The URL can be used to link to this page

Home My WebLink About207th St NE_PWD535_2025 ! "#$%&'()$((*+,%&%(, -. /! "#$%&'()$((* -. /-0011 23%45(6+ -. /7879 7: &*(%(5(;,<=2> > 8/ 1/ $?&;@&A&B C/ D 2 E . B$?&;F?;,?'4%(;'?;(($?;'G;(% 9 HIJ K .L / G 3%4%6+ M 80 )+N M11L0 3 EO1 D3> 9 L1 P6+66)+Q6N -11R/0 "&$S(AT UU$(,,('&AN(,S$?V%?#;QW;($6&X( QW;($"4#;( Y#;?;' 6@6Q=6 +)=" Z[+ ^Q\6)2;U(5(A#V(U Q)\Q] _^&S&;%`&;U Z6[Q6"Z+)] 6Q2D +6[ "6=D=D 8/ 1 )#;%$&S%#$"$?X&$a)#;%&S%"4#;(UU$(,,)#;%$&S%#$aV(?S(;,( ?S(;,(T b+<) (;&;?(A?&;D 3 D> 22;U )#;,%$cS%?#;)#;%$&S%#$&B#$b;Uc,%$?(,++2)d 5(;c(6=<"P D M/1 /1 N&%( ;,V(S%?#;aV(N(,S$?V%?#;S4(UcA(UN&%()#XVA(%(UN&%(;,V(S%#$ %&%c, D G+=+ZP "c;S4A?,%W&,(X&?A(U%# DDgQ+=Q6)QZZ+)Q6 "6)e @$?,%?;]#,%($G+;U#fA?;( SA(&;#c%;#%&%'$&U(#$ Bc$?(UGPe;((U'$#c% !" #$ $" %%&'() *+,*+*+,,-.-.-.-. /0123456478 ) $ 9" :; ) <";$" ' "= = $) $ &>?' ? <@ : &>?' AB>)( *+ &>?' "!C :D <!! $ $$D" $"! E>%')?%( , &>?' <!! $ (%'%& *+ &>?' $ ! " " # # # " $%&$% ' ( )*+,*+)+- ! . # / 0 )*1*+)+ ! '(2 (*32 )-*+*+)4 # 2 5 32 *-*+)6 ! '(2 ( 7 32 )8**+)6 0 ""9 # :3:(3 )$*)4*+)6 . ( # ## / 0 )*+6*+), ; <=! > ! "# $ ! "# % & & & '() *! $"# % & & '() *! &"# % & & '() *! "# % & & '() *! "# + & ,-' $ . "# & & /0*! "# & & /0*! "# & & "# R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's CITY OF ARLINGTON INSTRUCTIONS FOR ENGINEER COST ESTIMATE & BOND QUANTITY WORKSHEET 1) Based on permit type requested (Grading, Site Civil Construction, etc.), complete the form as follows: - For Grading permits, complete the Erosion Control section - For Site Civil Construction permits, complete the Erosion Control and General sections 2) Complete the 'Quantity' columns for the appropriate section(s). If you are completing the 'General' section, you will be asked to identify those quantities and costs that apply to Existing Right-of-Way, Future Public Improvements and Private Improvements. 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 Public Works fees due at intake for Grading and Site Civil construction permits only. This does not include fees required by other departments. 5) Per Resolution #772, all cost data for the engineers cost estimate is from the RS Means (latest edition) adjusted for the Snohomish County area or from local sources if not included in the RS Means. 6) Signed Professional Engineer stamp is required on all engineer cost estimates. 7) If an item that is part of your project does not exist in the spreadsheet complete the Write-In-Items section with the item and associated cost BOND QUANTITY ESTIMATE & ENGINEERS COST ESTIMATE SUMMARY Prepared By Project Information Name: Brian r. Kalab, PE Project Name: Portage Creek - Phase - I Date: PE Registration No: 36499 Project No: Firm Name: Insight Engineering Project Address: XXX Firm Address: PO Box 1478 Arlington, WA 98223 Phone No. 425-303-9363 Grading Quantities: 100 Email Address: brian@insightengineering.net (Cut / Fill) 1,338/1,438 CONSTRUCTION BOND AMOUNT MAINTENANCE BOND BOND WORKSHEET PE STAMP & SIGNATURE (prior to permit issuance) (after final acceptance of construction) Site Restoration/TESC Total (A) $ 17,573.38 (A) $ 17,573.38 Existing Right-of-Way Improvements Total (B) $ 19,482.84 (B) $ 19,482.84 Future Public Improvements Total (C) $ - (C) $ - Private Improvements Total (D) $ 63,206.29 (D) $ 63,206.29 TOTAL SITE CIVIL CONSTRUCTION COST $ 100,262.51 Site Restoration TESC Bond (A) x 150% $ 26,360.07 Site Civil Construction Surety Bond (A) + (B) + $ 55,584.33 (C) x 150% Maintenance Bond (B) + (C) x 20% $ 3,896.57 City of Arlington - 2009 Engineer Cost Estimate and Bond Quantity Worksheet Updated 12/22/2025 City of Arlington Engineer's Cost Estimate (A) Unit Reference # Price Unit Quantity Cost TEMPORARY EROSION & SEDIMENT CONTROL Backfill & compaction-embankment $6.50 CY Check dams BMP C207 $78.00 Each Catch Basin Protection $35.50 Each 1 35.50 Crushed surfacing 1 1/4" minus WSDOT 9-03.9(3) $98.00 CY Ditching $8.00 CY Excavation-bulk $3.00 CY 500 1500.00 Fence, silt BMP C233 $2.00 LF 500 1000.00 Fence, Temporary (NGPA) $2.00 LF Geotextile Fabric $2.50 SY Hay Bale Silt Trap $0.50 Each Hydroseeding BMP C120 $1.00 SY Interceptor Swale / Dike $1.00 LF Jute Mesh BMP C122 $2.00 SY Level Spreader $1.75 LF Mulch, by hand, straw, 3" deep BMP C121 $3.00 SY 1000 3000.00 Mulch, by machine, straw, 2" deep BMP C121 $1.00 SY 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 BMP C123 $3.00 SY Rip Rap, machine placed; slopes WSDOT 9-13.1(2) $50.00 CY Rock Construction Entrance, 50'x15'x1' BMP C105 $1,800.00 Each Rock Construction Entrance, 100'x15'x1' BMP C105 $3,600.00 Each 1 3600.00 Sediment pond riser assembly BMP C241 $3,050.00 Each Sediment trap, 5' high berm BMP C240 $21.00 LF Sed. trap, 5' high, riprapped spillway berm section BMP C240 $79.00 LF Seeding, by hand BMP C120 $1.00 SY Sodding, 1" deep, level ground BMP C120 $8.00 SY 200 1600.00 Sodding, 1" deep, sloped ground BMP C120 $9.50 SY TESC Supervisor $84.00 HR 8 672.00 Water truck, dust control BMP C140 $130.00 HR 8 1040.00 WRITE-IN-ITEMS EROSION/SEDIMENT SUBTOTAL: $ 12,447.50 30% CONTINGENCY & MOBILIZATION: $ 3,734.25 SALES TAX @ 8.6% $ 1,391.63 EROSION/SEDIMENT TOTAL: $ 17,573.38 (A) City of Arlington - 2009 Engineer's Cost Estimate Bond Quantity Worksheet Page 1 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-Way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost GENERAL ITEMS Backfill & Compaction- embankment $ 8.00 CY Backfill & Compaction- trench $ 11.00 CY 80 880.00 Clear/Remove Brush, by hand (acre) $ 2,363.00 Acre Bollards - fixed $ 325.00 Each Bollards - removable $ 600.00 Each Clearing/Grubbing/Tree Removal $ 6,000.00 Acre 0.72 4,320.00 Excavation - bulk $ 2.50 CY 1000 2,500.00 Excavation - Trench $ 5.00 CY 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 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 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, rockery $ 13.00 SF SUBTOTAL 7,700.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 2 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost STREET IMPROVEMENT 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 Barricade, Type I $ 36.00 LF Barricade Type II $ 25.00 LF Barricade, Type III ( Permanent ) $ 55.00 LF Conduit, 2" $ 5.00 LF Curb & Gutter, rolled $ 20.00 LF Curb & Gutter, vertical $ 15.00 LF 30 450.00 Curb and Gutter, demolition and disposal $ 20.00 LF 60 1,200.00 Curb, extruded asphalt $ 5.00 LF Curb, extruded concrete $ 4.50 LF Guard Rail $ 30.00 LF Sawcut, asphalt, 3" depth $ 3.50 LF Sawcut, concrete, per 1" depth $ 3.00 LF Sealant, asphalt $ 2.00 LF Shoulder, gravel, 4" thick $ 11.00 SY Sidewalk, 4" thick $ 40.00 SY 30 1,200.00 Sidewalk, 4" thick, demolition and disposal $ 36.00 SY 30 1,080.00 Sidewalk, 6" thick $ 45.00 SY Sidewalk, 6" thick, demolition and disposal $ 45.00 SY Signs LS Sign, Handicap $ 100.00 Each Striping, per stall $ 7.50 Each Street Light System LS Traffic Signal LS Traffic Signal Modification LS Striping, thermoplastic, ( for crosswalk ) $ 3.50 SF Striping, 4" reflectorized line $ 0.40 LF SUBTOTAL 3,930.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 3 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost STREET SURFACING/PAVEMENT Asphalt Overlay, 1.5" AC $ 12.00 SY Asphalt Overlay, 2" AC $ 15.00 SY Asphalt Road 2", First 2500 SY $ 10.00 SY Asphalt Road 2", Qty. over 2500SY $ 9.00 SY Asphalt Road 3", First 2500 SY $ 15.00 SY 80 1,200.00 400 6,000.00 Asphalt Road 3", Qty. over 2500 SY $ 13.00 SY 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 80 600.00 400 3,000.00 Gravel Base Course 4" $ 15.00 SY Gravel Base Course 6" $ 22.50 SY 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 SUBTOTAL 1,800.00 9,000.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 4 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost DRAINAGE Access Road, Retention / Detention $ 26.00 SY * (CBs include frame and lid) Beehive $ 90.00 Each CB Type I $ 1,650.00 Each 1 1,650.00 CB Type IL $ 1,850.00 Each CB Type II, 48" diameter $ 2,550.00 Each for additional depth over 4' $ 650.00 FT CB Type II, 54" diameter $ 2,700.00 Each for additional depth over 4' $ 600.00 FT CB Type II, 60" diameter $ 2,900.00 Each for additional depth over 4' $ 750.00 FT CB Type II, 72" diameter $ 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 Cleanout, PVC, 8" $ 300.00 Each 6 1,800.00 Culvert, Box __ ft x __ ft LS Culvert, PVC, 4" $ 12.00 LF Culvert, PVC, 6" $ 17.00 LF 250 4,250.00 Culvert, PVC, 8" $ 19.00 LF Culvert, PVC, 12" $ 30.00 LF 80 2,400.00 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, Concrete, 8" 36.00 LF SUBTOTAL 10,100.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 5 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost DRAINAGE (CONTINUED) Culvert, Concrete, 12" $ 43.00 LF 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 Culvert, CPP, 12" $ 28.00 LF Culvert, CPP, 15" $ 34.00 LF Culvert, CPP, 18" $ 39.00 LF 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) - Infiltration trench $ 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 10 520.00 Tank End Reducer (36" diameter) $ 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 SUBTOTAL 520 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 6 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost WATER SYSTEM Blowoff $ 1,800.00 Each Connection to Existing Water Main $ 2,000.00 Each 6 12000 Ductile Iron Watermain, CL 52, 6 Inch Diameter $ 65.00 LF Ductile Iron Watermain, CL 52, 8 Inch Diameter $ 85.00 LF Ductile Iron Watermain, CL 52, 10 Inch Diameter $ 103.00 LF Ductile Iron Watermain, CL 52, 12 Inch Diameter $ 125.00 LF Gate Valve, 6 inch Diameter $ 250.00 Each Gate Valve, 8 Inch Diameter $ 380.00 Each Gate Valve, 10 Inch Diameter $ 425.00 Each Gate Valve, 12 Inch Diameter $ 500.00 Each Fire Hydrant Assembly, with Guard Posts $ 3,000.00 Each Fire Hydrant Assembly, without Guard Posts $ 2,500.00 Each Air-Vac, 8 Inch Diameter $ 6,000.00 Each Air-Vac,10 Inch Diameter $ 7,500.00 Each Air-Vac, 12 Inch Diameter $ 12,000.00 Each Pressure Reducing Valve Assembly, 8 In. Diam. $ 3,800.00 Each Pressure Reducing Valve Assembly, 10 In. Diam. $ 4,200.00 Each Pressure Reducing Valve Assembly, 12 In. Diam. $ 5,000.00 Each Valve Marker Post $ 350.00 Each SUBTOTAL 12000 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 7 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost SANITARY SEWER Clean Outs $ 500.00 Each 2 1000 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 Diameter $ 8.00 LF Side Sewer Pipe, PVC. 6 Inch Diameter $ 12.00 LF 210 2520 Sewer Pipe, PVC, 8 inch Diameter $ 33.00 LF Sewer Pipe, PVC, 12 Inch Diameter $ 41.00 LF Sewer Pipe, PVC, ____ Inch Diameter LF Lift Station (Entire System) LS Manhole, 48 Inch Diameter $ 3,000.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 54 Inch Diameter $ 3,500.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 60 Inch Diameter $ 3,700.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 72 Inch Diameter $ 4,000.00 Each for additional depth over 4 feet/per foot $ 625.00 FEET Manhole, 96 Inch Diameter $ 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 SUBTOTAL 3520 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 8 of 9 Updated 12/22/2025 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost PARKING LOT SURFACING 2" Asphalt & 4" CSTC $ 28.00 SY LANDSCAPING & VEGETATION Street Trees $ 500.00 Each 20 10000 Median Landscaping LS Right-of-Way Landscaping LS Wetland Landscaping LS WRITE-IN-ITEMS (Such as detention/water quality vaults.) SUBTOTAL 10,000.00 SUBTOTAL (SUM ALL PAGES): 13,800.00 44,770.00 30% CONTINGENCY & MOBILIZATION: 4,140.00 13,431.00 SALES TAX @ 8.6% 1,542.84 5,005.29 GRANDTOTAL: 19,482.84 63,206.29 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 9 of 9 Updated 12/22/2025 STORMWATER SITE PLAN For Portage Creek â€“ Phase-I Prepared for City of Arlington 238 N. Olympic Ave Arlington, WA 98223 360.403.3500 Project Site Location: XXX 207th Pl NE Arlington, WA 98223 Applicant: Contact: Portage Creek, LLC IECO 11926 127th Ave. NE P.O. Box 1478 Lake Stevens, WA 98258 Everett, WA 98206 425-303-9363 Tax Idâ€™s: 31051200301000 IECO Project: 15-0740 Certified Erosion and Sedimentation Control Lead: To be named by contractor Stormwater Site Plan Prepared By: Jacob D. Mealey, E.I.T. Stormwater Site Plan Preparation Date: February 1, 2016 Approximate Construction Date: June 1, 2016 P.O Box 1478 ï³ Everett, WA 98206 ï³ P: 425.303.9363 F: 425.303.9362 ï³ info@insightengineering.net TABLE OF CONTENTS 1.0 Executive Summary ................................................................................................................3 1.1 Minimum Requirements Summary ..............................................................................................7 2.0 Existing Conditions ................................................................................................................9 3.0 Offsite Analysis .....................................................................................................................11 3.1 Upstream Analysis .....................................................................................................................14 3.2 Downstream Analysis ................................................................................................................14 4.0 Developed Conditions ..........................................................................................................16 5.0 Site Hydraulic ........................................................................................................................16 5.1 Existing Basin Summary ............................................................................................................18 5.2 Developed Basin Summary ........................................................................................................18 6.0 Appendix ...............................................................................................................................20 Figures Figure 1 - Minimum Requirements Flow Chart .........................................................................3 Figure 2 - Vicinity Map .................................................................................................................6 Figure 3 - Soil Map ......................................................................................................................10 Figure 4 â€“ Downstream Analysis Map .......................................................................................15 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 1 - Acronyms and Abbreviations _________________________________________ BMP Best Management Practices DOE Department of Ecology EDDS Engineering Design and Development Standards ESC Erosion and Sediment Control IECO Insight Engineering Company MR Minimum Requirement SWPPP Stormwater Pollution Prevention Plan SWMMWW Stormwater Management Manual for Western Washington TESC Temporary Erosion and Sediment Control WWHM Western Washington Hydrology Model Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 2 - 1.0 Executive Summary The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. Please refer to the Vicinity Map attached later in the section. This report follows the requirements defined in the 2005 DOE and the City of Arlington Requirements. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. Please refer to the soils map and descriptions attached later in this report for more details. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. Per Figure 2.2, (flow chart for new development requirements) Volume I of DOEâ€™s Stormwater Management Manual, Minimum requirements #1 through 10 shall apply for this project. See the Minimum Requirements Summary included later in this report. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 3 - design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. The water quality requirement would be obtained through routing the proposed drainage system to existing biosawales. The upstream flows will continue to bypass site through the existing drainage system that drains into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 4 - Figure 1 - Minimum Requirements (MR's) for New Development Projects Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 5 - FIGURE 2. VICINITY MAP SITE TAKEN FROM THE BING MAPS Figure 2 -Vicinity Map Portage Creek Arlington, Washington SCALE: DATE 2/2/16 JOB #: 15-0740 P.O. Box 1478 Everett, WA 98206 NTS : 425-303-9363, 425-303-9362 f. BY FILE NAME: Info@insightengineering.net JDM : 15-0740 /doc/Stormwater Site Plan Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 6 - 1.1 Minimum Requirements Summary MR : Minimum Requirement SWPPP : Stormwater Pollution Prevention Plan MR #1 Stormwater Site Plan Narrative: The Stormwater Site Plan preparation follows the City of Arlingon requirements and in accordance with DOE's 2005 SWMMWW. Refer to the executive summary within Section 1.0. MR #2 SWPPP Narrative: Refer to Appendix â€“A for the proposed SWPPP for the project. MR #3 Water pollution source control for new development: No source control pollutants pertains to the proposed project. MR #4 Preservation of Natural Drainage Systems and outfalls: The pond outlet will continue to its natural drainage path. MR #5 Onsite Stormwater Management: The yard and roof drains will be connected towards an on-site drainage system system. MR #6 Runoff Treatment: The water quality requirement would be obtained through routing the proposed drainage system to existing biosawales. MR #7 Flow Control: The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 7 - completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. MR #8 Wetlands protection: There are no wetlands located within the site. MR #9 Basin/Watershed Planning: Water quality and detention will be provided by the existing bioswales and pond. The existing pond will be revised according to the additional anticipated runoff. MR #10 Operations and Maintenance: Refer to Appendix â€“ B for a complete Operations and Maintenance Manual. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 8 - 2.0 Existing Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. Please refer to the soils map and descriptions attached later in this report for more details. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 9 - FIGURE 3. SOIL MAP SITE SOILS LEGEND 39â€”Norma loam 48â€”Pastik silt loam, 8 to 25 percent slopes 83â€”Water Figure 3 - Soil Map Portage Creek Arlington, Washington SCALE: DATE: 2/2/16 JOB #: 15-0740 P.O. Box 1478 Everett, WA 98206 NONE 425-303-9363, 425-303-9362 f. FILE NAME: Info@insightengineering.net BY: JDM 15-0740 /doc/Stormwater Site Plan Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 10 - Snohomish County Area, Washington 39â€”Norma loam Map Unit Setting ï‚· National map unit symbol: 2hyx ï‚· Elevation: 0 to 1,000 feet ï‚· Mean annual precipitation: 35 to 60 inches ï‚· Mean annual air temperature: 48 to 52 degrees F ï‚· Frost-free period: 150 to 200 days ï‚· Farmland classification: Prime farmland if drained Map Unit Composition ï‚· Norma and similar soils: 85 percent ï‚· Minor components: 15 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Description of Norma Setting ï‚· Landform: Depressions, drainageways ï‚· Parent material: Alluvium Typical profile ï‚· H1 - 0 to 10 inches: ashy loam ï‚· H2 - 10 to 28 inches: sandy loam ï‚· H3 - 28 to 60 inches: sandy loam Properties and qualities ï‚· Slope: 0 to 3 percent ï‚· Depth to restrictive feature: More than 80 inches ï‚· Natural drainage class: Poorly drained ï‚· Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.57 to 1.98 in/hr) ï‚· Depth to water table: About 0 inches ï‚· Frequency of flooding: None ï‚· Frequency of ponding: Frequent ï‚· Available water storage in profile: Moderate (about 9.0 inches) Interpretive groups ï‚· Land capability classification (irrigated): None specified ï‚· Land capability classification (nonirrigated): 3w ï‚· Hydrologic Soil Group: B/D ï‚· Other vegetative classification: Seasonally Wet Soils (G002XN202WA) Minor Components Bellingham ï‚· Percent of map unit: 5 percent Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 11 - ï‚· Landform: Depressions Custer ï‚· Percent of map unit: 5 percent ï‚· Landform: Depressions Terric medisaprists ï‚· Percent of map unit: 3 percent ï‚· Landform: Depressions Alderwood ï‚· Percent of map unit: 2 percent Snohomish County Area, Washington 48â€”Pastik silt loam, 8 to 25 percent slopes Map Unit Setting ï‚· National map unit symbol: 2hz7 ï‚· Elevation: 200 to 800 feet ï‚· Mean annual precipitation: 45 to 70 inches ï‚· Mean annual air temperature: 45 to 46 degrees F ï‚· Frost-free period: 140 to 200 days ï‚· Farmland classification: Farmland of statewide importance Map Unit Composition ï‚· Pastik and similar soils: 100 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Description of Pastik Setting ï‚· Landform: Terraces ï‚· Parent material: Volcanic ash and lacustrine deposits Typical profile ï‚· H1 - 0 to 6 inches: ashy silt loam ï‚· H2 - 6 to 29 inches: ashy silt loam ï‚· H3 - 29 to 60 inches: silt loam Properties and qualities ï‚· Slope: 8 to 25 percent ï‚· Depth to restrictive feature: More than 80 inches ï‚· Natural drainage class: Moderately well drained ï‚· Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) ï‚· Depth to water table: About 18 to 30 inches ï‚· Frequency of flooding: None Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 12 - ï‚· Frequency of ponding: None ï‚· Available water storage in profile: Very high (about 14.3 inches) Interpretive groups ï‚· Land capability classification (irrigated): None specified ï‚· Land capability classification (nonirrigated): 4e ï‚· Hydrologic Soil Group: C ï‚· Other vegetative classification: Soils with Moderate Limitations (G002XN602WA) Snohomish County Area, Washington 83â€”Water Map Unit Composition ï‚· Water: 100 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 13 - 3.0 Offsite Analysis The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. No visible on-site drainage problems were observed at the time of field investigations. 3.1 Upstream Analysis The upstream flows will continue to bypass site through the existing drainage system that drains to into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. 3.2 Downstream Analysis The outlet for the proposed detention/retention pond will be connected to a dispersion trench to disperse the outlet flows to drain into to the existing adjacent onsite pond. The outlet from the existing onsite pond flows into a detention pond located on the neighboring property to the northwest. The outlet from that pond drains to the west and travels underneath S Stillaguamish Ave into Kruger Creek that flows east in an unrestricted manner for about 2,900 feet and flows into Portage Creek. Portage creek flows west in an unrestricted manner. This is where the 1-mile downstream analysis was completed. There do not appear to be any restrictions or erosion problems within 1 mile of the site. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 14 - FIGURE 4. DOWNSTREAM ANALYSIS MAP SITE Figure 4 - Downstream Analysis Map Portage Creek Arlington, Washington P.O. Box 1478 Everett, WA 98206 SCALE: DATE: 2/2/16 JOB #: 15-0740 425-303-9363, 425-303-9362 f. NONE Info@insightengineering.net FILE NAME: BY: JDM 15-0740 \docs\drainage report Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 15 - 4.0 Developed Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. Per Figure 2.2, (flow chart for new development requirements) Volume I of DOEâ€™s Stormwater Management Manual, Minimum requirements #1 through 10 shall apply for this project. See the Minimum Requirements Summary included later in this report. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. The Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 16 - water quality requirement would be obtained through routing the proposed drainage system to existing biosawales. The upstream flows will continue to bypass site through the existing drainage system that drains into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 17 - 5.0 Site Hydraulic Conditions Total area included in the analysis = 1.89 Acres From the Soil Conservation Service Map of Snohomish County, the majority of the site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. 5.1 Existing Basin Summary Clearing Area (All Phases) = 1.89 Acres Existing Pond = 1.51 Acres Upstream Road Easement = 1.37 Acres Upstream Parcel (31051200301500) = 2.81 Acres Upstream Parcel (31051200301400) = 6.96 Acres Total Existing Basin = 14.54 Acres Existing Impervious: Road = 0.81 Acres Sidewalk = 0.11 Acres Existing Pond = 1.51 Acres Total Site Impervious = 2.43 Acres Forested area = 12.11 Acres Refer to the Existing Basin Map and the following pages for more details. 5.2 Developed Basin Summary Total Developed Basin = 14.54 Acres Developed Impervious Areas: Site Impervious: Driveway = 0.17 Acres Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 18 - New Road = 0.22 Acres Roof = 0.56 Acres Existing Road = 0.81 Acres Existing Sidewalk = 0.11 Acres Existing Pond = 1.51 Acres Total Site Impervious = 3.38 Acres Developed Pervious Areas: Site Pervious: Pervious Area (Lawn) = 0.94 Acres Forested Area = 10.22 Acres Refer to the Developed Basin Map and the following pages for more details. Total Pond Volume required = 116,000 CF Total Pond Volume Provided = 116,000 CF Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 19 - WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: Portage Creek Ex pond Recalc Site Name: Portage Creek Site Address: XXX Arlington WA City : Arlington Report Date: 1/18/2016 Gage : Everett Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.20 Version : 2015/03/18 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE Name : Ex Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat 12.11 Pervious Total 12.11 Impervious Land Use Acres ROADS FLAT 0.81 SIDEWALKS FLAT 0.11 POND 1.51 Impervious Total 2.43 Basin Total 14.54 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : Dv Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 20 - Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat 10.22 C, Lawn, Flat .94 Pervious Total 11.16 Impervious Land Use Acres ROADS FLAT 1.03 ROOF TOPS FLAT 0.56 DRIVEWAYS FLAT 0.17 SIDEWALKS FLAT 0.11 POND 1.51 Impervious Total 3.38 Basin Total 14.54 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater Additional Pond StoragAdditional Pond Storag ___________________________________________________________________ Name : Additional Pond Storage Depth: 1.71 ft. Discharge Structure Riser Height: 1.71 ft. Riser Diameter: 29 in. Notch Type: Rectangular Notch Width: 2.400 ft. Notch Height: 0.500 ft. Element Flows To: Outlet 1 Outlet 2 ___________________________________________________________________ Irregular Pond Hydraulic Table Stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) Infilt(cfs) 138.00 1.723 0.000 0.000 0.000 138.02 1.719 0.032 0.000 0.000 138.04 1.715 0.065 0.000 0.000 138.06 1.712 0.097 0.000 0.000 138.08 1.708 0.130 0.000 0.000 138.10 1.704 0.162 0.000 0.000 138.11 1.700 0.195 0.000 0.000 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 21 - 138.13 1.697 0.227 0.000 0.000 138.15 1.693 0.259 0.000 0.000 138.17 1.689 0.291 0.000 0.000 138.19 1.686 0.323 0.000 0.000 138.21 1.682 0.355 0.000 0.000 138.23 1.678 0.387 0.000 0.000 138.25 1.674 0.419 0.000 0.000 138.27 1.671 0.451 0.000 0.000 138.29 1.667 0.482 0.000 0.000 138.30 1.663 0.514 0.000 0.000 138.32 1.660 0.545 0.000 0.000 138.34 1.656 0.577 0.000 0.000 138.36 1.652 0.608 0.000 0.000 138.38 1.649 0.640 0.000 0.000 138.40 1.645 0.671 0.000 0.000 138.42 1.641 0.702 0.000 0.000 138.44 1.638 0.733 0.000 0.000 138.46 1.634 0.764 0.000 0.000 138.48 1.630 0.795 0.000 0.000 138.49 1.627 0.826 0.000 0.000 138.51 1.623 0.857 0.000 0.000 138.53 1.619 0.888 0.000 0.000 138.55 1.616 0.918 0.000 0.000 138.57 1.612 0.949 0.000 0.000 138.59 1.608 0.980 0.000 0.000 138.61 1.605 1.010 0.000 0.000 138.63 1.601 1.041 0.000 0.000 138.65 1.597 1.071 0.000 0.000 138.67 1.594 1.101 0.000 0.000 138.68 1.590 1.131 0.000 0.000 138.70 1.586 1.162 0.000 0.000 138.72 1.583 1.192 0.000 0.000 138.74 1.579 1.222 0.000 0.000 138.76 1.575 1.252 0.000 0.000 138.78 1.572 1.281 0.000 0.000 138.80 1.568 1.311 0.000 0.000 138.82 1.565 1.341 0.000 0.000 138.84 1.561 1.371 0.000 0.000 138.86 1.557 1.400 0.000 0.000 138.87 1.554 1.430 0.000 0.000 138.89 1.550 1.459 0.000 0.000 138.91 1.547 1.489 0.000 0.000 138.93 1.543 1.518 0.000 0.000 138.95 1.539 1.547 0.000 0.000 138.97 1.536 1.576 0.000 0.000 138.99 1.532 1.606 0.000 0.000 139.01 1.529 1.635 0.000 0.000 139.03 1.525 1.664 0.000 0.000 139.05 1.521 1.692 0.000 0.000 139.06 1.518 1.721 0.000 0.000 139.08 1.514 1.750 0.000 0.000 139.10 1.511 1.779 0.000 0.000 139.12 1.507 1.807 0.000 0.000 139.14 1.504 1.836 0.000 0.000 139.16 1.500 1.865 0.000 0.000 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 22 - 139.18 1.496 1.893 0.000 0.000 139.20 1.493 1.921 0.000 0.000 139.22 1.489 1.950 0.003 0.000 139.24 1.486 1.978 0.031 0.000 139.25 1.482 2.006 0.073 0.000 139.27 1.479 2.034 0.126 0.000 139.29 1.475 2.062 0.187 0.000 139.31 1.472 2.090 0.256 0.000 139.33 1.468 2.118 0.332 0.000 139.35 1.465 2.146 0.414 0.000 139.37 1.461 2.174 0.501 0.000 139.39 1.458 2.201 0.595 0.000 139.41 1.454 2.229 0.693 0.000 139.43 1.451 2.257 0.796 0.000 139.44 1.447 2.284 0.904 0.000 139.46 1.444 2.312 1.017 0.000 139.48 1.440 2.339 1.133 0.000 139.50 1.437 2.366 1.254 0.000 139.52 1.433 2.393 1.379 0.000 139.54 1.430 2.421 1.508 0.000 139.56 1.426 2.448 1.640 0.000 139.58 1.423 2.475 1.776 0.000 139.60 1.419 2.502 1.916 0.000 139.62 1.416 2.529 2.059 0.000 139.63 1.412 2.555 2.206 0.000 139.65 1.409 2.582 2.356 0.000 139.67 1.405 2.609 2.509 0.000 139.69 1.402 2.636 2.666 0.000 139.71 1.398 2.662 2.825 0.000 ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration ___________________________________________________________________ Predeveloped Landuse Totals for POC #1 Total Pervious Area:12.11 Total Impervious Area:2.43 ___________________________________________________________________ Mitigated Landuse Totals for POC #1 Total Pervious Area:11.16 Total Impervious Area:3.38 ___________________________________________________________________ Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 1.516944 5 year 2.109568 10 year 2.552211 25 year 3.171481 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 23 - 50 year 3.678219 100 year 4.225488 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.713636 5 year 0.952544 10 year 1.128971 25 year 1.373552 50 year 1.572121 100 year 1.78528 ___________________________________________________________________ Stream Protection Duration Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 1.791 0.623 1950 1.902 0.743 1951 1.606 0.650 1952 1.380 0.622 1953 1.768 0.494 1954 3.288 0.686 1955 1.801 1.068 1956 1.033 0.768 1957 1.699 1.010 1958 3.325 1.077 1959 1.310 0.800 1960 1.498 0.827 1961 4.437 1.078 1962 1.488 0.743 1963 2.189 0.816 1964 1.102 0.754 1965 1.139 0.580 1966 1.142 0.472 1967 2.518 0.845 1968 1.487 1.043 1969 3.824 0.649 1970 1.118 0.569 1971 1.643 0.735 1972 1.944 1.022 1973 1.638 0.553 1974 2.016 0.654 1975 1.690 0.603 1976 1.064 0.656 1977 1.025 0.550 1978 1.031 0.573 1979 2.370 1.218 1980 1.248 0.689 1981 1.126 0.542 1982 1.069 0.902 1983 1.627 0.614 1984 1.355 0.710 1985 1.782 0.904 1986 2.541 1.579 1987 1.549 0.920 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 24 - 1988 1.370 0.602 1989 1.506 0.471 1990 1.143 0.663 1991 1.247 0.655 1992 1.420 0.617 1993 1.114 0.523 1994 1.093 0.554 1995 0.924 0.728 1996 1.758 1.131 1997 2.757 2.034 1998 1.727 0.623 1999 0.984 0.587 2000 2.687 0.514 2001 0.914 0.393 2002 0.886 0.656 2003 1.203 0.486 2004 2.273 0.857 2005 1.104 0.698 2006 2.184 1.126 2007 1.991 0.911 2008 1.625 1.656 2009 1.201 0.702 ___________________________________________________________________ Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 4.4371 2.0335 2 3.8236 1.6560 3 3.3248 1.5789 4 3.2878 1.2185 5 2.7574 1.1310 6 2.6870 1.1257 7 2.5405 1.0785 8 2.5183 1.0770 9 2.3695 1.0679 10 2.2726 1.0435 11 2.1886 1.0221 12 2.1838 1.0099 13 2.0164 0.9205 14 1.9908 0.9111 15 1.9445 0.9038 16 1.9016 0.9022 17 1.8011 0.8565 18 1.7907 0.8453 19 1.7818 0.8269 20 1.7679 0.8156 21 1.7581 0.7999 22 1.7269 0.7682 23 1.6989 0.7543 24 1.6903 0.7428 25 1.6426 0.7427 26 1.6378 0.7352 27 1.6273 0.7282 28 1.6247 0.7099 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 25 - 29 1.6058 0.7022 30 1.5487 0.6982 31 1.5058 0.6889 32 1.4978 0.6859 33 1.4879 0.6626 34 1.4873 0.6559 35 1.4203 0.6558 36 1.3804 0.6550 37 1.3696 0.6542 38 1.3547 0.6501 39 1.3096 0.6489 40 1.2480 0.6233 41 1.2473 0.6227 42 1.2028 0.6222 43 1.2007 0.6173 44 1.1435 0.6139 45 1.1415 0.6028 46 1.1389 0.6018 47 1.1256 0.5870 48 1.1175 0.5798 49 1.1141 0.5730 50 1.1037 0.5685 51 1.1019 0.5537 52 1.0928 0.5528 53 1.0695 0.5502 54 1.0641 0.5419 55 1.0328 0.5234 56 1.0313 0.5139 57 1.0253 0.4942 58 0.9836 0.4860 59 0.9244 0.4721 60 0.9137 0.4714 61 0.8864 0.3929 ___________________________________________________________________ Stream Protection Duration POC #1 The Facility PASSED The Facility PASSED. Flow(cfs) Predev Mit Percentage Pass/Fail 0.7585 1813 921 50 Pass 0.7880 1566 809 51 Pass 0.8175 1369 674 49 Pass 0.8469 1195 588 49 Pass 0.8764 1058 528 49 Pass 0.9059 955 475 49 Pass 0.9354 854 436 51 Pass 0.9649 763 403 52 Pass 0.9944 695 363 52 Pass 1.0239 634 320 50 Pass 1.0534 581 289 49 Pass 1.0829 540 259 47 Pass 1.1124 470 247 52 Pass Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 26 - 1.1419 420 231 55 Pass 1.1714 382 223 58 Pass 1.2009 353 208 58 Pass 1.2304 318 196 61 Pass 1.2598 281 191 67 Pass 1.2893 264 183 69 Pass 1.3188 238 169 71 Pass 1.3483 224 147 65 Pass 1.3778 204 130 63 Pass 1.4073 174 112 64 Pass 1.4368 159 97 61 Pass 1.4663 148 88 59 Pass 1.4958 132 78 59 Pass 1.5253 121 67 55 Pass 1.5548 106 57 53 Pass 1.5843 97 40 41 Pass 1.6138 88 32 36 Pass 1.6432 78 23 29 Pass 1.6727 73 17 23 Pass 1.7022 65 15 23 Pass 1.7317 60 10 16 Pass 1.7612 53 8 15 Pass 1.7907 49 6 12 Pass 1.8202 42 6 14 Pass 1.8497 37 5 13 Pass 1.8792 35 5 14 Pass 1.9087 33 5 15 Pass 1.9382 30 4 13 Pass 1.9677 29 3 10 Pass 1.9972 26 2 7 Pass 2.0266 24 1 4 Pass 2.0561 23 0 0 Pass 2.0856 23 0 0 Pass 2.1151 21 0 0 Pass 2.1446 20 0 0 Pass 2.1741 18 0 0 Pass 2.2036 15 0 0 Pass 2.2331 14 0 0 Pass 2.2626 14 0 0 Pass 2.2921 13 0 0 Pass 2.3216 12 0 0 Pass 2.3511 12 0 0 Pass 2.3806 10 0 0 Pass 2.4100 10 0 0 Pass 2.4395 10 0 0 Pass 2.4690 10 0 0 Pass 2.4985 10 0 0 Pass 2.5280 8 0 0 Pass 2.5575 7 0 0 Pass 2.5870 7 0 0 Pass 2.6165 7 0 0 Pass 2.6460 7 0 0 Pass 2.6755 7 0 0 Pass 2.7050 6 0 0 Pass 2.7345 6 0 0 Pass Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 27 - 2.7640 5 0 0 Pass 2.7934 5 0 0 Pass 2.8229 5 0 0 Pass 2.8524 5 0 0 Pass 2.8819 5 0 0 Pass 2.9114 5 0 0 Pass 2.9409 5 0 0 Pass 2.9704 5 0 0 Pass 2.9999 5 0 0 Pass 3.0294 5 0 0 Pass 3.0589 5 0 0 Pass 3.0884 5 0 0 Pass 3.1179 5 0 0 Pass 3.1474 5 0 0 Pass 3.1768 5 0 0 Pass 3.2063 5 0 0 Pass 3.2358 5 0 0 Pass 3.2653 5 0 0 Pass 3.2948 4 0 0 Pass 3.3243 4 0 0 Pass 3.3538 3 0 0 Pass 3.3833 3 0 0 Pass 3.4128 3 0 0 Pass 3.4423 3 0 0 Pass 3.4718 3 0 0 Pass 3.5013 3 0 0 Pass 3.5308 3 0 0 Pass 3.5602 3 0 0 Pass 3.5897 3 0 0 Pass 3.6192 3 0 0 Pass 3.6487 3 0 0 Pass 3.6782 3 0 0 Pass _____________________________________________________ ___________________________________________________________________ Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. ___________________________________________________________________ ___________________________________________________________________ LID Report LID Technique Used for Total Volumn Volumn Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volumn Volumn Volumn Water Quality Treatment Facility (ac-ft) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Additional Pond Storage POC N 1245.18 N Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 28 - 0.00 Total Volume Infiltrated 1245.18 0.00 0.00 0.00 0.00 0% No Treat. Credit Compliance with LID Standard 8 Duration Analysis Result = Passed ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ 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. 2005-2016; All Rights Reserved. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 29 - 6.0 Appendix A. Stormwater Pollution Prevention Plan B. Operations and Maintenance Manual C. Bond Quantities Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 30 - A. STORMWATER POLLUTION PREVENTION PLAN This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the Construction stormwater permit requirements for the Portage Creek - Phase-I project in Arlington, Washington. It is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. 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. This SWPPP was prepared based on the requirements set forth in the Construction Stormwater General Permit and in the Stormwater Management Manual for Western Washington (SWMMWW 2005). Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 31 - The 12 BMP Elements 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. 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. Install the temporary construction entrance, according to the approved construction plans, prior to any clearing or grading activities. Maintain until the access road is paved. 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. In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements. A sediment pond is proposed to control flow rates during grading activity. Element #4 â€“ Install Sediment Controls Install silt fencing, according to the approved plans, prior to any clearing or grading activities. Maintain until all construction activities are completed. Element #5 â€“ Stabilize Soils Exposed and un-worked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. Apply temporary hydro-seed to exposed and un-worked soils, according to the approved construction plans, as needed to prevent erosion during site grading. Apply permanent hydro-seed to areas at final grade as site grading is completed. Apply mulching to exposed and un-worked soils, according to the approved construction plans, as needed to prevent erosion during site grading. Maintain until site grading is completed and permanent hydro-seed is applied. Cover stockpiles with plastic sheeting, according to the approved construction plans, as needed to prevent erosion during site grading. Maintain until stockpiles are removed from site. Element #6 â€“ Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes erosion. The following specific BMPs will be used to protect slopes for this project. 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 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 32 - 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. 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. 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 housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. Element #10 â€“ Control Dewatering There will be no dewatering expected as part of this proposal. If it occurs, Baker tanks will be used for dewatering. Element #11 â€“ Maintain BMPs All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMPâ€™s specifications. Visual monitoring of the BMPs will be conducted at least once every calendar week and within 24 hours of any rainfall event that causes a discharge from the site. If the site becomes inactive, and is temporarily stabilized, the inspection frequency will be reduced to once every month. All temporary erosion and sediment control BMPs shall be removed within 30 days after the final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be removed or stabilized on site. Disturbed soil resulting from removal of BMPs or vegetation shall be permanently stabilized. Element #12 â€“ Manage the Project Erosion and sediment control BMPs for this project have been designed based on the following principles: Design the project to fit the existing topography, soils, and drainage patterns; 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 and Schedule major earthwork during the dry season. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven (7) days following the inspection. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 33 - B. OPERATION AND MAINTENANCE MANUAL The facilities that require periodic maintenance for this project are as follows. o Catch basins o Catch basin Inserts Refer to the following pages for facilities that require maintenance. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 34 - C. BOND QUANTITIES Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 35 - 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 3/2/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 1. MH Sht. C1-1 Provide Basin Area of south side of 207th St. that contributes an offsite run on for total pond capacity. 2. MH Sht. C 2.0 It appears that the grading will remove more than the recommended amount contained within the Geotechnical Report. 3. MH Sht. C 2.1 Identify where catch basin inserts are to be placed on the plan sheet. 4. MH Sht. C 2.1 The installation of pea gravel is critical in this installation of silt fence since there is no storage area for runoff. 5. MH Sht. C 3.0 How is water quality and flow control being addressed by this proposed system? 6. MH Sht. C 3.0 Why is the runoff not being directed to a level spreader before entering pond as originally discussed? 7. MH Sht. C 3.0 Where is the proposed weir design? 8. MH Sht. C 3.0 Delineate the Critical Area Buffer on this sheet. 9. MH General Upon review of the Geotechnical Report produced by Associated Earth Sciences, Inc. whereas it states, that per their recommendation, no homes should be built any further east than Geologic Cross â€“ Section C-Câ€™ because of the high risk of future impacts caused by landslide activity.. Please provide a sheet that also includes the proposed Phase II and Phase III along with Geologic Cross Sections A-Aâ€™, B-Bâ€™ and C-Câ€™ delineated upon it. 10. GS Sht. 4.0 Show water meters in proper location between curb and sidewalk per COA Standard W-070. 11. GS Sht. 4.0 Show water main in proper alignment with valving. 12. GS Sht. 4.0 Show water valves in proper configuration (West-East and South). 13. FR Sht. C 3.1 Elimination of two 6" sewer lines and replace with one 8" line is a cost savings and meets current standards for Page 1 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 3/2/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved construction. Standards paragraphs are cited in the redlines. See Attachment 1-A. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. Page 2 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 3/2/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. Page 3 of 3 Attachment A-1 REVIEW COMMENT SUMMARY AND RESOLUTION SHEET Submittal: Portage Creek - Phase I CODE A. Incorporated B. Open/Under Review Agency/Company/Reviewer C. Evaluated/Not Incorporated D. Beyond Scope/Not Evaluated Gina Franco E. Clarify or discuss Submittal Date: 2/1/2016 X. Comment closed Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) There is not a interceptor trench or rock check dams shown on the 1 G. Franco C2.1 drawings. These items are mentioned in the construction phasing note 4. No catch basin inserts are shown. Show where catch basin inserts will 2 G. Franco C2.1 be used. To improve clarity, suggest that existing grading no longer be shown, 3 G. Franco C2.1 only proposed grading. 4 G. Franco C2.1 Element #8 doesn't specify how the outfalls will be protected. Identify containment options and spill prevention measures for 5 G. Franco C2.1 Element #9. COA Public Works Standards and 6 G. Franco C3.0 Specifications, No pipe material, joints, or protective treatment specified for any pipe Section 3-3.01 shown. COA Public Works Standards and 7 G. Franco C3.0 Specifications, Specify type of catch basin per the standard specifications. Provide Section 3-4.01 catch basin detail or section view in a profile. COA Public Works Standards and 8 G. Franco C3.0 Specifications, Specify type of catch basin and yard drain or roof drain per the Section 3-4.02 standard specifications. COA Public Works Standards and 9 G. Franco C3.0 Specifications, Section 3-4.06 states debris barrier is required, comply with the Section 3-4.06 standard specifications. COA Public Works Standards and 10 G. Franco C3.0 Specifications, There is no culvert protection provided for the stormwater outfall on Section 3-6.03 and 3-the drawings or described in the storm drainage report. Comply with 7 Section 3-6.03. COA Public Works Standards and 11 G. Franco C3.0 Specifications, The weir and pond outlet that is described in the drainage report are Section 3-8.02 and 3-not shown on the drawings. Details should be provide to verify that the 8.08 weir and pond outlet comply with Section 3-8.03 and 3-8.08. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) COA Public Works Standards and 12 G. Franco C3.0 Specifications, The pond area is not clearly delineated on the drawings. The pond Section 3-8.03 shall comply with Section 3-8.03. COA Public Works Standards and 13 G. Franco C3.0 Specifications, Provide infiltration or provide an explanation and backup to why it is Section 3-9.01 not being used. COA Public Works Standards and 14 G. Franco C3.0 Specifications, Provide easements for downspout roof drain collection pipes per Section 3-12 Section 3-12. Stormwater Site COA, Stormwater 15 G. Franco Plan Drainage Report No conveyance calculations were provided. Section 3.1, 16 G. Franco Page 14 No bioswale is shown on the drawings. There is no design or details for the detention/retention pond, Section 3.2, COA, Stormwater 17 G. Franco dispersion trench, or outlet from the pond. There is no backup for the Page 14 Drainage Report downstream analysis. COA, Stormwater There is no mention of the mitigation measures for Critical Areas A 18 G. Franco Drainage Report and B. Minimum requirement (MR) #5 requires that on-site stormwater COA, Stormwater Section 1.1, management BMPs to infiltrate, disperse, and retain stormwater runoff 19 G. Franco Drainage Report, Page 7 onsite to the maximum extent feasible. Please address these Section 2.5.5 requirements. MR #6 requires that runoff treatment. See Volume V of the COA, Stormwater Section 1.1, SWMMWW (2005), BMP T9.10 states that bioswales are not suitable 20 G. Franco Drainage Report, Page 7 for water quality. There is design criteria to use if a bioswale is the Section 2.5.6 only option. Please address this requirement. Section 5, Page COA, Stormwater No infiltration is discussed whether applicable or not. No storm 21 G. Franco 16 Drainage Report conveyance is discussed or designed. Section 5, Page COA, Stormwater 22 G. Franco 18 Drainage Report Existing Basin Map was not provided. COA, Stormwater SWPPP, Page 23 G. Franco Drainage Report, How will the stormwater discharge be controlled? It should be 32 Section 2.5.2 specified in Element #3 of the SWPPP. COA, Stormwater Element #4 should reference catch basin inserts, mulch or SWPPP, Page 24 G. Franco Drainage Report, hydroseeding, and sediment pond that is intended to be used on site 32 Section 2.5.2 as shown on drawing C2.1. COA, Stormwater Add to Element #5 in the SWPPP or to the construction drawing C2.1: SWPPP, Page 25 G. Franco Drainage Report, Soil shall be stabilized at the end of the shift before a holiday or 32 Section 2.5.2 weekend if needed based on the weather forecast. COA, Stormwater SWPPP, Page 26 G. Franco Drainage Report, No specific BMPs are listed to protect slopes in Element #6. Provide 32 Section 2.5.2 BMPs as required by the City. COA, Stormwater SWPPP, Page 27 G. Franco Drainage Report, No specific BMPs are listed to protect inlets and culverts in Element 32 and 33 Section 2.5.2 #7. Provide BMPs and inspection requirements required by the City. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) COA, Stormwater SWPPP, Page 28 G. Franco Drainage Report, No specific BMPs are listed to stabilize channels and outlets in 33 Section 2.5.2 Element #8. Please provide BMPs as required by the City. COA, Stormwater SWPPP, Page 29 G. Franco Drainage Report, No specific BMPs are listed to control pollutants in Element #9. 33 Section 2.5.2 Provide BMPs as required by the City. The WWHM model was not checked at this time due to insufficient Section 5, Page COA, Stormwater information provided. Provide the basin map or plans for the site and 30 G. Franco 20, Hydrologic Drainage Report offsite areas which show the location of basins and sub-basins which Model correspond to the analysis for the site. To Marc Hayes, Permit Center Manager Page 1 CC Kristin Foster, Permit Technician Portage Creek â€“ Phase I Subject Initial Review of Stormwater Site Plan Report and Drainage Plans From Gina Franco, P.E., AECOM Date February 26, 2016 We have performed an initial review of the Portage Creek â€“ Phase I project. Our review included both the Stormwater Site Plan Report and applicable drainage sheets of the civil drawings (C2.1, C3.0, and C3.1) for compliance with the City of Arlington (COA) stormwater standards and the 2005 Washington State Department of Ecology Stormwater Management Manual for Western Washington (SWMMWW). This initial review has concluded that the Stormwater Site Plan Report and drainage sheets do not provide adequate information to demonstrate compliance with the required codes as listed previously. Review comments are provided on the attachment. Please provide a written response to the items attached with an indication as to the method of resolution and the location within the plans or storm drainage report. Due to the nature of the comments, further review will be necessary. Should you have any questions concerning the attached comments, please contact Gina Franco at (206) 438-2068 or gina.franco@aecom.com. Attachment 1: Stormwater Site Plan Report and Drainage Sheets Review Comments Portage Creek Development â€“ Phase I Review Page | 1 REVIEW COMMENT SUMMARY AND RESOLUTION SHEET Submittal: Portage Creek - Phase I CODE A. Incorporated B. Open/Under Review Agency/Company/Reviewer C. Evaluated/Not Incorporated D. Beyond Scope/Not Evaluated Gina Franco E. Clarify or discuss Submittal Date: 2/1/2016 X. Comment closed Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) There is not a interceptor trench or rock check dams shown on the 1 G. Franco C2.1 drawings. These items are mentioned in the construction phasing note 4. No catch basin inserts are shown. Show where catch basin inserts will 2 G. Franco C2.1 be used. To improve clarity, suggest that existing grading no longer be shown, 3 G. Franco C2.1 only proposed grading. 4 G. Franco C2.1 Element #8 doesn't specify how the outfalls will be protected. Identify containment options and spill prevention measures for 5 G. Franco C2.1 Element #9. COA Public Works Standards and 6 G. Franco C3.0 Specifications, No pipe material, joints, or protective treatment specified for any pipe Section 3-3.01 shown. COA Public Works Standards and 7 G. Franco C3.0 Specifications, Specify type of catch basin per the standard specifications. Provide Section 3-4.01 catch basin detail or section view in a profile. COA Public Works Standards and 8 G. Franco C3.0 Specifications, Specify type of catch basin and yard drain or roof drain per the Section 3-4.02 standard specifications. COA Public Works Standards and 9 G. Franco C3.0 Specifications, Section 3-4.06 states debris barrier is required, comply with the Section 3-4.06 standard specifications. COA Public Works Standards and 10 G. Franco C3.0 Specifications, There is no culvert protection provided for the stormwater outfall on Section 3-6.03 and 3-the drawings or described in the storm drainage report. Comply with 7 Section 3-6.03. COA Public Works Standards and 11 G. Franco C3.0 Specifications, The weir and pond outlet that is described in the drainage report are Section 3-8.02 and 3-not shown on the drawings. Details should be provide to verify that the 8.08 weir and pond outlet comply with Section 3-8.03 and 3-8.08. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) COA Public Works Standards and 12 G. Franco C3.0 Specifications, The pond area is not clearly delineated on the drawings. The pond Section 3-8.03 shall comply with Section 3-8.03. COA Public Works Standards and 13 G. Franco C3.0 Specifications, Provide infiltration or provide an explanation and backup to why it is Section 3-9.01 not being used. COA Public Works Standards and 14 G. Franco C3.0 Specifications, Provide easements for downspout roof drain collection pipes per Section 3-12 Section 3-12. Stormwater Site COA, Stormwater 15 G. Franco Plan Drainage Report No conveyance calculations were provided. Section 3.1, 16 G. Franco Page 14 No bioswale is shown on the drawings. There is no design or details for the detention/retention pond, Section 3.2, COA, Stormwater 17 G. Franco dispersion trench, or outlet from the pond. There is no backup for the Page 14 Drainage Report downstream analysis. COA, Stormwater There is no mention of the mitigation measures for Critical Areas A 18 G. Franco Drainage Report and B. Minimum requirement (MR) #5 requires that on-site stormwater COA, Stormwater Section 1.1, management BMPs to infiltrate, disperse, and retain stormwater runoff 19 G. Franco Drainage Report, Page 7 onsite to the maximum extent feasible. Please address these Section 2.5.5 requirements. MR #6 requires that runoff treatment. See Volume V of the COA, Stormwater Section 1.1, SWMMWW (2005), BMP T9.10 states that bioswales are not suitable 20 G. Franco Drainage Report, Page 7 for water quality. There is design criteria to use if a bioswale is the Section 2.5.6 only option. Please address this requirement. Section 5, Page COA, Stormwater No infiltration is discussed whether applicable or not. No storm 21 G. Franco 16 Drainage Report conveyance is discussed or designed. Section 5, Page COA, Stormwater 22 G. Franco 18 Drainage Report Existing Basin Map was not provided. COA, Stormwater SWPPP, Page 23 G. Franco Drainage Report, How will the stormwater discharge be controlled? It should be 32 Section 2.5.2 specified in Element #3 of the SWPPP. COA, Stormwater Element #4 should reference catch basin inserts, mulch or SWPPP, Page 24 G. Franco Drainage Report, hydroseeding, and sediment pond that is intended to be used on site 32 Section 2.5.2 as shown on drawing C2.1. COA, Stormwater Add to Element #5 in the SWPPP or to the construction drawing C2.1: SWPPP, Page 25 G. Franco Drainage Report, Soil shall be stabilized at the end of the shift before a holiday or 32 Section 2.5.2 weekend if needed based on the weather forecast. COA, Stormwater SWPPP, Page 26 G. Franco Drainage Report, No specific BMPs are listed to protect slopes in Element #6. Provide 32 Section 2.5.2 BMPs as required by the City. COA, Stormwater SWPPP, Page 27 G. Franco Drainage Report, No specific BMPs are listed to protect inlets and culverts in Element 32 and 33 Section 2.5.2 #7. Provide BMPs and inspection requirements required by the City. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) COA, Stormwater SWPPP, Page 28 G. Franco Drainage Report, No specific BMPs are listed to stabilize channels and outlets in 33 Section 2.5.2 Element #8. Please provide BMPs as required by the City. COA, Stormwater SWPPP, Page 29 G. Franco Drainage Report, No specific BMPs are listed to control pollutants in Element #9. 33 Section 2.5.2 Provide BMPs as required by the City. The WWHM model was not checked at this time due to insufficient Section 5, Page COA, Stormwater information provided. Provide the basin map or plans for the site and 30 G. Franco 20, Hydrologic Drainage Report offsite areas which show the location of basins and sub-basins which Model correspond to the analysis for the site. Section 5, Page Demonstrate adequate detention and water quality storage for this COA, Stormwater 31 G. Franco 20, Hydrologic project and provide documentation and model output for existing pond Drainage Report Model to show it is suitable and allowable for use by this project. Appendix B, SWMMWW Volume Operation and maintenance (O&M) manual is incomplete. Provide 32 G. Franco Page 34 I, Section 3.1.7 O&M Manual as required by the SWMMWW (2005). City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-Way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost GENERAL ITEMS Backfill & Compaction- embankment $ 8.00 CY Backfill & Compaction- trench $ 11.00 CY 80 880.00 Clear/Remove Brush, by hand (acre) $ 2,363.00 Acre Bollards - fixed $ 325.00 Each Bollards - removable $ 600.00 Each Clearing/Grubbing/Tree Removal $ 6,000.00 Acre 0.72 4,320.00 Excavation - bulk $ 2.50 CY 1000 2,500.00 Excavation - Trench $ 5.00 CY 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 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 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, rockery $ 13.00 SF SUBTOTAL 7,700.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 2 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost STREET IMPROVEMENT 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 Barricade, Type I $ 36.00 LF Barricade Type II $ 25.00 LF Barricade, Type III ( Permanent ) $ 55.00 LF Conduit, 2" $ 5.00 LF Curb & Gutter, rolled $ 20.00 LF Curb & Gutter, vertical $ 15.00 LF 30 450.00 Curb and Gutter, demolition and disposal $ 20.00 LF 60 1,200.00 Curb, extruded asphalt $ 5.00 LF Curb, extruded concrete $ 4.50 LF Guard Rail $ 30.00 LF Sawcut, asphalt, 3" depth $ 3.50 LF Sawcut, concrete, per 1" depth $ 3.00 LF Sealant, asphalt $ 2.00 LF Shoulder, gravel, 4" thick $ 11.00 SY Sidewalk, 4" thick $ 40.00 SY 30 1,200.00 Sidewalk, 4" thick, demolition and disposal $ 36.00 SY 30 1,080.00 Sidewalk, 6" thick $ 45.00 SY Sidewalk, 6" thick, demolition and disposal $ 45.00 SY Signs LS Sign, Handicap $ 100.00 Each Striping, per stall $ 7.50 Each Street Light System LS Traffic Signal LS Traffic Signal Modification LS Striping, thermoplastic, ( for crosswalk ) $ 3.50 SF Striping, 4" reflectorized line $ 0.40 LF SUBTOTAL 3,930.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 3 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost STREET SURFACING/PAVEMENT Asphalt Overlay, 1.5" AC $ 12.00 SY Asphalt Overlay, 2" AC $ 15.00 SY Asphalt Road 2", First 2500 SY $ 10.00 SY Asphalt Road 2", Qty. over 2500SY $ 9.00 SY Asphalt Road 3", First 2500 SY $ 15.00 SY 80 1,200.00 400 6,000.00 Asphalt Road 3", Qty. over 2500 SY $ 13.00 SY 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 80 600.00 400 3,000.00 Gravel Base Course 4" $ 15.00 SY Gravel Base Course 6" $ 22.50 SY 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 SUBTOTAL 1,800.00 9,000.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 4 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost DRAINAGE Access Road, Retention / Detention $ 26.00 SY * (CBs include frame and lid) Beehive $ 90.00 Each CB Type I $ 1,650.00 Each 1 1,650.00 CB Type IL $ 1,850.00 Each CB Type II, 48" diameter $ 2,550.00 Each for additional depth over 4' $ 650.00 FT CB Type II, 54" diameter $ 2,700.00 Each for additional depth over 4' $ 600.00 FT CB Type II, 60" diameter $ 2,900.00 Each for additional depth over 4' $ 750.00 FT CB Type II, 72" diameter $ 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 Cleanout, PVC, 8" $ 300.00 Each 6 1,800.00 Culvert, Box __ ft x __ ft LS Culvert, PVC, 4" $ 12.00 LF Culvert, PVC, 6" $ 17.00 LF 250 4,250.00 Culvert, PVC, 8" $ 19.00 LF Culvert, PVC, 12" $ 30.00 LF 80 2,400.00 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, Concrete, 8" 36.00 LF SUBTOTAL 10,100.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 5 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost DRAINAGE (CONTINUED) Culvert, Concrete, 12" $ 43.00 LF 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 Culvert, CPP, 12" $ 28.00 LF Culvert, CPP, 15" $ 34.00 LF Culvert, CPP, 18" $ 39.00 LF 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) - Infiltration trench $ 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 10 520.00 Tank End Reducer (36" diameter) $ 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 SUBTOTAL 520 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 6 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost WATER SYSTEM Blowoff $ 1,800.00 Each Connection to Existing Water Main $ 2,000.00 Each 6 12000 Ductile Iron Watermain, CL 52, 6 Inch Diameter $ 65.00 LF Ductile Iron Watermain, CL 52, 8 Inch Diameter $ 85.00 LF Ductile Iron Watermain, CL 52, 10 Inch Diameter $ 103.00 LF Ductile Iron Watermain, CL 52, 12 Inch Diameter $ 125.00 LF Gate Valve, 6 inch Diameter $ 250.00 Each Gate Valve, 8 Inch Diameter $ 380.00 Each Gate Valve, 10 Inch Diameter $ 425.00 Each Gate Valve, 12 Inch Diameter $ 500.00 Each Fire Hydrant Assembly, with Guard Posts $ 3,000.00 Each Fire Hydrant Assembly, without Guard Posts $ 2,500.00 Each Air-Vac, 8 Inch Diameter $ 6,000.00 Each Air-Vac,10 Inch Diameter $ 7,500.00 Each Air-Vac, 12 Inch Diameter $ 12,000.00 Each Pressure Reducing Valve Assembly, 8 In. Diam. $ 3,800.00 Each Pressure Reducing Valve Assembly, 10 In. Diam. $ 4,200.00 Each Pressure Reducing Valve Assembly, 12 In. Diam. $ 5,000.00 Each Valve Marker Post $ 350.00 Each SUBTOTAL 12000 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 7 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost SANITARY SEWER Clean Outs $ 500.00 Each 2 1000 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 Diameter $ 8.00 LF Side Sewer Pipe, PVC. 6 Inch Diameter $ 12.00 LF 210 2520 Sewer Pipe, PVC, 8 inch Diameter $ 33.00 LF Sewer Pipe, PVC, 12 Inch Diameter $ 41.00 LF Sewer Pipe, PVC, ____ Inch Diameter LF Lift Station (Entire System) LS Manhole, 48 Inch Diameter $ 3,000.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 54 Inch Diameter $ 3,500.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 60 Inch Diameter $ 3,700.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 72 Inch Diameter $ 4,000.00 Each for additional depth over 4 feet/per foot $ 625.00 FEET Manhole, 96 Inch Diameter $ 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 SUBTOTAL 3520 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 8 of 9 Updated 4/11/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost PARKING LOT SURFACING 2" Asphalt & 4" CSTC $ 28.00 SY LANDSCAPING & VEGETATION Street Trees $ 500.00 Each 20 10000 Median Landscaping LS Right-of-Way Landscaping LS Wetland Landscaping LS WRITE-IN-ITEMS (Such as detention/water quality vaults.) SUBTOTAL 10,000.00 SUBTOTAL (SUM ALL PAGES): 13,800.00 44,770.00 30% CONTINGENCY & MOBILIZATION: 4,140.00 13,431.00 SALES TAX @ 8.6% 1,542.84 5,005.29 GRANDTOTAL: 19,482.84 63,206.29 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 9 of 9 Updated 4/11/2016 Spill Prevention, Control and Countermeasures Plan Portage Creek â€“ Phase 1 Prepared by Insight Engineering Co. P.O. Box 1478 Everett, WA 98206 425-303-9363 April 1, 2016 THE CONTRACTOR SHALL MAINTAIN A COMPLETE, UPDATED COPY OF THIS PLAN IN AN ACCESSIBLE LOCATION ON THE PROJECT SITE AT ALL TIMES. SPCC Plan, Portage Creek 4/1/16 Page i Table of Contents SPCC Plan Implementation Requirements ..................................................................... 1 SPCC Plan Elements ...................................................................................................... 2 1. Responsible Personnel ........................................................................................... 2 2. Spill Reporting ........................................................................................................ 3 3. Project and Site Information ................................................................................... 4 4. Potential Spill Sources ............................................................................................ 5 5. Pre-Existing Contamination .................................................................................... 7 6. Spill Prevention and Response Training ................................................................. 8 7. Spill Prevention ....................................................................................................... 9 8. Spill Response ...................................................................................................... 12 9. Project Site Map ................................................................................................... 14 10. Spill Report Form(s) ............................................................................................ 15 11. Plan Approval ..................................................................................................... 16 SPCC Plan Acknowledgement Form (to be signed by all Project personnel) ................ 17 Appendix APPENDIX A EXAMPLE SPILL REPORT FORM ...................................................... A-18 SPCC Plan, Portage Creek 4/1/16 Page ii SPCC Plan Implementation Requirements WSDOT Standard Specification 1-07.15(1) and Project-specific special provisions (if applicable) require a Spill Prevention, Control and Countermeasures Plan (SPCC Plan or Plan) to be developed for each project. The purpose of an SPCC Plan is to protect human health and the environment from spills and releases of â€œhazardous materials,â€ a generic term to mean any material, including any substance, waste, or combination thereof, which because of its quantity, concentration, or physical, chemical, or infectious characteristics may cause, or significantly contribute to, a substantial present or potential hazard to human health, safety, property, or the environment when improperly treated, stored, transported, disposed of, or otherwise managed . The Engineer for Portage Creek â€“ Phase-I, has developed this SPCC Plan to satisfy WSDOT Standard Specification 1-07.15(1), and National Pollutant Discharge Elimination System (NPDES) requirements for the Project. The contractor shall update this SPCC Plan throughout the Project so that the written Plan reflects actual site conditions and practices. At a minimum, the contractor will update this Plan annually. The contractor shall fully implement this SPCC Plan, as accepted and updated, at all times. No on-site Project construction activities may commence until City of Arlington reviews and accepts this Project-Specific SPCC Plan. SPCC Plan, Portage Creek 4/1/16 Page 1 SPCC Plan Elements 1. Responsible Personnel Table 1.1 identifies the name(s), title(s), and contact information for the personnel responsible for implementing and updating the SPCC Plan, and for responding to spills. If spill response Subcontractor(s) will be used for spill response (as described in Section 8, Spill Response, below), the Subcontractor(s) company name(s) and contact information are also included in Table 1.1. Table 1 Responsible Personnel Responsibility Name and Title Contact Information Implementing and Updating Randy Brockway - Applicant Company: Portage Creek, LLC SPCC Plan (primary Office Phone: contact person) Cell Phone:(206)992-5051 Implementing and Updating Contractor (TBD) Company: SPCC Plan (secondary Office Phone: contact person) Cell Phone: On-Site Spill Responder Rick Crosby - Applicant Company: Carefree Homes Office Phone: Cell Phone: On-Site Spill Responder Contractor (TBD) Company: Office Phone: Cell Phone: SPCC Plan, Portage Creek 4/1/16 Page 2 2. Spill Reporting In the event of a spill, Contractor (TBD) shall notify the City of Arlington Surface Water Utility and shall notify the Federal, State, and Local Agencies listed in Table 2. Table 2 Project-Specific Federal, State, and Local Agencies to be Notified in the Event of a Spill Type of Discharge Who to Notify Time to Notify A spill or discharge, which could Ecology Regional Office: Immediately, but no later than 24- constitute a threat to human health, Northwest Region: hours after obtaining the welfare or the environment. 1-425-649-7000 knowledge. Lynnwood Police and/or Fire: 911 A spill or discharge of oil or National Response Center: Immediately hazardous substances which 1-800-424-8802 presents a threat to human or health, AND welfare, or the environment. Washington Emergency Management Division: 1-800-258-5990 OR 1-800-OILS911 AND Ecology Regional Office: Northwest Region: 1-425-649-7000 AND Lynnwood Police and/or Fire: 911 A spill or discharge which might WA State Department of Immediately cause bacterial contamination of Health: shellfish. 1-360-236-3330 AND Ecology Regional Office: Northwest Region: 1-425-649-7000 All Spills City of Lynnwood Surface Water Immediately Hotline: 425-670-KRUD (5783) SPCC Plan, Portage Creek 4/1/16 Page 3 3. Project and Site Information A. The Project work: The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. B. The site location and boundaries: The project is located at XXX 207th Pl NE Arlington, Washington. The boundaries for the project is the designated clearing limit. C. The drainage pathways from the site: See table 3 below. D. Nearby waterways and sensitive areas and their distances from the site: See table 3 below. Table 3 Nearby Waterways1 and Sensitive Areas2 Waterway1 or Distance from Direction of Flow Runoff Drainage Pathway Sensitive Area2 Project Site from Project Site from Site Kruger Creek 700 feet Downhill towards the Through the drainage system and northwest of northwest vegetation to the northeast to Project Site reach Scriber Creek Notes: 1 Waterways include streams, creeks, sloughs, rivers, Puget Sound, etc. 2 Sensitive areas are areas that typically contain populations that could be particularly sensitive to a hazardous materials spill or release. Such areas include wetlands, areas that provide habitat for threatened or endangered species, nursing homes, hospitals, child care centers, etc. Sensitive areas also include areas where groundwater is used for drinking water, such as wellhead protection zones and sole source aquifer recharge areas. SPCC Plan, Clare PUD 7/8/14 Page 4 4. Potential Spill Sources It is anticipated that diesel fuel and gasoline will be stored onsite during construction. No more than 20 gallons of each shall be onsite at any one time. Form oil and bond breaker for concrete forming will be used for the proposed project. No more than 10 gallons shall be onsite at any one time. All hazardous liquids shall be stored under a covered area near 207th Pl NE of the site and shall be located on spill containment pallets (or approved equal). SPCC Plan, Clare PUD 7/8/14 Page 5 Table 4 Fuel, Petroleum Product and other Hazardous Materials Brought or Generated On-Site Distance of Material Material Staging, Use, and Storage Est. Max. Amount of , Staging, Use, and Storage Location(s) & Material Storage and Hazardous Material Name Intended Use of Material Material On-Site at Locations from Nearby Secondary Containment Practices 2 Any One Time 1 Waterways and Sensitive and Structures 3 Areas Diesel Fuel Refueling 20 gal Covered area on spill containment 700 ft pallets near 207th Pl NE Gasoline Refueling 20 gal Covered area on spill containment 700 ft pallets near 207th Pl NE Form oil Concrete forming 10 gal Covered area on spill containment 700 ft pallets near 207th Pl NE Bond breaker Concrete forming 10 gal Covered area on spill containment 700 ft pallets near 207th Pl NE Notes: 1 See also Section 7.D (Spill Prevention, secondary containment and structures may be described in Table 4 or under Section 7D. 2 Waterways include streams, creeks, sloughs, rivers, Puget Sound, etc. 3 Sensitive areas are areas that typically contain populations that could be particularly sensitive to a hazardous materials spill or release. Such areas include wetlands, areas that provide habitat for threatened or endangered species, nursing homes, hospitals, child care centers, etc. Sensitive areas also include areas where groundwater is used for drinking water, such as wellhead protection zones and sole source aquifer recharge areas. SPCC Plan, Clare PUD 7/8/14 Page 6 5. Pre-Existing Contamination There are no known pre-existing contaminates on site. SPCC Plan, Clare PUD 7/8/14 Page 7 6. Spill Prevention and Response Training Train key personnel in the implementation of the Emergency SCP. Prepare a summary of the plan and post it at appropriate points in the building, identifying the spill cleanup coordinators, location of cleanup kits, and phone numbers of regulatory agencies to be contacted in the event of a spill. SPCC Plan, Clare PUD 7/8/14 Page 8 7. Spill Prevention A. Spill response kit contents and location(s) (see Table 7). Appropriately stocked spill response kits shall be maintained in close proximity to hazardous materials and equipment and shall be immediately accessible to all Project personnel. Table 7 Spill Response Kit Contents and Locations Type of Spill Kit Spill Kit Contents Spill Kit Location(s) Vehicle kit, drum Air horn to get attention of those working Covered area kit, conex kit nearby, personal protective equipment (PPE, such as safety glasses, gloves, coveralls, boot covers), spill pads, absorbent, booms, catch basin covers, anti-static shovels, garbage bags, plastic sheeting, overpack or disposal drum, complete copy of SPCC Plan, etc. B. Security measures for potential spill sources. The staging area will be surrounded by a secured fence, hazardous materials will be stored inside a locked storage shed, equipment will be equipped with locked fuel caps. C. Methods used to prevent stormwater from contacting fuel, petroleum products and hazardous materials. Contaminated soil will be placed on bermed plastic and covered. D. Secondary containment for each potential spill source listed in Section 4, above. Secondary containment structures shall be provided for all hazardous materials and capable of containing 110% of the volume contained in the largest tank within the containment structure. Double walled tank do not require additional secondary containment. E. Best Management Practices (BMP) Methods used to prevent discharges to ground or water during mixing and transfers of hazardous materials, petroleum product and fuel. Bmpâ€™s for Landscaping and Lawn/Vegetation Management: ï‚· Install engineered soil/landscape systems to improve the infiltration and regulation of stormwater in landscaped areas. ï‚· Do not dispose of collected vegetation into waterways or storm drainage systems. Bmpâ€™s for Loading and Unloading Areas for Liquid or Solid Material: ï‚· Sweep uncovered loading and unloading areas frequently to remove material that could otherwise be washed off by stormwater. Sweep outside areas that are covered for a period of time by containers, logs or other material after the areas are cleared. ï‚· Place drip pans, or other appropriate temporary containment device, at locations where leaks or spills may occur such as hose connections, SPCC Plan, Clare PUD 7/8/14 Page 9 hose reels and filler nozzles. Drip pans shall always be used when making and breaking connections (see Figure 2.2). Check loading/ unloading equipment such as valves, pumps, flanges, and connections regularly for leaks and repair as needed. BMPs for Spills of Oil and Hazardous Substances: ï‚· Train key personnel in the implementation of the Emergency SCP. Prepare a summary of the plan and post it at appropriate points in the building, identifying the spill cleanup coordinators, location of cleanup kits, and phone numbers of regulatory agencies to be contacted in the event of a spill; ï‚· Update the SCP regularly; ï‚· Immediately notify Ecology and the local Sewer Authority if a spill may reach sanitary or storm sewers, ground water, or surface water, in accordance with federal and Ecology spill reporting requirements; ï‚· Immediately clean up spills. Do not use emulsifiers for cleanup unless an appropriate disposal method for the resulting oily wastewater is implemented. Absorbent material shall not be washed down a floor drain or storm sewer; and, ï‚· Locate emergency spill containment and cleanup kit(s) in high potential spill areas. The contents of the kit shall be appropriate for the type and quantities of chemical liquids stored at the facility. BMPs for Storage of Liquid, Food Waste, or Dangerous Waste Containers: ï‚· Place tight-fitting lids on all containers. ï‚· Place drip pans beneath all mounted container taps and at all potential drip and spill locations during filling and unloading of containers. ï‚· Inspect container storage areas regularly for corrosion, structural failure, spills, leaks, overfills, and failure of piping systems. Check containers daily for leaks/spills. Replace containers, and replace and tighten bungs in drums as needed. ï‚· Businesses accumulating Dangerous Wastes that do not contain free liquids need only to store these wastes in a sloped designated area with the containers elevated or otherwise protected from storm water run-on. ï‚· Drums stored in an area where unauthorized persons may gain access must be secured in a manner that prevents accidental spillage, pilferage, or any unauthorized use. ï‚· If the material is a Dangerous Waste, the business owner must comply with any additional Ecology requirements as specified in Appendix IV-D R.3. ï‚· Storage of reactive, ignitable, or flammable liquids must comply with the Uniform Fire Code (Appendix IV-D R.2). ï‚· Cover dumpsters, or keep them under cover such as a lean-to, to prevent the entry of stormwater. Replace or repair leaking garbage dumpsters. ï‚· Drain dumpsters and/or dumpster pads to sanitary sewer. Keep dumpster lids closed. Install waterproof liners. F. Routine equipment, storage area, and structure inspection and maintenance practices to prevent drips, leaks or failures of hoses, valves, fittings, containers, pumps, or other systems that contain or transfer hazardous materials. SPCC Plan, Clare PUD 7/8/14 Page 10 ï‚· Inspect container storage areas regularly for corrosion, structural failure, spills, leaks, overfills, and failure of piping systems. Check containers daily for leaks/spills. Replace containers, and replace and tighten bungs in drums as needed. ï‚· Inspect for leaks all incoming vehicles, parts, and equipment stored temporarily outside. ï‚· Inspect all BMPs regularly, particularly after a significant storm. Identify and correct deficiencies to ensure that the BMPs are functioning as intended. G. Site inspection procedures and frequency. ï‚· Inspect all potential sources of contamination daily and immediately after a major storm event. SPCC Plan, Clare PUD 7/8/14 Page 11 8. Spill Response Table 8A, below, outline the response procedures that the contractor shall follow for the scenarios described in the table below, indicating that if hazardous materials are encountered or spilled to soil or water (including stormwater, as described in Section 7C) during construction, the contractor shall do everything possible to control and contain the material until appropriate measures can be taken. The response procedures include a description of the actions that the contractor shall take to address each task shown in the table as well as the specific on-site, spill response equipment that shall be used to perform each task. If the contractor will use a Subcontractor for spill response, provide contact information for the Subcontractor in Table 1 and, in the appropriate table below, identify when the Subcontractor shall be used and the actions that the contractor shall take at the site while waiting for the Subcontractor to respond. If the contractor encounters unanticipated pre-existing contamination within the Project area during Project work, Contractor shall immediately notify the Department of Ecology and the City of Lynnwood immediately. SPCC Plan, Clare PUD 7/8/14 Page 12 Table 8A Spill Response Procedures, Including Actions to be Taken and Equipment to be Used Spill Response Task Hazardous Material and Clean Up Spilled Material Location Assess the Spill Secure the Area Contain and Eliminate the Spill Decontaminate Equipment Source Dispose of Spilled & Contaminated Material1 (e.g., include in this or other (e.g. identify how the spill source will (e.g., Identify how the spill will be cleaned up columns a description of the be contained and eliminated during whether in soil or water, including stormwater internal, emergency spill response) that has contacted petroleum product, fuel or assistance, and agency a hazardous material). Explain how the notifications that will be made spilled material and all cleanup supplies will as part of the response be disposed of; describe documentation procedures, referencing and substantiating such disposal that will be adding to Table 2.1 as provided to the Lynnwood Surface Water appropriate) Utility and when it will be provided. Notes: 1 Spilled fuel, petroleum product and hazardous materials, contaminated stormwater, contaminated soil and water, and all cleanup supplies shall be transported off site for disposal at a facility approved by the Department of Ecology. No potentially hazardous materials, contaminated soil or water, or cleanup supplies may be discharged to any sanitary sewer without approval of the local sewer authority. Contaminated stormwater will not be discharged to any sanitary sewer without approval of the local sewer authority. ï® Petroleum products, fuel, and hazardous material spills shall be addressed and shall be prevented from reaching storm drains or other discharge points. ï® It is acceptable to combine materials covered by the same response procedures, as long each material is clearly identified. SPCC Plan, Clare PUD 7/8/14 Page 13 9. Project Site Map A Project site map, clearly showing each of the following required or recommended items, is attached: A. Site location and boundaries; B. Site access roads; C. Drainage pathways from the site and on site storm collection; D. Nearby waterways and sensitive areas (Waterways include streams, creeks, sloughs, rivers, Puget Sound, etc. Sensitive areas are areas that typically contain populations that could be particularly sensitive to a hazardous materials spill or release. Such areas include wetlands, areas that provide habitat for threatened or endangered species, nursing homes, hospitals, child care centers, etc. Sensitive areas also include areas where groundwater is used for drinking water, such as wellhead protection zones and sole source aquifer recharge areas.); E. Hazardous materials, equipment, and decontamination areas identified in Section 4 (Potential Spill Sources), above; F. Pre-existing contamination or contaminant sources described in Section 5 (Pre-Existing Contamination), above; G. Spill prevention and response equipment described in Section 7 (Spill Prevention) and Section 8 (Spill Response), above; H. Recommend using Project-specific Plan Sheets or a consistent map scale with identifiable or readable map symbols for each Project SPCC Map; I. Locations of storage, stockpiles and existing buildings. SPCC Plan, Portage Creek â€“ Phase-I 7/8/14 Page 14 10. Spill Report Form(s) A copy of the spill report form that Contractors working in the City of Arlington shall use in the event of a release or spill is attached: SPCC Plan, Portage Creek â€“ Phase-I 7/8/14 Page 15 11. Plan Approval By signing below, the contractor acknowledges this SPCC Plan is supported by the contractor having the authority to commit the necessary resources, including labor, equipment, and materials, to expeditiously control and remove any harmful quantity of fuel, petroleum product or hazardous materials spilled or released to the waters or land of the State of Washington. The contractor further acknowledges this SPCC Plan meets all requirements of Lynnwood Municipal Code (LMC) 13.40 Stormwater Management and 13.45 Surface Water Quality. All personnel on project have read this SPCC Plan, understand its contents and have signed the SPCC Plan Acknowledgement Form. _______________________ ___________________________________ Date Contractor This SPCC Plan has been reviewed and approved by the City of Lynnwood Environmental and Surface Water Division. _______________________ ___________________________________ Date Darlene Little Engineering Tech 1 Surface Water Division City of Lynnwood _______________________ _________________________________ Date Jared Bond Environmental and Surface Water Supervisor City of Lynnwood SPCC Plan, Portage Creek â€“ Phase-I 7/8/14 Page 16 SPCC Plan Acknowledgement Form (to be signed by all Project personnel) This is to certify that I have read this Project SPCC Plan and understand its contents. I have attended a Project orientation meeting discussing the elements of this SPCC Plan and the safety and health hazards associated with SPCC operations to be performed at this Project. Failure to comply with the requirements contained in this SPCC Plan may result in my removal from the Project. PRINT NAME SIGNATURE DATE SPCC Plan, Portage Creek â€“ Phase-I 7/8/14 Page 17 APPENDIX A SPILL OR INCIDENT REPORT FORM Instructions: Complete for any type of petroleum product or hazardous materials/waste spill or incident. Provide a copy of this report to City of Arlington Surface Water Management. 1. Contractor: Name and Title of Person Responsible for Spill Response: ______________________________ Phone Number:_________________________________________________________________ 2. General Spill Information: Common Name of Spilled Substance: ______________________________________________ Quantity Spilled (Estimate): _______________________________________________________ Describe Concentration of Material (Estimate): ________________________________________ Date of Spill: _____/_____/______ Time Spill Started: _____ AM _____ PM Time Spill Ended: _____ AM _____ PM 3. Spill Location and Conditions: Project Title: ___________________________________________________________________ Street Address and/or Milepost, City: _______________________________________________ Weather Conditions: ____________________________________________________________ If Spill to Water, Name of Water Body (if ditch or culvert, identify the water body that the structure discharges to): ____________________________________________________________________________ Identify the Discharge Point: _____________________________________________________ Estimate the Depth and Width of the Water Body: ____________________________________ Estimate Flow Rate (i.e., slow, moderate, or fast): ____________________________________ Describe Environmental Damage (i.e., fish kill?): ______________________________________ 4. Actions Taken: To Contain Spill or Impact of Incident: ______________________________________________ To Cleanup Spill or Recover from Incident: ___________________________________________ To Remove Cleanup Material: _____________________________________________________ To Document Disposal: __________________________________________________________ To Prevent Reoccurrence: ________________________________________________________ SPCC Plan, Portage Creek â€“ Phase-I 7/8/14 Page 18 5. Reporting the Spill: Spills to water: Immediately call the National Response Center (1-800-424-8802), Emergency Management (1-800-258-5990), and the Ecology Northwest Regional Office (1-425-649-7000). Spills to soil that may be an immediate threat to health or the environment (i.e., explosive, flammable, toxic vapors, shallow groundwater, nearby creek, etc.): Call the Ecology Northwest Regional Office immediately (1-425-649-7000). If not immediately threatening, but may be a threat to human health or the environment, report to Ecology within 24 hours. Note: Project specific permits may have additional reporting requirements. List all agencies contacted; include names, dates, and phone numbers for people you spoke with: _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ Record ERTS #, if issued by Ecology: ______________________________________________ 6. Person Responsible for Managing Termination/Closure of Incident or Spill: Name and Phone: ______________________________________________________________ Address and Fax: _______________________________________________________________ 7. Additional Notes/Information (if necessary): SPCC Plan, Portage Creek â€“ Phase-I 7/8/14 Page 19 STORMWATER SITE PLAN For Portage Creek â€“ Phase-I Prepared for City of Arlington 238 N. Olympic Ave Arlington, WA 98223 360.403.3500 Project Site Location: XXX 207th Pl NE Arlington, WA 98223 Applicant: Contact: Portage Creek, LLC IECO 11926 127th Ave. NE P.O. Box 1478 Lake Stevens, WA 98258 Everett, WA 98206 425-303-9363 Tax Idâ€™s: 31051200301000 IECO Project: 15-0740 Certified Erosion and Sedimentation Control Lead: To be named by contractor Stormwater Site Plan Prepared By: Jacob D. Mealey, E.I.T. Stormwater Site Plan Preparation Date: February 1, 2016 Approximate Construction Date: June 1, 2016 P.O Box 1478 ï³ Everett, WA 98206 ï³ P: 425.303.9363 F: 425.303.9362 ï³ info@insightengineering.net TABLE OF CONTENTS 1.0 Executive Summary ................................................................................................................3 1.1 Minimum Requirements Summary ..............................................................................................7 2.0 Existing Conditions ................................................................................................................9 3.0 Offsite Analysis .....................................................................................................................11 3.1 Upstream Analysis .....................................................................................................................14 3.2 Downstream Analysis ................................................................................................................14 4.0 Developed Conditions ..........................................................................................................16 5.0 Site Hydraulic ........................................................................................................................16 5.1 Existing Basin Summary ............................................................................................................18 5.2 Developed Basin Summary ........................................................................................................18 6.0 Appendix ...............................................................................................................................20 Figures Figure 1 - Minimum Requirements Flow Chart .........................................................................3 Figure 2 - Vicinity Map .................................................................................................................6 Figure 3 - Soil Map ......................................................................................................................10 Figure 4 â€“ Downstream Analysis Map .......................................................................................15 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 1 - Acronyms and Abbreviations _________________________________________ BMP Best Management Practices DOE Department of Ecology EDDS Engineering Design and Development Standards ESC Erosion and Sediment Control IECO Insight Engineering Company MR Minimum Requirement SWPPP Stormwater Pollution Prevention Plan SWMMWW Stormwater Management Manual for Western Washington TESC Temporary Erosion and Sediment Control WWHM Western Washington Hydrology Model Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 2 - 1.0 Executive Summary The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. Please refer to the Vicinity Map attached later in the section. This report follows the requirements defined in the 2005 DOE and the City of Arlington Requirements. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. Please refer to the soils map and descriptions attached later in this report for more details. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. Per Figure 2.2, (flow chart for new development requirements) Volume I of DOEâ€™s Stormwater Management Manual, Minimum requirements #1 through 10 shall apply for this project. See the Minimum Requirements Summary included later in this report. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 3 - design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. The water quality requirement would be obtained through routing the proposed drainage system to existing biosawales. The upstream flows will continue to bypass site through the existing drainage system that drains into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 4 - Figure 1 - Minimum Requirements (MR's) for New Development Projects Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 5 - FIGURE 2. VICINITY MAP SITE TAKEN FROM THE BING MAPS Figure 2 -Vicinity Map Portage Creek Arlington, Washington SCALE: DATE 2/2/16 JOB #: 15-0740 P.O. Box 1478 Everett, WA 98206 NTS : 425-303-9363, 425-303-9362 f. BY FILE NAME: Info@insightengineering.net JDM : 15-0740 /doc/Stormwater Site Plan Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 6 - 1.1 Minimum Requirements Summary MR : Minimum Requirement SWPPP : Stormwater Pollution Prevention Plan MR #1 Stormwater Site Plan Narrative: The Stormwater Site Plan preparation follows the City of Arlingon requirements and in accordance with DOE's 2005 SWMMWW. Refer to the executive summary within Section 1.0. MR #2 SWPPP Narrative: Refer to Appendix â€“A for the proposed SWPPP for the project. MR #3 Water pollution source control for new development: No source control pollutants pertains to the proposed project. MR #4 Preservation of Natural Drainage Systems and outfalls: The pond outlet will continue to its natural drainage path. MR #5 Onsite Stormwater Management: The yard and roof drains will be connected towards an on-site drainage system system. MR #6 Runoff Treatment: The water quality requirement would be obtained through routing the proposed drainage system to existing biosawales. MR #7 Flow Control: The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 7 - completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. MR #8 Wetlands protection: There are no wetlands located within the site. MR #9 Basin/Watershed Planning: Water quality and detention will be provided by the existing bioswales and pond. The existing pond will be revised according to the additional anticipated runoff. MR #10 Operations and Maintenance: Refer to Appendix â€“ B for a complete Operations and Maintenance Manual. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 8 - 2.0 Existing Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. Please refer to the soils map and descriptions attached later in this report for more details. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 9 - FIGURE 3. SOIL MAP SITE SOILS LEGEND 39â€”Norma loam 48â€”Pastik silt loam, 8 to 25 percent slopes 83â€”Water Figure 3 - Soil Map Portage Creek Arlington, Washington SCALE: DATE: 2/2/16 JOB #: 15-0740 P.O. Box 1478 Everett, WA 98206 NONE 425-303-9363, 425-303-9362 f. FILE NAME: Info@insightengineering.net BY: JDM 15-0740 /doc/Stormwater Site Plan Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 10 - Snohomish County Area, Washington 39â€”Norma loam Map Unit Setting ï‚· National map unit symbol: 2hyx ï‚· Elevation: 0 to 1,000 feet ï‚· Mean annual precipitation: 35 to 60 inches ï‚· Mean annual air temperature: 48 to 52 degrees F ï‚· Frost-free period: 150 to 200 days ï‚· Farmland classification: Prime farmland if drained Map Unit Composition ï‚· Norma and similar soils: 85 percent ï‚· Minor components: 15 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Description of Norma Setting ï‚· Landform: Depressions, drainageways ï‚· Parent material: Alluvium Typical profile ï‚· H1 - 0 to 10 inches: ashy loam ï‚· H2 - 10 to 28 inches: sandy loam ï‚· H3 - 28 to 60 inches: sandy loam Properties and qualities ï‚· Slope: 0 to 3 percent ï‚· Depth to restrictive feature: More than 80 inches ï‚· Natural drainage class: Poorly drained ï‚· Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.57 to 1.98 in/hr) ï‚· Depth to water table: About 0 inches ï‚· Frequency of flooding: None ï‚· Frequency of ponding: Frequent ï‚· Available water storage in profile: Moderate (about 9.0 inches) Interpretive groups ï‚· Land capability classification (irrigated): None specified ï‚· Land capability classification (nonirrigated): 3w ï‚· Hydrologic Soil Group: B/D ï‚· Other vegetative classification: Seasonally Wet Soils (G002XN202WA) Minor Components Bellingham ï‚· Percent of map unit: 5 percent Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 11 - ï‚· Landform: Depressions Custer ï‚· Percent of map unit: 5 percent ï‚· Landform: Depressions Terric medisaprists ï‚· Percent of map unit: 3 percent ï‚· Landform: Depressions Alderwood ï‚· Percent of map unit: 2 percent Snohomish County Area, Washington 48â€”Pastik silt loam, 8 to 25 percent slopes Map Unit Setting ï‚· National map unit symbol: 2hz7 ï‚· Elevation: 200 to 800 feet ï‚· Mean annual precipitation: 45 to 70 inches ï‚· Mean annual air temperature: 45 to 46 degrees F ï‚· Frost-free period: 140 to 200 days ï‚· Farmland classification: Farmland of statewide importance Map Unit Composition ï‚· Pastik and similar soils: 100 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Description of Pastik Setting ï‚· Landform: Terraces ï‚· Parent material: Volcanic ash and lacustrine deposits Typical profile ï‚· H1 - 0 to 6 inches: ashy silt loam ï‚· H2 - 6 to 29 inches: ashy silt loam ï‚· H3 - 29 to 60 inches: silt loam Properties and qualities ï‚· Slope: 8 to 25 percent ï‚· Depth to restrictive feature: More than 80 inches ï‚· Natural drainage class: Moderately well drained ï‚· Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) ï‚· Depth to water table: About 18 to 30 inches ï‚· Frequency of flooding: None Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 12 - ï‚· Frequency of ponding: None ï‚· Available water storage in profile: Very high (about 14.3 inches) Interpretive groups ï‚· Land capability classification (irrigated): None specified ï‚· Land capability classification (nonirrigated): 4e ï‚· Hydrologic Soil Group: C ï‚· Other vegetative classification: Soils with Moderate Limitations (G002XN602WA) Snohomish County Area, Washington 83â€”Water Map Unit Composition ï‚· Water: 100 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 13 - 3.0 Offsite Analysis The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. No visible on-site drainage problems were observed at the time of field investigations. 3.1 Upstream Analysis The upstream flows will continue to bypass site through the existing drainage system that drains to into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. 3.2 Downstream Analysis The outlet for the proposed detention/retention pond will be connected to a dispersion trench to disperse the outlet flows to drain into to the existing adjacent onsite pond. The outlet from the existing onsite pond flows into a detention pond located on the neighboring property to the northwest. The outlet from that pond drains to the west and travels underneath S Stillaguamish Ave into Kruger Creek that flows east in an unrestricted manner for about 2,900 feet and flows into Portage Creek. Portage creek flows west in an unrestricted manner. This is where the 1-mile downstream analysis was completed. There do not appear to be any restrictions or erosion problems within 1 mile of the site. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 14 - FIGURE 4. DOWNSTREAM ANALYSIS MAP SITE Figure 4 - Downstream Analysis Map Portage Creek Arlington, Washington P.O. Box 1478 Everett, WA 98206 SCALE: DATE: 2/2/16 JOB #: 15-0740 425-303-9363, 425-303-9362 f. NONE Info@insightengineering.net FILE NAME: BY: JDM 15-0740 \docs\drainage report Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 15 - 4.0 Developed Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. Per Figure 2.2, (flow chart for new development requirements) Volume I of DOEâ€™s Stormwater Management Manual, Minimum requirements #1 through 10 shall apply for this project. See the Minimum Requirements Summary included later in this report. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. The Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 16 - water quality requirement would be obtained through routing the proposed drainage system to existing biosawales. The upstream flows will continue to bypass site through the existing drainage system that drains into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 17 - 5.0 Site Hydraulic Conditions Total area included in the analysis = 1.89 Acres From the Soil Conservation Service Map of Snohomish County, the majority of the site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. 5.1 Existing Basin Summary Clearing Area (All Phases) = 1.89 Acres Existing Pond = 1.51 Acres Upstream Road Easement = 1.37 Acres Upstream Parcel (31051200301500) = 2.81 Acres Upstream Parcel (31051200301400) = 6.96 Acres Total Existing Basin = 14.54 Acres Existing Impervious: Road = 0.81 Acres Sidewalk = 0.11 Acres Existing Pond = 1.51 Acres Total Site Impervious = 2.43 Acres Forested area = 12.11 Acres Refer to the Existing Basin Map and the following pages for more details. 5.2 Developed Basin Summary Total Developed Basin = 14.54 Acres Developed Impervious Areas: Site Impervious: Driveway = 0.17 Acres Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 18 - New Road = 0.22 Acres Roof = 0.56 Acres Existing Road = 0.81 Acres Existing Sidewalk = 0.11 Acres Existing Pond = 1.51 Acres Total Site Impervious = 3.38 Acres Developed Pervious Areas: Site Pervious: Pervious Area (Lawn) = 0.94 Acres Forested Area = 10.22 Acres Refer to the Developed Basin Map and the following pages for more details. Total Pond Volume required = 116,000 CF Total Pond Volume Provided = 116,000 CF Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 19 - WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: Portage Creek Ex pond Recalc Site Name: Portage Creek Site Address: XXX Arlington WA City : Arlington Report Date: 1/18/2016 Gage : Everett Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.20 Version : 2015/03/18 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE Name : Ex Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat 12.11 Pervious Total 12.11 Impervious Land Use Acres ROADS FLAT 0.81 SIDEWALKS FLAT 0.11 POND 1.51 Impervious Total 2.43 Basin Total 14.54 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : Dv Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 20 - Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat 10.22 C, Lawn, Flat .94 Pervious Total 11.16 Impervious Land Use Acres ROADS FLAT 1.03 ROOF TOPS FLAT 0.56 DRIVEWAYS FLAT 0.17 SIDEWALKS FLAT 0.11 POND 1.51 Impervious Total 3.38 Basin Total 14.54 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater Additional Pond StoragAdditional Pond Storag ___________________________________________________________________ Name : Additional Pond Storage Depth: 1.71 ft. Discharge Structure Riser Height: 1.71 ft. Riser Diameter: 29 in. Notch Type: Rectangular Notch Width: 2.400 ft. Notch Height: 0.500 ft. Element Flows To: Outlet 1 Outlet 2 ___________________________________________________________________ Irregular Pond Hydraulic Table Stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) Infilt(cfs) 138.00 1.723 0.000 0.000 0.000 138.02 1.719 0.032 0.000 0.000 138.04 1.715 0.065 0.000 0.000 138.06 1.712 0.097 0.000 0.000 138.08 1.708 0.130 0.000 0.000 138.10 1.704 0.162 0.000 0.000 138.11 1.700 0.195 0.000 0.000 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 21 - 138.13 1.697 0.227 0.000 0.000 138.15 1.693 0.259 0.000 0.000 138.17 1.689 0.291 0.000 0.000 138.19 1.686 0.323 0.000 0.000 138.21 1.682 0.355 0.000 0.000 138.23 1.678 0.387 0.000 0.000 138.25 1.674 0.419 0.000 0.000 138.27 1.671 0.451 0.000 0.000 138.29 1.667 0.482 0.000 0.000 138.30 1.663 0.514 0.000 0.000 138.32 1.660 0.545 0.000 0.000 138.34 1.656 0.577 0.000 0.000 138.36 1.652 0.608 0.000 0.000 138.38 1.649 0.640 0.000 0.000 138.40 1.645 0.671 0.000 0.000 138.42 1.641 0.702 0.000 0.000 138.44 1.638 0.733 0.000 0.000 138.46 1.634 0.764 0.000 0.000 138.48 1.630 0.795 0.000 0.000 138.49 1.627 0.826 0.000 0.000 138.51 1.623 0.857 0.000 0.000 138.53 1.619 0.888 0.000 0.000 138.55 1.616 0.918 0.000 0.000 138.57 1.612 0.949 0.000 0.000 138.59 1.608 0.980 0.000 0.000 138.61 1.605 1.010 0.000 0.000 138.63 1.601 1.041 0.000 0.000 138.65 1.597 1.071 0.000 0.000 138.67 1.594 1.101 0.000 0.000 138.68 1.590 1.131 0.000 0.000 138.70 1.586 1.162 0.000 0.000 138.72 1.583 1.192 0.000 0.000 138.74 1.579 1.222 0.000 0.000 138.76 1.575 1.252 0.000 0.000 138.78 1.572 1.281 0.000 0.000 138.80 1.568 1.311 0.000 0.000 138.82 1.565 1.341 0.000 0.000 138.84 1.561 1.371 0.000 0.000 138.86 1.557 1.400 0.000 0.000 138.87 1.554 1.430 0.000 0.000 138.89 1.550 1.459 0.000 0.000 138.91 1.547 1.489 0.000 0.000 138.93 1.543 1.518 0.000 0.000 138.95 1.539 1.547 0.000 0.000 138.97 1.536 1.576 0.000 0.000 138.99 1.532 1.606 0.000 0.000 139.01 1.529 1.635 0.000 0.000 139.03 1.525 1.664 0.000 0.000 139.05 1.521 1.692 0.000 0.000 139.06 1.518 1.721 0.000 0.000 139.08 1.514 1.750 0.000 0.000 139.10 1.511 1.779 0.000 0.000 139.12 1.507 1.807 0.000 0.000 139.14 1.504 1.836 0.000 0.000 139.16 1.500 1.865 0.000 0.000 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 22 - 139.18 1.496 1.893 0.000 0.000 139.20 1.493 1.921 0.000 0.000 139.22 1.489 1.950 0.003 0.000 139.24 1.486 1.978 0.031 0.000 139.25 1.482 2.006 0.073 0.000 139.27 1.479 2.034 0.126 0.000 139.29 1.475 2.062 0.187 0.000 139.31 1.472 2.090 0.256 0.000 139.33 1.468 2.118 0.332 0.000 139.35 1.465 2.146 0.414 0.000 139.37 1.461 2.174 0.501 0.000 139.39 1.458 2.201 0.595 0.000 139.41 1.454 2.229 0.693 0.000 139.43 1.451 2.257 0.796 0.000 139.44 1.447 2.284 0.904 0.000 139.46 1.444 2.312 1.017 0.000 139.48 1.440 2.339 1.133 0.000 139.50 1.437 2.366 1.254 0.000 139.52 1.433 2.393 1.379 0.000 139.54 1.430 2.421 1.508 0.000 139.56 1.426 2.448 1.640 0.000 139.58 1.423 2.475 1.776 0.000 139.60 1.419 2.502 1.916 0.000 139.62 1.416 2.529 2.059 0.000 139.63 1.412 2.555 2.206 0.000 139.65 1.409 2.582 2.356 0.000 139.67 1.405 2.609 2.509 0.000 139.69 1.402 2.636 2.666 0.000 139.71 1.398 2.662 2.825 0.000 ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration ___________________________________________________________________ Predeveloped Landuse Totals for POC #1 Total Pervious Area:12.11 Total Impervious Area:2.43 ___________________________________________________________________ Mitigated Landuse Totals for POC #1 Total Pervious Area:11.16 Total Impervious Area:3.38 ___________________________________________________________________ Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 1.516944 5 year 2.109568 10 year 2.552211 25 year 3.171481 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 23 - 50 year 3.678219 100 year 4.225488 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.713636 5 year 0.952544 10 year 1.128971 25 year 1.373552 50 year 1.572121 100 year 1.78528 ___________________________________________________________________ Stream Protection Duration Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 1.791 0.623 1950 1.902 0.743 1951 1.606 0.650 1952 1.380 0.622 1953 1.768 0.494 1954 3.288 0.686 1955 1.801 1.068 1956 1.033 0.768 1957 1.699 1.010 1958 3.325 1.077 1959 1.310 0.800 1960 1.498 0.827 1961 4.437 1.078 1962 1.488 0.743 1963 2.189 0.816 1964 1.102 0.754 1965 1.139 0.580 1966 1.142 0.472 1967 2.518 0.845 1968 1.487 1.043 1969 3.824 0.649 1970 1.118 0.569 1971 1.643 0.735 1972 1.944 1.022 1973 1.638 0.553 1974 2.016 0.654 1975 1.690 0.603 1976 1.064 0.656 1977 1.025 0.550 1978 1.031 0.573 1979 2.370 1.218 1980 1.248 0.689 1981 1.126 0.542 1982 1.069 0.902 1983 1.627 0.614 1984 1.355 0.710 1985 1.782 0.904 1986 2.541 1.579 1987 1.549 0.920 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 24 - 1988 1.370 0.602 1989 1.506 0.471 1990 1.143 0.663 1991 1.247 0.655 1992 1.420 0.617 1993 1.114 0.523 1994 1.093 0.554 1995 0.924 0.728 1996 1.758 1.131 1997 2.757 2.034 1998 1.727 0.623 1999 0.984 0.587 2000 2.687 0.514 2001 0.914 0.393 2002 0.886 0.656 2003 1.203 0.486 2004 2.273 0.857 2005 1.104 0.698 2006 2.184 1.126 2007 1.991 0.911 2008 1.625 1.656 2009 1.201 0.702 ___________________________________________________________________ Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 4.4371 2.0335 2 3.8236 1.6560 3 3.3248 1.5789 4 3.2878 1.2185 5 2.7574 1.1310 6 2.6870 1.1257 7 2.5405 1.0785 8 2.5183 1.0770 9 2.3695 1.0679 10 2.2726 1.0435 11 2.1886 1.0221 12 2.1838 1.0099 13 2.0164 0.9205 14 1.9908 0.9111 15 1.9445 0.9038 16 1.9016 0.9022 17 1.8011 0.8565 18 1.7907 0.8453 19 1.7818 0.8269 20 1.7679 0.8156 21 1.7581 0.7999 22 1.7269 0.7682 23 1.6989 0.7543 24 1.6903 0.7428 25 1.6426 0.7427 26 1.6378 0.7352 27 1.6273 0.7282 28 1.6247 0.7099 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 25 - 29 1.6058 0.7022 30 1.5487 0.6982 31 1.5058 0.6889 32 1.4978 0.6859 33 1.4879 0.6626 34 1.4873 0.6559 35 1.4203 0.6558 36 1.3804 0.6550 37 1.3696 0.6542 38 1.3547 0.6501 39 1.3096 0.6489 40 1.2480 0.6233 41 1.2473 0.6227 42 1.2028 0.6222 43 1.2007 0.6173 44 1.1435 0.6139 45 1.1415 0.6028 46 1.1389 0.6018 47 1.1256 0.5870 48 1.1175 0.5798 49 1.1141 0.5730 50 1.1037 0.5685 51 1.1019 0.5537 52 1.0928 0.5528 53 1.0695 0.5502 54 1.0641 0.5419 55 1.0328 0.5234 56 1.0313 0.5139 57 1.0253 0.4942 58 0.9836 0.4860 59 0.9244 0.4721 60 0.9137 0.4714 61 0.8864 0.3929 ___________________________________________________________________ Stream Protection Duration POC #1 The Facility PASSED The Facility PASSED. Flow(cfs) Predev Mit Percentage Pass/Fail 0.7585 1813 921 50 Pass 0.7880 1566 809 51 Pass 0.8175 1369 674 49 Pass 0.8469 1195 588 49 Pass 0.8764 1058 528 49 Pass 0.9059 955 475 49 Pass 0.9354 854 436 51 Pass 0.9649 763 403 52 Pass 0.9944 695 363 52 Pass 1.0239 634 320 50 Pass 1.0534 581 289 49 Pass 1.0829 540 259 47 Pass 1.1124 470 247 52 Pass Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 26 - 1.1419 420 231 55 Pass 1.1714 382 223 58 Pass 1.2009 353 208 58 Pass 1.2304 318 196 61 Pass 1.2598 281 191 67 Pass 1.2893 264 183 69 Pass 1.3188 238 169 71 Pass 1.3483 224 147 65 Pass 1.3778 204 130 63 Pass 1.4073 174 112 64 Pass 1.4368 159 97 61 Pass 1.4663 148 88 59 Pass 1.4958 132 78 59 Pass 1.5253 121 67 55 Pass 1.5548 106 57 53 Pass 1.5843 97 40 41 Pass 1.6138 88 32 36 Pass 1.6432 78 23 29 Pass 1.6727 73 17 23 Pass 1.7022 65 15 23 Pass 1.7317 60 10 16 Pass 1.7612 53 8 15 Pass 1.7907 49 6 12 Pass 1.8202 42 6 14 Pass 1.8497 37 5 13 Pass 1.8792 35 5 14 Pass 1.9087 33 5 15 Pass 1.9382 30 4 13 Pass 1.9677 29 3 10 Pass 1.9972 26 2 7 Pass 2.0266 24 1 4 Pass 2.0561 23 0 0 Pass 2.0856 23 0 0 Pass 2.1151 21 0 0 Pass 2.1446 20 0 0 Pass 2.1741 18 0 0 Pass 2.2036 15 0 0 Pass 2.2331 14 0 0 Pass 2.2626 14 0 0 Pass 2.2921 13 0 0 Pass 2.3216 12 0 0 Pass 2.3511 12 0 0 Pass 2.3806 10 0 0 Pass 2.4100 10 0 0 Pass 2.4395 10 0 0 Pass 2.4690 10 0 0 Pass 2.4985 10 0 0 Pass 2.5280 8 0 0 Pass 2.5575 7 0 0 Pass 2.5870 7 0 0 Pass 2.6165 7 0 0 Pass 2.6460 7 0 0 Pass 2.6755 7 0 0 Pass 2.7050 6 0 0 Pass 2.7345 6 0 0 Pass Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 27 - 2.7640 5 0 0 Pass 2.7934 5 0 0 Pass 2.8229 5 0 0 Pass 2.8524 5 0 0 Pass 2.8819 5 0 0 Pass 2.9114 5 0 0 Pass 2.9409 5 0 0 Pass 2.9704 5 0 0 Pass 2.9999 5 0 0 Pass 3.0294 5 0 0 Pass 3.0589 5 0 0 Pass 3.0884 5 0 0 Pass 3.1179 5 0 0 Pass 3.1474 5 0 0 Pass 3.1768 5 0 0 Pass 3.2063 5 0 0 Pass 3.2358 5 0 0 Pass 3.2653 5 0 0 Pass 3.2948 4 0 0 Pass 3.3243 4 0 0 Pass 3.3538 3 0 0 Pass 3.3833 3 0 0 Pass 3.4128 3 0 0 Pass 3.4423 3 0 0 Pass 3.4718 3 0 0 Pass 3.5013 3 0 0 Pass 3.5308 3 0 0 Pass 3.5602 3 0 0 Pass 3.5897 3 0 0 Pass 3.6192 3 0 0 Pass 3.6487 3 0 0 Pass 3.6782 3 0 0 Pass _____________________________________________________ ___________________________________________________________________ Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. ___________________________________________________________________ ___________________________________________________________________ LID Report LID Technique Used for Total Volumn Volumn Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volumn Volumn Volumn Water Quality Treatment Facility (ac-ft) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Additional Pond Storage POC N 1245.18 N Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 28 - 0.00 Total Volume Infiltrated 1245.18 0.00 0.00 0.00 0.00 0% No Treat. Credit Compliance with LID Standard 8 Duration Analysis Result = Passed ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ 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. 2005-2016; All Rights Reserved. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 29 - 6.0 Appendix A. Stormwater Pollution Prevention Plan B. Operations and Maintenance Manual C. Bond Quantities Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 30 - A. STORMWATER POLLUTION PREVENTION PLAN This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the Construction stormwater permit requirements for the Portage Creek - Phase-I project in Arlington, Washington. It is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. 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. This SWPPP was prepared based on the requirements set forth in the Construction Stormwater General Permit and in the Stormwater Management Manual for Western Washington (SWMMWW 2005). Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 31 - The 12 BMP Elements 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. 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. Install the temporary construction entrance, according to the approved construction plans, prior to any clearing or grading activities. Maintain until the access road is paved. 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. In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements. A sediment pond is proposed to control flow rates during grading activity. Element #4 â€“ Install Sediment Controls Install silt fencing, according to the approved plans, prior to any clearing or grading activities. Maintain until all construction activities are completed. Element #5 â€“ Stabilize Soils Exposed and un-worked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. Apply temporary hydro-seed to exposed and un-worked soils, according to the approved construction plans, as needed to prevent erosion during site grading. Apply permanent hydro-seed to areas at final grade as site grading is completed. Apply mulching to exposed and un-worked soils, according to the approved construction plans, as needed to prevent erosion during site grading. Maintain until site grading is completed and permanent hydro-seed is applied. Cover stockpiles with plastic sheeting, according to the approved construction plans, as needed to prevent erosion during site grading. Maintain until stockpiles are removed from site. Element #6 â€“ Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes erosion. The following specific BMPs will be used to protect slopes for this project. 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 Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 32 - 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. 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. 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 housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. Element #10 â€“ Control Dewatering There will be no dewatering expected as part of this proposal. If it occurs, Baker tanks will be used for dewatering. Element #11 â€“ Maintain BMPs All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMPâ€™s specifications. Visual monitoring of the BMPs will be conducted at least once every calendar week and within 24 hours of any rainfall event that causes a discharge from the site. If the site becomes inactive, and is temporarily stabilized, the inspection frequency will be reduced to once every month. All temporary erosion and sediment control BMPs shall be removed within 30 days after the final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be removed or stabilized on site. Disturbed soil resulting from removal of BMPs or vegetation shall be permanently stabilized. Element #12 â€“ Manage the Project Erosion and sediment control BMPs for this project have been designed based on the following principles: Design the project to fit the existing topography, soils, and drainage patterns; 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 and Schedule major earthwork during the dry season. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven (7) days following the inspection. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 33 - B. OPERATION AND MAINTENANCE MANUAL The facilities that require periodic maintenance for this project are as follows. o Catch basins o Catch basin Inserts Refer to the following pages for facilities that require maintenance. Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 34 - C. BOND QUANTITIES Insight Engineering Co. â€“Stormwater Site Plan 2/1/16 - 35 - 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 3/2/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 1. MH Sht. C1-1 Provide Basin Area of south side of 207th St. that The total existing basin contributing to the existing contributes an offsite run on for total pond capacity. pond is 14.54 Acres. A note has been added to sheet C1.1. 2. MH Sht. C 2.0 It appears that the grading will remove more than the Please see the revised grading plan. We are not recommended amount contained within the Geotechnical removing more than 2â€™ of soil. Report. 3. MH Sht. C 2.1 Identify where catch basin inserts are to be placed on the All proposed catch basin inserts have been added plan sheet. to sheet C2.1. 4. MH Sht. C 2.1 The installation of pea gravel is critical in this installation Refer to detail 3 on sheet C2.1 for silt fence detail of silt fence since there is no storage area for runoff. that references the installation of pea gravel at the base of the silt fence. 5. MH Sht. C 3.0 How is water quality and flow control being addressed by Water quality and flow control are being met by this proposed system? directing the proposed runoff to the vegetation filter strip and flow control is handled with a weir at the outlet of the pond. 6. MH Sht. C 3.0 Why is the runoff not being directed to a level spreader A level spreader has been proposed. Refer to sheet before entering pond as originally discussed? C3.0. 7. MH Sht. C 3.0 Where is the proposed weir design? Refer to sheet C3.0 for the proposed weir design. 8. MH Sht. C 3.0 Delineate the Critical Area Buffer on this sheet. The critical area buffer is shown on sheet C3.0. 9. MH General Upon review of the Geotechnical Report produced by Please see the site plan exhibit with the cross Associated Earth Sciences, Inc. whereas it states, that per sections. their recommendation, no homes should be built any further east than Geologic Cross â€“ Section C-Câ€™ because of the high risk of future impacts caused by landslide activity.. Please provide a sheet that also includes the proposed Phase II and Phase III along with Geologic Cross Sections A-Aâ€™, B-Bâ€™ and C-Câ€™ delineated upon it. 10. GS Sht. 4.0 Show water meters in proper location between curb and The proposed location of water meters have been sidewalk per COA Standard W-070. revised to be located within the planter per detail. 11. GS Sht. 4.0 Show water main in proper alignment with valving. The water main and valving has been aligned. Page 1 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 3/2/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 12. GS Sht. 4.0 Show water valves in proper configuration (West-East Please refer to the revised plan. and South). 13. FR Sht. C 3.1 Elimination of two 6" sewer lines and replace with one 8" An 8â€ line is now proposed to serve the line is a cost savings and meets current standards for development. construction. Standards paragraphs are cited in the redlines. See Attachment 1-A. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. Page 2 of 3 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA 98223 360-403-3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 3/2/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Addâ€™l Ref. City Comment Response/Resolution Spec. Ref. Approved 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. Page 3 of 3 R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's STORMWATER SITE PLAN For Portage Creek â€“ Phase-I Prepared for City of Arlington 238 N. Olympic Ave Arlington, WA 98223 360.403.3500 Project Site Location: XXX 207th Pl NE Arlington, WA 98223 Applicant: Contact: Portage Creek, LLC IECO 11926 127th Ave. NE P.O. Box 1478 Lake Stevens, WA 98258 Everett, WA 98206 425-303-9363 Tax Idâ€™s: 31051200301000 IECO Project: 15-0740 Certified Erosion and Sedimentation Control Lead: To be named by contractor Stormwater Site Plan Prepared By: Jacob D. Mealey, E.I.T. Stormwater Site Plan Preparation Date: February 1, 2016 Date Revised: April 1, 2016 Approximate Construction Date: May 1, 2016 P.O Box 1478 ï³ Everett, WA 98206 ï³ P: 425.303.9363 F: 425.303.9362 ï³ info@insightengineering.net TABLE OF CONTENTS 1.0 Executive Summary ................................................................................................................3 1.1 Minimum Requirements Summary ..............................................................................................7 2.0 Existing Conditions ................................................................................................................9 3.0 Offsite Analysis .....................................................................................................................11 3.1 Upstream Analysis .....................................................................................................................14 3.2 Downstream Analysis ................................................................................................................14 4.0 Developed Conditions ..........................................................................................................16 5.0 Site Hydraulic ........................................................................................................................17 5.1 Existing Basin Summary ............................................................................................................19 5.2 Developed Basin Summary ........................................................................................................19 5.3 Water Quality .............................................................................................................................21 6.0 Conveyance Analysis and Design .......................................................................................22 7.0 Appendix ...............................................................................................................................27 Figures Figure 1 - Minimum Requirements Flow Chart .........................................................................3 Figure 2 - Vicinity Map .................................................................................................................6 Figure 3 - Soil Map ......................................................................................................................10 Figure 4 â€“ Downstream Analysis Map .......................................................................................15 Figure 5 â€“ Upstream Analysis Map ............................................................................................16 Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 1 - Acronyms and Abbreviations _________________________________________ BMP Best Management Practices DOE Department of Ecology EDDS Engineering Design and Development Standards ESC Erosion and Sediment Control IECO Insight Engineering Company MR Minimum Requirement SWPPP Stormwater Pollution Prevention Plan SWMMWW Stormwater Management Manual for Western Washington TESC Temporary Erosion and Sediment Control WWHM Western Washington Hydrology Model Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 2 - 1.0 Executive Summary The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. Please refer to the Vicinity Map attached later in the section. This report follows the requirements defined in the 2005 DOE and the City of Arlington Requirements. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. The site contains critical areas, Critical Area A and Critical Area B, each with associated buffers. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. Please refer to the soils map and descriptions attached later in this report for more details. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. Per Figure 2.2, (flow chart for new development requirements) Volume I of DOEâ€™s Stormwater Management Manual, Minimum requirements #1 through 10 shall apply for this project. See the Minimum Requirements Summary included later in this report. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 3 - channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. The water quality requirement would be obtained through routing the proposed drainage system a filter strip per BMP T9.50 located downstream of the level spreader. The upstream flows will continue to bypass site through the existing drainage system that drains into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 4 - Figure 1 - Minimum Requirements (MR's) for New Development Projects Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 5 - FIGURE 2. VICINITY MAP SITE TAKEN FROM THE BING MAPS Figure 2 -Vicinity Map Portage Creek Arlington, Washington SCALE: DATE P.O. Box 1478 Everett, WA 98206 NTS : 4/19/16 JOB #: 15-0740 425-303-9363, 425-303-9362 f. BY FILE NAME: Info@insightengineering.net JDM : 15-0740 /doc/Stormwater Site Plan Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 6 - 1.1 Minimum Requirements Summary MR : Minimum Requirement SWPPP : Stormwater Pollution Prevention Plan MR #1 Stormwater Site Plan Narrative: The Stormwater Site Plan preparation follows the City of Arlingon requirements and in accordance with DOE's 2005 SWMMWW. Refer to the executive summary within Section 1.0. MR #2 SWPPP Narrative: Refer to Appendix â€“A for the proposed SWPPP for the project. MR #3 Water pollution source control for new development: No source control pollutants pertains to the proposed project. MR #4 Preservation of Natural Drainage Systems and outfalls: The pond outlet will continue to its natural drainage path. MR #5 Onsite Stormwater Management: The yard and roof drains will be connected towards an on-site drainage system system. MR #6 Runoff Treatment: The water quality requirement would be obtained through routing the proposed drainage system a filter strip per BMP T9.50 located downstream of the level spreader. MR #7 Flow Control: The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 7 - for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. MR #8 Wetlands protection: The site contains critical areas, Critical Area A and Critical Area B, each with associated buffers. MR #9 Basin/Watershed Planning: Water quality and detention will be provided by the existing bioswales and pond. The existing pond will be revised according to the additional anticipated runoff. MR #10 Operations and Maintenance: Refer to Appendix â€“ B for a complete Operations and Maintenance Manual. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 8 - 2.0 Existing Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. The site contains critical areas, Critical Area A and Critical Area B, each with associated buffers. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. Please refer to the soils map and descriptions attached later in this report for more details. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 9 - FIGURE 3. SOIL MAP SITE SOILS LEGEND 39â€”Norma loam 48â€”Pastik silt loam, 8 to 25 percent slopes 83â€”Water Figure 3 - Soil Map Portage Creek Arlington, Washington SCALE: DATE: 4/19/16 JOB #: 15-0740 P.O. Box 1478 Everett, WA 98206 NONE 425-303-9363, 425-303-9362 f. FILE NAME: Info@insightengineering.net BY: JDM 15-0740 /doc/Stormwater Site Plan Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 10 - Snohomish County Area, Washington 39â€”Norma loam Map Unit Setting ï‚· National map unit symbol: 2hyx ï‚· Elevation: 0 to 1,000 feet ï‚· Mean annual precipitation: 35 to 60 inches ï‚· Mean annual air temperature: 48 to 52 degrees F ï‚· Frost-free period: 150 to 200 days ï‚· Farmland classification: Prime farmland if drained Map Unit Composition ï‚· Norma and similar soils: 85 percent ï‚· Minor components: 15 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Description of Norma Setting ï‚· Landform: Depressions, drainageways ï‚· Parent material: Alluvium Typical profile ï‚· H1 - 0 to 10 inches: ashy loam ï‚· H2 - 10 to 28 inches: sandy loam ï‚· H3 - 28 to 60 inches: sandy loam Properties and qualities ï‚· Slope: 0 to 3 percent ï‚· Depth to restrictive feature: More than 80 inches ï‚· Natural drainage class: Poorly drained ï‚· Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.57 to 1.98 in/hr) ï‚· Depth to water table: About 0 inches ï‚· Frequency of flooding: None ï‚· Frequency of ponding: Frequent ï‚· Available water storage in profile: Moderate (about 9.0 inches) Interpretive groups ï‚· Land capability classification (irrigated): None specified ï‚· Land capability classification (nonirrigated): 3w ï‚· Hydrologic Soil Group: B/D ï‚· Other vegetative classification: Seasonally Wet Soils (G002XN202WA) Minor Components Bellingham ï‚· Percent of map unit: 5 percent Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 11 - ï‚· Landform: Depressions Custer ï‚· Percent of map unit: 5 percent ï‚· Landform: Depressions Terric medisaprists ï‚· Percent of map unit: 3 percent ï‚· Landform: Depressions Alderwood ï‚· Percent of map unit: 2 percent Snohomish County Area, Washington 48â€”Pastik silt loam, 8 to 25 percent slopes Map Unit Setting ï‚· National map unit symbol: 2hz7 ï‚· Elevation: 200 to 800 feet ï‚· Mean annual precipitation: 45 to 70 inches ï‚· Mean annual air temperature: 45 to 46 degrees F ï‚· Frost-free period: 140 to 200 days ï‚· Farmland classification: Farmland of statewide importance Map Unit Composition ï‚· Pastik and similar soils: 100 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Description of Pastik Setting ï‚· Landform: Terraces ï‚· Parent material: Volcanic ash and lacustrine deposits Typical profile ï‚· H1 - 0 to 6 inches: ashy silt loam ï‚· H2 - 6 to 29 inches: ashy silt loam ï‚· H3 - 29 to 60 inches: silt loam Properties and qualities ï‚· Slope: 8 to 25 percent ï‚· Depth to restrictive feature: More than 80 inches ï‚· Natural drainage class: Moderately well drained ï‚· Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) ï‚· Depth to water table: About 18 to 30 inches ï‚· Frequency of flooding: None Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 12 - ï‚· Frequency of ponding: None ï‚· Available water storage in profile: Very high (about 14.3 inches) Interpretive groups ï‚· Land capability classification (irrigated): None specified ï‚· Land capability classification (nonirrigated): 4e ï‚· Hydrologic Soil Group: C ï‚· Other vegetative classification: Soils with Moderate Limitations (G002XN602WA) Snohomish County Area, Washington 83â€”Water Map Unit Composition ï‚· Water: 100 percent ï‚· Estimates are based on observations, descriptions, and transects of the mapunit. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 13 - 3.0 Offsite Analysis The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. No visible on-site drainage problems were observed at the time of field investigations. 3.1 Upstream Analysis The upstream flows will continue to bypass site through the existing drainage system that drains to into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. 3.2 Downstream Analysis The outlet for the proposed detention/retention pond will be connected to a dispersion trench to disperse the outlet flows to drain into to the existing adjacent onsite pond. The outlet from the existing onsite pond flows into a detention pond located on the neighboring property to the northwest. The outlet from that pond drains to the west and travels underneath S Stillaguamish Ave into Kruger Creek that flows east in an unrestricted manner for about 2,900 feet and flows into Portage Creek. Portage creek flows west in an unrestricted manner. This is where the 1-mile downstream analysis was completed. There do not appear to be any restrictions or erosion problems within 1 mile of the site. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 14 - FIGURE 4. DOWNSTREAM ANALYSIS MAP SITE Figure 4 - Downstream Analysis Map Portage Creek Arlington, Washington P.O. Box 1478 Everett, WA 98206 SCALE: DATE: 4/19/16 JOB #: 15-0740 425-303-9363, 425-303-9362 f. NONE Info@insightengineering.net FILE NAME: BY: JDM 15-0740 \docs\drainage report Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 15 - FIGURE 5. UPSTREAM ANALYSIS MAP Pond (1.51 Ac) Upstream Parcel (6.96 Ac) Clearing Area (1.89 Ac) Upstream Parcel (2.81 Ac) Easement Rd (1.37 Ac) Figure 5 - Upstream Analysis Map Portage Creek Arlington, Washington P.O. Box 1478 Everett, WA 98206 SCALE: DATE: 4/19/16 JOB #: 15-0740 425-303-9363, 425-303-9362 f. NONE Info@insightengineering.net FILE NAME: BY: JDM 15-0740 \docs\drainage report Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 16 - 4.0 Developed Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The site contains critical areas, Critical Area A and Critical Area B, each with associated buffers. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. Per Figure 2.2, (flow chart for new development requirements) Volume I of DOEâ€™s Stormwater Management Manual, Minimum requirements #1 through 10 shall apply for this project. See the Minimum Requirements Summary included later in this report. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The hydraulic analysis for the site was calculated to include the entire proposed development including the future phases for the site. A weir will be added to the existing outlet channel to provide adequate flow control for the existing pond. The existing pond depth for design purposes was taken as 1.5-ft however the actual pond depth is much greater. The total existing drainage basin as well as the proposed development for all phases was included in the developed drainage basin in order to calculate the required volume for the pond. The water surface elevation for the existing pond will rise 1/2 â€“foot due to the completed development of all phases based on the hydraulic calculations for the pond. The detention volume was calculated in WWHM 2012, refer to section 5.0 for the hydraulic analysis. The existing pond volume at the current water surface elevation (with 1.5-ft depth) is 102,802 CF. The required volume with the construction of the proposed development is 116,000 CF. Therefore the pond with the Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 17 - installation of the proposed weir will increase the storage volume of the pond by 13,198 CF. The water quality requirement would be obtained through routing the proposed drainage system a filter strip per BMP T9.50 located downstream of the level spreader. The upstream flows will continue to bypass site through the existing drainage system that drains into the existing bioswale and onsite pond. The existing drainage systems will remain undisturbed. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 18 - 5.0 Site Hydraulic Conditions Total area included in the analysis = 1.89 Acres From the Soil Conservation Service Map of Snohomish County, the majority of the site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. 5.1 Existing Basin Summary Clearing Area (All Phases) = 1.89 Acres Existing Pond = 1.51 Acres Upstream Road Easement = 1.37 Acres Upstream Parcel (31051200301500) = 2.81 Acres Upstream Parcel (31051200301400) = 6.96 Acres Total Existing Basin = 14.54 Acres Existing Impervious: Road = 0.81 Acres Sidewalk = 0.11 Acres Existing Pond = 1.51 Acres Total Site Impervious = 2.43 Acres Forested area = 12.11 Acres Refer to the Existing Basin Map and the following pages for more details. 5.2 Developed Basin Summary Total Developed Basin = 14.54 Acres Developed Impervious Areas: Site Impervious: Driveway = 0.17 Acres Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 19 - New Road = 0.22 Acres Roof = 0.56 Acres Existing Road = 0.81 Acres Existing Sidewalk = 0.11 Acres Existing Pond = 1.51 Acres Total Site Impervious = 3.38 Acres Developed Pervious Areas: Site Pervious: Pervious Area (Lawn) = 0.94 Acres Forested Area = 10.22 Acres Refer to the Developed Basin Map and the following pages for more details. Total Pond Volume required = 116,000 CF Total Pond Volume Provided = 116,000 CF Refer to Appendix-D for the WWHM report. Orifice Sizing: The orifice was sized based on the 2-year existing flow rate in order to let the bypass flows from the upstream areas continue to flow through the channel at the same rate of the predeveloped flows. Q = 1.52 cfs (The 2-year Ex. flow in cubic feet per second (ft3/sec)) h = 0.1 ft (Differential head across the orifice) K = 0.62 D = Orifice diameter ð‘¸ ð’…=âˆš ðŸðŸ—.ðŸ”ðŸ‘ð‘²âˆšð’‰ ðŸ.ðŸ“ðŸ ð’…=âˆš =ðŸŽ.ðŸ”ðŸ‘ ð‘ð‘»=ðŸ•.ðŸ“ðŸ’ ð’Šð’ ðŸðŸ—.ðŸ”ðŸ‘(ðŸŽ.ðŸ”ðŸ)âˆšðŸŽ.ðŸ Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 20 - 5.3 Water Quality The water quality requirement would be obtained through routing the proposed drainage system a filter strip per BMP T9.50 located downstream of the level spreader. The filter strip slope will be 2.5 percent and the flow path length will be 20 feet. Based on Figure 9.10, the required length for the filter strip is 5.2-ft. The design proposes a conservative filter strip length of 30-ft. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 21 - 6.0 Conveyance Analysis and Design A conveyance analysis was performed using â€œStormshedâ€ software by Engenious Systems using the â€œRationalâ€ method to analyze onsite conveyance system. Rational Methodology was used since the basin is less than 25 acres. The pipes were analyzed for the developed 100-yr storm event. The 100yr peak flow for the project is only 1.41 cfs. The 12-inch system can easily convey the proposed runoff from the site. Therefore the proposed 12-inch system for the project is sufficient to convey the peak runoff from the site. The roof drains will consist of a 6-inch system at 0.5 percent minimum. Conveyance Layout 100-yr Headwater Calculation Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 22 - ROUTEHYD [] THRU [Untitled] USING Everett AND [100 yr] NOTZERO RELATIVE RATIONAL Reach Area TC Flow Full Q Full nDepth nVel fVel CBasin / Size ID (ac) (min) (cfs) (cfs) ratio (ft) (ft/s) (ft/s) Hyd 12" P-001 0.7200 6.24 1.3444 2.7366 0.49 0.4946 3.4710 3.4843 DA Diam From Node To Node Rch Loss (ft) App (ft) Bend (ft) Junct Loss (ft) HW Loss Elev (ft) Max El (ft) 100.2446 N-001 N-002 100.7191 ------ ------ ------ 100.7191 108.0000 Record Id: DA Design Method Rational IDF Table: Everett Composite C Calc Description SubArea Sub c Pavement and roofs (n=0.90) 0.31 ac 0.90 Lawn 0.41 ac 0.25 Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed TC 6.00 min Directly Connected TC 6.00min Record Id: N-001 Descrip: Prototype Record Increment 0.10 ft Start El. 100.0000 ft Max El. 108.0000 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Condition Existing Stage Storage Rating Curve 100.0000 ft 0.0000 cf 104.1000 ft 80.5035 cf 100.1000 ft 1.9635 cf 104.2000 ft 82.4670 cf 100.2000 ft 3.9270 cf 104.3000 ft 84.4305 cf 100.3000 ft 5.8905 cf 104.4000 ft 86.3940 cf 100.4000 ft 7.8540 cf 104.5000 ft 88.3575 cf 100.5000 ft 9.8175 cf 104.6000 ft 90.3210 cf 100.6000 ft 11.7810 cf 104.7000 ft 92.2845 cf 100.7000 ft 13.7445 cf 104.8000 ft 94.2480 cf 100.8000 ft 15.7080 cf 104.9000 ft 96.2115 cf Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 23 - 100.9000 ft 17.6715 cf 105.0000 ft 98.1750 cf 101.0000 ft 19.6350 cf 105.1000 ft 100.1385 cf 101.1000 ft 21.5985 cf 105.2000 ft 102.1020 cf 101.2000 ft 23.5620 cf 105.3000 ft 104.0655 cf 101.3000 ft 25.5255 cf 105.4000 ft 106.0290 cf 101.4000 ft 27.4890 cf 105.5000 ft 107.9925 cf 101.5000 ft 29.4525 cf 105.6000 ft 109.9560 cf 101.6000 ft 31.4160 cf 105.7000 ft 111.9195 cf 101.7000 ft 33.3795 cf 105.8000 ft 113.8830 cf 101.8000 ft 35.3430 cf 105.9000 ft 115.8465 cf 101.9000 ft 37.3065 cf 106.0000 ft 117.8100 cf 102.0000 ft 39.2700 cf 106.1000 ft 119.7735 cf 102.1000 ft 41.2335 cf 106.2000 ft 121.7370 cf 102.2000 ft 43.1970 cf 106.3000 ft 123.7005 cf 102.3000 ft 45.1605 cf 106.4000 ft 125.6640 cf 102.4000 ft 47.1240 cf 106.5000 ft 127.6275 cf 102.5000 ft 49.0875 cf 106.6000 ft 129.5910 cf 102.6000 ft 51.0510 cf 106.7000 ft 131.5545 cf 102.7000 ft 53.0145 cf 106.8000 ft 133.5180 cf 102.8000 ft 54.9780 cf 106.9000 ft 135.4815 cf 102.9000 ft 56.9415 cf 107.0000 ft 137.4450 cf 103.0000 ft 58.9050 cf 107.1000 ft 139.4085 cf 103.1000 ft 60.8685 cf 107.2000 ft 141.3720 cf 103.2000 ft 62.8320 cf 107.3000 ft 143.3355 cf 103.3000 ft 64.7955 cf 107.4000 ft 145.2990 cf 103.4000 ft 66.7590 cf 107.5000 ft 147.2625 cf 103.5000 ft 68.7225 cf 107.6000 ft 149.2260 cf 103.6000 ft 70.6860 cf 107.7000 ft 151.1895 cf 103.7000 ft 72.6495 cf 107.8000 ft 153.1530 cf 103.8000 ft 74.6130 cf 107.9000 ft 155.1165 cf 103.9000 ft 76.5765 cf 108.0000 ft 157.0800 cf 104.0000 ft 78.5400 cf 108.1000 ft 159.0435 cf Record Id: N-002 Descrip: Prototype Record Increment 0.10 ft Start El. 99.7500 ft Max El. 108.0000 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 24 - Condition Existing Stage Storage Rating Curve 99.7500 ft 0.0000 cf 103.9500 ft 82.4670 cf 99.8500 ft 1.9635 cf 104.0500 ft 84.4305 cf 99.9500 ft 3.9270 cf 104.1500 ft 86.3940 cf 100.0500 ft 5.8905 cf 104.2500 ft 88.3575 cf 100.1500 ft 7.8540 cf 104.3500 ft 90.3210 cf 100.2500 ft 9.8175 cf 104.4500 ft 92.2845 cf 100.3500 ft 11.7810 cf 104.5500 ft 94.2480 cf 100.4500 ft 13.7445 cf 104.6500 ft 96.2115 cf 100.5500 ft 15.7080 cf 104.7500 ft 98.1750 cf 100.6500 ft 17.6715 cf 104.8500 ft 100.1385 cf 100.7500 ft 19.6350 cf 104.9500 ft 102.1020 cf 100.8500 ft 21.5985 cf 105.0500 ft 104.0655 cf 100.9500 ft 23.5620 cf 105.1500 ft 106.0290 cf 101.0500 ft 25.5255 cf 105.2500 ft 107.9925 cf 101.1500 ft 27.4890 cf 105.3500 ft 109.9560 cf 101.2500 ft 29.4525 cf 105.4500 ft 111.9195 cf 101.3500 ft 31.4160 cf 105.5500 ft 113.8830 cf 101.4500 ft 33.3795 cf 105.6500 ft 115.8465 cf 101.5500 ft 35.3430 cf 105.7500 ft 117.8100 cf 101.6500 ft 37.3065 cf 105.8500 ft 119.7735 cf 101.7500 ft 39.2700 cf 105.9500 ft 121.7370 cf 101.8500 ft 41.2335 cf 106.0500 ft 123.7005 cf 101.9500 ft 43.1970 cf 106.1500 ft 125.6640 cf 102.0500 ft 45.1605 cf 106.2500 ft 127.6275 cf 102.1500 ft 47.1240 cf 106.3500 ft 129.5910 cf 102.2500 ft 49.0875 cf 106.4500 ft 131.5545 cf 102.3500 ft 51.0510 cf 106.5500 ft 133.5180 cf 102.4500 ft 53.0145 cf 106.6500 ft 135.4815 cf 102.5500 ft 54.9780 cf 106.7500 ft 137.4450 cf 102.6500 ft 56.9415 cf 106.8500 ft 139.4085 cf 102.7500 ft 58.9050 cf 106.9500 ft 141.3720 cf 102.8500 ft 60.8685 cf 107.0500 ft 143.3355 cf 102.9500 ft 62.8320 cf 107.1500 ft 145.2990 cf 103.0500 ft 64.7955 cf 107.2500 ft 147.2625 cf 103.1500 ft 66.7590 cf 107.3500 ft 149.2260 cf 103.2500 ft 68.7225 cf 107.4500 ft 151.1895 cf Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 25 - 103.3500 ft 70.6860 cf 107.5500 ft 153.1530 cf 103.4500 ft 72.6495 cf 107.6500 ft 155.1165 cf 103.5500 ft 74.6130 cf 107.7500 ft 157.0800 cf 103.6500 ft 76.5765 cf 107.8500 ft 159.0435 cf 103.7500 ft 78.5400 cf 107.9500 ft 161.0070 cf 103.8500 ft 80.5035 cf 108.0500 ft 162.9705 cf Record Id: P-001 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0120 Routing Method: Travel Time Translation Contributing Hyd DnNode N-002 UpNode N-001 Material Plastic Size 12" Diam Ent Losses Groove End w/Headwall Length 50.0000 ft Slope 0.50% Up Invert 100.0000 ft Dn Invert 99.7500 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 99.7500 ft Dn Invert 100.0000 ft Match inverts. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 26 - 7.0 Appendix A. Stormwater Pollution Prevention Plan B. Operations and Maintenance Manual C. Bond Quantities D. WWHM Report E. Spill Prevention, Control and Countermeasures Plan F. Geotechnical Report Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 27 - A. STORMWATER POLLUTION PREVENTION PLAN Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 28 - Stormwater Pollution Prevention Plan Stormwater Pollution Prevention Plan For Portage Creek â€“ Phase-I Prepared For City of Arlington 238 N. Olympic Ave Arlington, WA 98223 360.403.3500 Owner Developer Operator/Contractor Portage Creek, LLC Portage Creek, LLC To be determined 11926 127th Ave. NE 11926 127th Ave. NE Lake Stevens, WA 98258 Lake Stevens, WA 98258 Project Site Location XXX 207th Pl NE Arlington, WA 98223 Certified Erosion and Sediment Control Lead To be named by contractor SWPPP Prepared By Insight Engineering PO Box 1478 Everett, WA, 98206 425-303-9363 SWPPP Preparation Date March 30, 2016 Approximate Project Construction Dates May 1, 2016 i Stormwater Pollution Prevention Plan Contents 1.0 Introduction ...............................................................................................................................1 2.0 Site Description ........................................................................................................................3 2.1 Existing Conditions ...........................................................................................................3 2.2 Proposed Construction Activities ......................................................................................3 3.0 Construction Stormwater BMPs ...............................................................................................5 3.1 The 12 BMP Elements .......................................................................................................5 3.1.1 Element #1 â€“ Mark Clearing Limits ................................................................5 3.1.2 Element #2 â€“ Establish Construction Access...................................................5 3.1.3 Element #3 â€“ Control Flow Rates ....................................................................6 3.1.4 Element #4 â€“ Install Sediment Controls ..........................................................7 3.1.5 Element #5 â€“ Stabilize Soils ............................................................................8 3.1.6 Element #6 â€“ Protect Slopes ............................................................................9 3.1.7 Element #7 â€“ Protect Drain Inlets ..................................................................10 3.1.8 Element #8 â€“ Stabilize Channels and Outlets ................................................10 3.1.9 Element #9 â€“ Control Pollutants ....................................................................11 3.1.10 Element #10 â€“ Control Dewatering ...............................................................13 3.1.11 Element #11 â€“ Maintain BMPs ......................................................................13 3.1.12 Element #12 â€“ Manage the Project ................................................................13 3.2 Site Specific BMPs ..........................................................................................................16 3.3 Additional Advanced BMPs ............................................................................................16 4.0 Construction Phasing and BMP Implementation ...................................................................17 5.0 Pollution Prevention Team ......................................................................................................19 5.1 Roles and Responsibilities ...............................................................................................19 5.2 Team Members ................................................................................................................20 6.0 Site Inspections and Monitoring .............................................................................................21 6.1 Site Inspection .................................................................................................................21 6.1.1 Site Inspection Frequency ..............................................................................21 6.1.2 Site Inspection Documentation ......................................................................22 6.2 Stormwater Quality Monitoring ......................................................................................22 6.2.1 Turbidity ........................................................................................................22 6.2.2 pH ...................................................................................................................23 7.0 Reporting and Recordkeeping ................................................................................................24 7.1 Recordkeeping .................................................................................................................24 7.1.1 Site Log Book ................................................................................................24 7.1.2 Records Retention ..........................................................................................24 7.1.3 Access to Plans and Records..........................................................................24 ii Stormwater Pollution Prevention Plan 7.1.4 Updating the SWPPP .....................................................................................24 7.2 Reporting .........................................................................................................................25 7.2.1 Discharge Monitoring Reports .......................................................................25 7.2.2 Notification of Noncompliance......................................................................25 7.2.3 Permit Application and Changes ...................................................................26 Appendix A â€“ Site Plans .......................................................................................................277 Appendix B â€“ Construction BMPs .........................................................................................28 Appendix C â€“ Alternative BMPs ............................................................................................29 Appendix D â€“ General Permit ................................................................................................30 Appendix E â€“ Site Inspection Forms (and Site Log) ..............................................................31 Appendix F â€“ Engineering Calculations .................................................................................33 iii Stormwater Pollution Prevention Plan 1.0 Introduction This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the Construction stormwater permit requirements for the Portage Creek â€“ Phase-I project in Arlington, Washington. It is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24-ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. 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 on February 19, 2007. This SWPPP was prepared based on the requirements set forth in the Construction Stormwater General Permit and in the Stormwater Management Manual for Western Washington (SWMMWW 2005). 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 ï‚§ Section 1 â€“ INTRODUCTION. This section provides a summary description of the project, and the organization of the SWPPP document. ï‚§ 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. ï‚§ 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). ï‚§ 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. ï‚§ 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 ï‚§ 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. ï‚§ 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 2 Stormwater Pollution Prevention Plan 2.0 Site Description 2.1 Existing Conditions The proposed project Portage Creek - Phase-I is located at XXX 207th Pl NE Arlington, Washington. More generally, the site is located in Section 12, Township 31 North, and Range 5 East of the Willamette Meridian in Snohomish County, Washington. The project proposal is to develop Phase-1 of a multiple phase design of the site that contains 6.26 Acers. The clearing area for Phase-1 is 0.72 Acres. The entire site is a part of an approved plan for Portage Creek Estates (Auditors File # 9405255013) as lot 1. The existing site is currently undeveloped and exists as low growing foliage with a few trees and a man-made pond located on the northern portion of the site. The site contains one basin that slopes to the northwest into the existing pond. Per SCC survey of Snohomish County, the project site contains Norma and Pastik type soils that have a hydrologic classification of Type â€œCâ€. 2.2 Proposed Construction Activities The site is zoned RHD. The proposal for Phase-1 is to construct 6 single family homes with a 24- ft wide asphalt access way with associated utilities. The access will be provided from 207 St. NE, with a driveway entrance to be constructed per the city of Arlington standards. The existing sidewalk along 207th St. NE will remain. The existing onsite pond will provide adequate detention to the DOEâ€™s and the City of Arlingtonâ€™s requirements. The following summarizes details regarding site areas: ï‚§ Project development area: 0.72 acres ï‚§ Percent impervious area before construction: 0% ï‚§ Percent impervious area after construction: 50 % ï‚§ Disturbed area during construction: 0.72 acres ï‚§ Disturbed area that is characterized as impervious (i.e., access roads, staging, parking): 0.36 acres 3 Stormwater Pollution Prevention Plan ï‚§ 2-year stormwater runoff peak flow prior to construction (existing): 0.01 cfs ï‚§ 10-year stormwater runoff peak flow prior to construction (existing): 0.02 cfs ï‚§ 2-year stormwater runoff peak flow during construction: 0.10 cfs ï‚§ 10-year stormwater runoff peak flow during construction: 0.20 cfs ï‚§ 2-year stormwater runoff peak flow after construction: 0.13 cfs ï‚§ 10-year stormwater runoff peak flow after construction: 0.24 cfs All stormwater flow calculations are provided in Appendix F. 4 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: ï‚· Buffer Zones (BMP C102) The stream & wetland buffer will remain un-disturbed, as shown on the approved construction plans, permanently protected as a â€œNative Growth Protection Areaâ€. ï‚· High Visibility Plastic or Metal Fence (BMP C103) Install orange barrier fencing along the clearing limits, according to the approved construction plans, prior to any construction activities. Maintain until all construction activities are completed. Alternate BMPs for marking clearing limits 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. 3.1.2 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: ï‚· Stabilized Construction Entrance (BMP C105) 5 Stormwater Pollution Prevention Plan Install the temporary construction entrance, according to the approved construction plans, prior to any clearing or grading activities. Maintain until the access road is paved. Alternate construction access 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. 3.1.3 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: ï‚· Silt Fence (BMP C233) Install silt fencing, according to the approved plans, prior to any clearing or grading activities. Maintain until all construction activities are completed. ï‚· Storm Drain Inlet Protection (BMP C220) Install catch basin filters, according to the approved construction plans, as catch basins are installed and become operable. Maintain until all construction activities are completed. Alternate flow 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 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. In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements (e.g. discharge to combined sewer systems). 6 Stormwater Pollution Prevention Plan 3.1.4 Element #4 â€“ Install Sediment Controls All stormwater runoff from disturbed areas shall pass through a sediment pond during construction. The specific BMPs to be used for controlling sediment on this project also include: ï‚· Silt Fence (BMP C233) Install silt fencing, according to the approved plans, prior to any clearing or grading activities. Maintain until all construction activities are completed. ï‚· Storm Drain Inlet Protection (BMP C220) Install catch basin filters, according to the approved construction plans, as catch basins are installed and become operable. Maintain until all construction activities are completed. 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 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. 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 wash-off of sediments from adjacent streets in runoff. Whenever possible, sediment laden water shall be discharged into onsite, relatively level, vegetated areas (BMP C240 paragraph 5, page 4-102). In some cases, sediment discharge in concentrated runoff can be controlled using permanent stormwater BMPs (e.g., infiltration swales, ponds, trenches). Sediment loads can limit the effectiveness of some permanent stormwater BMPs, such as those used for infiltration or bio- filtration; however, those BMPs designed to remove solids by settling (wet ponds or detention ponds) can be used during the construction phase. When permanent stormwater BMPs will be used to control sediment discharge during construction, the structure will be protected from excessive sedimentation with adequate erosion and sediment control BMPs. Any accumulated sediment shall be removed after construction is complete and the permanent stormwater BMP will be re-stabilized with vegetation per applicable design requirements once the remainder of the site has been stabilized. 7 Stormwater Pollution Prevention Plan The following BMP will be implemented as end-of-pipe sediment controls as required to meet permitted turbidity limits in the site discharge(s). Prior to the implementation of these technologies, sediment sources and erosion control and soil stabilization BMP efforts will be maximized to reduce the need for end-of-pipe sedimentation controls. ï‚· Silt Fence (BMP C233) Install silt fencing, according to the approved plans, prior to any clearing or grading activities. Maintain until all construction activities are completed. ï‚· Storm Drain Inlet Protection (BMP C220) Install catch basin filters, according to the approved construction plans, as catch basins are installed and become operable. Maintain until all construction activities are completed. 3.1.5 Element #5 â€“ Stabilize Soils Exposed and un-worked 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: ï‚· Temporary and Permanent Seeding (BMP C120) Apply temporary hydro-seed to exposed and un-worked soils, according to the approved construction plans, as needed to prevent erosion during site grading. Apply permanent hydro-seed to areas at final grade as site grading is completed. ï‚· Mulching (BMP C121) Apply mulching to exposed and un-worked soils, according to the approved construction plans, as needed to prevent erosion during site grading. Maintain until site grading is completed and permanent hydro-seed is applied. ï‚· Plastic Covering (BMP C123) Cover stockpiles with plastic sheeting, according to the approved construction plans, as needed to prevent erosion during site grading. Maintain until stockpiles are removed from site. ï‚· Early application of gravel base on areas to be paved 8 Stormwater Pollution Prevention Plan Place gravel base on roadways, according to the approved construction plans, after roadways are graded to sub-grade. Maintain until roads are paved. Alternate soil 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. The project site is located west of the Cascade Mountain Crest. As such, no soils shall remain exposed and unworked for more than 7 days during the dry season (May 1 to September 30) and 2 days during the wet season (October 1 to April 30). Regardless of the time of year, all soils shall be stabilized at the end of the shift before a holiday or weekend if needed based on weather forecasts. 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. 3.1.6 Element #6 â€“ Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes erosion. The following specific BMPs will be used to protect slopes for this project: ï‚· Temporary and Permanent Seeding (BMP C120) Apply temporary hydro-seed to cut and fill slopes, according to the approved construction plans, as needed to minimize erosion during site grading. Apply permanent hydro-seed to cut and fill slopes at final grade as site grading is completed. Alternate slope protection 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. 9 Stormwater Pollution Prevention Plan 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: Drop Inlet Protection ï‚· Catch Basin Filters Install catch basin filters, according to the approved construction plans, as catch basins become operable. Maintain until all construction activities are completed. If the BMP options listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D), or if no BMPs are listed above but deemed necessary during construction, the Certified Erosion and Sediment Control Lead shall implement one or more of the alternative BMP inlet protection options listed in Appendix C. 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: ï‚· Outlet Protection (BMP C209) Place rip-rap pad at the temporary outfalls, according to the approved construction plans. 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. 10 Stormwater Pollution Prevention Plan The project site is located west of the Cascade Mountain Crest. As such, all temporary on-site conveyance channels shall be designed, constructed, and stabilized to prevent erosion from the expected peak 10 minute velocity of flow from a Type 1A, 10-year, 24-hour recurrence interval storm for the developed condition. Alternatively, the 10-year, 1-hour peak flow rate indicated by an approved continuous runoff simulation model, increased by a factor of 1.6, shall be used. Stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes, and downstream reaches shall be provided at the outlets of all conveyance systems. 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 housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. If required, BMPs to be implemented to control specific sources of pollutants are discussed below. Vehicles, construction equipment, and/or petroleum product storage/dispensing: ï‚§ All vehicles, equipment, and petroleum product storage/dispensing areas will be inspected regularly to detect any leaks or spills, and to identify maintenance needs to prevent leaks or spills. ï‚§ On-site fueling tanks and petroleum product storage containers shall include secondary containment. ï‚§ Spill prevention measures, such as drip pans, will be used when conducting maintenance and repair of vehicles or equipment. ï‚§ In order to perform emergency repairs on site, temporary plastic will be placed beneath and, if raining, over the vehicle. ï‚§ Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Chemical storage: ï‚§ Any chemicals stored in the construction areas will conform to the appropriate source control BMPs listed in Volume IV of the Ecology stormwater manual. In Western WA, all chemicals shall have cover, containment, and protection provided on site, per BMP C153 for Material Delivery, Storage and Containment in SWMMWW 2005 11 Stormwater Pollution Prevention Plan ï‚§ Application of agricultural chemicals, including fertilizers and pesticides, shall be conducted in a manner and at application rates that will not result in loss of chemical to stormwater runoff. Manufacturersâ€™ recommendations for application procedures and rates shall be followed. Excavation and tunneling spoils dewatering waste: ï‚§ Dewatering BMPs and BMPs specific to the excavation and tunneling (including handling of contaminated soils) are discussed under Element 10. Demolition: ï‚§ Dust released from demolished sidewalks, buildings, or structures will be controlled using Dust Control measures (BMP C140). ï‚§ Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or debris will be protected using Storm Drain Inlet Protection (BMP C220 as described above for Element 7). ï‚§ Process water and slurry resulting from saw-cutting and surfacing operations will be prevented from entering the waters of the State by implementing Saw-cutting and Surfacing Pollution Prevention measures (BMP C152). Concrete and grout: ï‚§ Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling measures (BMP C151). Sanitary wastewater: ï‚§ Portable sanitation facilities will be firmly secured, regularly maintained, and emptied when necessary. ï‚§ Wheel wash or tire bath wastewater shall be discharged to a separate on- site treatment system or to the sanitary sewer as part of Wheel Wash implementation (BMP C106). Solid Waste: ï‚§ Solid waste will be stored in secure, clearly marked containers. 12 Stormwater Pollution Prevention Plan Other: ï‚§ Other BMPs will be administered as necessary to address any additional pollutant sources on site. The facility is transportation-related and therefore not subject to the Federal requirements of the Spill Prevention, Control, and Countermeasure (SPCC) Plan under the Clean Water Act (CWA). If applicable, the Contractor shall prepare an SPCC Plan according to the Washington State Department of Transportation (WSDOT) Requirements (see the WSDOT Standard Specifications for Road, Bridge, and Municipal Construction 2004). A SPCC plan is required for this site. As per the Federal regulations of the Clean Water Act (CWA) and according to Final Rule 40 CFR Part 112, as stated in the National Register, a Spill Prevention, Control, and Countermeasure (SPCC) Plan is required for construction activities. A SPCC Plan has been prepared to address an approach to prevent, respond to, and report spills or releases to the environment that could result from construction activities. This Plan must: ï‚§ Be well thought out in accordance with good engineering; ï‚§ Achieve three objectives - prevent spills, contain a spill that occurs, and clean up the spill; ï‚§ Identify the name, location, owner, and type of facility; ï‚§ Include the date of initial operation and oil spill history; ï‚§ Name the designated person responsible; ï‚§ Show evidence of approval and certification by the person in authority; and ï‚§ Contain a facility analysis. 3.1.10 Element #10 â€“ Control Dewatering Baker tanks are proposed for dewatering. 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 13 Stormwater Pollution Prevention Plan 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. 3.1.11 Element #11 â€“ Maintain BMPs All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMPâ€™s specifications. Visual monitoring of the BMPs will be conducted at least once every calendar week and within 24 hours of any rainfall event that causes a discharge from the site. If the site becomes inactive, and is temporarily stabilized, the inspection frequency will be reduced to once every month. All temporary erosion and sediment control BMPs shall be removed within 30 days after the final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be removed or stabilized on site. Disturbed soil resulting from removal of BMPs or vegetation shall be permanently stabilized. 3.1.12 Element #12 â€“ Manage the Project Erosion and sediment control BMPs for this project have been designed based on the following principles: ï‚§ Design the project to fit the existing topography, soils, and drainage patterns. ï‚§ Emphasize erosion control rather than sediment control. ï‚§ Minimize the extent and duration of the area exposed. ï‚§ Keep runoff velocities low. ï‚§ Retain sediment on site. ï‚§ Thoroughly monitor site and maintain all ESC measures. ï‚§ Schedule major earthwork during the dry season. As this project site is located west of the Cascade Mountain Crest, the project will be managed according to the following key project components: 14 Stormwater Pollution Prevention Plan Phasing of Construction ï‚§ The construction project is being phased to the extent practicable in order to prevent soil erosion, and, to the maximum extent possible, the transport of sediment from the site during construction. ï‚§ Re-vegetation of exposed areas and maintenance of that vegetation shall be an integral part of the clearing activities during each phase of construction, per the Scheduling BMP (C 162). Seasonal Work Limitations ï‚§ From October 1 through April 30, clearing, grading, and other soil disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority that silt-laden runoff will be prevented from leaving the site through a combination of the following: ï‚¨ Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters; and ï‚¨ Limitations on activities and the extent of disturbed areas; and ï‚¨ Proposed erosion and sediment control measures. ï‚§ Based on the information provided and/or local weather conditions, the local permitting authority may expand or restrict the seasonal limitation on site disturbance. ï‚§ The following activities are exempt from the seasonal clearing and grading limitations: ï‚¨ Routine maintenance and necessary repair of erosion and sediment control BMPs; ï‚¨ Routine maintenance of public facilities or existing utility structures that do not expose the soil or result in the removal of the vegetative cover to soil; and ï‚¨ Activities where there is 100 percent infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. 15 Stormwater Pollution Prevention Plan Coordination with Utilities and Other Jurisdictions ï‚§ Care has been taken to coordinate with utilities, other construction projects, and the local jurisdiction in preparing this SWPPP and scheduling the construction work. Inspection and Monitoring ï‚§ All BMPs shall be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections shall be conducted by a person who is knowledgeable in the principles and practices of erosion and sediment control. This person has the necessary skills to: ï‚¨ Assess the site conditions and construction activities that could impact the quality of stormwater, and ï‚¨ Assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. ï‚§ A Certified Erosion and Sediment Control Lead shall be on-site or on-call at all times. ï‚§ Whenever inspection and/or monitoring reveals that the BMPs identified in this SWPPP are inadequate, due to the actual discharge of or potential to discharge a significant amount of any pollutant, appropriate BMPs or design changes shall be implemented as soon as possible. Maintaining an Updated Construction SWPPP ï‚§ This SWPPP shall be retained on-site or within reasonable access to the site. ï‚§ The SWPPP shall be modified whenever there is a change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the state. ï‚§ The SWPPP shall be modified if, during inspections or investigations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems 16 Stormwater Pollution Prevention Plan identified. Revisions to the SWPPP shall be completed within seven (7) days following the inspection. 3.2 Site Specific BMPs Site specific BMPs are shown on the TESC Plan Sheets and Details in Appendix A. These site specific plan sheets will be updated annually. 3.3 Additional Advanced BMPs 17 Stormwater Pollution Prevention Plan 4.0 Construction Phasing and BMP Implementation The BMP implementation schedule will be 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. The 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. ï‚· Estimate of Construction start date: May 1, 2016 ï‚· Estimate of Construction finish date: July 10 ,2016 ï‚· Dry Season begins: May 1, 2016 Site inspections and monitoring conducted weekly and for applicable rain events as detailed in Section 6 of this SWPPP. Implement Element #12 BMPs and manage site to minimize soil disturbance during the wet season. ï‚· Mobilize equipment on site May 1, 2016 ï‚· Mobilize and store all ESC and soil stabilization products May 1, 2016 ï‚· Install ESC measures: May 1, 2016 ï‚· Install stabilized construction entrance: May 1, 2016 ï‚· Begin clearing and grubbing: May 15, 2016 ï‚· Site grading begins: May 25, 2016 ï‚· Grade road and stabilize with gravel base May 25, 2016 ï‚· Begin excavation for new utilities and services June 1, 2016 ï‚· Soil stabilization on excavated side slopes (in idle, no work areas) June 5, 2016 ï‚· Temporary erosion control measures (hydro-seeding) June 1, 2016 ï‚· Site grading ends: May 15, 2016 ï‚· Begin pouring concrete curbs & sidewalks and implement BMP C151: June 1, 2016 ï‚· Pave asphalt roads June 5, 2016 ï‚· Implement Element #12 BMPs and manage site to minimize soil disturbance during the wet season: July 11, 2016 19 Stormwater Pollution Prevention Plan ï‚· Final landscaping and planting begins: May 15, 2016 ï‚· Permanent erosion control measures (hydro-seeding): June 1, 2016 ï‚· Wet Season Begins: Oct 1, 2016 20 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: ï‚§ 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. ï‚§ 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 supervising engineer responsible for inspections and issuing instructions and drawings to the contractor's site supervisor or representative ï‚§ Emergency Ecology Contact â€“ individual to be contacted at Ecology in case of emergency. ï‚§ Emergency Owner Contact â€“ individual that is the site owner or representative of the site owner to be contacted in the case of an emergency. ï‚§ Non-Emergency Ecology Contact â€“ individual that is the site owner or representative of the site owner than can be contacted if required. ï‚§ Monitoring Personnel â€“ personnel responsible for conducting water quality monitoring; for most sites this person is also the Certified Erosion and Sediment Control Lead. 21 Stormwater Pollution Prevention Plan 5.2 Team Members Names and contact information for those identified as additional members of the pollution prevention team are provided in the following table. Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) Brian Kalab 425-303-9363 Resident Engineer Brian Kalab / Insight Engineering 425-303-9363 Emergency Ecology Contact Tracy Walters 425-649-7000 Emergency Owner Contact Randy Brockway 206-992-5051 Non-Emergency Ecology Contact Tracy Walters 425-649-7000 Monitoring Personnel Tony Veslic 253-271-7870 22 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: ï‚§ A record of the implementation of the SWPPP and other permit requirements; ï‚§ Site inspections; and, ï‚§ 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. 23 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 Ecology or the local jurisdiction. 6.2 Stormwater Quality Monitoring 6.2.1 Turbidity Sampling Monitoring requirements for the proposed project will include either turbidity or water transparency sampling to monitor site discharges for water quality compliance with the 2005 Construction Stormwater General Permit (Appendix D). Sampling will be conducted at all discharge points at least once per calendar week. Turbidity or transparency monitoring will follow the analytical methodologies described in Section S4 of the 2005 Construction Stormwater General Permit (Appendix D). The key benchmark values that require action are 25 NTU for turbidity (equivalent to 32 cm transparency) and 250 NTU for turbidity (equivalent to 6 cm transparency). If the 25 NTU benchmark for turbidity (equivalent to 32 cm transparency) is exceeded, 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 revisions to the SWPPP as necessary. 3. Sample discharge location daily until the analysis results are less than 25 NTU (turbidity) or greater than 32 cm (transparency). If the turbidity is greater than 25 NTU (or transparency is less than 32 cm) but less than 250 NTU (transparency greater than 6 cm) for more than 3 days, additional treatment BMPs will be implemented within 24 hours of the third consecutive sample that exceeded the benchmark value. Additional treatment BMPs to be considered will include, but are not limited to, off-site treatment, infiltration, filtration and chemical treatment. If the 250 NTU benchmark for turbidity (or less than 6 cm transparency) is exceeded 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). 24 Stormwater Pollution Prevention Plan 2. Continue daily sampling until the turbidity is less than 25 NTU (or transparency is greater than 32 cm). 3. Initiate additional treatment BMPs such as off-site treatment, infiltration, filtration and chemical treatment within 24 hours of the first 250 NTU exceedance. 4. Implement additional treatment BMPs as soon as possible, but within 7 days of the first 250 NTU exceedance. 5. 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 Stormwater runoff will be monitored for pH starting on the first day of any activity that includes more than 40 yards of poured or recycled concrete, or after the application of â€œEngineered Soilsâ€ such as, Portland cement treated base, cement kiln dust, or fly ash. This does not include fertilizers. For concrete work, pH monitoring will start the first day concrete is poured and continue until 3 weeks after the last pour. For engineered soils, the pH monitoring period begins when engineered soils are first exposed to precipitation and continue until the area is fully stabilized. Stormwater samples will be collected daily from all points of discharge from the site and measured for pH using a calibrated pH meter, pH test kit, or wide range pH indicator paper. If the measured pH is 8.5 or greater, the following steps will be conducted: 1. Prevent the high pH water from entering storm drains or surface water. 2. Adjust or neutralize the high pH water if necessary using appropriate technology such as CO2 sparging (liquid or dry ice). 3. Contact Ecology if chemical treatment other than CO2 sparging is planned. 25 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: ï‚§ A record of the implementation of the SWPPP and other permit requirements; ï‚§ Site inspections; and, ï‚§ 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, General Permit, Notice of Authorization letter, 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 Ecology or the local jurisdiction. A copy of this SWPPP will be provided to Ecology within 14 days of receipt of a written request for the SWPPP from Ecology. Any other information requested by Ecology 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 in accordance with permit condition S5.G. 7.1.4 Updating the SWPPP In accordance with Conditions S3, S4.B, and S9.B.3 of the General Permit, this SWPPP will be modified if the SWPPP is ineffective in eliminating or significantly minimizing 26 Stormwater Pollution Prevention Plan pollutants in stormwater discharges from the site or there has been a change in 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 Water quality sampling results will be submitted to Ecology monthly on Discharge Monitoring Report (DMR) forms in accordance with permit condition S5.B. If there was no discharge during a given monitoring period, the form will be submitted with the words â€œno dischargeâ€ entered in place of the monitoring results. If a benchmark was exceeded, a brief summary of inspection results and remedial actions taken will be included. If sampling could not be performed during a monitoring period, a DMR will be submitted with an explanation of why sampling could not be performed. 7.2.2 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 in accordance with permit section S5.F: 1. Ecology 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 Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. 7.2.3 Permit Application and Changes In accordance with permit condition S2.A, a complete application form will be submitted to Ecology and the appropriate local jurisdiction (if applicable) to be covered by the General Permit. Appendix A â€“ Site Plans 27 Stormwater Pollution Prevention Plan Appendix B â€“ Construction BMPs Element #1 - Mark Clearing Limits High Visibility Plastic or Metal Fence (BMP C103) Element #2 - Establish Construction Access Stabilized Construction Entrance (BMP C105) Element #3 - Control Flow Rates Sediment Pond Element #4 - Install Sediment Controls Silt Fence (BMP C233) Storm Drain Inlet Protection (BMP C220) Interceptor Dike and Swale (BMP C200) Element #5 - Stabilize Soils Mulching (BMP C121) Temporary and Permanent Seeding (BMP C120) Element #6 - Protect Slopes Plastic Covering (BMP C123) Element #7 â€“ Protect Drain Inlets Storm Drain Inlet Protection (BMP C220) Element #8 - Stabilize Channels and Outlets Outlet Protection (BMP C209) 28 Stormwater Pollution Prevention Plan 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 housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well-organized, and free of debris. Element #10 - Control Dewatering There will be no dewatering expected as part of this proposal. If it occurs, Baker tanks will be used for dewatering. Element #11 â€“ Maintain BMPâ€™s Scheduling (BMP C162) Element #12 â€“ Manage the Project CESC Lead (BMP C160) 29 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 #1 - Mark Clearing Limits Preserving Natural Vegetation (C101) Element #2 - Establish Construction Access Wheel Wash (C106) Construction Road/Parking area stabilization (BMP C107) Element #3 - Control Flow Rates Temporary Sediment Pond (BMP C241) Sediment Trap (BMP C240) Element #4 - Install Sediment Controls Triangular Silt Dike (BMP C208) Element #5 - Stabilize Soils Surface roughening (BMP C130) Element #6 - Protect Slopes Nets and Blankets (BMP C122) Element #7 â€“ Protect Drain Inlets Element #8 - Stabilize Channels and Outlets Channel Lining (BMP C202) Element #9 â€“ Control Pollutants Element #10 - Control Dewatering Element #11 â€“ Maintain BMPâ€™s Element #12 â€“ Manage the Project 30 Stormwater Pollution Prevention Plan Appendix D â€“ General Permit 31 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. 32 Stormwater Pollution Prevention Plan h. A statement that, in the judgment of the person conducting the site inspection, the site is either in compliance or out of compliance 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. 33 Stormwater Pollution Prevention Plan Appendix F â€“ Engineering Calculations See Drainage Report dated 2-1-16 34 B. OPERATION AND MAINTENANCE MANUAL The facilities that require periodic maintenance for this project are as follows. o Detention Ponds o Catch basins o Debris Barriers o Energy Dissipaters o Filter Strips o Catch basin Inserts Refer to the following pages for facilities that require maintenance. Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 29 - C. BOND QUANTITIES Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 30 - CITY OF ARLINGTON INSTRUCTIONS FOR ENGINEER COST ESTIMATE & BOND QUANTITY WORKSHEET 1) Based on permit type requested (Grading, Site Civil Construction, etc.), complete the form as follows: - For Grading permits, complete the Erosion Control section - For Site Civil Construction permits, complete the Erosion Control and General sections 2) Complete the 'Quantity' columns for the appropriate section(s). If you are completing the 'General' section, you will be asked to identify those quantities and costs that apply to Existing Right-of-Way, Future Public Improvements and Private Improvements. 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 Public Works fees due at intake for Grading and Site Civil construction permits only. This does not include fees required by other departments. 5) Per Resolution #772, all cost data for the engineers cost estimate is from the RS Means (latest edition) adjusted for the Snohomish County area or from local sources if not included in the RS Means. 6) Signed Professional Engineer stamp is required on all engineer cost estimates. 7) If an item that is part of your project does not exist in the spreadsheet complete the Write-In-Items section with the item and associated cost. BOND QUANTITY ESTIMATE & ENGINEERS COST ESTIMATE SUMMARY Prepared By Project Information Name: Brian r. Kalab, PE Project Name: Portage Creek - Phase - I Date: PE Registration No: 36499 Project No: Firm Name: Insight Engineering Project Address: XXX Firm Address: PO Box 1478 Arlington, WA 98223 Phone No. 425-303-9363 Grading Quantities: 100 Email Address: brian@insightengineering.net (Cut / Fill) 1,338/1,438 CONSTRUCTION BOND AMOUNT MAINTENANCE BOND BOND WORKSHEET PE STAMP & SIGNATURE (prior to permit issuance) (after final acceptance of construction) Site Restoration/TESC Total (A) $ 17,573.38 (A) $ 17,573.38 Existing Right-of-Way Improvements Total (B) $ 19,482.84 (B) $ 19,482.84 Future Public Improvements Total (C) $ - (C) $ - Private Improvements Total (D) $ 63,206.29 (D) $ 63,206.29 TOTAL SITE CIVIL CONSTRUCTION COST $ 100,262.51 Site Restoration TESC Bond (A) x 150% $ 26,360.07 Site Civil Construction Surety Bond (A) + (B) + $ 55,584.33 (C) x 150% Maintenance Bond (B) + (C) x 20% $ 3,896.57 City of Arlington - 2009 Engineer Cost Estimate and Bond Quantity Worksheet Updated 4/19/2016 City of Arlington Engineer's Cost Estimate (A) Unit Reference # Price Unit Quantity Cost TEMPORARY EROSION & SEDIMENT CONTROL Backfill & compaction-embankment $6.50 CY Check dams BMP C207 $78.00 Each Catch Basin Protection $35.50 Each 1 35.50 Crushed surfacing 1 1/4" minus WSDOT 9-03.9(3) $98.00 CY Ditching $8.00 CY Excavation-bulk $3.00 CY 500 1500.00 Fence, silt BMP C233 $2.00 LF 500 1000.00 Fence, Temporary (NGPA) $2.00 LF Geotextile Fabric $2.50 SY Hay Bale Silt Trap $0.50 Each Hydroseeding BMP C120 $1.00 SY Interceptor Swale / Dike $1.00 LF Jute Mesh BMP C122 $2.00 SY Level Spreader $1.75 LF Mulch, by hand, straw, 3" deep BMP C121 $3.00 SY 1000 3000.00 Mulch, by machine, straw, 2" deep BMP C121 $1.00 SY 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 BMP C123 $3.00 SY Rip Rap, machine placed; slopes WSDOT 9-13.1(2) $50.00 CY Rock Construction Entrance, 50'x15'x1' BMP C105 $1,800.00 Each Rock Construction Entrance, 100'x15'x1' BMP C105 $3,600.00 Each 1 3600.00 Sediment pond riser assembly BMP C241 $3,050.00 Each Sediment trap, 5' high berm BMP C240 $21.00 LF Sed. trap, 5' high, riprapped spillway berm section BMP C240 $79.00 LF Seeding, by hand BMP C120 $1.00 SY Sodding, 1" deep, level ground BMP C120 $8.00 SY 200 1600.00 Sodding, 1" deep, sloped ground BMP C120 $9.50 SY TESC Supervisor $84.00 HR 8 672.00 Water truck, dust control BMP C140 $130.00 HR 8 1040.00 WRITE-IN-ITEMS EROSION/SEDIMENT SUBTOTAL: $ 12,447.50 30% CONTINGENCY & MOBILIZATION: $ 3,734.25 SALES TAX @ 8.6% $ 1,391.63 EROSION/SEDIMENT TOTAL: $ 17,573.38 (A) City of Arlington - 2009 Engineer's Cost Estimate Bond Quantity Worksheet Page 1 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-Way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost GENERAL ITEMS Backfill & Compaction- embankment $ 8.00 CY Backfill & Compaction- trench $ 11.00 CY 80 880.00 Clear/Remove Brush, by hand (acre) $ 2,363.00 Acre Bollards - fixed $ 325.00 Each Bollards - removable $ 600.00 Each Clearing/Grubbing/Tree Removal $ 6,000.00 Acre 0.72 4,320.00 Excavation - bulk $ 2.50 CY 1000 2,500.00 Excavation - Trench $ 5.00 CY 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 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 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, rockery $ 13.00 SF SUBTOTAL 7,700.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 2 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost STREET IMPROVEMENT 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 Barricade, Type I $ 36.00 LF Barricade Type II $ 25.00 LF Barricade, Type III ( Permanent ) $ 55.00 LF Conduit, 2" $ 5.00 LF Curb & Gutter, rolled $ 20.00 LF Curb & Gutter, vertical $ 15.00 LF 30 450.00 Curb and Gutter, demolition and disposal $ 20.00 LF 60 1,200.00 Curb, extruded asphalt $ 5.00 LF Curb, extruded concrete $ 4.50 LF Guard Rail $ 30.00 LF Sawcut, asphalt, 3" depth $ 3.50 LF Sawcut, concrete, per 1" depth $ 3.00 LF Sealant, asphalt $ 2.00 LF Shoulder, gravel, 4" thick $ 11.00 SY Sidewalk, 4" thick $ 40.00 SY 30 1,200.00 Sidewalk, 4" thick, demolition and disposal $ 36.00 SY 30 1,080.00 Sidewalk, 6" thick $ 45.00 SY Sidewalk, 6" thick, demolition and disposal $ 45.00 SY Signs LS Sign, Handicap $ 100.00 Each Striping, per stall $ 7.50 Each Street Light System LS Traffic Signal LS Traffic Signal Modification LS Striping, thermoplastic, ( for crosswalk ) $ 3.50 SF Striping, 4" reflectorized line $ 0.40 LF SUBTOTAL 3,930.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 3 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost STREET SURFACING/PAVEMENT Asphalt Overlay, 1.5" AC $ 12.00 SY Asphalt Overlay, 2" AC $ 15.00 SY Asphalt Road 2", First 2500 SY $ 10.00 SY Asphalt Road 2", Qty. over 2500SY $ 9.00 SY Asphalt Road 3", First 2500 SY $ 15.00 SY 80 1,200.00 400 6,000.00 Asphalt Road 3", Qty. over 2500 SY $ 13.00 SY 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 80 600.00 400 3,000.00 Gravel Base Course 4" $ 15.00 SY Gravel Base Course 6" $ 22.50 SY 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 SUBTOTAL 1,800.00 9,000.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 4 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost DRAINAGE Access Road, Retention / Detention $ 26.00 SY * (CBs include frame and lid) Beehive $ 90.00 Each CB Type I $ 1,650.00 Each 1 1,650.00 CB Type IL $ 1,850.00 Each CB Type II, 48" diameter $ 2,550.00 Each for additional depth over 4' $ 650.00 FT CB Type II, 54" diameter $ 2,700.00 Each for additional depth over 4' $ 600.00 FT CB Type II, 60" diameter $ 2,900.00 Each for additional depth over 4' $ 750.00 FT CB Type II, 72" diameter $ 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 Cleanout, PVC, 8" $ 300.00 Each 6 1,800.00 Culvert, Box __ ft x __ ft LS Culvert, PVC, 4" $ 12.00 LF Culvert, PVC, 6" $ 17.00 LF 250 4,250.00 Culvert, PVC, 8" $ 19.00 LF Culvert, PVC, 12" $ 30.00 LF 80 2,400.00 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, Concrete, 8" 36.00 LF SUBTOTAL 10,100.00 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 5 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost DRAINAGE (CONTINUED) Culvert, Concrete, 12" $ 43.00 LF 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 Culvert, CPP, 12" $ 28.00 LF Culvert, CPP, 15" $ 34.00 LF Culvert, CPP, 18" $ 39.00 LF 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) - Infiltration trench $ 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 10 520.00 Tank End Reducer (36" diameter) $ 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 SUBTOTAL 520 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 6 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost WATER SYSTEM Blowoff $ 1,800.00 Each Connection to Existing Water Main $ 2,000.00 Each 6 12000 Ductile Iron Watermain, CL 52, 6 Inch Diameter $ 65.00 LF Ductile Iron Watermain, CL 52, 8 Inch Diameter $ 85.00 LF Ductile Iron Watermain, CL 52, 10 Inch Diameter $ 103.00 LF Ductile Iron Watermain, CL 52, 12 Inch Diameter $ 125.00 LF Gate Valve, 6 inch Diameter $ 250.00 Each Gate Valve, 8 Inch Diameter $ 380.00 Each Gate Valve, 10 Inch Diameter $ 425.00 Each Gate Valve, 12 Inch Diameter $ 500.00 Each Fire Hydrant Assembly, with Guard Posts $ 3,000.00 Each Fire Hydrant Assembly, without Guard Posts $ 2,500.00 Each Air-Vac, 8 Inch Diameter $ 6,000.00 Each Air-Vac,10 Inch Diameter $ 7,500.00 Each Air-Vac, 12 Inch Diameter $ 12,000.00 Each Pressure Reducing Valve Assembly, 8 In. Diam. $ 3,800.00 Each Pressure Reducing Valve Assembly, 10 In. Diam. $ 4,200.00 Each Pressure Reducing Valve Assembly, 12 In. Diam. $ 5,000.00 Each Valve Marker Post $ 350.00 Each SUBTOTAL 12000 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 7 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost SANITARY SEWER Clean Outs $ 500.00 Each 2 1000 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 Diameter $ 8.00 LF Side Sewer Pipe, PVC. 6 Inch Diameter $ 12.00 LF 210 2520 Sewer Pipe, PVC, 8 inch Diameter $ 33.00 LF Sewer Pipe, PVC, 12 Inch Diameter $ 41.00 LF Sewer Pipe, PVC, ____ Inch Diameter LF Lift Station (Entire System) LS Manhole, 48 Inch Diameter $ 3,000.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 54 Inch Diameter $ 3,500.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 60 Inch Diameter $ 3,700.00 Each for additional depth over 4 feet/per foot $ 532.00 FEET Manhole, 72 Inch Diameter $ 4,000.00 Each for additional depth over 4 feet/per foot $ 625.00 FEET Manhole, 96 Inch Diameter $ 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 SUBTOTAL 3520 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 8 of 9 Updated 4/19/2016 City of Arlington Engineer's Cost Estimate Existing Future Public Private Right-of-way Improvements Improvements (B) (C) (D) Unit Price Unit Quant. Cost Quant. Cost Quant. Cost PARKING LOT SURFACING 2" Asphalt & 4" CSTC $ 28.00 SY LANDSCAPING & VEGETATION Street Trees $ 500.00 Each 20 10000 Median Landscaping LS Right-of-Way Landscaping LS Wetland Landscaping LS WRITE-IN-ITEMS (Such as detention/water quality vaults.) SUBTOTAL 10,000.00 SUBTOTAL (SUM ALL PAGES): 13,800.00 44,770.00 30% CONTINGENCY & MOBILIZATION: 4,140.00 13,431.00 SALES TAX @ 8.6% 1,542.84 5,005.29 GRANDTOTAL: 19,482.84 63,206.29 (B) (C) (D) City of Arlington -2009 Engineer's Cost Estimate Bond Quantity Worksheet 9 of 9 Updated 4/19/2016 D. WWHM REPORT Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 31 - WWHM2012 PROJECT REPORT General Model Information Project Name: Portage Creek Ex pond Recalc Site Name: Portage Creek Site Address: XXX Arlington WA City: Arlington Report Date: 4/1/2016 Gage: Everett Data Start: 1948/10/01 Data End: 2009/09/30 Timestep: 15 Minute Precip Scale: 1.20 Version Date: 2015/11/13 Version: 4.2.11 POC Thresholds Low Flow Threshold for POC1: 50 Percent of the 2 Year High Flow Threshold for POC1: 50 Year Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 2 Landuse Basin Data Predeveloped Land Use Ex Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Flat 12.11 Pervious Total 12.11 Impervious Land Use acre ROADS FLAT 0.81 SIDEWALKS FLAT 0.11 POND 1.51 Impervious Total 2.43 Basin Total 14.54 Element Flows To: Surface Interflow Groundwater Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 3 Mitigated Land Use Dv Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Flat 10.22 C, Lawn, Flat 0.94 Pervious Total 11.16 Impervious Land Use acre ROADS FLAT 1.03 ROOF TOPS FLAT 0.56 DRIVEWAYS FLAT 0.17 SIDEWALKS FLAT 0.11 POND 1.51 Impervious Total 3.38 Basin Total 14.54 Element Flows To: Surface Interflow Groundwater Additional Pond StorageAdditional Pond Storage Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 4 Routing Elements Predeveloped Routing Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 5 Mitigated Routing Additional Pond Storage Depth: 1.71 ft. Discharge Structure Riser Height: 1.71 ft. Riser Diameter: 29 in. Notch Type: Rectangular Notch Width: 2.400 ft. Notch Height: 0.500 ft. Element Flows To: Outlet 1 Outlet 2 Irregular Pond Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 138.00 1.723 0.000 0.000 0.000 138.02 1.719 0.032 0.000 0.000 138.04 1.715 0.065 0.000 0.000 138.06 1.712 0.097 0.000 0.000 138.08 1.708 0.130 0.000 0.000 138.10 1.704 0.162 0.000 0.000 138.11 1.700 0.195 0.000 0.000 138.13 1.697 0.227 0.000 0.000 138.15 1.693 0.259 0.000 0.000 138.17 1.689 0.291 0.000 0.000 138.19 1.686 0.323 0.000 0.000 138.21 1.682 0.355 0.000 0.000 138.23 1.678 0.387 0.000 0.000 138.25 1.674 0.419 0.000 0.000 138.27 1.671 0.451 0.000 0.000 138.29 1.667 0.482 0.000 0.000 138.30 1.663 0.514 0.000 0.000 138.32 1.660 0.545 0.000 0.000 138.34 1.656 0.577 0.000 0.000 138.36 1.652 0.608 0.000 0.000 138.38 1.649 0.640 0.000 0.000 138.40 1.645 0.671 0.000 0.000 138.42 1.641 0.702 0.000 0.000 138.44 1.638 0.733 0.000 0.000 138.46 1.634 0.764 0.000 0.000 138.48 1.630 0.795 0.000 0.000 138.49 1.627 0.826 0.000 0.000 138.51 1.623 0.857 0.000 0.000 138.53 1.619 0.888 0.000 0.000 138.55 1.616 0.918 0.000 0.000 138.57 1.612 0.949 0.000 0.000 138.59 1.608 0.980 0.000 0.000 138.61 1.605 1.010 0.000 0.000 138.63 1.601 1.041 0.000 0.000 138.65 1.597 1.071 0.000 0.000 138.67 1.594 1.101 0.000 0.000 138.68 1.590 1.131 0.000 0.000 138.70 1.586 1.162 0.000 0.000 138.72 1.583 1.192 0.000 0.000 138.74 1.579 1.222 0.000 0.000 Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 6 138.76 1.575 1.252 0.000 0.000 138.78 1.572 1.281 0.000 0.000 138.80 1.568 1.311 0.000 0.000 138.82 1.565 1.341 0.000 0.000 138.84 1.561 1.371 0.000 0.000 138.86 1.557 1.400 0.000 0.000 138.87 1.554 1.430 0.000 0.000 138.89 1.550 1.459 0.000 0.000 138.91 1.547 1.489 0.000 0.000 138.93 1.543 1.518 0.000 0.000 138.95 1.539 1.547 0.000 0.000 138.97 1.536 1.576 0.000 0.000 138.99 1.532 1.606 0.000 0.000 139.01 1.529 1.635 0.000 0.000 139.03 1.525 1.664 0.000 0.000 139.05 1.521 1.692 0.000 0.000 139.06 1.518 1.721 0.000 0.000 139.08 1.514 1.750 0.000 0.000 139.10 1.511 1.779 0.000 0.000 139.12 1.507 1.807 0.000 0.000 139.14 1.504 1.836 0.000 0.000 139.16 1.500 1.865 0.000 0.000 139.18 1.496 1.893 0.000 0.000 139.20 1.493 1.921 0.000 0.000 139.22 1.489 1.950 0.003 0.000 139.24 1.486 1.978 0.031 0.000 139.25 1.482 2.006 0.073 0.000 139.27 1.479 2.034 0.126 0.000 139.29 1.475 2.062 0.187 0.000 139.31 1.472 2.090 0.256 0.000 139.33 1.468 2.118 0.332 0.000 139.35 1.465 2.146 0.414 0.000 139.37 1.461 2.174 0.501 0.000 139.39 1.458 2.201 0.595 0.000 139.41 1.454 2.229 0.693 0.000 139.43 1.451 2.257 0.796 0.000 139.44 1.447 2.284 0.904 0.000 139.46 1.444 2.312 1.017 0.000 139.48 1.440 2.339 1.133 0.000 139.50 1.437 2.366 1.254 0.000 139.52 1.433 2.393 1.379 0.000 139.54 1.430 2.421 1.508 0.000 139.56 1.426 2.448 1.640 0.000 139.58 1.423 2.475 1.776 0.000 139.60 1.419 2.502 1.916 0.000 139.62 1.416 2.529 2.059 0.000 139.63 1.412 2.555 2.206 0.000 139.65 1.409 2.582 2.356 0.000 139.67 1.405 2.609 2.509 0.000 139.69 1.402 2.636 2.666 0.000 139.71 1.398 2.662 2.825 0.000 Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 12.11 Total Impervious Area: 2.43 Mitigated Landuse Totals for POC #1 Total Pervious Area: 11.16 Total Impervious Area: 3.38 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 1.516944 5 year 2.109568 10 year 2.552211 25 year 3.171481 50 year 3.678219 100 year 4.225488 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.713636 5 year 0.952544 10 year 1.128971 25 year 1.373552 50 year 1.572121 100 year 1.78528 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 1.791 0.623 1950 1.902 0.743 1951 1.606 0.650 1952 1.380 0.622 1953 1.768 0.494 1954 3.288 0.686 1955 1.801 1.068 1956 1.033 0.768 1957 1.699 1.010 1958 3.325 1.077 Portage Creek Ex pond Recalc 4/1/2016 11:47:31 AM Page 8 1959 1.310 0.800 1960 1.498 0.827 1961 4.437 1.078 1962 1.488 0.743 1963 2.189 0.816 1964 1.102 0.754 1965 1.139 0.580 1966 1.142 0.472 1967 2.518 0.845 1968 1.487 1.043 1969 3.824 0.649 1970 1.118 0.569 1971 1.643 0.735 1972 1.944 1.022 1973 1.638 0.553 1974 2.016 0.654 1975 1.690 0.603 1976 1.064 0.656 1977 1.025 0.550 1978 1.031 0.573 1979 2.370 1.218 1980 1.248 0.689 1981 1.126 0.542 1982 1.069 0.902 1983 1.627 0.614 1984 1.355 0.710 1985 1.782 0.904 1986 2.541 1.579 1987 1.549 0.920 1988 1.370 0.602 1989 1.506 0.471 1990 1.143 0.663 1991 1.247 0.655 1992 1.420 0.617 1993 1.114 0.523 1994 1.093 0.554 1995 0.924 0.728 1996 1.758 1.131 1997 2.757 2.034 1998 1.727 0.623 1999 0.984 0.587 2000 2.687 0.514 2001 0.914 0.393 2002 0.886 0.656 2003 1.203 0.486 2004 2.273 0.857 2005 1.104 0.698 2006 2.184 1.126 2007 1.991 0.911 2008 1.625 1.656 2009 1.201 0.702 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 4.4371 2.0335 2 3.8236 1.6560 3 3.3248 1.5789 Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 9 4 3.2878 1.2185 5 2.7574 1.1310 6 2.6870 1.1257 7 2.5405 1.0785 8 2.5183 1.0770 9 2.3695 1.0679 10 2.2726 1.0435 11 2.1886 1.0221 12 2.1838 1.0099 13 2.0164 0.9205 14 1.9908 0.9111 15 1.9445 0.9038 16 1.9016 0.9022 17 1.8011 0.8565 18 1.7907 0.8453 19 1.7818 0.8269 20 1.7679 0.8156 21 1.7581 0.7999 22 1.7269 0.7682 23 1.6989 0.7543 24 1.6903 0.7428 25 1.6426 0.7427 26 1.6378 0.7352 27 1.6273 0.7282 28 1.6247 0.7099 29 1.6058 0.7022 30 1.5487 0.6982 31 1.5058 0.6889 32 1.4978 0.6859 33 1.4879 0.6626 34 1.4873 0.6559 35 1.4203 0.6558 36 1.3804 0.6550 37 1.3696 0.6542 38 1.3547 0.6501 39 1.3096 0.6489 40 1.2480 0.6233 41 1.2473 0.6227 42 1.2028 0.6222 43 1.2007 0.6173 44 1.1435 0.6139 45 1.1415 0.6028 46 1.1389 0.6018 47 1.1256 0.5870 48 1.1175 0.5798 49 1.1141 0.5730 50 1.1037 0.5685 51 1.1019 0.5537 52 1.0928 0.5528 53 1.0695 0.5502 54 1.0641 0.5419 55 1.0328 0.5234 56 1.0313 0.5139 57 1.0253 0.4942 58 0.9836 0.4860 59 0.9244 0.4721 60 0.9137 0.4714 61 0.8864 0.3929 Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 10 Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 11 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.7585 1813 921 50 Pass 0.7880 1566 809 51 Pass 0.8175 1369 674 49 Pass 0.8469 1195 588 49 Pass 0.8764 1058 528 49 Pass 0.9059 955 475 49 Pass 0.9354 854 436 51 Pass 0.9649 763 403 52 Pass 0.9944 695 363 52 Pass 1.0239 634 320 50 Pass 1.0534 581 289 49 Pass 1.0829 540 259 47 Pass 1.1124 470 247 52 Pass 1.1419 420 231 55 Pass 1.1714 382 223 58 Pass 1.2009 353 208 58 Pass 1.2304 318 196 61 Pass 1.2598 281 191 67 Pass 1.2893 264 183 69 Pass 1.3188 238 169 71 Pass 1.3483 224 147 65 Pass 1.3778 204 130 63 Pass 1.4073 174 112 64 Pass 1.4368 159 97 61 Pass 1.4663 148 88 59 Pass 1.4958 132 78 59 Pass 1.5253 121 67 55 Pass 1.5548 106 57 53 Pass 1.5843 97 40 41 Pass 1.6138 88 32 36 Pass 1.6432 78 23 29 Pass 1.6727 73 17 23 Pass 1.7022 65 15 23 Pass 1.7317 60 10 16 Pass 1.7612 53 8 15 Pass 1.7907 49 6 12 Pass 1.8202 42 6 14 Pass 1.8497 37 5 13 Pass 1.8792 35 5 14 Pass 1.9087 33 5 15 Pass 1.9382 30 4 13 Pass 1.9677 29 3 10 Pass 1.9972 26 2 7 Pass 2.0266 24 1 4 Pass 2.0561 23 0 0 Pass 2.0856 23 0 0 Pass 2.1151 21 0 0 Pass 2.1446 20 0 0 Pass 2.1741 18 0 0 Pass 2.2036 15 0 0 Pass 2.2331 14 0 0 Pass 2.2626 14 0 0 Pass 2.2921 13 0 0 Pass Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 12 2.3216 12 0 0 Pass 2.3511 12 0 0 Pass 2.3806 10 0 0 Pass 2.4100 10 0 0 Pass 2.4395 10 0 0 Pass 2.4690 10 0 0 Pass 2.4985 10 0 0 Pass 2.5280 8 0 0 Pass 2.5575 7 0 0 Pass 2.5870 7 0 0 Pass 2.6165 7 0 0 Pass 2.6460 7 0 0 Pass 2.6755 7 0 0 Pass 2.7050 6 0 0 Pass 2.7345 6 0 0 Pass 2.7640 5 0 0 Pass 2.7934 5 0 0 Pass 2.8229 5 0 0 Pass 2.8524 5 0 0 Pass 2.8819 5 0 0 Pass 2.9114 5 0 0 Pass 2.9409 5 0 0 Pass 2.9704 5 0 0 Pass 2.9999 5 0 0 Pass 3.0294 5 0 0 Pass 3.0589 5 0 0 Pass 3.0884 5 0 0 Pass 3.1179 5 0 0 Pass 3.1474 5 0 0 Pass 3.1768 5 0 0 Pass 3.2063 5 0 0 Pass 3.2358 5 0 0 Pass 3.2653 5 0 0 Pass 3.2948 4 0 0 Pass 3.3243 4 0 0 Pass 3.3538 3 0 0 Pass 3.3833 3 0 0 Pass 3.4128 3 0 0 Pass 3.4423 3 0 0 Pass 3.4718 3 0 0 Pass 3.5013 3 0 0 Pass 3.5308 3 0 0 Pass 3.5602 3 0 0 Pass 3.5897 3 0 0 Pass 3.6192 3 0 0 Pass 3.6487 3 0 0 Pass 3.6782 3 0 0 Pass Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 13 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 14 LID Report Portage Creek Ex pond Recalc 4/1/2016 11:48:13 AM Page 15 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. Portage Creek Ex pond Recalc 4/1/2016 11:48:43 AM Page 16 Appendix Predeveloped Schematic Portage Creek Ex pond Recalc 4/1/2016 11:48:43 AM Page 17 Mitigated Schematic Portage Creek Ex pond Recalc 4/1/2016 11:48:43 AM Page 18 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 Portage Creek Ex pond Recalc.wdm MESSU 25 PrePortage Creek Ex pond Recalc.MES 27 PrePortage Creek Ex pond Recalc.L61 28 PrePortage Creek Ex pond Recalc.L62 30 POCPortage Creek Ex pond Recalc1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 10 IMPLND 1 IMPLND 8 IMPLND 14 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Ex MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 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 *** 10 C, Forest, 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 *** 10 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 ********* Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 19 10 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 *** 10 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 10 0 4.5 0.08 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 10 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 10 0.2 0.5 0.35 6 0.5 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 10 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 *** 1 ROADS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 14 POND 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 8 0 0 1 0 0 0 14 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 14 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 *** 1 0 0 0 0 0 8 0 0 0 0 0 14 0 0 0 0 0 END IWAT-PARM1 Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 20 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 14 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 8 0 0 14 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 8 0 0 14 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Ex*** PERLND 10 12.11 COPY 501 12 PERLND 10 12.11 COPY 501 13 IMPLND 1 0.81 COPY 501 15 IMPLND 8 0.11 COPY 501 15 IMPLND 14 1.51 COPY 501 15 ******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 <-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 *** Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 21 # - # 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 # - # 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 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 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 22 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 Portage Creek Ex pond Recalc.wdm MESSU 25 MitPortage Creek Ex pond Recalc.MES 27 MitPortage Creek Ex pond Recalc.L61 28 MitPortage Creek Ex pond Recalc.L62 30 POCPortage Creek Ex pond Recalc1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 10 PERLND 16 IMPLND 1 IMPLND 4 IMPLND 5 IMPLND 8 IMPLND 14 RCHRES 1 COPY 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Additional Pond Storage MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 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 *** 10 C, Forest, Flat 1 1 1 1 27 0 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 *** Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 23 10 0 0 1 0 0 0 0 0 0 0 0 0 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 ********* 10 0 0 4 0 0 0 0 0 0 0 0 0 1 9 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 *** 10 0 0 0 0 0 0 0 0 0 0 0 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 10 0 4.5 0.08 400 0.05 0.5 0.996 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 10 0 0 2 2 0 0 0 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 *** 10 0.2 0.5 0.35 6 0.5 0.7 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 10 0 0 0 0 2.5 1 0 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 *** 1 ROADS/FLAT 1 1 1 27 0 4 ROOF TOPS/FLAT 1 1 1 27 0 5 DRIVEWAYS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 14 POND 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 4 0 0 1 0 0 0 5 0 0 1 0 0 0 8 0 0 1 0 0 0 14 0 0 1 0 0 0 END ACTIVITY Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 24 PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 0 1 9 4 0 0 4 0 0 0 1 9 5 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 14 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 *** 1 0 0 0 0 0 4 0 0 0 0 0 5 0 0 0 0 0 8 0 0 0 0 0 14 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 4 400 0.01 0.1 0.1 5 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 14 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 4 0 0 5 0 0 8 0 0 14 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 4 0 0 5 0 0 8 0 0 14 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Dv*** PERLND 10 10.22 RCHRES 1 2 PERLND 10 10.22 RCHRES 1 3 PERLND 16 0.94 RCHRES 1 2 PERLND 16 0.94 RCHRES 1 3 IMPLND 1 1.03 RCHRES 1 5 IMPLND 4 0.56 RCHRES 1 5 IMPLND 5 0.17 RCHRES 1 5 IMPLND 8 0.11 RCHRES 1 5 IMPLND 14 1.51 RCHRES 1 5 ******Routing****** PERLND 10 10.22 COPY 1 12 PERLND 16 0.94 COPY 1 12 Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 25 IMPLND 1 1.03 COPY 1 15 IMPLND 4 0.56 COPY 1 15 IMPLND 5 0.17 COPY 1 15 IMPLND 8 0.11 COPY 1 15 IMPLND 14 1.51 COPY 1 15 PERLND 10 10.22 COPY 1 13 PERLND 16 0.94 COPY 1 13 RCHRES 1 1 COPY 501 16 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 <-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 Additional Pond -005 1 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 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 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 0 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 0.05 0.0 138.0 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 0.0 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 90 4 Depth Area Volume Outflow1 Velocity Travel Time*** Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 26 (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)*** 0.000000 1.723326 0.000000 0.000000 0.019000 1.719586 0.032672 0.000000 0.038000 1.715849 0.065273 0.000000 0.057000 1.712114 0.097803 0.000000 0.076000 1.708383 0.130263 0.000000 0.095000 1.704654 0.162651 0.000000 0.114000 1.700927 0.194969 0.000000 0.133000 1.697204 0.227216 0.000000 0.152000 1.693483 0.259392 0.000000 0.171000 1.689764 0.291497 0.000000 0.190000 1.686049 0.323532 0.000000 0.209000 1.682336 0.355497 0.000000 0.228000 1.678627 0.387391 0.000000 0.247000 1.674919 0.419214 0.000000 0.266000 1.671215 0.450967 0.000000 0.285000 1.667514 0.482650 0.000000 0.304000 1.663815 0.514262 0.000000 0.323000 1.660119 0.545805 0.000000 0.342000 1.656426 0.577277 0.000000 0.361000 1.652736 0.608679 0.000000 0.380000 1.649049 0.640011 0.000000 0.399000 1.645365 0.671273 0.000000 0.418000 1.641683 0.702465 0.000000 0.437000 1.638004 0.733587 0.000000 0.456000 1.634329 0.764639 0.000000 0.475000 1.630656 0.795621 0.000000 0.494000 1.626986 0.826534 0.000000 0.513000 1.623319 0.857377 0.000000 0.532000 1.619655 0.888151 0.000000 0.551000 1.615994 0.918854 0.000000 0.570000 1.612336 0.949489 0.000000 0.589000 1.608681 0.980054 0.000000 0.608000 1.605029 1.010549 0.000000 0.627000 1.601380 1.040976 0.000000 0.646000 1.597734 1.071333 0.000000 0.665000 1.594092 1.101620 0.000000 0.684000 1.590452 1.131839 0.000000 0.703000 1.586815 1.161988 0.000000 0.722000 1.583181 1.192069 0.000000 0.741000 1.579551 1.222080 0.000000 0.760000 1.575923 1.252023 0.000000 0.779000 1.572299 1.281896 0.000000 0.798000 1.568677 1.311701 0.000000 0.817000 1.565059 1.341437 0.000000 0.836000 1.561444 1.371105 0.000000 0.855000 1.557833 1.400704 0.000000 0.874000 1.554224 1.430234 0.000000 0.893000 1.550618 1.459696 0.000000 0.912000 1.547016 1.489089 0.000000 0.931000 1.543417 1.518414 0.000000 0.950000 1.539821 1.547671 0.000000 0.969000 1.536229 1.576859 0.000000 0.988000 1.532640 1.605979 0.000000 1.007000 1.529053 1.635031 0.000000 1.026000 1.525471 1.664015 0.000000 1.045000 1.521891 1.692931 0.000000 1.064000 1.518315 1.721779 0.000000 1.083000 1.514742 1.750559 0.000000 1.102000 1.511173 1.779271 0.000000 1.121000 1.507607 1.807916 0.000000 1.140000 1.504044 1.836493 0.000000 1.159000 1.500484 1.865002 0.000000 1.178000 1.496928 1.893444 0.000000 1.197000 1.493376 1.921818 0.000000 1.216000 1.489826 1.950124 0.003714 1.235000 1.486281 1.978364 0.031591 1.254000 1.482738 2.006536 0.073762 1.273000 1.479199 2.034641 0.126376 1.292000 1.475664 2.062678 0.187662 Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 27 1.311000 1.472132 2.090649 0.256530 1.330000 1.468604 2.118552 0.332221 1.349000 1.465079 2.146389 0.414169 1.368000 1.461557 2.174158 0.501928 1.387000 1.458039 2.201861 0.595135 1.406000 1.454525 2.229497 0.693489 1.425000 1.451014 2.257066 0.796734 1.444000 1.447507 2.284569 0.904647 1.463000 1.444004 2.312005 1.017036 1.482000 1.440504 2.339374 1.133728 1.501000 1.437008 2.366678 1.254570 1.520000 1.433515 2.393914 1.379425 1.539000 1.430026 2.421085 1.508167 1.558000 1.426541 2.448189 1.640682 1.577000 1.423060 2.475227 1.776866 1.596000 1.419582 2.502199 1.916622 1.615000 1.416108 2.529105 2.059861 1.634000 1.412638 2.555946 2.206502 1.653000 1.409172 2.582720 2.356465 1.672000 1.405709 2.609428 2.509681 1.691000 1.402251 2.636071 2.666079 END FTABLE 1 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*** RCHRES 1 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1001 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 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 Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 28 MASS-LINK 16 RCHRES ROFLOW COPY INPUT MEAN END MASS-LINK 16 END MASS-LINK END RUN Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 29 Predeveloped HSPF Message File Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 30 Mitigated HSPF Message File Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 31 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. 2005-2016; 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 Portage Creek Ex pond Recalc 4/1/2016 11:48:44 AM Page 32 E. SPILL PREVENTION, CONTROL AND COUNTERMEASURES PLAN Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 32 - F. GEOTECHNICAL REPORT Insight Engineering Co. â€“Stormwater Site Plan Date Revised: 4/1/16 - 33 - February 2016 To Marc Hayes Page 5 CC Launa Peterson, Permit Technician Resubmittal Review of Stormwater Site Plan Report and Drainage Subject Sheets Technical Memorandum From Carla Talich, P.E. and Gina Franco, P.E., AECOM Date May 11, 2016 A resubmittal review has been performed on Portage Creek â€“ Phase I, per the request of Marc Hayes from the City of Arlington. Scope of work included review of both the Stormwater Site Plan Report and applicable drainage sheets of the civil drawings (C1.1, C2.1, C3.0, and C3.1) for compliance with the City of Arlington (COA) stormwater standards and the 2005 Washington State Department of Ecology Stormwater Management Manual (SWMMWW) for Western Washington. The Stormwater Site Plan Report and drainage sheets do not provide adequate information and are not compliant with the required codes as listed previously. As a result, the comments attached require additional information be provided in the drainage sheets, Stormwater Site Plan Report, and/or calculations. Please provide the requested information to allow completion of the Stormwater Site Plan Report and drainage sheets review process. Please provide a written response to the items attached with an indication as to the method of resolution and the location within the plans or storm drainage report. Due to the nature of the comments, further review may be necessary. Should you have any questions concerning the attached comments, please contact Gina Franco at (206) 438-2068 or gina.franco@aecom.com. Carla Talich, PE Gina Franco, PE Senior Civil Engineer Water Resource Engineer D +1-206-438-2125 D+1-206-438-2068 carla.talich@aecom.com gina.franco@aecom.com Portage Creek Development â€“ Phase I Review P age | 1 February 2016 Attachment 1 Stormwater Site Plan Report and Drainage Sheets Review Comments Portage Creek Development â€“ Phase I Review P age | 2 REVIEW COMMENT SUMMARY AND RESOLUTION SHEET Submittal: 2 Portage Creek - Phase I CODE A. Incorporated B. Open/Under Review Agency/Company/Reviewer C. Evaluated/Not Incorporated D. Beyond Scope/Not Evaluated Gina Franco E. Clarify or discuss Resubmittal Date: 4/11/2016 X. Comment closed Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Review (Resubmittal) Page No. Chapter/Section Code (initials) There isn't a interceptor trench or rock check dams shown on the 1 G. Franco C2.1 drawings. These items are mentioned in the construction phasing Reference to the interceptor trench and rock Reference to interceptor trench and rock check dams is still in note 4. check dams have been removed. the construction phasing note 4. No catch basin inserts are shown. Show where catch basin inserts 2 G. Franco C2.1 will be used. gmf For clarity, suggest that existing grading should no longer be shown, 3 G. Franco C2.1 only proposed grading. gmf Pipes discharging at the upstream end of the level spreader The outlet will now discharge to the appear to need armoring. Comply with outlet protection BMP 4 G. Franco C2.1 downstream ditch. Outlet protection is C209 in Volume II in the SWMMWW (2005) or clearly Element #8 doesn't specify how the outfalls will be protected. proposed. demonstrate how erosion control will be provided. Identify containment options and spill prevention measures for Refer to Appendix E for the Spill Prevention 5 G. Franco C2.1 Element #9. Plan located within the Stormwater Site Plan. Spill prevention plan was not attached COA Public Works Standards and 6 G. Franco C3.0 No pipe material, joints, or protective treatment specified for any pipe Specifications, Section 3-3.01 shown. Pipe material has been added. Pipe material is missing for the 12-inch SD pipe COA Public Works Standards and 7 G. Franco C3.0 Specify type of catch basin per the standard specifications. Provide Catch basin type is not called out on the plan view, specify type Specifications, Section 3-4.01 catch basin detail or section view in a profile. Type 1 catch basin has been called out. of catch basin per the standard specifications. COA Public Works Standards and 8 G. Franco C3.0 Specify type of catch basin and yard drain or roof drain per the Catch basin type is not called out on the plan view, specify type Specifications, Section 3-4.02 standard specifications. Type 1 catch basin has been called out. of catch basin per the standard specifications. COA Public Works Standards and 9 G. Franco C3.0 Section 3-4.06 states debris barrier is required, comply with the Specifications, Section 3-4.06 standard specifications. gmf COA Public Works Standards and 10 G. Franco C3.0 Specifications, There is no culvert protection provided for the stormwater outfall on There is no outlet protection shown on the revised drawings. Section 3-6.03 and 3- the drawings or described in the storm drainage report. Comply with Comply with Section 3-6.03 of the COA Standard Specs and 7 Section 3-6.03. Outlet protection has been provided. SWMMWW for outlet protection. COA Public Works Standards and 11 G. Franco C3.0 Specifications, The weir and pond outlet that is described in the drainage report are Details are not complete or clear. Comply with Section 3-6.03 Section 3-8.02 and 3- not shown on the drawings. Details should be provide to verify that The details have been revised, an angle iron and 3-8.08 of the COA Standard Specs. Calculations for weir 8.08 the weir and pond outlet comply with Section 3-6.03 and 3-8.08. deatil and trash barrier has been added. sizing and weir flow were not provided, but are needed. The pond bottom is greater than 30 feet, an access road should COA Public Works be provided. The pond shall comply with Section 3-8.03 of the Standards and COA Standard Specs and Volume III of SWMMWW. There is 12 G. Franco C3.0 Specifications, not enough information provided for the pond. Provide pond Section 3-8.03 The pond area is not clearly delineated on the drawings. The pond The proposed control plate is walking design documents and demonstrate that the pond meets current shall comply with Section 3-8.03. accessible and to be maintained by hand. standards. There is no backup for perforated stub out connection where infiltration is proposed. Comply with 3-9 for infiltration. Comply COA Public Works with 3-10.01 for the level spreader. Detail 1/C3.0 doesn't show Standards and pipe protection, concrete will crack in the driveways where 13 G. Franco C3.0 Specifications, perforated stub out is shown. Roof downspouts are 6 inch and Section 3-9.01 to 3- perforated stub out is 4 inches. Pipes should not decrease in 9.05 Perforated stub out connections are no longer size. Pipe sizing calculations are required. Downspout Provide infiltration or provide an explanation and backup to why it is proposed. The roof drains will outlet to a 2' Dispersion Trench should comply with Volume III, Section 3.1.2 not being used. gravel pad to discharge to the exisitng ditch. of SWMMWW. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Review (Resubmittal) Page No. Chapter/Section Code (initials) According to Section 3-12 5) "Easements for downspout roof COA Public Works drains, yard drains, and footing drawings are not required Standards and 14 G. Franco C3.0 unless these systems are shared by more than one property Specifications, Provide easements for downspout roof drain collection pipes per Easements are not required as this is a owner." Comply with Section 3-12. If each unit shares the Section 3-12 Section 3-12. condominium. gmf property tax then an easement is not required. COA Public Works Standards and The filter strip is no longer proposed. A water Details 5/C3.0 and 4/C3.1 don't match the plan view on C3.0. 14A G. Franco C3.0 quality filter will be provided for runnoff There is a disconnect between the details and plan that requires Specifications, Section 3-12 treatment. clarification. Stormwater Site COA, Stormwater 15 G. Franco gmf Plan Drainage Report No conveyance calculations were provided. Section 3.1, Page 16 G. Franco gmf 14 No bioswale is shown on the drawings. There is no design or details for the detention/retention pond, The project is only subjected to live volume There is not enough information provided for the pond. Provide 17 G. Franco Section 3.2, Page COA, Stormwater dispersion trench, or outlet from the pond. There is no backup for the requirements; additional dead storage is not pond design documents and demonstration on how pond meets 14 Drainage Report downstream analysis. current requirements. needed. COA, Stormwater There is no mention of the mitigation measures for Critical Areas A 18 G. Franco gmf Drainage Report and B. Minimum requirement (MR) #5 requires that on-site stormwater The level spreader and perforated stub out is not described in COA, Stormwater management BMPs to infiltrate, disperse, and retain stormwater Section 1.1, Page MR#5 19 G. Franco Drainage Report, 7 runoff onsite to the maximum extent feasible. Please address these The level spreader and perforated stub out connections Section 2.5.5 requirements. are no longer proposed. MR #6 requires that runoff treatment. See Volume V of the Section 5.3 text states that the filter strip will be at 2.5%, but the SWMMWW (2005), BMP T9.10 states that bioswales are not suitable drawing details 5/C3.0 doesn't have this slope. The text states for water quality. There is design criteria to use if a bioswale is the that the filter strip length will be 30 feet but the drawings (C3.0) only option. Please address this requirement. has only 20 feet. Demonstrate meeting the 10year flow rate for COA, Stormwater the level spreader. Level spreader doesn't comply with Section 1.1, Page 20 G. Franco Drainage Report, SWMMWW Section 3.5 Volume V. Jute or Coir is not 7 Section 2.5.6 acceptable. Level spreader is for basic treatment. The existing pond discharges into Krueger and Portage Creeks, both fish The filter strip is no longer proposed. A water bearing creeks. Water quality treatment shall be enhanced quality filter will be provided for runnoff treatment not basic. Provide documentation that this site meets treatment. requirements for enhanced treatment. Section 5, Page COA, Stormwater No infiltration is discussed whether applicable or not. No storm 21 G. Franco gmf 16 Drainage Report conveyance is discussed or designed. Section 5, Page COA, Stormwater 22 G. Franco gmf 18 Drainage Report Existing Basin Map was not provided. COA, Stormwater SWPPP, Page 23 G. Franco Drainage Report, How will the stormwater discharge be controlled? It should be gmf 32 Section 2.5.2 specified in Element #3 of the SWPPP. COA, Stormwater Element #4 should reference catch basin inserts, mulch or hydro SWPPP, Page 24 G. Franco Drainage Report, seeding, and sediment pond that is intended to be used on site as gmf 32 Section 2.5.2 shown on drawing C2.1. COA, Stormwater Add to Element #5 in the SWPPP or to the construction drawing SWPPP, Page 25 G. Franco Drainage Report, C2.1: Soil shall be stabilized at the end of the shift before a holiday or gmf 32 Section 2.5.2 weekend if needed based on the weather forecast. COA, Stormwater SWPPP, Page 26 G. Franco Drainage Report, No specific BMPs are listed to protect slopes in Element #6. Provide gmf 32 Section 2.5.2 BMPs as required by the City. COA, Stormwater SWPPP, Page 27 G. Franco Drainage Report, No specific BMPs are listed to protect inlets and culverts in Element gmf 32 and 33 Section 2.5.2 #7. Provide BMPs and inspection requirements required by the City. COA, Stormwater SWPPP, Page 28 G. Franco Drainage Report, No specific BMPs are listed to stabilize channels and outlets in gmf 33 Section 2.5.2 Element #8. Please provide BMPs as required by the City. COA, Stormwater SWPPP, Page 29 G. Franco Drainage Report, No specific BMPs are listed to control pollutants in Element #9. gmf 33 Section 2.5.2 Provide BMPs as required by the City. The WWHM model was not checked at this time due to insufficient Section 5, Page COA, Stormwater information provided. Provide the basin map or plans for the site and 30 G. Franco 20, Hydrologic Additional outlet information has been provided. Drainage Report offsite areas which show the location of basins and sub-basins which Model correspond to the analysis for the site. Can't complete review without pond design documentation. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Review (Resubmittal) Page No. Chapter/Section Code (initials) Section 5, Page Demonstrate adequate detention and water quality storage for this COA, Stormwater 31 G. Franco 20, Hydrologic project and provide documentation and model output for existing A water quality filter will be provided for runnoff Documentation was not provided, provide pond design Drainage Report Model pond to show it is suitable and allowable for use by this project. treatment. documentation. 32 G. Franco Appendix B, SWMMWW Volume Operation and maintenance (O&M) manual is incomplete. Provide The entire O&M Manual from the 2005 SWMMWW O&M Manual is incomplete. Comply with SWMMWW (2005) Page 34 I, Section 3.1.7 has been provided witihin Appendix B. O&M Manual as required by the SWMMWW (2005). Section 3.1.7. 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA. 98223 (360) 403 - 3551 Project Name: Portage Creek â€“ Phase I Permit No. : 535 Review Date : 5/20/2016 Contact: Insight Engineering Phone No. : (425) 303 - 9363 Review Phase : 1 Report Date : Reviewing Department : CED Applicant : Portage Creek LLC DWG Issue Date : # Rev. Dwg. or Additional Comment Response / Resolution City Spec. Ref. Reference Approved 1. MH Sheet C 1-1 Provide Basin Area of south side of 207th St. that contributes an The total existing basin contributing to the existing pond is offsite run on for total pond capacity. 14.54 Acres. A note has been added to sheet C1.1. M.H. 2. MH Sheet C 2.0 It appears that the grading will remove more than the recommended Please see the revised grading plan. We are not removing amount contained within the Geotechnical Report. more than 2â€™ of soil. M.H. 3. MH Sheet C 2.1 Identify where catch basin inserts are to be placed on the plan sheet. All proposed catch basin inserts have been added to sheet M.H. C2.1. 4. MH Sheet C 2.1 The installation of pea gravel is critical in this installation of silt fence Refer to detail 3 on sheet C2.1 for silt fence detail that since there is no storage area for runoff. references the installation of pea gravel at the base of the M.H. silt fence. 5. MH Sheet C 3.0 How is water quality and flow control being addressed by this Water quality and flow control are being met by directing proposed system? Callout buffer and wetland edge. the proposed runoff to the vegetation filter strip and flow control is handled with a weir at the outlet of the pond. Buffer and wetland edge is shown. 6. MH Sheet C 3.0 Why is the runoff not being directed to a level spreader before A level spreader has been proposed. Refer to sheet C3.0. M.H. entering pond as originally discussed? (Detail 5) 7. MH Sheet C 3.0 Where is the proposed weir design? Refer to sheet C3.0 for the proposed weir design. (Detail 7) M.H. 8. MH Sheet C 3.0 Delineate the Critical Area Buffer on this sheet. The critical area buffer is shown on sheet C3.0. M.H. 9. MH General Upon review of the Geotechnical Report produced by Associated Please see the site plan exhibit with the cross sections. Earth Sciences, Inc. whereas it states, that per their recommendation, Phases II and III along with the geotechnical cross sections no homes should be built any further east than Geologic Cross â€“ have been added to sheet C1.2. Section C-Câ€™ because of the high risk of future impacts caused by landslide activity. Please provide a sheet that also includes the proposed Phase II and Phase III along with Geologic Cross Sections A- Aâ€™, B-Bâ€™ and C-Câ€™ delineated upon it. Stationing should be shown for clarity on this sheet. 10. GS Sheet 4.0 Show water meters in proper location between curb and sidewalk per The proposed location of water meters have been revised to M.H. COA Standard W-070. be located within the planter per detail. 11. GS Sheet 4.0 Show water main in proper alignment with valving. The water main and valving has been aligned. M.H. 12. GS Sheet 4.0 Show water valves in proper configuration (West-East and South). Please refer to the revised plan. Proper water valve Contact Gary Schlagel at 360-403-3529 configuration has been shown. 13. FR Sheet C 3.1 Elimination of two 6" sewer lines and replace with one 8" line is a cost An 8â€ line is now proposed to serve the development. savings and meets current standards for construction. Standards M.H. paragraphs are cited in the redlines. See Attachment 1-A. 18204 59th Avenue NE REVIEW COMMENT FORM Arlington, WA. 98223 (360) 403 - 3551 Project Name: Portage Creek â€“ Phase I Permit No.:535 Review Date: 5/20/2016 Contact: Insight Engineering Phone No.:425 303-9363 Review Phase: 1 Report Date: Reviewing Dept.: CED Applicant: Portage Creek LLC DWG Issue Date: # Rev. Dwg. or Additional Comment Response / Resolution City Spec. Ref. Reference Approved 14 GS Sheet 4.0 Plan only shows 4 meters, since 6 units are proposed shows 6 meters. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's R Know what's REVIEW COMMENT SUMMARY AND RESOLUTION SHEET Submittal: Portage Creek Estates CODE A. Incorporated B. Open/Under Review Agency/Company/Reviewer C. Evaluated/Not Incorporated D. Beyond Scope/Not Evaluated Robert O'Brien E. Clarify or discuss Submittal Date: 7/26/2016 X. Comment closed Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) 1 O'Brien Hydraulic Report I need the information for the orifice structure to be in the WWHM A screenshot for the proposed notches from WWHM printed portion of the report in your appendix to verify. On that note has been included at the end of the WWHM Report the galvanized wire mesh being used will it extend to elevation within the Stormwater Site Plan. The notch 143.85? This would be good to note in the report as a means of dimensions are provided within the figures. Detail 6 A RO on sheet C3.0 has been revised to show a cross- preventing clogging of the small orifices being used. Also I think this section of the proposed wire mesh, aluminized metal feature should be aluminized metal and not galvanized (zinc leaching). has been referenced. 2 O'Brien Hydraulic Report In your WWHM model you are creating a larger pond (impervious The net impervious created from the rise of water area), this net new impervious area should be reflected in the model. surface is only 87 SF (0.002 AC) and was therefore In the report you stated an existing pond impervious area of 1.51 Ac, considered negligible within the impervious area A RO whatever the net pond increase above this should be reflected in consideration. model. 3 O'Brien Drainage Plan The driveway leading to the bay filter is pretty steep with a shallow and An extruded curb will be provided at the end of the wide flow spread (I am assuming from looking at detail), the inlet roadway to direct the road runoff towards the provided by the bay filter may not provide enough interception of flow Bayfilter. to capture the runoff. A couple options may be to provide grading and A RO curb at end of street to intercept and route bypassed flows to bay filter, or to provide a upstream catch basin to intercept runoff and do inlet analysis calculation for Q bypass. 4 O'Brien Drainage Plan Update note number 2 on the drainage plan to state treatment The note has been revised. A RO performed by proposed bay filter facility and not existing swale. 5 O'Brien Hydraulic Report Update predeveloped basin exhibit to be 0.72 Ac and not 0.79 Ac (or The existing basin map has been updated to 0.72 Ac. A RO verify which is correct). 6 O'Brien Hydraulic Report Model just the Phase 1 improvements. The weir may have to be The model has been revised to only include the phased or changed as improvements progress. The current design Phase 1 improvements. Refer to the revised expects an increase of runoff from 1.89 Ac of converted forest. If the drainage report for more information. A RO actual system sees less (during phase 1), then the net increase from Phase 1 activities would just run through the system without being detained. 7 Update to 2012 DOE manual requirements. The drainage report has been updated to O'Brien Hydraulic Report A RO reference the 2012 DOE manual requirements. 8 Update figure 2.2 to show greater than 5,000 sf of new impervious. The figure has been revised to show greater than O'Brien Hydraulic Report A RO 5,000 SF of new impervious. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) 9 The WWHM ahs a sketched in pond element, but your SSD table seems off, I would expect the Area to be increasing as elevation The WWHM has been revised to use a SSD that O'Brien Hydraulic Report rises? I would recommend using CAD and just inputting your areas in better represents the stage and storage values of the A RO to the SSD table starting from top of pond surface up to your overflow existing pond. elevation. January 2016 GENERAL USE LEVEL DESIGNATON FOR BASIC TREATMENT CONDITIONAL USE LEVEL DESIGNATION FOR ENHANCED, AND PHOSPHORUS TREATMENT For BaySaver Technologies, LLC BayFilterâ„¢ Ecologyâ€™s Decision: 1. Based on BaySaver Technologiesâ€™ application submissions, Ecology hereby issues a Basic Treatment General Use Level Designation (GULD) for the BayFilterâ„¢. ï‚· As a stormwater treatment device for Basic treatment (TSS) removal. ï‚· The Basic Treatment GULD is for both the BayFilter Cartridge (BFC) and Enhanced Media Cartridge (EMC) and limited to the following maximum flow rates: a. BFC Cartridge maximum flow rate of 0.70 gpm/sq ft o 30 gpm (0.067 cfs) per cartridge (example dimensions: 26-inches in diameter, 29-inches tall (43 sq ft filter area)) ï‚§ Canisters that provide 0.70 gpm per sq ft filter area, regardless of dimensions meet this requirement o Media Blend of Silica Sand, Perlite, and Activated Alumina b. EMC Cartridge maximum flow rate of 0.50 gpm/sq ft o 45 gpm (0.10 cfs) per cartridge (example dimensions 30-inch diameter, 30- inches tall (90 sq ft filter area)) ï‚§ Canisters that provide 0.50 gpm per sq ft filter area, regardless of dimensions meet this requirement o 75 gpm (0.167 cfs) per cartridge (example dimensions 39-inch diameter, 30- inches tall) (150 sq ft filter area)) ï‚§ Canisters that provide 0.50 gpm per sq ft filter area, regardless of dimensions meet this requirement o Media Blend of Zeolite, Perlite, and Activated Alumina 2. Based on BaySaver Technologiesâ€™ application submissions, Ecology hereby issues a Enhanced and Phosphorus Conditional Use Level Designation (CULD) for the BayFilterâ„¢ cartridges. ï‚· As a stormwater treatment device for Enhanced treatment (dissolved Cu and dissolved Zn removal) and Phosphorus treatment. ï‚· Sized at a design rates no greater than those listed above (GULD (Basic) Flow rates). 3. Ecology approves use of BayFilterâ„¢ Cartridges for treatment at the above flow rates per cartridge. Designers shall calculate the water quality design flow rates using the following procedures: ï‚· Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model. ï‚· Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual. ï‚· Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 4. The CULDs expire on December 31, 2016 unless extended by Ecology, and are subject to the conditions specified below. 5. The GULD has no expiration date, but it may be amended or revoked by Ecology, and is subject to the conditions specified below. Ecologyâ€™s Conditions of Use: BayFilterâ„¢ units shall comply with these conditions: 1. Design, assemble, install, operate, and maintain BayFilterâ„¢ units in accordance with BaySaver Technologiesâ€™ applicable manuals and documents and the Ecology Decision. 2. Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent upon the efficiency of the device and the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a â€œone size fits allâ€ maintenance cycle for a particular model/size of manufactured filter treatment device. ï‚· BaySaver recommends that the following be considered during the design application of the BayFilter Cartridge systems: o Water Quality Flow Rate o Anticipated Pollutant Load o Maintenance Frequency ï‚· A BayFilter System tested adjacent to construction activity required maintenance after 4-months of operation. Monitoring personnel observed construction washout in the device during the testing period; the construction activity may have resulted in a shorter maintenance interval. ï‚· Ecology has found that pre-treatment device prior to the BayFilter system can provide a reduction in pollutant loads on these systems, thereby extending the maintenance interval. ï‚· Test results provided to Ecology from other BayFilter Systems, including the above mentioned system that was evaluated again after construction activities had been completed, have indicated the BayFilter System typically has longer maintenance intervals, sometimes exceeding 12-months. ï‚· The BayFilter system contains filter fabric that is highly oleophilic (oil absorptive). When sufficient quantities of oils are present in the runoff, the oil and subsequent sediment particles may become attached to the fabric. As a result, it may compromise the maintenance interval of the BayFilter system. Oil control BMPâ€™s should be installed upstream of BayFilter installations if warranted, and/or the BayFilter system should be inspected after any known oil spill or release. ï‚· Owners/operators must inspect BayFilter systems for a minimum of twelve months from the start of post-construction operation to determine site-specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to SWMMEW, the wet season in eastern Washington is October 1 to June 30.) After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections or the manufacturerâ€™s anticipated maintenance interval, whichever is more frequent. ï‚· Conduct inspections by qualified personnel, follow manufacturerâ€™s guidelines, and must use methods capable of determining either a decrease in treated effluent flowrate and/or a decrease in pollutant removal ability. 3. When inspections are performed, the following findings typically serve as maintenance triggers: ï‚· Accumulated vault sediment depths exceed an average of 2 inches, or ï‚· Accumulated sediment depths on the tops of the cartridges exceed an average of 0.5 inches, or ï‚· Standing water remains in the vault between rain events. ï‚· Bypass during storms smaller than the design storm. ï‚· Note: If excessive floatables (trash and debris) are present, perform minor maintenance consisting of gross solids removal, not cartridge replacement. 4. BaySaver Technologies Inc. commits to submitting a QAPP for Ecology approval by February 1, 2015 that meets the TAPE requirements for attaining a GULD for enhanced and phosphorus treatment. The monitoring site(s) chosen should be reflective of the productâ€™s treatment intent. BaySaver shall monitor sites prior to installation of the canister to ensure concentrations of the monitored constituents are within TAPE guidelines. 5. BaySaver Technologies Inc. shall complete all required testing and submit a TER for enhanced and phosphorus treatment for Ecology review by April 30, 2015. 6. BaySaver Technologies Inc. may request Ecology to grant deadline or expiration date extensions, upon showing cause for such extensions. 7. Discharges from the BayFilterâ„¢ units shall not cause or contribute to water quality standards violations in receiving waters. Applicant: Advanced Drainage Systems - BaySaver Applicantâ€™s Address: 4640 Trueman Blvd Hilliard, Ohio 43065 Application Documents: ï‚· Technical Evaluation Report BayFilter System, Grandview Place Apartments, Vancouver, Washington and Appendices A through O (May 18, 2011) ï‚· Washington State Department of Ecology Technology Assessment Protocol â€“ Environmental BayFilterâ„¢ Conditional Use Designation Application (March 2007) ï‚· BaySaver Technologies, Inc. BayFilterâ„¢ System Washington State Technical and Design Manual, Version 1.1 (December 2006) ï‚· Efficiency Assessment of BaySeparator and Bay filter Systems in the Richard Montgomery High School January 6.2009. ï‚· Evaluation of MASWRC Sample Collection, Sample Analysis, and Data Analysis, December 27, 2008 ï‚· Letter from Mid-Atlantic Stormwater Research Center to BaySaver Technologies, In. dated October 22, 2009. ï‚· Letter from Mid-Atlantic Stormwater Research Center to BaySaver Technologies, In. dated November 5, 2009. ï‚· Maryland Department of the Environment letter to BaySaver Technologies dated Jan. 13, 2008 regarding approval of BayFilter as a standalone BMP for Stormwater treatment. ï‚· NJCAT letter to BaySaver Technologies dated June 18, 2009 regarding Interim Certification. Applicantâ€™s Use Level Request: ï‚Ÿ General use level designation as a basic, enhanced, and phosphorus treatment device in accordance with Ecologyâ€™s Stormwater Management Manual for Western Washington. Applicantâ€™s Performance Claims: ï‚Ÿ Removes and retains 80% of TSS based on laboratory testing using Sil-Co-Sil 106 as a laboratory stimulant. ï‚Ÿ Removes 42% of dissolved Copper and 38% of dissolved Zinc. ï‚Ÿ Expected to remove 50% of the influent phosphorus load. Ecologyâ€™s Recommendations: Ecology finds that: ï‚· Ecology should provide BaySaver Technologies, Inc. with the opportunity to demonstrate, through additional laboratory and field-testing, whether the BayFilterâ„¢ system (as a single treatment facility) can attain Ecologyâ€™s Enhanced Treatment and Phosphorus removal goals. Findings of Fact: ï‚Ÿ Based on field testing in Vancouver, WA, at a flow rate less than or equal to 30 gpm per canister, the BayFilterâ„¢ system demonstrated a total suspended solids removal efficiency of greater than 80% for influent concentrations between 100 and 200 mg/l and an effluent concentration < 20 mg/l for influent concentration < 100 mg/l. ï‚Ÿ Based on laboratory testing, at a flowrate of 30 GPM per filter, the BayFilterâ„¢ system demonstrated a total suspended solids removal efficiency of 81.5% using Sil-Co-Sil 106 with an average influent concentration of 268 mg/L and zero initial sediment loading. ï‚Ÿ Based on laboratory testing, at a flowrate of 30 GPM per filter, the BayFilterâ„¢ system demonstrated a dissolved phosphorus removal efficiency of 55% using data from the Richard Montgomery High School field-testing. The average influent concentration was 0.31 mg/L phosphorus and zero initial sediment loading. ï‚Ÿ Based on data from field-testing at Richard Montgomery High School in Rockville, MD the BayFilter system demonstrated a Cu removal efficiency of 51% and 41% for total and dissolved Cu respectively. Average influent concentrations are 41.6 Âµg/l total and 17.5 Âµg/l dissolved. ï‚Ÿ Based on data from field-testing at Richard Montgomery High School in Rockville, MD the BayFilter system demonstrated a Zn removal efficiency of 45% and 38% for total and dissolved Cu, respectively. Average influent concentrations are 354 Âµg/l total and 251 Âµg/l dissolved, respectively. Other BayFilterâ„¢ Related Issues to be Addressed By the Company: 1. The Washington State field test results submitted in the TER do not yet show whether the BayFilterâ„¢ system can reliably attain 30% removal of dissolved Cu, 60% removal of dissolved Zn, or 50% removal of Total Phosphorus found on local highways, parking lots, and other high-use areas at the design operating rate. 2. BaySaver Technologies, Inc. should test a variety of operating rates to establish conservative design flow rates. 3. The manufacturer should continue to monitor the system to measure bypass and to calculate if the system treats 91% of the volume of the total annual runoff volume. 4. The manufacturer should test the system under normal operating conditions, with a partially pollutant filled settling basin. Results obtained for â€œcleanâ€ systems may not be representative of typical performance. 5. Conduct field-testing at sites that are indicative of the treatment goals. 6. BaySaver should continue monitoring the system for a longer period to help establish a maintenance period and to obtain data from additional qualified storms. Conduct testing to obtain information about maintenance requirements in order to come up with a maintenance cycle. 7. Conduct loading tests on the filter to determine maximum treatment life of the system. 8. Conduct testing to determine if oils and grease affect the treatment ability of the filter. This should include a determination of how oil and grease may affect the ion-exchange capacity of the system if BaySaver wishes to make claims for phosphorus removal. 9. BaySaver should develop easy-to-implement methods of determining when a BayFilter system requires maintenance (cleaning and filter replacement). 10. BaySaver must update their O&M documents to include information and instructions on the â€œ24-hour draw-downâ€ method to determine if cartridges need replacing. Technology Description: Download at www.BaySaver.com Contact Information: Applicant: Daniel Figola Advanced Drainage Systems - BaySaver 4640 Trueman Blvd Hilliard, Ohio 43065 (614) 658-0265 dfigola@ads-pipe.com Applicant website: www.BaySaver.com Ecology web link: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/index.html Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Revision History Date Revision April 2008 Original use-level-designation document February 2010 Revision August 2011 GULD awarded for Basic Treatment April 2012 Maintenance requirements updated. August 2012 Revised design storm criteria December 2012 Revised contact information and document formatting December 2013 Revised expiration and submittal dates December 2014 Revised Inspection/maintenance discussion, Updated cartridge descriptions January 2015 Revised discussion for flow rate controls December 2015 Revised Expiration date January 2016 Revised Manufacturer Contact Information and expiration date July 28th, 2016 ATTN: Jacob Mealy â€“ Insight Engineering RE: BayFilter for Portage Bay Phase 1 Project Dear Jacob, This letter confirms that the BayFilter on the project referenced above will provide stormwater treatment per the WADOE Conditional Use Level approval for Enhanced Treatment. Please contact me if you have any questions. Thank you. Regards, Mike LeMaster Water Quality Product Manager Advanced Drainage Systems, Inc. mike.lemaster@ads-pipe.com Phone: 360-507-2354 A D V A N C E D D R A I N A G E S Y S T E M S , I N C . 4 6 4 0 T R U E M A N B O U L E V A R D , H I L L I A R D , O H 4 3 0 2 6 T E L: 6 1 4 / 6 5 8 - 0 0 5 0 8 0 0 / 7 3 3 - 7 4 7 3 H T T P : / / W W W . A D S - P I P E . C O M January 2016 GENERAL USE LEVEL DESIGNATON FOR BASIC TREATMENT CONDITIONAL USE LEVEL DESIGNATION FOR ENHANCED, AND PHOSPHORUS TREATMENT For BaySaver Technologies, LLC BayFilterâ„¢ Ecologyâ€™s Decision: 1. Based on BaySaver Technologiesâ€™ application submissions, Ecology hereby issues a Basic Treatment General Use Level Designation (GULD) for the BayFilterâ„¢. ï‚· As a stormwater treatment device for Basic treatment (TSS) removal. ï‚· The Basic Treatment GULD is for both the BayFilter Cartridge (BFC) and Enhanced Media Cartridge (EMC) and limited to the following maximum flow rates: a. BFC Cartridge maximum flow rate of 0.70 gpm/sq ft o 30 gpm (0.067 cfs) per cartridge (example dimensions: 26-inches in diameter, 29-inches tall (43 sq ft filter area)) ï‚§ Canisters that provide 0.70 gpm per sq ft filter area, regardless of dimensions meet this requirement o Media Blend of Silica Sand, Perlite, and Activated Alumina b. EMC Cartridge maximum flow rate of 0.50 gpm/sq ft o 45 gpm (0.10 cfs) per cartridge (example dimensions 30-inch diameter, 30- inches tall (90 sq ft filter area)) ï‚§ Canisters that provide 0.50 gpm per sq ft filter area, regardless of dimensions meet this requirement o 75 gpm (0.167 cfs) per cartridge (example dimensions 39-inch diameter, 30- inches tall) (150 sq ft filter area)) ï‚§ Canisters that provide 0.50 gpm per sq ft filter area, regardless of dimensions meet this requirement o Media Blend of Zeolite, Perlite, and Activated Alumina 2. Based on BaySaver Technologiesâ€™ application submissions, Ecology hereby issues a Enhanced and Phosphorus Conditional Use Level Designation (CULD) for the BayFilterâ„¢ cartridges. ï‚· As a stormwater treatment device for Enhanced treatment (dissolved Cu and dissolved Zn removal) and Phosphorus treatment. ï‚· Sized at a design rates no greater than those listed above (GULD (Basic) Flow rates). 3. Ecology approves use of BayFilterâ„¢ Cartridges for treatment at the above flow rates per cartridge. Designers shall calculate the water quality design flow rates using the following procedures: ï‚· Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model. ï‚· Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual. ï‚· Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 4. The CULDs expire on December 31, 2016 unless extended by Ecology, and are subject to the conditions specified below. 5. The GULD has no expiration date, but it may be amended or revoked by Ecology, and is subject to the conditions specified below. Ecologyâ€™s Conditions of Use: BayFilterâ„¢ units shall comply with these conditions: 1. Design, assemble, install, operate, and maintain BayFilterâ„¢ units in accordance with BaySaver Technologiesâ€™ applicable manuals and documents and the Ecology Decision. 2. Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent upon the efficiency of the device and the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a â€œone size fits allâ€ maintenance cycle for a particular model/size of manufactured filter treatment device. ï‚· BaySaver recommends that the following be considered during the design application of the BayFilter Cartridge systems: o Water Quality Flow Rate o Anticipated Pollutant Load o Maintenance Frequency ï‚· A BayFilter System tested adjacent to construction activity required maintenance after 4-months of operation. Monitoring personnel observed construction washout in the device during the testing period; the construction activity may have resulted in a shorter maintenance interval. ï‚· Ecology has found that pre-treatment device prior to the BayFilter system can provide a reduction in pollutant loads on these systems, thereby extending the maintenance interval. ï‚· Test results provided to Ecology from other BayFilter Systems, including the above mentioned system that was evaluated again after construction activities had been completed, have indicated the BayFilter System typically has longer maintenance intervals, sometimes exceeding 12-months. ï‚· The BayFilter system contains filter fabric that is highly oleophilic (oil absorptive). When sufficient quantities of oils are present in the runoff, the oil and subsequent sediment particles may become attached to the fabric. As a result, it may compromise the maintenance interval of the BayFilter system. Oil control BMPâ€™s should be installed upstream of BayFilter installations if warranted, and/or the BayFilter system should be inspected after any known oil spill or release. ï‚· Owners/operators must inspect BayFilter systems for a minimum of twelve months from the start of post-construction operation to determine site-specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to SWMMEW, the wet season in eastern Washington is October 1 to June 30.) After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections or the manufacturerâ€™s anticipated maintenance interval, whichever is more frequent. ï‚· Conduct inspections by qualified personnel, follow manufacturerâ€™s guidelines, and must use methods capable of determining either a decrease in treated effluent flowrate and/or a decrease in pollutant removal ability. 3. When inspections are performed, the following findings typically serve as maintenance triggers: ï‚· Accumulated vault sediment depths exceed an average of 2 inches, or ï‚· Accumulated sediment depths on the tops of the cartridges exceed an average of 0.5 inches, or ï‚· Standing water remains in the vault between rain events. ï‚· Bypass during storms smaller than the design storm. ï‚· Note: If excessive floatables (trash and debris) are present, perform minor maintenance consisting of gross solids removal, not cartridge replacement. 4. BaySaver Technologies Inc. commits to submitting a QAPP for Ecology approval by February 1, 2015 that meets the TAPE requirements for attaining a GULD for enhanced and phosphorus treatment. The monitoring site(s) chosen should be reflective of the productâ€™s treatment intent. BaySaver shall monitor sites prior to installation of the canister to ensure concentrations of the monitored constituents are within TAPE guidelines. 5. BaySaver Technologies Inc. shall complete all required testing and submit a TER for enhanced and phosphorus treatment for Ecology review by April 30, 2015. 6. BaySaver Technologies Inc. may request Ecology to grant deadline or expiration date extensions, upon showing cause for such extensions. 7. Discharges from the BayFilterâ„¢ units shall not cause or contribute to water quality standards violations in receiving waters. Applicant: Advanced Drainage Systems - BaySaver Applicantâ€™s Address: 4640 Trueman Blvd Hilliard, Ohio 43065 Application Documents: ï‚· Technical Evaluation Report BayFilter System, Grandview Place Apartments, Vancouver, Washington and Appendices A through O (May 18, 2011) ï‚· Washington State Department of Ecology Technology Assessment Protocol â€“ Environmental BayFilterâ„¢ Conditional Use Designation Application (March 2007) ï‚· BaySaver Technologies, Inc. BayFilterâ„¢ System Washington State Technical and Design Manual, Version 1.1 (December 2006) ï‚· Efficiency Assessment of BaySeparator and Bay filter Systems in the Richard Montgomery High School January 6.2009. ï‚· Evaluation of MASWRC Sample Collection, Sample Analysis, and Data Analysis, December 27, 2008 ï‚· Letter from Mid-Atlantic Stormwater Research Center to BaySaver Technologies, In. dated October 22, 2009. ï‚· Letter from Mid-Atlantic Stormwater Research Center to BaySaver Technologies, In. dated November 5, 2009. ï‚· Maryland Department of the Environment letter to BaySaver Technologies dated Jan. 13, 2008 regarding approval of BayFilter as a standalone BMP for Stormwater treatment. ï‚· NJCAT letter to BaySaver Technologies dated June 18, 2009 regarding Interim Certification. Applicantâ€™s Use Level Request: ï‚Ÿ General use level designation as a basic, enhanced, and phosphorus treatment device in accordance with Ecologyâ€™s Stormwater Management Manual for Western Washington. Applicantâ€™s Performance Claims: ï‚Ÿ Removes and retains 80% of TSS based on laboratory testing using Sil-Co-Sil 106 as a laboratory stimulant. ï‚Ÿ Removes 42% of dissolved Copper and 38% of dissolved Zinc. ï‚Ÿ Expected to remove 50% of the influent phosphorus load. Ecologyâ€™s Recommendations: Ecology finds that: ï‚· Ecology should provide BaySaver Technologies, Inc. with the opportunity to demonstrate, through additional laboratory and field-testing, whether the BayFilterâ„¢ system (as a single treatment facility) can attain Ecologyâ€™s Enhanced Treatment and Phosphorus removal goals. Findings of Fact: ï‚Ÿ Based on field testing in Vancouver, WA, at a flow rate less than or equal to 30 gpm per canister, the BayFilterâ„¢ system demonstrated a total suspended solids removal efficiency of greater than 80% for influent concentrations between 100 and 200 mg/l and an effluent concentration < 20 mg/l for influent concentration < 100 mg/l. ï‚Ÿ Based on laboratory testing, at a flowrate of 30 GPM per filter, the BayFilterâ„¢ system demonstrated a total suspended solids removal efficiency of 81.5% using Sil-Co-Sil 106 with an average influent concentration of 268 mg/L and zero initial sediment loading. ï‚Ÿ Based on laboratory testing, at a flowrate of 30 GPM per filter, the BayFilterâ„¢ system demonstrated a dissolved phosphorus removal efficiency of 55% using data from the Richard Montgomery High School field-testing. The average influent concentration was 0.31 mg/L phosphorus and zero initial sediment loading. ï‚Ÿ Based on data from field-testing at Richard Montgomery High School in Rockville, MD the BayFilter system demonstrated a Cu removal efficiency of 51% and 41% for total and dissolved Cu respectively. Average influent concentrations are 41.6 Âµg/l total and 17.5 Âµg/l dissolved. ï‚Ÿ Based on data from field-testing at Richard Montgomery High School in Rockville, MD the BayFilter system demonstrated a Zn removal efficiency of 45% and 38% for total and dissolved Cu, respectively. Average influent concentrations are 354 Âµg/l total and 251 Âµg/l dissolved, respectively. Other BayFilterâ„¢ Related Issues to be Addressed By the Company: 1. The Washington State field test results submitted in the TER do not yet show whether the BayFilterâ„¢ system can reliably attain 30% removal of dissolved Cu, 60% removal of dissolved Zn, or 50% removal of Total Phosphorus found on local highways, parking lots, and other high-use areas at the design operating rate. 2. BaySaver Technologies, Inc. should test a variety of operating rates to establish conservative design flow rates. 3. The manufacturer should continue to monitor the system to measure bypass and to calculate if the system treats 91% of the volume of the total annual runoff volume. 4. The manufacturer should test the system under normal operating conditions, with a partially pollutant filled settling basin. Results obtained for â€œcleanâ€ systems may not be representative of typical performance. 5. Conduct field-testing at sites that are indicative of the treatment goals. 6. BaySaver should continue monitoring the system for a longer period to help establish a maintenance period and to obtain data from additional qualified storms. Conduct testing to obtain information about maintenance requirements in order to come up with a maintenance cycle. 7. Conduct loading tests on the filter to determine maximum treatment life of the system. 8. Conduct testing to determine if oils and grease affect the treatment ability of the filter. This should include a determination of how oil and grease may affect the ion-exchange capacity of the system if BaySaver wishes to make claims for phosphorus removal. 9. BaySaver should develop easy-to-implement methods of determining when a BayFilter system requires maintenance (cleaning and filter replacement). 10. BaySaver must update their O&M documents to include information and instructions on the â€œ24-hour draw-downâ€ method to determine if cartridges need replacing. Technology Description: Download at www.BaySaver.com Contact Information: Applicant: Daniel Figola Advanced Drainage Systems - BaySaver 4640 Trueman Blvd Hilliard, Ohio 43065 (614) 658-0265 dfigola@ads-pipe.com Applicant website: www.BaySaver.com Ecology web link: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/index.html Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Revision History Date Revision April 2008 Original use-level-designation document February 2010 Revision August 2011 GULD awarded for Basic Treatment April 2012 Maintenance requirements updated. August 2012 Revised design storm criteria December 2012 Revised contact information and document formatting December 2013 Revised expiration and submittal dates December 2014 Revised Inspection/maintenance discussion, Updated cartridge descriptions January 2015 Revised discussion for flow rate controls December 2015 Revised Expiration date January 2016 Revised Manufacturer Contact Information and expiration date July 28th, 2016 ATTN: Jacob Mealy â€“ Insight Engineering RE: BayFilter for Portage Bay Phase 1 Project Dear Jacob, This letter confirms that the BayFilter on the project referenced above will provide stormwater treatment per the WADOE Conditional Use Level approval for Enhanced Treatment. Please contact me if you have any questions. Thank you. Regards, Mike LeMaster Water Quality Product Manager Advanced Drainage Systems, Inc. mike.lemaster@ads-pipe.com Phone: 360-507-2354 A D V A N C E D D R A I N A G E S Y S T E M S , I N C . 4 6 4 0 T R U E M A N B O U L E V A R D , H I L L I A R D , O H 4 3 0 2 6 T E L: 6 1 4 / 6 5 8 - 0 0 5 0 8 0 0 / 7 3 3 - 7 4 7 3 H T T P : / / W W W . A D S - P I P E . C O M REVIEW COMMENT SUMMARY AND RESOLUTION SHEET Submittal: Portage Creek Estates CODE A. Incorporated B. Open/Under Review Agency/Company/Reviewer C. Evaluated/Not Incorporated D. Beyond Scope/Not Evaluated Robert O'Brien E. Clarify or discuss Submittal Date: 7/26/2016 X. Comment closed Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) 1 O'Brien Hydraulic Report I need the information for the orifice structure to be in the WWHM A screenshot for the proposed notches from WWHM printed portion of the report in your appendix to verify. On that note has been included at the end of the WWHM Report the galvanized wire mesh being used will it extend to elevation within the Stormwater Site Plan. The notch 143.85? This would be good to note in the report as a means of dimensions are provided within the figures. Detail 6 A RO on sheet C3.0 has been revised to show a cross- preventing clogging of the small orifices being used. Also I think this section of the proposed wire mesh, aluminized metal feature should be aluminized metal and not galvanized (zinc leaching). has been referenced. 2 O'Brien Hydraulic Report In your WWHM model you are creating a larger pond (impervious The net impervious created from the rise of water area), this net new impervious area should be reflected in the model. surface is only 87 SF (0.002 AC) and was therefore In the report you stated an existing pond impervious area of 1.51 Ac, considered negligible within the impervious area A RO whatever the net pond increase above this should be reflected in consideration. model. 3 O'Brien Drainage Plan The driveway leading to the bay filter is pretty steep with a shallow and An extruded curb will be provided at the end of the wide flow spread (I am assuming from looking at detail), the inlet roadway to direct the road runoff towards the provided by the bay filter may not provide enough interception of flow Bayfilter. to capture the runoff. A couple options may be to provide grading and A RO curb at end of street to intercept and route bypassed flows to bay filter, or to provide a upstream catch basin to intercept runoff and do inlet analysis calculation for Q bypass. 4 O'Brien Drainage Plan Update note number 2 on the drainage plan to state treatment The note has been revised. A RO performed by proposed bay filter facility and not existing swale. 5 O'Brien Hydraulic Report Update predeveloped basin exhibit to be 0.72 Ac and not 0.79 Ac (or The existing basin map has been updated to 0.72 Ac. A RO verify which is correct). 6 O'Brien Hydraulic Report Model just the Phase 1 improvements. The weir may have to be The model has been revised to only include the phased or changed as improvements progress. The current design Phase 1 improvements. Refer to the revised expects an increase of runoff from 1.89 Ac of converted forest. If the drainage report for more information. A RO actual system sees less (during phase 1), then the net increase from Phase 1 activities would just run through the system without being detained. 7 Update to 2012 DOE manual requirements. The drainage report has been updated to O'Brien Hydraulic Report A RO reference the 2012 DOE manual requirements. 8 Update figure 2.2 to show greater than 5,000 sf of new impervious. The figure has been revised to show greater than O'Brien Hydraulic Report A RO 5,000 SF of new impervious. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) 9 The WWHM ahs a sketched in pond element, but your SSD table seems off, I would expect the Area to be increasing as elevation The WWHM has been revised to use a SSD that O'Brien Hydraulic Report rises? I would recommend using CAD and just inputting your areas in better represents the stage and storage values of the A RO to the SSD table starting from top of pond surface up to your overflow existing pond. elevation. REVIEW COMMENT SUMMARY AND RESOLUTION SHEET Submittal: Portage Creek Estates CODE A. Incorporated B. Open/Under Review Agency/Company/Reviewer C. Evaluated/Not Incorporated D. Beyond Scope/Not Evaluated Robert O'Brien E. Clarify or discuss Submittal Date: 7/26/2016 X. Comment closed Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) 1 O'Brien Hydraulic Report I need the information for the orifice structure to be in the WWHM A screenshot for the proposed notches from WWHM printed portion of the report in your appendix to verify. On that note has been included at the end of the WWHM Report the galvanized wire mesh being used will it extend to elevation within the Stormwater Site Plan. The notch 143.85? This would be good to note in the report as a means of dimensions are provided within the figures. Detail 6 A RO on sheet C3.0 has been revised to show a cross- preventing clogging of the small orifices being used. Also I think this section of the proposed wire mesh, aluminized metal feature should be aluminized metal and not galvanized (zinc leaching). has been referenced. 2 O'Brien Hydraulic Report In your WWHM model you are creating a larger pond (impervious The net impervious created from the rise of water area), this net new impervious area should be reflected in the model. surface is only 87 SF (0.002 AC) and was therefore In the report you stated an existing pond impervious area of 1.51 Ac, considered negligible within the impervious area A RO whatever the net pond increase above this should be reflected in consideration. model. 3 O'Brien Drainage Plan The driveway leading to the bay filter is pretty steep with a shallow and An extruded curb will be provided at the end of the wide flow spread (I am assuming from looking at detail), the inlet roadway to direct the road runoff towards the provided by the bay filter may not provide enough interception of flow Bayfilter. to capture the runoff. A couple options may be to provide grading and A RO curb at end of street to intercept and route bypassed flows to bay filter, or to provide a upstream catch basin to intercept runoff and do inlet analysis calculation for Q bypass. 4 O'Brien Drainage Plan Update note number 2 on the drainage plan to state treatment The note has been revised. A RO performed by proposed bay filter facility and not existing swale. 5 O'Brien Hydraulic Report Update predeveloped basin exhibit to be 0.72 Ac and not 0.79 Ac (or The existing basin map has been updated to 0.72 Ac. A RO verify which is correct). 6 O'Brien Hydraulic Report Model just the Phase 1 improvements. The weir may have to be The model has been revised to only include the phased or changed as improvements progress. The current design Phase 1 improvements. Refer to the revised expects an increase of runoff from 1.89 Ac of converted forest. If the drainage report for more information. A RO actual system sees less (during phase 1), then the net increase from Phase 1 activities would just run through the system without being detained. 7 Update to 2012 DOE manual requirements. The drainage report has been updated to O'Brien Hydraulic Report A RO reference the 2012 DOE manual requirements. 8 Update figure 2.2 to show greater than 5,000 sf of new impervious. The figure has been revised to show greater than O'Brien Hydraulic Report A RO 5,000 SF of new impervious. Comment Final Dwg No. Specification Correction Disposition Item No. Reviewer or Reference Review Comment Response Verification Page No. Chapter/Section Code (initials) 9 The WWHM ahs a sketched in pond element, but your SSD table seems off, I would expect the Area to be increasing as elevation The WWHM has been revised to use a SSD that O'Brien Hydraulic Report rises? I would recommend using CAD and just inputting your areas in better represents the stage and storage values of the A RO to the SSD table starting from top of pond surface up to your overflow existing pond. elevation. 12/22/25, 2:57 PM FW: Portage Bay BayFilter - Raelynn Jones - Outlook Outlook FW: Portage Bay BayFilter From Marc Hayes <mhayes@arlingtonwa.gov> Date Fri 7/29/2016 9:15 AM To Launa Peterson <lpeterson@arlingtonwa.gov>; Kristin Foster <kfoster@arlingtonwa.gov> 2 attachments (670 KB) Portage Bay Letter 7-27-16.pdf; BAYFILTERbaysaverGULDEnhanced CULD.pdf; Please include these in the Portage Creek file also. Thanks. From: Santhosh Moolayil [mailto:santhosh@insightengineering.net] Sent: Friday, July 29, 2016 8:36 AM To: Marc Hayes <mhayes@arlingtonwa.gov>; Amy Rusko <arusko@arlingtonwa.gov> Cc: Kristin Foster <kfoster@arlingtonwa.gov> Subject: FW: Portage Bay BayFilter Marc, Here is the letter from the Bayï¬lter guys. Sentence of the day: In God we trust, rest strictly cash. Best Regards, Santhosh J. Moolayil IECO 2804 Grand Ave. Suite-308 Everett, WA-98206 425-303-9363 425-303-9362 (Fax) www.insightengineering.net about:blank?windowId=SecondaryReadingPane2 1/1 From: Nova Heaton To: Kristin Foster; Launa Peterson; Kevin Olander; Gary Schlagel Subject: Portage Creek Homes Date: Tuesday, March 27, 2018 8:57:36 AM Kristin, Can you communicate the following to Mr. Brockway; I have talked to the PW water department and our building department about the project, here are current outstanding items and answers to your questions; Â· The interior plumbing may be inspected only if the meter is set for the house. Currently one meter is set, therefore one house can be inspected. In order to inspect the second house a second meter needs to be set. No cross plumbing is allowed. Â· No Certificate of Occupancy will be issued until all inspection and punch list items have been completed and fees have been paid. Â· The meter boxes need to be a minimum of three feet from the wing of the driveway as discussed yesterday. Please refer to W-070 of the City of Arlington standard plans. Please contact the water department to coordinate the movement of those boxes and lines. A water department representative shall be present during the process. The contractor will be made to dig up the work if a water department representative is not present. Â· Crushed surfacing top course must be brought in to fill the existing road cuts to stabilize the trenches immediately. The current situation is a traffic hazard and must be corrected. Â· Prior to placing the HMA patch, the existing asphalt will need to be saw cut to a neat and clean edge and the CSTC shall be placed and compacted to min 95% density. HMA shall not be installed in weather that may have a negative impact on the quality of the product. Â· A pile of excavated material is currently located within the City of Arlington right of way. This material must be moved outside the city right of way, and stabilized for erosion and sediment control. Â· The open ditch must be properly covered with a steel plate to protect the public. Please let me know if you have any further questions. Thank you, Nova Nova Heaton, P.E. - Development Services Manager nheaton@arlingtonwa.gov Phone 360.403.3437 City of Arlington - Community and Economic Development 18204 59th Ave NE Arlington Wa 98223 www.arlingtonwa.gov From: Nova Heaton To: Randy Brockway Cc: Kristin Foster; Kevin Olander; Launa Peterson Subject: RE: [External] - Re: Portage Creek - Items to be addressed Date: Monday, April 9, 2018 8:36:57 AM Thank you Randy, I appreciate your diligence in this matter. Nova From: Randy Brockway [mailto:randybrockway@yahoo.com] Sent: Monday, April 09, 2018 8:36 AM To: Nova Heaton <NHeaton@arlingtonwa.gov> Cc: Kristin Foster <kfoster@arlingtonwa.gov>; Kevin Olander <kolander@arlingtonwa.gov>; Launa Peterson <lpeterson@arlingtonwa.gov> Subject: Re: [External] - Re: Portage Creek - Items to be addressed Good Morning Nova, I spoke with my excavation contractor and he is going start taking care of all the issues you mentioned in your email later today or tomorrow at the latest. I believe he should be able to take care of everything in a couple days. I will be on site everyday this week to make sure everything is corrected as you mentioned. Thank you ! Randy Brockway Cell-206-992-5051 On Friday, April 6, 2018 2:31 PM, Nova Heaton <NHeaton@arlingtonwa.gov> wrote: Good Afternoon Randy, I am following up on our discussion on 3/27/18 and checking in on your progress. I was out looking at the site this afternoon as part of my review of the as-built drawings. It looks like you were not able to get your dirt work contractor out there this week as planned. There are several issues onsite that need your immediate attention. I have attached a couple of photos to help illustrate the issues. Â· Images 1155 and 1156 show the hazard next to the sidewalk near the intersection. This must be covered with a steel plate or filled in. Plywood, which was not covering the hole at the time I was out there, is not sufficient protection. Â· Images 1151, 1152, and 1153 show the existing roadway cuts. The gravel shall be made flush with the roadway surface, or some other method of stabilizing and filling the roadway cuts shall be put in place until final paving can be done. Â· Image 1154 shows the access road, exposed soils, and amount of mud track out onto the roadway. This site must be stabilized for erosion and sediment control. Temporary inserts in the roadway catch basins have been modified (holes cut in the fabric) so they are no longer protecting the system from siltation. The road surface must be cleaned, storm drain inlet protection devices must be removed and replaced, exposed soils must be covered or planted, the temporary construction access must be re-established to prevent further track out onto the road. These are the minimum measures that must be taken at this time. Please work with your CESCL to stabilize the site appropriately. The City of Arlington is requesting you take immediate action to voluntarily correct these violations. Failure to do so shall result in a code enforcement action pursuant with AMC 11.01.080. Code enforcement actions will result in fines, please correct the above issues so this can be avoided. Please provide the date I should expect these issues to be resolved by. Thank you, Nova From: Randy Brockway [mailto:randybrockway@yahoo.com] Sent: Tuesday, March 27, 2018 1:15 PM To: Nova Heaton <NHeaton@arlingtonwa.gov> Cc: Kristin Foster <kfoster@arlingtonwa.gov>; Kevin Olander <kolander@arlingtonwa.gov>; Launa Peterson <lpeterson@arlingtonwa.gov> Subject: [External] - Re: Portage Creek - Items to be addressed Nova Thank you again for getting that list to me, it gives me what I needed to understand how to move this project forward I will keep you posted on my progress. I appreciate everyoneâ€™s help there ! Randy 206-992-5051 Sent from my iPhone On Mar 27, 2018, at 12:01 PM, Nova Heaton <NHeaton@arlingtonwa.gov> wrote: Randy, Following up our earlier conversation regarding the necessary requirements for issuance of the next 2 building permits; Â· All requirements listed in the previous email must be completed Â· Storm, water, and sewer must be in to each lot requesting a building permit Â· As-built drawings must be completed and approved for the civil work Â· The new access road must be stabilized (place and compact base and crushed surfacing) Â· Water meters for each building must be set, contact water department Â· Temporary erosion and sediment control on the site must be updated to meet minimum standards. (IE; no track out from site, no silty water leaving the site, cover or stabilize onsite soils and stockpiled materials) Kevin and I will be out to look at the civil work and compare it to the as- built drawings sometime this week. Please focus on getting the TESC measures up to standards as soon as possible, we expect the site to be maintained in a neat and clean manner throughout the building process. Thank you, and feel free to contact me if you have additional questions or need clarification. Nova Nova Heaton, P.E. - Development Services Manager nheaton@arlingtonwa.gov Phone 360.403.3437 City of Arlington - Community and Economic Development 18204 59th Ave NE Arlington Wa 98223 www.arlingtonwa.gov From: Kristin Foster Sent: Tuesday, March 27, 2018 11:49 AM To: randybrockway@yahoo.com Cc: Nova Heaton <NHeaton@arlingtonwa.gov>; Kevin Olander <kolander@arlingtonwa.gov>; Launa Peterson <lpeterson@arlingtonwa.gov> Subject: Portage Creek - Items to be addressed Randy, Nova has communicated with the PW water department and our building department about the project, here are current outstanding items and answers to your questions; The interior plumbing may be inspected only if the meter is set for the house. Currently one meter is set, therefore one house can be inspected. In order to inspect the second house a second meter needs to be set. No cross plumbing is allowed. No Certificate of Occupancy will be issued until all inspection and punch list items have been completed and fees have been paid. The meter boxes need to be a minimum of three feet from the wing of the driveway as discussed yesterday. Please refer to W-070 of the City of Arlington standard plans. Please contact the water department to coordinate the movement of those boxes and lines. A water department representative shall be present during the process. The contractor will be made to dig up the work if a water department representative is not present. Crushed surfacing top course must be brought in to fill the existing road cuts to stabilize the trenches immediately. The current situation is a traffic hazard and must be corrected. Prior to placing the HMA patch, the existing asphalt will need to be saw cut to a neat and clean edge and the CSTC shall be placed and compacted to min 95% density. HMA shall not be installed in weather that may have a negative impact on the quality of the product. A pile of excavated material is currently located within the City of Arlington right of way. This material must be moved outside the city right of way, and stabilized for erosion and sediment control. The open ditch must be properly covered with a steel plate to protect the public. Let me know if you have any questions. Thanks, Kristin Foster Permit Technician City of Arlington 18204 59th Ave NE Arlington, WA 98223 360 403 3549 kfoster@arlingtonwa.gov From: Robert O"Brien To: Launa Peterson; Marc Hayes Cc: Kristin Foster Subject: RE: Portage Creek Estates Date: Monday, July 11, 2016 2:20:18 PM Attachments: image001.jpg image002.png Launa and Marc, Here is my initial estimate on time to complete Portage Creek Estates Plan. How do you want me to handle AECOM comment/responses? I did not account for that in this estimate. Rob Robert Bill Portage Creek Estates O'Brien Jordan Fee Task Review Civil Plans 1 0 $135.00 Review Drainage Report 2 0 $270.00 Run WWHM Model 1 0 $135.00 Review SWPPP 1 0 $135.00 Review Maintenance Manual 0 0 $0.00 QA/QC 0 1 $135.00 Total 5 1 $810.00 From: Launa Peterson [mailto:lpeterson@arlingtonwa.gov] Sent: Friday, July 8, 2016 8:22 AM To: Robert O'Brien <roberto@oneillsg.com> Cc: Kristin Foster <kfoster@arlingtonwa.gov>; Marc Hayes <mhayes@arlingtonwa.gov> Subject: Portage Creek Estates Good morning Rob, I understand that you received Portage Creek Estates yesterday for review. If possible, we would like review comments by 7-21-2016, let me know if this does not work for you. Additionally, I need to have a quote from you on this one so the city can be reimbursed for this review. Thank you and have a great weekend! Launa Peterson, CPT| City of Arlington 360-403-3551 | lpeterson@arlingtonwa.gov 18204 59th Avenue NE, Arlington, WA 98223 (located inside the Airport Office Building) The Arlington / Darrington community has been selected as a finalist in the nationwide Americaâ€™s Best Communities competition. Read more here, and like our ABC Facebook page From: Richard Karns To: Randy Brockway Cc: Amy Rusko; Marc Hayes; Launa Peterson; Kristin Foster; Kevin Olander Subject: RE: Portage Creek Date: Tuesday, February 28, 2017 2:28:48 PM Attachments: image001.jpg image002.png image003.jpg Hi Randy, I donâ€™t think we have met yet, Richard Karns here, I took Chris Youngâ€™s position. To answer your question on the soil bearing requirement for geo-testing please hold off until you have design review approvals. This has been a very wet February and I donâ€™t want to have you open up the ground while we are still in the mist of all this rain. The soils are acting as a pre-load in their current placement. Once the designs have been approved, March 23, 2017, that would be the time to open up the ground and test for bearing capacity. I would suggest that you do one or two at a time as the site is so tight and depending on your strategy to open them all would hinder productivity. Nashâ€™s design calls for a minimum of 1500psi for the foundations, which is a minimum code requirement, listed on your plan sets. Any other questions please feel free to contact me. Richard Karns, CBO Building Official City of Arlington 18204 59th DR NE (360) 403-3432 rkarns@arlingtonwa.gov From: Randy Brockway [mailto:randybrockway@yahoo.com] Sent: Tuesday, February 28, 2017 12:05 PM To: Launa Peterson <lpeterson@arlingtonwa.gov> Cc: Richard Karns <rkarns@arlingtonwa.gov>; Marc Hayes <mhayes@arlingtonwa.gov>; Kevin Olander <kolander@arlingtonwa.gov>; Kristin Foster <kfoster@arlingtonwa.gov>; Amy Rusko <arusko@arlingtonwa.gov> Subject: Re: Portage Creek Hi Launa, I don't know the history of the site but the fill material does not surprise me. I agree and had planned on getting a geo tech to check on the soils for each site for compaction and soil bearing before pouring the foundation footings, but to do this we would need to excavate the foundation hole first. Please let me know if this is what you wanted ? Thank-you Randy Brockway Cell-206-992-5051 On Tuesday, February 28, 2017 11:26 AM, Launa Peterson <lpeterson@arlingtonwa.gov> wrote: Good morning Randy, It has been observed that there has been fill material placed on the proposed building sites. Due to this occurrence a Geotechnical Report is required to address each of the building sites for structural material and density to support the dwelling units. The Design Review submittal is for Phase 1 which is the first 6 houses. Additional Design Review will be required for additional phases. Launa Peterson, CPT| City of Arlington 360-403-3551 | lpeterson@arlingtonwa.gov 18204 59th Avenue NE, Arlington, WA 98223 (located inside the Airport Office Building) The Arlington / Darrington community has been selected as a finalist in the nationwide Americaâ€™s Best Communities competition. Read more here, and like our ABC Facebook page FIGURE 2. VICINITY MAP SITE TAKEN FROM THE BING MAPS Figure 2 -Vicinity Map Portage Creek Arlington, Washington SCALE: DATE: 10/5/15 JOB #: 15-0740 P.O. Box 1478 Everett, WA 98206 NTS 425-303-9363, 425-303-9362 f. FILE NAME: Info@insightengineering.net BY: JDM 15-0740 /doc/Stormwater Site Plan From: James Kelly To: Eric Scott Cc: Amy Rusko; Launa Peterson; Christopher Young; Troy Davis; Paul Ellis; Marc Hayes Subject: RE: Lavoy Development on 207th St Date: Thursday, February 7, 2013 7:29:02 AM Attachments: image001.png image002.png image003.png image004.png Eric â€“ As we discussed: 1. There is no water or sewer in front of those lots; there may be pipes in the ground but the City never accepted the utilities. 2. Though the property may have been dedicated and deeded to the City, I do not believe the City ever accepted the road or any of the infrastructure improvements. 3. This area appears to be extremely unstable, I donâ€™t know if this request would ever make it through Land Use permitting without a geotechnical report attesting to the geological stability of the land. Jim From: Eric Scott Sent: Thursday, January 17, 2013 1:29 PM To: James Kelly; Paul Ellis; Marc Hayes Cc: Amy Rusko; Launa Peterson; Christopher Young; Troy Davis Subject: Lavoy Development on 207th St The developer for the Lavoy property on 207th wants to build a duplex on Lot 1, as shown in the attached plat. I visited the site and it appears that 207th has significant damage to it from the sliding hillside on Lot 3. The pavement and sidewalks have buckled and I assume there is damage to the underground utilities on the south side. It also appears that the dedication of the roadway was finalized sometime in the past, so the City owns the road. Were there any previous conversations about what to do about the failed roadway? I seem to remember something about vacating the road back to the developer. If Lot 1 is to be developed, then I presume they will want a functioning roadway to access Lot 1. Since it was a slide issue on Lot 3 that damaged the public roadway, I believe the lot owner is responsible for repairing the roadway and stabilizing the hillside prior to development of other lots. Let me know what you know so we can address the application when it comes in. Thanks Eric Eric J. Scott, PE City Engineer City of Arlington 238 N. Olympic Ave. Arlington, WA 98223 Dir: 360-403-3512 Fax: 360-403-3418 EScott@arlingtonwa.gov