are uncorrected and do not contain factors of safety. April 24, 2018 SONDERGARRD GEOSCIENCES, PLLC 3 B-4 B-5 SITE AREA 408,000 SF (9.36 ACRES) BUILDING AREA 105,000 SF BUILDING B 17 100 SF BUILDING C --n 122,100 SF TOTAL I-6 1 PARKING: â–¡111111111111111 PARKING LOT A ï¿½ 180 STALLS PROVIDED PARKING LOT A -----+-1==------ BUILDING B 011111111111111 ï¿½ 115 STALLS PROVIDED 180 STALLS BUILDING C â–¡1111111111111ï¿½ 63 STALLS PROVIDED TOTAL SITE 358 TOTAL STALLS PROVIDED 01111111111110 I-3 7 175'-0" J I 1 i I J I-5 I-5 Sample Number and I Approximate Location 1 'b i ï¿½ I ï¿½ J BUILDING B 105,000 SF I 1 'b i I I 0 0 c.o w z w ::::> z I-2 ï¿½ I-4 7 b J I 0 76'-5" 180'-0" 'b I-1 BUILDING C I 17,100 SF rn o 111111111n111111110 NORTH INFILTRATION SOIL SAMPLE LOCATIONS GAYTEWAY BUSINESS PARK ARLINGTON, WASHINGTON $ 1' = 100' J-0045 FIGURE 1 GA YTEWAY BUSINESS PARK - SITE PLAN cï¿½ ARLINGTON, WASHINGTON GA YTEW A Y LLC. a r C h I t e C t s 04/04/18 B-6 Particle Size Distribution Report 6 in. 3 in. 2 in.1Â½ in.1 in.Â¾ in.Â½ in.3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 0.0 0.6 1.6 63.9 32.1 1.8 TEST RESULTS Material Description Opening Percent Spec.* Pass? SAND, trace silt, trace sand Size Finer (Percent) (X=Fail) 1.5 100.0 1 100.0 Atterberg Limits (ASTM D 4318) .75 100.0 PL= NP LL= NV PI= NP .375 100.0 #4 99.4 Classification USCS (D 2487)= SP AASHTO (M 145)= A-1-b #8 98.3 #10 97.8 Coefficients #20 86.1 D90= 1.0305 D85= 0.8336 D60= 0.5925 #40 33.9 D50= 0.5254 D30= 0.3998 D15= 0.2863 #60 11.2 D10= 0.2377 Cu= 2.49 Cc= 1.14 #100 3.5 #200 1.8 Remarks #270 1.6 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: Bn Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-1 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-7 Particle Size Distribution Report 6 in. 3 in. 2 in.1Â½ in.1 in.Â¾ in.Â½ in.3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 12.6 23.4 10.4 27.0 20.8 5.8 TEST RESULTS Material Description Opening Percent Spec.* Pass? very gravelly, SAND, some silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 94.1 Atterberg Limits (ASTM D 4318) .75 87.4 PL= Np LL= NV PI= .375 74.4 #4 64.0 Classification USCS (D 2487)= SP-SM AASHTO (M 145)= A-1-b #8 55.3 #10 53.6 Coefficients #20 43.2 D90= 21.2237 D85= 17.1115 D60= 3.5036 #40 26.6 D50= 1.3947 D30= 0.4838 D15= 0.2545 #60 14.7 D10= 0.1705 Cu= 20.55 Cc= 0.39 #100 9.0 #200 5.8 Remarks #270 5.0 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-2 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-8 Particle Size Distribution Report 6 in. 3 in. 2 in.1Â½ in.1 in.Â¾ in.Â½ in.3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 19.2 35.5 13.3 22.2 7.6 2.2 TEST RESULTS Material Description Opening Percent Spec.* Pass? very sandy, GRAVEL, trace silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 86.1 Atterberg Limits (ASTM D 4318) .75 80.8 PL= NP LL= NV PI= NP .375 59.4 #4 45.3 Classification USCS (D 2487)= GP AASHTO (M 145)= A-1-a #8 34.4 #10 32.0 Coefficients #20 20.5 D90= 29.1512 D85= 24.0878 D60= 9.7280 #40 9.8 D50= 6.3283 D30= 1.7297 D15= 0.6026 #60 4.8 D10= 0.4327 Cu= 22.48 Cc= 0.71 #100 3.0 #200 2.2 Remarks #270 2.1 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-3 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-9 Particle Size Distribution Report 6 in. 3 in. 2 in.1Â½ in.1 in.Â¾ in.Â½ in.3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 16.1 20.9 12.9 38.7 8.7 2.7 TEST RESULTS Material Description Opening Percent Spec.* Pass? very gravelly, SAND, trace silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 90.0 Atterberg Limits (ASTM D 4318) .75 83.9 PL= NP LL= NV PI= .375 73.2 #4 63.0 Classification USCS (D 2487)= SP AASHTO (M 145)= A-1-a #8 52.9 #10 50.1 Coefficients #20 22.2 D90= 25.4438 D85= 20.1425 D60= 3.8522 #40 11.4 D50= 1.9933 D30= 1.0813 D15= 0.5849 #60 5.9 D10= 0.3757 Cu= 10.25 Cc= 0.81 #100 3.6 #200 2.7 Remarks #270 2.6 Collected: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-4 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-10 Particle Size Distribution Report 6 in. 3 in. 2 in.1Â½ in.1 in.Â¾ in.Â½ in.3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 37.5 27.0 12.9 17.0 4.0 1.6 TEST RESULTS Material Description Opening Percent Spec.* Pass? very sandy, GRAVEL, trace silt Size Finer (Percent) (X=Fail) 2 100.0 1.5 96.2 Atterberg Limits (ASTM D 4318) 1 73.7 PL= NP LL= NV PI= .75 62.5 .375 47.5 Classification USCS (D 2487)= GP AASHTO (M 145)= A-1-a #4 35.5 #8 24.9 Coefficients #10 22.6 D90= 33.3680 D85= 30.6805 D60= 17.4510 #20 11.7 D50= 10.9814 D30= 3.3420 D15= 1.1264 #40 5.6 D10= 0.7254 Cu= 24.06 Cc= 0.88 #60 3.3 #100 2.2 Remarks #200 1.6 Collected by: Jon Sondergaard #270 1.4 Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-5 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-11 Particle Size Distribution Report 6 in. 3 in. 2 in.1Â½ in.1 in.Â¾ in.Â½ in.3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 1.0 30.3 15.9 32.9 13.6 6.3 TEST RESULTS Material Description Opening Percent Spec.* Pass? very gravelly, SAND, some silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 100.0 Atterberg Limits (ASTM D 4318) .75 99.0 PL= NP LL= NV PI= .375 89.2 #4 68.7 Classification USCS (D 2487)= SP-SM AASHTO (M 145)= A-1-b #8 55.7 #10 52.8 Coefficients #20 36.9 D90= 9.8529 D85= 8.1746 D60= 3.0792 #40 19.9 D50= 1.6952 D30= 0.6420 D15= 0.3287 #60 11.3 D10= 0.2187 Cu= 14.08 Cc= 0.61 #100 7.7 #200 6.3 Remarks #270 6.1 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-6 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-12 SONDERGAARD GEOSCIENCE, PLLC 13012 65TH Avenue SE Snohomish, Washington 98296 February 9, 2018 Project No. J-0045 Gayteway LLC P.O. Box 1727 Bellevue, WA 98009 Attention: Chris Gayte Subject: Geotechnical Engineering Study Building B and C Gayteway Business Park 20015 67th Avenue NE Arlington, Washington Dear Mr. Gayte: As requested, Sondergaard Geosciences, PLLC (SGP) is pleased to present our geotechnical engineering study for the subject site. This study has been prepared for the exclusive use of Gayteway LLC and their agents, for specific application to this project. Within the limitations of scope and schedule, our services have been performed in accordance with generally accepted engineering geology and geotechnical engineering practices in effect in this area at the time our study was prepared. No other warranty, express or implied, is made. SITE AND PROJECT DESCRIPTION The subject property consists of an irregularly-shaped parcel (Snohomish County Parcel Number 31051400200700), with a combined area of approximately 54 acres located at 20015 67th Avenue NE in Arlington, Washington (Figure 1). The subject property is bounded to the east, south and north by commercial/industrial development and to the west by 67th Avenue NE. The proposed project that is the subject of this report is located on the northwest portion of the property fronting 67th Avenue NE. At the project site, overall site topography is relative flat. The subject site formerly was occupied by a lumber mill that has since be demolished. The project site is clear of vegetation Based on our discussions with you, we understand that current plans for the current project include the construction of two concrete tilt-up structures; one totaling approximately 65,950 square feet (Building B) and one totaling approximately 66,100 square feet. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 1 B-13 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington SUBSURFACE EXPLORATION Twelve exploration pits were completed at the site by SGP on January 22, 2018. The approximate locations of the explorations are shown on the attached Site Plan Figure 2. The exploration pits were completed on the property using an excavator provided by the owner and were continuously observed and logged by an engineering geologist. Logs of the exploration pits are attached to this report. Descriptions of the soils encountered at the site are provided below. Fill Crushed Rock Fill Fill consisting of loose to medium dense, moist, tan crushed rock (1/2-minus) was encountered in exploration pits EP-5 and EP-6. The crushed rock fill was generally found at the surface to depths of approximately 1 to 4 feet at these locations. This material is suitable for reuse as structural fill if properly compacted. Wood Fill Fill typically consisting of loose, moist, dark brown, sand with wood fragments and soft, moist dark brown woodchips, dimensional lumber and small logs was encountered in exploration pits EP-1, EP-2, EP-3, EP-4, EP-5, EP-6 and EP-11. The wood fill was typically found at the surface to depths ranging from approximately 2 to 8 feet. The approximate thickness of the wood fill is shown on Figure 2. This material is not suitable for the support of foundations, floor slabs or pavements. Recessional Outwash Recessional outwash soils were encountered underlying the fills to the full depths explored depths of approximately 9 to 12 feet below the existing ground surface. This soil generally consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. This unit is suitable for support of foundations, slabs and pavements when properly compacted as recommended in this report. Ground Water Ground water seepage was not encountered in the exploration pits advanced for this report in January 2018 with the exception of exploration EP-9. Exploration pit EP-9 exhibited slow ground water seepage at a depth of about 6.5 feet. It should be noted that the depth and February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 2 B-14 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington occurrence of ground water seepage at the site likely varies in response to such factors as changes in season, amount of precipitation, location, and site use. GEOLOLGIC HAZARDS The following discussion of applicable geologic hazards is based on review of the City of Arlington Municipal Code (AMC) and the geologic, topographic, and ground and surface water conditions as observed and discussed herein. The discussion will be limited to landslide and steep slope hazards, seismic hazards, and erosion hazards. Slope Hazards and Mitigations The site is characterized by flat, generally gentle topography. In our opinion, the site does not meet the criteria of a Landslide Hazard Area according to AMC Part IV Section 20.93.600(b)(2). Seismic Hazards and Mitigations Seismic Hazard Area Ground water was not encountered in the site explorations completed to maximum depth of about 12 feet below the existing site grade. Review of well logs on file at the Washington State Department of Ecology indicates that the shallowest ground water in the vicinity of the site occurs at depths of about 30 to 50 feet below the ground surface and that soils below this depth typically consist of clay and silt. In our opinion, the subsurface conditions at the project site do not meet the definition in AMC Part IV Section 20.93.600(b)(4) for a Seismic Hazard Area due to the depth to the shallowest ground water and the density and fine-grained nature of the soils at and below that depth. However, earthquakes occur in the Puget Lowland with great regularity. The majority of these events are small and are usually not felt by people. However, large earthquakes do occur, as evidenced by the 1949, 7.2-magnitude event; the 1965, 6.5-magnitude event; and the 2001, 6.8-magnitude event. The 1949 earthquake appears to have been the largest in this area during recorded history. Evaluation of return rates indicates that an earthquake of the magnitude between 5.5 and 6.0 is likely within a given 20- to 40-year period. Generally, there are four types of potential hazards associated with large seismic events: 1) surficial ground rupture, 2) seismically induced landslides, 3) liquefaction, and 4) ground motion. The potential for each of these hazards to adversely impact the proposed project is discussed below. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 3 B-15 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington Surficial Ground Rupture The project site is located approximately 16 miles southwest of the Devilâ€™s Mountain Fault Zone. This fault systems in has been hypothesized to have a reoccurrence interval in excess of several thousand years. Due to the suspected long recurrence interval and distance from the subject site, the potential for surficial ground rupture is considered to be low during the expected life of the proposed development. No mitigation efforts beyond complying with the requirements of the local jurisdictions and the current International Building Code (IBC) are recommended for this site. Seismically Induced Landslides The potential risk of damage to the proposed structures by seismically induced land sliding is low due to the gentle topography and lack of ground water seepage on the project site, in our opinion. Liquefaction Liquefaction is the process of loose, saturated sand losing its internal shear strength when subjected to cyclic loading, as may occur during an earthquake. Due to the lack of a shallow ground water table at the site and the density and fine-grained nature of soils below the ground water at depth, the potential for liquefaction to occur is low, in our opinion. Ground Motion It is our opinion that earthquake damage to the proposed structures, when founded on suitable bearing strata in accordance with the recommendations contained herein, will likely be caused by the intensity and acceleration associated with the event. Structural design for the project should follow current IBC standards. The 2015 IBC defines Site Classification by reference to Table 20.3.-1 of the American Society of Civil Engineers publication ASCE 7, the current version of which is ASCE 7-10. In our opinion the subsurface conditions at the site are consistent with a Site Classification of â€œDâ€ as defined in the referenced documents. Erosion Hazards and Mitigations The subject property does not meet the criteria for an erosion hazard area as defined in AMC Part IV Section 20.93.600(b)(1). The following discussion addresses potential erosion hazards that could develop during construction. The most effective erosion control measure is the maintenance of adequate ground cover. Maintaining cover measures atop disturbed ground provides the greatest reduction to the February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 4 B-16 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington potential generation of turbid runoff and sediment transport. During the local wet season (October 1 through March 31), exposed soil should not remain uncovered for more than 2 days unless it is actively being worked. Ground-cover measures can include erosion control matting, plastic sheeting, straw mulch, crushed rock or recycled concrete, or mature hydroseed. Some fine-grained surface soils are the result of natural weathering processes that have broken down parent materials into their mineral components. These mineral components can have an inherent electrical charge. Electrically charged mineral fines attract oppositely charged particles and can combine (flocculate) to form larger particles that will settle out of suspension. The sediments produced during the recent glaciation of Puget Sound are, however, most commonly the suspended soils that are carried by site storm water. The fine-grained fraction of the glacially derived soil is referred to as â€œrock flour,â€ which is primarily a silt-sized particle with no electrical charge. These particles, once suspended in water, may have settling times in periods of months. Therefore, the flow length within a temporary sediment control trap or pond has virtually no effect on the water quality of the discharge, since silt will not settle out of suspension in the time it takes to flow from one end of the pond to the other. Reduction of turbidity from a construction site is almost entirely a function of cover measures and flow control. Temporary sediment traps and ponds are necessary to control the release rate of the runoff and to provide a catchment for sand-sized and larger soil particles, but are very ineffective at reducing the turbidity of the runoff. To mitigate the erosion hazards and potential for off-site sediment transport, we recommend the following: 1) The winter performance of a site is dependent on a well-conceived plan for control of site erosion and storm water runoff. It is easier to keep the soil on the ground than to remove it from storm water. The owner and the design team should include adequate ground-cover measures, access roads, and staging areas in the project bid to give the selected contractor a workable site. The selected contractor needs to be prepared to implement and maintain the required measures to reduce the amount of exposed ground. A site maintenance plan should be in place in the event storm water turbidity measurements are greater than the City of Seattle standards. 2) All TESC measures for a given area to be graded or otherwise worked should be installed prior to any activity within that area. The recommended sequence of construction within a given area would be to install sediment traps and/or ponds and establish perimeter flow control prior to starting mass grading. 3) During the wetter months of the year, or when large storm events are predicted during the summer months, each work area should be stabilized so that if showers occur, the February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 5 B-17 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington work area can receive the rainfall without excessive erosion or sediment transport. The required measures for an area to be â€œbuttoned-upâ€ will depend on the time of year and the duration the area will be left un-worked. During the winter months, areas that are to be left un-worked for more than 2 days should be mulched or covered with plastic. During the summer months, stabilization will usually consist of seal-rolling the subgrade. Such measures will aid in the contractorâ€™s ability to get back into a work area after a storm event. The stabilization process also includes establishing temporary storm water conveyance channels through work areas to route runoff to the approved treatment facilities. 4) All disturbed areas should be revegetated as soon as possible. If it is outside of the growing season, the disturbed areas should be covered with mulch, as recommended in the erosion control plan. Straw mulch provides the most cost-effective cover measure and can be made wind-resistant with the application of a tackifier after it is placed. 5) Surface runoff and discharge should be controlled during and following development. Uncontrolled discharge may promote erosion and sediment transport. Under no circumstances should concentrated discharges be allowed to flow over significant slopes. 6) Soils that are to be reused around the site should be stored in such a manner as to reduce erosion from the stockpile. Protective measures may include, but are not limited to, covering with plastic sheeting, the use of low stockpiles in flat areas, or the use of straw bales/silt fences around pile perimeters. During the period between October 1 and March 31, these measures are required. 7) On-site erosion control inspections and turbidity monitoring should be performed in accordance with City of Seattle requirements. Weekly and monthly reporting to Ecology should be performed on a regularly scheduled basis. TESC monitoring should be part of the weekly construction team meetings. Temporary and permanent erosion control and drainage measures should be adjusted and maintained, as necessary, at the time of construction. It is our opinion that with the proper implementation of the TESC plans and by field-adjusting appropriate mitigation elements (best management practices) during construction, as recommended by the erosion control inspector, the potential adverse impacts from erosion hazards on the project during construction can be mitigated. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 6 B-18 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington GEOTECHNICAL ENGINEERING RECOMMENDATIONS The medium dense Vashon recessional outwash encountered in the exploration pits is suitable for foundation support. Fill encountered within the exploration pits completed at the projectsite is not suitable for foundation. The following sections provide our recommendations for foundation support and support of slab-on-grade floors. Site Preparation Site preparation of planned structural fill pads, building foundations, and other areas should include removal of all vegetation, debris, wood fill and any other deleterious material. Areas where loose surficial soils exist due to grading/grubbing operations should be recompacted in place, or if this is not feasible due to either soil composition or moisture content, the loose soils should be removed and replaced as subsequently recommended for structural fill placement. The wood fill identified at the site and that may be encountered in other areas during grading operations should be removed from beneath all building and pavement areas. IN the exploration pits the depths of removal ranged from approximately 2 to 8 feet below the existing site grade. Areas where this material has been removed should be brought back to planned subgrade elevations with structural fill placed and compacted as described below. The existing crushed rock fill encountered in some of the explorations may be reused as structural fill if compacted to at least 95 percent of its maximum dry density as determined by ASTM D:1557. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes, however, we anticipate that temporary, unsupported cut slopes in the medium dense native sand may be made at a maximum slope of 1H:1V (Horizontal:Vertical). Additionally, if ground water seepage is observed, the temporary slopes may need to be readjusted. As is typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may have to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. Permanent cut slopes in medium dense native sediments or structural fill must not exceed a 2H:1V inclination. Fill slopes should either be overbuilt and trimmed back to final grade or surface compacted to a specified density. The native soils may be subject to disturbance when wet. The contractor must use care during site preparation and excavation operations so that the underlying soils are not softened. If disturbance occurs, the softened soils should be removed and the area brought to grade with structural fill. Consideration should be given to protecting access and staging areas with an appropriate section of crushed rock or asphalt treated base (ATB). February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 7 B-19 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington Foundation Support Conventional Spread Footings The foundation bearing stratum, consisting of either medium dense native Vashon sediments or structural fill placed over these sediments, is relatively shallow and spread footings may be used for foundation support. If needed, structural fill placed below foundation areas should consist of non-organic soil, free of deleterious materials, placed in maximum loose lift thicknesses of 8 inches with each lift compacted to at least 95 percent of the modified Proctor maximum dry density, as determined by American Society for Testing and Materials (ASTM): D 1557. Structural fill placed below footing areas should extend laterally beyond the footing edges a distance equal to or greater than the thickness of the fill. Sediments exposed in footing excavations should be compacted to a firm and unyielding condition prior to footing placement. For footings founded either directly on medium dense native Vashon outwash sediments, or on structural fill placed over these materials, we recommend that an allowable bearing pressure of 1,500 pounds per square foot (psf) be used for design purposes, including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. Perimeter footings for the proposed buildings should be buried a minimum of 18 inches into the surrounding soil for frost protection. No minimum burial depth is required for interior footings; however, all footings must penetrate to the prescribed stratum, and no footings should be founded in or above loose, organic, or existing fill soils. The area bounded by lines extending downward at 1H:1V (Horizontal:Vertical) from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM:D 1557. In addition, a 1. 5H:1V line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edges of steps or cuts in the bearing soils. All footing areas should be observed by SGP prior to placing concrete to verify that the exposed soils can support the design foundation bearing capacity and that construction conforms with the recommendations in this report. Foundation bearing verification may also be required by the governing municipality. Pipe Piles An alternative to removal of unsuitable fill soils would be the use of small diameter pipe piles for structural support of foundations or slabs. The number and spacing of the piles required February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 8 B-20 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington should be determined by a licensed structural engineer. The following table presents our recommendations for pipe pile capacities. Table 1: Small Diameter Pipe Pile Vertical Capacities Pipe Diameter (in) Pipe Schedule Hammer Size (lbs) Refusal Criteria Pipe Pile Capacity Seconds per Inch (Tons) 2 80 140 60 3 3 40 850 10 6 4 40 2,000 4 10 The pipe piles should be driven to the refusal criteria specified in Table 1 during a sustained period of continuous driving and the installation should be observed by a licensed engineer or engineering geologist. Should the pile contractor have different size/weight hammers than those specified in Table 1, different refusal criteria may apply. Resistance to lateral loads would be provided either by passive soil resistance against the existing foundation walls/footings and any new column pads/grade beams or installation of batter piles. A passive equivalent fluid pressure equal to 150 pounds per cubic foot (pcf) can be used for this purpose. All soil that is removed for pile installation and bracketing purposes must be replaced and compacted to a firm and unyielding condition. Also, all backfill around the new column pads should be placed as compacted structural fill (at least 95 percent of maximum dry density per ASTM D:1557) in order for this value to apply. We do not recommend assigning any lateral resistance to a pipe pile that is installed vertically. If batter piles are used to resist lateral loads for the new columns the lateral resistance would be equal to the horizontal component of the axial pile load. The maximum recommended batter is 1H:4V. The axial capacity of the pile is not reduced when battered at 1H:1V or less. Structural Fill Structural fill may be necessary to establish desired grades. All references to structural fill in this report refer to subgrade preparation, fill type, placement, and compaction of materials as discussed in this section. If a percentage of compaction is specified under another section of this report, the value given in that section should be used. Recycled crushed concrete that is less than 3 inches in diameter may be used for structural fill when compacted to a firm and unyielding condition as determined by the geotechnical engineer or engineering geologist. After stripping, planned excavation, and any required over-excavation have been performed to the satisfaction of the geotechnical engineer/engineering geologist, the upper 12 inches of exposed ground should be recompacted to a firm and unyielding condition. If the subgrade contains too much moisture, adequate recompaction may be difficult or impossible to obtain and should probably not be attempted. In lieu of recompaction, the area to receive fill should February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 9 B-21 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington be blanketed with washed rock or quarry spalls to act as a capillary break between the new fill and the wet subgrade. Where the exposed ground remains soft and further over-excavation is impractical, placement of an engineering stabilization fabric may be necessary to prevent contamination of the free-draining layer by silt migration from below. After recompaction of the exposed ground is approved, or a free-draining rock course is laid, structural fill may be placed to attain desired grades. Structural fill is defined as non-organic soil, acceptable to the geotechnical engineer/engineering geologist, placed in maximum 8-inch loose lifts with each lift being compacted to 95 percent of ASTM:D-1557. In the case of roadway and utility trench filling, the backfill should be placed and compacted in accordance with local codes and standards. The top of the compacted fill should extend horizontally outward a minimum distance of 3 feet beyond the location of the perimeter footings or roadway edges before sloping down at a maximum angle of 2H:1V. The contractor should note that any proposed fill soils must be evaluated by SGP prior to their use in fills. This would require that we have a sample of the material at least 72 hours in advance to perform a Proctor test and determine its field compaction standard. Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture-sensitive. Use of moisture-sensitive soil in structural fills should be limited to favorable dry weather and dry subgrade conditions. The on-site soils contained some amount of silt and are considered moisture-sensitive when excavated and used as fill materials. Construction equipment traversing the site when the soils are wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction cannot be obtained, a select import material consisting of a clean, free-draining gravel and/or sand should be used. Free-draining fill consists of non-organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction and at least 25 percent retained on the No. 4 sieve. Slab-on-Grade Floor Support Slab-on-grade floors may be constructed either directly on the undisturbed, medium dense native Vashon sediments, or on structural fill placed over these materials. Areas of the slab subgrade that are disturbed (loosened) during construction should be recompacted to an unyielding condition prior to placing the pea gravel, as described below. In order to control moisture vapor transfer through the slab, slab-on-grade floors should be constructed atop a capillary break consisting of a minimum thickness of 4 inches of washed pea gravel, washed crushed rock or other suitable material approved by the geotechnical engineer February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 10 B-22 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington or engineering geologist. The capillary break should be overlain by a 10-mil (minimum thickness) plastic vapor retarder. Foundation Walls All backfill behind foundation walls or around foundation units should be placed as per our recommendations for structural fill and as described in this section of the report. Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be designed to resist active lateral earth pressure represented by an equivalent fluid equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid of 50 pcf. Walls with sloping backfill up to a maximum gradient of 2H:1V should be designed using an equivalent fluid of 55 pcf for yielding conditions or 75 pcf for fully restrained conditions. If parking areas are adjacent to walls, a surcharge equivalent to 2 feet of soil should be added to the wall height in determining lateral design forces. As required by the 2015 IBC, retaining wall design should include a seismic surcharge pressure in addition to the equivalent fluid pressures presented above. Considering the site soils and the recommended wall backfill materials, we recommend a seismic surcharge pressure of 8H and 10H psf, where H is the wall height in feet for the â€œactiveâ€ and â€œat-restâ€ loading conditions, respectively. The seismic surcharge should be modeled as a rectangular distribution with the resultant applied at the midpoint of the walls. The lateral pressures presented above are based on the conditions of a uniform backfill consisting of excavated on-site soils, or imported structural fill compacted to 90 percent of ASTM:D 1557. A higher degree of compaction is not recommended, as this will increase the pressure acting on the walls. A lower compaction may result in settlement of the slab-on-grade or other structures supported above the walls. Thus, the compaction level is critical and must be tested by our firm during placement. Surcharges from adjacent footings or heavy construction equipment must be added to the above values. Perimeter footing drains should be provided for all retaining walls, as discussed under the â€œDrainage Considerationsâ€ section of this report. It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against the walls. This would involve installation of a minimum 1-foot-wide blanket drain to within 1 foot of finish grade for the full wall height using imported, washed gravel against the walls. Passive Resistance and Friction Factors Lateral loads can be resisted by friction between the foundation and the natural glacial soils or supporting structural fill soils, and by passive earth pressure acting on the buried portions of February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 11 B-23 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington the foundations. The foundations must be backfilled with structural fill and compacted to at least 95 percent of the maximum dry density to achieve the passive resistance provided below. We recommend the following allowable design parameters: â€¢ Passive equivalent fluid = 250 pcf â€¢ Coefficient of friction = 0.35 All perimeter footing walls should be provided with a drain at the base of the footing elevation. Drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set at or slightly below the bottom of the footing and the drains should be constructed with sufficient gradient to allow gravity discharge away from the buildings. Roof and surface runoff should not discharge into the footing drain system but should be handled by a separate, rigid, tightline drain. In planning, exterior grades adjacent to foundations should be sloped downward away from the structures to achieve surface drainage. Drainage Considerations All perimeter footing walls should be provided with a drain at the base of the footing elevation. Drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set at or slightly below the bottom of the footing and the drains should be constructed with sufficient gradient to allow gravity discharge away from the buildings. Roof and surface runoff should not discharge into the footing drain system but should be handled by a separate, rigid, tightline drain. In planning, exterior grades adjacent to foundations should be sloped downward away from the structures to achieve surface drainage. PROJECT DESIGN AND CONSTRUCTION MONITORING Our report is based on a general project concept provided by the owner. We recommend that SGP be allowed to review this report and update it as needed when a more detailed project plan has been developed. In this way, we can confirm that our earthwork and foundation recommendations have been properly interpreted and implemented in the design. This review is not included in our current scope of work and budget. We are also available to provide geotechnical recommendations in the event that variations in subsurface conditions become apparent and earthwork monitoring services during construction. The integrity of the foundation system depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the services are not part of this current scope of work. If these services are desired, please let us know, and we will prepare a cost proposal. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 12 B-24 B-25 J-0045 FIGURE 1 SITE VICINITY MAP GAYTEWAY BUSINESS PARK ARLINGTON, WASHINGTON B-26 SITE AREA 79,102 SF ( 1.8 ACRES) STORAGE YARD "A' SITE AREA 142,510 SF (3.3 ACRES) BUILDING B SITE AREA 186,210 SF ( 4.3 ACRES) BUILDING C SITE AREA 408,000 SF (9.3 ACRES) TOTAL SITE AREA Exploration Pit Number and 22,842 SF (.5 ACRES) PROPOSED EASEMENT OVER RR Approximate Location EP-1 STORAGE YARD 'A' BUILDING AREA 79.102 SF 65,950 SF BUILDING "B" 2 Thickness of Wood Fill in Feet 66,100 SF BUILDING "C" D 50,660 SF WAREHOUSE 20' EASEMENT -Â D 9,003 SF RESTAURANT/TAVERN OVER RR D 2,665 SF OFFICE/STORAGE D 3,484 SF DISTILLERY n 288 SF SERVICE CORRIDOR EP-11 132,050 SF TOTAL BUILDING AREA ON SITE 6 ZONE GI GENERAL INDUSTRIAL EP-10 PARKING= BUILDING B 25 STALLS -( 15%) 9,892.5 SF OFFICE @ 1 / 400 EP-12 29 STALLS - (85%) 56,057.5 SF WHSE @ 1 /2,000 54 TOTAL STALLS REQUIRED BUILDING 'B' EP-9 65950 S 58 STALLS PROVIDED ,___I----+---+ BUILDING C 19 STALLS-(15%) 7,599 SF OFFICE @ 1/400 22 STALLS - (85%) 43,061 SF WHSE @ 1 /2,000 37 STALLS - 9,003 SF RESTAURANT/TAVERN @ 4/1,000 + 2 STALLS - 288 SF SERVICE CORRIDOR @ 4/1,000 7 STALLS - 2,665 SF OFFICE @ 1 / 400 2 STALLS - 3.484 SF DISTILLERY @ 1 /2000 EP-8 EP-7 89 TOTAL STALLS REQUIRED 128 STALLS PROVIDED TOTAL SITE 143 TOTAL STALLS REQUIRED 186 TOTAL STALLS PROVIDED DOCK DOORS T 11 BUILDING "B" T 10 BUILDING "c" EP-6 EP-5 21 TOTAL DOCK DOORS PROVIDED 5 DRIVE-IN DOORS v 2 BUILDING "B" EP-4 V 4 BUILDING "C" 6 TOTAL DOCK DOORS PROVIDED 5 EP-3 3 EP-2 8 EP-1 2 SITE AND EXPLORATION PLAN (l 111111111 n I I I I I I I IC) GAYTEWAY BUSINESS PARK 30' PRIVATE ROAD BUILDINGS B AND C ARLINGTON, WASHINGTON & $NORTH J-0045 FIGURE 2 GAYTEWAY BUSINESS PARK - BLDG. B C cï¿½ 20015 67TH AVENUE NE GA YTEW A Y LLC. ARLINGTON, WA B-27 arc h it ec ts 01I12I201a 1â€¢-soâ€¢-0â€¢ SITE AREA 408,000 SF (9.36 ACRES) BUILDING AREA 105,000 SF BUILDING B 17 100 SF BUILDING C --n 122,100 SF TOTAL I-6 1 PARKING: â–¡111111111111111 PARKING LOT A ï¿½ 180 STALLS PROVIDED PARKING LOT A -----+-1==------ BUILDING B 011111111111111 ï¿½ 115 STALLS PROVIDED 180 STALLS BUILDING C â–¡1111111111111ï¿½ 63 STALLS PROVIDED TOTAL SITE 358 TOTAL STALLS PROVIDED 01111111111110 I-3 7 175'-0" J I 1 i I J I-5 I-5 Sample Number and I Approximate Location 1 'b i ï¿½ I ï¿½ J BUILDING B 105,000 SF I 1 'b i I I 0 0 c.o w z w ::::> z I-2 ï¿½ I-4 7 b J I 0 76'-5" 180'-0" 'b I-1 BUILDING C I 17,100 SF rn o 111111111n111111110 NORTH INFILTRATION SOIL SAMPLE LOCATIONS GAYTEWAY BUSINESS PARK ARLINGTON, WASHINGTON $ 1' = 100' J-0045 FIGURE 2 GA YTEWAY BUSINESS PARK - SITE PLAN cï¿½ ARLINGTON, WASHINGTON GA YTEW A Y LLC. a r C h I t e C t s 04/04/18 B-28 EXPLORATION HOLE LOGS GAYTEWAY BUSINESS PARK BUILDINGS ARLINGTON, WASHINGTON EP-1 Depth (ft) Description FILL 0.0 â€“ 2.0 Loose, moist, dark brown, silty fine SAND with wood fragments RECESSIONAL OUTWASH 2.0 â€“ 4.0 Medium dense, moist, oxidized orange-brown, silty, SAND (Weathered). 4.0 â€“ 11.0 Medium dense, moist, brown to gray, gravelly SAND with lenses of gravel. T.D. @ 11.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-2 Depth (ft) Description FILL 0.0 â€“ 8.0 Loose, moist, brown, silty SAND with numerous wood fragments and small logs RECESSIONAL OUTWASH 8.0 â€“ 11.5 Medium dense, moist, gray, SAND with some gravel. T.D. @ 11.5 feet 1-22-18. No ground water seepage encountered. No sidewall caving. B-29 EP-3 Depth (ft) Description FILL 0.0 â€“ 3.0 Loose. Moist, brown, SAND with organics, concrete and some gravel. RECESSIONAL OUTWASH 3.0 â€“ 12.0 Medium dense, moist, brown to gray, gravelly SAND with lenses of gravel. T.D. @ 12.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-4 Depth (ft) Description FILL 0.0 â€“ 5.0 Loose, moist, dark brown, sand with wood fragments, roots and small logs. RECESSIONAL OUTWASH 5.0 -10.0 medium dense, moist, gray, sandy GRAVEL to gravelly SAND. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-5 . Depth (ft) Description FILL 0.0 â€“ 4.0 Loose, moist, tan, crushed rock FILL. RECESSIONAL OUTWASH 4.0 â€“ 9.0 Medium dense, moist, gray, gravelly SAND. T.D. @ 9.0 feet 1-22-18. No ground water seepage encountered. B-30 EP-6 Depth (ft) Description FILL 0.0 â€“ 1.0 Loose, moist, tan crushed rock F ILL. 1.0 â€“ 5.0 Soft, moist, dark brown, silty topsoil with wood fragments, roots and logs. RECESSIONAL OUTWASH 5.0 â€“ 12.0 Medium dense, moist, oxidized brown to gray, sandy GRAVEL to gravelly SAND. T.D. @ 12.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-7 . Depth (ft) Description RECESSIONAL OUTWASH 0.0 â€“ 1.5 Loose, moist, oxidized orange-brown, silty fine SAND (Weathered). 1.5 -10.0 Medium dense, moist, gray, sandy GRAVEL to gravelly SAND. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-8 Depth (ft) Description RECESSIONAL OUTWASH 0.0 â€“ 2.0 Loose, moist, oxidized orange-brown, silty fine SAND and gray sandy GRAVEL (Weathered) 2.0 â€“ 10.0 Medium dense, moist, gray, sandy GRAVEL with lenses of sand with some gravel. T.D. @ 10.0 feet. No ground water seepage encountered. No sidewall caving. B-31 EP-9 . Depth (ft) Description FILL 0.0 -4.0 Loose to medium dense, moist, brown to gray, silty SAND and gravelly SAND (Utility trench Fill). RECESSIONAL OUTWASH 4.0 â€“ 9.0 Medium dense, moist, gray, sandy GRAVEL and gravelly SAND. T.D. @ 8.0 feet 3-30-17. Slow ground water seepage at 6.5 feet. EP-10 Depth (ft) Description FILL 0.0 â€“ 1.0 Loose, moist, oxidized brown to brown, SAND with scattered organics. RECESSIONAL OUTWASH 1.0 â€“ 12.0 Medium dense, moist, brown to gray, sandy GRAVEL to gravelly SAND. T.D. @ 12.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-11 Depth (ft) Description FILL 0.0 â€“ 2.0 Loose, moist, brown to gray, SAND with scattered debris 2.0 â€“ 6.0 Soft, moist, dark brown, wood chips and lumber fragments. RECESSIONAL OUTWASH 6.0 -8.0 Medium dense, moist, gray sandy GRAVEL 8.0 â€“ 10.0 Medium dense, moist, gray SAND. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. B-32 EP-12 Depth (ft) Description FILL 0.0 â€“ 3.0 Loose, moist, brown, sandy Gravel with scattered wood fragments and log rounds RECESSIONAL OUTWASH 3.0 â€“ 10.0 Medium dense, moist, brown, sandy GRAVEL 10.0 â€“ 12.0 Medium dense, moist, gray, SAND with some gravel. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving B-33 IP-1 Ground surface elevation 141.5 feet Depth (ft) Description 0.0 â€“ 0.75 Topsoil 0.75 â€“ 3.5 Loose to medium dense, moist, oxidized brown, slightly silty to silty sand with some gravel. T.D. @ 3.5 feet 3-30-17. No ground water seepage. IP-2 Ground surface elevation 129.5 Depth (ft) Description 0.0 â€“ 0.75 Topsoil 0.75 â€“ 1.0 Loose, moist, oxidized brown, silty sand with gravel. T.D. @ 1.0 feet 3-30-17. No ground water seepage. IP-3 Ground surface elevation 137.0. Depth (ft) Description 0.0 â€“ 0.5 Topsoil 0.5 â€“ 3.0 Loose to medium dense, moist, oxidized brown, silty sand with gravel. T.D. @ 3.0 feet 3-30-17. No groundwater seepage. IP-4 Ground surface elevation at 134.5 Depth (ft) Description 0.0 â€“ 1.0 Topsoil. T.D. @ 1.0 feet. Bottom of exploration at the top of the native sand below the topsoil. No groundwater seepage. B-34 IP-5 Ground surface elevation 136.5 Depth (ft) Description 0.0 â€“ 0.75 Topsoil with abundant roots 0.75 â€“ 3.25 Loose to medium dense, gray to brown, silty sand with gravel. 3.25 â€“ 5.0 Dense, saturated, gray to brown, fine sandy silt to clayey silt. T.D. @ 3.25 feet 3-30-17. Moderate groundwater seepage at 3.25 feet. IP-6 Ground surface elevation 139.0 feet. Depth (ft) Description 0.0 â€“ 1.0 Topsoil with abundant roots. 1.0 â€“ 4.5 Medium dense, moist to saturated, gray to oxidized brown, slightly silty sand. T.D. @ 4.5 feet 3-30-17. Moderate groundwater seepage at 3.0 feet. IP-7 Ground surface elevation 141.5 feet Depth (ft) Description 0.0 â€“ 0.75 Topsoil 0.75 â€“ 4.0 Medium dense, moist to saturated, mottled gray to oxidized brown, slightly silty sand with some gravel and thin clayey silt interbeds. T.D. @ 4.0 feet. Slow groundwater seepage at 2.5 feet. IP-8 Ground surface elevation 146.5 Depth (ft) Description 0.0 â€“ 1.0 Topsoil 1.0 â€“ 3.5 Loose to medium dense, oxidized brown, slightly silty to silty, sand with some gravel. T.D. @ 3.5 feet 3-30-17. No groundwater seepage. B-35 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX C â€“ STORM OPERATION & MAINTENANCE MANUAL C-1 TERRAFORMA DES I GN GROUP STORMWATER OPERATION AND MAINTENANCE MANUAL _________________________________________________________________ GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ LOCATION: 20015 67TH AVENUE NE ARLINGTON, WA 98223 ISSUE DATE: March 5, 2019 PREPARED FOR: GAYTEWAY, LLC Contact: Chris Gayte Phone: (206) 240-9739 PREPARED BY: Terraforma Design Group, Inc. 5027 51st Avenue SW Seattle, WA 98136 TDG No. 18005 C I V I L E N G I N E E R I N G & L A N D S C A P E A R C H I T E C T U R E 5027 51st Avenue SW Seattle WA 98136 phone 206.923.0590 website www.terraformadesigngroup.com C-2 1. Introduction The proposed development consists of a new office / warehouse / manufacturing building located at 20015 67th Avenue NE. The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 (west side of railroad tracks) and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. Onsite drainage improvements include new catch basins and storm drainage for surface runoff. Stormwater infiltration will be proposed for the proposed parking, landscaping and roof drainage runoff; underground infiltration chambers are proposed at this time. Runoff Treatment will be provided for the pavement areas via a Bayfilter Treatment Manhole prior to discharge to infiltration galleries. The specific purpose for the stormwater facilities is to minimize pollution that is typically associated with modern development, i.e. pollution from motor vehicles and pollution generated from erosion. This report provides guidelines to the owner for storm water facility maintenance. A copy of this manual shall be retained onsite or within reasonable access to the site (see Section 3), and shall be transferred with the property to any successors. 2. On-Site Stormwater Facility Maintenance Requirements Regular inspections of the drainage facilities should be carried on a consistent basis as provided within the maintenance guidelines included is this report. The responsible party should keep records of these inspections available for review by the governing agency. Additional inspections may be required after severe seasonal storms. Routine maintenance of the site will include mowing, care of landscaping and the removal of trash and debris from the drainage system. The parking lots and driveways should be kept clean and in repair. Events such as major storms or heavy winds will require immediate inspections for damages. 3. O&M Location, Accessibility and Responsible Organizations This Operation and Maintenance manual shall be stored within Building â€˜Bâ€™ at 20015 67th Avenue NE and shall be made available for inspection by the governing agency. Responsible Organization: GAYTEWAY, LLC Contact: Chris Gayte Phone: (206) 240-9739 C-3 4. Description of Drainage Elements The following is a list of the on-site storm drainage facilities and their function. Also attached are the required maintenance requirements for these facilities. Infiltration Trenches (Stormtech) â€“ Stormtech chamber / rock gallery allows for stormwater infiltration into the native granular soils, Catch Basins and Inlets â€“ provides runoff catchment from pavement and planter areas, Manufactured Media Filter (Bayfilter) â€“ water quality treatment 5. Maintenance Activity Log, Recordkeeping & Reports The following pages contain maintenance tables for the stormwater BMPs. The Ownerâ€™s representative or hired maintenance company shall adhere to the following maintenance guidelines and schedule. The attached checklist shall be completed by the maintenance person and filed within Appendix A. Drainage facilities shall be inspected and maintained at least annually, unless noted otherwise in the attached tables. The following keynotes explain the required frequency of a maintenance activity. â€¢ (A) Annually, once in late summer (preferably September) â€¢ (M) Monthly from October through April. â€¢ (S) Storm-based, after any major storm (use 1 inch in 24 hours as a guideline). The following tables contained shall be used as checklists. Maintenance personnel may use photocopies of these pages and check off items inspected and problems noted during each inspection. Actions taken and corrective action recommended should also be noted. This Operation and Maintenance manual shall be stored within the Chevron convenience store in the managerâ€™s office and shall be made available for inspection by the governing agency. The Ownerâ€™s representative or hired maintenance company shall submit an annual report to CITY OF TUMWATER regarding implementation of the programs referenced in (1) and (2) above. The report must be submitted on or before May 15th of each calendar year and shall contain, at a minimum, the following: (a) Name, address, and telephone number of the business, the person, or the firm responsible for plan implementation, and the person completing the report. (b) Time period covered by the report. (c) A chronological summary of activities conducted to implement the programs referenced in (1) and (2) above. A photocopy of the applicable sections of the log book with any additional explanation needed shall normally suffice. For any activities conducted by paid parties not affiliated with OWNER, include a copy of the invoice for services. (d) An outline of planned activities for the next year. C-4 C-5 INSPECTION/MAINTENANCE CHECKLIST LOCATION: LOT 2 - 20015 67TH AVENUE NE, ARLINGTON, WA 98223 STRUCTURE DATE OF INSPECTION/MAINTENANCE Results/ Maintenance Date Comments Stormtech Chambers Inspection Results Maintenance Done Catch Basins Inspection Results Maintenance Done Manufactured Media Inspection Filter / Bayfilter Results Maintenance Done Inspection Results Maintenance Done Inspection Results Maintenance Done * A COPY OF THIS MAINTENANCE LOG SHALL BE COMPLETED BY A DESIGNATED MAINTENANCE PERSON PER THE REQUIRED MAINTENANCE INTERVALS AND FILED WITHIN APPENDIX A. THESE MAINTENANCE LOGS SHALL BE KEPT ON-SITE C-6 12.0 Inspection & Maintenance STORMTECH ISOLATORâ„¢ ROW - STEP-BY-STEP 12.3 ECCENTRIC PIPE HEADER INSPECTION MAINTENANCE PROCEDURES Theses guidelines do not supercede a pipe manufac- turerâ€™s recommended I&M procedures. Consult with the Step 1) Inspect Isolator Row for sediment manufacturer of the pipe header system for specific I&M procedures. Inspection of the header system should A) Inspection ports (if present) be carried out quarterly. On sites which generate higher i. Remove lid from floor box frame levels of sediment more frequent inspections may be ii. Remove cap from inspection riser necessary. Headers may be accessed through risers, access ports or manholes. Measurement of sediment iii. Using a flashlight and stadia rod, measure may be taken with a stadia rod or similar device. Clean - depth of sediment out of sediment should occur when the sediment volume iv. If sediment is at, or above, 3" (76 mm) has reduced the storage area by 25% or the depth depth proceed to Step 2. If not proceed of sediment has reached approximately 25% of the to Step 3. diameter of the structure. B) All Isolator Rows 12.4 ECCENTRIC PIPE MANIFOLD MAINTENANCE i. Remove cover from manhole at upstream Cleanout of accumulated material should be accom- end of Isolator Row plished by vacuum pumping the material from the head- ii. Using a flashlight, inspect down Isolator er. Cleanout should be accomplished during dry weath- Row through outlet pipe er. Care should be taken to avoid flushing sediments out 1. Follow OSHA regulations for confined through the outlet pipes and into the chamber rows. space entry if entering manhole Eccentric Header Step-by-Step Maintenance 2. Mirrors on poles or cameras may be Procedures used to avoid a confined space entry 1. Locate manholes connected to the manifold system iii. If sediment is at or above the lower row of 2. Remove grates or covers sidewall holes [approximately 3" (76 mm)] 3. Using a stadia rod, measure the depth of sediment proceed to Step 2. If not proceed to Step 3. 4. If sediment is at a depth of about 25% pipe volume Step 2) Clean out Isolator Row using the JetVac process or 25% pipe diameter proceed to step 5. If not proceed to step 6. A) A fixed floor cleaning nozzle with rear 5. Vacuum pump the sediment. Do not flush sediment facing nozzle spread of 45" (1143 mm) or out inlet pipes. more is preferable 6. Replace grates and covers B) Apply multiple passes of JetVac until back- 7. Record depth and date and schedule next inspection flush water is clean C) Vacuum manhole sump as required during Figure 21 â€“ Eccentric Manifold Maintenance jetting 1, 2, 6 Step 3) Replace all caps, lids and covers Step 4) Inspect and clean catch basins and manholes upstream of the StormTech system following local guidelines. 3, 4, 5 Figure 20 â€“ StormTech Isolator Row (not to scale) 1) B) 1) A) 2 Please contact StormTechâ€™s Technical Services Department at 888-892-2894 for a spreadsheet to 4 estimate cleaning intervals. 23 Call StormTech at 860.529.8188 or 888.892.2694 or visit our website at www.stormtech.com for technical and product information. C-7 CITY OF TUMWATER DRAINAGE DESIGN and EROSION CONTROL MANUAL Table C-13. Maintenance Checklist for Catch Basins and Inlets Drainage Systems Conditions that Shall Frequency Feature âˆš Problem Conditions to Check For Exist M,S General Trash and Trash, debris, and No trash or debris located Debris sediment in or on basin immediately in front of catch basin opening. Grate is kept clean and allows water to enter. M Sediment or debris (in the No sediment or debris in basin) that exceeds 1/3 the catch basin. Catch the depth from the bottom basin is dug out and of basin to invert of the clean. lowest pipe into or out of the basin. M,S Trash or debris in any Inlet and outlet pipes free inlet or outlet pipe of trash or debris. blocking more than 1/3 of its height. M Structural Corner of frame extends Frame is even with curb. Damage to more than 3/4 inch past Frame and/or curb face into the street Top Slab (if applicable). M Top slab has holes larger Top slab is free of holes than 2 square inches or and cracks. cracks wider than 1/4 inch (intent is to make sure no material is running into basin). M Frame not sitting flush on Frame is sitting flush on top slab, i.e., separation the riser rings or top slab of more than 3/4 inch of and firmly attached. the frame from the top slab. Frame not securely attached. A Cracks in Basin Cracks wider than Basin replaced or Walls/ Bottom 1/2 inch and longer than repaired to design 3 feet, any evidence of standards. Contact a soil particles entering professional engineer for catch basin through evaluation. cracks, or maintenance person judges that structure is unsound. A Cracks wider than No cracks more than 1/2 inch and longer than 1/4 inch wide at the joint 1 foot at the joint of any of inlet/outlet pipe. inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. C-22 Volume V â€“ Stormwater BMPs December 2009 C-8 CITY OF TUMWATER DRAINAGE DESIGN and EROSION CONTROL MANUAL Drainage Systems Conditions that Shall Frequency Feature âˆš Problem Conditions to Check For Exist A Settlement/ Basin has settled more Basin replaced or Misalignment than 1 inch or has rotated repaired to design more than 2 inches out of standards. Contact a alignment. professional engineer for evaluation. M Vegetation Vegetation growing No vegetation blocking across and blocking more opening to basin. than 10 percent of the basin opening. M Vegetation Vegetation growing in No vegetation or root inlet/outlet pipe joints that growth present. is more than 6 inches tall and less than 6 inches apart. If you are unsure whether a problem exists, please contact Tumwater and ask for technical assistance. Key: A = Annual (March or April preferred) M = Monthly (see schedule) S = After major storms December 2009 Volume V â€“ Stormwater BMPs C-23 C-9 Table V-4.5.2(15) Maintenance Standards - Manufactured Media Filters (continued) Results Expected Maintenance Condition When Maintenance is Defect When Maintenance Component Needed is Performed its which would mulation on impede permeability Media. of the compost media. Sediment Accu- No sediment depos- Sediment depth exceeds 6-inches mulation in its in vault bottom of in first chamber. Vault first chamber. Trash and debris Trash/Debris Trash and debris accumulated on removed from the Accumulation compost filter bed. compost filter bed. Sediment in When drain pipes, clean-outs, Drain Sediment and debris become full with sediment and/or Pipes/Clean- removed. debris. Outs Any part of the pipes that are Damaged Pipe repaired and/or crushed or damaged due to cor- Pipes replaced. rosion and/or settlement. Cover cannot be opened; one per- Cover repaired to Access Cover son cannot open the cover using proper working spe- Damaged/Not normal lifting pressure, cor- cifications or Working rosion/deformation of cover. replaced. Cracks wider than 1/2-inch or evid- Vault replaced or ence of soil particles entering the repairs made so that Vault Structure structure through the cracks, or vault meets design Includes maintenance/inspection personnel specifications and is Cracks in Wall, determine that the vault is not struc-structurally sound. Bottom, turally sound. Damage to Vault repaired so that Frame and/or Cracks wider than 1/2-inch at the no cracks exist wider Top Slab joint of any inlet/outlet pipe or evid- than 1/4-inch at the ence of soil particles entering joint of the inlet/outlet through the cracks. pipe. Baffles corroding, cracking warp- Baffles repaired or ing, and/or showing signs of failure Baffles replaced to spe- as determined by main- cifications. tenance/inspection person. 2014 Stormwater Management Manual for Western Washington C-10 Volume V - Chapter 4 - Page 854 Table V-4.5.2(15) Maintenance Standards - Manufactured Media Filters (continued) Results Expected Maintenance Condition When Maintenance is Defect When Maintenance Component Needed is Performed Ladder replaced or Ladder is corroded or deteriorated, repaired and meets not functioning properly, not Access Ladder specifications, and is securely attached to structure wall, Damaged safe to use as determ- missing rungs, cracks, and mis- ined by inspection aligned. personnel. Drawdown of water through the Media cartridges Below Media media takes longer than 1 hour, replaced. Ground Cart- and/or overflow occurs frequently. ridge Type Flows do not properly enter filter Filter cartridges Short Circuiting cartridges. replaced. Table V-4.5.2(16) Maintenance Standards - Baffle Oil/Water Separators (API Type) Results Expected Maintenance Condition When Main- Defect When Maintenance is Component tenance is Needed Performed Effluent discharge from Inspection of discharge vault should be clear Monitoring water for obvious signs of with out thick visible poor water quality. sheen. No sediment deposits on vault bottom that Sediment depth in bottom of Sediment Accu- would impede flow vault exceeds 6-inches in mulation through the vault and depth. reduce separation effi- General ciency. Trash and debris accu- Trash and debris Trash and Debris mulation in vault, or pipe removed from vault, Accumulation inlet/outlet, floatables and and inlet/outlet piping. non-floatables. Extract oil from vault by Oil accumulations that vactoring. Disposal in Oil Accumulation exceed 1-inch, at the surface accordance with state of the water. and local rules and reg- ulations. 2014 Stormwater Management Manual for Western Washington C-11 Volume V - Chapter 4 - Page 855 BAYSAVE R TECHNOLOGI ES, I N C. Chapter 4 Maintenance of the BayFilterâ„¢ System The BayFilterâ„¢ system requires periodic maintenance to continue operating at the design efficiency. The maintenance process comprises the removal and replacement of each BayFilterâ„¢ cartridge and drain down module and the cleaning of the vault or manhole with a vacuum truck. BayFilterâ„¢ maintenance should be performed by a BaySaver Technologies, Inc. certified maintenance contractor. The maintenance cycle of the BayFilterâ„¢ system will be driven mostly by the actual solids load on the filter. The system should be periodically monitored to be certain it is operating correctly. Since stormwater solids loads can be variable, it is possible that the maintenance cycle could be more or less than the projected duration. The BayFilter systems in New Development applications are designed to treat the WQv in 24 hours initially. Later in the cycle these cartridges will flow at a slower rate, and when the WQv does not drain down within +/- 40 hours after the storm event, the system must be maintained. When a BayFilterâ„¢ system is first installed, it is recommended that it be inspected every six (6) months. When the filter system exhibits flows below design levels the system should be maintained. Filter cartridge replacement should also be considered when sediment levels are at or above the level of the 4 inch manifold system. Please contact the BaySaver Technologies Inc. Engineering Department for maintenance cycle estimations or assistance at 1.800.229.7283. 22 C-12 BAYSAVE R TECHNOLOGI ES, I N C. Maintenance Procedures 1. Remove the manhole covers and open all access hatches. 2. Before entering the system make sure the air is safe per OSHA Standards or use a breathing apparatus. Use low O2, high CO, or other applicable warning devices per regulatory requirements. 3. Using a vacuum truck remove any liquid and sediments that can be removed prior to entry. 4. Using a small lift or the boom of the vacuum truck, remove the used cartridges by lifting them out. 5. Any cartridges that cannot be readily lifted directly out of the vault should be removed from their location and carried to the lifting point using the Trolley system installed in the Vault (if applicable). 6. When all cartridges and drain down modules are removed, remove the balance of the solids and water; then loosen the stainless clamps on the Fernco couplings in the pipe manifold; remove the drain pipes as well. Carefully cap the manifold and the Ferncoâ€™s and rinse the floor removing the balance of the collected solids. 7. Clean the manifold pipes, inspect, and reinstall. 8. Install the exchange cartridges and close all covers. 9. The used cartridges must be sent back to BaySaver Technologies, Inc. for exchange/recycling and credit on undamaged units. 23 C-13 APPENDIX A - FILED MAINTENANCE RECORDS C-14 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX D - CIVIL DESIGN C1.5 â€“ STORM PLAN C2.3 â€“ STORM DETAILS C2.4 â€“ STORM DETAILS ORMA F ERRA T DESIGN GROUP, INC. C1.5 INFILTRATION GALLERY 'A' - PLAN VIEW COVER PIPE CONNECTION TO END CAP WITH ADS INFILTRATION GALLERY 'A' - SECTION GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE MC-3500 CHAMBER INSTALL UNDER ISOLATOR ROW INSPECTION & MAINTENANCE (NORTH ROW) TWO LAYERS OF ADS STEP 1) INSPECT ISOLATOR ROW FOR SEDIMENT GEOSYNTHETICS 315WTM WOVEN A. INSPECTION PORTS (IF PRESENT) GEOTEXTILE BETWEEN FOUNDATION A.1. REMOVE/OPEN LID ON NYLOPLAST INLINE DRAIN STONE AND CHAMBERS. A.2. REMOVE AND CLEAN FLEXSTORM FILTER IF INSTALLED 8.3-FT MIN. WIDTH STRIPS (MC-3500). A.3. USING A FLASHLIGHT AND STADIA ROD, MEASURE DEPTH OF SEDIMENT AND RECORD ON MAINTENANCE LOG A.4. LOWER A CAMERA INTO ISOLATOR ROW FOR VISUAL INSPECTION OF SEDIMENT LEVELS (OPTIONAL) ORMA A.5. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, F PROCEED TO STEP 3. ACCEPTABLE FILL MATERIALS: STORMTECH MC-3500 CHAMBER SYSTEMS B. ALL ISOLATOR ROWS JLM JLM B.1. REMOVE COVER FROM STRUCTURE AT UPSTREAM END OF ISOLATOR AASHTO MATERIAL COMPACTION / DENSITY ROW MATERIAL LOCATION DESCRIPTION B.2. USING A FLASHLIGHT, INSPECT DOWN THE ISOLATOR ROW THROUGH CLASSIFICATIONS REQUIREMENT OUTLET PIPE FINAL FILL: FILL MATERIAL FOR LAYER 'D' STARTS i) MIRRORS ON POLES OR CAMERAS MAY BE USED TO AVOID A FROM THE TOP OF THE 'C' LAYER TO THE BOTTOM ANY SOIL/ROCK MATERIALS, NATIVE SOILS, OR PER PREPARE PER SITE DESIGN ENGINEER'S PLANS. D OF FLEXIBLE PAVEMENT OR UNPAVED FINISHED ENGINEER'S PLANS. CHECK PLANS FOR PAVEMENT N/A PAVED INSTALLATIONS MAY HAVE STRINGENT CONFINED SPACE ENTRY ERRA GRADE ABOVE. NOTE THAT PAVEMENT SUBBASE SUBGRADE REQUIREMENTS. MATERIAL AND PREPARATION REQUIREMENTS. MC-3500 TY. 2 - 54" CB ii) FOLLOW OSHA REGULATIONS FOR CONFINED SPACE ENTRY IF MAY BE PART OF THE 'D' LAYER ENTERING MANHOLE DESIGN GROUP, INC. AASHTO M145Â¹ 24" (600 mm) HDPE ACCESS PIPE T BEGIN COMPACTIONS AFTER 24" (600 mm) OF 11/18/14 B.3. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, A-1, A-2-4, A-3 INITIAL FILL: FILL MATERIAL FOR LAYER 'C' GRANULAR WELL-GRADED SOIL/AGGREGATE MIXTURES, <35% MATERIAL OVER THE CHAMBERS IS REACHED. REQUIRED USE FACTORY PROCEED TO STEP 3. STARTS FROM THE TOP OF THE EMBEDMENT FINES OR PROCESSED AGGREGATE. COMPACT ADDITIONAL LAYERS IN 12" (300 mm) PRE-CORED END CAP OR C STONE ('B' LAYER) TO 24" (600 mm) ABOVE THE MAX LIFTS TO A MIN. 95% PROCTOR DENSITY FOR TOP OF THE CHAMBER. NOTE THAT PAVEMENT MOST PAVEMENT SUBBASE MATERIALS CAN BE USED IN LIEU AASHTO M43Â¹ WELL GRADED MATERIAL AND 95% RELATIVE STANDARD CROSS SECTION PART #: MC3500IEPP24BC STEP 2) CLEAN OUT ISOLATOR ROW USING THE JETVAC PROCESS SUBBASE MAY BE A PART OF THE 'C' LAYER. OF THIS LAYER. 3, 357, 4, 467, 5, 56, 57, 6, 67, 68, 7, 78, 8, 89, DENSITY FOR PROCESSED AGGREGATE A. A FIXED CULVERT CLEANING NOZZLE WITH REAR FACING SPREAD OF 45" MATERIALS. 9, 10 MC-3500 SECTION (1.1 m) OR MORE IS PREFERRED EMBEDMENT STONE: FILL SURROUNDING THE NTS B. APPLY MULTIPLE PASSES OF JETVAC UNTIL BACKFLUSH WATER IS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43Â¹ B CHAMBERS FROM THE FOUNDATION STONE ('A' DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) NO COMPACTION REQUIRED. CLEAN 3, 4 LAYER) TO THE 'C' LAYER ABOVE. ISOLATOR ROW SECTION @ CB #1 C. VACUUM STRUCTURE SUMP AS REQUIRED FOUNDATION STONE: FILL BELOW CHAMBERS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43Â¹ PLATE COMPACT OR ROLL TO ACHIEVE A FLAT A FROM THE SUBGRADE UP TO THE FOOT (BOTTOM) DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) 3, 4 SURFACE. Â² Â³ STEP 3) REPLACE ALL COVERS, GRATES, FILTERS, AND LIDS; RECORD OF THE CHAMBER. OBSERVATIONS AND ACTIONS. PLEASE NOTE: 1. THE LISTED AASHTO DESIGNATIONS ARE FOR GRADATIONS ONLY. THE STONE MUST ALSO BE CLEAN, CRUSHED, ANGULAR. FOR EXAMPLE, A SPECIFICATION FOR #4 STONE WOULD STATE: "CLEAN, CRUSHED, STEP 4) INSPECT AND CLEAN BASINS AND MANHOLES UPSTREAM OF THE ANGULAR NO. 4 (AASHTO M43) STONE". 2. STORMTECH COMPACTION REQUIREMENTS ARE MET FOR 'A' LOCATION MATERIALS WHEN PLACED AND COMPACTED IN 9" (230 mm) (MAX) LIFTS USING TWO FULL COVERAGES WITH A VIBRATORY COMPACTOR. STORMTECH SYSTEM. 3. WHERE INFILTRATION SURFACES MAY BE COMPROMISED BY COMPACTION, FOR STANDARD DESIGN LOAD CONDITIONS, A FLAT SURFACE MAY BE ACHIEVED BY RAKING OR DRAGGING WITHOUT COMPACTION EQUIPMENT. FOR SPECIAL LOAD DESIGNS, CONTACT STORMTECH FOR COMPACTION REQUIREMENTS. NOTES ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE ALL PAVEMENT LAYER (DESIGNED 1. INSPECT EVERY 6 MONTHS DURING THE FIRST YEAR OF OPERATION. AROUND CLEAN, CRUSHED, ANGULAR STONE IN A & B LAYERS BY SITE DESIGN ENGINEER) ADJUST THE INSPECTION INTERVAL BASED ON PREVIOUS OBSERVATIONS OF SEDIMENT ACCUMULATION AND HIGH WATER D *TO BOTTOM OF FLEXIBLE PAVEMENT. FOR UNPAVED ELEVATIONS. PERIMETER STONE INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR, (SEE NOTE 6) C INCREASE COVER TO 30" (750 mm). 2. CONDUCT JETTING AND VACTORING ANNUALLY OR WHEN INSPECTION 12" (300 mm) MIN SHOWS THAT MAINTENANCE IS NECESSARY. B EXCAVATION WALL (CAN BE SLOPED OR VERTICAL) 45" (1140 mm) A DEPTH OF STONE TO BE DETERMINED BY DESIGN ENGINEER 9" (230 mm) MIN 6" (150 mm) MIN MC-3500 9" SUBGRADE SOILS 77" (1950 mm) 12" (300 mm) TYP END CAP (230 mm) MIN (SEE NOTE 5) NOTES: 1. MC-3500 CHAMBERS SHALL CONFORM TO THE REQUIREMENTS OF ASTM F2418 "STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 2. MC-3500 CHAMBERS SHALL BE DESIGNED IN ACCORDANCE WITH ASTM F2787 "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 3. "ACCEPTABLE FILL MATERIALS" TABLE ABOVE PROVIDES MATERIAL LOCATIONS, DESCRIPTIONS, GRADATIONS, AND COMPACTION REQUIREMENTS FOR FOUNDATION, EMBEDMENT, AND FILL MATERIALS. 4. THE "SITE DESIGN ENGINEER" REFERS TO THE ENGINEER RESPONSIBLE FOR THE DESIGN AND LAYOUT OF THE STORMTECH CHAMBERS FOR THIS PROJECT. TY. 2 - 54" CB 5. THE SITE DESIGN ENGINEER IS RESPONSIBLE FOR ASSESSING THE BEARING RESISTANCE (ALLOWABLE BEARING CAPACITY) OF THE SUBGRADE SOILS AND THE DEPTH OF FOUNDATION STONE WITH CONSIDERATION FOR THE RANGE OF EXPECTED SOIL MOISTURE CONDITIONS. 6. PERIMETER STONE MUST BE EXTENDED HORIZONTALLY TO THE EXCAVATION WALL FOR BOTH VERTICAL AND SLOPED EXCAVATION WALLS. 7. ONCE LAYER 'C' IS PLACED, ANY SOIL/MATERIAL CAN BE PLACED IN LAYER 'D' UP TO THE FINISHED GRADE. MOST PAVEMENT SUBBASE SOILS CAN BE USED TO REPLACE THE MATERIAL REQUIREMENTS OF LAYER 'C' OR 'D' AT THE SITE DESIGN ENGINEER'S DISCRETION. SHEET 1 OF 1 CB#1 - ISOLATOR ROW BYPASS STORMTECH CHAMBERS C2.3 ORMA F ERRA CB #4 - BAYFILTER TRMT. MH T DESIGN GROUP, INC. INFILTRATION GALLERY 'B' - SECTION INFILTRATION GALLERY 'B' - PLAN VIEW C2.4 GAYTEWAY BUSINESS PARK - BUILDING 'B' SITEWORK ORMA F ERRA T DESIGN GROUP, INC. C1.1 ORMA F ERRA T DESIGN GROUP, INC. C1.2 ORMA F ERRA T DESIGN GROUP, INC. C1.3 ORMA F ERRA T DESIGN GROUP, INC. C1.4 ORMA F ERRA T DESIGN GROUP, INC. C1.5 ORMA F ERRA T DESIGN GROUP, INC. C1.6 ORMA F ERRA T DESIGN GROUP, INC. C1.7 ORMA F ERRA T DESIGN GROUP, INC. C1.8 ORMA F ERRA T DESIGN GROUP, INC. CONCRETE WHEELSTOP ASPHALT PAVING SECTION C2.1 TEMPORARY SWALE ROCK CONSTRUCTION ENTRANCE FILTER FABRIC FENCE CATCH BASIN FILTER ORMA F ERRA T DESIGN GROUP, INC. TEMP. SEDIMENT / INFILTRATION POND ROCK CHECK DAM C2.2 INFILTRATION GALLERY 'A' - PLAN VIEW COVER PIPE CONNECTION TO END CAP WITH ADS INFILTRATION GALLERY 'A' - SECTION GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE MC-3500 CHAMBER INSTALL UNDER ISOLATOR ROW INSPECTION & MAINTENANCE (NORTH ROW) TWO LAYERS OF ADS STEP 1) INSPECT ISOLATOR ROW FOR SEDIMENT GEOSYNTHETICS 315WTM WOVEN A. INSPECTION PORTS (IF PRESENT) GEOTEXTILE BETWEEN FOUNDATION A.1. REMOVE/OPEN LID ON NYLOPLAST INLINE DRAIN STONE AND CHAMBERS. A.2. REMOVE AND CLEAN FLEXSTORM FILTER IF INSTALLED 8.3-FT MIN. WIDTH STRIPS (MC-3500). A.3. USING A FLASHLIGHT AND STADIA ROD, MEASURE DEPTH OF SEDIMENT AND RECORD ON MAINTENANCE LOG A.4. LOWER A CAMERA INTO ISOLATOR ROW FOR VISUAL INSPECTION OF SEDIMENT LEVELS (OPTIONAL) ORMA A.5. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, F PROCEED TO STEP 3. ACCEPTABLE FILL MATERIALS: STORMTECH MC-3500 CHAMBER SYSTEMS B. ALL ISOLATOR ROWS JLM JLM B.1. REMOVE COVER FROM STRUCTURE AT UPSTREAM END OF ISOLATOR AASHTO MATERIAL COMPACTION / DENSITY ROW MATERIAL LOCATION DESCRIPTION B.2. USING A FLASHLIGHT, INSPECT DOWN THE ISOLATOR ROW THROUGH CLASSIFICATIONS REQUIREMENT OUTLET PIPE FINAL FILL: FILL MATERIAL FOR LAYER 'D' STARTS i) MIRRORS ON POLES OR CAMERAS MAY BE USED TO AVOID A FROM THE TOP OF THE 'C' LAYER TO THE BOTTOM ANY SOIL/ROCK MATERIALS, NATIVE SOILS, OR PER PREPARE PER SITE DESIGN ENGINEER'S PLANS. D OF FLEXIBLE PAVEMENT OR UNPAVED FINISHED ENGINEER'S PLANS. CHECK PLANS FOR PAVEMENT N/A PAVED INSTALLATIONS MAY HAVE STRINGENT CONFINED SPACE ENTRY ERRA GRADE ABOVE. NOTE THAT PAVEMENT SUBBASE SUBGRADE REQUIREMENTS. MATERIAL AND PREPARATION REQUIREMENTS. MC-3500 TY. 2 - 54" CB ii) FOLLOW OSHA REGULATIONS FOR CONFINED SPACE ENTRY IF MAY BE PART OF THE 'D' LAYER ENTERING MANHOLE DESIGN GROUP, INC. AASHTO M145Â¹ 24" (600 mm) HDPE ACCESS PIPE T BEGIN COMPACTIONS AFTER 24" (600 mm) OF 11/18/14 B.3. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, A-1, A-2-4, A-3 INITIAL FILL: FILL MATERIAL FOR LAYER 'C' GRANULAR WELL-GRADED SOIL/AGGREGATE MIXTURES, <35% MATERIAL OVER THE CHAMBERS IS REACHED. REQUIRED USE FACTORY PROCEED TO STEP 3. STARTS FROM THE TOP OF THE EMBEDMENT FINES OR PROCESSED AGGREGATE. COMPACT ADDITIONAL LAYERS IN 12" (300 mm) PRE-CORED END CAP OR C STONE ('B' LAYER) TO 24" (600 mm) ABOVE THE MAX LIFTS TO A MIN. 95% PROCTOR DENSITY FOR TOP OF THE CHAMBER. NOTE THAT PAVEMENT MOST PAVEMENT SUBBASE MATERIALS CAN BE USED IN LIEU AASHTO M43Â¹ WELL GRADED MATERIAL AND 95% RELATIVE STANDARD CROSS SECTION PART #: MC3500IEPP24BC STEP 2) CLEAN OUT ISOLATOR ROW USING THE JETVAC PROCESS SUBBASE MAY BE A PART OF THE 'C' LAYER. OF THIS LAYER. 3, 357, 4, 467, 5, 56, 57, 6, 67, 68, 7, 78, 8, 89, DENSITY FOR PROCESSED AGGREGATE A. A FIXED CULVERT CLEANING NOZZLE WITH REAR FACING SPREAD OF 45" MATERIALS. 9, 10 MC-3500 SECTION (1.1 m) OR MORE IS PREFERRED EMBEDMENT STONE: FILL SURROUNDING THE NTS B. APPLY MULTIPLE PASSES OF JETVAC UNTIL BACKFLUSH WATER IS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43Â¹ B CHAMBERS FROM THE FOUNDATION STONE ('A' DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) NO COMPACTION REQUIRED. CLEAN 3, 4 LAYER) TO THE 'C' LAYER ABOVE. ISOLATOR ROW SECTION @ CB #1 C. VACUUM STRUCTURE SUMP AS REQUIRED FOUNDATION STONE: FILL BELOW CHAMBERS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43Â¹ PLATE COMPACT OR ROLL TO ACHIEVE A FLAT A FROM THE SUBGRADE UP TO THE FOOT (BOTTOM) DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) 3, 4 SURFACE. Â² Â³ STEP 3) REPLACE ALL COVERS, GRATES, FILTERS, AND LIDS; RECORD OF THE CHAMBER. OBSERVATIONS AND ACTIONS. PLEASE NOTE: 1. THE LISTED AASHTO DESIGNATIONS ARE FOR GRADATIONS ONLY. THE STONE MUST ALSO BE CLEAN, CRUSHED, ANGULAR. FOR EXAMPLE, A SPECIFICATION FOR #4 STONE WOULD STATE: "CLEAN, CRUSHED, STEP 4) INSPECT AND CLEAN BASINS AND MANHOLES UPSTREAM OF THE ANGULAR NO. 4 (AASHTO M43) STONE". 2. STORMTECH COMPACTION REQUIREMENTS ARE MET FOR 'A' LOCATION MATERIALS WHEN PLACED AND COMPACTED IN 9" (230 mm) (MAX) LIFTS USING TWO FULL COVERAGES WITH A VIBRATORY COMPACTOR. STORMTECH SYSTEM. 3. WHERE INFILTRATION SURFACES MAY BE COMPROMISED BY COMPACTION, FOR STANDARD DESIGN LOAD CONDITIONS, A FLAT SURFACE MAY BE ACHIEVED BY RAKING OR DRAGGING WITHOUT COMPACTION EQUIPMENT. FOR SPECIAL LOAD DESIGNS, CONTACT STORMTECH FOR COMPACTION REQUIREMENTS. NOTES ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE ALL PAVEMENT LAYER (DESIGNED 1. INSPECT EVERY 6 MONTHS DURING THE FIRST YEAR OF OPERATION. AROUND CLEAN, CRUSHED, ANGULAR STONE IN A & B LAYERS BY SITE DESIGN ENGINEER) ADJUST THE INSPECTION INTERVAL BASED ON PREVIOUS OBSERVATIONS OF SEDIMENT ACCUMULATION AND HIGH WATER D *TO BOTTOM OF FLEXIBLE PAVEMENT. FOR UNPAVED ELEVATIONS. PERIMETER STONE INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR, (SEE NOTE 6) C INCREASE COVER TO 30" (750 mm). 2. CONDUCT JETTING AND VACTORING ANNUALLY OR WHEN INSPECTION 12" (300 mm) MIN SHOWS THAT MAINTENANCE IS NECESSARY. B EXCAVATION WALL (CAN BE SLOPED OR VERTICAL) 45" (1140 mm) A DEPTH OF STONE TO BE DETERMINED BY DESIGN ENGINEER 9" (230 mm) MIN 6" (150 mm) MIN MC-3500 9" SUBGRADE SOILS 77" (1950 mm) 12" (300 mm) TYP END CAP (230 mm) MIN (SEE NOTE 5) NOTES: 1. MC-3500 CHAMBERS SHALL CONFORM TO THE REQUIREMENTS OF ASTM F2418 "STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 2. MC-3500 CHAMBERS SHALL BE DESIGNED IN ACCORDANCE WITH ASTM F2787 "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 3. "ACCEPTABLE FILL MATERIALS" TABLE ABOVE PROVIDES MATERIAL LOCATIONS, DESCRIPTIONS, GRADATIONS, AND COMPACTION REQUIREMENTS FOR FOUNDATION, EMBEDMENT, AND FILL MATERIALS. 4. THE "SITE DESIGN ENGINEER" REFERS TO THE ENGINEER RESPONSIBLE FOR THE DESIGN AND LAYOUT OF THE STORMTECH CHAMBERS FOR THIS PROJECT. TY. 2 - 54" CB 5. THE SITE DESIGN ENGINEER IS RESPONSIBLE FOR ASSESSING THE BEARING RESISTANCE (ALLOWABLE BEARING CAPACITY) OF THE SUBGRADE SOILS AND THE DEPTH OF FOUNDATION STONE WITH CONSIDERATION FOR THE RANGE OF EXPECTED SOIL MOISTURE CONDITIONS. 6. PERIMETER STONE MUST BE EXTENDED HORIZONTALLY TO THE EXCAVATION WALL FOR BOTH VERTICAL AND SLOPED EXCAVATION WALLS. 7. ONCE LAYER 'C' IS PLACED, ANY SOIL/MATERIAL CAN BE PLACED IN LAYER 'D' UP TO THE FINISHED GRADE. MOST PAVEMENT SUBBASE SOILS CAN BE USED TO REPLACE THE MATERIAL REQUIREMENTS OF LAYER 'C' OR 'D' AT THE SITE DESIGN ENGINEER'S DISCRETION. SHEET 1 OF 1 CB#1 - ISOLATOR ROW BYPASS STORMTECH CHAMBERS C2.3 ORMA F ERRA CB #4 - BAYFILTER TRMT. MH T DESIGN GROUP, INC. INFILTRATION GALLERY 'B' - SECTION INFILTRATION GALLERY 'B' - PLAN VIEW C2.4 ORMA F ERRA T DESIGN GROUP, INC. C3.1 ORMA F ERRA T DESIGN GROUP, INC. C3.2 ORMA F ERRA T DESIGN GROUP, INC. C3.3 ORMA F ERRA T DESIGN GROUP, INC. C3.4 ORMA F ERRA T DESIGN GROUP, INC. C3.5 ORMA F ERRA T DESIGN GROUP, INC. C3.6 ORMA F ERRA T DESIGN GROUP, INC. C3.7 ORMA F ERRA T DESIGN GROUP, INC. C3.8 ORMA F ERRA T DESIGN GROUP, INC. ORMA F ERRA T DESIGN GROUP, INC. W 12''SS W W W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W W 12''SS P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) 12''SS P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) 12''SS 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W W W 12''SS W 12''SS W W W W SS 12''SS W 12''SS W 12''SS SD W 12''SS W 12''SS W 12''SS GAYTEWAY BUSINESS CENTER - BUILDING 'B' CONTRUCTION PLAN REVIEW & INSPECTION FEE WORKSHEET Community & Economic Development Department City of Arlington 18204 59th Avenue NE Arlington WA 98223 (360) 403-3551 This form is to be completed and submitted with Type I , Type II Type III Construction Permit Application. 1) Based on permit type requested (Type I, Type II or Type III), complete the form as follows: Type I permits complete all sections. Type II permits complete as follows: - Grading Only - Complete Temporary Erosion and Sediment Control (TESC). - Stormwater Drainage Only - Complete the Temporary Erosion and Sediment Control and Stormwater Drainage Section for Public or Private Type III permits complete the Temporary Erosion and Sediment Control (TESC). 2) The developer shall enter the quantities shown on the construction drawings into the Construction Calculation Worksheet. This document is used to determine the amount of plan reivew and inspection fees due to the city. 3) Excel will auto-calculate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should be completed. 4) The summary page calculates the fees due at intake for Civil and Stormwater Drainage construction permits only. This does not include fees for Grading or those required by other departments or agencies. Grading fees are based on Cubic Yard Quantity and shall be calculated at time of permit submittal. Grading fees shall be paid at permit submittal. 5) If an item that is part of your project does not exist in the spreadsheet complete the Write-In-Items section with the item, quantity and associated unit cost. There are a few unit prices that are blank, please complete them accordingly. 6) Inspection fees shall be calculated for Private Development during the review process and shall be paid upon permit issuance. PROJECT COSTS PUBLIC TOTAL PRIVATE TOTAL TOTAL PROJECT COST $ 296,039.50 $ 782,951.25 $ 1,078,990.75 Verify formula, totals do not match PLAN REVIEW & INSPECTION FEES PLAN REVIEW & INSPECTION FEE (6% of Project Value) $ 64,739.45 GRADING FEE (4) (Cubic Yard ) $ - Review fees due at time of submittal Total Review Fees Due $ 64,739.45 An Assurance Device such as a Performance Bond or Assignment of Funds needs to be on file with the City of Arlington prior to permit issuance. The Assurance Device shall be 150% of the Construction Calculation Worksheet which are as follows: Road and Alley (Public) Stormwater Drainage and Grading (Public) Utilities (Public) Temporary Erosion and Sediment Control (Public and Private) ASSURANCE DEVICE Base Calculation of Performance Device $ 296,039.50 PERFORMANCE DEVICE 150% Amount Due $ 444,059.25 Base Calculation of Maintenance Device $ 279,074.50 MAINTENANCE DEVICE 20% Amount Due $ 55,814.90 1 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET TEMPORARY EROSION & SEDIMENT CONTROL Include Public Improvements & Private Development Description Unit Price Unit Quantity Cost Reference # Backfill & compaction-embankment $ 6.50 CY $ - Check dams $ 78.00 EACH 5 $ 390.00 BMP C207 Catch Basin Protection $ 35.50 EACH 4 $ 142.00 Crushed surfacing 1 1/4" minus $ 18.00 TON $ - WSDOT 9-03.9(3) Ditching $ 8.00 CY $ - Excavation-bulk $ 3.00 CY 400 $ 1,200.00 Fence, silt $ 2.00 LF 730 $ 1,460.00 BMP C233 Fence, Temporary (NGPA) $ 2.00 LF $ - Geotextile Fabric $ 2.50 SY $ - Hay Bale Silt Trap $ 0.50 EACH $ - Hydroseeding $ 4,200.00 ACRE $ - BMP C120 Interceptor Swale / Dike $ 1.00 LF 500 $ 500.00 Jute Mesh $ 2.00 SY $ - BMP C122 Level Spreader $ 1.75 LF $ - Mulch, by hand, straw, 3" deep $ 3.00 SY $ - BMP C121 Mulch, by machine, straw, 2" deep $ 1.00 SY $ - BMP C121 Piping, temporary, CPP, 6" $ 12.50 LF $ - Piping, temporary, CPP, 8" $ 19.00 LF $ - Piping, temporary, CPP, 12" $ 24.00 LF $ - Plastic covering, 6mm thick, sandbagged $ 3.00 SY $ - BMP C123 Rip Rap, machine placed; slopes $ 50.00 CY $ - WSDOT 9-13.1(2) Rock Construction Entrance, 50'x15'x1' $ 1,800.00 EACH $ - BMP C105 Rock Construction Entrance, 100'x15'x1' $ 3,600.00 EACH 1 $ 3,600.00 BMP C105 Sediment pond riser assembly $ 3,050.00 EACH $ - BMP C241 Sediment trap, 5' high berm $ 21.00 LF $ - BMP C240 Sed. trap, 5' high, riprapped spillway berm section $ 79.00 LF $ - BMP C240 Seeding, by hand $ 1.00 SY $ - BMP C120 Sodding, 1" deep, level ground $ 8.00 SY $ - BMP C120 Sodding, 1" deep, sloped ground $ 9.50 SY $ - BMP C120 TESC Supervisor $ 84.00 HR 50 $ 4,200.00 Water truck, dust control $ 130.00 HR 16 $ 2,080.00 BMP C140 WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - SUBTOTAL (TESC Only): $ 13,572.00 MOBILIZATION 10%: $ 1,357.20 CONTINGENCY 15%: $ 2,035.80 TOTAL: $ 16,965.00 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET Public Private STORMWATER DRAINAGE Public Improvements Private Development Description Unit Price Unit Quantity Cost Quantity Cost Access Road, Retention / Detention $ 26.00 SY $ - $ - * (CBs include frame and lid) Beehive $ 90.00 EACH $ - $ - CB Type I $ 1,650.00 EACH $ - 16 $ 26,400.00 CB Type IL $ 1,850.00 EACH $ - $ - CB Type II, 48" Dia $ 2,550.00 EACH $ - 1 $ 2,550.00 for additional depth over 4' $ 650.00 FT $ - 1.6 $ 1,040.00 CB Type II, 54" Dia $ 2,700.00 EACH $ - 5 $ 13,500.00 for additional depth over 4' $ 600.00 FT $ - 29.2 $ 17,520.00 CB Type II, 60" Dia $ 2,900.00 EACH $ - $ - for additional depth over 4' $ 750.00 FT $ - $ - CB Type II, 72" Dia $ 4,000.00 EACH $ - $ - for additional depth over 4' $ 900.00 FT $ - $ - Through-curb Inlet Framework (Add) $ 550.00 EACH $ - $ - Cleanout, PVC, 4" $ 200.00 EACH $ - $ - Cleanout, PVC, 6" $ 250.00 EACH $ - 7 $ 1,750.00 Cleanout, PVC, 8" $ 300.00 EACH $ - 3 $ 900.00 Culvert, Box __ ft x __ ft $ - LS $ - $ - Culvert, PVC, 4" $ 12.00 LF $ - 75 $ 900.00 Culvert, PVC, 6" $ 17.00 LF $ - 697 $ 11,849.00 Culvert, PVC, 8" $ 19.00 LF $ - 362 $ 6,878.00 Culvert, PVC, 12" $ 30.00 LF $ - 6 $ 180.00 Culvert, CMP, 8" $ 23.00 LF $ - $ - Culvert, CMP, 12" $ 35.00 LF $ - $ - Culvert, CMP, 15" $ 42.00 LF $ - $ - Culvert, CMP, 18" $ 47.00 LF $ - $ - Culvert, CMP, 24" $ 69.00 LF $ - $ - Culvert, CMP, 30" $ 100.00 LF $ - $ - Culvert, CMP, 36" $ 150.00 LF $ - $ - Culvert, CMP, 48" $ 194.00 LF $ - $ - Culvert, CMP, 60" $ 310.00 LF $ - $ - Culvert, CMP, 72" $ 400.00 LF $ - $ - Culvert, DIP, 8" $ 36.00 LF $ - 111 $ 3,996.00 Culvert, DIP, 12" $ 43.00 LF $ - 106 $ 4,558.00 Culvert, Concrete, 15" $ 52.00 LF $ - $ - Culvert, Concrete, 18" $ 55.00 LF $ - $ - Culvert, Concrete, 24" $ 85.00 LF $ - $ - Culvert, Concrete, 30" $ 136.00 LF $ - $ - Culvert, Concrete, 36" $ 165.00 LF $ - $ - Culvert, Concrete, 42" $ 196.00 LF $ - $ - Culvert, Concrete, 48" $ 210.00 LF $ - $ - Culvert, CPP, 6" $ 16.00 LF $ - $ - Culvert, CPP, 8" $ 22.00 LF $ - 236 $ 5,192.00 Culvert, CPP, 12" $ 28.00 LF $ - 583 $ 16,324.00 Culvert, CPP, 15" $ 34.00 LF $ - $ - Culvert, CPP, 18" $ 39.00 LF $ - $ - Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET Culvert, CPP, 24" $ 49.00 LF $ - $ - Culvert, CPP, 30" $ 62.00 LF $ - $ - Culvert, CPP, 36" $ 69.00 LF $ - $ - Ditching $ 12.00 CY $ - $ - Flow Dispersal Trench (1,436 base+) $ 40.00 LF $ - $ - French Drain (3' depth) $ 39.00 LF $ - $ - Geotextile, laid in trench, polypropylene $ 5.00 SY $ - $ - Infiltration pond testing $ 125.00 HR $ - $ - Mid-tank Access Riser, 48" dia, 6' deep $ 2,025.00 EACH $ - $ - Pipe, High Density Water Pipe (HDWP) $ 160.00 LF $ - $ - Pipe, C900 $ 90.00 LF $ - $ - Pond Overflow Spillway $ 18.00 SY $ - $ - Restrictor/Oil Separator, 12" $ 1,500.00 EACH $ - $ - Restrictor/Oil Separator, 15" $ 1,550.00 EACH $ - $ - Restrictor/Oil Separator, 18" $ 1,680.00 EACH $ - $ - Riprap, placed $ 52.00 CY $ - $ - Tank End Reducer (36" Dia) $ 1,280.00 EACH $ - $ - Thru-Inlet at CB $ 150.00 EACH $ - $ - Trash Rack, 12" $ 320.00 EACH $ - $ - Trash Rack, 15" $ 325.00 EACH $ - $ - Trash Rack, 18" $ 350.00 EACH $ - $ - Trash Rack, 21" $ 375.00 EACH $ - $ - WRITE-IN-ITEMS STORMTECH CHAMBERS $ 800.00 EACH $ - 51 $ 40,800.00 STORMFILTER $ 25,000.00 EACH $ - 1 $ 25,000.00 $ - $ - $ - SUBTOTAL: $ - $ 179,337.00 MOBILIZATION 10%: $ - CONTINGENCY 15%: $ - TOTAL: $ - $ 179,337.00 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET GENERAL ITEMS Public Improvements Private Development Description Unit Price Unit Quantity Cost Quantity Cost Backfill & Compaction- embankment $ 8.00 CY $ - $ - Backfill & Compaction- trench $ 11.00 CY $ - 1841 $ 20,251.00 Clear/Remove Brush, by hand (acre) $ 2,363.00 ACRE $ - $ - Bollards - fixed $ 325.00 EACH $ - 5 $ 1,625.00 Bollards - removable $ 600.00 EACH $ - $ - Clearing/Grubbing/Tree Removal $ 6,000.00 ACRE $ - $ - Excavation - bulk $ 2.50 CY $ - 5117 $ 12,792.50 Excavation - Trench $ 5.00 CY $ - 1841 $ 9,205.00 Fencing, cedar, 6' high $ 25.00 LF $ - $ - Fencing, chain link, 4' $ 19.50 LF $ - $ - Fencing, chain link, vinyl coated, 6' high $ 18.00 LF $ - $ - Fencing, chain link, gate, vinyl coated, 20' $ 1,563.00 EACH $ - $ - Fencing, split rail, 3' high $ 14.00 LF $ - $ - Fill & compact - common barrow $ 27.00 CY $ - 3395 $ 91,665.00 Fill & compact - gravel base $ 30.00 CY $ - $ - Fill & compact - screened topsoil $ 45.00 CY $ - $ - Gabion, 12" deep, stone filled mesh $ 62.00 SY $ - $ - Gabion, 18" deep, stone filled mesh $ 86.00 SY $ - $ - Gabion, 36" deep, stone filled mesh $ 152.00 SY $ - $ - Grading, fine, by hand $ 2.00 SY $ - $ - Grading, fine, with grader $ 1.25 SY $ - $ - Guard Post $ 90.00 EACH $ - $ - Monuments $ 104.00 EACH $ - $ - Sensitive Areas Sign $ 20.00 EACH $ - $ - Sodding, 1" deep, sloped ground $ 10.00 SY $ - $ - Topsoil Type A (imported) $ 30.00 CY $ - $ - Traffic control crew ( 2 flaggers ) $ 98.00 HR 40 $ 3,920.00 $ - Trail, 4" chipped wood $ 9.00 SY $ - $ - Trail, 4" crushed cinder $ 10.00 SY $ - $ - Trail, 4" top course $ 9.50 SY $ - $ - Wall, retaining, concrete $ 66.00 SF $ - $ - Wall, Keystone $ 13.00 SF $ - $ - WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - $ - $ - $ - Subtotal $ 3,920.00 Subtotal $ 135,538.50 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET STREET IMPROVEMENT Public Improvements Private Development Description Unit Price Unit Quantity Cost Quantity Cost AC Grinding, 4' wide machine < 1000sy $ 35.00 SY $ - $ - AC Grinding, 4' wide machine 1000-2000sy$ 8.50 SY $ - $ - AC Grinding, 4' wide machine > 2000sy $ 2.50 SY $ - $ - AC Removal/Disposal/Repair $ 60.00 SY 205 $ 12,300.00 $ - Barricade, Type I $ 36.00 LF $ - $ - Barricade Type II $ 25.00 LF $ - $ - Barricade, Type III ( Permanent ) $ 55.00 LF $ - $ - Conduit, 2" $ 5.00 LF 495 $ 2,475.00 $ - Curb & Gutter, rolled $ 20.00 LF $ - $ - Curb & Gutter, vertical $ 15.00 LF 400 $ 6,000.00 420 $ 6,300.00 Curb and Gutter, demolition and disposal $ 20.00 LF $ - $ - Curb, extruded asphalt $ 5.00 LF $ - $ - Curb, extruded concrete $ 4.50 LF $ - 1663 $ 7,483.50 Guard Rail $ 30.00 LF $ - $ - Sawcut, asphalt, 3" depth $ 3.50 LF 290 $ 1,015.00 $ - Sawcut, concrete, per 1" depth $ 3.00 LF $ - $ - Sealant, asphalt $ 2.00 LF 290 $ 580.00 $ - Shoulder, gravel, 4" thick $ 11.00 SY $ - $ - Sidewalk, 4" thick $ 40.00 SY $ - 338 $ 13,520.00 Sidewalk, 4" thick, demolition and disposal$ 36.00 SY $ - $ - Sidewalk, 6" thick $ 45.00 SY 300 $ 13,500.00 1352 $ 60,840.00 Sidewalk, 6" thick, demolition and disposal$ 45.00 SY 139 $ 6,255.00 $ - Signs $ - LS $ - 1 $ - Sign, Handicap $ 100.00 EACH $ - 4 $ 400.00 Striping, per stall $ 7.50 EACH $ - 69 $ 517.50 Street Light System $ 5,000.00 EACH 1 $ 5,000.00 $ - Traffic Signal $ - LS $ - $ - Traffic Signal Modification $ - LS $ - $ - Striping, thermoplastic, ( for crosswalk ) $ 3.50 SF $ - 30 $ 105.00 Striping, 4" reflectorized line $ 0.40 LF $ - 41 $ 16.40 AC Patching/Trenching Restoration $ 100.00 TON $ - $ - Controlled Density Fill (CDF) $ 90.00 CY $ - $ - WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - $ - $ - $ - Subtotal $ 47,125.00 Subtotal $ 89,182.40 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET STREET SURFACING/PAVEMENT Public Improvements Private Development Description Unit Price Unit Quantity Cost Quantity Cost Asphalt Overlay, 1.5" AC $ 12.00 SY $ - $ - Asphalt Overlay, 2" AC $ 15.00 SY $ - $ - Asphalt Road 2", First 2500 SY $ 10.00 SY $ - 1137 $ 11,370.00 Asphalt Road 2", Qty. over 2500SY $ 9.00 SY $ - $ - Asphalt Road 3", First 2500 SY $ 15.00 SY $ - 2500 $ 37,500.00 Asphalt Road 3", Qty. over 2500 SY $ 13.00 SY $ - 2735 $ 35,555.00 Asphalt Road 5", First 2500 SY $ 22.00 SY $ - $ - Asphalt Road 5", Qty. Over 2500 SY $ 22.00 SY $ - $ - Asphalt Road 6", First 2500 SY $ 25.00 SY $ - $ - Asphalt Road 6", Qty. Over 2500 SY $ 24.00 SY $ - $ - Asphalt Treated Base, 4" thick $ 14.00 SY $ - $ - Gravel Base Course 2" $ 7.50 SY $ - $ - Gravel Base Course 4" $ 15.00 SY $ - 2723 $ 40,845.00 Gravel Base Course 6" $ 22.50 SY $ - 5235 $ 117,787.50 Gravel Road, 4" rock, First 2500 SY $ 15.00 SY $ - $ - Gravel Road, 4" rock, Qty. over 2500 SY $ 11.00 SY $ - $ - Concrete Road, 5", no base, over 2500 SY$ 22.00 SY $ - $ - Concrete Road, 6", no base, over 2500 SY$ 32.00 SY $ - $ - Thickened Edge $ 11.00 LF $ - $ - WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - $ - $ - $ - Subtotal $ - Subtotal $ 243,057.50 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET WATER SYSTEM Public Improvements Private Development Description Unit Price Unit Quantity Cost Quantity Cost Blowoff $ 1,800.00 EACH $ - $ - Connection to Existing Water Main $ 2,000.00 EACH 1 $ 2,000.00 $ - Ductile Iron Watermain, CL 52, 6 Inch Dia $ 65.00 LF 60 $ 3,900.00 $ - Ductile Iron Watermain, CL 52, 8 Inch Dia $ 85.00 LF $ - 105 $ 8,925.00 Ductile Iron Watermain, CL 52, 10 Inch Dia $ 103.00 LF $ - $ - Ductile Iron Watermain, CL 52, 12 Inch Dia. $ 125.00 LF 812 $ 101,500.00 $ - Gate Valve, 6 inch Dia $ 250.00 EACH 2 $ 500.00 $ - Gate Valve, 8 Inch Dia $ 380.00 EACH $ - 1 $ 380.00 Gate Valve, 10 Inch Dia $ 425.00 EACH $ - $ - Gate Valve, 12 Inch Dia $ 500.00 EACH 4 $ 2,000.00 $ - Fire Hydrant Assembly, with Guard Posts $ 3,000.00 EACH 2 $ 6,000.00 $ - Fire Hydrant Assembly, without Guard Posts $ 2,500.00 EACH $ - $ - Air-Vac, 8 Inch Dia $ 6,000.00 EACH $ - $ - Air-Vac,10 Inch Dia $ 7,500.00 EACH $ - $ - Air-Vac, 12 Inch Dia $ 12,000.00 EACH $ - $ - Pressure Reducing Valve Assembly, 8 In. Dia $ 3,800.00 EACH $ - $ - Pressure Reducing Valve Assembly, 10 In. Dia$ 4,200.00 EACH $ - $ - Pressure Reducing Valve Assembly, 12 In. Dia$ 5,000.00 EACH $ - $ - Valve Marker Post $ 350.00 EACH $ - $ - WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - $ - $ - Subtotal $ 115,900.00 Subtotal $ 9,305.00 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET SANITARY SEWER Public Improvements Private Development Description Unit Price Unit Quantity Cost Quantity Cost Connection to Existing Sewer Main $ 10,000.00 EACH $ - $ - Clean Outs $ 500.00 EACH $ - 1 $ 500.00 Grease Interceptor, 500 gallon $ 6,000.00 EACH $ - $ - Grease Interceptor, 1000 gallon $ 10,000.00 EACH $ - $ - Grease Interceptor, 1500 gallon $ 15,000.00 EACH $ - $ - Side Sewer Pipe, PVC. 4 Inch Dia $ 8.00 LF $ - $ - Side Sewer Pipe, PVC. 6 Inch Dia $ 12.00 LF $ - 15 $ 180.00 Sewer Pipe, PVC, 8 inch Dia $ 33.00 LF 314 $ 10,362.00 $ - Sewer Pipe, PVC, 12 Inch Dia $ 41.00 LF $ - $ - Sewer Pipe, PVC, ____ Inch Dia $ - LF $ - $ - Lift Station (Entire System) $ - LS $ - $ - Manhole, 48 Inch Dia $ 3,000.00 EACH 1 $ 3,000.00 1 $ 3,000.00 for additional depth over 4 feet/per foot$ 532.00 FEET 5.55 $ 2,952.60 4 $ 2,128.00 Manhole, 54 Inch Dia $ 3,500.00 EACH $ - $ - for additional depth over 4 feet/per foot$ 532.00 FEET $ - $ - Manhole, 60 Inch Dia $ 3,700.00 EACH $ - $ - for additional depth over 4 feet/per foot$ 532.00 FEET $ - $ - Manhole, 72 Inch Dia $ 4,000.00 EACH $ - $ - for additional depth over 4 feet/per foot$ 625.00 FEET $ - $ - Manhole, 96 Inch Dia $ 5,000.00 EACH $ - $ - for additional depth over 4 feet/per foot$ 625.00 FEET $ - $ - Outside Drop $ - LS $ - $ - Inside Drop $ - LS $ - $ - Pipe, C-900 $ 90.00 LF $ - $ - Pipe, High Density Water Pipe (HDWP) $ 160.00 LF $ - $ - WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - $ - $ - $ - Subtotal $ 16,314.60 Subtotal $ 5,808.00 Rev 7/2017 CONSTRUCTION CALCULATION WORKSHEET LANDSCAPING & VEGETATION Include Public Improvements & Private Development Description Unit Price Unit Quantity Cost Street Trees $ 500.00 EACH $ - Root Barrier EACH $ - Median Landscaping $ - LS $ - Right-of-Way Landscaping $ - LS $ - Wetland Landscaping $ - LS $ - Private Landscaping $ 40,000.00 LS 1 $ 40,000.00 WRITE-IN-ITEMS $ - $ - $ - $ - $ - $ - Subtotal $ 40,000.00 (INCLUDES GENERAL, STREET, SURFACING, WATER, PUBLIC PRIVATE SEWER, LANDSCAPING) SUBTOTAL $ 223,259.60 $ 482,891.40 MOBILIZATION 10%: $ 22,325.96 $ 48,289.14 CONTINGENCY 15%: $ 33,488.94 $ 72,433.71 GRANDTOTAL: $ 279,074.50 $ 603,614.25 Rev 7/2017 SEPA ENVIRONMENTAL CHECKLIST Purpose of checklist: Governmental agencies use this checklist to help determine whether the environmental impacts of your proposal are significant. This information is also helpful to determine if available avoidance, minimization or compensatory mitigation measures will address the probable significant impacts or if an environmental impact statement will be prepared to further analyze the proposal. Instructions for applicants: This environmental checklist asks you to describe some basic information about your proposal. Please answer each question accurately and carefully, to the best of your knowledge. You may need to consult with an agency specialist or private consultant for some questions. You may use â€œnot applicableâ€ or "does not apply" only when you can explain why it does not apply and not when the answer is unknown. You may also attach or incorporate by reference additional studies reports. Complete and accurate answers to these questions often avoid delays with the SEPA process as well as later in the decision-making process. The checklist questions apply to all parts of your proposal, even if you plan to do them over a period of time or on different parcels of land. Attach any additional information that will help describe your proposal or its environmental effects. The agency to which you submit this checklist may ask you to explain your answers or provide additional information reasonably related to determining if there may be significant adverse impact. Instructions for Lead Agencies: Please adjust the format of this template as needed. Additional information may be necessary to evaluate the existing environment, all interrelated aspects of the proposal and an analysis of adverse impacts. The checklist is considered the first but not necessarily the only source of information needed to make an adequate threshold determination. Once a threshold determination is made, the lead agency is responsible for the completeness and accuracy of the checklist and other supporting documents. Use of checklist for nonproject proposals: For nonproject proposals (such as ordinances, regulations, plans and programs), complete the applicable parts of sections A and B plus the SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (part D). Please completely answer all questions that apply and note that the words "project," "applicant," and "property or site" should be read as "proposal," "proponent," and "affected geographic area," respectively. The lead agency may exclude (for non- projects) questions in Part B - Environmental Elements â€“that do not contribute meaningfully to the analysis of the proposal. A. Background [HELP] 1. Name of proposed project, if applicable: Gayteway Business Park â€“ Building â€˜Bâ€™ 2. Name of applicant: Gayteway, LLC 3. Address and phone number of applicant and contact person: 845 106th Avenue NE #102, Bellevue, WA 98004. Attn: Chris Gayte, phone: (206) 240-9739 4. Date checklist prepared: March 5, 2019 SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 1 of 10 5. Agency requesting checklist: City of Arlington 6. Proposed timing or schedule (including phasing, if applicable): Construction: May 2019, Completion Dec. 2019. 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. Building â€˜Câ€™ to the south. Future development east of Northern Pacific Railroad (same property). 8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. None 9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. None known. 10. List any government approvals or permits that will be needed for your proposal, if known. Site Plan Review approval, SEPA review, building permits. 11. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project description.) Proposed 63,691 sf building with warehouse and office use. 12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. Located at 20015 67th Avenue NE, Arlington, 98223. NW1/4 & SW1/4 of Section 14, T31N, R5E, W.M. B. Environmental Elements [HELP] 1. Earth [help] a. General description of the site: Flat (circle one): Flat, rolling, hilly, steep slopes, mountainous, other _____________ b. What is the steepest slope on the site (approximate percent slope)? 50% for a small area. Predominately flat. c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any agricultural land of long-term commercial significance and whether the proposal results in removing any of these soils. SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 2 of 10 The site includes land cover of asphalt and crushed rock. Areas of wood fill exist to depths of 2 to 8 feet; this material must be overexcavated. Site generally underlain by recessional outwash to the explored depths of 9 to 20 feet. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. None known. e. Describe the purpose, type, total area, and approximate quantities and total affected area of any filling, excavation, and grading proposed. Indicate source of fill. 5117 bcy of excavation, 3395 bcy of fill within the proposed 3.8 ac work area. Disposal site not determined at this time. f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. No if erosion control measures are implemented. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? 90% within the proposed work area. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: Implement erosion and sediment control measures. 2. Air [help] a. What types of emissions to the air would result from the proposal during construction, operation, and maintenance when the project is completed? If any, generally describe and give approximate quantities if known. Minor discharges from warehouse use. Minor air emission from small distilling use. b. Are there any off-site sources of emissions or odor that may affect your proposal? If so, generally describe. No c. Proposed measures to reduce or control emissions or other impacts to air, if any: None. 3. Water [help] a. Surface Water: [help] 1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. No. 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. No 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. None SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 3 of 10 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known. No 5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. No 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. No b. Ground Water: [help] 1) Will groundwater be withdrawn from a well for drinking water or other purposes? If so, give a general description of the well, proposed uses and approximate quantities withdrawn from the well. Will water be discharged to groundwater? Give general description, purpose, and approximate quantities if known. No 2) Describe waste material that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage; industrial, containing the following chemicals. . . ; agricultural; etc.). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. None c. Water runoff (including stormwater): 1) Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. Surface water from the development will discharge to an infiltration gallery. 2) Could waste materials enter ground or surface waters? If so, generally describe. Runoff treatment will be proposed to prevent pollutants from being discharged underground. 3) Does the proposal alter or otherwise affect drainage patterns in the vicinity of the site? If so, describe. No d. Proposed measures to reduce or control surface, ground, and runoff water, and drainage pattern impacts, if any: The proposed storm infiltration system will eliminate runoff discharges to the public storm system. 4. Plants [help] a. Check the types of vegetation found on the site: ____deciduous tree: alder, maple, aspen, other _ X _evergreen tree: fir, cedar, pine, other SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 4 of 10 ____shrubs _X__grass ____pasture ____crop or grain ____ Orchards, vineyards or other permanent crops. ____ wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other ____water plants: water lily, eelgrass, milfoil, other ____other types of vegetation b. What kind and amount of vegetation will be removed or altered? Minor grass and shrub removal. Site is almost entirely pavement and gravel. c. List threatened and endangered species known to be on or near the site. None known. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: New perimeter and parking lot landscaping will be proposed to meet City requirements. e. List all noxious weeds and invasive species known to be on or near the site. None known. 5. Animals [help] a. List any birds and other animals which have been observed on or near the site or are known to be on or near the site. None observed or known. Examples include: birds: hawk, heron, eagle, songbirds, other: mammals: deer, bear, elk, beaver, other: fish: bass, salmon, trout, herring, shellfish, other ________ b. List any threatened and endangered species known to be on or near the site. None known. c. Is the site part of a migration route? If so, explain. No d. Proposed measures to preserve or enhance wildlife, if any: None. e. List any invasive animal species known to be on or near the site. None known. 6. Energy and Natural Resources [help] a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Electric and Natural Gas. SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 5 of 10 b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: None 7. Environmental Health [help] a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. No 1) Describe any known or possible contamination at the site from present or past uses. None 2) Describe existing hazardous chemicals/conditions that might affect project development and design. This includes underground hazardous liquid and gas transmission pipelines located within the project area and in the vicinity. None known. 3) Describe any toxic or hazardous chemicals that might be stored, used, or produced during the project's development or construction, or at any time during the operating life of the project. No toxic or hazardous material is expected to be produced during the buildingâ€™s operating life. Minor use of toxic or hazardous materials during construction. 4) Describe special emergency services that might be required. None 5) Proposed measures to reduce or control environmental health hazards, if any: None b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? None 2) What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indi- cate what hours noise would come from the site. Noise generation will be minor associated with warehouse and office use. 3) Proposed measures to reduce or control noise impacts, if any: None 8. Land and Shoreline Use [help] a. What is the current use of the site and adjacent properties? Will the proposal affect current land uses on nearby or adjacent properties? If so, describe. Site is currently vacant and recently cleared of all structures. SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 6 of 10 b. Has the project site been used as working farmlands or working forest lands? If so, describe. How much agricultural or forest land of long-term commercial significance will be converted to other uses as a result of the proposal, if any? If resource lands have not been designated, how many acres in farmland or forest land tax status will be converted to nonfarm or nonforest use? No 1) Will the proposal affect or be affected by surrounding working farm or forest land normal business operations, such as oversize equipment access, the application of pesticides, tilling, and harvesting? If so, how: No c. Describe any structures on the site. All existing structures have been removed. d. Will any structures be demolished? If so, what? All existing structures have been removed. e. What is the current zoning classification of the site? GI â€“ General Industrial f. What is the current comprehensive plan designation of the site? Industrial g. If applicable, what is the current shoreline master program designation of the site? Not Applicable. h. Has any part of the site been classified as a critical area by the city or county? If so, specify. No i. Approximately how many people would reside or work in the completed project? 50 people j. Approximately how many people would the completed project displace? None k. Proposed measures to avoid or reduce displacement impacts, if any: None L. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: None m. Proposed measures to reduce or control impacts to agricultural and forest lands of long-term commercial significance, if any: None 9. Housing [help] a. Approximately how many units would be provided, if any? Indicate whether high, mid- dle, or low-income housing. Zero b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing. None c. Proposed measures to reduce or control housing impacts, if any: None SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 7 of 10 10. Aesthetics [help] a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? 32 feet b. What views in the immediate vicinity would be altered or obstructed? None c. Proposed measures to reduce or control aesthetic impacts, if any: None 11. Light and Glare [help] a. What type of light or glare will the proposal produce? What time of day would it mainly occur? Typical lighting associated with a warehouse / office use. b. Could light or glare from the finished project be a safety hazard or interfere with views? No c. What existing off-site sources of light or glare may affect your proposal? None d. Proposed measures to reduce or control light and glare impacts, if any: Lights to be shielded to limit offsite glare. 12. Recreation [help] a. What designated and informal recreational opportunities are in the immediate vicinity? None b. Would the proposed project displace any existing recreational uses? If so, describe. No c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: None 13. Historic and cultural preservation [help] a. Are there any buildings, structures, or sites, located on or near the site that are over 45 years old listed in or eligible for listing in national, state, or local preservation registers ? If so, specifically describe. No b. Are there any landmarks, features, or other evidence of Indian or historic use or occupation? This may include human burials or old cemeteries. Are there any material evidence, artifacts, or areas of cultural importance on or near the site? Please list any professional studies conducted at the site to identify such resources. No c. Describe the methods used to assess the potential impacts to cultural and historic resources on or near the project site. Examples include consultation with tribes and the department of archeology and historic preservation, archaeological surveys, historic maps, GIS data, etc. Review with owner. SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 8 of 10 d. Proposed measures to avoid, minimize, or compensate for loss, changes to, and disturbance to resources. Please include plans for the above and any permits that may be required. None 14. Transportation [help] a. Identify public streets and highways serving the site or affected geographic area and describe proposed access to the existing street system. Show on site plans, if any. Site has frontage along 67th Avenue NE. b. Is the site or affected geographic area currently served by public transit? If so, generally describe. If not, what is the approximate distance to the nearest transit stop? No bus transite along site frontage. Bus route 220/230 approximately 1100 feet north along 204th Street NE. c. How many additional parking spaces would the completed project or non-project proposal have? How many would the project or proposal eliminate? 69 stalls proposed. Zero eliminated. d. Will the proposal require any new or improvements to existing roads, streets, pedestrian, bicycle or state transportation facilities, not including driveways? If so, generally describe (indicate whether public or private). Project will involve minor driveway improvements. e. Will the project or proposal use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. No f. How many vehicular trips per day would be generated by the completed project or proposal? If known, indicate when peak volumes would occur and what percentage of the volume would be trucks (such as commercial and nonpassenger vehicles). What data or transportation models were used to make these estimates? g. Will the proposal interfere with, affect or be affected by the movement of agricultural and forest products on roads or streets in the area? If so, generally describe. No h. Proposed measures to reduce or control transportation impacts, if any: None 15. Public Services [help] a. Would the project result in an increased need for public services (for example: fire protection, police protection, public transit, health care, schools, other)? If so, generally describe. Minor increase in public services. b. Proposed measures to reduce or control direct impacts on public services, if any. None SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 9 of 10 16. Utilities [help] a. Circle utilities currently available at the site: electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic system, other ___________ d. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. Water: City of Arlington Sewer: City of Arlington Electric: Snohomish County PUD Gas: Cascade Natural Gas Telephone: Century Link Refuse: Waste Management C. Signature [HELP] The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relying on them to make its decision. Signature: ___________________________________________________ Name of signee __________________________________________________Daniel B. Taylor, Architect AIA Position and Agency/Organization ____________________________________Ownership Representative, Gayteway Business Park LLC Date Submitted: _____________APRIL 10, 2019 SEPA Environmental checklist (WAC 197-11-960) July 2016 Page 10 of 10 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1.1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 1. NEH Easement City needs copy of temporary construction easement The Developer is still trying to contact the with adjacent property prior to construction property owner to the north. We have prepared a temporary easement description to accommodate the proposed work. 2. NEH SWPPP Need physical copy of SWPPP for file See attached Ecology Construction Stormwater General Permit (WAR307838). 3. NEH Traffic Traffic report body missing, appendix only See attached reissued Traffic Report. 4. NEH Plan set Remove as-built signature block Done 5. NEH Cover Cover signature block needs to be the larger block Done 6. NEH C1.4 Building submittal and approval required for wall Note added on C1.2 & C1.4 that a building design and engineering prior to civil approval. permit will be required for the reconstructed north wall. Our geotech engineering is working on the permit docs for this wall. 7. NEH C1.4 Change wall note on plan â€“ see approved building Iâ€™ve noted that a separate building permit is permit required. 8. NEH Plan set Plans will be sufficient for a grading permit once area Iâ€™ve revised the earthwork quantities on Sheet of unsuitable materials excavation, estimated quantity C1.1. Volumes reflect the overexcavation of of removal, and design fill material unsuitable fill and backfill with structural fill. 9. NEH Plan set Signage of vehicle restriction (size) needed at the The north driveway is designed for a WB-62 northern driveway vehicle which is the max vehicle for this development. A note was added to reflect the sign to be installed by Bldg C which prohibits truck traffic between Bldg B & C. 10. NEH Drainage Report references Snohomish County drainage Corrected. See updated storm report. Report manual instead of SWMMWW 11. NEH Drainage Page 7 & Both say project triggers enhanced treatment Corrected. See updated storm report. Report 10 12. NEH Drainage MR 5 Include T5.13 Corrected. See updated storm report. Report Page 1 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1.1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 13. NEH Drainage MR 6 Expand discussion of level of treatment required and Corrected. See updated storm report. Report how met sizing of treatment, number/size of storm filters used, treatment flow rate. 14. NEH Drainage Show infiltration facility drains within required time Corrected. See updated storm report. Report 15. NEH Drainage Discuss if pre-treatment is needed and how (catch in Corrected. See updated storm report. Report CB's, Oil/Water Separators in CB) 16. NEH Drainage Page 10 States enhanced treatment is required, but only basic Corrected. See updated storm report. Report is provided 17. NEH Drainage MR 7 Expand discussion for Flow Control, include required Corrected. See updated storm report. Report size, depth, volume, # of chambers, etc.) 18. LP Grading Construction general permit needed prior to any land See Item 2 above. disturbing activity 19. GS Water Sheet C1.6 COA Std.4-1.18 Fire Hydrants: W-8 & W-6: Revised. See Sht. C1.6. As drawn, Hydrant spacing exceeds the 300' Max. 20. GS Water Sheet C1.6 COA Std.4-1.03 Water Mains: Revised. See Sht. C1.6. At W-6 extend 12" DI North to Lot #3. Use an additional 12" FL Tee and (2) 12" FL x MJ G.V. (North & West) (1) FL x MJ Adapter (South) in place of the (2) 45 bends. 21. GS Water Sheet C1.6 Blow Off Assembly Per COA Std. Detail W-180 Revised. See Sht. C1.6. 22. GS Water Sheet C1.6 W14, W16 & W18 Include "New 2" Water Service Per Revised. See Sht. C1.6. COA Std. Detail W-050" 23. GS Water Sheet C1.7 The question of coverage on the Storm Crossings. Note was added but based on the storm depths I Approximately Sta. # 31+60 (+-) & between Sta. # donâ€™t see how I can make it work with water 35+00 & Sta. # 36+00. over storm at the lesser 6â€ clearance. For now I still show water bends under the storm crossings. Page 2 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1.1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved COA will allow 6" min. between bottom of 12" DI Water Main and top of Storm with a minimum 30" of Cover over the 12" DI. CDF is required in these areas for support. 24. FR Sewer Sheet C1.3 Temp sediment pond appears to conflict with sewer Iâ€™ve added a note for the sewer main to be installed under the sediment pond. Noted as well in the construction sequence on Sheet C3.8. 25. FR Sewer Sheet C1.3 Note in middle of page referring to existing utilities General note removed. New demo notes added structures removed/abandoned. All utilities should be for specific utilities. identified so that proper procedures are taken to abandon or remove. 26. FR Sewer Sheet C1.3 Is there a construction sequence to review as to Construction sequence added on Sheet C3.8. answer the questions above? Page 3 of 3 T ERRA F ORMA DES I GN GROUP STORM DRAINAGE REPORT _______________________________________________________________________ GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ LOCATION: 20015 67TH AVENUE NE ARLINGTON, WA 98223 ISSUE DATE: June 12, 2019 PREPARED FOR: GAYTEWAY, LLC Contact: Chris Gayte Phone: (206) 240-9739 6/12/19 C I V I L E N G I N E E R I N G & L A N D S C A P E A R C H I T E C T U R E 5027 51st Avenue SW Seattle WA 98136 phone 206.923.0590 website www.terraformadesigngroup.com GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ TABLE OF CONTENTS 1. PROJECT OVERVIEW & MAPS 1 2. EXISTING CONDITIONS SUMMARY 3 3. OFF-SITE ANALYSIS REPORT 6 4. SUMMARY OF MINIMUM REQUIREMENTS 6 5. PERMANENT STORMWATER CONTROL PLAN 10 6. CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN 17 7. SPECIAL REPORTS & STUDIES 17 8. OTHER PERMITS 17 9. OPERATION MAINTENANCE MANUAL, SOURCE CONTROL 17 10. BOND QUANTITIES WORKSHEET 17 APPENDIX A â€“ WWHM CALCULATIONS APPENDIX B â€“ INFILTRATION STUDY AND GEOTECHNICAL REPORT APPENDIX C â€“ STORM OPERATION & MAINTENANCE MANUAL APPENDIX D - CIVIL DESIGN GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 1 - PROJECT OVERVIEW AND MAPS This Storm Drainage Report for the Gayteway Business Park â€“ Building â€˜Bâ€™ has been submitted to the City of Arlington as part of our Civil Permit submittal. Project Proponent: Gayteway, LLC Property Area: 3.52 acres (Lot 2 of proposed BLA) Total Parcel Area: 54 acres Site Location: 20015 67th Avenue NE, Arlington, WA 98223 NW Â¼ & SW Â¼ of SE1/4 of SEC. 14, T31N, R5E, City of Arlington, Snohomish County Parcel ID: 31051400200700 Required Permits: SEPA, Grading Permit, Building Permit The proposed development consists of a new office / warehouse / manufacturing building located at 20015 67th Avenue NE. The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 (west side of railroad tracks) and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The proposed adjacent Building â€˜Câ€™ development has already been submitted to the City for permit. Work includes the proposed site clearing, grading, paving, structures, drainage, utilities, road improvements and landscaping. The existing property was previously used for lumber operations and has since be vacated and structures cleared. The project will require drainage review from the City of Arlington and compliance with the 2014 Washington State Department of Ecology Surface Water Management Manual for Western Washington. Since the development includes greater than 5000 sf of New Impervious Surface, all 10 Min. Technical Requirements apply. Onsite drainage improvements includes new catch basins and storm drainage for surface runoff. Stormwater infiltration will be proposed for the proposed parking, landscaping and roof drainage runoff; underground infiltration chambers are proposed at this time. Basic Runoff Treatment will be provided for the pavement areas via a Bayfilter treatment system prior to discharge to infiltration galleries. A separate drainage report will be prepared for the Building â€˜Câ€™ development to the south. The developer intends to building both buildings and sites concurrently. Page 1 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ 20015 67th Avenue NE, Arlington, WA 98223 NW Â¼ & SW Â¼ of SE1/4 of SEC. 14, T31N, R5E, City of Arlington, Snohomish County Page 2 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 2 - EXISTING CONDITIONS SUMMARY The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The existing property was previously used for lumber operations and has since be vacated and structures cleared. The site is predomimately exposed soil. The property slopes slightly to the north at an average gradient of 1.5 percent. There are several catch basins and storm drains which collect runoff. Drainage is discharged to an existing infiltration pond within Lot 3 at the northeast corner of the property. The pond may be removed with the future Building B development. The site receives minimal drainage from adjacent properties. The property is not within the 100-yr floodplain. We do not know of any onsite or nearby wetlands or sensitive areas. Portage Creek is approximately one-half mile downstream to the northwest. The existing soils are classified as Everett Very Gravelly Sany Loam, 0- to 8 percent slopes according to the National Cooperative Soil Survey by the USDA Natural Resources Conservation Service. These soils are generally consist of very gravelly sandy loam. Depth to densic material is is greater than 80 inches depth. The soils belong to Hydraulic Soil Group â€˜Aâ€™. A Soil Infiltration Rate study was prepared by Sondergaard Geoscience, PLLC, dated April 24, 2018 (Revised April 9, 2019). Twelve exploration pits we done over the 8.3 acre portion west of the railroad tracks. Existing soils generally consisted of crushed rock fill over some pockets of wood fill over Recessional Outwash. The outwash material was encountered to depths of 9 to 14 feet below grade and consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. Groundwater seepage was not encountered with the exception of pit EP-9 (at 6.5-ft depth near the NE corner of the 8.3 acre property). Infiltration rates were measured using grain size analyses at six (6) planned infiltration locations. Rates varied from 38 to 568 in/hr with test depths of 7 to 9 feet. The geotechnical engineer noted an average uncorrected soil infiltration rate of 85 in/hr. Correction factors were applied to determined a design infiltration rate as follows: Correction Factor: CFv = 0.8, CFt = 0.4, Cfm = 0.9 Combined Factor= 0.36 (per Ecology SWMMWW, Vol III, Sec. 3.3.6(3) Design Infilt. Rate: 24.5 in/hr ** Note: a design infiltration rate of 13.7 in/hr will be used. See Appendix B for the infiltration study and geotechnical report. Page 3 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ EXISTING SITE AERIAL & SOIL IDENTIFIER Page 4 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SNOHOMISH COUNTY PARCEL MAP Depicts Entire 54 acre Parcel Page 5 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 3 - OFFSITE ANALYSIS REPORT The property slopes slightly to the north at an average gradient of 1.5 percent. The site receives minimal drainage from adjacent properties. The onsite drainage discharges to an existing infiltration pond at the northeast corner of the Lot 3 to the north. Drainage within 67th Avenue NE continues northward and likely outfalls to Portage Creek approximately one-half mile downstream. We do not know of any drainage problems associated with the downstream system. SECTION 4 - SUMMARY OF MINUMUM REQUIREMENTS 10 Minimum Technical Requirements as provided within Vol. 1, Section 2 of the DOE Manual: Minimum Requirement #1 â€“ Stormwater Site Plan This Storm Drainage Report and the Civil Plans address the temporary and permanent drainage impacts of the project. Minimum Requirement #2 â€“ Construction Stormwater Pollution Prevention Plan An Erosion Control Plan and Construction Stormwater Pollution Prevention Plan (CSWPPP) will be prepared for the contractor. A Department of Ecology Construction Stormwater Permit has been obtained (WAR307838). Minimum Requirement #3 - Source Control of Pollution The proposed business park site is a relatively low pollution generator. General source control pollution prevention plans and a storm operation and maintenance manual with the final permit submittal. Minimum Requirement #4 â€“ Preservation of Natural Drainage Systems and Outfalls Onsite drainage will continue to be retained onsite. Minimum Requirement #5 â€“ On-Site Stormwater Management As required by the 2014 SWMMWW, On-Site Stormwater Management is required where feasible based on site conditions. Infiltration vaults will be proposed to retain on development runoff. We expect to meet the LID Duration standard such that no further Stormwater Management practices will be required. BMP T5.13 â€“ Post Construction Soil Quality and Depth will be required for all disturbed area that will remain pervious. See plan detail 4/C2.4. Page 6 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Minimum Requirement #6 â€“ Runoff Treatment The proposed business park will trigger Runoff Treatment for all pollution generating surfaces. We conclude that â€˜Basic Treatmentâ€™ is applicable to our project; Enhanced Treatment was not triggered based on the following information below: Page 770 of 2014 SWMMWW: Except where specified under Step 6, Enhanced Treatment for reduction in dissolved metals is required for the following project sites that: 1) discharge directly to fresh watersor conveyance systems tributary to fresh waters designated for aquatic life use or that have an existing aquatic life use ** No, Gayteway infiltrates runoff 100%**; or 2) use infiltration strictly for flow control â€“ not treatment â€“ and the discharge is within Â¼ mile of a fresh water designated for aquatic life use or that has an existing aquatic life use **No, our facility is > Â¼ mi from Portage Creek** Basic Treatment will be provided for the pollution generating surfaces via Bayfilter treatment cartridges prior to discharge to the infiltration chamber gallery. Calculations for the treatment system are provided on Page 15 of this report. Two (2) Bayfilter â€˜545â€™ cartridges are proposed within an 72-in diameter manhole. The manhole will be located near the NW driveway. The roof runoff will bypass the treatment system. The Bayfilter system will be constructed upstream of the infiltration gallery, thereby provided Pretreatment prior to the infiltration facility. Note: runoff flows up to the Water Quality Flowrate are discharged to the Isolator Row of the Stormtech system. This Isolator Row is wrapped with geotextile to capture solids within this void in order to protect the rock gallery from siltation. Larger event flows will have the opportunity to overflow into the Isolator Row Bypass and enter into the remaining portion of the system. Minimum Requirement #7 â€“ Flow Control Infiltration chambers are proposed to retain all development runoff. Two (2) infiltration galleries have been design to accommodate the onsite roof, pavement and landscape areas. Gallery â€œAâ€ is located at the NW corner of the site and is designed for the site pavement and landscape areas and a portion of the roof runoff. Total tributary area of 2.68 acres. 39 ~ MC-3500 Stormtech chambers are proposed. Design storage depth is 5.5-ft with the bottom of gallery at approximately 12 feet below grade. Available storage volume = 6898 cf. Gallery â€œBâ€ is located at the NE corner of the site and is designed for the eastern portion of the building roof area. Total tributary area of 0.62 acres. 12 ~ MC-3500 Stormtech chambers are proposed. Design storage depth is 5.5-ft with the bottom of gallery at approximately 8 feet below grade. Available storage volume = 2123 cf. Using the Western Washington Hydrology Method, each facility retains 100% of all storm events (no offsite discharge). See Section 5 of this report for additional information. Page 7 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Minimum Requirement #8 â€“ Wetlands Protection There are no wetlands within the proposed development area or immediate vicinity. Minimum Requirement #9 - Basin / Watershed Planning We do not know of any local basin or watershed planning. Minimum Requirement #10 â€“ Operation and Maintenance A Stormwater Operation Maintenance Manual and site Source Control measures are included. Page 8 Page 9 Page 10 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 5 - PERMANENT STORMWATER CONTROL PLAN The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The proposed Building â€œBâ€ development will include approximately 3.20 acres of impervious area of the 3.52 acre Lot 2 parcel. Runoff Flow Control will be required. Underground infiltration chambers by Stormtech are proposed to retain all development runoff. Infiltration Gallery â€˜Aâ€™ is proposed at the northwest corner of the site to service all pavement areas, landscape areas and the west side of the building roof. Infiltration Gallery â€˜Bâ€™ is located at the northeast corner of the building and designed to serve the east side of the building roof (0.62 acres). Runoff will infiltrate into the native Everett Very Gravelly Sandy Loam soils, with an expected Design Infiltration Rate of 13.7 in/hr. At this time, the bottom of the infiltration gallery is approximately 11 to 13 feet below existing and proposed grades. We are confident that the existing subsoils are consistent with the sample soils at 7 foot depth. Additional infiltration tests will be peformed at the start of site construction. See attached basin data and infiltration system summary. Sizing calculations were provided via the Western Washington Hydrologic Method (WWHM) within computer output provided within Appendix A. The proposed drawdown time of each facility is accounted for by using the continuous modeling inherent with WWHM. We will meet LID Duration Control to meet the intent of onsite Stormwater Management requirements as a result of our onsite underground infiltration galleries. The development will trigger Basic Treatment for all pollution generating surfaces. Bayfilter treatment cartridges are proposed for runoff treatment of the pollution generating pervious and impervious surfaces prior to discharge to the infiltration gallery. Calculations for the treatment system are provided on Page 15 of this report. Two (2) Bayfilter â€˜545â€™ cartridges are proposed within an 72-in diameter manhole. The manhole will be located near the NW driveway. The Bayfilter system will be constructed upstream of the infiltration gallery, thereby provided Pretreatment prior to the infiltration facility. Note: runoff flows up to the Water Quality Flowrate are discharged to the Isolator Row of the Stormtech system. This Isolator Row is wrapped with geotextile to capture solids within this void in order to protect the rock gallery from siltation. Larger event flows will have the opportunity to overflow into the Isolator Row Bypass and enter into the remaining portion of the system. Page 11 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ STORMWATER DATA - BASIN 'A' Project Name: GAYTEWAY - BULDING 'B' By: P.A.D. Project Number: 18005 Date: 3/4/19 DRAINAGE CRITERIA: CITY OF ARLINGTON RAINFALL METHOD: WWHM Step 1) Site Data 1) General characteristics: Basin A Soil type outwash Development type commercial Soil Group A Size (ac.) 2.68 Existing surface soil, paving Detention/Retention Retention Predev Cover forest 2) Existing onsite characteristics: forest 2.68 acres Assume forested per DOE Manual 3) Developed onsite characteristics: landscape 0.24 acres Impervious acres: 2.44 acres roof 0.85 acres walks 0.07 acres paving 1.52 acres Step 3) Developed stormwater discharge criteria 1. Flow control required. Infiltration all site runoff. the range of pre-developed discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow. 2. Basic Runoff Treatment provided to meet the 91% storm event. Step 4) Flow Control Facility Proposed 39 qty ~ Stormtech MC-3500 chambers in 107' X 23' rock gallery 100% onsite retention provided Page 12 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Page 13 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ STORMWATER DATA - BASIN 'B' Project Name: GAYTEWAY - BULDING 'B' By: P.A.D. Project Number: 18005 Date: 3/4/19 DRAINAGE CRITERIA: CITY OF ARLINGTON RAINFALL METHOD: WWHM Step 1) Site Data 1) General characteristics: Basin B Soil type outwash Development type commercial Soil Group A Size (ac.) 0.62 Existing surface soil, paving Detention/Retention Retention Predev Cover forest 2) Existing onsite characteristics: Pervious acres 0.62 acres forest 0.62 acres Assume forested per DOE Manual Impervious acres 0.00 acres pavement 0.00 acres 3) Developed onsite characteristics: Pervious acres 0.00 acres landscape 0.00 acres Impervious acres: 0.62 acres roof 0.62 acres paving 0.00 acres Step 3) Developed stormwater discharge criteria 1. Flow control required. Infiltration all runoff Step 4) Flow Control Facility Proposed 12 qty ~ Stormtech MC-3500 chambers in 53' X 16' rock gallery 100% onsite retention. Page 14 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ Page 15 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ WATER QUALITY TREATMENT CALCULATIONS Project Name: GAYTEWAY - BULDING 'B' By: P.A.D. Project Number: 18005 Date: 3/5/19 DRAINAGE CRITERIA: CITY OF ARLINGTON RAINFALL METHOD: WWHM CB #4 - BAYFILTER MH Step 1) Calculate design flows Alandscape= 0.24 ac Awalks= 0.07 ac Apaving= 1.52 ac WWHM results Water Quality BMP Flow and Volume for POC 3 . On-line facility volume: 0.1984 acre-feet On-line facility target flow (15min): 0.3031 cfs. Off-line facility target flow (15min): 0.1717 cfs. If no high flow bypass: Q25 1.760 cfs Water quality flow: Qwq 0.172 cfs "Off-Line" treatment, 15min Flow Rate Use internal bypass structure inside MH Step 2) Calculate Number of Cartridges Use Bayfilter treatment cartridges, Model: 545 Invert Drop (in) = 2.83 Treatment Rate (gpm / cart)= 45 N = Number of Cartridges = Qwq * 449 gpm / cfs / (treatment rate) = 1.72 ===> USE 2 CARTRIDGES -BAYFILTER 545 CARTRIDGE USE 72" DIA. BAYFILTER MH W/ INTERNAL BYPASS Page 16 Q/Qf Vf Q/Qf < 1.0, <ok> Qf s n R DIA ) and I = P * i R Q P.A.D.3/5/19 * Tc^(-b By: Date: R I = a iR Tc CAtot 0.63 = R CA C CONVEYANCE SYSTEM DESIGN = 2.66 b R A GAYTEWAY - BLDG C18005CITY OF ARLINGTONRATIONAL METHOD25YR / 24HR TO P(in) = 3.0 11 191817161015a1418131712160.071015140.249130.1180.85120.117100.2160.9040.000.900.060.17250.9080.15240.9070.220.100.9060.100.100.06230.9040.10220.900.180.190.220.90240.110.000.32320.82210.106.30.150.41310.100.140.830.60226.30.090.850.6030202.56.30.080.270.850.76296.30.100.870.8928312.50.156.30.98272.50.0926.30.170.151.120.902.50.096.30.0318005-Storm-CLC-B.xls,CONVEY0.90292.50.096.30.540.15282.56.30.120.790.240.90272.56.30.240.001.0480.330.902.530.091.510.416.32.50.191.5180.906.32.50.0120.150.131.8980.240.906.30.030.202.2380.332.56.30.012120.002.462.50.900.012120.112.810.152.50.900.00790.0126.3120.000.182.50.900.0126.30.37120.840.00660.0120.61120.170.110.00662.50.0126.30.82120.120.110.00662.50.0126.31.040.181.180.00360.01280.000.170.00362.50.0126.380.611.080.290.00362.56.380.831.080.470.00360.01281.080.473.30.00500.0122.56.30.382.340.00800.0122.56.30.4582.343.10.0126.382.340.00663.12.56.30.272.340.00660.133.12.50.0120.2762.760.00803.02.50.01263.490.14573.00.502.50.433.00.730.0121.080.7263.00.960.01000.0121.081.1760.643.50.01001.191.170.644.40.0125.0660.810.01000.01283.10.950.081783.11.330.890.01283.41.330.800.01000.01214.40.01000.0120.350.620.0120.561.763.80.01000.693.80.01000.210.620.01030.623.10.29100.468.90.620.631.333.11.340.623.17.150.263.10.443.83.80.4420.30.700.540.870.16 FROM Project Name:Project Number:DRAINAGE CRITERIA:RAINFALL METHOD:DESIGN STORM: Page 17 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ SECTION 6 - CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN An Erosion Control Plan and Construction Stormwater Pollution Prevention Plan is provided with our Civil Permit submittal. SECTION 7 - SPECIAL REPORTS & STUDIES The existing soils are classified as Everett Very Gravelly Sany Loam, 0- to 8 percent slopes according to the National Cooperative Soil Survey by the USDA Natural Resources Conservation Service. Infilration study and geotechnical report provided within Appendix B. SECTION 8 - OTHER PERMITS A Department of Ecology Construction Stormwater Permit has been obtained (WAR307838). SECTION 9 - OPERATION MAINTENANCE MANUAL, SOURCE CONTROL A Stormwater Operation Maintenance Manual and site Source Control measures will be provided with the final permit submittal. SECTION 10 - BOND QUANTITIES WORKSHEET A Bond Quantities Worksheet will be submitted with our Civil Permit. Page 18 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX A â€“ WWHM CALCULATIONS A-1 WWHM2012 PROJECT REPORT A-2 General Model Information Project Name: 18005-B-wwhm Site Name: GAYTE BUSINESS PARK Site Address: 20015 67TH AVE NE City: ARLINGTON Report Date: 3/9/2019 Gage: Everett Data Start: 1948/10/01 Data End: 2009/09/30 Timestep: 15 Minute Precip Scale: 1.200 Version Date: 2016/11/23 Version: 4.2.13 POC Thresholds Low Flow Threshold for POC1: 50 Percent of the 2 Year High Flow Threshold for POC1: 50 Year Low Flow Threshold for POC2: 50 Percent of the 2 Year High Flow Threshold for POC2: 50 Year Low Flow Threshold for POC3: 50 Percent of the 2 Year High Flow Threshold for POC3: 50 Year 18005-B-wwhm 3/9/2019 6:31:18 AM Page 2 A-3 Landuse Basin Data Predeveloped Land Use B-1 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 2.68 Pervious Total 2.68 Impervious Land Use acre Impervious Total 0 Basin Total 2.68 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 3 A-4 Basin 2 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 4.42 Pervious Total 4.42 Impervious Land Use acre Impervious Total 0 Basin Total 4.42 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 4 A-5 B-WQ Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 1.83 Pervious Total 1.83 Impervious Land Use acre Impervious Total 0 Basin Total 1.83 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 5 A-6 B-2 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 0.62 Pervious Total 0.62 Impervious Land Use acre Impervious Total 0 Basin Total 0.62 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 6 A-7 Mitigated Land Use Basin A Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.24 Pervious Total 0.24 Impervious Land Use acre ROOF TOPS FLAT 0.85 SIDEWALKS FLAT 0.07 PARKING FLAT 1.52 Impervious Total 2.44 Basin Total 2.68 Element Flows To: Surface Interflow Groundwater StormTech A StormTech A 18005-B-wwhm 3/9/2019 6:31:18 AM Page 7 A-8 WQ Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.24 Pervious Total 0.24 Impervious Land Use acre SIDEWALKS FLAT 0.07 PARKING FLAT 1.52 Impervious Total 1.59 Basin Total 1.83 Element Flows To: Surface Interflow Groundwater 18005-B-wwhm 3/9/2019 6:31:18 AM Page 8 A-9 Basin B Bypass: No GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 0.62 Impervious Total 0.62 Basin Total 0.62 Element Flows To: Surface Interflow Groundwater StormTech-B StormTech-B 18005-B-wwhm 3/9/2019 6:31:18 AM Page 9 A-10 Routing Elements Predeveloped Routing 18005-B-wwhm 3/9/2019 6:31:18 AM Page 10 A-11 Mitigated Routing StormTech A Chamber Model: 3500 Dimensions Max Row Length: 110 Number of Chambers: 39 Number of Endcaps: 6 Top Stone Depth: 12 Bottom Stone Depth: 9 Infiltration On Infiltration rate: 38 Infiltration safety factor: 0.36 Total Volume Infiltrated (ac-ft.): 498.335 Total Volume Through Riser (ac-ft.): 0 Total Volume Through Facility (ac-ft.): 498.335 Percent Infiltrated: 100 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 5.5 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 StormTech Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 3.0000 0.098 0.000 0.000 0.000 3.0667 0.098 0.006 0.000 1.358 3.1333 0.098 0.013 0.000 1.358 3.2000 0.098 0.019 0.000 1.358 3.2667 0.098 0.026 0.000 1.358 3.3333 0.098 0.032 0.000 1.358 3.4000 0.098 0.039 0.000 1.358 3.4667 0.098 0.046 0.000 1.358 3.5333 0.098 0.052 0.000 1.358 3.6000 0.098 0.059 0.000 1.358 3.6667 0.098 0.065 0.000 1.358 3.7333 0.098 0.072 0.000 1.358 3.8000 0.098 0.078 0.000 1.358 3.8667 0.098 0.085 0.000 1.358 3.9333 0.098 0.091 0.000 1.358 4.0000 0.098 0.098 0.000 1.358 4.0667 0.098 0.105 0.000 1.358 4.1333 0.098 0.111 0.000 1.358 4.2000 0.098 0.118 0.000 1.358 4.2667 0.098 0.124 0.000 1.358 4.3333 0.098 0.131 0.000 1.358 4.4000 0.098 0.137 0.000 1.358 4.4667 0.098 0.144 0.000 1.358 4.5333 0.098 0.151 0.000 1.358 4.6000 0.098 0.157 0.000 1.358 4.6667 0.098 0.164 0.000 1.358 4.7333 0.098 0.170 0.000 1.358 4.8000 0.098 0.177 0.000 1.358 18005-B-wwhm 3/9/2019 6:31:18 AM Page 11 A-12 4.8667 0.098 0.183 0.000 1.358 4.9333 0.098 0.190 0.000 1.358 5.0000 0.098 0.197 0.000 1.358 5.0667 0.098 0.203 0.000 1.358 5.1333 0.098 0.210 0.000 1.358 5.2000 0.098 0.216 0.000 1.358 5.2667 0.098 0.223 0.000 1.358 5.3333 0.098 0.229 0.000 1.358 5.4000 0.098 0.236 0.000 1.358 5.4667 0.098 0.242 0.000 1.358 5.5333 0.098 0.249 0.000 1.358 5.6000 0.098 0.256 0.000 1.358 5.6667 0.098 0.262 0.000 1.358 5.7333 0.098 0.269 0.000 1.358 5.8000 0.098 0.275 0.000 1.358 5.8667 0.098 0.282 0.000 1.358 5.9333 0.098 0.288 0.000 1.358 6.0000 0.098 0.295 0.000 1.358 6.0667 0.098 0.302 0.000 1.358 6.1333 0.098 0.308 0.000 1.358 6.2000 0.098 0.315 0.000 1.358 6.2667 0.098 0.321 0.000 1.358 6.3333 0.098 0.328 0.000 1.358 6.4000 0.098 0.334 0.000 1.358 6.4667 0.098 0.341 0.000 1.358 6.5333 0.098 0.348 0.000 1.358 6.6000 0.098 0.354 0.000 1.358 6.6667 0.098 0.361 0.000 1.358 6.7333 0.098 0.367 0.000 1.358 6.8000 0.098 0.374 0.000 1.358 6.8667 0.098 0.380 0.000 1.358 6.9333 0.098 0.387 0.000 1.358 7.0000 0.098 0.393 0.000 1.358 7.0667 0.098 0.400 0.000 1.358 7.1333 0.098 0.407 0.000 1.358 7.2000 0.098 0.413 0.000 1.358 7.2667 0.098 0.420 0.000 1.358 7.3333 0.098 0.426 0.000 1.358 7.4000 0.098 0.433 0.000 1.358 7.4667 0.098 0.439 0.000 1.358 7.5333 0.098 0.446 0.000 1.358 7.6000 0.098 0.453 0.000 1.358 7.6667 0.098 0.459 0.000 1.358 7.7333 0.098 0.466 0.000 1.358 7.8000 0.098 0.472 0.000 1.358 7.8667 0.098 0.479 0.000 1.358 7.9333 0.098 0.485 0.000 1.358 8.0000 0.098 0.492 0.000 1.358 8.0667 0.098 0.499 0.000 1.358 8.1333 0.098 0.505 0.000 1.358 8.2000 0.098 0.512 0.000 1.358 8.2667 0.098 0.518 0.000 1.358 8.3333 0.098 0.525 0.000 1.358 8.4000 0.098 0.531 0.000 1.358 8.4667 0.098 0.538 0.000 1.358 8.5333 0.098 0.544 0.064 1.358 8.6000 0.098 0.551 0.333 1.358 8.6667 0.098 0.558 0.703 1.358 18005-B-wwhm 3/9/2019 6:31:18 AM Page 12 A-13 8.7333 0.098 0.564 1.115 1.358 8.8000 0.098 0.571 1.509 1.358 8.8667 0.098 0.577 1.834 1.358 8.9333 0.098 0.584 2.060 1.358 9.0000 0.098 0.590 2.203 1.358 9.0667 0.098 0.597 2.371 1.358 9.1333 0.000 0.000 2.506 0.000 18005-B-wwhm 3/9/2019 6:31:18 AM Page 13 A-14 StormTech-B Chamber Model: 3500 Dimensions Max Row Length: 53 Number of Chambers: 12 Number of Endcaps: 4 Top Stone Depth: 12 Bottom Stone Depth: 9 Infiltration On Infiltration rate: 38 Infiltration safety factor: 0.36 Total Volume Infiltrated (ac-ft.): 119.795 Total Volume Through Riser (ac-ft.): 0 Total Volume Through Facility (ac-ft.): 119.795 Percent Infiltrated: 100 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 5.5 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 StormTech Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 3.0000 0.014 0.000 0.000 0.000 3.0444 0.014 0.000 0.000 0.201 3.0889 0.014 0.001 0.000 0.201 3.1333 0.014 0.001 0.000 0.201 3.1778 0.014 0.002 0.000 0.201 3.2222 0.014 0.003 0.000 0.201 3.2667 0.014 0.003 0.000 0.201 3.3111 0.014 0.004 0.000 0.201 3.3556 0.014 0.005 0.000 0.201 3.4000 0.014 0.005 0.000 0.201 3.4444 0.014 0.006 0.000 0.201 3.4889 0.014 0.007 0.000 0.201 3.5333 0.014 0.007 0.000 0.201 3.5778 0.014 0.008 0.000 0.201 3.6222 0.014 0.009 0.000 0.201 3.6667 0.014 0.009 0.000 0.201 3.7111 0.014 0.010 0.000 0.201 3.7556 0.014 0.011 0.000 0.201 3.8000 0.014 0.011 0.000 0.201 3.8444 0.014 0.012 0.000 0.201 3.8889 0.014 0.013 0.000 0.201 3.9333 0.014 0.013 0.000 0.201 3.9778 0.014 0.014 0.000 0.201 4.0222 0.014 0.014 0.000 0.201 4.0667 0.014 0.015 0.000 0.201 4.1111 0.014 0.016 0.000 0.201 4.1556 0.014 0.016 0.000 0.201 4.2000 0.014 0.017 0.000 0.201 4.2444 0.014 0.018 0.000 0.201 4.2889 0.014 0.018 0.000 0.201 18005-B-wwhm 3/9/2019 6:31:18 AM Page 14 A-15 4.3333 0.014 0.019 0.000 0.201 4.3778 0.014 0.020 0.000 0.201 4.4222 0.014 0.020 0.000 0.201 4.4667 0.014 0.021 0.000 0.201 4.5111 0.014 0.022 0.000 0.201 4.5556 0.014 0.022 0.000 0.201 4.6000 0.014 0.023 0.000 0.201 4.6444 0.014 0.024 0.000 0.201 4.6889 0.014 0.024 0.000 0.201 4.7333 0.014 0.025 0.000 0.201 4.7778 0.014 0.026 0.000 0.201 4.8222 0.014 0.026 0.000 0.201 4.8667 0.014 0.027 0.000 0.201 4.9111 0.014 0.027 0.000 0.201 4.9556 0.014 0.028 0.000 0.201 5.0000 0.014 0.029 0.000 0.201 5.0444 0.014 0.029 0.000 0.201 5.0889 0.014 0.030 0.000 0.201 5.1333 0.014 0.031 0.000 0.201 5.1778 0.014 0.031 0.000 0.201 5.2222 0.014 0.032 0.000 0.201 5.2667 0.014 0.033 0.000 0.201 5.3111 0.014 0.033 0.000 0.201 5.3556 0.014 0.034 0.000 0.201 5.4000 0.014 0.035 0.000 0.201 5.4444 0.014 0.035 0.000 0.201 5.4889 0.014 0.036 0.000 0.201 5.5333 0.014 0.037 0.000 0.201 5.5778 0.014 0.037 0.000 0.201 5.6222 0.014 0.038 0.000 0.201 5.6667 0.014 0.038 0.000 0.201 5.7111 0.014 0.039 0.000 0.201 5.7556 0.014 0.040 0.000 0.201 5.8000 0.014 0.040 0.000 0.201 5.8444 0.014 0.041 0.000 0.201 5.8889 0.014 0.042 0.000 0.201 5.9333 0.014 0.042 0.000 0.201 5.9778 0.014 0.043 0.000 0.201 6.0222 0.014 0.044 0.000 0.201 6.0667 0.014 0.044 0.000 0.201 6.1111 0.014 0.045 0.000 0.201 6.1556 0.014 0.046 0.000 0.201 6.2000 0.014 0.046 0.000 0.201 6.2444 0.014 0.047 0.000 0.201 6.2889 0.014 0.048 0.000 0.201 6.3333 0.014 0.048 0.000 0.201 6.3778 0.014 0.049 0.000 0.201 6.4222 0.014 0.050 0.000 0.201 6.4667 0.014 0.050 0.000 0.201 6.5111 0.014 0.051 0.000 0.201 6.5556 0.014 0.051 0.000 0.201 6.6000 0.014 0.052 0.000 0.201 6.6444 0.014 0.053 0.000 0.201 6.6889 0.014 0.053 0.000 0.201 6.7333 0.014 0.054 0.000 0.201 6.7778 0.014 0.055 0.000 0.201 6.8222 0.014 0.055 0.000 0.201 6.8667 0.014 0.056 0.000 0.201 18005-B-wwhm 3/9/2019 6:31:18 AM Page 15 A-16 6.9111 0.014 0.057 0.000 0.201 6.9556 0.014 0.057 0.000 0.201 7.0000 0.014 0.058 0.000 0.201 7.0444 0.014 0.059 0.000 0.201 7.0889 0.000 0.000 0.000 0.000 18005-B-wwhm 3/9/2019 6:31:19 AM Page 16 A-17 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 7.1 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.24 Total Impervious Area: 2.44 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.008149 5 year 0.017675 10 year 0.028352 25 year 0.049518 50 year 0.073172 100 year 0.106139 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.006 0.000 1950 0.017 0.000 1951 0.012 0.000 1952 0.006 0.000 1953 0.006 0.000 1954 0.039 0.000 1955 0.030 0.000 1956 0.006 0.000 1957 0.006 0.000 1958 0.006 0.000 18005-B-wwhm 3/9/2019 6:31:19 AM Page 17 A-18 1959 0.013 0.000 1960 0.010 0.000 1961 0.027 0.000 1962 0.006 0.000 1963 0.006 0.000 1964 0.019 0.000 1965 0.006 0.000 1966 0.006 0.000 1967 0.011 0.000 1968 0.006 0.000 1969 0.006 0.000 1970 0.006 0.000 1971 0.028 0.000 1972 0.006 0.000 1973 0.006 0.000 1974 0.015 0.000 1975 0.005 0.000 1976 0.013 0.000 1977 0.006 0.000 1978 0.006 0.000 1979 0.011 0.000 1980 0.006 0.000 1981 0.006 0.000 1982 0.008 0.000 1983 0.006 0.000 1984 0.006 0.000 1985 0.010 0.000 1986 0.050 0.000 1987 0.033 0.000 1988 0.006 0.000 1989 0.005 0.000 1990 0.006 0.000 1991 0.006 0.000 1992 0.006 0.000 1993 0.006 0.000 1994 0.005 0.000 1995 0.007 0.000 1996 0.064 0.000 1997 0.176 0.000 1998 0.006 0.000 1999 0.006 0.000 2000 0.011 0.000 2001 0.005 0.000 2002 0.006 0.000 2003 0.004 0.000 2004 0.006 0.000 2005 0.006 0.000 2006 0.189 0.000 2007 0.006 0.000 2008 0.009 0.000 2009 0.006 0.000 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1891 0.0000 2 0.1758 0.0000 3 0.0642 0.0000 18005-B-wwhm 3/9/2019 6:32:35 AM Page 18 A-19 4 0.0500 0.0000 5 0.0391 0.0000 6 0.0328 0.0000 7 0.0296 0.0000 8 0.0276 0.0000 9 0.0267 0.0000 10 0.0186 0.0000 11 0.0166 0.0000 12 0.0149 0.0000 13 0.0129 0.0000 14 0.0128 0.0000 15 0.0118 0.0000 16 0.0113 0.0000 17 0.0111 0.0000 18 0.0106 0.0000 19 0.0104 0.0000 20 0.0095 0.0000 21 0.0086 0.0000 22 0.0084 0.0000 23 0.0067 0.0000 24 0.0057 0.0000 25 0.0057 0.0000 26 0.0057 0.0000 27 0.0057 0.0000 28 0.0057 0.0000 29 0.0057 0.0000 30 0.0057 0.0000 31 0.0057 0.0000 32 0.0057 0.0000 33 0.0057 0.0000 34 0.0057 0.0000 35 0.0057 0.0000 36 0.0057 0.0000 37 0.0057 0.0000 38 0.0057 0.0000 39 0.0057 0.0000 40 0.0057 0.0000 41 0.0057 0.0000 42 0.0057 0.0000 43 0.0057 0.0000 44 0.0056 0.0000 45 0.0056 0.0000 46 0.0056 0.0000 47 0.0056 0.0000 48 0.0056 0.0000 49 0.0056 0.0000 50 0.0056 0.0000 51 0.0056 0.0000 52 0.0056 0.0000 53 0.0056 0.0000 54 0.0056 0.0000 55 0.0055 0.0000 56 0.0055 0.0000 57 0.0055 0.0000 58 0.0055 0.0000 59 0.0053 0.0000 60 0.0049 0.0000 61 0.0039 0.0000 18005-B-wwhm 3/9/2019 6:32:35 AM Page 19 A-20 18005-B-wwhm 3/9/2019 6:32:35 AM Page 20 A-21 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0041 2357 0 0 Pass 0.0048 1323 0 0 Pass 0.0055 433 0 0 Pass 0.0062 112 0 0 Pass 0.0069 102 0 0 Pass 0.0076 89 0 0 Pass 0.0083 77 0 0 Pass 0.0090 66 0 0 Pass 0.0097 61 0 0 Pass 0.0104 58 0 0 Pass 0.0111 54 0 0 Pass 0.0118 50 0 0 Pass 0.0124 49 0 0 Pass 0.0131 47 0 0 Pass 0.0138 43 0 0 Pass 0.0145 40 0 0 Pass 0.0152 36 0 0 Pass 0.0159 36 0 0 Pass 0.0166 32 0 0 Pass 0.0173 31 0 0 Pass 0.0180 31 0 0 Pass 0.0187 29 0 0 Pass 0.0194 29 0 0 Pass 0.0201 27 0 0 Pass 0.0208 26 0 0 Pass 0.0215 26 0 0 Pass 0.0222 26 0 0 Pass 0.0229 25 0 0 Pass 0.0236 23 0 0 Pass 0.0243 23 0 0 Pass 0.0250 23 0 0 Pass 0.0257 23 0 0 Pass 0.0264 23 0 0 Pass 0.0271 21 0 0 Pass 0.0278 19 0 0 Pass 0.0285 18 0 0 Pass 0.0292 17 0 0 Pass 0.0299 16 0 0 Pass 0.0306 16 0 0 Pass 0.0313 15 0 0 Pass 0.0320 15 0 0 Pass 0.0327 14 0 0 Pass 0.0334 13 0 0 Pass 0.0341 13 0 0 Pass 0.0348 13 0 0 Pass 0.0355 13 0 0 Pass 0.0362 13 0 0 Pass 0.0369 13 0 0 Pass 0.0376 13 0 0 Pass 0.0383 13 0 0 Pass 0.0390 13 0 0 Pass 0.0397 11 0 0 Pass 0.0404 11 0 0 Pass 18005-B-wwhm 3/9/2019 6:32:35 AM Page 21 A-22 0.0411 11 0 0 Pass 0.0418 11 0 0 Pass 0.0425 11 0 0 Pass 0.0432 11 0 0 Pass 0.0439 11 0 0 Pass 0.0446 11 0 0 Pass 0.0453 11 0 0 Pass 0.0460 11 0 0 Pass 0.0466 11 0 0 Pass 0.0473 11 0 0 Pass 0.0480 11 0 0 Pass 0.0487 10 0 0 Pass 0.0494 10 0 0 Pass 0.0501 9 0 0 Pass 0.0508 9 0 0 Pass 0.0515 8 0 0 Pass 0.0522 8 0 0 Pass 0.0529 8 0 0 Pass 0.0536 8 0 0 Pass 0.0543 8 0 0 Pass 0.0550 8 0 0 Pass 0.0557 8 0 0 Pass 0.0564 8 0 0 Pass 0.0571 8 0 0 Pass 0.0578 8 0 0 Pass 0.0585 8 0 0 Pass 0.0592 8 0 0 Pass 0.0599 8 0 0 Pass 0.0606 8 0 0 Pass 0.0613 8 0 0 Pass 0.0620 7 0 0 Pass 0.0627 7 0 0 Pass 0.0634 7 0 0 Pass 0.0641 7 0 0 Pass 0.0648 6 0 0 Pass 0.0655 6 0 0 Pass 0.0662 6 0 0 Pass 0.0669 6 0 0 Pass 0.0676 6 0 0 Pass 0.0683 6 0 0 Pass 0.0690 6 0 0 Pass 0.0697 6 0 0 Pass 0.0704 6 0 0 Pass 0.0711 6 0 0 Pass 0.0718 6 0 0 Pass 0.0725 5 0 0 Pass 0.0732 5 0 0 Pass 18005-B-wwhm 3/9/2019 6:32:35 AM Page 22 A-23 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0.4876 acre-feet On-line facility target flow: 0.7522 cfs. Adjusted for 15 min: 0.7522 cfs. Off-line facility target flow: 0.4268 cfs. Adjusted for 15 min: 0.4268 cfs. 18005-B-wwhm 3/9/2019 6:32:35 AM Page 23 A-24 LID Report 18005-B-wwhm 3/9/2019 6:32:35 AM Page 24 A-25 POC 2 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #2 Total Pervious Area: 0.62 Total Impervious Area: 0 Mitigated Landuse Totals for POC #2 Total Pervious Area: 0 Total Impervious Area: 0.62 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #2 Return Period Flow(cfs) 2 year 0.000712 5 year 0.001543 10 year 0.002476 25 year 0.004324 50 year 0.00639 100 year 0.009268 Flow Frequency Return Periods for Mitigated. POC #2 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #2 Year Predeveloped Mitigated 1949 0.000 0.000 1950 0.001 0.000 1951 0.001 0.000 1952 0.000 0.000 1953 0.000 0.000 1954 0.003 0.000 1955 0.003 0.000 1956 0.000 0.000 1957 0.000 0.000 1958 0.000 0.000 1959 0.001 0.000 18005-B-wwhm 3/9/2019 6:33:37 AM Page 25 A-26 1960 0.001 0.000 1961 0.002 0.000 1962 0.000 0.000 1963 0.000 0.000 1964 0.002 0.000 1965 0.000 0.000 1966 0.000 0.000 1967 0.001 0.000 1968 0.000 0.000 1969 0.000 0.000 1970 0.000 0.000 1971 0.002 0.000 1972 0.000 0.000 1973 0.000 0.000 1974 0.001 0.000 1975 0.000 0.000 1976 0.001 0.000 1977 0.000 0.000 1978 0.000 0.000 1979 0.001 0.000 1980 0.000 0.000 1981 0.000 0.000 1982 0.001 0.000 1983 0.000 0.000 1984 0.000 0.000 1985 0.001 0.000 1986 0.004 0.000 1987 0.003 0.000 1988 0.000 0.000 1989 0.000 0.000 1990 0.000 0.000 1991 0.000 0.000 1992 0.000 0.000 1993 0.000 0.000 1994 0.000 0.000 1995 0.001 0.000 1996 0.006 0.000 1997 0.015 0.000 1998 0.000 0.000 1999 0.000 0.000 2000 0.001 0.000 2001 0.000 0.000 2002 0.000 0.000 2003 0.000 0.000 2004 0.000 0.000 2005 0.000 0.000 2006 0.017 0.000 2007 0.000 0.000 2008 0.001 0.000 2009 0.000 0.000 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #2 Rank Predeveloped Mitigated 1 0.0165 0.0000 2 0.0153 0.0000 3 0.0056 0.0000 4 0.0044 0.0000 18005-B-wwhm 3/9/2019 6:34:12 AM Page 26 A-27 5 0.0034 0.0000 6 0.0029 0.0000 7 0.0026 0.0000 8 0.0024 0.0000 9 0.0023 0.0000 10 0.0016 0.0000 11 0.0015 0.0000 12 0.0013 0.0000 13 0.0011 0.0000 14 0.0011 0.0000 15 0.0010 0.0000 16 0.0010 0.0000 17 0.0010 0.0000 18 0.0009 0.0000 19 0.0009 0.0000 20 0.0008 0.0000 21 0.0008 0.0000 22 0.0007 0.0000 23 0.0006 0.0000 24 0.0005 0.0000 25 0.0005 0.0000 26 0.0005 0.0000 27 0.0005 0.0000 28 0.0005 0.0000 29 0.0005 0.0000 30 0.0005 0.0000 31 0.0005 0.0000 32 0.0005 0.0000 33 0.0005 0.0000 34 0.0005 0.0000 35 0.0005 0.0000 36 0.0005 0.0000 37 0.0005 0.0000 38 0.0005 0.0000 39 0.0005 0.0000 40 0.0005 0.0000 41 0.0005 0.0000 42 0.0005 0.0000 43 0.0005 0.0000 44 0.0005 0.0000 45 0.0005 0.0000 46 0.0005 0.0000 47 0.0005 0.0000 48 0.0005 0.0000 49 0.0005 0.0000 50 0.0005 0.0000 51 0.0005 0.0000 52 0.0005 0.0000 53 0.0005 0.0000 54 0.0005 0.0000 55 0.0005 0.0000 56 0.0005 0.0000 57 0.0005 0.0000 58 0.0005 0.0000 59 0.0005 0.0000 60 0.0004 0.0000 61 0.0003 0.0000 18005-B-wwhm 3/9/2019 6:34:12 AM Page 27 A-28 18005-B-wwhm 3/9/2019 6:34:12 AM Page 28 A-29 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0004 2353 0 0 Pass 0.0004 1338 0 0 Pass 0.0005 445 0 0 Pass 0.0005 112 0 0 Pass 0.0006 103 0 0 Pass 0.0007 89 0 0 Pass 0.0007 77 0 0 Pass 0.0008 66 0 0 Pass 0.0008 61 0 0 Pass 0.0009 58 0 0 Pass 0.0010 54 0 0 Pass 0.0010 50 0 0 Pass 0.0011 49 0 0 Pass 0.0011 47 0 0 Pass 0.0012 43 0 0 Pass 0.0013 40 0 0 Pass 0.0013 36 0 0 Pass 0.0014 36 0 0 Pass 0.0015 32 0 0 Pass 0.0015 31 0 0 Pass 0.0016 31 0 0 Pass 0.0016 29 0 0 Pass 0.0017 29 0 0 Pass 0.0018 27 0 0 Pass 0.0018 26 0 0 Pass 0.0019 26 0 0 Pass 0.0019 26 0 0 Pass 0.0020 25 0 0 Pass 0.0021 23 0 0 Pass 0.0021 23 0 0 Pass 0.0022 23 0 0 Pass 0.0022 23 0 0 Pass 0.0023 23 0 0 Pass 0.0024 21 0 0 Pass 0.0024 19 0 0 Pass 0.0025 18 0 0 Pass 0.0026 17 0 0 Pass 0.0026 16 0 0 Pass 0.0027 16 0 0 Pass 0.0027 15 0 0 Pass 0.0028 15 0 0 Pass 0.0029 14 0 0 Pass 0.0029 13 0 0 Pass 0.0030 13 0 0 Pass 0.0030 13 0 0 Pass 0.0031 13 0 0 Pass 0.0032 13 0 0 Pass 0.0032 13 0 0 Pass 0.0033 13 0 0 Pass 0.0033 13 0 0 Pass 0.0034 13 0 0 Pass 0.0035 11 0 0 Pass 0.0035 11 0 0 Pass 18005-B-wwhm 3/9/2019 6:34:12 AM Page 29 A-30 0.0036 11 0 0 Pass 0.0036 11 0 0 Pass 0.0037 11 0 0 Pass 0.0038 11 0 0 Pass 0.0038 11 0 0 Pass 0.0039 11 0 0 Pass 0.0040 11 0 0 Pass 0.0040 11 0 0 Pass 0.0041 11 0 0 Pass 0.0041 11 0 0 Pass 0.0042 11 0 0 Pass 0.0043 10 0 0 Pass 0.0043 10 0 0 Pass 0.0044 9 0 0 Pass 0.0044 9 0 0 Pass 0.0045 8 0 0 Pass 0.0046 8 0 0 Pass 0.0046 8 0 0 Pass 0.0047 8 0 0 Pass 0.0047 8 0 0 Pass 0.0048 8 0 0 Pass 0.0049 8 0 0 Pass 0.0049 8 0 0 Pass 0.0050 8 0 0 Pass 0.0050 8 0 0 Pass 0.0051 8 0 0 Pass 0.0052 8 0 0 Pass 0.0052 8 0 0 Pass 0.0053 8 0 0 Pass 0.0054 8 0 0 Pass 0.0054 7 0 0 Pass 0.0055 7 0 0 Pass 0.0055 7 0 0 Pass 0.0056 7 0 0 Pass 0.0057 6 0 0 Pass 0.0057 6 0 0 Pass 0.0058 6 0 0 Pass 0.0058 6 0 0 Pass 0.0059 6 0 0 Pass 0.0060 6 0 0 Pass 0.0060 6 0 0 Pass 0.0061 6 0 0 Pass 0.0061 6 0 0 Pass 0.0062 6 0 0 Pass 0.0063 6 0 0 Pass 0.0063 5 0 0 Pass 0.0064 5 0 0 Pass 18005-B-wwhm 3/9/2019 6:34:12 AM Page 30 A-31 Water Quality Water Quality BMP Flow and Volume for POC #2 On-line facility volume: 0.3061 acre-feet On-line facility target flow: 0.4605 cfs. Adjusted for 15 min: 0.4605 cfs. Off-line facility target flow: 0.2604 cfs. Adjusted for 15 min: 0.2604 cfs. 18005-B-wwhm 3/9/2019 6:34:12 AM Page 31 A-32 LID Report 18005-B-wwhm 3/9/2019 6:34:12 AM Page 32 A-33 POC 3 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #3 Total Pervious Area: 1.83 Total Impervious Area: 0 Mitigated Landuse Totals for POC #3 Total Pervious Area: 0.24 Total Impervious Area: 1.59 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #3 Return Period Flow(cfs) 2 year 0.0021 5 year 0.004556 10 year 0.007308 25 year 0.012763 50 year 0.01886 100 year 0.027357 Flow Frequency Return Periods for Mitigated. POC #3 Return Period Flow(cfs) 2 year 0.876721 5 year 1.196789 10 year 1.432454 25 year 1.758376 50 year 2.022372 100 year 2.305191 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #3 Year Predeveloped Mitigated 1949 0.001 0.964 1950 0.004 1.040 1951 0.003 1.050 1952 0.001 0.826 1953 0.001 1.072 1954 0.010 1.374 1955 0.008 1.043 1956 0.001 0.458 1957 0.001 0.794 1958 0.001 2.060 1959 0.003 0.792 18005-B-wwhm 3/9/2019 6:34:12 AM Page 33 A-34 1960 0.003 0.818 1961 0.007 2.660 1962 0.001 0.972 1963 0.001 1.132 1964 0.005 0.604 1965 0.001 0.739 1966 0.001 0.753 1967 0.003 1.658 1968 0.001 0.904 1969 0.001 1.846 1970 0.001 0.687 1971 0.007 0.971 1972 0.001 1.257 1973 0.001 1.017 1974 0.004 1.250 1975 0.001 0.984 1976 0.003 0.674 1977 0.001 0.676 1978 0.001 0.496 1979 0.003 1.147 1980 0.001 0.739 1981 0.001 0.685 1982 0.002 0.689 1983 0.001 0.947 1984 0.001 0.853 1985 0.002 1.181 1986 0.013 1.161 1987 0.008 1.024 1988 0.001 0.824 1989 0.001 0.845 1990 0.001 0.658 1991 0.001 0.814 1992 0.001 0.819 1993 0.001 0.632 1994 0.001 0.715 1995 0.002 0.606 1996 0.017 0.982 1997 0.045 1.016 1998 0.001 1.138 1999 0.001 0.495 2000 0.003 1.815 2001 0.001 0.593 2002 0.001 0.576 2003 0.001 0.787 2004 0.001 1.549 2005 0.001 0.710 2006 0.049 0.895 2007 0.001 0.887 2008 0.002 0.705 2009 0.001 0.713 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #3 Rank Predeveloped Mitigated 1 0.0487 2.6596 2 0.0453 2.0597 3 0.0165 1.8463 4 0.0129 1.8147 18005-B-wwhm 3/9/2019 6:34:45 AM Page 34 A-35 5 0.0101 1.6585 6 0.0084 1.5493 7 0.0076 1.3740 8 0.0071 1.2568 9 0.0069 1.2500 10 0.0048 1.1811 11 0.0043 1.1613 12 0.0038 1.1468 13 0.0033 1.1376 14 0.0033 1.1321 15 0.0030 1.0723 16 0.0029 1.0503 17 0.0029 1.0432 18 0.0027 1.0398 19 0.0027 1.0241 20 0.0025 1.0170 21 0.0022 1.0164 22 0.0022 0.9843 23 0.0017 0.9820 24 0.0015 0.9720 25 0.0015 0.9714 26 0.0015 0.9642 27 0.0015 0.9467 28 0.0015 0.9042 29 0.0015 0.8945 30 0.0015 0.8873 31 0.0015 0.8529 32 0.0015 0.8452 33 0.0015 0.8262 34 0.0015 0.8244 35 0.0015 0.8190 36 0.0015 0.8177 37 0.0015 0.8135 38 0.0015 0.7943 39 0.0015 0.7918 40 0.0015 0.7869 41 0.0015 0.7529 42 0.0015 0.7394 43 0.0015 0.7390 44 0.0015 0.7146 45 0.0015 0.7135 46 0.0015 0.7101 47 0.0015 0.7050 48 0.0014 0.6894 49 0.0014 0.6870 50 0.0014 0.6849 51 0.0014 0.6764 52 0.0014 0.6742 53 0.0014 0.6582 54 0.0014 0.6322 55 0.0014 0.6061 56 0.0014 0.6035 57 0.0014 0.5934 58 0.0014 0.5757 59 0.0014 0.4956 60 0.0013 0.4952 61 0.0010 0.4582 18005-B-wwhm 3/9/2019 6:34:45 AM Page 35 A-36 18005-B-wwhm 3/9/2019 6:34:45 AM Page 36 A-37 Duration Flows Flow(cfs) Predev Mit Percentage Pass/Fail 0.0011 2357 629900 26724 Fail 0.0012 1330 593325 44610 Fail 0.0014 437 561028 128381 Fail 0.0016 112 534078 476855 Fail 0.0018 103 510765 495888 Fail 0.0019 89 490445 551061 Fail 0.0021 77 472265 613331 Fail 0.0023 66 456009 690922 Fail 0.0025 61 441465 723713 Fail 0.0027 58 428418 738651 Fail 0.0028 54 416440 771185 Fail 0.0030 50 405532 811064 Fail 0.0032 49 395479 807100 Fail 0.0034 47 386068 821421 Fail 0.0036 43 377512 877934 Fail 0.0037 40 369598 923995 Fail 0.0039 36 362112 1005866 Fail 0.0041 36 355268 986855 Fail 0.0043 32 348851 1090159 Fail 0.0045 31 342862 1106006 Fail 0.0046 31 337301 1088067 Fail 0.0048 29 331740 1143931 Fail 0.0050 29 326821 1126968 Fail 0.0052 27 321901 1192225 Fail 0.0054 26 317410 1220807 Fail 0.0055 26 313132 1204353 Fail 0.0057 26 308854 1187900 Fail 0.0059 25 305004 1220016 Fail 0.0061 23 301154 1309365 Fail 0.0063 23 297732 1294486 Fail 0.0064 23 294310 1279608 Fail 0.0066 23 290888 1264730 Fail 0.0068 23 287679 1250778 Fail 0.0070 21 284685 1355642 Fail 0.0072 19 281690 1482578 Fail 0.0073 18 278910 1549500 Fail 0.0075 17 276129 1624288 Fail 0.0077 16 273349 1708431 Fail 0.0079 16 270782 1692387 Fail 0.0081 15 268216 1788106 Fail 0.0082 15 265863 1772419 Fail 0.0084 14 263510 1882214 Fail 0.0086 13 261157 2008900 Fail 0.0088 13 259018 1992446 Fail 0.0090 13 256666 1974353 Fail 0.0091 13 254527 1957900 Fail 0.0093 13 252602 1943092 Fail 0.0095 13 250463 1926638 Fail 0.0097 13 248538 1911830 Fail 0.0099 13 246613 1897023 Fail 0.0100 13 244688 1882215 Fail 0.0102 11 242977 2208881 Fail 0.0104 11 241052 2191381 Fail 0.0106 11 239341 2175827 Fail 18005-B-wwhm 3/9/2019 6:34:45 AM Page 37 A-38 0.0108 11 237630 2160272 Fail 0.0109 11 235918 2144709 Fail 0.0111 11 234207 2129154 Fail 0.0113 11 232710 2115545 Fail 0.0115 11 230999 2099990 Fail 0.0117 11 229502 2086381 Fail 0.0118 11 228005 2072772 Fail 0.0120 11 226507 2059154 Fail 0.0122 11 225010 2045545 Fail 0.0124 11 223513 2031936 Fail 0.0126 10 222016 2220160 Fail 0.0127 10 220732 2207320 Fail 0.0129 9 219235 2435944 Fail 0.0131 9 217952 2421688 Fail 0.0133 8 216669 2708362 Fail 0.0135 8 215171 2689637 Fail 0.0136 8 213888 2673600 Fail 0.0138 8 212626 2657825 Fail 0.0140 8 211300 2641250 Fail 0.0142 8 209974 2624675 Fail 0.0144 8 208669 2608362 Fail 0.0145 8 207429 2592862 Fail 0.0147 8 206209 2577612 Fail 0.0149 8 205033 2562912 Fail 0.0151 8 203835 2547937 Fail 0.0153 8 202616 2532700 Fail 0.0154 8 201440 2518000 Fail 0.0156 8 200263 2503287 Fail 0.0158 8 199087 2488587 Fail 0.0160 7 197932 2827600 Fail 0.0162 7 196756 2810800 Fail 0.0163 7 195622 2794600 Fail 0.0165 7 194403 2777185 Fail 0.0167 6 193248 3220800 Fail 0.0169 6 192136 3202266 Fail 0.0171 6 191045 3184083 Fail 0.0172 6 189911 3165183 Fail 0.0174 6 188799 3146650 Fail 0.0176 6 187708 3128466 Fail 0.0178 6 186575 3109583 Fail 0.0180 6 185505 3091750 Fail 0.0181 6 184393 3073216 Fail 0.0183 6 183281 3054683 Fail 0.0185 6 182233 3037216 Fail 0.0187 5 181185 3623700 Fail 0.0189 5 180115 3602300 Fail The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. The development has an increase in flow durations for more than 50% of the flows for the range of the duration analysis. 18005-B-wwhm 3/9/2019 6:34:45 AM Page 38 A-39 Water Quality Water Quality BMP Flow and Volume for POC #3 On-line facility volume: 0.1984 acre-feet On-line facility target flow: 0.3031 cfs. Adjusted for 15 min: 0.3031 cfs. Off-line facility target flow: 0.1717 cfs. Adjusted for 15 min: 0.1717 cfs. 18005-B-wwhm 3/9/2019 6:34:45 AM Page 39 A-40 LID Report 18005-B-wwhm 3/9/2019 6:34:45 AM Page 40 A-41 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 18005-B-wwhm 3/9/2019 6:34:45 AM Page 41 A-42 Appendix Predeveloped Schematic 18005-B-wwhm 3/9/2019 6:34:45 AM Page 42 A-43 Mitigated Schematic 18005-B-wwhm 3/9/2019 6:34:46 AM Page 43 A-44 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18005-B-wwhm.wdm MESSU 25 Pre18005-B-wwhm.MES 27 Pre18005-B-wwhm.L61 28 Pre18005-B-wwhm.L62 30 POC18005-B-wwhm1.dat 32 POC18005-B-wwhm3.dat 31 POC18005-B-wwhm2.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 1 COPY 501 COPY 503 COPY 502 DISPLY 1 DISPLY 3 DISPLY 2 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 B-1 MAX 1 2 30 9 3 B-WQ MAX 1 2 32 9 2 B-2 MAX 1 2 31 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 503 1 1 502 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 A/B, Forest, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** 18005-B-wwhm 3/9/2019 6:34:46 AM Page 44 A-45 # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 1 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 1 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 1 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 1 0 5 2 400 0.05 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 1 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 1 0.2 0.5 0.35 0 0.7 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 1 0 0 0 0 3 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 45 A-46 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** B-1*** PERLND 1 2.68 COPY 501 12 PERLND 1 2.68 COPY 501 13 Basin 2*** PERLND 1 4.42 COPY 501 12 PERLND 1 4.42 COPY 501 13 B-WQ*** PERLND 1 1.83 COPY 503 12 PERLND 1 1.83 COPY 503 13 B-2*** PERLND 1 0.62 COPY 502 12 PERLND 1 0.62 COPY 502 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 COPY 503 OUTPUT MEAN 1 1 48.4 DISPLY 3 INPUT TIMSER 1 COPY 502 OUTPUT MEAN 1 1 48.4 DISPLY 2 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 46 A-47 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1.2 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1.2 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL COPY 503 OUTPUT MEAN 1 1 48.4 WDM 503 FLOW ENGL REPL COPY 502 OUTPUT MEAN 1 1 48.4 WDM 502 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN 18005-B-wwhm 3/9/2019 6:34:46 AM Page 47 A-48 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18005-B-wwhm.wdm MESSU 25 Mit18005-B-wwhm.MES 27 Mit18005-B-wwhm.L61 28 Mit18005-B-wwhm.L62 32 POC18005-B-wwhm3.dat 30 POC18005-B-wwhm1.dat 31 POC18005-B-wwhm2.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 16 IMPLND 4 IMPLND 8 IMPLND 11 RCHRES 1 RCHRES 2 COPY 503 COPY 1 COPY 501 COPY 2 COPY 502 DISPLY 3 DISPLY 1 DISPLY 2 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 3 WQ MAX 1 2 32 9 1 StormTech A MAX 1 2 30 9 2 StormTech-B MAX 1 2 31 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 503 1 1 501 1 1 2 1 1 502 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** 18005-B-wwhm 3/9/2019 6:34:46 AM Page 48 A-49 # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 16 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 16 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 16 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 16 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 4 ROOF TOPS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 11 PARKING/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 4 0 0 1 0 0 0 8 0 0 1 0 0 0 11 0 0 1 0 0 0 END ACTIVITY PRINT-INFO 18005-B-wwhm 3/9/2019 6:34:46 AM Page 49 A-50 <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 4 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 11 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 4 0 0 0 0 0 8 0 0 0 0 0 11 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 4 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 11 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 4 0 0 8 0 0 11 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 4 0 0 8 0 0 11 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin A*** PERLND 16 0.24 RCHRES 1 2 PERLND 16 0.24 RCHRES 1 3 IMPLND 4 0.85 RCHRES 1 5 IMPLND 8 0.07 RCHRES 1 5 IMPLND 11 1.52 RCHRES 1 5 Basin B*** IMPLND 4 0.62 RCHRES 2 5 WQ*** PERLND 16 0.24 COPY 503 12 PERLND 16 0.24 COPY 503 13 IMPLND 8 0.07 COPY 503 15 IMPLND 11 1.52 COPY 503 15 ******Routing****** PERLND 16 0.24 COPY 1 12 IMPLND 4 0.85 COPY 1 15 IMPLND 8 0.07 COPY 1 15 IMPLND 11 1.52 COPY 1 15 PERLND 16 0.24 COPY 1 13 IMPLND 4 0.62 COPY 2 15 RCHRES 1 1 COPY 501 17 RCHRES 2 1 COPY 502 17 END SCHEMATIC NETWORK 18005-B-wwhm 3/9/2019 6:34:46 AM Page 50 A-51 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 503 OUTPUT MEAN 1 1 48.4 DISPLY 3 INPUT TIMSER 1 COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 COPY 502 OUTPUT MEAN 1 1 48.4 DISPLY 2 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** 1 StormTech A 2 1 1 1 28 0 1 2 StormTech-B 2 1 1 1 28 0 1 END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9 2 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 2 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.02 0.0 3.0 0.5 0.0 2 2 0.01 0.0 3.0 0.5 0.0 END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 1 66 5 Depth Area Volume Outflow1 Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.048304 0.000000 0.000000 0.000000 0.083333 0.048304 0.001610 0.000000 0.666312 18005-B-wwhm 3/9/2019 6:34:46 AM Page 51 A-52 0.166667 0.048304 0.003220 0.000000 0.666312 0.250000 0.048304 0.004830 0.000000 0.666312 0.333333 0.048304 0.006441 0.000000 0.666312 0.416667 0.048304 0.008050 0.000000 0.666312 0.500000 0.048304 0.009661 0.000000 0.666312 0.583333 0.048304 0.011271 0.000000 0.666312 0.666667 0.048304 0.012880 0.000000 0.666312 0.750000 0.048304 0.014491 0.000000 0.666312 0.833333 0.048304 0.018033 0.000000 0.666312 0.916667 0.048304 0.021558 0.000000 0.666312 1.000000 0.048304 0.025071 0.000000 0.666312 1.083333 0.048304 0.028572 0.000000 0.666312 1.166667 0.048304 0.032061 0.000000 0.666312 1.250000 0.048304 0.035534 0.000000 0.666312 1.333333 0.048304 0.039002 0.000000 0.666312 1.416667 0.048304 0.042449 0.000000 0.666312 1.500000 0.048304 0.045884 0.000000 0.666312 1.583333 0.048304 0.049302 0.000000 0.666312 1.666667 0.048304 0.052705 0.000000 0.666312 1.750000 0.048304 0.056091 0.000000 0.666312 1.833333 0.048304 0.059458 0.000000 0.666312 1.916667 0.048304 0.062807 0.000000 0.666312 2.000000 0.048304 0.066136 0.000000 0.666312 2.083333 0.048304 0.069445 0.000000 0.666312 2.166667 0.048304 0.072731 0.000000 0.666312 2.250000 0.048304 0.075994 0.000000 0.666312 2.333333 0.048304 0.079233 0.000000 0.666312 2.416667 0.048304 0.082447 0.000000 0.666312 2.500000 0.048304 0.085633 0.000000 0.666312 2.583333 0.048304 0.088792 0.000000 0.666312 2.666667 0.048304 0.091920 0.000000 0.666312 2.750000 0.048304 0.095018 0.000000 0.666312 2.833333 0.048304 0.098082 0.000000 0.666312 2.916667 0.048304 0.101112 0.000000 0.666312 3.000000 0.048304 0.104106 0.000000 0.666312 3.083333 0.048304 0.107058 0.000000 0.666312 3.166667 0.048304 0.109974 0.000000 0.666312 3.250000 0.048304 0.112847 0.000000 0.666312 3.333333 0.048304 0.115674 0.000000 0.666312 3.416667 0.048304 0.118446 0.000000 0.666312 3.500000 0.048304 0.121172 0.000000 0.666312 3.583333 0.048304 0.123842 0.000000 0.666312 3.666667 0.048304 0.126451 0.000000 0.666312 3.750000 0.048304 0.128987 0.000000 0.666312 3.833333 0.048304 0.131455 0.000000 0.666312 3.916667 0.048304 0.133842 0.000000 0.666312 4.000000 0.048304 0.136133 0.000000 0.666312 4.083333 0.048304 0.138299 0.000000 0.666312 4.166667 0.048304 0.140285 0.000000 0.666312 4.250000 0.048304 0.142118 0.000000 0.666312 4.333333 0.048304 0.143888 0.000000 0.666312 4.416667 0.048304 0.145605 0.000000 0.666312 4.500000 0.048304 0.147247 0.000000 0.666312 4.583333 0.048304 0.148934 0.000000 0.666312 4.666667 0.048304 0.150544 0.000000 0.666312 4.750000 0.048304 0.152155 0.000000 0.666312 4.833333 0.048304 0.153764 0.000000 0.666312 4.916667 0.048304 0.155375 0.000000 0.666312 5.000000 0.048304 0.156985 0.000000 0.666312 5.083333 0.048304 0.158594 0.000000 0.666312 5.166667 0.048304 0.160205 0.000000 0.666312 5.250000 0.048304 0.161815 0.000000 0.666312 5.333333 0.048304 0.163425 0.000000 0.666312 5.416667 0.048304 0.165035 0.000000 0.666312 END FTABLE 1 FTABLE 2 66 5 Depth Area Volume Outflow1 Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.015696 0.000000 0.000000 0.000000 18005-B-wwhm 3/9/2019 6:34:46 AM Page 52 A-53 0.083333 0.015696 0.000523 0.000000 0.266000 0.166667 0.015696 0.001046 0.000000 0.266000 0.250000 0.015696 0.001569 0.000000 0.266000 0.333333 0.015696 0.002093 0.000000 0.266000 0.416667 0.015696 0.002616 0.000000 0.266000 0.500000 0.015696 0.003139 0.000000 0.266000 0.583333 0.015696 0.003662 0.000000 0.266000 0.666667 0.015696 0.004185 0.000000 0.266000 0.750000 0.015696 0.004709 0.000000 0.266000 0.833333 0.015696 0.005844 0.000000 0.266000 0.916667 0.015696 0.006973 0.000000 0.266000 1.000000 0.015696 0.008097 0.000000 0.266000 1.083333 0.015696 0.009219 0.000000 0.266000 1.166667 0.015696 0.010336 0.000000 0.266000 1.250000 0.015696 0.011447 0.000000 0.266000 1.333333 0.015696 0.012559 0.000000 0.266000 1.416667 0.015696 0.013662 0.000000 0.266000 1.500000 0.015696 0.014762 0.000000 0.266000 1.583333 0.015696 0.015856 0.000000 0.266000 1.666667 0.015696 0.016945 0.000000 0.266000 1.750000 0.015696 0.018029 0.000000 0.266000 1.833333 0.015696 0.019107 0.000000 0.266000 1.916667 0.015696 0.020179 0.000000 0.266000 2.000000 0.015696 0.021244 0.000000 0.266000 2.083333 0.015696 0.022303 0.000000 0.266000 2.166667 0.015696 0.023355 0.000000 0.266000 2.250000 0.015696 0.024399 0.000000 0.266000 2.333333 0.015696 0.025435 0.000000 0.266000 2.416667 0.015696 0.026464 0.000000 0.266000 2.500000 0.015696 0.027484 0.000000 0.266000 2.583333 0.015696 0.028494 0.000000 0.266000 2.666667 0.015696 0.029495 0.000000 0.266000 2.750000 0.015696 0.030486 0.000000 0.266000 2.833333 0.015696 0.031467 0.000000 0.266000 2.916667 0.015696 0.032436 0.000000 0.266000 3.000000 0.015696 0.033394 0.000000 0.266000 3.083333 0.015696 0.034338 0.000000 0.266000 3.166667 0.015696 0.035272 0.000000 0.266000 3.250000 0.015696 0.036192 0.000000 0.266000 3.333333 0.015696 0.037098 0.000000 0.266000 3.416667 0.015696 0.037984 0.000000 0.266000 3.500000 0.015696 0.038858 0.000000 0.266000 3.583333 0.015696 0.039713 0.000000 0.266000 3.666667 0.015696 0.040550 0.000000 0.266000 3.750000 0.015696 0.041361 0.000000 0.266000 3.833333 0.015696 0.042153 0.000000 0.266000 3.916667 0.015696 0.042919 0.000000 0.266000 4.000000 0.015696 0.043656 0.000000 0.266000 4.083333 0.015696 0.044351 0.000000 0.266000 4.166667 0.015696 0.044993 0.000000 0.266000 4.250000 0.015696 0.045586 0.000000 0.266000 4.333333 0.015696 0.046160 0.000000 0.266000 4.416667 0.015696 0.046716 0.000000 0.266000 4.500000 0.015696 0.047249 0.000000 0.266000 4.583333 0.015696 0.047824 0.000000 0.266000 4.666667 0.015696 0.048347 0.000000 0.266000 4.750000 0.015696 0.048871 0.000000 0.266000 4.833333 0.015696 0.049393 0.000000 0.266000 4.916667 0.015696 0.049917 0.000000 0.266000 5.000000 0.015696 0.050440 0.000000 0.266000 5.083333 0.015696 0.050963 0.000000 0.266000 5.166667 0.015696 0.051486 0.000000 0.266000 5.250000 0.015696 0.052009 0.000000 0.266000 5.333333 0.015696 0.052533 0.000000 0.266000 5.416667 0.015696 0.053056 0.000000 0.266000 END FTABLE 2 END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** 18005-B-wwhm 3/9/2019 6:34:46 AM Page 53 A-54 <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1.2 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1.2 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1008 FLOW ENGL REPL RCHRES 1 HYDR O 1 1 1 WDM 1009 FLOW ENGL REPL RCHRES 1 HYDR O 2 1 1 WDM 1010 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1011 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL COPY 3 OUTPUT MEAN 1 1 48.4 WDM 703 FLOW ENGL REPL COPY 503 OUTPUT MEAN 1 1 48.4 WDM 803 FLOW ENGL REPL RCHRES 2 HYDR RO 1 1 1 WDM 1012 FLOW ENGL REPL RCHRES 2 HYDR O 1 1 1 WDM 1013 FLOW ENGL REPL RCHRES 2 HYDR O 2 1 1 WDM 1014 FLOW ENGL REPL RCHRES 2 HYDR STAGE 1 1 1 WDM 1015 STAG ENGL REPL COPY 2 OUTPUT MEAN 1 1 48.4 WDM 702 FLOW ENGL REPL COPY 502 OUTPUT MEAN 1 1 48.4 WDM 802 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2 MASS-LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3 MASS-LINK 5 IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5 MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 MASS-LINK 17 RCHRES OFLOW OVOL 1 COPY INPUT MEAN END MASS-LINK 17 END MASS-LINK END RUN 18005-B-wwhm 3/9/2019 6:34:46 AM Page 54 A-55 Predeveloped HSPF Message File 18005-B-wwhm 3/9/2019 6:34:46 AM Page 55 A-56 Mitigated HSPF Message File ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 10:30 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7118.8 7188.9 7205.6 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 10:30 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -5.209E+03 1.2379 1.2379E+00 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 10:45 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7531.2 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 10:45 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -2.475E+04 5.8802 5.8801E+00 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11: 0 RCHRES: 1 18005-B-wwhm 3/9/2019 6:34:46 AM Page 56 A-57 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8012.9 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11: 0 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -5.365E+04 12.749 1.2749E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11:15 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8312.5 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11:15 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -7.163E+04 17.021 1.7021E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11:30 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8488.2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 57 A-58 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11:30 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -8.217E+04 19.527 1.9527E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 11:45 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8344.7 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 11:45 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -7.356E+04 17.480 1.7480E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12: 0 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 8222.9 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12: 0 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). 18005-B-wwhm 3/9/2019 6:34:46 AM Page 58 A-59 Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -6.625E+04 15.743 1.5743E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12:15 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7975.0 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12:15 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -5.138E+04 12.208 1.2208E+01 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12:30 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7621.2 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12:30 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -3.015E+04 7.1645 7.1645E+00 2 ERROR/WARNING ID: 341 6 DATE/TIME: 1960/10/23 12:45 18005-B-wwhm 3/9/2019 6:34:46 AM Page 59 A-60 RCHRES: 1 The volume of water in this reach/mixed reservoir is greater than the value in the "volume" column of the last row of RCHTAB(). To continue the simulation the table has been extrapolated, based on information contained in the last two rows. This will usually result in some loss of accuracy. If depth is being calculated it will also cause an error condition. Relevant data are: NROWS V1 V2 VOL 66 7.1188E+03 7188.9 7199.7 ERROR/WARNING ID: 341 5 DATE/TIME: 1960/10/23 12:45 RCHRES: 1 Calculation of relative depth, using Newton's method of successive approximations, converged to an invalid value (not in range 0.0 to 1.0). Probably ftable was extrapolated. If extrapolation was small, no problem. Remedy; extend ftable. Relevant data are: A B C RDEP1 RDEP2 COUNT 0.0000E+00 4208.2 -4.857E+03 1.1541 1.1541E+00 2 18005-B-wwhm 3/9/2019 6:34:46 AM Page 60 A-61 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright Â© by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com 18005-B-wwhm 3/9/2019 6:34:46 AM Page 61 A-62 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX B â€“ INFILTRATION STUDY AND GEOTECHNICAL REPORT B-1 SONDERGAARD GEOSCIENCE, PLLC 13012 65TH Avenue SE Snohomish, Washington 98296 April 24, 2018 Project No. J-0045 Gayteway LLC P.O. Box 1727 Bellevue, WA 98009 Attention: Chris Gayte Subject: Soil Infiltration Rate Building B and C Gayteway Business Park 20015 67th Avenue NE Arlington, Washington Dear Mr. Gayte: As requested, Sondergaard Geosciences, PLLC (SGP) is pleased to present our recommendations for soil infiltration rate for the subject site. This study has been prepared for the exclusive use of Gayteway LLC and their agents, for specific application to this project. Within the limitations of scope and schedule, our services have been performed in accordance with generally accepted engineering geology practices in effect in this area at the time our study was prepared. No other warranty, express or implied, is made. SITE AND PROJECT DESCRIPTION The subject property consists of an irregularly-shaped parcel (Snohomish County Parcel Number 31051400200700), with a combined area of approximately 54 acres located at 20015 67th Avenue NE in Arlington, Washington (Figure 1). The subject property is bounded to the east, south and north by commercial/industrial development and to the west by 67th Avenue NE. The proposed project that is the subject of this report is located on the northwest portion of the property fronting 67th Avenue NE. At the project site, overall site topography is relative flat. The subject site formerly was occupied by a lumber mill that has since be demolished. The project site is clear of vegetation Based on our discussions with you, we understand that plans for the current project include the construction of two concrete tilt-up structures; one totaling approximately 65,950 square feet (Building B) and one totaling approximately 66,100 square feet( Building C). April 24, 2018 SONDERGARRD GEOSCIENCES, PLLC 1 B-2 Gayteway Business Park Buildings B and C Soil Infiltration Rate Arlington, Washington SUBSURFACE EXPLORATION Twelve exploration pits were completed at the site by SGP on January 22, 2018. The exploration pits were continuously observed and logged by an engineering geologist. Descriptions of the soils encountered at the site are provided below. Fill Crushed Rock Fill Fill consisting of loose to medium dense, moist, tan crushed rock (1/2-minus) was encountered in exploration pits EP-5 and EP-6. The crushed rock fill was generally found at the surface to depths of approximately 1 to 4 feet at these locations. This material is suitable for reuse as structural fill if properly compacted. Wood Fill Fill typically consisting of loose, moist, dark brown, sand with wood fragments and soft, moist dark brown woodchips, dimensional lumber and small logs was encountered in exploration pits EP-1, EP-2, EP-3, EP-4, EP-5, EP-6 and EP-11. The wood fill was typically found at the surface to depths ranging from approximately 2 to 8 feet. Wood fill was also encountered in the recent soil sampling excavation I-6 from just below the pavement to a depth of approximately 6 feet. Six to eight-inch diameter logs were encountered in soil sampling excavation I-3 at a depth of about 4 feet. Recessional Outwash Recessional outwash soils were encountered underlying the fills to the full depths explored depths of approximately 9 to 14 feet below the existing ground surface. This soil generally consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. Ground Water Ground water seepage was not encountered in the exploration pits advanced for this report in January 2018 with the exception of exploration EP-9. Exploration pit EP-9 exhibited slow ground water seepage at a depth of about 6.5 feet. It should be noted that the depth and occurrence of ground water seepage at the site likely varies in response to such factors as changes in season, amount of precipitation, location, and site use. SGP returned to the site on to collect soil samples for grain size analyses at six planned infiltration locations and depths (Figure 1) identified by the project civil engineer. Ground April 24, 2018 SONDERGARRD GEOSCIENCES, PLLC 2 B-3 Gayteway Business Park Buildings B and C Soil Infiltration Rate Arlington, Washington water was not encountered at the time of excavation in April 2018 at sample locations I-1, I-2, I- 4 and I-5. Slow to moderate ground water seepage was observed at sample location I-3 at a depth of about 4 feet and I-6 at a depth of about 8 feet. At the depths specified, all infiltration would be into the granular recessional outwash deposits. Infiltration We understand that the on-site infiltration of site generated storm water is the preferred method for the disposal of storm water. Because the soils underlying the site consist of unconsolidated recessional outwash, the methods outlined in the January 2016 Snohomish County Drainage Manual, Volume III, Section 3.3.6 Soil Grain Size Analysis Method were used to determine the soil infiltration rate. The recommended uncorrected infiltration rates based upon grain size analyses of soil samples collected at each proposed infiltration location and performed in accordance with ASTM Method D422 are presented in Table 1 below: Table 1. Soil Infiltration Rate Sample No. Depth (ft) Ksat (cm/sec) Uncorrected Infiltration Rate (in/hr) I-1 9 6.91 x 10-2 98 I-2 7 2.67 x 10-2 38 I-3 7 9.4 x 10-2 133 I-4 9 6.53 x 10-2 93 I-5 9 4.0 x 10-1 568 I-6 7 4.29 x 10-2 61 Excluding location I-5 and averaging the results from the remaining five locations results in an average uncorrected soil infiltration rate of 85 inches per hour. The infiltration rates presented above are uncorrected and do not contain factors of safety. April 24, 2018 SONDERGARRD GEOSCIENCES, PLLC 3 B-4 B-5 SITE AREA 408,000 SF (9.36 ACRES) BUILDING AREA 105,000 SF BUILDING B 17 100 SF BUILDING C --n 122,100 SF TOTAL I-6 1 PARKING: â–¡111111111111111 PARKING LOT A ï¿½ 180 STALLS PROVIDED PARKING LOT A -----+-1==------ BUILDING B 011111111111111 ï¿½ 115 STALLS PROVIDED 180 STALLS BUILDING C â–¡1111111111111ï¿½ 63 STALLS PROVIDED TOTAL SITE 358 TOTAL STALLS PROVIDED 01111111111110 I-3 7 175'-0" J I 1 i I J I-5 I-5 Sample Number and I Approximate Location 1 'b i ï¿½ I ï¿½ J BUILDING B 105,000 SF I 1 'b i I I 0 0 c.o w z w ::::> z I-2 ï¿½ I-4 7 b J I 0 76'-5" 180'-0" 'b I-1 BUILDING C I 17,100 SF rn o 111111111n111111110 NORTH INFILTRATION SOIL SAMPLE LOCATIONS GAYTEWAY BUSINESS PARK ARLINGTON, WASHINGTON $ 1' = 100' J-0045 FIGURE 1 GA YTEWAY BUSINESS PARK - SITE PLAN cï¿½ ARLINGTON, WASHINGTON GA YTEW A Y LLC. a r C h I t e C t s 04/04/18 B-6 Particle Size Distribution Report in. Â½ in. in. 6 in. 3 in. 2 in.1 1 in.Â¾ Â½ 3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 0.0 0.6 1.6 63.9 32.1 1.8 TEST RESULTS Material Description Opening Percent Spec.* Pass? SAND, trace silt, trace sand Size Finer (Percent) (X=Fail) 1.5 100.0 1 100.0 Atterberg Limits (ASTM D 4318) .75 100.0 PL= NP LL= NV PI= NP .375 100.0 #4 99.4 Classification USCS (D 2487)= SP AASHTO (M 145)= A-1-b #8 98.3 #10 97.8 Coefficients #20 86.1 D90= 1.0305 D85= 0.8336 D60= 0.5925 #40 33.9 D50= 0.5254 D30= 0.3998 D15= 0.2863 #60 11.2 D10= 0.2377 Cu= 2.49 Cc= 1.14 #100 3.5 #200 1.8 Remarks #270 1.6 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: Bn Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-1 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-7 Particle Size Distribution Report in. Â½ in. in. 6 in. 3 in. 2 in.1 1 in.Â¾ Â½ 3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 12.6 23.4 10.4 27.0 20.8 5.8 TEST RESULTS Material Description Opening Percent Spec.* Pass? very gravelly, SAND, some silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 94.1 Atterberg Limits (ASTM D 4318) .75 87.4 PL= Np LL= NV PI= .375 74.4 #4 64.0 Classification USCS (D 2487)= SP-SM AASHTO (M 145)= A-1-b #8 55.3 #10 53.6 Coefficients #20 43.2 D90= 21.2237 D85= 17.1115 D60= 3.5036 #40 26.6 D50= 1.3947 D30= 0.4838 D15= 0.2545 #60 14.7 D10= 0.1705 Cu= 20.55 Cc= 0.39 #100 9.0 #200 5.8 Remarks #270 5.0 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-2 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-8 Particle Size Distribution Report in. Â½ in. in. 6 in. 3 in. 2 in.1 1 in.Â¾ Â½ 3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 19.2 35.5 13.3 22.2 7.6 2.2 TEST RESULTS Material Description Opening Percent Spec.* Pass? very sandy, GRAVEL, trace silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 86.1 Atterberg Limits (ASTM D 4318) .75 80.8 PL= NP LL= NV PI= NP .375 59.4 #4 45.3 Classification USCS (D 2487)= GP AASHTO (M 145)= A-1-a #8 34.4 #10 32.0 Coefficients #20 20.5 D90= 29.1512 D85= 24.0878 D60= 9.7280 #40 9.8 D50= 6.3283 D30= 1.7297 D15= 0.6026 #60 4.8 D10= 0.4327 Cu= 22.48 Cc= 0.71 #100 3.0 #200 2.2 Remarks #270 2.1 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-3 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-9 Particle Size Distribution Report in. Â½ in. in. 6 in. 3 in. 2 in.1 1 in.Â¾ Â½ 3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 16.1 20.9 12.9 38.7 8.7 2.7 TEST RESULTS Material Description Opening Percent Spec.* Pass? very gravelly, SAND, trace silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 90.0 Atterberg Limits (ASTM D 4318) .75 83.9 PL= NP LL= NV PI= .375 73.2 #4 63.0 Classification USCS (D 2487)= SP AASHTO (M 145)= A-1-a #8 52.9 #10 50.1 Coefficients #20 22.2 D90= 25.4438 D85= 20.1425 D60= 3.8522 #40 11.4 D50= 1.9933 D30= 1.0813 D15= 0.5849 #60 5.9 D10= 0.3757 Cu= 10.25 Cc= 0.81 #100 3.6 #200 2.7 Remarks #270 2.6 Collected: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-4 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-10 Particle Size Distribution Report in. Â½ in. in. 6 in. 3 in. 2 in.1 1 in.Â¾ Â½ 3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 37.5 27.0 12.9 17.0 4.0 1.6 TEST RESULTS Material Description Opening Percent Spec.* Pass? very sandy, GRAVEL, trace silt Size Finer (Percent) (X=Fail) 2 100.0 1.5 96.2 Atterberg Limits (ASTM D 4318) 1 73.7 PL= NP LL= NV PI= .75 62.5 .375 47.5 Classification USCS (D 2487)= GP AASHTO (M 145)= A-1-a #4 35.5 #8 24.9 Coefficients #10 22.6 D90= 33.3680 D85= 30.6805 D60= 17.4510 #20 11.7 D50= 10.9814 D30= 3.3420 D15= 1.1264 #40 5.6 D10= 0.7254 Cu= 24.06 Cc= 0.88 #60 3.3 #100 2.2 Remarks #200 1.6 Collected by: Jon Sondergaard #270 1.4 Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-5 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-11 Particle Size Distribution Report in. Â½ in. in. 6 in. 3 in. 2 in.1 1 in.Â¾ Â½ 3/8 in. #4 #10 #20#30#40 #60 #100#140#200 100 90 80 70 60 50 40 PERCENT FINER 30 20 10 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. % Gravel % Sand % Fines % +3" Coarse Fine Coarse Medium Fine Silt Clay 0.0 1.0 30.3 15.9 32.9 13.6 6.3 TEST RESULTS Material Description Opening Percent Spec.* Pass? very gravelly, SAND, some silt Size Finer (Percent) (X=Fail) 1.5 100.0 1 100.0 Atterberg Limits (ASTM D 4318) .75 99.0 PL= NP LL= NV PI= .375 89.2 #4 68.7 Classification USCS (D 2487)= SP-SM AASHTO (M 145)= A-1-b #8 55.7 #10 52.8 Coefficients #20 36.9 D90= 9.8529 D85= 8.1746 D60= 3.0792 #40 19.9 D50= 1.6952 D30= 0.6420 D15= 0.3287 #60 11.3 D10= 0.2187 Cu= 14.08 Cc= 0.61 #100 7.7 #200 6.3 Remarks #270 6.1 Collected by: Jon Sondergaard Date Received: 04/13/2018 Date Tested: 04/20/2018 Tested By: BN Checked By: MM Title: * (no specification provided) Location: Onsite Date Sampled: 04/12/2018 Sample Number: I-6 Client: GS Venture Partners Project: Gayteway Business Park Project No: 150563 E001 Figure B-12 SONDERGAARD GEOSCIENCE, PLLC 13012 65TH Avenue SE Snohomish, Washington 98296 February 9, 2018 Project No. J-0045 Gayteway LLC P.O. Box 1727 Bellevue, WA 98009 Attention: Chris Gayte Subject: Geotechnical Engineering Study Building B and C Gayteway Business Park 20015 67th Avenue NE Arlington, Washington Dear Mr. Gayte: As requested, Sondergaard Geosciences, PLLC (SGP) is pleased to present our geotechnical engineering study for the subject site. This study has been prepared for the exclusive use of Gayteway LLC and their agents, for specific application to this project. Within the limitations of scope and schedule, our services have been performed in accordance with generally accepted engineering geology and geotechnical engineering practices in effect in this area at the time our study was prepared. No other warranty, express or implied, is made. SITE AND PROJECT DESCRIPTION The subject property consists of an irregularly-shaped parcel (Snohomish County Parcel Number 31051400200700), with a combined area of approximately 54 acres located at 20015 67th Avenue NE in Arlington, Washington (Figure 1). The subject property is bounded to the east, south and north by commercial/industrial development and to the west by 67th Avenue NE. The proposed project that is the subject of this report is located on the northwest portion of the property fronting 67th Avenue NE. At the project site, overall site topography is relative flat. The subject site formerly was occupied by a lumber mill that has since be demolished. The project site is clear of vegetation Based on our discussions with you, we understand that current plans for the current project include the construction of two concrete tilt-up structures; one totaling approximately 65,950 square feet (Building B) and one totaling approximately 66,100 square feet. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 1 B-13 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington SUBSURFACE EXPLORATION Twelve exploration pits were completed at the site by SGP on January 22, 2018. The approximate locations of the explorations are shown on the attached Site Plan Figure 2. The exploration pits were completed on the property using an excavator provided by the owner and were continuously observed and logged by an engineering geologist. Logs of the exploration pits are attached to this report. Descriptions of the soils encountered at the site are provided below. Fill Crushed Rock Fill Fill consisting of loose to medium dense, moist, tan crushed rock (1/2-minus) was encountered in exploration pits EP-5 and EP-6. The crushed rock fill was generally found at the surface to depths of approximately 1 to 4 feet at these locations. This material is suitable for reuse as structural fill if properly compacted. Wood Fill Fill typically consisting of loose, moist, dark brown, sand with wood fragments and soft, moist dark brown woodchips, dimensional lumber and small logs was encountered in exploration pits EP-1, EP-2, EP-3, EP-4, EP-5, EP-6 and EP-11. The wood fill was typically found at the surface to depths ranging from approximately 2 to 8 feet. The approximate thickness of the wood fill is shown on Figure 2. This material is not suitable for the support of foundations, floor slabs or pavements. Recessional Outwash Recessional outwash soils were encountered underlying the fills to the full depths explored depths of approximately 9 to 12 feet below the existing ground surface. This soil generally consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. This unit is suitable for support of foundations, slabs and pavements when properly compacted as recommended in this report. Ground Water Ground water seepage was not encountered in the exploration pits advanced for this report in January 2018 with the exception of exploration EP-9. Exploration pit EP-9 exhibited slow ground water seepage at a depth of about 6.5 feet. It should be noted that the depth and February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 2 B-14 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington occurrence of ground water seepage at the site likely varies in response to such factors as changes in season, amount of precipitation, location, and site use. GEOLOLGIC HAZARDS The following discussion of applicable geologic hazards is based on review of the City of Arlington Municipal Code (AMC) and the geologic, topographic, and ground and surface water conditions as observed and discussed herein. The discussion will be limited to landslide and steep slope hazards, seismic hazards, and erosion hazards. Slope Hazards and Mitigations The site is characterized by flat, generally gentle topography. In our opinion, the site does not meet the criteria of a Landslide Hazard Area according to AMC Part IV Section 20.93.600(b)(2). Seismic Hazards and Mitigations Seismic Hazard Area Ground water was not encountered in the site explorations completed to maximum depth of about 12 feet below the existing site grade. Review of well logs on file at the Washington State Department of Ecology indicates that the shallowest ground water in the vicinity of the site occurs at depths of about 30 to 50 feet below the ground surface and that soils below this depth typically consist of clay and silt. In our opinion, the subsurface conditions at the project site do not meet the definition in AMC Part IV Section 20.93.600(b)(4) for a Seismic Hazard Area due to the depth to the shallowest ground water and the density and fine-grained nature of the soils at and below that depth. However, earthquakes occur in the Puget Lowland with great regularity. The majority of these events are small and are usually not felt by people. However, large earthquakes do occur, as evidenced by the 1949, 7.2-magnitude event; the 1965, 6.5-magnitude event; and the 2001, 6.8-magnitude event. The 1949 earthquake appears to have been the largest in this area during recorded history. Evaluation of return rates indicates that an earthquake of the magnitude between 5.5 and 6.0 is likely within a given 20- to 40-year period. Generally, there are four types of potential hazards associated with large seismic events: 1) surficial ground rupture, 2) seismically induced landslides, 3) liquefaction, and 4) ground motion. The potential for each of these hazards to adversely impact the proposed project is discussed below. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 3 B-15 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington Surficial Ground Rupture The project site is located approximately 16 miles southwest of the Devilâ€™s Mountain Fault Zone. This fault systems in has been hypothesized to have a reoccurrence interval in excess of several thousand years. Due to the suspected long recurrence interval and distance from the subject site, the potential for surficial ground rupture is considered to be low during the expected life of the proposed development. No mitigation efforts beyond complying with the requirements of the local jurisdictions and the current International Building Code (IBC) are recommended for this site. Seismically Induced Landslides The potential risk of damage to the proposed structures by seismically induced land sliding is low due to the gentle topography and lack of ground water seepage on the project site, in our opinion. Liquefaction Liquefaction is the process of loose, saturated sand losing its internal shear strength when subjected to cyclic loading, as may occur during an earthquake. Due to the lack of a shallow ground water table at the site and the density and fine-grained nature of soils below the ground water at depth, the potential for liquefaction to occur is low, in our opinion. Ground Motion It is our opinion that earthquake damage to the proposed structures, when founded on suitable bearing strata in accordance with the recommendations contained herein, will likely be caused by the intensity and acceleration associated with the event. Structural design for the project should follow current IBC standards. The 2015 IBC defines Site Classification by reference to Table 20.3.-1 of the American Society of Civil Engineers publication ASCE 7, the current version of which is ASCE 7-10. In our opinion the subsurface conditions at the site are consistent with a Site Classification of â€œDâ€ as defined in the referenced documents. Erosion Hazards and Mitigations The subject property does not meet the criteria for an erosion hazard area as defined in AMC Part IV Section 20.93.600(b)(1). The following discussion addresses potential erosion hazards that could develop during construction. The most effective erosion control measure is the maintenance of adequate ground cover. Maintaining cover measures atop disturbed ground provides the greatest reduction to the February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 4 B-16 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington potential generation of turbid runoff and sediment transport. During the local wet season (October 1 through March 31), exposed soil should not remain uncovered for more than 2 days unless it is actively being worked. Ground-cover measures can include erosion control matting, plastic sheeting, straw mulch, crushed rock or recycled concrete, or mature hydroseed. Some fine-grained surface soils are the result of natural weathering processes that have broken down parent materials into their mineral components. These mineral components can have an inherent electrical charge. Electrically charged mineral fines attract oppositely charged particles and can combine (flocculate) to form larger particles that will settle out of suspension. The sediments produced during the recent glaciation of Puget Sound are, however, most commonly the suspended soils that are carried by site storm water. The fine-grained fraction of the glacially derived soil is referred to as â€œrock flour,â€ which is primarily a silt-sized particle with no electrical charge. These particles, once suspended in water, may have settling times in periods of months. Therefore, the flow length within a temporary sediment control trap or pond has virtually no effect on the water quality of the discharge, since silt will not settle out of suspension in the time it takes to flow from one end of the pond to the other. Reduction of turbidity from a construction site is almost entirely a function of cover measures and flow control. Temporary sediment traps and ponds are necessary to control the release rate of the runoff and to provide a catchment for sand-sized and larger soil particles, but are very ineffective at reducing the turbidity of the runoff. To mitigate the erosion hazards and potential for off-site sediment transport, we recommend the following: 1) The winter performance of a site is dependent on a well-conceived plan for control of site erosion and storm water runoff. It is easier to keep the soil on the ground than to remove it from storm water. The owner and the design team should include adequate ground-cover measures, access roads, and staging areas in the project bid to give the selected contractor a workable site. The selected contractor needs to be prepared to implement and maintain the required measures to reduce the amount of exposed ground. A site maintenance plan should be in place in the event storm water turbidity measurements are greater than the City of Seattle standards. 2) All TESC measures for a given area to be graded or otherwise worked should be installed prior to any activity within that area. The recommended sequence of construction within a given area would be to install sediment traps and/or ponds and establish perimeter flow control prior to starting mass grading. 3) During the wetter months of the year, or when large storm events are predicted during the summer months, each work area should be stabilized so that if showers occur, the February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 5 B-17 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington work area can receive the rainfall without excessive erosion or sediment transport. The required measures for an area to be â€œbuttoned-upâ€ will depend on the time of year and the duration the area will be left un-worked. During the winter months, areas that are to be left un-worked for more than 2 days should be mulched or covered with plastic. During the summer months, stabilization will usually consist of seal-rolling the subgrade. Such measures will aid in the contractorâ€™s ability to get back into a work area after a storm event. The stabilization process also includes establishing temporary storm water conveyance channels through work areas to route runoff to the approved treatment facilities. 4) All disturbed areas should be revegetated as soon as possible. If it is outside of the growing season, the disturbed areas should be covered with mulch, as recommended in the erosion control plan. Straw mulch provides the most cost-effective cover measure and can be made wind-resistant with the application of a tackifier after it is placed. 5) Surface runoff and discharge should be controlled during and following development. Uncontrolled discharge may promote erosion and sediment transport. Under no circumstances should concentrated discharges be allowed to flow over significant slopes. 6) Soils that are to be reused around the site should be stored in such a manner as to reduce erosion from the stockpile. Protective measures may include, but are not limited to, covering with plastic sheeting, the use of low stockpiles in flat areas, or the use of straw bales/silt fences around pile perimeters. During the period between October 1 and March 31, these measures are required. 7) On-site erosion control inspections and turbidity monitoring should be performed in accordance with City of Seattle requirements. Weekly and monthly reporting to Ecology should be performed on a regularly scheduled basis. TESC monitoring should be part of the weekly construction team meetings. Temporary and permanent erosion control and drainage measures should be adjusted and maintained, as necessary, at the time of construction. It is our opinion that with the proper implementation of the TESC plans and by field-adjusting appropriate mitigation elements (best management practices) during construction, as recommended by the erosion control inspector, the potential adverse impacts from erosion hazards on the project during construction can be mitigated. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 6 B-18 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington GEOTECHNICAL ENGINEERING RECOMMENDATIONS The medium dense Vashon recessional outwash encountered in the exploration pits is suitable for foundation support. Fill encountered within the exploration pits completed at the projectsite is not suitable for foundation. The following sections provide our recommendations for foundation support and support of slab-on-grade floors. Site Preparation Site preparation of planned structural fill pads, building foundations, and other areas should include removal of all vegetation, debris, wood fill and any other deleterious material. Areas where loose surficial soils exist due to grading/grubbing operations should be recompacted in place, or if this is not feasible due to either soil composition or moisture content, the loose soils should be removed and replaced as subsequently recommended for structural fill placement. The wood fill identified at the site and that may be encountered in other areas during grading operations should be removed from beneath all building and pavement areas. IN the exploration pits the depths of removal ranged from approximately 2 to 8 feet below the existing site grade. Areas where this material has been removed should be brought back to planned subgrade elevations with structural fill placed and compacted as described below. The existing crushed rock fill encountered in some of the explorations may be reused as structural fill if compacted to at least 95 percent of its maximum dry density as determined by ASTM D:1557. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes, however, we anticipate that temporary, unsupported cut slopes in the medium dense native sand may be made at a maximum slope of 1H:1V (Horizontal:Vertical). Additionally, if ground water seepage is observed, the temporary slopes may need to be readjusted. As is typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may have to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. Permanent cut slopes in medium dense native sediments or structural fill must not exceed a 2H:1V inclination. Fill slopes should either be overbuilt and trimmed back to final grade or surface compacted to a specified density. The native soils may be subject to disturbance when wet. The contractor must use care during site preparation and excavation operations so that the underlying soils are not softened. If disturbance occurs, the softened soils should be removed and the area brought to grade with structural fill. Consideration should be given to protecting access and staging areas with an appropriate section of crushed rock or asphalt treated base (ATB). February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 7 B-19 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington Foundation Support Conventional Spread Footings The foundation bearing stratum, consisting of either medium dense native Vashon sediments or structural fill placed over these sediments, is relatively shallow and spread footings may be used for foundation support. If needed, structural fill placed below foundation areas should consist of non-organic soil, free of deleterious materials, placed in maximum loose lift thicknesses of 8 inches with each lift compacted to at least 95 percent of the modified Proctor maximum dry density, as determined by American Society for Testing and Materials (ASTM): D 1557. Structural fill placed below footing areas should extend laterally beyond the footing edges a distance equal to or greater than the thickness of the fill. Sediments exposed in footing excavations should be compacted to a firm and unyielding condition prior to footing placement. For footings founded either directly on medium dense native Vashon outwash sediments, or on structural fill placed over these materials, we recommend that an allowable bearing pressure of 1,500 pounds per square foot (psf) be used for design purposes, including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. Perimeter footings for the proposed buildings should be buried a minimum of 18 inches into the surrounding soil for frost protection. No minimum burial depth is required for interior footings; however, all footings must penetrate to the prescribed stratum, and no footings should be founded in or above loose, organic, or existing fill soils. The area bounded by lines extending downward at 1H:1V (Horizontal:Vertical) from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM:D 1557. In addition, a 1. 5H:1V line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edges of steps or cuts in the bearing soils. All footing areas should be observed by SGP prior to placing concrete to verify that the exposed soils can support the design foundation bearing capacity and that construction conforms with the recommendations in this report. Foundation bearing verification may also be required by the governing municipality. Pipe Piles An alternative to removal of unsuitable fill soils would be the use of small diameter pipe piles for structural support of foundations or slabs. The number and spacing of the piles required February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 8 B-20 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington should be determined by a licensed structural engineer. The following table presents our recommendations for pipe pile capacities. Table 1: Small Diameter Pipe Pile Vertical Capacities Pipe Diameter (in) Pipe Schedule Hammer Size (lbs) Refusal Criteria Pipe Pile Capacity Seconds per Inch (Tons) 2 80 140 60 3 3 40 850 10 6 4 40 2,000 4 10 The pipe piles should be driven to the refusal criteria specified in Table 1 during a sustained period of continuous driving and the installation should be observed by a licensed engineer or engineering geologist. Should the pile contractor have different size/weight hammers than those specified in Table 1, different refusal criteria may apply. Resistance to lateral loads would be provided either by passive soil resistance against the existing foundation walls/footings and any new column pads/grade beams or installation of batter piles. A passive equivalent fluid pressure equal to 150 pounds per cubic foot (pcf) can be used for this purpose. All soil that is removed for pile installation and bracketing purposes must be replaced and compacted to a firm and unyielding condition. Also, all backfill around the new column pads should be placed as compacted structural fill (at least 95 percent of maximum dry density per ASTM D:1557) in order for this value to apply. We do not recommend assigning any lateral resistance to a pipe pile that is installed vertically. If batter piles are used to resist lateral loads for the new columns the lateral resistance would be equal to the horizontal component of the axial pile load. The maximum recommended batter is 1H:4V. The axial capacity of the pile is not reduced when battered at 1H:1V or less. Structural Fill Structural fill may be necessary to establish desired grades. All references to structural fill in this report refer to subgrade preparation, fill type, placement, and compaction of materials as discussed in this section. If a percentage of compaction is specified under another section of this report, the value given in that section should be used. Recycled crushed concrete that is less than 3 inches in diameter may be used for structural fill when compacted to a firm and unyielding condition as determined by the geotechnical engineer or engineering geologist. After stripping, planned excavation, and any required over-excavation have been performed to the satisfaction of the geotechnical engineer/engineering geologist, the upper 12 inches of exposed ground should be recompacted to a firm and unyielding condition. If the subgrade contains too much moisture, adequate recompaction may be difficult or impossible to obtain and should probably not be attempted. In lieu of recompaction, the area to receive fill should February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 9 B-21 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington be blanketed with washed rock or quarry spalls to act as a capillary break between the new fill and the wet subgrade. Where the exposed ground remains soft and further over-excavation is impractical, placement of an engineering stabilization fabric may be necessary to prevent contamination of the free-draining layer by silt migration from below. After recompaction of the exposed ground is approved, or a free-draining rock course is laid, structural fill may be placed to attain desired grades. Structural fill is defined as non-organic soil, acceptable to the geotechnical engineer/engineering geologist, placed in maximum 8-inch loose lifts with each lift being compacted to 95 percent of ASTM:D-1557. In the case of roadway and utility trench filling, the backfill should be placed and compacted in accordance with local codes and standards. The top of the compacted fill should extend horizontally outward a minimum distance of 3 feet beyond the location of the perimeter footings or roadway edges before sloping down at a maximum angle of 2H:1V. The contractor should note that any proposed fill soils must be evaluated by SGP prior to their use in fills. This would require that we have a sample of the material at least 72 hours in advance to perform a Proctor test and determine its field compaction standard. Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture-sensitive. Use of moisture-sensitive soil in structural fills should be limited to favorable dry weather and dry subgrade conditions. The on-site soils contained some amount of silt and are considered moisture-sensitive when excavated and used as fill materials. Construction equipment traversing the site when the soils are wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction cannot be obtained, a select import material consisting of a clean, free-draining gravel and/or sand should be used. Free-draining fill consists of non-organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction and at least 25 percent retained on the No. 4 sieve. Slab-on-Grade Floor Support Slab-on-grade floors may be constructed either directly on the undisturbed, medium dense native Vashon sediments, or on structural fill placed over these materials. Areas of the slab subgrade that are disturbed (loosened) during construction should be recompacted to an unyielding condition prior to placing the pea gravel, as described below. In order to control moisture vapor transfer through the slab, slab-on-grade floors should be constructed atop a capillary break consisting of a minimum thickness of 4 inches of washed pea gravel, washed crushed rock or other suitable material approved by the geotechnical engineer February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 10 B-22 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington or engineering geologist. The capillary break should be overlain by a 10-mil (minimum thickness) plastic vapor retarder. Foundation Walls All backfill behind foundation walls or around foundation units should be placed as per our recommendations for structural fill and as described in this section of the report. Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be designed to resist active lateral earth pressure represented by an equivalent fluid equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid of 50 pcf. Walls with sloping backfill up to a maximum gradient of 2H:1V should be designed using an equivalent fluid of 55 pcf for yielding conditions or 75 pcf for fully restrained conditions. If parking areas are adjacent to walls, a surcharge equivalent to 2 feet of soil should be added to the wall height in determining lateral design forces. As required by the 2015 IBC, retaining wall design should include a seismic surcharge pressure in addition to the equivalent fluid pressures presented above. Considering the site soils and the recommended wall backfill materials, we recommend a seismic surcharge pressure of 8H and 10H psf, where H is the wall height in feet for the â€œactiveâ€ and â€œat-restâ€ loading conditions, respectively. The seismic surcharge should be modeled as a rectangular distribution with the resultant applied at the midpoint of the walls. The lateral pressures presented above are based on the conditions of a uniform backfill consisting of excavated on-site soils, or imported structural fill compacted to 90 percent of ASTM:D 1557. A higher degree of compaction is not recommended, as this will increase the pressure acting on the walls. A lower compaction may result in settlement of the slab-on-grade or other structures supported above the walls. Thus, the compaction level is critical and must be tested by our firm during placement. Surcharges from adjacent footings or heavy construction equipment must be added to the above values. Perimeter footing drains should be provided for all retaining walls, as discussed under the â€œDrainage Considerationsâ€ section of this report. It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against the walls. This would involve installation of a minimum 1-foot-wide blanket drain to within 1 foot of finish grade for the full wall height using imported, washed gravel against the walls. Passive Resistance and Friction Factors Lateral loads can be resisted by friction between the foundation and the natural glacial soils or supporting structural fill soils, and by passive earth pressure acting on the buried portions of February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 11 B-23 Gayteway Business Park Buildings B and C Geotechnical Engineering Study Arlington, Washington the foundations. The foundations must be backfilled with structural fill and compacted to at least 95 percent of the maximum dry density to achieve the passive resistance provided below. We recommend the following allowable design parameters: â€¢ Passive equivalent fluid = 250 pcf â€¢ Coefficient of friction = 0.35 All perimeter footing walls should be provided with a drain at the base of the footing elevation. Drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set at or slightly below the bottom of the footing and the drains should be constructed with sufficient gradient to allow gravity discharge away from the buildings. Roof and surface runoff should not discharge into the footing drain system but should be handled by a separate, rigid, tightline drain. In planning, exterior grades adjacent to foundations should be sloped downward away from the structures to achieve surface drainage. Drainage Considerations All perimeter footing walls should be provided with a drain at the base of the footing elevation. Drains should consist of rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by washed pea gravel. The level of the perforations in the pipe should be set at or slightly below the bottom of the footing and the drains should be constructed with sufficient gradient to allow gravity discharge away from the buildings. Roof and surface runoff should not discharge into the footing drain system but should be handled by a separate, rigid, tightline drain. In planning, exterior grades adjacent to foundations should be sloped downward away from the structures to achieve surface drainage. PROJECT DESIGN AND CONSTRUCTION MONITORING Our report is based on a general project concept provided by the owner. We recommend that SGP be allowed to review this report and update it as needed when a more detailed project plan has been developed. In this way, we can confirm that our earthwork and foundation recommendations have been properly interpreted and implemented in the design. This review is not included in our current scope of work and budget. We are also available to provide geotechnical recommendations in the event that variations in subsurface conditions become apparent and earthwork monitoring services during construction. The integrity of the foundation system depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the services are not part of this current scope of work. If these services are desired, please let us know, and we will prepare a cost proposal. February 9, 2018 SONDERGARRD GEOSCIENCES, PLLC 12 B-24 B-25 1 J-0045 FIGURE PARK MAP WASHINGTON BUSINESS SITE VICINITY GAYTEWAY ARLINGTON, B-26 SITE AREA 79,102 SF ( 1.8 ACRES) STORAGE YARD "A' SITE AREA 142,510 SF (3.3 ACRES) BUILDING B SITE AREA 186,210 SF ( 4.3 ACRES) BUILDING C SITE AREA 408,000 SF (9.3 ACRES) TOTAL SITE AREA Exploration Pit Number and 22,842 SF (.5 ACRES) PROPOSED EASEMENT OVER RR Approximate Location EP-1 STORAGE YARD 'A' BUILDING AREA 79.102 SF 65,950 SF BUILDING "B" 2 Thickness of Wood Fill in Feet 66,100 SF BUILDING "C" D 50,660 SF WAREHOUSE 20' EASEMENT -Â D 9,003 SF RESTAURANT/TAVERN OVER RR D 2,665 SF OFFICE/STORAGE D 3,484 SF DISTILLERY n 288 SF SERVICE CORRIDOR EP-11 132,050 SF TOTAL BUILDING AREA ON SITE 6 ZONE GI GENERAL INDUSTRIAL EP-10 PARKING= BUILDING B 25 STALLS -( 15%) 9,892.5 SF OFFICE @ 1 / 400 EP-12 29 STALLS - (85%) 56,057.5 SF WHSE @ 1 /2,000 54 TOTAL STALLS REQUIRED BUILDING 'B' EP-9 65950 S 58 STALLS PROVIDED ,___I----+---+ BUILDING C 19 STALLS-(15%) 7,599 SF OFFICE @ 1/400 22 STALLS - (85%) 43,061 SF WHSE @ 1 /2,000 37 STALLS - 9,003 SF RESTAURANT/TAVERN @ 4/1,000 + 2 STALLS - 288 SF SERVICE CORRIDOR @ 4/1,000 7 STALLS - 2,665 SF OFFICE @ 1 / 400 2 STALLS - 3.484 SF DISTILLERY @ 1 /2000 EP-8 EP-7 89 TOTAL STALLS REQUIRED 128 STALLS PROVIDED TOTAL SITE 143 TOTAL STALLS REQUIRED 186 TOTAL STALLS PROVIDED DOCK DOORS T 11 BUILDING "B" T 10 BUILDING "c" EP-6 EP-5 21 TOTAL DOCK DOORS PROVIDED 5 DRIVE-IN DOORS v 2 BUILDING "B" EP-4 V 4 BUILDING "C" 6 TOTAL DOCK DOORS PROVIDED 5 EP-3 3 EP-2 8 EP-1 2 SITE AND EXPLORATION PLAN (l 111111111 n I I I I I I I IC) GAYTEWAY BUSINESS PARK 30' PRIVATE ROAD BUILDINGS B AND C ARLINGTON, WASHINGTON & $NORTH J-0045 FIGURE 2 GAYTEWAY BUSINESS PARK - BLDG. B C cï¿½ 20015 67TH AVENUE NE GA YTEW A Y LLC. ARLINGTON, WA B-27 arc h it ec ts 01I12I201a 1â€¢-soâ€¢-0â€¢ SITE AREA 408,000 SF (9.36 ACRES) BUILDING AREA 105,000 SF BUILDING B 17 100 SF BUILDING C --n 122,100 SF TOTAL I-6 1 PARKING: â–¡111111111111111 PARKING LOT A ï¿½ 180 STALLS PROVIDED PARKING LOT A -----+-1==------ BUILDING B 011111111111111 ï¿½ 115 STALLS PROVIDED 180 STALLS BUILDING C â–¡1111111111111ï¿½ 63 STALLS PROVIDED TOTAL SITE 358 TOTAL STALLS PROVIDED 01111111111110 I-3 7 175'-0" J I 1 i I J I-5 I-5 Sample Number and I Approximate Location 1 'b i ï¿½ I ï¿½ J BUILDING B 105,000 SF I 1 'b i I I 0 0 c.o w z w ::::> z I-2 ï¿½ I-4 7 b J I 0 76'-5" 180'-0" 'b I-1 BUILDING C I 17,100 SF rn o 111111111n111111110 NORTH INFILTRATION SOIL SAMPLE LOCATIONS GAYTEWAY BUSINESS PARK ARLINGTON, WASHINGTON $ 1' = 100' J-0045 FIGURE 2 GA YTEWAY BUSINESS PARK - SITE PLAN cï¿½ ARLINGTON, WASHINGTON GA YTEW A Y LLC. a r C h I t e C t s 04/04/18 B-28 EXPLORATION HOLE LOGS GAYTEWAY BUSINESS PARK BUILDINGS ARLINGTON, WASHINGTON EP-1 Depth (ft) Description FILL 0.0 â€“ 2.0 Loose, moist, dark brown, silty fine SAND with wood fragments RECESSIONAL OUTWASH 2.0 â€“ 4.0 Medium dense, moist, oxidized orange-brown, silty, SAND (Weathered). 4.0 â€“ 11.0 Medium dense, moist, brown to gray, gravelly SAND with lenses of gravel. T.D. @ 11.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-2 Depth (ft) Description FILL 0.0 â€“ 8.0 Loose, moist, brown, silty SAND with numerous wood fragments and small logs RECESSIONAL OUTWASH 8.0 â€“ 11.5 Medium dense, moist, gray, SAND with some gravel. T.D. @ 11.5 feet 1-22-18. No ground water seepage encountered. No sidewall caving. B-29 EP-3 Depth (ft) Description FILL 0.0 â€“ 3.0 Loose. Moist, brown, SAND with organics, concrete and some gravel. RECESSIONAL OUTWASH 3.0 â€“ 12.0 Medium dense, moist, brown to gray, gravelly SAND with lenses of gravel. T.D. @ 12.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-4 Depth (ft) Description FILL 0.0 â€“ 5.0 Loose, moist, dark brown, sand with wood fragments, roots and small logs. RECESSIONAL OUTWASH 5.0 -10.0 medium dense, moist, gray, sandy GRAVEL to gravelly SAND. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-5 . Depth (ft) Description FILL 0.0 â€“ 4.0 Loose, moist, tan, crushed rock FILL. RECESSIONAL OUTWASH 4.0 â€“ 9.0 Medium dense, moist, gray, gravelly SAND. T.D. @ 9.0 feet 1-22-18. No ground water seepage encountered. B-30 EP-6 Depth (ft) Description FILL 0.0 â€“ 1.0 Loose, moist, tan crushed rock F ILL. 1.0 â€“ 5.0 Soft, moist, dark brown, silty topsoil with wood fragments, roots and logs. RECESSIONAL OUTWASH 5.0 â€“ 12.0 Medium dense, moist, oxidized brown to gray, sandy GRAVEL to gravelly SAND. T.D. @ 12.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-7 . Depth (ft) Description RECESSIONAL OUTWASH 0.0 â€“ 1.5 Loose, moist, oxidized orange-brown, silty fine SAND (Weathered). 1.5 -10.0 Medium dense, moist, gray, sandy GRAVEL to gravelly SAND. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-8 Depth (ft) Description RECESSIONAL OUTWASH 0.0 â€“ 2.0 Loose, moist, oxidized orange-brown, silty fine SAND and gray sandy GRAVEL (Weathered) 2.0 â€“ 10.0 Medium dense, moist, gray, sandy GRAVEL with lenses of sand with some gravel. T.D. @ 10.0 feet. No ground water seepage encountered. No sidewall caving. B-31 EP-9 . Depth (ft) Description FILL 0.0 -4.0 Loose to medium dense, moist, brown to gray, silty SAND and gravelly SAND (Utility trench Fill). RECESSIONAL OUTWASH 4.0 â€“ 9.0 Medium dense, moist, gray, sandy GRAVEL and gravelly SAND. T.D. @ 8.0 feet 3-30-17. Slow ground water seepage at 6.5 feet. EP-10 Depth (ft) Description FILL 0.0 â€“ 1.0 Loose, moist, oxidized brown to brown, SAND with scattered organics. RECESSIONAL OUTWASH 1.0 â€“ 12.0 Medium dense, moist, brown to gray, sandy GRAVEL to gravelly SAND. T.D. @ 12.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. EP-11 Depth (ft) Description FILL 0.0 â€“ 2.0 Loose, moist, brown to gray, SAND with scattered debris 2.0 â€“ 6.0 Soft, moist, dark brown, wood chips and lumber fragments. RECESSIONAL OUTWASH 6.0 -8.0 Medium dense, moist, gray sandy GRAVEL 8.0 â€“ 10.0 Medium dense, moist, gray SAND. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving. B-32 EP-12 Depth (ft) Description FILL 0.0 â€“ 3.0 Loose, moist, brown, sandy Gravel with scattered wood fragments and log rounds RECESSIONAL OUTWASH 3.0 â€“ 10.0 Medium dense, moist, brown, sandy GRAVEL 10.0 â€“ 12.0 Medium dense, moist, gray, SAND with some gravel. T.D. @ 10.0 feet 1-22-18. No ground water seepage encountered. No sidewall caving B-33 IP-1 Ground surface elevation 141.5 feet Depth (ft) Description 0.0 â€“ 0.75 Topsoil 0.75 â€“ 3.5 Loose to medium dense, moist, oxidized brown, slightly silty to silty sand with some gravel. T.D. @ 3.5 feet 3-30-17. No ground water seepage. IP-2 Ground surface elevation 129.5 Depth (ft) Description 0.0 â€“ 0.75 Topsoil 0.75 â€“ 1.0 Loose, moist, oxidized brown, silty sand with gravel. T.D. @ 1.0 feet 3-30-17. No ground water seepage. IP-3 Ground surface elevation 137.0. Depth (ft) Description 0.0 â€“ 0.5 Topsoil 0.5 â€“ 3.0 Loose to medium dense, moist, oxidized brown, silty sand with gravel. T.D. @ 3.0 feet 3-30-17. No groundwater seepage. IP-4 Ground surface elevation at 134.5 Depth (ft) Description 0.0 â€“ 1.0 Topsoil. T.D. @ 1.0 feet. Bottom of exploration at the top of the native sand below the topsoil. No groundwater seepage. B-34 IP-5 Ground surface elevation 136.5 Depth (ft) Description 0.0 â€“ 0.75 Topsoil with abundant roots 0.75 â€“ 3.25 Loose to medium dense, gray to brown, silty sand with gravel. 3.25 â€“ 5.0 Dense, saturated, gray to brown, fine sandy silt to clayey silt. T.D. @ 3.25 feet 3-30-17. Moderate groundwater seepage at 3.25 feet. IP-6 Ground surface elevation 139.0 feet. Depth (ft) Description 0.0 â€“ 1.0 Topsoil with abundant roots. 1.0 â€“ 4.5 Medium dense, moist to saturated, gray to oxidized brown, slightly silty sand. T.D. @ 4.5 feet 3-30-17. Moderate groundwater seepage at 3.0 feet. IP-7 Ground surface elevation 141.5 feet Depth (ft) Description 0.0 â€“ 0.75 Topsoil 0.75 â€“ 4.0 Medium dense, moist to saturated, mottled gray to oxidized brown, slightly silty sand with some gravel and thin clayey silt interbeds. T.D. @ 4.0 feet. Slow groundwater seepage at 2.5 feet. IP-8 Ground surface elevation 146.5 Depth (ft) Description 0.0 â€“ 1.0 Topsoil 1.0 â€“ 3.5 Loose to medium dense, oxidized brown, slightly silty to silty, sand with some gravel. T.D. @ 3.5 feet 3-30-17. No groundwater seepage. B-35 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX C â€“ STORM OPERATION & MAINTENANCE MANUAL C-1 TERRAFORMA DES I GN GROUP STORMWATER OPERATION AND MAINTENANCE MANUAL _________________________________________________________________ GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ LOCATION: 20015 67TH AVENUE NE ARLINGTON, WA 98223 ISSUE DATE: March 5, 2019 PREPARED FOR: GAYTEWAY, LLC Contact: Chris Gayte Phone: (206) 240-9739 PREPARED BY: Terraforma Design Group, Inc. 5027 51st Avenue SW Seattle, WA 98136 TDG No. 18005 C I V I L E N G I N E E R I N G & L A N D S C A P E A R C H I T E C T U R E 5027 51st Avenue SW Seattle WA 98136 phone 206.923.0590 website www.terraformadesigngroup.com C-2 1. Introduction The proposed development consists of a new office / warehouse / manufacturing building located at 20015 67th Avenue NE. The development is located within Lot 2 of the proposed BLA for Parcels A-1 through A-4 (west side of railroad tracks) and is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. Onsite drainage improvements include new catch basins and storm drainage for surface runoff. Stormwater infiltration will be proposed for the proposed parking, landscaping and roof drainage runoff; underground infiltration chambers are proposed at this time. Runoff Treatment will be provided for the pavement areas via a Bayfilter Treatment Manhole prior to discharge to infiltration galleries. The specific purpose for the stormwater facilities is to minimize pollution that is typically associated with modern development, i.e. pollution from motor vehicles and pollution generated from erosion. This report provides guidelines to the owner for storm water facility maintenance. A copy of this manual shall be retained onsite or within reasonable access to the site (see Section 3), and shall be transferred with the property to any successors. 2. On-Site Stormwater Facility Maintenance Requirements Regular inspections of the drainage facilities should be carried on a consistent basis as provided within the maintenance guidelines included is this report. The responsible party should keep records of these inspections available for review by the governing agency. Additional inspections may be required after severe seasonal storms. Routine maintenance of the site will include mowing, care of landscaping and the removal of trash and debris from the drainage system. The parking lots and driveways should be kept clean and in repair. Events such as major storms or heavy winds will require immediate inspections for damages. 3. O&M Location, Accessibility and Responsible Organizations This Operation and Maintenance manual shall be stored within Building â€˜Bâ€™ at 20015 67th Avenue NE and shall be made available for inspection by the governing agency. Responsible Organization: GAYTEWAY, LLC Contact: Chris Gayte Phone: (206) 240-9739 C-3 4. Description of Drainage Elements The following is a list of the on-site storm drainage facilities and their function. Also attached are the required maintenance requirements for these facilities. Infiltration Trenches (Stormtech) â€“ Stormtech chamber / rock gallery allows for stormwater infiltration into the native granular soils, Catch Basins and Inlets â€“ provides runoff catchment from pavement and planter areas, Manufactured Media Filter (Bayfilter) â€“ water quality treatment 5. Maintenance Activity Log, Recordkeeping & Reports The following pages contain maintenance tables for the stormwater BMPs. The Ownerâ€™s representative or hired maintenance company shall adhere to the following maintenance guidelines and schedule. The attached checklist shall be completed by the maintenance person and filed within Appendix A. Drainage facilities shall be inspected and maintained at least annually, unless noted otherwise in the attached tables. The following keynotes explain the required frequency of a maintenance activity. â€¢ (A) Annually, once in late summer (preferably September) â€¢ (M) Monthly from October through April. â€¢ (S) Storm-based, after any major storm (use 1 inch in 24 hours as a guideline). The following tables contained shall be used as checklists. Maintenance personnel may use photocopies of these pages and check off items inspected and problems noted during each inspection. Actions taken and corrective action recommended should also be noted. This Operation and Maintenance manual shall be stored within the Chevron convenience store in the managerâ€™s office and shall be made available for inspection by the governing agency. The Ownerâ€™s representative or hired maintenance company shall submit an annual report to CITY OF TUMWATER regarding implementation of the programs referenced in (1) and (2) above. The report must be submitted on or before May 15th of each calendar year and shall contain, at a minimum, the following: (a) Name, address, and telephone number of the business, the person, or the firm responsible for plan implementation, and the person completing the report. (b) Time period covered by the report. (c) A chronological summary of activities conducted to implement the programs referenced in (1) and (2) above. A photocopy of the applicable sections of the log book with any additional explanation needed shall normally suffice. For any activities conducted by paid parties not affiliated with OWNER, include a copy of the invoice for services. (d) An outline of planned activities for the next year. C-4 C-5 INSPECTION/MAINTENANCE CHECKLIST LOCATION: LOT 2 - 20015 67TH AVENUE NE, ARLINGTON, WA 98223 STRUCTURE DATE OF INSPECTION/MAINTENANCE Results/ Maintenance Date Comments Stormtech Chambers Inspection Results Maintenance Done Catch Basins Inspection Results Maintenance Done Manufactured Media Inspection Filter / Bayfilter Results Maintenance Done Inspection Results Maintenance Done Inspection Results Maintenance Done * A COPY OF THIS MAINTENANCE LOG SHALL BE COMPLETED BY A DESIGNATED MAINTENANCE PERSON PER THE REQUIRED MAINTENANCE INTERVALS AND FILED WITHIN APPENDIX A. THESE MAINTENANCE LOGS SHALL BE KEPT ON-SITE C-6 12.0 Inspection & Maintenance STORMTECH ISOLATORâ„¢ ROW - STEP-BY-STEP 12.3 ECCENTRIC PIPE HEADER INSPECTION MAINTENANCE PROCEDURES Theses guidelines do not supercede a pipe manufac- turerâ€™s recommended I&M procedures. Consult with the Step 1) Inspect Isolator Row for sediment manufacturer of the pipe header system for specific I&M procedures. Inspection of the header system should A) Inspection ports (if present) be carried out quarterly. On sites which generate higher i. Remove lid from floor box frame levels of sediment more frequent inspections may be ii. Remove cap from inspection riser necessary. Headers may be accessed through risers, access ports or manholes. Measurement of sediment iii. Using a flashlight and stadia rod, measure may be taken with a stadia rod or similar device. Clean- depth of sediment out of sediment should occur when the sediment volume iv. If sediment is at, or above, 3" (76 mm) has reduced the storage area by 25% or the depth depth proceed to Step 2. If not proceed of sediment has reached approximately 25% of the to Step 3. diameter of the structure. B) All Isolator Rows 12.4 ECCENTRIC PIPE MANIFOLD MAINTENANCE i. Remove cover from manhole at upstream Cleanout of accumulated material should be accom- end of Isolator Row plished by vacuum pumping the material from the head- ii. Using a flashlight, inspect down Isolator er. Cleanout should be accomplished during dry weath- Row through outlet pipe er. Care should be taken to avoid flushing sediments out 1. Follow OSHA regulations for confined through the outlet pipes and into the chamber rows. space entry if entering manhole Eccentric Header Step-by-Step Maintenance 2. Mirrors on poles or cameras may be Procedures used to avoid a confined space entry 1. Locate manholes connected to the manifold system iii. If sediment is at or above the lower row of 2. Remove grates or covers sidewall holes [approximately 3" (76 mm)] 3. Using a stadia rod, measure the depth of sediment proceed to Step 2. If not proceed to Step 3. 4. If sediment is at a depth of about 25% pipe volume Step 2) Clean out Isolator Row using the JetVac process or 25% pipe diameter proceed to step 5. If not proceed to step 6. A) A fixed floor cleaning nozzle with rear 5. Vacuum pump the sediment. Do not flush sediment facing nozzle spread of 45" (1143 mm) or out inlet pipes. more is preferable 6. Replace grates and covers B) Apply multiple passes of JetVac until back- 7. Record depth and date and schedule next inspection flush water is clean C) Vacuum manhole sump as required during Figure 21 â€“ Eccentric Manifold Maintenance jetting 1, 2, 6 Step 3) Replace all caps, lids and covers Step 4) Inspect and clean catch basins and manholes upstream of the StormTech system following local guidelines. 3, 4, 5 Figure 20 â€“ StormTech Isolator Row (not to scale) 1) B) 1) A) 2 Please contact StormTechâ€™s Technical Services Department at 888-892-2894 for a spreadsheet to 4 estimate cleaning intervals. 23 Call StormTech at 860.529.8188 or 888.892.2694 or visit our website at www.stormtech.com for technical and product informC-7ation. CITY OF TUMWATER DRAINAGE DESIGN and EROSION CONTROL MANUAL Table C-13. Maintenance Checklist for Catch Basins and Inlets Drainage Systems Conditions that Shall Frequency Feature âˆš Problem Conditions to Check For Exist M,S General Trash and Trash, debris, and No trash or debris located Debris sediment in or on basin immediately in front of catch basin opening. Grate is kept clean and allows water to enter. M Sediment or debris (in the No sediment or debris in basin) that exceeds 1/3 the catch basin. Catch the depth from the bottom basin is dug out and of basin to invert of the clean. lowest pipe into or out of the basin. M,S Trash or debris in any Inlet and outlet pipes free inlet or outlet pipe of trash or debris. blocking more than 1/3 of its height. M Structural Corner of frame extends Frame is even with curb. Damage to more than 3/4 inch past Frame and/or curb face into the street Top Slab (if applicable). M Top slab has holes larger Top slab is free of holes than 2 square inches or and cracks. cracks wider than 1/4 inch (intent is to make sure no material is running into basin). M Frame not sitting flush on Frame is sitting flush on top slab, i.e., separation the riser rings or top slab of more than 3/4 inch of and firmly attached. the frame from the top slab. Frame not securely attached. A Cracks in Basin Cracks wider than Basin replaced or Walls/ Bottom 1/2 inch and longer than repaired to design 3 feet, any evidence of standards. Contact a soil particles entering professional engineer for catch basin through evaluation. cracks, or maintenance person judges that structure is unsound. A Cracks wider than No cracks more than 1/2 inch and longer than 1/4 inch wide at the joint 1 foot at the joint of any of inlet/outlet pipe. inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. C-22 Volume V â€“ Stormwater BMPs December 2009 C-8 CITY OF TUMWATER DRAINAGE DESIGN and EROSION CONTROL MANUAL Drainage Systems Conditions that Shall Frequency Feature âˆš Problem Conditions to Check For Exist A Settlement/ Basin has settled more Basin replaced or Misalignment than 1 inch or has rotated repaired to design more than 2 inches out of standards. Contact a alignment. professional engineer for evaluation. M Vegetation Vegetation growing No vegetation blocking across and blocking more opening to basin. than 10 percent of the basin opening. M Vegetation Vegetation growing in No vegetation or root inlet/outlet pipe joints that growth present. is more than 6 inches tall and less than 6 inches apart. If you are unsure whether a problem exists, please contact Tumwater and ask for technical assistance. Key: A = Annual (March or April preferred) M = Monthly (see schedule) S = After major storms December 2009 Volume V â€“ Stormwater BMPs C-23 C-9 Table V-4.5.2(15) Maintenance Standards - Manufactured Media Filters (continued) ResultsExpected Maintenance Condition When Maintenanceis Defect When Maintenance Component Needed isPerformed itswhichwould mulationon impedepermeability Media. ofthecompost media. SedimentAccu- Nosedimentdepos- Sedimentdepthexceeds6-inches mulationin itsinvaultbottomof infirstchamber. Vault firstchamber. Trashanddebris Trash/Debris Trashanddebrisaccumulatedon removedfromthe Accumulation compostfilterbed. compostfilterbed. Sedimentin Whendrainpipes,clean-outs, Drain Sedimentanddebris becomefull withsedimentand/or Pipes/Clean- removed. debris. Outs Anypartofthepipesthatare Damaged Piperepairedand/or crushedordamagedduetocor- Pipes replaced. rosionand/orsettlement. Covercannotbeopened;oneper- Coverrepairedto AccessCover soncannotopenthecoverusing properworkingspe- Damaged/Not normal liftingpressure,cor- cificationsor Working rosion/deformationofcover. replaced. Crackswiderthan1/2-inchorevid- Vaultreplacedor enceofsoil particlesenteringthe repairsmadesothat VaultStructure structurethroughthecracks,or vaultmeetsdesign Includes maintenance/inspectionpersonnel specificationsandis CracksinWall, determinethatthevaultisnotstruc-structurallysound. Bottom, turallysound. Damageto Vaultrepairedsothat Frameand/or Crackswiderthan1/2-inchatthe nocracksexistwider TopSlab jointofanyinlet/outletpipeorevid- than1/4-inchatthe enceofsoil particlesentering jointoftheinlet/outlet throughthecracks. pipe. Bafflescorroding,crackingwarp- Bafflesrepairedor ing,and/orshowingsignsoffailure Baffles replacedtospe- asdeterminedbymain- cifications. tenance/inspectionperson. 2014StormwaterManagementManual forWesternWashington C-10 VolumeV -Chapter4-Page854 Table V-4.5.2(15) Maintenance Standards - Manufactured Media Filters (continued) ResultsExpected Maintenance Condition When Maintenanceis Defect When Maintenance Component Needed isPerformed Ladderreplacedor Ladderiscorrodedordeteriorated, repairedandmeets notfunctioningproperly,not AccessLadder specifications,andis securelyattachedtostructurewall, Damaged safetouseasdeterm- missingrungs,cracks,andmis- inedbyinspection aligned. personnel. Drawdownofwaterthroughthe Mediacartridges Below Media mediatakeslongerthan1hour, replaced. GroundCart- and/oroverflow occursfrequently. ridgeType Flowsdonotproperlyenterfilter Filtercartridges ShortCircuiting cartridges. replaced. Table V-4.5.2(16) Maintenance Standards - Baffle Oil/Water Separators (API Type) ResultsExpected Maintenance Condition When Main- Defect When Maintenanceis Component tenanceisNeeded Performed Effluentdischargefrom Inspectionofdischarge vaultshouldbeclear Monitoring waterforobvioussignsof withoutthickvisible poorwaterquality. sheen. Nosedimentdeposits onvaultbottomthat Sedimentdepthinbottomof SedimentAccu- wouldimpedeflow vaultexceeds6-inchesin mulation throughthevaultand depth. reduceseparationeffi- General ciency. Trashanddebrisaccu- Trashanddebris TrashandDebris mulationinvault,orpipe removedfromvault, Accumulation inlet/outlet,floatablesand andinlet/outletpiping. non-floatables. Extractoil fromvaultby Oil accumulationsthat vactoring.Disposal in Oil Accumulation exceed1-inch,atthesurface accordancewithstate ofthewater. andlocal rulesandreg- ulations. 2014StormwaterManagementManual forWesternWashington C-11 VolumeV -Chapter4-Page855 BAYSAVE R TECHNOLOGI ES, I N C. Chapter 4 Maintenance of the BayFilterâ„¢ System The BayFilterâ„¢ system requires periodic maintenance to continue operating at the design efficiency. The maintenance process comprises the removal and replacement of each BayFilterâ„¢ cartridge and drain down module and the cleaning of the vault or manhole with a vacuum truck. BayFilterâ„¢ maintenance should be performed by a BaySaver Technologies, Inc. certified maintenance contractor. The maintenance cycle of the BayFilterâ„¢ system will be driven mostly by the actual solids load on the filter. The system should be periodically monitored to be certain it is operating correctly. Since stormwater solids loads can be variable, it is possible that the maintenance cycle could be more or less than the projected duration. The BayFilter systems in New Development applications are designed to treat the WQv in 24 hours initially. Later in the cycle these cartridges will flow at a slower rate, and when the WQv does not drain down within +/- 40 hours after the storm event, the system must be maintained. When a BayFilterâ„¢ system is first installed, it is recommended that it be inspected every six (6) months. When the filter system exhibits flows below design levels the system should be maintained. Filter cartridge replacement should also be considered when sediment levels are at or above the level of the 4 inch manifold system. Please contact the BaySaver Technologies Inc. Engineering Department for maintenance cycle estimations or assistance at 1.800.229.7283. 22 C-12 BAYSAVE R TECHNOLOGI ES, I N C. Maintenance Procedures 1. Remove the manhole covers and open all access hatches. 2. Before entering the system make sure the air is safe per OSHA Standards or use a breathing apparatus. Use low O2, high CO, or other applicable warning devices per regulatory requirements. 3. Using a vacuum truck remove any liquid and sediments that can be removed prior to entry. 4. Using a small lift or the boom of the vacuum truck, remove the used cartridges by lifting them out. 5. Any cartridges that cannot be readily lifted directly out of the vault should be removed from their location and carried to the lifting point using the Trolley system installed in the Vault (if applicable). 6. When all cartridges and drain down modules are removed, remove the balance of the solids and water; then loosen the stainless clamps on the Fernco couplings in the pipe manifold; remove the drain pipes as well. Carefully cap the manifold and the Ferncoâ€™s and rinse the floor removing the balance of the collected solids. 7. Clean the manifold pipes, inspect, and reinstall. 8. Install the exchange cartridges and close all covers. 9. The used cartridges must be sent back to BaySaver Technologies, Inc. for exchange/recycling and credit on undamaged units. 23 C-13 APPENDIX A - FILED MAINTENANCE RECORDS C-14 GAYTEWAY BUSINESS PARK â€“ BUILDING â€˜Bâ€™ STORM DRAINAGE REPORT ______________________________________________________________ APPENDIX D - CIVIL DESIGN C1.5 â€“ STORM PLAN C2.3 â€“ STORM DETAILS C2.4 â€“ STORM DETAILS ORMA F ERRA T DESIGN GROUP, INC. C1.5 INFILTRATION GALLERY 'A' - PLAN VIEW COVER PIPE CONNECTION TO END CAP WITH ADS INFILTRATION GALLERY 'A' - SECTION GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE MC-3500 CHAMBER INSTALL UNDER ISOLATOR ROW INSPECTION & MAINTENANCE (NORTH ROW) TWO LAYERS OF ADS STEP 1) INSPECT ISOLATOR ROW FOR SEDIMENT GEOSYNTHETICS 315WTM WOVEN A. INSPECTION PORTS (IF PRESENT) GEOTEXTILE BETWEEN FOUNDATION A.1. REMOVE/OPEN LID ON NYLOPLAST INLINE DRAIN STONE AND CHAMBERS. A.2. REMOVE AND CLEAN FLEXSTORM FILTER IF INSTALLED 8.3-FT MIN. WIDTH STRIPS (MC-3500). A.3. USING A FLASHLIGHT AND STADIA ROD, MEASURE DEPTH OF SEDIMENT AND RECORD ON MAINTENANCE LOG A.4. LOWER A CAMERA INTO ISOLATOR ROW FOR VISUAL INSPECTION OF SEDIMENT LEVELS (OPTIONAL) ORMA A.5. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, F PROCEED TO STEP 3. ACCEPTABLE FILL MATERIALS: STORMTECH MC-3500 CHAMBER SYSTEMS B. ALL ISOLATOR ROWS JLM JLM B.1. REMOVE COVER FROM STRUCTURE AT UPSTREAM END OF ISOLATOR AASHTO MATERIAL COMPACTION / DENSITY ROW MATERIAL LOCATION DESCRIPTION B.2. USING A FLASHLIGHT, INSPECT DOWN THE ISOLATOR ROW THROUGH CLASSIFICATIONS REQUIREMENT OUTLET PIPE FINAL FILL: FILL MATERIAL FOR LAYER 'D' STARTS i) MIRRORS ON POLES OR CAMERAS MAY BE USED TO AVOID A FROM THE TOP OF THE 'C' LAYER TO THE BOTTOM ANY SOIL/ROCK MATERIALS, NATIVE SOILS, OR PER PREPARE PER SITE DESIGN ENGINEER'S PLANS. D OF FLEXIBLE PAVEMENT OR UNPAVED FINISHED ENGINEER'S PLANS. CHECK PLANS FOR PAVEMENT N/A PAVED INSTALLATIONS MAY HAVE STRINGENT CONFINED SPACE ENTRY ERRA GRADE ABOVE. NOTE THAT PAVEMENT SUBBASE SUBGRADE REQUIREMENTS. MATERIAL AND PREPARATION REQUIREMENTS. MC-3500 TY. 2 - 54" CB ii) FOLLOW OSHA REGULATIONS FOR CONFINED SPACE ENTRY IF MAY BE PART OF THE 'D' LAYER ENTERING MANHOLE DESIGN GROUP, INC. AASHTO M145 24" (600 mm) HDPE ACCESS PIPE T BEGIN COMPACTIONS AFTER 24" (600 mm) OF 11/18/14 B.3. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, A-1, A-2-4, A-3 INITIAL FILL: FILL MATERIAL FOR LAYER 'C' GRANULAR WELL-GRADED SOIL/AGGREGATE MIXTURES, <35% MATERIAL OVER THE CHAMBERS IS REACHED. REQUIRED USE FACTORY PROCEED TO STEP 3. STARTS FROM THE TOP OF THE EMBEDMENT FINES OR PROCESSED AGGREGATE. COMPACT ADDITIONAL LAYERS IN 12" (300 mm) PRE-CORED END CAP OR C STONE ('B' LAYER) TO 24" (600 mm) ABOVE THE MAX LIFTS TO A MIN. 95% PROCTOR DENSITY FOR TOP OF THE CHAMBER. NOTE THAT PAVEMENT MOST PAVEMENT SUBBASE MATERIALS CAN BE USED IN LIEU AASHTO M43 WELL GRADED MATERIAL AND 95% RELATIVE STANDARD CROSS SECTION PART #: MC3500IEPP24BC STEP 2) CLEAN OUT ISOLATOR ROW USING THE JETVAC PROCESS SUBBASE MAY BE A PART OF THE 'C' LAYER. OF THIS LAYER. 3, 357, 4, 467, 5, 56, 57, 6, 67, 68, 7, 78, 8, 89, DENSITY FOR PROCESSED AGGREGATE A. A FIXED CULVERT CLEANING NOZZLE WITH REAR FACING SPREAD OF 45" MATERIALS. 9, 10 MC-3500 SECTION (1.1 m) OR MORE IS PREFERRED EMBEDMENT STONE: FILL SURROUNDING THE NTS B. APPLY MULTIPLE PASSES OF JETVAC UNTIL BACKFLUSH WATER IS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43 B CHAMBERS FROM THE FOUNDATION STONE ('A' DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) NO COMPACTION REQUIRED. CLEAN 3, 4 LAYER) TO THE 'C' LAYER ABOVE. ISOLATOR ROW SECTION @ CB #1 C. VACUUM STRUCTURE SUMP AS REQUIRED FOUNDATION STONE: FILL BELOW CHAMBERS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43 PLATE COMPACT OR ROLL TO ACHIEVE A FLAT A FROM THE SUBGRADE UP TO THE FOOT (BOTTOM) DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) 3, 4 STEP 3) REPLACE ALL COVERS, GRATES, FILTERS, AND LIDS; RECORD OF THE CHAMBER. OBSERVATIONS AND ACTIONS. PLEASE NOTE: 1. THE LISTED AASHTO DESIGNATIONS ARE FOR GRADATIONS ONLY. THE STONE MUST ALSO BE CLEAN, CRUSHED, ANGULAR. FOR EXAMPLE, A SPECIFICATION FOR #4 STONE WOULD STATE: "CLEAN, CRUSHED, STEP 4) INSPECT AND CLEAN BASINS AND MANHOLES UPSTREAM OF THE ANGULAR NO. 4 (AASHTO M43) STONE". 2. STORMTECH COMPACTION REQUIREMENTS ARE MET FOR 'A' LOCATION MATERIALS WHEN PLACED AND COMPACTED IN 9" (230 mm) (MAX) LIFTS USING TWO FULL COVERAGES WITH A VIBRATORY COMPACTOR. STORMTECH SYSTEM. 3. WHERE INFILTRATION SURFACES MAY BE COMPROMISED BY COMPACTION, FOR STANDARD DESIGN LOAD CONDITIONS, A FLAT SURFACE MAY BE ACHIEVED BY RAKING OR DRAGGING WITHOUT COMPACTION EQUIPMENT. FOR SPECIAL LOAD DESIGNS, CONTACT STORMTECH FOR COMPACTION REQUIREMENTS. NOTES ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE ALL PAVEMENT LAYER (DESIGNED 1. INSPECT EVERY 6 MONTHS DURING THE FIRST YEAR OF OPERATION. AROUND CLEAN, CRUSHED, ANGULAR STONE IN A & B LAYERS BY SITE DESIGN ENGINEER) ADJUST THE INSPECTION INTERVAL BASED ON PREVIOUS OBSERVATIONS OF SEDIMENT ACCUMULATION AND HIGH WATER D *TO BOTTOM OF FLEXIBLE PAVEMENT. FOR UNPAVED ELEVATIONS. PERIMETER STONE INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR, (SEE NOTE 6) C INCREASE COVER TO 30" (750 mm). 2. CONDUCT JETTING AND VACTORING ANNUALLY OR WHEN INSPECTION 12" (300 mm) MIN SHOWS THAT MAINTENANCE IS NECESSARY. B EXCAVATION WALL (CAN BE SLOPED OR VERTICAL) 45" (1140 mm) A DEPTH OF STONE TO BE DETERMINED BY DESIGN ENGINEER 9" (230 mm) MIN 6" (150 mm) MIN MC-3500 9" SUBGRADE SOILS 77" (1950 mm) 12" (300 mm) TYP END CAP (230 mm) MIN (SEE NOTE 5) NOTES: 1. MC-3500 CHAMBERS SHALL CONFORM TO THE REQUIREMENTS OF ASTM F2418 "STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 2. MC-3500 CHAMBERS SHALL BE DESIGNED IN ACCORDANCE WITH ASTM F2787 "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 3. "ACCEPTABLE FILL MATERIALS" TABLE ABOVE PROVIDES MATERIAL LOCATIONS, DESCRIPTIONS, GRADATIONS, AND COMPACTION REQUIREMENTS FOR FOUNDATION, EMBEDMENT, AND FILL MATERIALS. 4. THE "SITE DESIGN ENGINEER" REFERS TO THE ENGINEER RESPONSIBLE FOR THE DESIGN AND LAYOUT OF THE STORMTECH CHAMBERS FOR THIS PROJECT. TY. 2 - 54" CB 5. THE SITE DESIGN ENGINEER IS RESPONSIBLE FOR ASSESSING THE BEARING RESISTANCE (ALLOWABLE BEARING CAPACITY) OF THE SUBGRADE SOILS AND THE DEPTH OF FOUNDATION STONE WITH CONSIDERATION FOR THE RANGE OF EXPECTED SOIL MOISTURE CONDITIONS. 6. PERIMETER STONE MUST BE EXTENDED HORIZONTALLY TO THE EXCAVATION WALL FOR BOTH VERTICAL AND SLOPED EXCAVATION WALLS. 7. ONCE LAYER 'C' IS PLACED, ANY SOIL/MATERIAL CAN BE PLACED IN LAYER 'D' UP TO THE FINISHED GRADE. MOST PAVEMENT SUBBASE SOILS CAN BE USED TO REPLACE THE MATERIAL REQUIREMENTS OF LAYER 'C' OR 'D' AT THE SITE DESIGN ENGINEER'S DISCRETION. SHEET 1 OF 1 CB#1 - ISOLATOR ROW BYPASS STORMTECH CHAMBERS C2.3 ORMA F ERRA CB #4 - BAYFILTER TRMT. MH T DESIGN GROUP, INC. INFILTRATION GALLERY 'B' - SECTION INFILTRATION GALLERY 'B' - PLAN VIEW C2.4 GAYTEWAY BUSINESS PARK - BUILDING 'B' SITEWORK ORMA F ERRA T DESIGN GROUP, INC. CITY OF ARLINGTON CONSTRUCTION DRAWING REVIEW ACKNOWLEDGMENT THIS PLAN HAS BEEN REVIEWED AND EVALUATED FOR GENERAL COMPLIANCE WITH THE CITY OF ARLINGTON CODES AND ORDINANCES. CONFORMANCE OF THE DESIGN WITH ALL APPLICABLE LAWS AND REGULATIONS IS THE FULL AND COMPLETE RESPONSIBILITY OF THE LICENSED DESIGN ENGINEER WHOSE STAMP AND SIGNATURE APPEAR ON THIS SHEET. ACKNOWLEDGEMENT OF CONSTRUCTION DRAWING REVIEW DOES NOT IMPLY CITY APPROVAL FOR CONSTRUCTION ACTIVITIES THAT REQUIRE OTHER COUNTY, STATE OR FEDERAL PERMIT REVIEW AND APPROVAL. THE PROPERTY OWNER AND LICENSED DESIGN ENGINEER SHALL BE RESPONSIBLE FOR THE ACQUISITION AND COMPLIANCE OF ALL APPLICABLE PERMITS AND/OR AUTHORIZATION WHICH MAY INCLUDE, BUT ARE NOT LIMITED TO, WSDFW HYDRAULIC PROJECT APPROVAL (HPA), WSDOE NOTICE OF INTENT (NOI),ARMY CORP OF ENGINEERS FILL PERMITS AND THE REQUIREMENTS OF THE (NOI),ENDANGERED SPECIES ACT. BY: _______________________________________________ DATE : __________________ Nova Heaton, PE, Development Services Manager THESE APPROVED CONSTRUCITON PLANS EXPIRE AFTER 18 MONTHS FROM THE DATE C1.1 SHOWN ABOVE OR UPON EXPIRATION OF PRELIMINARY PLAN RO SITE PLAN APPROVAL. ORMA F ERRA T DESIGN GROUP, INC. C1.2 ORMA F ERRA T DESIGN GROUP, INC. C1.3 ORMA F ERRA T DESIGN GROUP, INC. C1.4 ORMA F ERRA T DESIGN GROUP, INC. C1.5 ORMA F ERRA T DESIGN GROUP, INC. C1.6 ORMA F ERRA T DESIGN GROUP, INC. C1.7 ORMA F ERRA T DESIGN GROUP, INC. C1.8 CONC. CURB RAMP - PERPENDICULAR CONC. CURB W/ GUTTER HANDICAP STENCIL CONC. CURB RAMP - CENTERED CAST-IN-PLACE CONC. CURB MONOLITHIC CURB & SIDEWALK ORMA F ERRA T DESIGN GROUP, INC. CONCRETE WHEELSTOP ASPHALT PAVING SECTION BOLLARD BIKE RACK - 2 BIKES H.C. PARKING SIGN CONC. SLAB - HEAVY DUTY CONC. WALKWAYS - NO CURB CONC. V-GUTTER PEDESTRIAN TRAIL RAMP C2.1 TEMPORARY SWALE ROCK CONSTRUCTION ENTRANCE FILTER FABRIC FENCE CATCH BASIN FILTER ORMA F ERRA T DESIGN GROUP, INC. TEMP. SEDIMENT / INFILTRATION POND ROCK CHECK DAM C2.2 INFILTRATION GALLERY 'A' - PLAN VIEW COVER PIPE CONNECTION TO END CAP WITH ADS INFILTRATION GALLERY 'A' - SECTION GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE MC-3500 CHAMBER INSTALL UNDER ISOLATOR ROW INSPECTION & MAINTENANCE (NORTH ROW) TWO LAYERS OF ADS STEP 1) INSPECT ISOLATOR ROW FOR SEDIMENT GEOSYNTHETICS 315WTM WOVEN A. INSPECTION PORTS (IF PRESENT) GEOTEXTILE BETWEEN FOUNDATION A.1. REMOVE/OPEN LID ON NYLOPLAST INLINE DRAIN STONE AND CHAMBERS. A.2. REMOVE AND CLEAN FLEXSTORM FILTER IF INSTALLED 8.3-FT MIN. WIDTH STRIPS (MC-3500). A.3. USING A FLASHLIGHT AND STADIA ROD, MEASURE DEPTH OF SEDIMENT AND RECORD ON MAINTENANCE LOG A.4. LOWER A CAMERA INTO ISOLATOR ROW FOR VISUAL INSPECTION OF SEDIMENT LEVELS (OPTIONAL) ORMA A.5. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, F PROCEED TO STEP 3. ACCEPTABLE FILL MATERIALS: STORMTECH MC-3500 CHAMBER SYSTEMS B. ALL ISOLATOR ROWS JLM JLM B.1. REMOVE COVER FROM STRUCTURE AT UPSTREAM END OF ISOLATOR AASHTO MATERIAL COMPACTION / DENSITY ROW MATERIAL LOCATION DESCRIPTION B.2. USING A FLASHLIGHT, INSPECT DOWN THE ISOLATOR ROW THROUGH CLASSIFICATIONS REQUIREMENT OUTLET PIPE FINAL FILL: FILL MATERIAL FOR LAYER 'D' STARTS i) MIRRORS ON POLES OR CAMERAS MAY BE USED TO AVOID A FROM THE TOP OF THE 'C' LAYER TO THE BOTTOM ANY SOIL/ROCK MATERIALS, NATIVE SOILS, OR PER PREPARE PER SITE DESIGN ENGINEER'S PLANS. D OF FLEXIBLE PAVEMENT OR UNPAVED FINISHED ENGINEER'S PLANS. CHECK PLANS FOR PAVEMENT N/A PAVED INSTALLATIONS MAY HAVE STRINGENT CONFINED SPACE ENTRY ERRA GRADE ABOVE. NOTE THAT PAVEMENT SUBBASE SUBGRADE REQUIREMENTS. MATERIAL AND PREPARATION REQUIREMENTS. MC-3500 TY. 2 - 54" CB ii) FOLLOW OSHA REGULATIONS FOR CONFINED SPACE ENTRY IF MAY BE PART OF THE 'D' LAYER ENTERING MANHOLE DESIGN GROUP, INC. AASHTO M145 24" (600 mm) HDPE ACCESS PIPE T BEGIN COMPACTIONS AFTER 24" (600 mm) OF 11/18/14 B.3. IF SEDIMENT IS AT, OR ABOVE, 3" (80 mm) PROCEED TO STEP 2. IF NOT, A-1, A-2-4, A-3 INITIAL FILL: FILL MATERIAL FOR LAYER 'C' GRANULAR WELL-GRADED SOIL/AGGREGATE MIXTURES, <35% MATERIAL OVER THE CHAMBERS IS REACHED. REQUIRED USE FACTORY PROCEED TO STEP 3. STARTS FROM THE TOP OF THE EMBEDMENT FINES OR PROCESSED AGGREGATE. COMPACT ADDITIONAL LAYERS IN 12" (300 mm) PRE-CORED END CAP OR C STONE ('B' LAYER) TO 24" (600 mm) ABOVE THE MAX LIFTS TO A MIN. 95% PROCTOR DENSITY FOR TOP OF THE CHAMBER. NOTE THAT PAVEMENT MOST PAVEMENT SUBBASE MATERIALS CAN BE USED IN LIEU AASHTO M43 WELL GRADED MATERIAL AND 95% RELATIVE STANDARD CROSS SECTION PART #: MC3500IEPP24BC STEP 2) CLEAN OUT ISOLATOR ROW USING THE JETVAC PROCESS SUBBASE MAY BE A PART OF THE 'C' LAYER. OF THIS LAYER. 3, 357, 4, 467, 5, 56, 57, 6, 67, 68, 7, 78, 8, 89, DENSITY FOR PROCESSED AGGREGATE A. A FIXED CULVERT CLEANING NOZZLE WITH REAR FACING SPREAD OF 45" MATERIALS. 9, 10 MC-3500 SECTION (1.1 m) OR MORE IS PREFERRED EMBEDMENT STONE: FILL SURROUNDING THE NTS B. APPLY MULTIPLE PASSES OF JETVAC UNTIL BACKFLUSH WATER IS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43 B CHAMBERS FROM THE FOUNDATION STONE ('A' DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) NO COMPACTION REQUIRED. CLEAN 3, 4 LAYER) TO THE 'C' LAYER ABOVE. ISOLATOR ROW SECTION @ CB #1 C. VACUUM STRUCTURE SUMP AS REQUIRED FOUNDATION STONE: FILL BELOW CHAMBERS CLEAN, CRUSHED, ANGULAR STONE, NOMINAL SIZE AASHTO M43 PLATE COMPACT OR ROLL TO ACHIEVE A FLAT A FROM THE SUBGRADE UP TO THE FOOT (BOTTOM) DISTRIBUTION BETWEEN 3/4-2 INCH (20-50 mm) 3, 4 STEP 3) REPLACE ALL COVERS, GRATES, FILTERS, AND LIDS; RECORD OF THE CHAMBER. OBSERVATIONS AND ACTIONS. PLEASE NOTE: 1. THE LISTED AASHTO DESIGNATIONS ARE FOR GRADATIONS ONLY. THE STONE MUST ALSO BE CLEAN, CRUSHED, ANGULAR. FOR EXAMPLE, A SPECIFICATION FOR #4 STONE WOULD STATE: "CLEAN, CRUSHED, STEP 4) INSPECT AND CLEAN BASINS AND MANHOLES UPSTREAM OF THE ANGULAR NO. 4 (AASHTO M43) STONE". 2. STORMTECH COMPACTION REQUIREMENTS ARE MET FOR 'A' LOCATION MATERIALS WHEN PLACED AND COMPACTED IN 9" (230 mm) (MAX) LIFTS USING TWO FULL COVERAGES WITH A VIBRATORY COMPACTOR. STORMTECH SYSTEM. 3. WHERE INFILTRATION SURFACES MAY BE COMPROMISED BY COMPACTION, FOR STANDARD DESIGN LOAD CONDITIONS, A FLAT SURFACE MAY BE ACHIEVED BY RAKING OR DRAGGING WITHOUT COMPACTION EQUIPMENT. FOR SPECIAL LOAD DESIGNS, CONTACT STORMTECH FOR COMPACTION REQUIREMENTS. NOTES ADS GEOSYNTHETICS 601T NON-WOVEN GEOTEXTILE ALL PAVEMENT LAYER (DESIGNED 1. INSPECT EVERY 6 MONTHS DURING THE FIRST YEAR OF OPERATION. AROUND CLEAN, CRUSHED, ANGULAR STONE IN A & B LAYERS BY SITE DESIGN ENGINEER) ADJUST THE INSPECTION INTERVAL BASED ON PREVIOUS OBSERVATIONS OF SEDIMENT ACCUMULATION AND HIGH WATER D *TO BOTTOM OF FLEXIBLE PAVEMENT. FOR UNPAVED ELEVATIONS. PERIMETER STONE INSTALLATIONS WHERE RUTTING FROM VEHICLES MAY OCCUR, (SEE NOTE 6) C INCREASE COVER TO 30" (750 mm). 2. CONDUCT JETTING AND VACTORING ANNUALLY OR WHEN INSPECTION 12" (300 mm) MIN SHOWS THAT MAINTENANCE IS NECESSARY. B EXCAVATION WALL (CAN BE SLOPED OR VERTICAL) 45" (1140 mm) A DEPTH OF STONE TO BE DETERMINED BY DESIGN ENGINEER 9" (230 mm) MIN 6" (150 mm) MIN MC-3500 9" SUBGRADE SOILS 77" (1950 mm) 12" (300 mm) TYP END CAP (230 mm) MIN (SEE NOTE 5) NOTES: 1. MC-3500 CHAMBERS SHALL CONFORM TO THE REQUIREMENTS OF ASTM F2418 "STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 2. MC-3500 CHAMBERS SHALL BE DESIGNED IN ACCORDANCE WITH ASTM F2787 "STANDARD PRACTICE FOR STRUCTURAL DESIGN OF THERMOPLASTIC CORRUGATED WALL STORMWATER COLLECTION CHAMBERS". 3. "ACCEPTABLE FILL MATERIALS" TABLE ABOVE PROVIDES MATERIAL LOCATIONS, DESCRIPTIONS, GRADATIONS, AND COMPACTION REQUIREMENTS FOR FOUNDATION, EMBEDMENT, AND FILL MATERIALS. 4. THE "SITE DESIGN ENGINEER" REFERS TO THE ENGINEER RESPONSIBLE FOR THE DESIGN AND LAYOUT OF THE STORMTECH CHAMBERS FOR THIS PROJECT. TY. 2 - 54" CB 5. THE SITE DESIGN ENGINEER IS RESPONSIBLE FOR ASSESSING THE BEARING RESISTANCE (ALLOWABLE BEARING CAPACITY) OF THE SUBGRADE SOILS AND THE DEPTH OF FOUNDATION STONE WITH CONSIDERATION FOR THE RANGE OF EXPECTED SOIL MOISTURE CONDITIONS. 6. PERIMETER STONE MUST BE EXTENDED HORIZONTALLY TO THE EXCAVATION WALL FOR BOTH VERTICAL AND SLOPED EXCAVATION WALLS. 7. ONCE LAYER 'C' IS PLACED, ANY SOIL/MATERIAL CAN BE PLACED IN LAYER 'D' UP TO THE FINISHED GRADE. MOST PAVEMENT SUBBASE SOILS CAN BE USED TO REPLACE THE MATERIAL REQUIREMENTS OF LAYER 'C' OR 'D' AT THE SITE DESIGN ENGINEER'S DISCRETION. SHEET 1 OF 1 CB#1 - ISOLATOR ROW BYPASS STORMTECH CHAMBERS C2.3 ORMA F ERRA CB #4 - BAYFILTER TRMT. MH T DESIGN GROUP, INC. BMP T5.13: POST-CONSTRUCTION SOIL QUALITY & DEPTH INFILTRATION GALLERY 'B' - SECTION INFILTRATION GALLERY 'B' - PLAN VIEW C2.4 ORMA F ERRA T DESIGN GROUP, INC. C3.1 ORMA F ERRA T DESIGN GROUP, INC. C3.2 ORMA F ERRA T DESIGN GROUP, INC. C3.3 ORMA F ERRA T DESIGN GROUP, INC. C3.4 ORMA F ERRA T DESIGN GROUP, INC. C3.5 ORMA F ERRA T DESIGN GROUP, INC. C3.6 ORMA F ERRA T DESIGN GROUP, INC. C3.7 ORMA F ERRA T DESIGN GROUP, INC. C3.8 ORMA F ERRA T DESIGN GROUP, INC. ORMA F ERRA T DESIGN GROUP, INC. W 12''SS W W W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W W 12''SS P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) 12''SS P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) P(OH) 12''SS 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W 12''SS W W W 12''SS W 12''SS W W W W SS 12''SS W 12''SS W 12''SS SD W 12''SS W 12''SS W 12''SS NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA LEGEND DATE SECTION - DRIVEWAY AT STA 54+15.32 REVISION 2 C1.2A NO SECTION - CENTER DRIVEWAY ORMA F REMOVABLE BOLLARD NEW STREET NEW STREET NEW STREET ERRA LIGHT ON EX. POLE LIGHT ON EX. POLE LIGHT ON EX. POLE T DESIGN GROUP, INC. NEW DRIVEWAY REMOVE EX. NEW STREET PER DTL. 1/C1.2A TREE (TYP) TREE (TYP) 67TH AVENUE NE (COLLECTOR ARTERIAL) P(OH) PROJECT NO. DRAWN BY: X P(OH) X X X X X CHECKED BY: 370.54' P(OH) P(OH) P(OH) RELOCATE EX. BUILDING 'C' BUILDING 'B' RELOCATE EX. BOLLARDS TO END NEW PEDESTRIAN NEW PEDESTRIAN NEW PEDESTRIAN BOLLARDS TO END BUILDING 'B' OF EACH DRIVEWAY. LIGHT NEW STREET LIGHT REMOVE EX. METER & LIGHT NEW STREET LIGHT REMOVE EX. METER & LIGHT OF EACH DRIVEWAY. PER PLAN BY GATE VALVE. PATCH (TYP) PATCH EX. ASPHALT (TYP) EX. ASPHALT TRAIL TO NEW FIRE HYDRANT NW TRAFFEX (TYP) EX. ASPHALT TRAIL TRAIL (FULL WIDTH) BE SAWCUT & PATCHED PATCH EX. ASPHALT (FULL WIDTH) TRAIL (FULL WIDTH) GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC IN AREAS OF DETERIORATION (AS 2/14/20: 67TH AVENUE REVISIONS SHEET TITLE DETERMINED BY CITY) 67TH AVE - REVISIONS C1.2ASHEET NO. NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA LEGEND DATE REVISION NO ORMA F REMOVABLE BOLLARD NEW STREET NEW STREET NEW STREET ERRA LIGHT ON EX. POLE LIGHT ON EX. POLE NEW DRIVEWAY LIGHT ON EX. POLE T DESIGN GROUP, INC. PER DTL. 3/C1.4 REMOVE EX. NEW STREET (BUILDING 'C' SET) TREE (TYP) TREE (TYP) 67TH AVENUE NE (COLLECTOR ARTERIAL) P(OH) 67TH AVENUE NE PROJECT NO. (COLLECTOR ARTERIAL) DRAWN BY: X P(OH) X X X X X X CHECKED BY: 370.54' P(OH) P(OH) P(OH) RELOCATE EX. BUILDING 'C' BUILDING 'B' RELOCATE EX. BOLLARDS TO END NEW PEDESTRIAN NEW PEDESTRIAN NEW PEDESTRIAN BOLLARDS TO END BUILDING 'B' OF EACH DRIVEWAY. LIGHT NEW STREET LIGHT REMOVE EX. METER & LIGHT NEW STREET LIGHT REMOVE EX. METER & LIGHT OF EACH DRIVEWAY. PER PLAN BY GATE VALVE. PATCH (TYP) PATCH EX. ASPHALT (TYP) EX. ASPHALT TRAIL TO NEW FIRE HYDRANT NW TRAFFEX (TYP) EX. ASPHALT TRAIL TRAIL (FULL WIDTH) BE SAWCUT & PATCHED PATCH EX. ASPHALT (FULL WIDTH) TRAIL (FULL WIDTH) GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC IN AREAS OF DETERIORATION (AS SHEET TITLE DETERMINED BY CITY) 67TH AVE - REVISIONS C1.2ASHEET NO. NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA LEGEND 67TH AVENUE NE (COLLECTOR ARTERIAL) X X X X 370.54' DATE 6 4 4 7 SITE PLAN NOTES 7 8 1 C1.4 REVISION BUILDING 'B' 8 20100 67TH AVENUE NE NO BUILDING 'C' FF = 130.00 AISLE GRADE IS 18" TO 30" BELOW FF ELEV FF = 133.00 7 ORMA F LOT 2 ERRA LOT 1 T DESIGN GROUP, INC. 384.51' 7 443.11' NEW LOT LINE ROADWAY NOTES PROJECT NO. NEW LOT LINE DRAWN BY: 8 CHECKED BY: 3 LOT 3 BMP T5.13: POST CONSTRUCTION SOIL QUALITY & DEPTH ALL DISTURBED AREAS TO REMAIN PERVIOUS SHALL RECEIVE POST 375.71' CONSTRUCTION SOIL AMENDMENT IN ORDER TO IMPROVE RUNOFF BUILDING 'B' RETENTION AND TREATMENT OF POLLUTANTS AND SEDIMENTS FROM DEVELOPMENT. REFER TO DTL. 4/C2.4. GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC NOTE SHEET TITLE CIVIL SITE PLAN SHEET NO. CALL AT LEAST 2 WORKING DAYS BEFORE YOU DIG C1.2 CALL '811' 67TH AVENUE NE NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA (COLLECTOR ARTERIAL) LEGEND C1.4 1 DRWY. PER BLDG 'C' PLANS 370.54' DATE 3 C1.4 REVISION BUILDING 'B' 20100 67TH AVENUE NE BUILDING 'C' FF = 130.00 FF = 133.00 NO BUILDING 'B' LOT 2 ORMA F LOT 1 384.51' ERRA 443.11' T DESIGN GROUP, INC. NEW LOT LINE NEW LOT LINE PROJECT NO. DRAWN BY: CHECKED BY: LOT 3 SECTION - NORTH WALL 375.71' BUILDING 'B' GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC NOTE SHEET TITLE GRADING PLAN SHEET NO. CALL AT LEAST 2 WORKING SECTION - DRIVEWAY CONC. V-GUTTER DAYS BEFORE YOU DIG C1.4 CALL '811' P(OH) NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA 67TH AVENUE NE C1.4 SEE DTL. 3/C1.4 1 (COLLECTOR ARTERIAL) P(OH) P(OH) P(OH) P(OH) SECTION - DRIVEWAY DATE P(OH) P(OH) P(OH) P(OH) 1 C1.2 REVISION P(OH) BUILDING 'C' 19927 67TH AVENUE NE P(OH) FF = 133.00 BUILDING 'B' NO CONC. V-GUTTER P(OH) EP(OH) ORMA P(OH) F E P(OH) ERRA T DESIGN GROUP, INC. P(OH) P(OH) PROJECT NO. P(OH) DRAWN BY: E P(OH) CHECKED BY: P(OH) NORTHERN PACIFIC RAILROAD LEGEND BUILDING 'C' NOTE GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC SHEET TITLE GRADING CITY OF ARLINGTON CONSTRUCTION DRAWING REVIEW APPROVAL PLAN THIS PLAN SHEET HAS BEEN REVIEWED AND APPROVED PER THE CONDITIONS ON THE TITLE SHEET. CALL AT LEAST 2 WORKING 1 DAYS BEFORE YOU DIG C1.4 BY: __________________________________________________________ SHEET NO. Nova Heaton, PE, Development Services Manager CALL '811' SECTION - CENTER DRIVEWAY DATE: _________________ THIS APPROVAL IS VALID FOR 18 MONTHS C1.4 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 1. NEH Easement City needs copy of temporary construction easement with adjacent property prior to construction 2. NEH SWPPP Need physical copy of SWPPP for file 3. NEH Traffic Traffic report body missing, appendix only 4. NEH Plan set Remove as-built signature block 5. NEH Cover Cover signature block needs to be the larger block 6. NEH C1.4 Building submittal and approval required for wall design and engineering prior to civil approval. 7. NEH C1.4 Change wall note on plan â€“ see approved building permit 8. NEH Plan set Plans will be sufficient for a grading permit once area of unsuitable materials excavation, estimated quantity of removal, and design fill material 9. NEH Plan set Signage of vehicle restriction (size) needed at the northern driveway 10. NEH Drainage Report references Snohomish County drainage Report manual instead of SWMMWW 11. NEH Drainage Page 7 & Both say project triggers enhanced treatment Report 10 12. NEH Drainage MR 5 Include T5.13 Report 13. NEH Drainage MR 6 Expand discussion of level of treatment required and Report how met sizing of treatment, number/size of storm filters used, treatment flow rate. 14. NEH Drainage Show infiltration facility drains within required time Report Page 1 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 15. NEH Drainage Discuss if pre-treatment is needed and how (catch in Report CB's, Oil/Water Separators in CB) 16. NEH Drainage Page 10 States enhanced treatment is required, but only basic Report is provided 17. NEH Drainage MR 7 Expand discussion for Flow Control, include required Report size, depth, volume, # of chambers, etc.) 18. LP Grading Construction general permit needed prior to any land disturbing activity 19. GS Water Sheet C1.6 COA Std.4-1.18 Fire Hydrants: W-8 & W-6: As drawn, Hydrant spacing exceeds the 300' Max. 20. GS Water Sheet C1.6 COA Std.4-1.03 Water Mains: 3 At W-6 extend 12" DI North to Lot #3. Use an additional 12" FL Tee and (2) 12" FL x MJ G.V. (North & West) (1) FL x MJ Adapter (South) in place of the (2) 45 bends. 21. GS Water Sheet C1.6 Blow Off Assembly Per COA Std. Detail W-180 22. GS Water Sheet C1.6 W14, W16 & W18 Include "New 2" Water Service Per COA Std. Detail W-050" 23. GS Water Sheet C1.7 The question of coverage on the Storm Crossings. Approximately Sta. # 31+60 (+-) & between Sta. # 35+00 & Sta. # 36+00. COA will allow 6" min. between bottom of 12" DI Water Main and top of Storm with a minimum 30" of Cover over the 12" DI. CDF is required in these areas for support. 24. FR Sewer Sheet C1.3 Temp sediment pond appears to conflict with sewer 25. FR Sewer Sheet C1.3 Note in middle of page referring to existing utilities structures removed/abandoned. All utilities should be Page 2 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved identified so that proper procedures are taken to abandon or remove. 26. FR Sewer Sheet C1.3 Is there a construction sequence to review as to answer the questions above? Page 3 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1.1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 1. NEH Easement City needs copy of temporary construction easement with adjacent property prior to construction 2. NEH SWPPP Need physical copy of SWPPP for file 3. NEH Traffic Traffic report body missing, appendix only 4. NEH Plan set Remove as-built signature block 5. NEH Cover Cover signature block needs to be the larger block 6. NEH C1.4 Building submittal and approval required for wall design and engineering prior to civil approval. 7. NEH C1.4 Change wall note on plan â€“ see approved building permit 8. NEH Plan set Plans will be sufficient for a grading permit once area of unsuitable materials excavation, estimated quantity of removal, and design fill material 9. NEH Plan set Signage of vehicle restriction (size) needed at the northern driveway 10. NEH Drainage Report references Snohomish County drainage Report manual instead of SWMMWW 11. NEH Drainage Page 7 & Both say project triggers enhanced treatment Report 10 12. NEH Drainage MR 5 Include T5.13 Report 13. NEH Drainage MR 6 Expand discussion of level of treatment required and Report how met sizing of treatment, number/size of storm filters used, treatment flow rate. 14. NEH Drainage Show infiltration facility drains within required time Report Page 1 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1.1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 15. NEH Drainage Discuss if pre-treatment is needed and how (catch in Report CB's, Oil/Water Separators in CB) 16. NEH Drainage Page 10 States enhanced treatment is required, but only basic Report is provided 17. NEH Drainage MR 7 Expand discussion for Flow Control, include required Report size, depth, volume, # of chambers, etc.) 18. LP Grading Construction general permit needed prior to any land disturbing activity 19. GS Water Sheet C1.6 COA Std.4-1.18 Fire Hydrants: W-8 & W-6: As drawn, Hydrant spacing exceeds the 300' Max. 20. GS Water Sheet C1.6 COA Std.4-1.03 Water Mains: 3 At W-6 extend 12" DI North to Lot #3. Use an additional 12" FL Tee and (2) 12" FL x MJ G.V. (North & West) (1) FL x MJ Adapter (South) in place of the (2) 45 bends. 21. GS Water Sheet C1.6 Blow Off Assembly Per COA Std. Detail W-180 22. GS Water Sheet C1.6 W14, W16 & W18 Include "New 2" Water Service Per COA Std. Detail W-050" 23. GS Water Sheet C1.7 The question of coverage on the Storm Crossings. Approximately Sta. # 31+60 (+-) & between Sta. # 35+00 & Sta. # 36+00. COA will allow 6" min. between bottom of 12" DI Water Main and top of Storm with a minimum 30" of Cover over the 12" DI. CDF is required in these areas for support. 24. FR Sewer Sheet C1.3 Temp sediment pond appears to conflict with sewer 25. FR Sewer Sheet C1.3 Note in middle of page referring to existing utilities structures removed/abandoned. All utilities should be Page 2 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Gayteway Business Park â€“ Building B Permit No.: PWD#1738 Review Date: 5-28-2019 Contact: Daniel Taylor Phone No.: 206-465-2491 Review Phase: 1.1 Report Date: Reviewing Dept.: CED Applicant: Gayteway Business Park DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved identified so that proper procedures are taken to abandon or remove. 26. FR Sewer Sheet C1.3 Is there a construction sequence to review as to answer the questions above? Page 3 of 3 n Stormwater Pollution Prevention Plan For GAYTEWAY BUSINESS PARK â€“ BUILDING B & C Prepared For City of Arlington Owner Developer Operator/Contractor Gayteway Business Park LLC Gayteway Business Park LLC Not Determined at this Time Contact: Daniel Taylor Contact: Daniel Taylor Ph: (206) 465-2491 Ph: (206) 465-2491 Project Site Location 20015 67th Avenue NE, Arlington, WA 98223 Certified Erosion and Sediment Control Lead Not Determined at this Time SWPPP Prepared By Terraforma Design Group, Inc 5027 51st Avenue SW, Seattle, WA 98136 Pedro DeGuzman, PE, 206-923-0590 SWPPP Preparation Date April 8, 2019 Approximate Project Construction Dates May â€“ December 2019 4/8/2019 i n Contents 1.0 Introduction ..........................................................................................................................â€¦.1 2.0 Site Description ........................................................................................................................3 2.1 Existing Conditions ...........................................................................................................3 2.2 Proposed Construction Activities ......................................................................................5 3.0 Construction Stormwater BMPs ...............................................................................................5 3.1 The 12 BMP Elements .......................................................................................................6 3.1.1 Element #1 â€“ Mark Clearing Limits ................................................................6 3.1.2 Element #2 â€“ Establish Construction Access...................................................6 3.1.3 Element #3 â€“ Control Flow Rates ....................................................................6 3.1.4 Element #4 â€“ Install Sediment Controls ..........................................................6 3.1.5 Element #5 â€“ Stabilize Soils ............................................................................7 3.1.6 Element #6 â€“ Protect Slopes ............................................................................8 3.1.7 Element #7 â€“ Protect Drain Inlets ....................................................................8 3.1.8 Element #8 â€“ Stabilize Channels and Outlets ..................................................8 3.1.9 Element #9 â€“ Control Pollutants ......................................................................8 3.1.10 Element #10 â€“ Control Dewatering .................................................................9 3.1.11 Element #11 â€“ Maintain BMPs ........................................................................9 3.1.12 Element #12 â€“ Manage the Project ..................................................................9 3.2 Site Specific BMPs ..........................................................................................................11 3.3 Additional Advanced BMPs ............................................................................................11 4.0 Construction Phasing and BMP Implementation ...................................................................12 5.0 Pollution Prevention Team ......................................................................................................14 5.1 Roles and Responsibilities ...............................................................................................14 5.2 Team Members ................................................................................................................14 6.0 Site Inspections and Monitoring .............................................................................................15 6.1 Site Inspection .................................................................................................................15 6.1.1 Site Inspection Frequency ..............................................................................15 6.1.2 Site Inspection Documentation ......................................................................16 6.2 Stormwater Quality Monitoring ......................................................................................16 6.2.1 Turbidity ........................................................................................................16 6.2.2 pH ...................................................................................................................17 7.0 Reporting and Recordkeeping ................................................................................................19 7.1 Recordkeeping .................................................................................................................19 7.1.1 Site Log Book ................................................................................................19 7.1.2 Records Retention ..........................................................................................19 7.1.3 Access to Plans and Records..........................................................................19 ii n 7.1.4 Updating the SWPPP .....................................................................................19 7.2 Reporting .........................................................................................................................20 7.2.1 Discharge Monitoring Reports .......................................................................20 7.2.2 Notification of Noncompliance......................................................................20 Appendix A â€“ Site Plans .........................................................................................................21 Appendix B â€“ Construction BMPs .........................................................................................22 Appendix C â€“ Alternative BMPs ............................................................................................22 Appendix D â€“ General Permit ................................................................................................25 Appendix E â€“ Site Inspection Forms (and Site Log) ..............................................................26 Appendix F â€“ Engineering Calculations .................................................................................35 Appendix A Site plans Vicinity map Erosion Control Plan & Details Appendix B Construction BMPs Appendix C Alternative Construction BMP list Appendix D General Permit Appendix E Site Log and Inspection Forms Appendix F Engineering Calculations iii Stormwater Pollution Prevention Plan 1.0 Introduction The proposed development consists of a new office / warehouse / manufacturing building located at 20015 67th Avenue NE. The development comprises 8.5 acres of clearing and grading for Building B & C of the Gayteway Business Park. Site is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. Work includes the proposed site clearing, grading, paving, structures, drainage, utilities, road improvements and landscaping. This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the NPDES stormwater permit requirements for the proposed commercial development. Site disturbance involves an area of approximately 8.5 total acres. A Department of Ecology Stormwater Permit will be applied for since the total clearing and grading area is greater than one acre. The onsite drainage will be retained onsite via infiltration TESC ponds with no offsite discharge. Per discussions with the Ecology and the City, an NPDES permit is still required due to the potential of offsite tracking onto the City streets and downstream storm system. Construction activities will include demolition, excavation, grading, installation of site services/utilities, construction of the building structure, road improvements, paving and landscaping. The purpose of this SWPPP is to describe the proposed construction activities and all temporary and permanent erosion and sediment control (TESC) measures, pollution prevention measures, inspection/monitoring activities, and recordkeeping that will be implemented during the proposed construction project. The objectives of the SWPPP are to: 1. Implement Best Management Practices (BMPs) to prevent erosion and sedimentation, and to identify, reduce, eliminate or prevent stormwater contamination and water pollution from construction activity. 2. Prevent violations of surface water quality, ground water quality, or sediment management standards. 3. Prevent, during the construction phase, adverse water quality impacts including impacts on beneficial uses of the receiving water by controlling peak flow rates and volumes of stormwater runoff at the Permitteeâ€™s outfalls and downstream of the outfalls. This SWPPP was prepared using the Ecology SWPPP Template downloaded from the Ecology website. This SWPPP was prepared based on the requirements set forth in the Construction Stormwater General Permit, Stormwater Management Manual for Western Washington (SWMMWW 2014). The report is divided into seven main sections with several appendices that include stormwater related reference materials. The topics presented in the each of the main sections are: 1 Stormwater Pollution Prevention Plan Section 1 â€“ INTRODUCTION. This section provides a summary description of the project, and the organization of the SWPPP document. Section 2 â€“ SITE DESCRIPTION. This section provides a detailed description of the existing site conditions, proposed construction activities, and calculated stormwater flow rates for existing conditions and postâ€“ construction conditions. Section 3 â€“ CONSTRUCTION BMPs. This section provides a detailed description of the BMPs to be implemented based on the 12 required elements of the SWPPP (SWMMEW 2004). Section 4 â€“ CONSTRUCTION PHASING AND BMP IMPLEMENTATION. This section provides a description of the timing of the BMP implementation in relation to the project schedule. Section 5 â€“ POLLUTION PREVENTION TEAM. This section identifies the appropriate contact names (emergency and non-emergency), monitoring personnel, and the onsite temporary erosion and sedimentation control inspector Section 6 â€“ INSPECTION AND MONITORING. This section provides a description of the inspection and monitoring requirements such as the parameters of concern to be monitored, sample locations, sample frequencies, and sampling methods for all stormwater discharge locations from the site. Section 7 â€“ RECORDKEEPING. This section describes the requirements for documentation of the BMP implementation, site inspections, monitoring results, and changes to the implementation of certain BMPs due to site factors experienced during construction. Supporting documentation and standard forms are provided in the following Appendices: Appendix A â€“ Site plans Appendix B â€“ Construction BMPs Appendix C â€“ Alternative Construction BMP list Appendix D â€“ General Permit Appendix E â€“ Site Log and Inspection Forms Appendix F â€“ Engineering Calculations Appendix G â€“ Clear Creek Systems Stormwater Chemical Treatment Plan 2 Stormwater Pollution Prevention Plan 2.0 Site Description 2.1 Existing Conditions The site comprises 7.8 acres on site development. The property is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. The existing property was previously used for lumber operations and has since been vacated and structures cleared. The site is predomimately exposed soil. The property slopes slightly to the north at an average gradient of 1.5 percent. The site receives minimal drainage from adjacent properties. There are some onsite catch basins and storm drains; runoff partially discharges to the existing City storm system in 67th Avenue NE. There is an infiltration pond at the northeast corner of the property. At this time it is unclear as to the total area that this pond serves. The pond may be removed with the future Building B development. The property is not within the 100-yr floodplain. We do not know of any onsite or nearby wetlands or sensitive areas. Portage Creek is approximately one-half mile downstream to the northwest. The existing soils are classified as Everett Very Gravelly Sany Loam, 0- to 8 percent slopes according to the National Cooperative Soil Survey by the USDA Natural Resources Conservation Service. These soils are generally consist of very gravelly sandy loam. Depth to densic material is is greater than 80 inches depth. The soils belong to Hydraulic Soil Group â€˜Aâ€™. A Soil Infiltration Rate study was prepared by Sondergaard Geoscience, PLLC, dated April 24, 2018. Twelve exploration pits we done over the 8.3 acre portion west of the railroad tracks. Existing soils generally consisted of crushed rock fill over some pockets of wood fill over Recessional Outwash. The outwash material was encountered to depths of 9 to 14 feet below grade and consisted of medium dense, moist, oxidized brown to gray, gravelly sand to sandy gravel and scattered cobbles. Groundwater seepage was not encountered with the exception of pit EP-9 (at 6.5-ft depth near the NE corner of the 8.3 acre property). Infiltration rates were measured using grain size analyses at six (6) planned infiltration locations. Rates varied from 38 to 568 in/hr with test depths of 7 to 9 feet. A design infiltration rate of 13.7 in/hr was recommended by the geotechnical engineer (report provided separately to the City. A site vicinity map is provided in Appendix A. 3 Stormwater Pollution Prevention Plan EXISTING SITE AERIAL & SOIL IDENTIFIER 4 Stormwater Pollution Prevention Plan 2.2 Proposed Construction Activities The proposed development consists of 2 new office / warehouse / manufacturing building located at 20015 67th Avenue NE. The development comprises 7.8 acres of onsite disturbance and an additional 0.7 acres of work within 67th Avenue NE. The property is part of a 54 acre parcel which encompasses the west and east side of the Northern Pacific Railroad. Work includes the proposed site clearing, grading, paving, structures, drainage, utilities, road improvements and landscaping. The project will require drainage review from the City of Arlington and compliance with the 2014 Washington State Department of Ecology Surface Water Management Manual for Western Washington. A Department of Ecology Construction Stormwater Permit will be required since the site disturbance exceeds one acre and there is a potential for offsite discharge of runoff due to work in the right-of-way that will not discharge to the onsite infiltration TESC pond. Onsite drainage improvements includes new catch basins and storm drainage for surface runoff. Stormwater infiltration will be proposed for the proposed parking, landscaping and roof drainage runoff; underground infiltration chambers are proposed at this time. A sediment pond will be constructed within the work area. The pond is designed as an infiltration pond with a design infiltration rate of 10.0 in/hr. The 2-year and 10-year storm event will be analyzed to confirm the pond has the capacity to serve the onsite 7.8 acre site disturbance. After the building is constructed and all new utilities are installed, the site will be stabilized with hard surface, landscaping and erosion control grasses. The following summarizes details regarding site areas: Total onsite work area: 7.8 acres Off-site work area (in 67th Ave NE) 0.7 acres Total Work Area: 8.5 acres 5 Stormwater Pollution Prevention Plan 3.0 Construction Stormwater BMPs 3.1 The 12 BMP Elements 3.1.1 Element #1 â€“ Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction will be clearly marked before land-disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the field and on the plans. In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the maximum extent possible. The BMPs relevant to marking the clearing limits that will be applied for this project include: BMP C233: Silt Fence. Silt fence is proposed along the site perimeter whether the adjacent gradient is lower than the site. 3.1.2 Element #2 â€“ Establish Construction Access Construction access or activities occurring on unpaved areas shall be minimized, yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads, and wheel washing, street sweeping, and street cleaning shall be employed to prevent sediment from entering state waters. All wash wastewater shall be controlled on site. The specific BMPs related to establishing construction access that will be used on this project include: BMP C105: Stabilized Construction Entrance BMP C107: Construction Road / Parking Area Stabilization 3.1.3 Element #3 â€“ Control Flow Rates In order to protect the properties and waterways downstream of the project site, stormwater discharges from the site will be controlled. The specific BMPs for flow control that shall be used on this project include: Runoff will be retained within an onsite infiltration TESC pond. 3.1.4 Element #4 â€“ Install Sediment Controls All stormwater runoff from disturbed areas shall pass through an appropriate sediment removal BMP before leaving the construction site. The specific BMPs to be used for controlling sediment on this project include: 6 Stormwater Pollution Prevention Plan BMP C207: Check Dams. Check dams are proposed along the proposed interceptor swales. BMP C233: Silt Fence BMP C241: Temporary Sediment Pond (infiltration) Alternate sediment control BMPs are included in Appendix C as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy City of Arlington standards. The Certified Erosion and Sediment Control Lead shall promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. In addition, sediment will be removed from paved areas in and adjacent to construction work areas manually or using mechanical sweepers, as needed, to minimize tracking of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. Sediment laden runoff shall not be discharged to the Filterra vaults; all site areas shall be stabilized prior to runoff discharge to these facilities. Failure to comply with this guideline may require replacement by the contractor at no additional cost to the owner. 3.1.5 Element #5 â€“ Stabilize Soils Exposed and unworked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. The specific BMPs for soil stabilization that shall be used on this project include: BMP C120: Temporary and Permanent Seeding BMP C121: Mulching BMP C125: Topsoiling BMP C140: Dust Control In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. 7 Stormwater Pollution Prevention Plan 3.1.6 Element #6 â€“ Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner that minimizes erosion. The following specific BMPs will be used to protect slopes for this project: BMP C122: Nets and Blankets BMP C123: Plastic Covering 3.1.7 Element #7 â€“ Protect Drain Inlets All storm drain inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. Storm Drain Inlet Protection (BMP C220) will be implemented for all drainage inlets and culverts that could potentially be impacted by sediment-laden runoff on and near the project site. The following inlet protection measures will be applied on this project: BMP C220: Storm Drain Inlet Protection 3.1.8 Element #8 â€“ Stabilize Channels and Outlets Where site runoff is to be conveyed in channels, or discharged to a stream or some other natural drainage point, efforts will be taken to prevent downstream erosion. The specific BMPs for channel and outlet stabilization that shall be used on this project include: BMP C209: Outlet Protection. Riprap pad is proposed at the outlet of the interceptor swale to the sediment pond. Alternate channel and outlet stabilization BMPs are included in Appendix C as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. 3.1.9 Element #9 â€“ Control Pollutants All pollutants, including waste materials and demolition debris, that occur onsite shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good 8 Stormwater Pollution Prevention Plan housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. The specific BMPs for pollutant control include: BMP C151: Concrete Handling BMP C152: Sawcutting and Surfacing Pollution Prevention BMP C153: Material Delivery, Storage and Containment BMP C250: Construction Stormwater Chemical Treatment BMP C251: Construction Stormwater Filtration The facility is not transportation-related and therefore subject to the criteria for determining if a Spill Prevention, Control, and Countermeasure (SPCC) Plan is required under the Federal regulations of the Clean Water Act (CWA). A Source Control Plan is provided within this report to address these regulations 3.1.10 Element #10 â€“ Control Dewatering Dewatering may be necessary depending on the time of construction and fluctuating groundwater conditions. Contractor shall be prepared to address dewatering conditions and ensure that sediment laden run-off is not discharged to adjacent properties or the off-site stormwater system. Contact the Engineer is Dewatering will be necessary based on field conditions. The specific BMPs for project management include: BMP C160: Certified Erosion and Sediment Control Lead BMP C162: Scheduling 3.1.11 Element #11 - Maintain BMPs 1. All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. 2. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Appendix B of this report). 3. Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. 9 Stormwater Pollution Prevention Plan 4. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. 5. Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. 6. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be returned to conditions specified in the construction documents. 3.1.12 Element #12 - Manage the Project The project will be managed based on the following principles: â€¢ Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account. â€¢ Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Section 6 of this report â€¢ Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Section 6 & 7 of this Report. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Management Emphasize erosion control rather than sediment control Minimize the extent and duration of the area exposed Keep runoff velocities low Retain sediment on-site Thoroughly monitor site and maintain all ESC measures Other (please describe) 10 Stormwater Pollution Prevention Plan 3.2 Site Specific BMPs Site specific BMPs are shown on the TESC Plan Sheets and Details in Appendix A and B. 3.3 Additional Advanced BMPs Additional Advanced BMPs are provided within Appendix C. 11 Stormwater Pollution Prevention Plan 4.0 Construction Phasing and BMP Implementation The BMP implementation schedule is driven by the construction schedule. The following provides a sequential list of the proposed construction schedule milestones and the corresponding BMP implementation schedule. The list contains key milestones such as wet season construction. BMP implementation schedule listed below is keyed to proposed phases of the construction project, and reflects differences in BMP installations and inspections that relate to wet season construction. The project site is located west of the Cascade Mountain Crest. As such, the dry season is considered to be from May 1 to September 30 and the wet season is considered to be from October 1 to April 30. The contractor shall revise the following construction schedule based on his start date and construction methods / timing. Dry Season starts: 5/1/2019 Estimate of Construction start date: 5/10/2019 Mobilize equipment on site: 5/10/2019 Mobilize and store all ESC and soil stabilization products (store materials on hand BMP C150): 5/10/2019 Install ESC measures & construction entrance: 5/12/2019 Install Sediment Pond 5/13/2019 Begin clearing and grubbing: 5/14/2019 Begin implementing soil stabilization and sediment control BMPs throughout the site: 5/14/2019 Site inspections and monitoring conducted weekly and for applicable rain events as detailed in Section 6 of this SWPPP: 5/15/2019 Implement Element #12 BMPs and manage site to minimize soil disturbance during the wet season 5/15/2019 Begin site grading and unsuitable soil overex: 5/16/2019 Excavation & construction of building foundations 5/31/2019 12 Stormwater Pollution Prevention Plan Begin building and utility construction: 6/25/2019 Wet Season starts: 10/1/ 2019 Building construction complete: 11/27/2019 Final landscaping and planting begins: 12/2/2019 Permanent erosion control measures (hydroseeding): 12/10//2019 Remove erosion control fencing, cb protections: 12/13/2019 Estimate of Construction finish date: 12/15/2019 13 Stormwater Pollution Prevention Plan 5.0 Pollution Prevention Team 5.1 Roles and Responsibilities The pollution prevention team consists of personnel responsible for implementation of the SWPPP, including the following: Certified Erosion and Sediment Control Lead (CESCL) â€“ primary contractor contact, responsible for site inspections (BMPs, visual monitoring, sampling, etc.); to be called upon in case of failure of any ESC measures. Resident Engineer â€“ For projects with engineered structures only (sediment ponds/traps, sand filters, etc.): site representative for the owner that is the project's engineer responsible for issuing instructions and drawings to the contractor's site supervisor or representative Emergency Contact â€“ designated City of Arlington sitework inspector. Note: A Department of Ecology Stormwater Permit will be applied for with this project. Non-Emergency Ecology Contact â€“ individual that is the site owner or representative of the site owner than can be contacted if required. Monitoring Personnel â€“ personnel responsible for conducting water quality monitoring; for most sites this person is also the Certified Erosion and Sediment Control Lead. 5.2 Team Members Names and contact information for those identified as members of the pollution prevention team are provided in the following table. Note: since that contractor has not been determined at this time, contractor shall complete the blank fields. Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) By contractor; not determined at this time Resident Engineer Terraforma: Pedro DeGuzman, PE 206-923-0590 Emergency City of Arlington Contact City Inspector: Emergency Owner Contact Gayteway Business Park, attn: Dan Taylor 206-465-2491 Non-Emergency City of Arlington Contact Monitoring Personnel By contractor; not determined at this time 14 Stormwater Pollution Prevention Plan 6.0 Site Inspections and Monitoring Monitoring includes visual inspection, monitoring for water quality parameters of concern, and documentation of the inspection and monitoring findings in a site log book. A site log book will be maintained for all on-site construction activities and will include: A record of the implementation of the SWPPP and other permit requirements; Site inspections; and, Stormwater quality monitoring. For convenience, the inspection form and water quality monitoring forms included in this SWPPP include the required information for the site log book. This SWPPP may function as the site log book if desired, or the forms may be separated and included in a separate site log book. However, if separated, the site log book but must be maintained on-site or within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. 6.1 Site Inspection All BMPs will be inspected, maintained, and repaired as needed to assure continued performance of their intended function. The inspector will be a Certified Erosion and Sediment Control Lead (CESCL) per BMP C160. The name and contact information for the CESCL is provided in Section 5 of this SWPPP. Site inspection will occur in all areas disturbed by construction activities and at all stormwater discharge points. Stormwater will be examined for the presence of suspended sediment, turbidity, discoloration, and oily sheen. The site inspector will evaluate and document the effectiveness of the installed BMPs and determine if it is necessary to repair or replace any of the BMPs to improve the quality of stormwater discharges. All maintenance and repairs will be documented in the site log book or forms provided in this document. All new BMPs or design changes will be documented in the SWPPP as soon as possible. 6.1.1 Site Inspection Frequency Site inspections will be conducted at least once a week and within 24 hours following any rainfall event which causes a discharge of stormwater from the site. For sites with temporary stabilization measures, the site inspection frequency can be reduced to once every month. 15 Stormwater Pollution Prevention Plan 6.1.2 Site Inspection Documentation The site inspector will record each site inspection using the site log inspection forms provided in Appendix E. The site inspection log forms may be separated from this SWPPP document, but will be maintained on-site or within reasonable access to the site and be made available upon request to The City or the local jurisdiction. 6.2 Stormwater Quality Monitoring 6.2.1 Turbidity Onsite runoff will be retained onsite via the infiltration TESC Pond. Turbidity monitoring will be required for the downstream 67th Avenue NE catch basins to verify no increase in runoff turbidity as a result on dirt tracking into the right-of-way. Turbidity sampling and monitoring will be conducted during the entire construction phase of the project. Samples will be collected daily at the catch basin in the northwest corner of the site (CB5). If there is no flow in this catch basin, the attempt to sample will be recorded in the site log book and reported to Ecology in the monthly Discharge Monitoring Report (DMR) as â€œNo Dischargeâ€. Samples will be analyzed for turbidity using the EPA 180.1 analytical method. The key benchmark turbidity value is 25 nephelometric turbidity units (NTU) for the downstream receiving water body. If the 25 NTU benchmark is exceeded in any sample collected from CB5, the following steps will be conducted: 1. Ensure all BMPs specified in this SWPPP are installed and functioning as intended. 2. Assess whether additional BMPs should be implemented, and document modified BMPs in the SWPPP as necessary. 3. Sample discharge daily until the discharge is 25 NTU or lower. If the turbidity exceeds 250 NTU at any time, the following steps will be conducted: 1. Notify Ecology by phone within 24 hours of analysis (see Section 5.0 of this SWPPP for contact information). 2. Continue sampling daily until the discharge is 25 NTU or lower Initiate additional treatment BMPs such as off-site treatment, infiltration, filtration and chemical treatment within 24 hours, and implement those additional treatment BMPs as soon as possible, but within a minimum of 7 days. 16 Stormwater Pollution Prevention Plan 3. Describe inspection results and remedial actions taken in the site log book and in monthly discharge monitoring reports as described in Section 7.0 of this SWPPP. 6.2.2 pH Sampling and monitoring for pH will occur during the phase of construction when concrete pouring will be conducted until fully cured (3 weeks from last pour) and discharges are documented to be below pH 8.5. Samples will be collected weekly at the sedimentation pond prior to discharge to surface water. Samples will be analyzed for pH using a calibrated pH meter and recorded in the site log book. The key benchmark pH value for stormwater is a maximum of 8.5. If a pH greater than 8.5 is measured in the sedimentation trap/pond(s) that has the potential to discharge to surface water, the following steps will be conducted: 1. Prevent (detain) all discharges from leaving the site and entering surface waters or storm drains if the pH is greater than 8.5 2. Implement CO2 sparging or dry ice treatment in accordance with Ecology BMP C252. 3. Describe inspection results and remedial actions that are taken in the site log book and in monthly discharge monitoring reports as described in Section 7.0 of this SWPPP. 17 Stormwater Pollution Prevention Plan 7.0 Reporting and Recordkeeping 7.1 Recordkeeping 7.1.1 Site Log Book A site log book will be maintained for all on-site construction activities and will include: A record of the implementation of the SWPPP and other permit requirements; Site inspections; and, Stormwater quality monitoring. For convenience, the inspection form and water quality monitoring forms included in this SWPPP include the required information for the site log book. 7.1.2 Records Retention Records of all monitoring information (site log book, inspection reports/checklists, etc.), this Stormwater Pollution Prevention Plan, and any other documentation of compliance with permit requirements will be retained during the life of the construction project and for a minimum of three years following the termination of permit coverage in accordance with permit condition S5.C. 7.1.3 Access to Plans and Records The SWPPP and Site Log Book will be retained on site or within reasonable access to the site and will be made immediately available upon request to the City of Arlington. A copy of this SWPPP will be provided to the City of Arlington within 14 days of receipt of a written request for the SWPPP. Any other information requested by the City will be submitted within a reasonable time. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing. 7.1.4 Updating the SWPPP This SWPPP will be modified if the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site or there has been a change in 19 Stormwater Pollution Prevention Plan design, construction, operation, or maintenance at the site that has a significant effect on the discharge, or potential for discharge, of pollutants to the waters of the State. The SWPPP will be modified within seven days of determination based on inspection(s) that additional or modified BMPs are necessary to correct problems identified, and an updated timeline for BMP implementation will be prepared. 7.2 Reporting 7.2.1 Discharge Monitoring Reports Discharge Monitoring Report (DMR) forms will not be submitted to the City unless requested by the City Inspector. 7.2.2 Department of Ecology Reporting All reporting requirements of the Department of Ecology Stormwater Permit shall be adhered to by the contractor. The contractor shall have a copy of the DOE permit at the jobsite. 7.2.3 Notification of Noncompliance If any of the terms and conditions of the permit are not met, and it causes a threat to human health or the environment, the following steps will be taken: 1. The City of Arlington will be immediately notified of the failure to comply. 2. Immediate action will be taken to control the noncompliance issue and to correct the problem. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to the City within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to the City within five (5) days, unless requested earlier by the City. 20 Stormwater Pollution Prevention Plan Appendix A â€“ Site Plans VICINITY MAP C1.3 TESC & EARTHWORK OVEREX C2.2 EROSION CONTROL DETAILS & NOTES 21 ORMA F ERRA T DESIGN GROUP, INC. CITY OF ARLINGTON CONSTRUCTION DRAWING REVIEW APPROVAL THIS PLAN SHEET HAS BEEN REVIEWED AND APPROVED PER THE CONDITIONS ON THE TITLE SHEET. BY: __________________________________________________________ Nova Heaton, PE, Development Services Manager DATE: _________________ THIS APPROVAL IS VALID FOR 18 MONTHS C1.3 TEMPORARY SWALE ROCK CONSTRUCTION ENTRANCE FILTER FABRIC FENCE CATCH BASIN FILTER ORMA F ERRA T DESIGN GROUP, INC. TEMP. SEDIMENT / INFILTRATION POND ROCK CHECK DAM CITY OF ARLINGTON CONSTRUCTION DRAWING REVIEW APPROVAL THIS PLAN SHEET HAS BEEN REVIEWED AND APPROVED PER THE CONDITIONS ON THE TITLE SHEET. BY: __________________________________________________________ Nova Heaton, PE, Development Services Manager DATE: _________________ THIS APPROVAL IS VALID FOR 18 MONTHS C2.2 Stormwater Pollution Prevention Plan Appendix B â€“ Construction BMPs BMP C103: High Visibility Plastic or Metal Fence BMP C105: Stabilized Construction Entrance BMP C107: Construction Road/Parking Area Stabilization BMP C120: Temporary and Permanent Seeding BMP C121: Mulching BMP C122: Nets and Blankets BMP C123: Plastic Covering BMP C125: Topsoiling BMP C140: Dust Control BMP C150: Materials On Hand BMP C151: Concrete Handling BMP C152: Sawcutting and Surfacing Pollution Prevention BMP C153: Material Delivery, Storage and Containment BMP C160: Certified Erosion and Sediment Control Lead BMP C200: Interceptor Dike and Swale BMP C207: Check Dams BMP C209: Outlet Protection BMP C220: Storm Drain Inlet Protection BMP C233: Silt Fence BMP C241: Temporary Sediment Pond BMP C250: Construction Stormwater Chemical Treatment BMP C251: Construction Stormwater Filtration 22 BMP C101: Preserving Natural Vegetation Purpose The purpose of preserving natural vegetation is to reduce erosion wherever practicable. Limiting site disturbance is the single most effective method for reducing erosion. For example, conifers can hold up to about 50 percent of all rain that falls during a storm. Up to 20-30 percent of this rain may never reach the ground but is taken up by the tree or evaporates. Another benefit is that the rain held in the tree can be released slowly to the ground after the storm. Conditions of Use Natural vegetation should be preserved on steep slopes, near perennial and intermittent watercourses or swales, and on building sites in wooded areas. â€¢ As required by local governments. â€¢ Phase construction to preserve natural vegetation on the project site for as long as possible during the construction period. Design and Natural vegetation can be preserved in natural clumps or as individual Installation trees, shrubs and vines. Specifications The preservation of individual plants is more difficult because heavy equipment is generally used to remove unwanted vegetation. The points to remember when attempting to save individual plants are: â€¢ Is the plant worth saving? Consider the location, species, size, age, vigor, and the work involved. Local governments may also have ordinances to save natural vegetation and trees. â€¢ Fence or clearly mark areas around trees that are to be saved. It is preferable to keep ground disturbance away from the trees at least as far out as the dripline. Plants need protection from three kinds of injuries: â€¢ Construction Equipment - This injury can be above or below the ground level. Damage results from scarring, cutting of roots, and compaction of the soil. Placing a fenced buffer zone around plants to be saved prior to construction can prevent construction equipment injuries. â€¢ Grade Changes - Changing the natural ground level will alter grades, which affects the plant's ability to obtain the necessary air, water, and minerals. Minor fills usually do not cause problems although sensitivity between species does vary and should be checked. Trees can typically tolerate fill of 6 inches or less. For shrubs and other plants, the fill should be less. When there are major changes in grade, it may become necessary to supply air to the roots of plants. This can be done by placing a layer of gravel and a tile system over the roots before the fill is made. A tile system protects a tree from a raised grade. The tile system should be Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-3 laid out on the original grade leading from a dry well around the tree trunk. The system should then be covered with small stones to allow air to circulate over the root area. Lowering the natural ground level can seriously damage trees and shrubs. The highest percentage of the plant roots are in the upper 12 inches of the soil and cuts of only 2-3 inches can cause serious injury. To protect the roots it may be necessary to terrace the immediate area around the plants to be saved. If roots are exposed, construction of retaining walls may be needed to keep the soil in place. Plants can also be preserved by leaving them on an undisturbed, gently sloping mound. To increase the chances for survival, it is best to limit grade changes and other soil disturbances to areas outside the dripline of the plant. â€¢ Excavations - Protect trees and other plants when excavating for drainfields, power, water, and sewer lines. Where possible, the trenches should be routed around trees and large shrubs. When this is not possible, it is best to tunnel under them. This can be done with hand tools or with power augers. If it is not possible to route the trench around plants to be saved, then the following should be observed: Cut as few roots as possible. When you have to cut, cut clean. Paint cut root ends with a wood dressing like asphalt base paint if roots will be exposed for more than 24-hours. Backfill the trench as soon as possible. Tunnel beneath root systems as close to the center of the main trunk to preserve most of the important feeder roots. Some problems that can be encountered with a few specific trees are: â€¢ Maple, Dogwood, Red alder, Western hemlock, Western red cedar, and Douglas fir do not readily adjust to changes in environment and special care should be taken to protect these trees. â€¢ The windthrow hazard of Pacific silver fir and madrona is high, while that of Western hemlock is moderate. The danger of windthrow increases where dense stands have been thinned. Other species (unless they are on shallow, wet soils less than 20 inches deep) have a low windthrow hazard. â€¢ Cottonwoods, maples, and willows have water-seeking roots. These can cause trouble in sewer lines and infiltration fields. On the other hand, they thrive in high moisture conditions that other trees would not. â€¢ Thinning operations in pure or mixed stands of Grand fir, Pacific silver fir, Noble fir, Sitka spruce, Western red cedar, Western hemlock, Pacific dogwood, and Red alder can cause serious disease problems. Disease can become established through damaged limbs, trunks, roots, Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-4 and freshly cut stumps. Diseased and weakened trees are also susceptible to insect attack. Maintenance Inspect flagged and/or fenced areas regularly to make sure flagging or Standards fencing has not been removed or damaged. If the flagging or fencing has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. â€¢ If tree roots have been exposed or injured, â€œpruneâ€ cleanly with an appropriate pruning saw or lopers directly above the damaged roots and recover with native soils. Treatment of sap flowing trees (fir, hemlock, pine, soft maples) is not advised as sap forms a natural healing barrier. BMP C102: Buffer Zones Purpose Creation of an undisturbed area or strip of natural vegetation or an established suitable planting that will provide a living filter to reduce soil erosion and runoff velocities. Conditions of Use Natural buffer zones are used along streams, wetlands and other bodies of water that need protection from erosion and sedimentation. Vegetative buffer zones can be used to protect natural swales and can be incorporated into the natural landscaping of an area. Critical-areas buffer zones should not be used as sediment treatment areas. These areas shall remain completely undisturbed. The local permitting authority may expand the buffer widths temporarily to allow the use of the expanded area for removal of sediment. Design and â€¢ Preserving natural vegetation or plantings in clumps, blocks, or strips Installation is generally the easiest and most successful method. Specifications â€¢ Leave all unstable steep slopes in natural vegetation. â€¢ Mark clearing limits and keep all equipment and construction debris out of the natural areas and buffer zones. Steel construction fencing is the most effective method in protecting sensitive areas and buffers. Alternatively, wire-backed silt fence on steel posts is marginally effective. Flagging alone is typically not effective. â€¢ Keep all excavations outside the dripline of trees and shrubs. â€¢ Do not push debris or extra soil into the buffer zone area because it will cause damage from burying and smothering. â€¢ Vegetative buffer zones for streams, lakes or other waterways shall be established by the local permitting authority or other state or federal permits or approvals. Maintenance Inspect the area frequently to make sure flagging remains in place and the Standards area remains undisturbed. Replace all damaged flagging immediately. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-5 BMP C103: High Visibility Fence Purpose Fencing is intended to: 1. Restrict clearing to approved limits. 2. Prevent disturbance of sensitive areas, their buffers, and other areas required to be left undisturbed. 3. Limit construction traffic to designated construction entrances, exits, or internal roads. 4. Protect areas where marking with survey tape may not provide adequate protection. Conditions of Use To establish clearing limits plastic, fabric, or metal fence may be used: â€¢ At the boundary of sensitive areas, their buffers, and other areas required to be left uncleared. â€¢ As necessary to control vehicle access to and on the site. Design and High visibility plastic fence shall be composed of a high-density Installation polyethylene material and shall be at least four feet in height. Posts for Specifications the fencing shall be steel or wood and placed every 6 feet on center (maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as a top stringer to prevent sagging between posts. The fence color shall be high visibility orange. The fence tensile strength shall be 360 lbs./ft. using the ASTM D4595 testing method. If appropriate install fabric silt fence in accordance with BMP C233 to act as high visibility fence. Silt fence shall be at least 3 feet high and must be highly visible to meet the requirements of this BMP. Metal fences shall be designed and installed according to the manufacturer's specifications. Metal fences shall be at least 3 feet high and must be highly visible. Fences shall not be wired or stapled to trees. Maintenance If the fence has been damaged or visibility reduced, it shall be repaired or Standards replaced immediately and visibility restored. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-6 BMP C105: Stabilized Construction Entrance / Exit Purpose Stabilized Construction entrances are established to reduce the amount of sediment transported onto paved roads by vehicles or equipment. This is done by constructing a stabilized pad of quarry spalls at entrances and exits for construction sites. Conditions of Use Construction entrances shall be stabilized wherever traffic will be entering or leaving a construction site if paved roads or other paved areas are within 1,000 feet of the site. For residential construction provide stabilized construction entrances for each residence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient length/width to provide vehicle access/parking, based on lot size/configuration. On large commercial, highway, and road projects, the designer should include enough extra materials in the contract to allow for additional stabilized entrances not shown in the initial Construction SWPPP. It is difficult to determine exactly where access to these projects will take place; additional materials will enable the contractor to install them where needed. Design and See Figure 4.1.1 for details. Note: the 100â€™ minimum length of the Installation entrance shall be reduced to the maximum practicable size when the size Specifications or configuration of the site does not allow the full length (100â€™). Construct stabilized construction entrances with a 12-inch thick pad of 4- inch to 8-inch quarry spalls, a 4-inch course of asphalt treated base (ATB), or use existing pavement. Do not use crushed concrete, cement, or calcium chloride for construction entrance stabilization because these products raise pH levels in stormwater and concrete discharge to surface waters of the State is prohibited. A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the following standards: Grab Tensile Strength (ASTM D4751) 200 psi min. Grab Tensile Elongation (ASTM 30% max. D4632) Mullen Burst Strength (ASTM 400 psi min. D3786-80a) AOS (ASTM D4751) 20-45 (U.S. standard sieve size) â€¢ Consider early installation of the first lift of asphalt in areas that will paved; this can be used as a stabilized entrance. Also consider the installation of excess concrete as a stabilized entrance. During large concrete pours, excess concrete is often available for this purpose. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-7 â€¢ Fencing (see BMP C103) shall be installed as necessary to restrict traffic to the construction entrance. â€¢ Whenever possible, the entrance shall be constructed on a firm, compacted subgrade. This can substantially increase the effectiveness of the pad and reduce the need for maintenance. â€¢ Construction entrances should avoid crossing existing sidewalks and back of walk drains if at all possible. If a construction entrance must cross a sidewalk or back of walk drain, the full length of the sidewalk and back of walk drain must be covered and protected from sediment leaving the site. Maintenance Quarry spalls shall be added if the pad is no longer in accordance with Standards the specifications. â€¢ If the entrance is not preventing sediment from being tracked onto pavement, then alternative measures to keep the streets free of sediment shall be used. This may include replacement/cleaning of the existing quarry spalls, street sweeping, an increase in the dimensions of the entrance, or the installation of a wheel wash. â€¢ Any sediment that is tracked onto pavement shall be removed by shoveling or street sweeping. The sediment collected by sweeping shall be removed or stabilized on site. The pavement shall not be cleaned by washing down the street, except when high efficiency sweeping is ineffective and there is a threat to public safety. If it is necessary to wash the streets, the construction of a small sump to contain the wash water shall be considered. The sediment would then be washed into the sump where it can be controlled. â€¢ Perform street sweeping by hand or with a high efficiency sweeper. Do not use a non-high efficiency mechanical sweeper because this creates dust and throws soils into storm systems or conveyance ditches. â€¢ Any quarry spalls that are loosened from the pad, which end up on the roadway shall be removed immediately. â€¢ If vehicles are entering or exiting the site at points other than the construction entrance(s), fencing (see BMP C103) shall be installed to control traffic. â€¢ Upon project completion and site stabilization, all construction accesses intended as permanent access for maintenance shall be permanently stabilized. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-8 Driveway shall meet the requirements of the permitting agency It is recommended that the entrance be crowned so that runoff drains off the pad Install driveway culvert if there is a roadside ditch present 4â€™ â€“ 8â€ quarry spalls Geotextile 12â€ min. thickness Provide full width of ingress/egress area Figure 4.1.1 â€“ Stabilized Construction Entrance Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C105. The products did not pass through the Technology Assessment Protocol â€“ Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecologyâ€™s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html BMP C106: Wheel Wash Purpose Wheel washes reduce the amount of sediment transported onto paved roads by motor vehicles. Conditions of Use When a stabilized construction entrance (see BMP C105) is not preventing sediment from being tracked onto pavement. â€¢ Wheel washing is generally an effective BMP when installed with careful attention to topography. For example, a wheel wash can be detrimental if installed at the top of a slope abutting a right-of-way where the water from the dripping truck can run unimpeded into the street. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-9 â€¢ Pressure washing combined with an adequately sized and surfaced pad with direct drainage to a large 10-foot x 10-foot sump can be very effective. â€¢ Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application, or to the sanitary sewer with local sewer district approval. â€¢ Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. Design and Suggested details are shown in Figure 4.1.2. The Local Permitting Installation Authority may allow other designs. A minimum of 6 inches of asphalt Specifications treated base (ATB) over crushed base material or 8 inches over a good subgrade is recommended to pave the wheel wash. Use a low clearance truck to test the wheel wash before paving. Either a belly dump or lowboy will work well to test clearance. Keep the water level from 12 to 14 inches deep to avoid damage to truck hubs and filling the truck tongues with water. Midpoint spray nozzles are only needed in extremely muddy conditions. Wheel wash systems should be designed with a small grade change, 6- to 1-inches for a 10-foot-wide pond, to allow sediment to flow to the low side of pond to help prevent re-suspension of sediment. A drainpipe with a 2- to 3-foot riser should be installed on the low side of the pond to allow for easy cleaning and refilling. Polymers may be used to promote coagulation and flocculation in a closed-loop system. Polyacrylamide (PAM) added to the wheel wash water at a rate of 0.25 - 0.5 pounds per 1,000 gallons of water increases effectiveness and reduces cleanup time. If PAM is already being used for dust or erosion control and is being applied by a water truck, the same truck can be used to change the wash water. Maintenance The wheel wash should start out the day with fresh water. Standards The wash water should be changed a minimum of once per day. On large earthwork jobs where more than 10-20 trucks per hour are expected, the wash water will need to be changed more often. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-10 Figure 4.1.2 â€“ Wheel Wash Notes: 1. Asphalt construction entrance 6 in. asphalt treated base (ATB). 2. 3-inch trash pump with floats on the suction hose. 3. Midpoint spray nozzles, if needed. 4. 6-inch sewer pipe with butterfly valves. Bottom one is a drain. Locate top pipeâ€™s invert 1 foot above bottom of wheel wash. 5. 8 foot x 8 foot sump with 5 feet of catch. Build so the sump can be cleaned with a trackhoe. 6. Asphalt curb on the low road side to direct water back to pond. 7. 6-inch sleeve under road. 8. Ball valves. 9. 15 foot. ATB apron to protect ground from splashing water. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-11 BMP C107: Construction Road/Parking Area Stabilization Purpose Stabilizing subdivision roads, parking areas, and other on-site vehicle transportation routes immediately after grading reduces erosion caused by construction traffic or runoff. Conditions of Use Roads or parking areas shall be stabilized wherever they are constructed, whether permanent or temporary, for use by construction traffic. â€¢ High Visibility Fencing (see BMP C103) shall be installed, if necessary, to limit the access of vehicles to only those roads and parking areas that are stabilized. Design and â€¢ On areas that will receive asphalt as part of the project, install the first Installation lift as soon as possible. Specifications â€¢ A 6-inch depth of 2- to 4-inch crushed rock, gravel base, or crushed surfacing base course shall be applied immediately after grading or utility installation. A 4-inch course of asphalt treated base (ATB) may also be used, or the road/parking area may be paved. It may also be possible to use cement or calcium chloride for soil stabilization. If cement or cement kiln dust is used for roadbase stabilization, pH monitoring and BMPs (BMPs C252 and C253) are necessary to evaluate and minimize the effects on stormwater. If the area will not be used for permanent roads, parking areas, or structures, a 6-inch depth of hog fuel may also be used, but this is likely to require more maintenance. Whenever possible, construction roads and parking areas shall be placed on a firm, compacted subgrade. â€¢ Temporary road gradients shall not exceed 15 percent. Roadways shall be carefully graded to drain. Drainage ditches shall be provided on each side of the roadway in the case of a crowned section, or on one side in the case of a super-elevated section. Drainage ditches shall be directed to a sediment control BMP. â€¢ Rather than relying on ditches, it may also be possible to grade the road so that runoff sheet-flows into a heavily vegetated area with a well-developed topsoil. Landscaped areas are not adequate. If this area has at least 50 feet of vegetation that water can flow through, then it is generally preferable to use the vegetation to treat runoff, rather than a sediment pond or trap. The 50 feet shall not include wetlands or their buffers. If runoff is allowed to sheetflow through adjacent vegetated areas, it is vital to design the roadways and parking areas so that no concentrated runoff is created. â€¢ Storm drain inlets shall be protected to prevent sediment-laden water entering the storm drain system (see BMP C220). Maintenance Inspect stabilized areas regularly, especially after large storm events. Standards Crushed rock, gravel base, etc. shall be added as required to maintain a Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-12 stable driving surface and to stabilize any areas that have eroded. Following construction, these areas shall be restored to pre-construction condition or better to prevent future erosion. Perform street cleaning at the end of each day or more often if necessary. BMP C120: Temporary and Permanent Seeding Purpose Seeding reduces erosion by stabilizing exposed soils. A well-established vegetative cover is one of the most effective methods of reducing erosion. Conditions of Use Use seeding throughout the project on disturbed areas that have reached final grade or that will remain unworked for more than 30 days. The optimum seeding windows for western Washington are April 1 through June 30 and September 1 through October 1. Between July 1 and August 30 seeding requires irrigation until 75 percent grass cover is established. Between October 1 and March 30 seeding requires a cover of mulch with straw or an erosion control blanket until 75 percent grass cover is established. Review all disturbed areas in late August to early September and complete all seeding by the end of September. Otherwise, vegetation will not establish itself enough to provide more than average protection. â€¢ Mulch is required at all times for seeding because it protects seeds from heat, moisture loss, and transport due to runoff. Mulch can be applied on top of the seed or simultaneously by hydroseeding. See BMP C121: Mulching for specifications. â€¢ Seed and mulch, all disturbed areas not otherwise vegetated at final site stabilization. Final stabilization means the completion of all soil disturbing activities at the site and the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (such as pavement, riprap, gabions or geotextiles) which will prevent erosion. Design and Seed retention/detention ponds as required. Installation Install channels intended for vegetation before starting major Specifications earthwork and hydroseed with a Bonded Fiber Matrix. For vegetated channels that will have high flows, install erosion control blankets over hydroseed. Before allowing water to flow in vegetated channels, establish 75 percent vegetation cover. If vegetated channels cannot be established by seed before water flow; install sod in the channel bottomâ€”over hydromulch and erosion control blankets. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-13 â€¢ Confirm the installation of all required surface water control measures to prevent seed from washing away. â€¢ Hydroseed applications shall include a minimum of 1,500 pounds per acre of mulch with 3 percent tackifier. See BMP C121: Mulching for specifications. â€¢ Areas that will have seeding only and not landscaping may need compost or meal-based mulch included in the hydroseed in order to establish vegetation. Re-install native topsoil on the disturbed soil surface before application. â€¢ When installing seed via hydroseeding operations, only about 1/3 of the seed actually ends up in contact with the soil surface. This reduces the ability to establish a good stand of grass quickly. To overcome this, consider increasing seed quantities by up to 50 percent. â€¢ Enhance vegetation establishment by dividing the hydromulch operation into two phases: 1. Phase 1- Install all seed and fertilizer with 25-30 percent mulch and tackifier onto soil in the first lift. 2. Phase 2- Install the rest of the mulch and tackifier over the first lift. Or, enhance vegetation by: 1. Installing the mulch, seed, fertilizer, and tackifier in one lift. 2. Spread or blow straw over the top of the hydromulch at a rate of 800-1000 pounds per acre. 3. Hold straw in place with a standard tackifier. Both of these approaches will increase cost moderately but will greatly improve and enhance vegetative establishment. The increased cost may be offset by the reduced need for: â€¢ Irrigation. â€¢ Reapplication of mulch. â€¢ Repair of failed slope surfaces. This technique works with standard hydromulch (1,500 pounds per acre minimum) and BFM/MBFMs (3,000 pounds per acre minimum). â€¢ Seed may be installed by hand if: â€¢ Temporary and covered by straw, mulch, or topsoil. â€¢ Permanent in small areas (usually less than 1 acre) and covered with mulch, topsoil, or erosion blankets. â€¢ The seed mixes listed in the tables below include recommended mixes for both temporary and permanent seeding. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-14 â€¢ Apply these mixes, with the exception of the wetland mix, at a rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow-release fertilizers are used. â€¢ Consult the local suppliers or the local conservation district for their recommendations because the appropriate mix depends on a variety of factors, including location, exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the local authority may be used. â€¢ Other mixes may be appropriate, depending on the soil type and hydrology of the area. â€¢ Table 4.1.2 lists the standard mix for areas requiring a temporary vegetative cover. Table 4.1.2 Temporary Erosion Control Seed Mix % Weight % Purity % Germination Chewings or annual blue grass 40 98 90 Festuca rubra var. commutata or Poa anna Perennial rye - 50 98 90 Lolium perenne Redtop or colonial bentgrass 5 92 85 Agrostis alba or Agrostis tenuis White dutch clover 5 98 90 Trifolium repens â€¢ Table 4.1.3 lists a recommended mix for landscaping seed. Table 4.1.3 Landscaping Seed Mix % Weight % Purity % Germination Perennial rye blend 70 98 90 Lolium perenne Chewings and red fescue blend 30 98 90 Festuca rubra var. commutata or Festuca rubra Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-15 â€¢ Table 4.1.4 lists a turf seed mix for dry situations where there is no need for watering. This mix requires very little maintenance. Table 4.1.4 Low-Growing Turf Seed Mix % Weight % Purity % Germination Dwarf tall fescue (several varieties) 45 98 90 Festuca arundinacea var. Dwarf perennial rye (Barclay) 30 98 90 Lolium perenne var. barclay Red fescue 20 98 90 Festuca rubra Colonial bentgrass 5 98 90 Agrostis tenuis â€¢ Table 4.1.5 lists a mix for bioswales and other intermittently wet areas. Table 4.1.5 Bioswale Seed Mix* % Weight % Purity % Germination Tall or meadow fescue 75-80 98 90 Festuca arundinacea or Festuca elatior Seaside/Creeping bentgrass 10-15 92 85 Agrostis palustris Redtop bentgrass 5-10 90 80 Agrostis alba or Agrostis gigantea * Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-16 â€¢ Table 4.1.6 lists a low-growing, relatively non-invasive seed mix appropriate for very wet areas that are not regulated wetlands. Apply this mixture at a rate of 60 pounds per acre. Consult Hydraulic Permit Authority (HPA) for seed mixes if applicable. Table 4.1.6 Wet Area Seed Mix* % Weight % Purity % Germination Tall or meadow fescue 60-70 98 90 Festuca arundinacea or Festuca elatior Seaside/Creeping bentgrass 10-15 98 85 Agrostis palustris Meadow foxtail 10-15 90 80 Alepocurus pratensis Alsike clover 1-6 98 90 Trifolium hybridum Redtop bentgrass 1-6 92 85 Agrostis alba * Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix â€¢ Table 4.1.7 lists a recommended meadow seed mix for infrequently maintained areas or non-maintained areas where colonization by native plants is desirable. Likely applications include rural road and utility right-of-way. Seeding should take place in September or very early October in order to obtain adequate establishment prior to the winter months. Consider the appropriateness of clover, a fairly invasive species, in the mix. Amending the soil can reduce the need for clover. Table 4.1.7 Meadow Seed Mix % Weight % Purity % Germination Redtop or Oregon bentgrass 20 92 85 Agrostis alba or Agrostis oregonensis Red fescue 70 98 90 Festuca rubra White dutch clover 10 98 90 Trifolium repens Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-17 â€¢ Roughening and Rototilling: â€¢ The seedbed should be firm and rough. Roughen all soil no matter what the slope. Track walk slopes before seeding if engineering purposes require compaction. Backblading or smoothing of slopes greater than 4H:1V is not allowed if they are to be seeded. â€¢ Restoration-based landscape practices require deeper incorporation than that provided by a simple single-pass rototilling treatment. Wherever practical, initially rip the subgrade to improve long-term permeability, infiltration, and water inflow qualities. At a minimum, permanent areas shall use soil amendments to achieve organic matter and permeability performance defined in engineered soil/landscape systems. For systems that are deeper than 8 inches complete the rototilling process in multiple lifts, or prepare the engineered soil system per specifications and place to achieve the specified depth. â€¢ Fertilizers: â€¢ Conducting soil tests to determine the exact type and quantity of fertilizer is recommended. This will prevent the over-application of fertilizer. â€¢ Organic matter is the most appropriate form of fertilizer because it provides nutrients (including nitrogen, phosphorus, and potassium) in the least water-soluble form. â€¢ In general, use 10-4-6 N-P-K (nitrogen-phosphorus-potassium) fertilizer at a rate of 90 pounds per acre. Always use slow-release fertilizers because they are more efficient and have fewer environmental impacts. Do not add fertilizer to the hydromulch machine, or agitate, more than 20 minutes before use. Too much agitation destroys the slow-release coating. â€¢ There are numerous products available that take the place of chemical fertilizers. These include several with seaweed extracts that are beneficial to soil microbes and organisms. If 100 percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be necessary. Cottonseed meal provides a good source of long-term, slow-release, available nitrogen. â€¢ Bonded Fiber Matrix and Mechanically Bonded Fiber Matrix: â€¢ On steep slopes use Bonded Fiber Matrix (BFM) or Mechanically Bonded Fiber Matrix (MBFM) products. Apply BFM/MBFM products at a minimum rate of 3,000 pounds per acre of mulch with approximately 10 percent tackifier. Achieve a minimum of 95 percent soil coverage during application. Numerous products are available commercially. Installed products per manufacturerâ€™s instructions. Most products require 24-36 hours to cure before rainfall and cannot be installed on wet or saturated soils. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-18 Generally, products come in 40-50 pound bags and include all necessary ingredients except for seed and fertilizer. â€¢ BFMs and MBFMs provide good alternatives to blankets in most areas requiring vegetation establishment. Advantages over blankets include: â€¢ BFM and MBFMs do not require surface preparation. â€¢ Helicopters can assist in installing BFM and MBFMs in remote areas. â€¢ On slopes steeper than 2.5H:1V, blanket installers may require ropes and harnesses for safety. â€¢ Installing BFM and MBFMs can save at least $1,000 per acre compared to blankets. Maintenance Reseed any seeded areas that fail to establish at least 80 percent cover Standards (100 percent cover for areas that receive sheet or concentrated flows). If reseeding is ineffective, use an alternate method such as sodding, mulching, or nets/blankets. If winter weather prevents adequate grass growth, this time limit may be relaxed at the discretion of the local authority when sensitive areas would otherwise be protected. â€¢ Reseed and protect by mulch any areas that experience erosion after achieving adequate cover. Reseed and protect by mulch any eroded area. â€¢ Supply seeded areas with adequate moisture, but do not water to the extent that it causes runoff. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C120. The products did not pass through the Technology Assessment Protocol â€“ Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecologyâ€™s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html BMP C121: Mulching Purpose Mulching soils provides immediate temporary protection from erosion. Mulch also enhances plant establishment by conserving moisture, holding fertilizer, seed, and topsoil in place, and moderating soil temperatures. There is an enormous variety of mulches that can be used. This section discusses only the most common types of mulch. As a temporary cover measure, mulch should be used: Conditions of Use â€¢ For less than 30 days on disturbed areas that require cover. â€¢ At all times for seeded areas, especially during the wet season and Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-19 during the hot summer months. â€¢ During the wet season on slopes steeper than 3H:1V with more than 10 feet of vertical relief. Mulch may be applied at any time of the year and must be refreshed periodically. â€¢ For seeded areas mulch may be made up of 100 percent: cottonseed meal; fibers made of wood, recycled cellulose, hemp, kenaf; compost; or blends of these. Tackifier shall be plant-based, such as guar or alpha plantago, or chemical-based such as polyacrylamide or polymers. Any mulch or tackifier product used shall be installed per manufacturerâ€™s instructions. Generally, mulches come in 40-50 pound bags. Seed and fertilizer are added at time of application. Design and For mulch materials, application rates, and specifications, see Table 4.1.8. Installation Always use a 2-inch minimum mulch thickness; increase the thickness Specifications until the ground is 95% covered (i.e. not visible under the mulch layer). Note: Thickness may be increased for disturbed areas in or near sensitive areas or other areas highly susceptible to erosion. Mulch used within the ordinary high-water mark of surface waters should be selected to minimize potential flotation of organic matter. Composted organic materials have higher specific gravities (densities) than straw, wood, or chipped material. Consult Hydraulic Permit Authority (HPA) for mulch mixes if applicable. Maintenance â€¢ The thickness of the cover must be maintained. Standards â€¢ Any areas that experience erosion shall be remulched and/or protected with a net or blanket. If the erosion problem is drainage related, then the problem shall be fixed and the eroded area remulched. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-20 Table 4.1.8 Mulch Standards and Guidelines Application Mulch Material Quality Standards Rates Remarks Straw Air-dried; free from 2"-3" thick; 5 Cost-effective protection when applied with adequate thickness. undesirable seed and bales per 1,000 Hand-application generally requires greater thickness than coarse material. sf or 2-3 tons per blown straw. The thickness of straw may be reduced by half acre when used in conjunction with seeding. In windy areas straw must be held in place by crimping, using a tackifier, or covering with netting. Blown straw always has to be held in place with a tackifier as even light winds will blow it away. Straw, however, has several deficiencies that should be considered when selecting mulch materials. It often introduces and/or encourages the propagation of weed species and it has no significant long- term benefits. It should also not be used within the ordinary high-water elevation of surface waters (due to flotation). Hydromulch No growth Approx. 25-30 Shall be applied with hydromulcher. Shall not be used without inhibiting factors. lbs per 1,000 sf seed and tackifier unless the application rate is at least doubled. or 1,500 - 2,000 Fibers longer than about Â¾-1 inch clog hydromulch equipment. lbs per acre Fibers should be kept to less than Â¾ inch. Composted No visible water or 2" thick min.; More effective control can be obtained by increasing thickness Mulch and dust during approx. 100 tons to 3". Excellent mulch for protecting final grades until Compost handling. Must be per acre (approx. landscaping because it can be directly seeded or tilled into soil produced in 800 lbs per yard) as an amendment. Composted mulch has a coarser size accordance with gradation than compost. It is more stable and practical to use in WAC 173-350, wet areas and during rainy weather conditions. Do not use Solid Waste composted mulch near wetlands or near phosphorous impaired Handling Standards. water bodies. . Chipped Site Average size shall 2" thick min.; This is a cost-effective way to dispose of debris from clearing Vegetation be several inches. and grubbing, and it eliminates the problems associated with Gradations from burning. Generally, it should not be used on slopes above fines to 6 inches in approx. 10% because of its tendency to be transported by length for texture, runoff. It is not recommended within 200 feet of surface waters. variation, and If seeding is expected shortly after mulch, the decomposition of interlocking the chipped vegetation may tie up nutrients important to grass properties. establishment. Wood-based No visible water or 2â€ thick min.; This material is often called â€œhog or hogged fuel.â€ The use of Mulch or Wood dust during approx. 100 tons mulch ultimately improves the organic matter in the soil. Straw handling. Must be per acre (approx. Special caution is advised regarding the source and composition purchased from a 800 lbs. per of wood-based mulches. Its preparation typically does not supplier with a Solid cubic yard) provide any weed seed control, so evidence of residual Waste Handling vegetation in its composition or known inclusion of weed plants Permit or one or seeds should be monitored and prevented (or minimized). exempt from solid waste regulations. Wood Strand A blend of loose, 2â€ thick min. Cost-effective protection when applied with adequate thickness. Mulch long, thin wood A minimum of 95-percent of the wood strand shall have lengths pieces derived from between 2 and 10-inches, with a width and thickness between native conifer or 1/16 and â…œ-inches. The mulch shall not contain resin, tannin, or deciduous trees with other compounds in quantities that would be detrimental to plant high length-to-width life. Sawdust or wood shavings shall not be used as mulch. ratio. (WSDOT specification (9-14.4(4)) Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-21 BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of Plastic covering may be used on disturbed areas that require cover Use measures for less than 30 days, except as stated below. â€¢ Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid breakdown of most polyethylene sheeting makes it unsuitable for long-term (greater than six months) applications. â€¢ Due to rapid runoff caused by plastic covering, do not use this method upslope of areas that might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes. â€¢ Plastic sheeting may result in increased runoff volumes and velocities, requiring additional on-site measures to counteract the increases. Creating a trough with wattles or other material can convey clean water away from these areas. â€¢ To prevent undercutting, trench and backfill rolled plastic covering products. â€¢ While plastic is inexpensive to purchase, the added cost of installation, maintenance, removal, and disposal make this an expensive material, up to $1.50-2.00 per square yard. â€¢ Whenever plastic is used to protect slopes install water collection measures at the base of the slope. These measures include plastic- covered berms, channels, and pipes used to covey clean rainwater away from bare soil and disturbed areas. Do not mix clean runoff from a plastic covered slope with dirty runoff from a project. â€¢ Other uses for plastic include: 1. Temporary ditch liner. 2. Pond liner in temporary sediment pond. 3. Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel being stored. 4. Emergency slope protection during heavy rains. 5. Temporary drainpipe (â€œelephant trunkâ€) used to direct water. Design and â€¢ Plastic slope cover must be installed as follows: Installation 1. Run plastic up and down slope, not across slope. Specifications 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet. 3. Minimum of 8-inch overlap at seams. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-26 4. On long or wide slopes, or slopes subject to wind, tape all seams. 5. Place plastic into a small (12-inch wide by 6-inch deep) slot trench at the top of the slope and backfill with soil to keep water from flowing underneath. 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and tie them together with twine to hold them in place. 7. Inspect plastic for rips, tears, and open seams regularly and repair immediately. This prevents high velocity runoff from contacting bare soil which causes extreme erosion. 8. Sandbags may be lowered into place tied to ropes. However, all sandbags must be staked in place. â€¢ Plastic sheeting shall have a minimum thickness of 0.06 millimeters. â€¢ If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance â€¢ Torn sheets must be replaced and open seams repaired. Standards â€¢ Completely remove and replace the plastic if it begins to deteriorate due to ultraviolet radiation. â€¢ Completely remove plastic when no longer needed. â€¢ Dispose of old tires used to weight down plastic sheeting appropriately. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C123. The products did not pass through the Technology Assessment Protocol â€“ Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecologyâ€™s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html BMP C124: Sodding Purpose The purpose of sodding is to establish permanent turf for immediate erosion protection and to stabilize drainage ways where concentrated overland flow will occur. Conditions of Use Sodding may be used in the following areas: â€¢ Disturbed areas that require short-term or long-term cover. â€¢ Disturbed areas that require immediate vegetative cover. â€¢ All waterways that require vegetative lining. Waterways may also be seeded rather than sodded, and protected with a net or blanket. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-27 Design and Sod shall be free of weeds, of uniform thickness (approximately 1-inch Installation thick), and shall have a dense root mat for mechanical strength. Specifications The following steps are recommended for sod installation: â€¢ Shape and smooth the surface to final grade in accordance with the approved grading plan. The swale needs to be overexcavated 4 to 6 inches below design elevation to allow room for placing soil amendment and sod. â€¢ Amend 4 inches (minimum) of compost into the top 8 inches of the soil if the organic content of the soil is less than ten percent or the permeability is less than 0.6 inches per hour. See http://www.ecy.wa.gov/programs/swfa/organics/soil.html for further information. â€¢ Fertilize according to the supplier's recommendations. â€¢ Work lime and fertilizer 1 to 2 inches into the soil, and smooth the surface. â€¢ Lay strips of sod beginning at the lowest area to be sodded and perpendicular to the direction of water flow. Wedge strips securely into place. Square the ends of each strip to provide for a close, tight fit. Stagger joints at least 12 inches. Staple on slopes steeper than 3H:1V. Staple the upstream edge of each sod strip. â€¢ Roll the sodded area and irrigate. â€¢ When sodding is carried out in alternating strips or other patterns, seed the areas between the sod immediately after sodding. Maintenance If the grass is unhealthy, the cause shall be determined and appropriate Standards action taken to reestablish a healthy groundcover. If it is impossible to establish a healthy groundcover due to frequent saturation, instability, or some other cause, the sod shall be removed, the area seeded with an appropriate mix, and protected with a net or blanket. BMP C125: Topsoiling / Composting Purpose Topsoiling and composting provide a suitable growth medium for final site stabilization with vegetation. While not a permanent cover practice in itself, topsoiling and composting are an integral component of providing permanent cover in those areas where there is an unsuitable soil surface for plant growth. Use this BMP in conjunction with other BMPs such as seeding, mulching, or sodding. Native soils and disturbed soils that have been organically amended not only retain much more stormwater, but they also serve as effective biofilters for urban pollutants and, by supporting more vigorous plant growth, reduce the water, fertilizer and pesticides needed to support Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-28 installed landscapes. Topsoil does not include any subsoils but only the material from the top several inches including organic debris. Conditions of â€¢ Permanent landscaped areas shall contain healthy topsoil that reduces Use the need for fertilizers, improves overall topsoil quality, provides for better vegetal health and vitality, improves hydrologic characteristics, and reduces the need for irrigation. â€¢ Leave native soils and the duff layer undisturbed to the maximum extent practicable. Stripping of existing, properly functioning soil system and vegetation for the purpose of topsoiling during construction is not acceptable. Preserve existing soil systems in undisturbed and uncompacted conditions if functioning properly. â€¢ Areas that already have good topsoil, such as undisturbed areas, do not require soil amendments. â€¢ Restore, to the maximum extent practical, native soils disturbed during clearing and grading to a condition equal to or better than the original site conditionâ€™s moisture-holding capacity. Use on-site native topsoil, incorporate amendments into on-site soil, or import blended topsoil to meet this requirement. â€¢ Topsoiling is a required procedure when establishing vegetation on shallow soils, and soils of critically low pH (high acid) levels. â€¢ Beware of where the topsoil comes from, and what vegetation was on site before disturbance, invasive plant seeds may be included and could cause problems for establishing native plants, landscaped areas, or grasses. â€¢ Topsoil from the site will contain mycorrhizal bacteria that are necessary for healthy root growth and nutrient transfer. These native mycorrhiza are acclimated to the site and will provide optimum conditions for establishing grasses. Use commercially available mycorrhiza products when using off-site topsoil. Design and Meet the following requirements for areas requiring disruption and Installation topsoiling: Specifications â€¢ Maximize the depth of the topsoil wherever possible to provide the maximum possible infiltration capacity and beneficial growth medium. Topsoil shall have: â€¢ A minimum depth of 8-inches. Scarify subsoils below the topsoil layer at least 4-inches with some incorporation of the upper material to avoid stratified layers, where feasible. Ripping or re- structuring the subgrade may also provide additional benefits regarding the overall infiltration and interflow dynamics of the soil system. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-29 â€¢ A minimum organic content of 10% dry weight, and 5% organic matter content in turf areas. Incorporate organic amendments to a minimum 8-inch depth except where tree roots or other natural features limit the depth of incorporation. â€¢ A pH between 6.0 and 8.0 or matching the pH of the undisturbed soil. â€¢ If blended topsoil is imported, then fines should be limited to 25 percent passing through a 200 sieve. â€¢ Accomplish the required organic content and pH by either returning native topsoil to the site and/or incorporating organic amendments. â€¢ To meet the organic content use compost that meets the definition of â€œcomposted materialsâ€ in WAC 173-350-220. This code is available online at: http://apps.leg.wa.gov/WAC/default.aspx?cite=173-350-220. The compost must also have an organic matter content of 35% to 65%, and a carbon to nitrogen ratio below 25H:1V. The carbon to nitrogen ratio may be as high as 35H:1V for plantings composed entirely of plants native to the Puget Sound Lowlands region. â€¢ For till soils use a mixture of approximately two parts soil to one part compost. This equates to 4 inches of compost mixed to a depth of 12 inches in till soils. Increasing the concentration of compost beyond this level can have negative effects on vegetal health, while decreasing the concentrations can reduce the benefits of amended soils. â€¢ Gravel or cobble outwash soils, may require different approaches. Organics and fines easily migrate through the loose structure of these soils. Therefore, the importation of at least 6 inches of quality topsoil, underlain by some type of filter fabric to prevent the migration of fines, may be more appropriate for these soils. â€¢ The final composition and construction of the soil system will result in a natural selection or favoring of certain plant species over time. For example, incorporation of topsoil may favor grasses, while layering with mildly acidic, high-carbon amendments may favor more woody vegetation. â€¢ Allow sufficient time in scheduling for topsoil spreading prior to seeding, sodding, or planting. â€¢ Take care when applying top soil to subsoils with contrasting textures. Sandy topsoil over clayey subsoil is a particularly poor combination, as water creeps along the junction between the soil layers and causes the topsoil to slough. If topsoil and subsoil are not properly bonded, water will not infiltrate the soil profile evenly and it will be difficult to Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-30 establish vegetation. The best method to prevent a lack of bonding is to actually work the topsoil into the layer below for a depth of at least 6 inches. â€¢ Field exploration of the site shall be made to determine if there is surface soil of sufficient quantity and quality to justify stripping. Topsoil shall be friable and loamy (loam, sandy loam, silt loam, sandy clay loam, and clay loam). Avoid areas of natural ground water recharge. â€¢ Stripping shall be confined to the immediate construction area. A 4- inch to 6-inch stripping depth is common, but depth may vary depending on the particular soil. All surface runoff control structures shall be in place prior to stripping. â€¢ Do not place topsoil while in a frozen or muddy condition, when the subgrade is excessively wet, or when conditions exist that may otherwise be detrimental to proper grading or proposed sodding or seeding. â€¢ In any areas requiring grading remove and stockpile the duff layer and topsoil on site in a designated, controlled area, not adjacent to public resources and critical areas. Stockpiled topsoil is to be reapplied to other portions of the site where feasible. â€¢ Locate the topsoil stockpile so that it meets specifications and does not interfere with work on the site. It may be possible to locate more than one pile in proximity to areas where topsoil will be used. Stockpiling of topsoil shall occur in the following manner: â€¢ Side slopes of the stockpile shall not exceed 2H:1V. â€¢ Between October 1 and April 30: â€¢ An interceptor dike with gravel outlet and silt fence shall surround all topsoil. â€¢ Within 2 days complete erosion control seeding, or covering stockpiles with clear plastic, or other mulching materials. â€¢ Between May 1 and September 30: â€¢ An interceptor dike with gravel outlet and silt fence shall surround all topsoil if the stockpile will remain in place for a longer period of time than active construction grading. â€¢ Within 7 days complete erosion control seeding, or covering stockpiles with clear plastic, or other mulching materials. â€¢ When native topsoil is to be stockpiled and reused the following should apply to ensure that the mycorrhizal bacterial, earthworms, and other beneficial organisms will not be destroyed: 1. Re-install topsoil within 4 to 6 weeks. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-31 2. Do not allow the saturation of topsoil with water. 3. Do not use plastic covering. Maintenance â€¢ Inspect stockpiles regularly, especially after large storm events. Standards Stabilize any areas that have eroded. â€¢ Establish soil quality and depth toward the end of construction and once established, protect from compaction, such as from large machinery use, and from erosion. â€¢ Plant and mulch soil after installation. â€¢ Leave plant debris or its equivalent on the soil surface to replenish organic matter. â€¢ Reduce and adjust, where possible, the use of irrigation, fertilizers, herbicides and pesticides, rather than continuing to implement formerly established practices. BMP C126: Polyacrylamide (PAM) for Soil Erosion Protection Purpose Polyacrylamide (PAM) is used on construction sites to prevent soil erosion. Applying PAM to bare soil in advance of a rain event significantly reduces erosion and controls sediment in two ways. First, PAM increases the soilâ€™s available pore volume, thus increasing infiltration through flocculation and reducing the quantity of stormwater runoff. Second, it increases flocculation of suspended particles and aids in their deposition, thus reducing stormwater runoff turbidity and improving water quality. Conditions of Use PAM shall not be directly applied to water or allowed to enter a water body. In areas that drain to a sediment pond, PAM can be applied to bare soil under the following conditions: â€¢ During rough grading operations. â€¢ In Staging areas. â€¢ Balanced cut and fill earthwork. â€¢ Haul roads prior to placement of crushed rock surfacing. â€¢ Compacted soil roadbase. â€¢ Stockpiles. â€¢ After final grade and before paving or final seeding and planting. â€¢ Pit sites. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-32 BMP C140: Dust Control Purpose Dust control prevents wind transport of dust from disturbed soil surfaces onto roadways, drainage ways, and surface waters. Conditions of Use â€¢ In areas (including roadways) subject to surface and air movement of dust where on-site and off-site impacts to roadways, drainage ways, or surface waters are likely. Design and â€¢ Vegetate or mulch areas that will not receive vehicle traffic. In areas Installation where planting, mulching, or paving is impractical, apply gravel or Specifications landscaping rock. â€¢ Limit dust generation by clearing only those areas where immediate activity will take place, leaving the remaining area(s) in the original condition. Maintain the original ground cover as long as practical. â€¢ Construct natural or artificial windbreaks or windscreens. These may be designed as enclosures for small dust sources. â€¢ Sprinkle the site with water until surface is wet. Repeat as needed. To prevent carryout of mud onto street, refer to Stabilized Construction Entrance (BMP C105). â€¢ Irrigation water can be used for dust control. Irrigation systems should be installed as a first step on sites where dust control is a concern. â€¢ Spray exposed soil areas with a dust palliative, following the manufacturerâ€™s instructions and cautions regarding handling and application. Used oil is prohibited from use as a dust suppressant. Local governments may approve other dust palliatives such as calcium chloride or PAM. â€¢ PAM (BMP C126) added to water at a rate of 0.5 lbs. per 1,000 gallons of water per acre and applied from a water truck is more effective than water alone. This is due to increased infiltration of water into the soil and reduced evaporation. In addition, small soil particles are bonded together and are not as easily transported by wind. Adding PAM may actually reduce the quantity of water needed for dust control. Use of PAM could be a cost-effective dust control method. Techniques that can be used for unpaved roads and lots include: â€¢ Lower speed limits. High vehicle speed increases the amount of dust stirred up from unpaved roads and lots. â€¢ Upgrade the road surface strength by improving particle size, shape, and mineral types that make up the surface and base materials. â€¢ Add surface gravel to reduce the source of dust emission. Limit the amount of fine particles (those smaller than .075 mm) to 10 to 20 percent. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-40 â€¢ Use geotextile fabrics to increase the strength of new roads or roads undergoing reconstruction. â€¢ Encourage the use of alternate, paved routes, if available. â€¢ Restrict use of paved roadways by tracked vehicles and heavy trucks to prevent damage to road surface and base. â€¢ Apply chemical dust suppressants using the admix method, blending the product with the top few inches of surface material. Suppressants may also be applied as surface treatments. â€¢ Pave unpaved permanent roads and other trafficked areas. â€¢ Use vacuum street sweepers. â€¢ Remove mud and other dirt promptly so it does not dry and then turn into dust. â€¢ Limit dust-causing work on windy days. â€¢ Contact your local Air Pollution Control Authority for guidance and training on other dust control measures. Compliance with the local Air Pollution Control Authority constitutes compliance with this BMP. Maintenance Respray area as necessary to keep dust to a minimum. Standards BMP C150: Materials on Hand Purpose Keep quantities of erosion prevention and sediment control materials on the project site at all times to be used for regular maintenance and emergency situations such as unexpected heavy summer rains. Having these materials on-site reduces the time needed to implement BMPs when inspections indicate that existing BMPs are not meeting the Construction SWPPP requirements. In addition, contractors can save money by buying some materials in bulk and storing them at their office or yard. Conditions of Use â€¢ Construction projects of any size or type can benefit from having materials on hand. A small commercial development project could have a roll of plastic and some gravel available for immediate protection of bare soil and temporary berm construction. A large earthwork project, such as highway construction, might have several tons of straw, several rolls of plastic, flexible pipe, sandbags, geotextile fabric and steel â€œTâ€ posts. â€¢ Materials are stockpiled and readily available before any site clearing, grubbing, or earthwork begins. A large contractor or developer could keep a stockpile of materials that are available for use on several projects. â€¢ If storage space at the project site is at a premium, the contractor could maintain the materials at their office or yard. The office or yard must be less than an hour from the project site. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-41 Design and Depending on project type, size, complexity, and length, materials and Installation quantities will vary. A good minimum list of items that will cover Specifications numerous situations includes: Material Clear Plastic, 6 mil Drainpipe, 6 or 8 inch diameter Sandbags, filled Straw Bales for mulching, Quarry Spalls Washed Gravel Geotextile Fabric Catch Basin Inserts Steel â€œTâ€ Posts Silt fence material Straw Wattles Maintenance â€¢ All materials with the exception of the quarry spalls, steel â€œTâ€ posts, Standards and gravel should be kept covered and out of both sun and rain. â€¢ Re-stock materials used as needed. BMP C151: Concrete Handling Purpose Concrete work can generate process water and slurry that contain fine particles and high pH, both of which can violate water quality standards in the receiving water. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Use this BMP to minimize and eliminate concrete, concrete process water, and concrete slurry from entering waters of the state. Conditions of Use Any time concrete is used, utilize these management practices. Concrete construction projects include, but are not limited to, the following: â€¢ Curbs â€¢ Sidewalks â€¢ Roads â€¢ Bridges â€¢ Foundations â€¢ Floors â€¢ Runways Design and â€¢ Wash out concrete truck chutes, pumps, and internals into formed Installation areas only. Assure that washout of concrete trucks is performed off- Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-42 Specifications site or in designated concrete washout areas. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Refer to BMP C154 for information on concrete washout areas. â€¢ Return unused concrete remaining in the truck and pump to the originating batch plant for recycling. Do not dump excess concrete on site, except in designated concrete washout areas. â€¢ Wash off hand tools including, but not limited to, screeds, shovels, rakes, floats, and trowels into formed areas only. â€¢ Wash equipment difficult to move, such as concrete pavers in areas that do not directly drain to natural or constructed stormwater conveyances. â€¢ Do not allow washdown from areas, such as concrete aggregate driveways, to drain directly to natural or constructed stormwater conveyances. â€¢ Contain washwater and leftover product in a lined container when no formed areas are available,. Dispose of contained concrete in a manner that does not violate ground water or surface water quality standards. â€¢ Always use forms or solid barriers for concrete pours, such as pilings, within 15-feet of surface waters. â€¢ Refer to BMPs C252 and C253 for pH adjustment requirements. â€¢ Refer to the Construction Stormwater General Permit for pH monitoring requirements if the project involves one of the following activities: â€¢ Significant concrete work (greater than 1,000 cubic yards poured concrete or recycled concrete used over the life of a project). â€¢ The use of engineered soils amended with (but not limited to) Portland cement-treated base, cement kiln dust or fly ash. â€¢ Discharging stormwater to segments of water bodies on the 303(d) list (Category 5) for high pH. Maintenance Check containers for holes in the liner daily during concrete pours and Standards repair the same day. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-43 BMP C152: Sawcutting and Surfacing Pollution Prevention Purpose Sawcutting and surfacing operations generate slurry and process water that contains fine particles and high pH (concrete cutting), both of which can violate the water quality standards in the receiving water. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Use this BMP to minimize and eliminate process water and slurry created through sawcutting or surfacing from entering waters of the State. Conditions of Use Utilize these management practices anytime sawcutting or surfacing operations take place. Sawcutting and surfacing operations include, but are not limited to, the following: â€¢ Sawing â€¢ Coring â€¢ Grinding â€¢ Roughening â€¢ Hydro-demolition â€¢ Bridge and road surfacing Design and â€¢ Vacuum slurry and cuttings during cutting and surfacing operations. Installation â€¢ Slurry and cuttings shall not remain on permanent concrete or asphalt Specifications pavement overnight. â€¢ Slurry and cuttings shall not drain to any natural or constructed drainage conveyance including stormwater systems. This may require temporarily blocking catch basins. â€¢ Dispose of collected slurry and cuttings in a manner that does not violate ground water or surface water quality standards. â€¢ Do not allow process water generated during hydro-demolition, surface roughening or similar operations to drain to any natural or constructed drainage conveyance including stormwater systems. Dispose process water in a manner that does not violate ground water or surface water quality standards. â€¢ Handle and dispose cleaning waste material and demolition debris in a manner that does not cause contamination of water. Dispose of sweeping material from a pick-up sweeper at an appropriate disposal site. Maintenance Continually monitor operations to determine whether slurry, cuttings, or Standards process water could enter waters of the state. If inspections show that a violation of water quality standards could occur, stop operations and immediately implement preventive measures such as berms, barriers, secondary containment, and vacuum trucks. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-44 BMP C153: Material Delivery, Storage and Containment Purpose Prevent, reduce, or eliminate the discharge of pollutants to the stormwater system or watercourses from material delivery and storage. Minimize the storage of hazardous materials on-site, store materials in a designated area, and install secondary containment. Conditions of Use These procedures are suitable for use at all construction sites with delivery and storage of the following materials: â€¢ Petroleum products such as fuel, oil and grease â€¢ Soil stabilizers and binders (e.g. Polyacrylamide) â€¢ Fertilizers, pesticides and herbicides â€¢ Detergents â€¢ Asphalt and concrete compounds â€¢ Hazardous chemicals such as acids, lime, adhesives, paints, solvents and curing compounds â€¢ Any other material that may be detrimental if released to the environment Design and The following steps should be taken to minimize risk: Installation â€¢ Temporary storage area should be located away from vehicular traffic, Specifications near the construction entrance(s), and away from waterways or storm drains. â€¢ Material Safety Data Sheets (MSDS) should be supplied for all materials stored. Chemicals should be kept in their original labeled containers. â€¢ Hazardous material storage on-site should be minimized. â€¢ Hazardous materials should be handled as infrequently as possible. â€¢ During the wet weather season (Oct 1 â€“ April 30), consider storing materials in a covered area. â€¢ Materials should be stored in secondary containments, such as earthen dike, horse trough, or even a childrenâ€™s wading pool for non-reactive materials such as detergents, oil, grease, and paints. Small amounts of material may be secondarily contained in â€œbus boyâ€ trays or concrete mixing trays. â€¢ Do not store chemicals, drums, or bagged materials directly on the ground. Place these items on a pallet and, when possible, and within secondary containment. â€¢ If drums must be kept uncovered, store them at a slight angle to reduce ponding of rainwater on the lids to reduce corrosion. Domed plastic covers are inexpensive and snap to the top of drums, preventing water from collecting. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-45 Material Storage Areas and Secondary Containment Practices: â€¢ Liquids, petroleum products, and substances listed in 40 CFR Parts 110, 117, or 302 shall be stored in approved containers and drums and shall not be overfilled. Containers and drums shall be stored in temporary secondary containment facilities. â€¢ Temporary secondary containment facilities shall provide for a spill containment volume able to contain 10% of the total enclosed container volume of all containers, or 110% of the capacity of the largest container within its boundary, whichever is greater. â€¢ Secondary containment facilities shall be impervious to the materials stored therein for a minimum contact time of 72 hours. â€¢ Secondary containment facilities shall be maintained free of accumulated rainwater and spills. In the event of spills or leaks, accumulated rainwater and spills shall be collected and placed into drums. These liquids shall be handled as hazardous waste unless testing determines them to be non-hazardous. â€¢ Sufficient separation should be provided between stored containers to allow for spill cleanup and emergency response access. â€¢ During the wet weather season (Oct 1 â€“ April 30), each secondary containment facility shall be covered during non-working days, prior to and during rain events. â€¢ Keep material storage areas clean, organized and equipped with an ample supply of appropriate spill clean-up material (spill kit). â€¢ The spill kit should include, at a minimum: â€¢ 1-Water Resistant Nylon Bag â€¢ 3-Oil Absorbent Socks 3â€x 4â€™ â€¢ 2-Oil Absorbent Socks 3â€x 10â€™ â€¢ 12-Oil Absorbent Pads 17â€x19â€ â€¢ 1-Pair Splash Resistant Goggles â€¢ 3-Pair Nitrile Gloves â€¢ 10-Disposable Bags with Ties â€¢ Instructions Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-46 BMP C154: Concrete Washout Area Purpose Prevent or reduce the discharge of pollutants to stormwater from concrete waste by conducting washout off-site, or performing on-site washout in a designated area to prevent pollutants from entering surface waters or ground water. Conditions of Use Concrete washout area best management practices are implemented on construction projects where: â€¢ Concrete is used as a construction material â€¢ It is not possible to dispose of all concrete wastewater and washout off-site (ready mix plant, etc.). â€¢ Concrete trucks, pumpers, or other concrete coated equipment are washed on-site. â€¢ Note: If less than 10 concrete trucks or pumpers need to be washed out on-site, the washwater may be disposed of in a formed area awaiting concrete or an upland disposal site where it will not contaminate surface or ground water. The upland disposal site shall be at least 50 feet from sensitive areas such as storm drains, open ditches, or water bodies, including wetlands. Design and Implementation Installation The following steps will help reduce stormwater pollution from concrete Specifications wastes: â€¢ Perform washout of concrete trucks off-site or in designated concrete washout areas only. â€¢ Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. â€¢ Do not allow excess concrete to be dumped on-site, except in designated concrete washout areas. â€¢ Concrete washout areas may be prefabricated concrete washout containers, or self-installed structures (above-grade or below-grade). â€¢ Prefabricated containers are most resistant to damage and protect against spills and leaks. Companies may offer delivery service and provide regular maintenance and disposal of solid and liquid waste. â€¢ If self-installed concrete washout areas are used, below-grade structures are preferred over above-grade structures because they are less prone to spills and leaks. â€¢ Self-installed above-grade structures should only be used if excavation is not practical. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-47 Education â€¢ Discuss the concrete management techniques described in this BMP with the ready-mix concrete supplier before any deliveries are made. â€¢ Educate employees and subcontractors on the concrete waste management techniques described in this BMP. â€¢ Arrange for contractorâ€™s superintendent or Certified Erosion and Sediment Control Lead (CESCL) to oversee and enforce concrete waste management procedures. â€¢ A sign should be installed adjacent to each temporary concrete washout facility to inform concrete equipment operators to utilize the proper facilities. Contracts Incorporate requirements for concrete waste management into concrete supplier and subcontractor agreements. Location and Placement â€¢ Locate washout area at least 50 feet from sensitive areas such as storm drains, open ditches, or water bodies, including wetlands. â€¢ Allow convenient access for concrete trucks, preferably near the area where the concrete is being poured. â€¢ If trucks need to leave a paved area to access washout, prevent track- out with a pad of rock or quarry spalls (see BMP C105). These areas should be far enough away from other construction traffic to reduce the likelihood of accidental damage and spills. â€¢ The number of facilities you install should depend on the expected demand for storage capacity. â€¢ On large sites with extensive concrete work, washouts should be placed in multiple locations for ease of use by concrete truck drivers. On-site Temporary Concrete Washout Facility, Transit Truck Washout Procedures: â€¢ Temporary concrete washout facilities shall be located a minimum of 50 ft from sensitive areas including storm drain inlets, open drainage facilities, and watercourses. See Figures 4.1.7 and 4.1.8. â€¢ Concrete washout facilities shall be constructed and maintained in sufficient quantity and size to contain all liquid and concrete waste generated by washout operations. â€¢ Approximately 7 gallons of wash water are used to wash one truck chute. â€¢ Approximately 50 gallons are used to wash out the hopper of a concrete pump truck. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-48 â€¢ Washout of concrete trucks shall be performed in designated areas only. â€¢ Concrete washout from concrete pumper bins can be washed into concrete pumper trucks and discharged into designated washout area or properly disposed of off-site. â€¢ Once concrete wastes are washed into the designated area and allowed to harden, the concrete should be broken up, removed, and disposed of per applicable solid waste regulations. Dispose of hardened concrete on a regular basis. â€¢ Temporary Above-Grade Concrete Washout Facility â€¢ Temporary concrete washout facility (type above grade) should be constructed as shown on the details below, with a recommended minimum length and minimum width of 10 ft, but with sufficient quantity and volume to contain all liquid and concrete waste generated by washout operations. â€¢ Plastic lining material should be a minimum of 10 mil polyethylene sheeting and should be free of holes, tears, or other defects that compromise the impermeability of the material. â€¢ Temporary Below-Grade Concrete Washout Facility â€¢ Temporary concrete washout facilities (type below grade) should be constructed as shown on the details below, with a recommended minimum length and minimum width of 10 ft. The quantity and volume should be sufficient to contain all liquid and concrete waste generated by washout operations. â€¢ Lath and flagging should be commercial type. â€¢ Plastic lining material shall be a minimum of 10 mil polyethylene sheeting and should be free of holes, tears, or other defects that compromise the impermeability of the material. â€¢ Liner seams shall be installed in accordance with manufacturersâ€™ recommendations. â€¢ Soil base shall be prepared free of rocks or other debris that may cause tears or holes in the plastic lining material. Maintenance Inspection and Maintenance Standards â€¢ Inspect and verify that concrete washout BMPs are in place prior to the commencement of concrete work. â€¢ During periods of concrete work, inspect daily to verify continued performance. â€¢ Check overall condition and performance. â€¢ Check remaining capacity (% full). Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-49 â€¢ If using self-installed washout facilities, verify plastic liners are intact and sidewalls are not damaged. â€¢ If using prefabricated containers, check for leaks. â€¢ Washout facilities shall be maintained to provide adequate holding capacity with a minimum freeboard of 12 inches. â€¢ Washout facilities must be cleaned, or new facilities must be constructed and ready for use once the washout is 75% full. â€¢ If the washout is nearing capacity, vacuum and dispose of the waste material in an approved manner. â€¢ Do not discharge liquid or slurry to waterways, storm drains or directly onto ground. â€¢ Do not use sanitary sewer without local approval. â€¢ Place a secure, non-collapsing, non-water collecting cover over the concrete washout facility prior to predicted wet weather to prevent accumulation and overflow of precipitation. â€¢ Remove and dispose of hardened concrete and return the structure to a functional condition. Concrete may be reused on-site or hauled away for disposal or recycling. â€¢ When you remove materials from the self-installed concrete washout, build a new structure; or, if the previous structure is still intact, inspect for signs of weakening or damage, and make any necessary repairs. Re-line the structure with new plastic after each cleaning. Removal of Temporary Concrete Washout Facilities â€¢ When temporary concrete washout facilities are no longer required for the work, the hardened concrete, slurries and liquids shall be removed and properly disposed of. â€¢ Materials used to construct temporary concrete washout facilities shall be removed from the site of the work and disposed of or recycled. â€¢ Holes, depressions or other ground disturbance caused by the removal of the temporary concrete washout facilities shall be backfilled, repaired, and stabilized to prevent erosion. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-50 Figure 4.1.7a â€“ Concrete Washout Area Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-51 Figure 4.1.7b â€“ Concrete Washout Area Figure 4.1.8 â€“ Prefabricated Concrete Washout Container w/Ramp Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-52 BMP C160: Certified Erosion and Sediment Control Lead Purpose The project proponent designates at least one person as the responsible representative in charge of erosion and sediment control (ESC), and water quality protection. The designated person shall be the Certified Erosion and Sediment Control Lead (CESCL) who is responsible for ensuring compliance with all local, state, and federal erosion and sediment control and water quality requirements. Conditions of Use A CESCL shall be made available on projects one acre or larger that discharge stormwater to surface waters of the state. Sites less than one acre may have a person without CESCL certification conduct inspections; sampling is not required on sites that disturb less than an acre. â€¢ The CESCL shall: â€¢ Have a current certificate proving attendance in an erosion and sediment control training course that meets the minimum ESC training and certification requirements established by Ecology (see details below). Ecology will maintain a list of ESC training and certification providers at: http://www.ecy.wa.gov/programs/wq/stormwater/cescl.html OR â€¢ Be a Certified Professional in Erosion and Sediment Control (CPESC); for additional information go to: www.cpesc.net Specifications â€¢ Certification shall remain valid for three years. â€¢ The CESCL shall have authority to act on behalf of the contractor or developer and shall be available, or on-call, 24 hours per day throughout the period of construction. â€¢ The Construction SWPPP shall include the name, telephone number, fax number, and address of the designated CESCL. â€¢ A CESCL may provide inspection and compliance services for multiple construction projects in the same geographic region. Duties and responsibilities of the CESCL shall include, but are not limited to the following: â€¢ Maintaining permit file on site at all times which includes the Construction SWPPP and any associated permits and plans. â€¢ Directing BMP installation, inspection, maintenance, modification, and removal. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-53 â€¢ Updating all project drawings and the Construction SWPPP with changes made. â€¢ Completing any sampling requirements including reporting results using WebDMR. â€¢ Keeping daily logs, and inspection reports. Inspection reports should include: â€¢ Inspection date/time. â€¢ Weather information; general conditions during inspection and approximate amount of precipitation since the last inspection. â€¢ A summary or list of all BMPs implemented, including observations of all erosion/sediment control structures or practices. The following shall be noted: 1. Locations of BMPs inspected. 2. Locations of BMPs that need maintenance. 3. Locations of BMPs that failed to operate as designed or intended. 4. Locations of where additional or different BMPs are required. â€¢ Visual monitoring results, including a description of discharged stormwater. The presence of suspended sediment, turbid water, discoloration, and oil sheen shall be noted, as applicable. â€¢ Any water quality monitoring performed during inspection. â€¢ General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. â€¢ Facilitate, participate in, and take corrective actions resulting from inspections performed by outside agencies or the owner. BMP C162: Scheduling Purpose Sequencing a construction project reduces the amount and duration of soil exposed to erosion by wind, rain, runoff, and vehicle tracking. Conditions of Use The construction sequence schedule is an orderly listing of all major land- disturbing activities together with the necessary erosion and sedimentation control measures planned for the project. This type of schedule guides the contractor on work to be done before other work is started so that serious erosion and sedimentation problems can be avoided. Following a specified work schedule that coordinates the timing of land- disturbing activities and the installation of control measures is perhaps the most cost-effective way of controlling erosion during construction. The removal of surface ground cover leaves a site vulnerable to accelerated Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-54 erosion. Construction procedures that limit land clearing provide timely installation of erosion and sedimentation controls, and restore protective cover quickly can significantly reduce the erosion potential of a site. Design â€¢ Minimize construction during rainy periods. Considerations â€¢ Schedule projects to disturb only small portions of the site at any one time. Complete grading as soon as possible. Immediately stabilize the disturbed portion before grading the next portion. Practice staged seeding in order to revegetate cut and fill slopes as the work progresses. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-55 BMP C200: Interceptor Dike and Swale Purpose Provide a ridge of compacted soil, or a ridge with an upslope swale, at the top or base of a disturbed slope or along the perimeter of a disturbed construction area to convey stormwater. Use the dike and/or swale to intercept the runoff from unprotected areas and direct it to areas where erosion can be controlled. This can prevent storm runoff from entering the work area or sediment-laden runoff from leaving the construction site. Conditions of Use Where the runoff from an exposed site or disturbed slope must be conveyed to an erosion control facility which can safely convey the stormwater. â€¢ Locate upslope of a construction site to prevent runoff from entering disturbed area. â€¢ When placed horizontally across a disturbed slope, it reduces the amount and velocity of runoff flowing down the slope. â€¢ Locate downslope to collect runoff from a disturbed area and direct water to a sediment basin. Design and â€¢ Dike and/or swale and channel must be stabilized with temporary or Installation permanent vegetation or other channel protection during construction. Specifications â€¢ Channel requires a positive grade for drainage; steeper grades require channel protection and check dams. â€¢ Review construction for areas where overtopping may occur. â€¢ Can be used at top of new fill before vegetation is established. â€¢ May be used as a permanent diversion channel to carry the runoff. â€¢ Sub-basin tributary area should be one acre or less. â€¢ Design capacity for the peak flow from a 10-year, 24-hour storm, assuming a Type 1A rainfall distribution, for temporary facilities. Alternatively, use 1.6 times the 10-year, 1-hour flow indicated by an approved continuous runoff model. For facilities that will also serve on a permanent basis, consult the local governmentâ€™s drainage requirements. Interceptor dikes shall meet the following criteria: Top Width 2 feet minimum. Height 1.5 feet minimum on berm. Side Slope 2H:1V or flatter. Grade Depends on topography, however, dike system minimum is 0.5%, and maximum is 1%. Compaction Minimum of 90 percent ASTM D698 standard proctor. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-57 Horizontal Spacing of Interceptor Dikes: Average Slope Slope Percent Flowpath Length 20H:1V or less 3-5% 300 feet (10 to 20)H:1V 5-10% 200 feet (4 to 10)H:1V 10-25% 100 feet (2 to 4)H:1V 25-50% 50 feet Stabilization depends on velocity and reach Slopes <5% Seed and mulch applied within 5 days of dike construction (see BMP C121, Mulching). Slopes 5 - 40% Dependent on runoff velocities and dike materials. Stabilization should be done immediately using either sod or riprap or other measures to avoid erosion. â€¢ The upslope side of the dike shall provide positive drainage to the dike outlet. No erosion shall occur at the outlet. Provide energy dissipation measures as necessary. Sediment-laden runoff must be released through a sediment trapping facility. â€¢ Minimize construction traffic over temporary dikes. Use temporary cross culverts for channel crossing. Interceptor swales shall meet the following criteria: Bottom Width 2 feet minimum; the cross-section bottom shall be level. Depth 1-foot minimum. Side Slope 2H:1V or flatter. Grade Maximum 5 percent, with positive drainage to a suitable outlet (such as a sediment pond). Stabilization Seed as per BMP C120, Temporary and Permanent Seeding, or BMP C202, Channel Lining, 12 inches thick riprap pressed into the bank and extending at least 8 inches vertical from the bottom. â€¢ Inspect diversion dikes and interceptor swales once a week and after every rainfall. Immediately remove sediment from the flow area. â€¢ Damage caused by construction traffic or other activity must be repaired before the end of each working day. Check outlets and make timely repairs as needed to avoid gully formation. When the area below the temporary diversion dike is permanently stabilized, remove the dike and fill and stabilize the channel to blend with the natural surface. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-58 Figure 4.2.6 â€“ Detail of Level Spreader BMP C207: Check Dams Purpose Construction of small dams across a swale or ditch reduces the velocity of concentrated flow and dissipates energy at the check dam. Conditions of Use Where temporary channels or permanent channels are not yet vegetated, channel lining is infeasible, and/or velocity checks are required. â€¢ Check dams may not be placed in streams unless approved by the State Department of Fish and Wildlife. Check dams may not be placed in wetlands without approval from a permitting agency. â€¢ Do not place check dams below the expected backwater from any salmonid bearing water between October 1 and May 31 to ensure that there is no loss of high flow refuge habitat for overwintering juvenile salmonids and emergent salmonid fry. â€¢ Construct rock check dams from appropriately sized rock. The rock used must be large enough to stay in place given the expected design flow through the channel. The rock must be placed by hand or by mechanical means (no dumping of rock to form dam) to achieve complete coverage of the ditch or swale and to ensure that the center of the dam is lower than the edges. â€¢ Check dams may also be constructed of either rock or pea-gravel filled bags. Numerous new products are also available for this purpose. They tend to be re-usable, quick and easy to install, effective, and cost efficient. â€¢ Place check dams perpendicular to the flow of water. â€¢ The dam should form a triangle when viewed from the side. This prevents undercutting as water flows over the face of the dam rather than falling directly onto the ditch bottom. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-73 â€¢ Before installing check dams impound and bypass upstream water flow away from the work area. Options for bypassing include pumps, siphons, or temporary channels. â€¢ Check dams in association with sumps work more effectively at slowing flow and retaining sediment than just a check dam alone. A deep sump should be provided immediately upstream of the check dam. â€¢ In some cases, if carefully located and designed, check dams can remain as permanent installations with very minor regrading. They may be left as either spillways, in which case accumulated sediment would be graded and seeded, or as check dams to prevent further sediment from leaving the site. â€¢ The maximum spacing between the dams shall be such that the toe of the upstream dam is at the same elevation as the top of the downstream dam. â€¢ Keep the maximum height at 2 feet at the center of the dam. â€¢ Keep the center of the check dam at least 12 inches lower than the outer edges at natural ground elevation. â€¢ Keep the side slopes of the check dam at 2H:1V or flatter. â€¢ Key the stone into the ditch banks and extend it beyond the abutments a minimum of 18 inches to avoid washouts from overflow around the dam. â€¢ Use filter fabric foundation under a rock or sand bag check dam. If a blanket ditch liner is used, filter fabric is not necessary. A piece of organic or synthetic blanket cut to fit will also work for this purpose. â€¢ In the case of grass-lined ditches and swales, all check dams and accumulated sediment shall be removed when the grass has matured sufficiently to protect the ditch or swale - unless the slope of the swale is greater than 4 percent. The area beneath the check dams shall be seeded and mulched immediately after dam removal. â€¢ Ensure that channel appurtenances, such as culvert entrances below check dams, are not subject to damage or blockage from displaced stones. Figure 4.2.7 depicts a typical rock check dam. Maintenance Check dams shall be monitored for performance and sediment Standards accumulation during and after each runoff producing rainfall. Sediment shall be removed when it reaches one half the sump depth. â€¢ Anticipate submergence and deposition above the check dam and erosion from high flows around the edges of the dam. â€¢ If significant erosion occurs between dams, install a protective riprap liner in that portion of the channel. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-74 Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C207. The products did not pass through the Technology Assessment Protocol â€“ Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecologyâ€™s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-75 Figure 4.2.7 â€“ Rock Check Dam Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-76 Standards accumulation during and after each runoff producing rainfall. Sediment shall be removed when it reaches one half the height of the dam. â€¢ Anticipate submergence and deposition above the triangular silt dam and erosion from high flows around the edges of the dam. Immediately repair any damage or any undercutting of the dam. BMP C209: Outlet Protection Purpose Outlet protection prevents scour at conveyance outlets and minimizes the potential for downstream erosion by reducing the velocity of concentrated stormwater flows. Conditions of use Outlet protection is required at the outlets of all ponds, pipes, ditches, or other conveyances, and where runoff is conveyed to a natural or manmade drainage feature such as a stream, wetland, lake, or ditch. Design and The receiving channel at the outlet of a culvert shall be protected from Installation erosion by rock lining a minimum of 6 feet downstream and extending up Specifications the channel sides a minimum of 1â€“foot above the maximum tailwater elevation or 1-foot above the crown, whichever is higher. For large pipes (more than 18 inches in diameter), the outlet protection lining of the channel is lengthened to four times the diameter of the culvert. â€¢ Standard wingwalls, and tapered outlets and paved channels should also be considered when appropriate for permanent culvert outlet protection. (See WSDOT Hydraulic Manual, available through WSDOT Engineering Publications). â€¢ Organic or synthetic erosion blankets, with or without vegetation, are usually more effective than rock, cheaper, and easier to install. Materials can be chosen using manufacturer product specifications. ASTM test results are available for most products and the designer can choose the correct material for the expected flow. â€¢ With low flows, vegetation (including sod) can be effective. â€¢ The following guidelines shall be used for riprap outlet protection: 1. If the discharge velocity at the outlet is less than 5 fps (pipe slope less than 1 percent), use 2-inch to 8-inch riprap. Minimum thickness is 1-foot. 2. For 5 to 10 fps discharge velocity at the outlet (pipe slope less than 3 percent), use 24-inch to 48-inch riprap. Minimum thickness is 2 feet. 3. For outlets at the base of steep slope pipes (pipe slope greater than 10 percent), an engineered energy dissipater shall be used. â€¢ Filter fabric or erosion control blankets should always be used under riprap to prevent scour and channel erosion. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-78 â€¢ New pipe outfalls can provide an opportunity for low-cost fish habitat improvements. For example, an alcove of low-velocity water can be created by constructing the pipe outfall and associated energy dissipater back from the stream edge and digging a channel, over- widened to the upstream side, from the outfall. Overwintering juvenile and migrating adult salmonids may use the alcove as shelter during high flows. Bank stabilization, bioengineering, and habitat features may be required for disturbed areas. This work may require a HPA. See Volume V for more information on outfall system design. Maintenance â€¢ Inspect and repair as needed. Standards â€¢ Add rock as needed to maintain the intended function. â€¢ Clean energy dissipater if sediment builds up. BMP C220: Storm Drain Inlet Protection Purpose Storm drain inlet protection prevents coarse sediment from entering drainage systems prior to permanent stabilization of the disturbed area. Conditions of Use Use storm drain inlet protection at inlets that are operational before permanent stabilization of the disturbed drainage area. Provide protection for all storm drain inlets downslope and within 500 feet of a disturbed or construction area, unless conveying runoff entering catch basins to a sediment pond or trap. Also consider inlet protection for lawn and yard drains on new home construction. These small and numerous drains coupled with lack of gutters in new home construction can add significant amounts of sediment into the roof drain system. If possible delay installing lawn and yard drains until just before landscaping or cap these drains to prevent sediment from entering the system until completion of landscaping. Provide 18-inches of sod around each finished lawn and yard drain. Table 4.2.2 lists several options for inlet protection. All of the methods for storm drain inlet protection tend to plug and require a high frequency of maintenance. Limit drainage areas to one acre or less. Possibly provide emergency overflows with additional end-of-pipe treatment where stormwater ponding would cause a hazard. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-79 Table 4.2.2 Storm Drain Inlet Protection Applicable for Type of Inlet Emergency Paved/ Earthen Protection Overflow Surfaces Conditions of Use Drop Inlet Protection Excavated drop inlet Yes, Earthen Applicable for heavy flows. Easy protection temporary to maintain. Large area flooding will Requirement: 30â€™ X 30â€™/acre occur Block and gravel drop Yes Paved or Earthen Applicable for heavy concentrated inlet protection flows. Will not pond. Gravel and wire drop No Applicable for heavy concentrated inlet protection flows. Will pond. Can withstand traffic. Catch basin filters Yes Paved or Earthen Frequent maintenance required. Curb Inlet Protection Curb inlet protection Small capacity Paved Used for sturdy, more compact with a wooden weir overflow installation. Block and gravel curb Yes Paved Sturdy, but limited filtration. inlet protection Culvert Inlet Protection Culvert inlet sediment 18 month expected life. trap Design and Excavated Drop Inlet Protection - An excavated impoundment around the Installation storm drain. Sediment settles out of the stormwater prior to entering the Specifications storm drain. â€¢ Provide a depth of 1-2 ft as measured from the crest of the inlet structure. â€¢ Slope sides of excavation no steeper than 2H:1V. â€¢ Minimum volume of excavation 35 cubic yards. â€¢ Shape basin to fit site with longest dimension oriented toward the longest inflow area. â€¢ Install provisions for draining to prevent standing water problems. â€¢ Clear the area of all debris. â€¢ Grade the approach to the inlet uniformly. â€¢ Drill weep holes into the side of the inlet. â€¢ Protect weep holes with screen wire and washed aggregate. â€¢ Seal weep holes when removing structure and stabilizing area. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-80 â€¢ Build a temporary dike, if necessary, to the down slope side of the structure to prevent bypass flow. Block and Gravel Filter - A barrier formed around the storm drain inlet with standard concrete blocks and gravel. See Figure 4.2.8. â€¢ Provide a height of 1 to 2 feet above inlet. â€¢ Recess the first row 2-inches into the ground for stability. â€¢ Support subsequent courses by placing a 2x4 through the block opening. â€¢ Do not use mortar. â€¢ Lay some blocks in the bottom row on their side for dewatering the pool. â€¢ Place hardware cloth or comparable wire mesh with Â½-inch openings over all block openings. â€¢ Place gravel just below the top of blocks on slopes of 2H:1V or flatter. â€¢ An alternative design is a gravel donut. â€¢ Provide an inlet slope of 3H:1V. â€¢ Provide an outlet slope of 2H:1V. â€¢ Provide a1-foot wide level stone area between the structure and the inlet. â€¢ Use inlet slope stones 3 inches in diameter or larger. â€¢ Use gravel Â½- to Â¾-inch at a minimum thickness of 1-foot for the outlet slope. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-81 Ponding Height Notes: 1. Drop inlet sediment barriers are to be used for small, nearly level drainage areas. (less than 5%) 2. Excavate a basin of sufficient size adjacent to the drop inlet. 3. The top of the structure (ponding height) must be well below the ground elevation downslope to prevent runoff from bypassing the inlet. A temporary dike may be necessary on the downslope side of the structure. Figure 4.2.8 â€“ Block and Gravel Filter Gravel and Wire Mesh Filter - A gravel barrier placed over the top of the inlet. This structure does not provide an overflow. â€¢ Use a hardware cloth or comparable wire mesh with Â½-inch openings. â€¢ Use coarse aggregate. â€¢ Provide a height 1-foot or more, 18-inches wider than inlet on all sides. â€¢ Place wire mesh over the drop inlet so that the wire extends a minimum of 1-foot beyond each side of the inlet structure. â€¢ Overlap the strips if more than one strip of mesh is necessary. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-82 â€¢ Place coarse aggregate over the wire mesh. â€¢ Provide at least a 12-inch depth of gravel over the entire inlet opening and extend at least 18-inches on all sides. Catchbasin Filters â€“ Use inserts designed by manufacturers for construction sites. The limited sediment storage capacity increases the amount of inspection and maintenance required, which may be daily for heavy sediment loads. To reduce maintenance requirements combine a catchbasin filter with another type of inlet protection. This type of inlet protection provides flow bypass without overflow and therefore may be a better method for inlets located along active rights-of-way. â€¢ Provides 5 cubic feet of storage. â€¢ Requires dewatering provisions. â€¢ Provides a high-flow bypass that will not clog under normal use at a construction site. â€¢ Insert the catchbasin filter in the catchbasin just below the grating. Curb Inlet Protection with Wooden Weir â€“ Barrier formed around a curb inlet with a wooden frame and gravel. â€¢ Use wire mesh with Â½-inch openings. â€¢ Use extra strength filter cloth. â€¢ Construct a frame. â€¢ Attach the wire and filter fabric to the frame. â€¢ Pile coarse washed aggregate against wire/fabric. â€¢ Place weight on frame anchors. Block and Gravel Curb Inlet Protection â€“ Barrier formed around a curb inlet with concrete blocks and gravel. See Figure 4.2.9. â€¢ Use wire mesh with Â½-inch openings. â€¢ Place two concrete blocks on their sides abutting the curb at either side of the inlet opening. These are spacer blocks. â€¢ Place a 2x4 stud through the outer holes of each spacer block to align the front blocks. â€¢ Place blocks on their sides across the front of the inlet and abutting the spacer blocks. â€¢ Place wire mesh over the outside vertical face. â€¢ Pile coarse aggregate against the wire to the top of the barrier. Curb and Gutter Sediment Barrier â€“ Sandbag or rock berm (riprap and aggregate) 3 feet high and 3 feet wide in a horseshoe shape. See Figure 4.2.10. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-83 â€¢ Construct a horseshoe shaped berm, faced with coarse aggregate if using riprap, 3 feet high and 3 feet wide, at least 2 feet from the inlet. â€¢ Construct a horseshoe shaped sedimentation trap on the outside of the berm sized to sediment trap standards for protecting a culvert inlet. Maintenance â€¢ Inspect catch basin filters frequently, especially after storm events. Standards Clean and replace clogged inserts. For systems with clogged stone filters: pull away the stones from the inlet and clean or replace. An alternative approach would be to use the clogged stone as fill and put fresh stone around the inlet. â€¢ Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C220. The products did not pass through the Technology Assessment Protocol â€“ Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecologyâ€™s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-84 Plan View Back of Sidewalk A Catch Basin 2x4 Wood Stud Back of Curb Concrete Block Curb Inlet Wire Screen or Filter Fabric Concrete Block Section A - A Â¾" Drain Gravel (20mm) Â¾" Drain Gravel (20mm) Ponding Height Concrete Block Overflow Curb Inlet Wire Screen or Filter Fabric Catch Basin 2x4 Wood Stud (100x50 Timber Stud) NOTES: 1. Use block and gravel type sediment barrier when curb inlet is located in gently sloping street segment, where water can pond and allow sediment to separate from runoff. 2. Barrier shall allow for overflow from severe storm event. 3. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. Figure 4.2.9 â€“ Block and Gravel Curb Inlet Protection Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-85 Figure 4.2.10 â€“ Curb and Gutter Barrier Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-86 BMP C232: Gravel Filter Berm Purpose A gravel filter berm is constructed on rights-of-way or traffic areas within a construction site to retain sediment by using a filter berm of gravel or crushed rock. Conditions of Use Where a temporary measure is needed to retain sediment from rights-of- way or in traffic areas on construction sites. Design and â€¢ Berm material shall be Â¾ to 3 inches in size, washed well-grade gravel Installation or crushed rock with less than 5 percent fines. Specifications â€¢ Spacing of berms: âˆ’ Every 300 feet on slopes less than 5 percent âˆ’ Every 200 feet on slopes between 5 percent and 10 percent âˆ’ Every 100 feet on slopes greater than 10 percent â€¢ Berm dimensions: âˆ’ 1 foot high with 3H:1V side slopes âˆ’ 8 linear feet per 1 cfs runoff based on the 10-year, 24-hour design storm Maintenance â€¢ Regular inspection is required. Sediment shall be removed and filter Standards material replaced as needed. BMP C233: Silt Fence Purpose Use of a silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. See Figure 4.2.12 for details on silt fence construction. Conditions of Use Silt fence may be used downslope of all disturbed areas. â€¢ Silt fence shall prevent soil carried by runoff water from going beneath, through, or over the top of the silt fence, but shall allow the water to pass through the fence. â€¢ Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial amounts of overland flow. Convey any concentrated flows through the drainage system to a sediment pond. â€¢ Do not construct silt fences in streams or use in V-shaped ditches. Silt fences do not provide an adequate method of silt control for anything deeper than sheet or overland flow. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-88 Figure 4.2.12 â€“ Silt Fence Design and â€¢ Use in combination with sediment basins or other BMPs. Installation â€¢ Maximum slope steepness (normal (perpendicular) to fence line) Specifications 1H:1V. â€¢ Maximum sheet or overland flow path length to the fence of 100 feet. â€¢ Do not allow flows greater than 0.5 cfs. â€¢ The geotextile used shall meet the following standards. All geotextile properties listed below are minimum average roll values (i.e., the test result for any sampled roll in a lot shall meet or exceed the values shown in Table 4.2.3): Table 4.2.3 Geotextile Standards Polymeric Mesh AOS 0.60 mm maximum for slit film woven (#30 sieve). 0.30 (ASTM D4751) mm maximum for all other geotextile types (#50 sieve). 0.15 mm minimum for all fabric types (#100 sieve). Water Permittivity 0.02 sec-1 minimum (ASTM D4491) Grab Tensile Strength 180 lbs. Minimum for extra strength fabric. (ASTM D4632) 100 lbs minimum for standard strength fabric. Grab Tensile Strength 30% maximum (ASTM D4632) Ultraviolet Resistance 70% minimum (ASTM D4355) â€¢ Support standard strength fabrics with wire mesh, chicken wire, 2-inch x 2-inch wire, safety fence, or jute mesh to increase the strength of the Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-89 fabric. Silt fence materials are available that have synthetic mesh backing attached. â€¢ Filter fabric material shall contain ultraviolet ray inhibitors and stabilizers to provide a minimum of six months of expected usable construction life at a temperature range of 0Â°F. to 120Â°F. â€¢ One-hundred percent biodegradable silt fence is available that is strong, long lasting, and can be left in place after the project is completed, if permitted by local regulations. â€¢ Refer to Figure 4.2.12 for standard silt fence details. Include the following standard Notes for silt fence on construction plans and specifications: 1. The contractor shall install and maintain temporary silt fences at the locations shown in the Plans. 2. Construct silt fences in areas of clearing, grading, or drainage prior to starting those activities. 3. The silt fence shall have a 2-feet min. and a 2Â½-feet max. height above the original ground surface. 4. The filter fabric shall be sewn together at the point of manufacture to form filter fabric lengths as required. Locate all sewn seams at support posts. Alternatively, two sections of silt fence can be overlapped, provided the Contractor can demonstrate, to the satisfaction of the Engineer, that the overlap is long enough and that the adjacent fence sections are close enough together to prevent silt laden water from escaping through the fence at the overlap. 5. Attach the filter fabric on the up-slope side of the posts and secure with staples, wire, or in accordance with the manufacturer's recommendations. Attach the filter fabric to the posts in a manner that reduces the potential for tearing. 6. Support the filter fabric with wire or plastic mesh, dependent on the properties of the geotextile selected for use. If wire or plastic mesh is used, fasten the mesh securely to the up-slope side of the posts with the filter fabric up-slope of the mesh. 7. Mesh support, if used, shall consist of steel wire with a maximum mesh spacing of 2-inches, or a prefabricated polymeric mesh. The strength of the wire or polymeric mesh shall be equivalent to or greater than 180 lbs. grab tensile strength. The polymeric mesh must be as resistant to the same level of ultraviolet radiation as the filter fabric it supports. 8. Bury the bottom of the filter fabric 4-inches min. below the ground surface. Backfill and tamp soil in place over the buried portion of the filter fabric, so that no flow can pass beneath the fence and Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-90 scouring cannot occur. When wire or polymeric back-up support mesh is used, the wire or polymeric mesh shall extend into the ground 3-inches min. 9. Drive or place the fence posts into the ground 18-inches min. A 12â€“inch min. depth is allowed if topsoil or other soft subgrade soil is not present and 18-inches cannot be reached. Increase fence post min. depths by 6 inches if the fence is located on slopes of 3H:1V or steeper and the slope is perpendicular to the fence. If required post depths cannot be obtained, the posts shall be adequately secured by bracing or guying to prevent overturning of the fence due to sediment loading. 10. Use wood, steel or equivalent posts. The spacing of the support posts shall be a maximum of 6-feet. Posts shall consist of either: â€¢ Wood with dimensions of 2-inches by 2-inches wide min. and a 3-feet min. length. Wood posts shall be free of defects such as knots, splits, or gouges. â€¢ No. 6 steel rebar or larger. â€¢ ASTM A 120 steel pipe with a minimum diameter of 1-inch. â€¢ U, T, L, or C shape steel posts with a minimum weight of 1.35 lbs./ft. â€¢ Other steel posts having equivalent strength and bending resistance to the post sizes listed above. 11. Locate silt fences on contour as much as possible, except at the ends of the fence, where the fence shall be turned uphill such that the silt fence captures the runoff water and prevents water from flowing around the end of the fence. 12. If the fence must cross contours, with the exception of the ends of the fence, place gravel check dams perpendicular to the back of the fence to minimize concentrated flow and erosion. The slope of the fence line where contours must be crossed shall not be steeper than 3H:1V. â€¢ Gravel check dams shall be approximately 1-foot deep at the back of the fence. Gravel check dams shall be continued perpendicular to the fence at the same elevation until the top of the check dam intercepts the ground surface behind the fence. â€¢ Gravel check dams shall consist of crushed surfacing base course, gravel backfill for walls, or shoulder ballast. Gravel check dams shall be located every 10 feet along the fence where the fence must cross contours. â€¢ Refer to Figure 4.2.13 for slicing method details. Silt fence installation using the slicing method specifications: Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-91 1. The base of both end posts must be at least 2- to 4-inches above the top of the filter fabric on the middle posts for ditch checks to drain properly. Use a hand level or string level, if necessary, to mark base points before installation. 2. Install posts 3- to 4-feet apart in critical retention areas and 6- to 7- feet apart in standard applications. 3. Install posts 24-inches deep on the downstream side of the silt fence, and as close as possible to the filter fabric, enabling posts to support the filter fabric from upstream water pressure. 4. Install posts with the nipples facing away from the filter fabric. 5. Attach the filter fabric to each post with three ties, all spaced within the top 8-inches of the filter fabric. Attach each tie diagonally 45 degrees through the filter fabric, with each puncture at least 1-inch vertically apart. Each tie should be positioned to hang on a post nipple when tightening to prevent sagging. 6. Wrap approximately 6-inches of fabric around the end posts and secure with 3 ties. 7. No more than 24-inches of a 36-inch filter fabric is allowed above ground level. Compact the soil immediately next to the filter fabric with the front wheel of the tractor, skid steer, or roller exerting at least 60 pounds per square inch. Compact the upstream side first and then each side twice for a total of four trips. Check and correct the silt fence installation for any deviation before compaction. Use a flat-bladed shovel to tuck fabric deeper into the ground if necessary. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-92 Figure 4.2.13 â€“ Silt Fence Installation by Slicing Method Maintenance â€¢ Repair any damage immediately. Standards â€¢ Intercept and convey all evident concentrated flows uphill of the silt fence to a sediment pond. â€¢ Check the uphill side of the fence for signs of the fence clogging and acting as a barrier to flow and then causing channelization of flows parallel to the fence. If this occurs, replace the fence or remove the trapped sediment. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-93 â€¢ Remove sediment deposits when the deposit reaches approximately one-third the height of the silt fence, or install a second silt fence. â€¢ Replace filter fabric that has deteriorated due to ultraviolet breakdown. BMP C234: Vegetated Strip Purpose Vegetated strips reduce the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use â€¢ Vegetated strips may be used downslope of all disturbed areas. â€¢ Vegetated strips are not intended to treat concentrated flows, nor are they intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to a sediment pond. The only circumstance in which overland flow can be treated solely by a strip, rather than by a sediment pond, is when the following criteria are met (see Table 4.2.4): Table 4.2.4 Contributing Drainage Area for Vegetated Strips Average Contributing Average Contributing area Max Contributing area Slope Percent Slope area Flowpath Length 1.5H:1V or flatter 67% or flatter 100 feet 2H:1V or flatter 50% or flatter 115 feet 4H:1V or flatter 25% or flatter 150 feet 6H:1V or flatter 16.7% or flatter 200 feet 10H:1V or flatter 10% or flatter 250 feet Design and â€¢ The vegetated strip shall consist of a minimum of a 25-foot flowpath Installation length continuous strip of dense vegetation with topsoil. Grass- Specifications covered, landscaped areas are generally not adequate because the volume of sediment overwhelms the grass. Ideally, vegetated strips shall consist of undisturbed native growth with a well-developed soil that allows for infiltration of runoff. â€¢ The slope within the strip shall not exceed 4H:1V. â€¢ The uphill boundary of the vegetated strip shall be delineated with clearing limits. Maintenance â€¢ Any areas damaged by erosion or construction activity shall be Standards seeded immediately and protected by mulch. â€¢ If more than 5 feet of the original vegetated strip width has had vegetation removed or is being eroded, sod must be installed. â€¢ If there are indications that concentrated flows are traveling across the buffer, surface water controls must be installed to reduce the flows Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-94 entering the buffer, or additional perimeter protection must be installed. BMP C235: Wattles Purpose Wattles are temporary erosion and sediment control barriers consisting of straw, compost, or other material that is wrapped in biodegradable tubular plastic or similar encasing material. They reduce the velocity and can spread the flow of rill and sheet runoff, and can capture and retain sediment. Wattles are typically 8 to 10 inches in diameter and 25 to 30 feet in length. Wattles are placed in shallow trenches and staked along the contour of disturbed or newly constructed slopes. See Figure 4.2.14 for typical construction details. WSDOT Standard Plan I-30.30-00 also provides information on Wattles (http://www.wsdot.wa.gov/Design/Standards/Plans.htm#SectionI) Conditions of Use â€¢ Use wattles: â€¢ In disturbed areas that require immediate erosion protection. â€¢ On exposed soils during the period of short construction delays, or over winter months. â€¢ On slopes requiring stabilization until permanent vegetation can be established. â€¢ The material used dictates the effectiveness period of the wattle. Generally, Wattles are typically effective for one to two seasons. â€¢ Prevent rilling beneath wattles by properly entrenching and abutting wattles together to prevent water from passing between them. Design Criteria â€¢ Install wattles perpendicular to the flow direction and parallel to the slope contour. â€¢ Narrow trenches should be dug across the slope on contour to a depth of 3- to 5-inches on clay soils and soils with gradual slopes. On loose soils, steep slopes, and areas with high rainfall, the trenches should be dug to a depth of 5- to 7- inches, or 1/2 to 2/3 of the thickness of the wattle. â€¢ Start building trenches and installing wattles from the base of the slope and work up. Spread excavated material evenly along the uphill slope and compacted using hand tamping or other methods. â€¢ Construct trenches at intervals of 10- to 25-feet depending on the steepness of the slope, soil type, and rainfall. The steeper the slope the closer together the trenches. â€¢ Install the wattles snugly into the trenches and abut tightly end to end. Do not overlap the ends. â€¢ Install stakes at each end of the wattle, and at 4-foot centers along entire length of wattle. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-95 â€¢ If required, install pilot holes for the stakes using a straight bar to drive holes through the wattle and into the soil. â€¢ Wooden stakes should be approximately 3/4 x 3/4 x 24 inches min. Willow cuttings or 3/8-inch rebar can also be used for stakes. â€¢ Stakes should be driven through the middle of the wattle, leaving 2 to 3 inches of the stake protruding above the wattle. Maintenance â€¢ Wattles may require maintenance to ensure they are in contact with Standards soil and thoroughly entrenched, especially after significant rainfall on steep sandy soils. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-96 Figure 4.2.14 â€“ Wattles Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-97 â€¢ Inspect the slope after significant storms and repair any areas where wattles are not tightly abutted or water has scoured beneath the wattles. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C235. The products did not pass through the Technology Assessment Protocol â€“ Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecologyâ€™s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html BMP C236: Vegetative Filtration Purpose Vegetative Filtration may be used in conjunction with BMP C241 Temporary Sediment Ponds, BMP C206 Level Spreader and a pumping system with surface intake to improve turbidity levels of stormwater discharges by filtering through existing vegetation where undisturbed forest floor duff layer or established lawn with thatch layer are present. Vegetative Filtration can also be used to infiltrate dewatering waste from foundations, vaults, and trenches as long as runoff does not occur. Conditions of Use â€¢ For every five acre of disturbed soil use one acre of grass field, farm pasture, or wooded area. Reduce or increase this area depending on project size, ground water table height, and other site conditions. â€¢ Wetlands shall not be used for filtration. â€¢ Do not use this BMP in areas with a high ground water table, or in areas that will have a high seasonal ground water table during the use of this BMP. â€¢ This BMP may be less effective on soils that prevent the infiltration of the water, such as hard till. â€¢ Using other effective source control measures throughout a construction site will prevent the generation of additional highly turbid water and may reduce the time period or area need for this BMP. â€¢ Stop distributing water into the vegetated area if standing water or erosion results. Design Criteria â€¢ Find land adjacent to the project that has a vegetated field, preferably a farm field, or wooded area. â€¢ If the project site does not contain enough vegetated field area consider obtaining permission from adjacent landowners (especially for farm fields). â€¢ Install a pump and downstream distribution manifold depending on the project size. Generally, the main distribution line should reach 100 to 200-feet long (many large projects, or projects on tight soil, will Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-98 require systems that reach several thousand feet long with numerous branch lines off of the main distribution line). â€¢ The manifold should have several valves, allowing for control over the distribution area in the field. â€¢ Install several branches of 4â€ schedule 20, swaged-fit common septic tight-lined sewer line, or 6â€ fire hose, which can convey the turbid water out to various sections of the field. See Figure 4.2.15. â€¢ Determine the branch length based on the field area geography and number of branches. Typically, branches stretch from 200-feet to several thousand feet. Always, lay branches on contour with the slope. â€¢ On uneven ground, sprinklers perform well. Space sprinkler heads so that spray patterns do not overlap. â€¢ On relatively even surfaces, a level spreader using 4-inch perforated pipe may be used as an alternative option to the sprinkler head setup. Install drain pipe at the highest point on the field and at various lower elevations to ensure full coverage of the filtration area. Pipe should be place with the holes up to allow for a gentle weeping of stormwater evenly out all holes. Leveling the pipe by staking and using sandbags may be required. â€¢ To prevent the over saturation of the field area, rotate the use of branches or spray heads. Do this as needed based on monitoring the spray field. â€¢ Monitor the spray field on a daily basis to ensure that over saturation of any portion of the field doesnâ€™t occur at any time. The presence of standing puddles of water or creation of concentrated flows visually signify that over saturation of the field has occurred. â€¢ Since the operator is handling contaminated water, physically monitor the vegetated spray field all the way down to the nearest surface water, or furthest spray area, to ensure that the water has not caused overland or concentrated flows, and has not created erosion around the spray nozzle. â€¢ Monitoring usually needs to take place 3-5 times per day to ensure sheet-flow into state waters. Do not exceed water quality standards for turbidity. â€¢ Ecology strongly recommends that a separate inspection log be developed, maintained and kept with the existing site logbook to aid the operator conducting inspections. This separate â€œField Filtration Logbookâ€ can also aid the facility in demonstrating compliance with permit conditions. Maintenance â€¢ Inspect the spray nozzles daily, at a minimum, for leaks and plugging Standards from sediment particles. Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-99 â€¢ If erosion, concentrated flows, or over saturation of the field occurs, rotate the use of branches or spray heads or move the branches to a new field location. â€¢ Check all branches and the manifold for unintended leaks. Flowpath Guidelines for Vegetative Filtration Average Slope Average Area % Slope Estimated Flowpath Length (ft) 1.5H:1V 67% 250 2H:1V 50% 200 4H:1V 25% 150 6H:1V 16.7% 115 10H:1V 10% 100 Figure 4.2.15 â€“ Manifold and Braches in a wooded, vegetated spray field Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-100 BMP C241: Temporary Sediment Pond Purpose Sediment ponds remove sediment from runoff originating from disturbed areas of the site. Sediment ponds are typically designed to remove sediment no smaller than medium silt (0.02 mm). Consequently, they usually reduce turbidity only slightly. Conditions of Use Prior to leaving a construction site, stormwater runoff must pass through a sediment pond or other appropriate sediment removal best management practice. A sediment pond shall be used where the contributing drainage area is 3 acres or more. Ponds must be used in conjunction with erosion control practices to reduce the amount of sediment flowing into the basin. Design and â€¢ Sediment basins must be installed only on sites where failure of the Installation structure would not result in loss of life, damage to homes or Specifications buildings, or interruption of use or service of public roads or utilities. Also, sediment traps and ponds are attractive to children and can be very dangerous. Compliance with local ordinances regarding health and safety must be addressed. If fencing of the pond is required, the type of fence and its location shall be shown on the ESC plan. â€¢ Structures having a maximum storage capacity at the top of the dam of 10 acre-ft (435,600 ft3) or more are subject to the Washington Dam Safety Regulations (Chapter 173-175 WAC). â€¢ See Figures 4.2.18, 4.2.19, and 4.2.20 for details. â€¢ If permanent runoff control facilities are part of the project, they should be used for sediment retention. The surface area requirements of the sediment basin must be met. This may require temporarily enlarging the permanent basin to comply with the surface area requirements. The permanent control structure must be temporarily replaced with a control structure that only allows water to leave the pond from the surface or by pumping. The permanent control structure must be installed after the site is fully stabilized. . â€¢ Use of infiltration facilities for sedimentation basins during construction tends to clog the soils and reduce their capacity to infiltrate. If infiltration facilities are to be used, the sides and bottom of the facility must only be rough excavated to a minimum of 2 feet above final grade. Final grading of the infiltration facility shall occur only when all contributing drainage areas are fully stabilized. The infiltration pretreatment facility should be fully constructed and used with the sedimentation basin to help prevent clogging. â€¢ Determining Pond Geometry Obtain the discharge from the hydrologic calculations of the peak flow for the 2-year runoff event (Q2). The 10-year peak flow shall be used if Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-104 the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used. Determine the required surface area at the top of the riser pipe with the equation: SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow See BMP C240 for more information on the derivation of the surface area calculation. The basic geometry of the pond can now be determined using the following design criteria: â€¢ Required surface area SA (from Step 2 above) at top of riser. â€¢ Minimum 3.5-foot depth from top of riser to bottom of pond. â€¢ Maximum 3H:1V interior side slopes and maximum 2H:1V exterior slopes. The interior slopes can be increased to a maximum of 2H:1V if fencing is provided at or above the maximum water surface. â€¢ One foot of freeboard between the top of the riser and the crest of the emergency spillway. â€¢ Flat bottom. â€¢ Minimum 1-foot deep spillway. â€¢ Length-to-width ratio between 3:1 and 6:1. â€¢ Sizing of Discharge Mechanisms. The outlet for the basin consists of a combination of principal and emergency spillways. These outlets must pass the peak runoff expected from the contributing drainage area for a 100-year storm. If, due to site conditions and basin geometry, a separate emergency spill- way is not feasible, the principal spillway must pass the entire peak runoff expected from the 100-year storm. However, an attempt to provide a separate emergency spillway should always be made. The runoff calculations should be based on the site conditions during construction. The flow through the dewatering orifice cannot be utilized when calculating the 100-year storm elevation because of its potential to become clogged; therefore, available spillway storage must begin at the principal spillway riser crest. The principal spillway designed by the procedures contained in this standard will result in some reduction in the peak rate of runoff. However, the riser outlet design will not adequately control the basin discharge to the predevelopment discharge limitations as stated in Minimum Requirement #7: Flow Control. However, if the basin for a permanent stormwater detention pond is used for a temporary Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-105 sedimentation basin, the control structure for the permanent pond can be used to maintain predevelopment discharge limitations. The size of the basin, the expected life of the construction project, the anticipated downstream effects and the anticipated weather conditions during construction, should be considered to determine the need of additional discharge control. See Figure 4.2.21 for riser inflow curves. Key divider into slope to prevent flow around sides The pond length shall be 3 to 6 times the maximum pond width Emergency overflow spillway Pond length Riser pipe Inflow Silt fence or Discharge to stabilized equivalent divider conveyance, outlet, or level spreader Note: Pond may be formed by berm or by partial or complete excavation Figure 4.2.18 â€“ Sediment Pond Plan View Riser pipe (principal spillway) Crest of open at top with emergency spillway 6' min. Width trash rack per Fig 4.4.4E Embankment compacted 95% Dewatering device pervious materials such as (see riser detail) gravel or clean sand shall not be used Discharge to stabilized Wire-backed silt fence Dewatering Concrete base conveyance outlet or staked haybales wrapped orifice (see riser detail) with filter fabric, or level spreader equivalent divider Figure 4.2.19 â€“ Sediment Pond Cross Section Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-106 Polyethylene cap Provide adequate strapping Perforated polyethylene Corrugated drainage tubing, diameter metal riser min. 2" larger than dewatering orifice. 3.5" min. Tubing shall comply with ASTM F667 and Watertight Dewatering orifice, schedule, AASHTO M294 coupling Tack weld 40 steel stub min. Diameter as per calculations 6" min. 18" min. Alternatively, metal stakes Concrete base and wire may be used to prevent flotation 2X riser dia. Min. Figure 4.2.20 â€“ Sediment Pond Riser Detail Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-107 Figure 4.2.21 â€“ Riser Inflow Curves Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-108 Principal Spillway: Determine the required diameter for the principal spillway (riser pipe). The diameter shall be the minimum necessary to pass the siteâ€™s 15-minute, 10-year flowrate. If using the Western Washington Hydrology Model (WWHM), Version 2 or 3, design flow is the 10-year (1 hour) flow for the developed (unmitigated) site, multiplied by a factor of 1.6. Use Figure 4.2.21 to determine this diameter (h = 1-foot). Note: A permanent control structure may be used instead of a temporary riser. Emergency Overflow Spillway: Determine the required size and design of the emergency overflow spillway for the developed 100-year peak flow using the method contained in Volume III. Dewatering Orifice: Determine the size of the dewatering orifice(s) (minimum 1-inch diameter) using a modified version of the discharge equation for a vertical orifice and a basic equation for the area of a circular orifice. Determine the required area of the orifice with the following equation: A 2( h) 5.0 A = s o 6.0 x3600Tg 5.0 where Ao = orifice area (square feet) As = pond surface area (square feet) h = head of water above orifice (height of riser in feet) T = dewatering time (24 hours) g = acceleration of gravity (32.2 feet/second2) Convert the required surface area to the required diameter D of the orifice: A D=24x o =13.54x A o Ï€ The vertical, perforated tubing connected to the dewatering orifice must be at least 2 inches larger in diameter than the orifice to improve flow characteristics. The size and number of perforations in the tubing should be large enough so that the tubing does not restrict flow. The orifice should control the flow rate. â€¢ Additional Design Specifications The pond shall be divided into two roughly equal volume cells by a permeable divider that will reduce turbulence while allowing movement of water between cells. The divider shall be at least one- half the height of the riser and a minimum of one foot below the top of the riser. Wire-backed, 2- to 3-foot high, extra strength filter fabric supported by treated 4"x4"s can be used as a divider. Alternatively, staked straw bales wrapped with filter fabric (geotextile) may be used. If the pond is more than 6 feet deep, a different mechanism must be proposed. A riprap embankment is one acceptable method of Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-109 separation for deeper ponds. Other designs that satisfy the intent of this provision are allowed as long as the divider is permeable, structurally sound, and designed to prevent erosion under or around the barrier. To aid in determining sediment depth, one-foot intervals shall be prominently marked on the riser. If an embankment of more than 6 feet is proposed, the pond must comply with the criteria contained in Volume III regarding dam safety for detention BMPs. â€¢ The most common structural failure of sedimentation basins is caused by piping. Piping refers to two phenomena: (1) water seeping through fine-grained soil, eroding the soil grain by grain and forming pipes or tunnels; and, (2) water under pressure flowing upward through a granular soil with a head of sufficient magnitude to cause soil grains to lose contact and capability for support. The most critical construction sequences to prevent piping will be: 1. Tight connections between riser and barrel and other pipe connections. 2. Adequate anchoring of riser. 3. Proper soil compaction of the embankment and riser footing. 4. Proper construction of anti-seep devices. Maintenance â€¢ Sediment shall be removed from the pond when it reaches 1â€“foot in Standards depth. â€¢ Any damage to the pond embankments or slopes shall be repaired. BMP C250: Construction Stormwater Chemical Treatment Purpose This BMP applies when using stormwater chemicals in batch treatment or flow-through treatment. Turbidity is difficult to control once fine particles are suspended in stormwater runoff from a construction site. Sedimentation ponds are effective at removing larger particulate matter by gravity settling, but are ineffective at removing smaller particulates such as clay and fine silt. Traditional erosion and sediment control BMPs may not be adequate to ensure compliance with the water quality standards for turbidity in receiving water. Chemical treatment can reliably provide exceptional reductions of turbidity and associated pollutants. Chemical treatment may be required to meet turbidity stormwater discharge requirements, especially when construction is to proceed through the wet season. Conditions of Use Formal written approval from Ecology is required for the use of chemical treatment regardless of site size. The Local Permitting Authority may also Volume II â€“ Construction Stormwater Pollution Prevention - August 2012 4-110 Stormwater Pollution Prevention Plan Appendix C â€“ Alternative BMPs The following includes a list of possible alternative BMPs for each of the 12 elements not described in the main SWPPP text. This list can be referenced in the event a BMP for a specific element is not functioning as designed and an alternative BMP needs to be implemented. Element #2 â€“ Establish Construction Entrance BMP C106: Wheel Wash 23 Stormwater Pollution Prevention Plan Appendix D â€“ General Permit A Department of Ecology Stormwater General Permit will be applied for with this project. A copy of the permit shall be located onsite at all times. The contractor shall be responsible for our discharge water quality monitoring and reporting to Ecology. 25 Stormwater Pollution Prevention Plan Appendix E â€“ Site Inspection Forms (and Site Log) The results of each inspection shall be summarized in an inspection report or checklist that is entered into or attached to the site log book. It is suggested that the inspection report or checklist be included in this appendix to keep monitoring and inspection information in one document, but this is optional. However, it is mandatory that this SWPPP and the site inspection forms be kept onsite at all times during construction, and that inspections be performed and documented as outlined below. At a minimum, each inspection report or checklist shall include: a. Inspection date/times b. Weather information: general conditions during inspection, approximate amount of precipitation since the last inspection, and approximate amount of precipitation within the last 24 hours. c. A summary or list of all BMPs that have been implemented, including observations of all erosion/sediment control structures or practices. d. The following shall be noted: i. locations of BMPs inspected, ii. locations of BMPs that need maintenance, iii. the reason maintenance is needed, iv. locations of BMPs that failed to operate as designed or intended, and v. locations where additional or different BMPs are needed, and the reason(s) why e. A description of stormwater discharged from the site. The presence of suspended sediment, turbid water, discoloration, and/or oil sheen shall be noted, as applicable. f. A description of any water quality monitoring performed during inspection, and the results of that monitoring. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. h. A statement that, in the judgment of the person conducting the site inspection, the site is either in compliance or out of compliance 26 Stormwater Pollution Prevention Plan with the terms and conditions of the SWPPP and the NPDES permit. If the site inspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, as well as a schedule of implementation. i. Name, title, and signature of person conducting the site inspection; and the following statement: â€œI certify under penalty of law that this report is true, accurate, and complete, to the best of my knowledge and beliefâ€. When the site inspection indicates that the site is not in compliance with any terms and conditions of the NPDES permit, the Permittee shall take immediate action(s) to: stop, contain, and clean up the unauthorized discharges, or otherwise stop the noncompliance; correct the problem(s); implement appropriate Best Management Practices (BMPs), and/or conduct maintenance of existing BMPs; and achieve compliance with all applicable standards and permit conditions. In addition, if the noncompliance causes a threat to human health or the environment, the Permittee shall comply with the Noncompliance Notification requirements in Special Condition S5.F of the permit. 27 Stormwater Pollution Prevention Plan Site Inspection Form General Information Project Name: GAYTEWAY BUSINESS PARK Inspector Name: Title: CESCL # : Date: Time: Inspection Type: â–¡ After a rain event â–¡ Weekly â–¡ Turbidity/transparency benchmark exceedance â–¡ Other Weather Precipitation Since last inspection In last 24 hours Description of General Site Conditions: Inspection of BMPs Element 1: Mark Clearing Limits BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP Element 2: Establish Construction Access BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP 28 Stormwater Pollution Prevention Plan Element 3: Control Flow Rates BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP Element 4: Install Sediment Controls BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP 29 Stormwater Pollution Prevention Plan Element 5: Stabilize Soils BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP Element 6: Protect Slopes BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP 30 Stormwater Pollution Prevention Plan Element 7: Protect Drain Inlets BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP Element 8: Stabilize Channels and Outlets BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Location Inspected Functioning Problem/Corrective Action 31 Stormwater Pollution Prevention Plan Y N Y N NIP Element 9: Control Pollutants BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP Element 10: Control Dewatering BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP BMP: Inspected Functioning Location Problem/Corrective Action Y N Y N NIP 32 Stormwater Pollution Prevention Plan Stormwater Discharges From the Site Observed? Problem/Corrective Action Y N Location Turbidity Discoloration Sheen Location Turbidity Discoloration Sheen 33 Stormwater Pollution Prevention Plan Water Quality Monitoring Was any water quality monitoring conducted? â–¡ Yes â–¡ No If water quality monitoring was conducted, record results here: If water quality monitoring indicated turbidity 250 NTU or greater; or transparency 6 cm or less, was The City notified by phone within 24 hrs? â–¡ Yes â–¡ No If The City was notified, indicate the date, time, contact name and phone number below: Date: Time: Contact Name: Phone #: General Comments and Notes Include BMP repairs, maintenance, or installations made as a result of the inspection. Were Photos Taken? â–¡ Yes â–¡ No If photos taken, describe photos below: 34 Stormwater Pollution Prevention Plan Appendix F â€“ Engineering Calculations SEDIMENT POND DESIGN Project Name: GAYTEWAY BLDG B & C - SWPPP By: P.A.D. Project Number: 18005 Date: 4/8/2019 DRAINAGE CRITERIA: CITY OF PORT ORCHARD RAINFALL METHOD: Santa Barbara Unit Hydrograph (SBUH) METHOD OF ANALYSIS: Step 1) Tributary Area to TESC Pond Tributary area = 7.80 ac * for Bldg B & C work, excl. 67th r.o.w. Soil Type = A CN (gravel)= 79 H = Storage depth = 4.0 ft Z = Sideslope = 3 ft/ft Step 2) Provided Sediment Trap Surface Area Provided trap dimensions: width (ft) length (ft) bottom = 20 50 water surface = 44 74 top = 50 80 Pond to be constructed for use for both the Bldg B & C sitework construction. Pond located within Bldg B (Lot 2) proposed parcel. Step 3) Peform SBUH Calculations TESC pond to infiltrate TESC runoff. Infiltration Rate = 10.0 in/hr *Geotech recommended infiltration rate of 13.7 in/hr. Check for the 2-yr & 10-yr, 24hr storm event using the SBUH method Start of live storage: 100.0000 ft Peak Stg Time to Event Match Q (cfs) Peak Q (cfs) Vol (cf) Vol (acft) (ft) Empty 2 year 0 0.236 100.0976 99.66 0.0023 25.33 10 year 0 0.471 101.9956 2927.48 0.0672 25.83 Conclusion: Infiltration TESC pond will handle the 10-yr storm event with 2' storage depth. <ok> ** See attached calculations. 35 Stormwater Pollution Prevention Plan DRAINAGE BASIN HYDROGRAPH DATA * Calculations based upon Stormshed Hydrograph Method software. RAINFALL DATA Event Precip (in) 2 year 1.70 10 year 2.60 DRAINAGE BASIN LANDCOVER AND DISCHARGE DATA Record Id: ERO Design Method SBUH Rainfall type TYPE1A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area 7.80 ac DCIA 0.00 ac Pervious CN 79.00 DC CN 0.00 Pervious TC 10.00 min DC TC 5.00 min Pervious CN Calc Description SubArea Sub cn GRAVEL SITE 7.80 ac 79.00 Pervious Composited CN (AMC 2) 79.00 Pervious TC Calc Type Description Length Slope Coeff Misc TT Fixed DIRT SITE 10.00 min Pervious TC 10.00 min Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed PAVING 5.00 min Directly Connected TC 5.00min PREDEV Event Summary BasinID Event Peak Q (cfs) Peak T (hrs) Peak Vol (ac-cf) Area (ac) Method/Loss Raintype ERO 2 year 0.2506 8.17 0.2317 7.80 SBUH/SCS TYPE1A ERO 10 year 1.1712 8.00 0.5883 7.80 SBUH/SCS TYPE1A 36 Stormwater Pollution Prevention Plan ** INFILTRATION TESC POND SIZING CALCULATIONS INFILTRATION POND DISCHARGE DATA Record Id: INFILT Descrip: Prototype Structure Increment 0.10 ft Start El. 100.0000 ft Max El. 105.0000 ft Infiltration rate 10.0000 in/hr WP Multiplier 1.00 TESC POND STORAGE DATA Record Id: POND Descrip: Prototype Record Increment 0.10 ft Start El. 100.0000 ft Max El. 108.0000 ft Length 50.0000 ft Width 20.0000 ft Length ss1 3.00v:1h Length ss2 3.0000v:1h Width ss1 3.00v:1h Width ss2 3.0000v:1h ROUTING RESULTS Start of live storage: 100.0000 ft Event Match Q (cfs) Peak Q (cfs) Peak Stg (ft) Vol (cf) Vol (acft) Time to Empty 2 year 0.0000 0.2360 100.0976 99.66 0.0023 25.33 10 year 0.0000 0.4710 101.9956 2927.48 0.0672 25.83 CONCLUSION The 50â€™ x 20â€™ x 4â€™ deep infiltration TESC pond provides adequate infiltration and storage for up to a 10-year storm for the onsite 7.8 acre disturbance area. 37 June 12, 2019 Nova Heaton City of Arlington WA Development Services Manger Community and Economic Development Re: Binding Site Plan application Gayteway Business Park You asked that we address the subject of wetlands. I am not aware that a wetland exists on the subject property. In addition there does not appear to be any wetland areas in the vicinity, according to the Snohomish County PDS Map Portal, attached. Please let me know if any additional information is required. Respectfully, Daniel B. Taylor Ownership Representative Gayteway Business Park 6/12/2019 Legend Critical Area Site Plans Snohomish County Tax Parcels 1: 10,000 1,666.7 0 833.33 1,666.7 Feet All maps, data, and information set forth herein (â€œDataâ€), are for illustrative purposes only and are not to be considered an official citation to, or Notes representation of, the Snohomish County Code. Amendments and updates to the Data, together with other applicable County Code provisions, may apply which are not depicted herein. Snohomish County makes no representation or warranty concerning the content, accuracy, currency, completeness or quality of the Data contained herein and expressly disclaims any warranty of merchantability or fitness for any particular No wetlands onsite or in immediate vicinity purpose. All persons accessing or otherwise using this Data assume all responsibility for use thereof and agree to hold Snohomish County Projection: NAD_1983_StatePlane_Washington_North_FIPS_4601_Feet harmless from and against any damages, loss, claim or liability arising out of any error, defect or omission contained within said Data. Planning and Development Services, Snohomish County Washington State Law, Ch. 42.56 RCW, prohibits state and local agencies from providing access to lists of individuals intended for use for commercial purposes and, thus, no commercial use may be made of any Data comprising lists of individuals contained herein. NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA DATE REVISION REMOVABLE BOLLARD 5/29/20 REVISED STREET LIGHT, SCREEN WALL, ADD MONUMENT SIGNS NO ORMA F REUSE EX. BOLLARDS. MONUMENT SIGN VERIFY EX. BOLLARD IS IN ACCCEPTABLE CONDITION. NEW STREET NEW STREET NEW STREET NEW PEDESTRIAN ERRA LIGHT ON EX. POLE LIGHT ON EX. POLE NEW DRIVEWAY LIGHT ON EX. POLE LIGHT (STA 56+75) T DESIGN GROUP, INC. PER DTL. 3/C1.4 REMOVE EX. REMOVE EX. (BUILDING 'C' SET) TREE (TYP) TREE (TYP) 67TH AVENUE NE P(OH) PROJECT NO. DRAWN BY: P(OH) CHECKED BY: 370.54' P(OH) P(OH) SCREEN WALL (TYP) P(OH) RELOCATE EX. RELOCATE EX. BOLLARDS TO END NEW PEDESTRIAN NEW PEDESTRIAN BOLLARDS TO END BUILDING 'B' OF EACH DRIVEWAY. LIGHT NEW STREET LIGHT REMOVE EX. METER & LIGHT NEW STREET LIGHT REMOVE EX. METER & OF EACH DRIVEWAY. PER PLAN BY GATE VALVE. PATCH SHIFT SCREEN WALL TO (TYP) PATCH EX. ASPHALT (TYP) EX. ASPHALT TRAIL TO NEW FIRE HYDRANT NW TRAFFEX (TYP) EX. ASPHALT TRAIL BACK OF CURB DUE TO TRAIL (FULL WIDTH) SHIFT SCREEN WALL TO BE SAWCUT & PATCHED PATCH EX. ASPHALT (FULL WIDTH) STREET LIGHT LOCATION. BACK OF CURB TO ALLOW TRAIL (FULL WIDTH) GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC IN AREAS OF FOR SIGN VISIBILITY. BUILDING 'B' BREAK IN SCREEN WALL DETERIORATION (AS SHEET TITLE DETERMINED BY CITY) BUILDING 'C' TO FIT SIGN. 67TH AVE - REVISIONS C1.2ASHEET NO. NW 1/4 AND SW 1/4 OF SEC. 14, T31N, R5E, W.M., CITY OF ARLINGTON, SNOHOMISH COUNTY, WA DATE REVISION REMOVABLE BOLLARD 10 REVISED STREET LIGHT, SCREEN WALL, ADD MONUMENT SIGNS NO ORMA F REUSE EX. BOLLARDS. MONUMENT SIGN MONUMENT SIGN VERIFY EX. BOLLARD IS IN ACCCEPTABLE CONDITION. NEW STREET NEW STREET NEW STREET ERRA LIGHT ON EX. POLE LIGHT ON EX. POLE NEW DRIVEWAY LIGHT ON EX. POLE T DESIGN GROUP, INC. PER DTL. 3/C1.4 REMOVE EX. NEW PEDESTRIAN REMOVE EX. (BUILDING 'C' SET) TREE (TYP) LIGHT TREE (TYP) 67TH AVENUE NE PROJECT NO. DRAWN BY: CHECKED BY: 370.54' SCREEN WALL (TYP) RELOCATE EX. BUILDING 'C' BUILDING 'B' RELOCATE EX. BOLLARDS TO END NEW PEDESTRIAN NEW PEDESTRIAN BOLLARDS TO END BUILDING 'B' OF EACH DRIVEWAY. LIGHT NEW STREET LIGHT REMOVE EX. METER & LIGHT NEW STREET LIGHT REMOVE EX. METER & OF EACH DRIVEWAY. PER PLAN BY GATE VALVE. PATCH SHIFT SCREEN WALL TO (TYP) PATCH EX. ASPHALT BACK OF CURB TO ALLOW (TYP) EX. ASPHALT TRAIL TO NEW FIRE HYDRANT NW TRAFFEX (TYP) EX. ASPHALT TRAIL SHIFT SCREEN WALL TO TRAIL (FULL WIDTH) (FULL WIDTH) FOR SIGN VISIBILITY. BE SAWCUT & PATCHED PATCH EX. ASPHALT BACK OF CURB TO ALLOW BREAK IN SCREEN WALL GAYTEWAY BUSINESS PARK for Gayteway Business Park LLC IN AREAS OF TRAIL (FULL WIDTH) FOR SIGN VISIBILITY. TO FIT SIGN. BREAK IN SCREEN WALL DETERIORATION (AS SHEET TITLE DETERMINED BY CITY) TO FIT SIGN. 67TH AVE - REVISIONS C1.2ASHEET NO.