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DRAINAGE REPORT.pdfM Date Prepared: June 30, 2014 Site Address: 9332232 nd St. S.W. Edmonds, WA 98020 Tax Parcel No: 270336-001-096-00 Donna L Breske PE, LLC 6621 Foster Slough Road Snohomish, WA 98290 Phone: (425)334-9980 Mobile: (206)715-9582 Email: donnabreske@comcast.net 13EVELOPMENT SERVICES 6-30-14 Table of Contents ExecutiveSummary......................................................................................................................................... I VicinityMap.................................................................................................................................................... 2 ProjectClassification Flow Chart.................................................................................................................... 3 Minimum Requirement #1: Preparation of a Stormwater Site Plan.............................................................4-5 Minimum Requirement #2: Stormwater Pollution Prevention Plan................................................................ 6 Minimum Requirement #3: Water Pollution Source Control for New Development ..................................... 6 Minimum Requirement #4: Natural Drainage Systems and Outfalls.............................................................. 6 Minimum Requirement #5: On -Site Stormwater Management..................................................................... 6 Minimum Requirement #6: Runoff Treatment............................................................................................... 6 Minimum Requirement #7: Flow Control...................................................................................................6-7 Minimum Requirement #8: Wetland Protection............................................................................................. 7 Minimum Requirement #9: Operation and Maintenance............................................................................... 7 Minimum Requirement #10: Offsite Analysis and Mitigation........................................................................ 7 Minimum Requirement #11: Financial Liability............................................................................................. 7 Appendix A: Storm Tech SC -310 Infiltration Chamber Sizing for North Infiltration System..................8-16 Appendix B: Storm Tech SC -740 Infiltration Chamber Sizing for South Infiltration System................17-25 Appendix C: Supporting Documents from Liu & Associates Geotechnical Report.............................26-34 Appendix D: Soil Management Exhibit...................................................................................................35-36 Appendix E: Opeirations & Maintenance Sheets....................................................................................37-40 Jay Young 4 -lot Shot Plat, 9332 232°d ST. S.W., Edmonds, WA Drainage Report for Jay Young 4 -Lot Short Plat 9332232 nd St. S. NT Edmonds, WA 98020 Executive Summary This Jay Young 4 -Lot Short Plat Drainage Report and Plan Sheets propose the creation of 4 -lots from one tax parcel. The existing Tax Parcel has one duplex unit currently on site, that is proposed to remain as Lot 1 of the proposed 4 -lots. The total area of the site is 1.08 Acres. The existing site conditions include a large amount of mature evergreen trees, lawn, a duplex and driveway. The site slopes downward to the south with slopes ranging from 2% - 24%. Only a small portion of the site, located along the east boundary, is in the range of 24% slope. The project is within the Edmonds Way Drainage Basin Basin. Scope of work for this project includes; BMP implementation, clearing and grubbing, installation of Storm Tech Infiltration chambers, catch basins and piping, and underground utilities. A 20 -foot wide shared access easement will provide access to 232°d St. S.W., the same point of access now used for the duplex. There are two infiltration systems proposed to be installed, a north system and a south system. The systems have been sized using the WWHM2012 program and the infiltration rates are based upon soil sample testing provided within a Liu & Associates Geotechnical Report. The 12 Elements of Stormwater Pollution Prevention (SWPP) are addressed on the TESC and Clearing plan sheet. Mechanisms for utilizing the twelve SWPP Elements include; silt fences, plastic covering, temporary and permanent seeding, and inlet protection. Per Edmonds Stormwater Supplement Figure 2-1 titled Project Classification, Category 2 Small Site Project Minimum Requirements #1 - #11 must be fulfilled in the design of this proj ect. The requirement for water quality is triggered for this project since more than 5,000 square feet of new PGIS is proposed. A bioswale is proposed to be installed above the north infiltration chamber system. 1 PREPARED BY.- DONNA Y:DONNA L BRESKE PE, LLC 6621 FOSTER SLOUGH RD. SNOHOMISH, WA 98290 PHONE: (425) 334-9980 DonnoBreske@comcost.net 17ICINIT17 MAP FOR JAY YOUNG 4 -LOT SSP SITE ADDRES: 9,332 232ND ST. SW, EDMONDS, WA DATE: 06-30-2014 APRlL2010 Start Does the project involve 1 - acre or more of land disturbing activity? Is the project part of a larger common plan of development or sale where the total disturbed area for the entire plan will total 1 -acre or more ofland-disturbing activity? No EJ VO\IDSSTCkRMATERCODESUPFLEMENT Figure 2-1: Project Classification Yes Do Large Site Project: Read Chapter 3 and see Chapter 4 for Yes requirements Does the Project involve one or more of the Yes following: 2,000 square feet or more of new impervious surface, replaced impervious surface or new plus replaced impervious surface? OR 7,000 square feet of land -disturbing activity? OR 50 cubic yards or more of either grading, fill, or excavation as defined in Chapter 18.40.000 ECDC? No Minor Site Project: Read Chapter 3 and see Chapter 6 for requirements Does the project create or add 5,000 square feet of new impervious surface, replaced impervious surface or new plus replaced impervious surface? OR Convert'/, acre or more of native vegetation: to lawn or landscaped area OR Through a combination of creating effective impervious srnface and converted pervious surfaces, causes an increase of 0,1 cubic feet per second in the 100 -year flow frequency from a threshold discharge area as estimated using an approved model? No I ( Yes Category 1 Small Site Project: Read Chapter 3 and see Chapter 5 for requirements 1 Assumes the project in question meets applicability requirements of ECDC 18.30.030. 2 Small Site Project: Read Chapter 3 and see Chapter 5 for requirements 3 of 0"„r,z'000W ,,..rc.>.� 2,OCtASSItYINGPROJECTS Jay Young 4 -Lot Short Plat 9332 218'x' St. S. TV, Edmonds, WA Edmonds Stormwater Code Supplement Small Site requirements #1411: Small Site Minimum Requirement #1: Preparation of a Stormwater Site Plan, Steps 1-7 ESWCS Section 5.1 Step 1: Collect and Analyze Information on Existing Conditions. This Engineer, Donna L. Breske, P.E. visited the site on April 23, 2014 and observed the following a. The aerial view of the site in Google Earth was congruent to the site visit. b. No wet areas were present on the site. c. The site slopes downward to the lout property line of the site. d. The site has slopes ranging from slopes of 2% to 24% e. The four excavated soil test pits discussed in the Liu & Assoc. Geotecnical Report were observed. ® A boundary and topographic survey was provided by LSA. Infor-rnation obtained from this map includes parcel boundary and bearings, topography, and existing features including a duplex. ® THE BELOW ELEMENTS WERE HARMONIZED INTO THE DESIGN FROM THE GEOTEC REPORT PREPARED BY LIU & ASSOCIATES, JUNE 1, 2014: 1. Three soil samples, one from each of Test Pits 2, 3 and 4, were obtained from either recessional outwash overlying the till deposit or advance outwash underlying the till deposit under the project site and taken to HWA laboratory for Particle Size Distribution tests to determine their infiltration rates. Based on these test results, Stormwater collected over impervious surfaces of the development may be disposed onsite by infiltration into the outwash deposits. 2. The bottom of infiltration ponds or infiltration trenches should be excavated at least 6 inches into the target soil layers from which the soil samples were obtained. 3. Stormwater captured over paved driveways should be routed into a catch basin equipped with an oil -water separator before being released into the infiltration trenches Step 2: Prepared Preliminary Development Layout ® This Engineer, Donna L. Breske, combined the information from the boundary survey, existing conditions, Edmonds Stormwater Code Supplement Requirements, Edmonds Community Development Code requirements for subdivision and Department of Ecology's Stormwater to create an overall site plan. ® Additionally a meeting was held on May 30, 2014, with this Engineer, the client Jay Young and City Staff members, Kernen Lien, Jeanie McConnel, and Shane Hope to verify the Short Plat and access easement requirements. F. Jay Young 4 -Lot Short Plat 9332 218`x' St. S. TV, Edmonds, PVA Step 3: Perform Off -Site Upstream and Downstream Analysis. ® An offsite upstream and downstream analysis was deduced from the February 21, 2014 site visit, USGS data, and SnoScapes. ® Per the City of Edmonds Basin Map, the project is located in the Edmonds Way Drainage Basin, Upstream Analysis: A single family home is located upstream of the site. Said home is on a relatively flat lot and no significant run-on onto the site is anticipated. Downstream Analysis: The low part of the site, (the south property line), is located in a localized depression. The south infiltration system is proposed to be located adjacent to the south property line. New rooftops and paved surfaces are proposed to be routed to infiltration systems. Little, if any runoff is expected to sheet flow to the south portion of the site, and if it does it is expected to dispersed into the topsoil layer. Step 4: Determine Applicable Small Site Minimum Requirements. ® Minimum Requirements #1411 are applicable as follows: Because the proposed project results in more than 5,000 SF of net new impervious area but less than 1 -acre of land disturbing activity, City of Edmonds Stormwater Code Supplement's Category 2 Small Site Minimum Requirements #I - #11 apply to this drainage plan. Step 5: Prepare a Permanent Stormwater Control Plan ® A Permanent Stormwater Control Plan is included within the titled Road and Drainage Plan Sheet. Specific design elements on the plan sheet include; sloped shared access road, catch basins, piping system, bioswale, and infiltration systems. Step 6: Prepare a Stormwater Pollution Prevention Plan (SWPPP) ® The 12 Elements of the SWPP are shown on the TESC and Clearing Plan Sheet. Step 7: Complete the Stormwater Site Plan A Permanent Stormwater Site Plan signed by Donna L. Breske, P.E. is included in the submittal for this project. The new NPGIS and PGIS will be conveyed to the on-site infiltration system. Jay Young 4 -Lot Short Plat 9332218 1h St. S. W., Edmonds, WA Small Site Minimum Requirement 2: Contruction Stormwater Pollution Prevention Plan ESWCS 5.2 SWPP elements are included on the TESC and Grading Plan Sheet. Small Site Minimum Requirement 3: Source Control of Pollutants ESWCS 5.3 Oil/Water Separators are proposed within CB's for runoff from PGIS. Small Site Minimum Requirement 4: Preservation of Natural Drainage Systems and Outfalls ESWCS 5.4 Flows from the site will re -charge the hydrology via the infiltration systems. Small Site Minimum Requirement 5: On -Site Stormwater Management ESWCS 5.5 Small Site Minimum Requirement #5 requires that stormwater is infiltrated, retained, or dispersed on-site to the maximum extent feasible without causing flooding or erosion impacts, and to reduce hydrologic disruption to the maximum extent feasible. In accordance with this requirement, on-site infiltration is proposed for the new impervious areas including the new paved driveway to the duplex. The rooftop runoff from the duplex will remain unchanged. Small Site Minimum Requirement 6: Runoff Treatment ESWCS 5.6 Runoff treatment for the proposed 7,800 sf +/- sf PGIS flows entering the north infiltration system will fast be routed through a bioswale. Since the PGIS area routed to the south infiltration chamber is less than 5,000 square feet, there is no water quality proposed for said runoff. Small Site Minimum Requirement 7: Flow Control ESWCS 5.7 Per the City of Edmonds Stormwater Supplement Figure 2-1 titled Project Classification, Category 2 Small Site Project Minimum Requirements must be fulfilled in the design of this project. 0 Jay Young 4 -Lot Short Plat 9332 218" St. S. W., Edmonds, WA There are two infiltration systems proposed to be installed, a north system and a south system. The systems have been sized using the W WHM2012 program and the infiltration rates are based upon soil sample testing provided within a Liu & Associates Geotechnical Report and included within an Appendix in this report. Small Site Minimum Requirement 8: Wetland Protection ESWCS 5.8 There are no wetlands on-site. Small Site Minimum Requirement 9: Operation and Maintenance ESWCS 5.9 This project proposes the installation of Type 2 Catch Basins, and two infiltration systems. Maintenance sheets for these items are included in the Appendix portion of this report. Small Site Minimum Requirement 10: Offsite Analysis and Mitigation ESWCS 5.10 The drainage pattern of the site will remain unchanged. Flows will continue to be contained on site via the infiltration systems just as they are basically now contained on site due to the topography and localized depression along the south property line. Requirement 11: Financial Liability ESWCS 5.11 A performance bond will be issued at time of construction. MMUDIZIM 4 6l'l+`I YIA�t l PREPARED BY.• DONNA L BRESKE PE, LLC 6621 FOSTER SLOUGH RD. SNOHOMISH, WA 98290 PHONE. (425) 334-9980 DonnaBreske@comcast.net MEIN AREA TO BE ROUTED TO BIOSWALE EASEMENT WITH STORMTECH INFILTRATION TRENCH BENEATH. PCIS. (DRIVING SURFACE) 5,540 1,200 1,100 7,840 SF (0.18 Ac) NPGIS. (ROOFTOP FROM LOT 2) 3,600 SF (0.083 Ac) LOT 4 t�lp>L e LOT 1 20' BIOSWALE & INFILTRA77ON TRENCH EASEMENT FOR STORY WATER RUNOFF FROM ACCESS ROAD & LOT 2 "&o os� LOT 2 LOT 3 60' 0 60' SCALE: 1" = 60' IMPERVIOUS EXHIBIT "A" FOR JAY YOUNG 4 -LOT SP SITE ADDRES: 9332 232ND ST. SW, EDMONDS, WA SCALE: 1 " = 60' DATE. 06-11-2014 FIGURE. 1 of 1 JAY YOUNG 4 -LOT SHORT PLAT STORM TECH INFILTRATION SYSTEM Downstream Connect -ions r Pfecipitatioll Applied,to Faciltly r Evap ration Applied to Facility Faciffity Dimensions Facility Bottom Elevation (ft) Bottom Length (ft) 184 B ottorfj Width (ft) &6 Effective D epth (I t) Left Side Slope (H. f) Bottom Side Slope. [HA i] BILI Hight Side S lope (H At) -H Top Side Slope (HN) Infiltration Nieasure-d I nflitfation Rate (inihr) Fo� Reduction Factorfinf ilt"f actor) Use Wetted S uiface Area (sidev-jalls) FN—O— Total Volume Infiltrated (ac -ft) 31.421 T otal Volume Through R 1---ef (ac -ft) 0 T otal Volume T hrough Facility (ac. -ft) 31.42 Percent Infiltrated 100 —Auto Pond Canck F)onq Facility Dimension Diagram Outlet Structure Data Riser Height (ft) Fj— tj Riser Diameter [in) ri Riser Type FFIatJ1 Notch Type Orifice Diameter Height Number (In) (10 Pond Volume at R is-er Head (ac. -ft) .019 Show Pond Table i6pen' Table USE TWO RUNS OF STORM TECH SC -310 CHAMBERS, EACH 84 -FEET LONG or THREE RUNS AT 56 -FEET LONG. 10 BILI -H Pond Volume at R is-er Head (ac. -ft) .019 Show Pond Table i6pen' Table USE TWO RUNS OF STORM TECH SC -310 CHAMBERS, EACH 84 -FEET LONG or THREE RUNS AT 56 -FEET LONG. 10 ITWMI i1' Designed to meet the most stringent industry performance standards for superior structural integrity while providing designers with a cost-effective method to save valuable land and protect water resources. The StormTech system is designed primarily to be used under parking lots thus maximizing land usage for commerce1 and municipal applications. StormTech SC -310 C (not to scale) Nominal Chamber Sp Size (L x W x H) 85.4° x 34.0° x 16.0" (2170 x 864 x 406 mm Chamber Storage 14.7 ft3 (0.42 m3) Minimum Installed St{ 31.0 ft' (0.88 m3) Weight 37.0 lbs (16.8 kg) Shipping 41 chambers/pallet 108 end caps/pallet 18 pallets/truck Typical Cross Section Detail (not to scale) _6" (150 mm) DIA. MAX SC -310 End Cap 16.0" (40�m)/ / \ 34.0" (864 mm)-., THE INSTALLED CHAMBER SYSTEM SHALL PROVIDE THE LOAD FACTORS SPECIFIED IN THE AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND LIVE LOADS, WITH CONSIDERATION FOR IMPACT AND MULTIPLE VEHICLE PRESENCE. SC -310 CHAMBER 3/4 - 2 -INCH CLEAN, CRUSHED. ANGULAR STONE AASHTO N1288 CLASS 2 'T NON -WOVEN GEOTEXTILE -, (GJUV IIIIiiI SC -310 Chamber 85.4" (2170 mm) INSTALLED----------� I{ w I, �lul�' ( �', �Ei `�frj° I_iH_ ���� �� � li �(l� nll� i�LJ���✓-���i `�,'.l��ill CHAMBERS SHALLMEETASTM F 2922-12 "STANDARD SPECIFICATION FOR POLYETHYLENE (PE) CORRUGATED WALL STORM WATER COLLECTION CHAMBERS." GRANULAR WELL GRADED SOIUAGGREGATE MIXTURES, <35/ FINES. COMPACT IN 61N LIFTS T095%PROCTOR DENSITY, DESIGN ENGINEER IS RESPONSIBLE FOR 6'(-150 mm) MIN, —} --{-34' (864 mm) I {— 12'(305 mm) MIN. TYP. ENSURING THE REQUIRED BEARING CAPACITY OF SUBGRADE SOILS' THIS CROSS SECTION DETAILS THE REQUIREMENTS NECESSARY TO SATISFY THE LOAD FACTORS SPECIFIED IN THE AASHTO _RFD BRIDGE DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND LIVE LOADS USING STORNITECH CHMABERS SEETHE TABLE OF ACCEPTABLE FILL MATERIALS. SC -310 END CAP r PAVEMENT as ura1E1I l raueT— 1-1 ,_"IO FROM En�CLE311 VOCCUii _ 96` 11cr CODER TO 1401ES 18" (460 mm) (2440 mm) MIN. MAX. 6,(150 mm) MIN. 4 IO 16' (406 mm) DEPTH TO BE DETERMINED BY DESIGN ENGINEER _ — I 6'(150 mm)MIN. DESIGN ENGINEER IS RESPONSIBLE FOR 6'(-150 mm) MIN, —} --{-34' (864 mm) I {— 12'(305 mm) MIN. TYP. ENSURING THE REQUIRED BEARING CAPACITY OF SUBGRADE SOILS' THIS CROSS SECTION DETAILS THE REQUIREMENTS NECESSARY TO SATISFY THE LOAD FACTORS SPECIFIED IN THE AASHTO _RFD BRIDGE DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND LIVE LOADS USING STORNITECH CHMABERS SC -310 Cumulative Storage Volumes Per Chamber Assumes 40% Stone Porosity. Calculations are Based Upon a 6" (152 mm) Stone Base Under the Chambers. 1. )t: r ,r• 28 (711} ^14.70 (0.416 ' r ;r• 31.00 (0.878) 27 (686) 14.70 (0.416) 30.21 (0.855)___ 26 (680) Stone 14.70 (0.416) 25 (610) Cover 14.70 (0.416) 29.42 (0.833)_ 28.63 (0.811) 1 014.70 (0.416) 27.84 (0.78859) ��2214.70 (0.416) 26.26 (0.748) -- -- 20 (508) 14.49 (0.410) 24.54 0.695) 19 (483) 14.22 (0.403) _ 23.58 (0.668) 18 (457) 13.68 (0.387) 22.47 (0.636) 17 (432) 12.99 (0.368) 21.25 (0.602) 16 (406) 12.17 (0.345) 19.97 0.566) C ___15 (381 - 11.25 (0.319) 14 (356) 10.23 (0.290) 18.62 (0.528) 17.22 (0.488) 13 (330) 9.15 (0.260) - 12 (305) _7.99 (0.227)_ -15.78 (0.44_7) - - 14.29 (0.425) 11 (279) 6.78 (0.192) 12.77 (0.362) _ 10 (254)- 5.51 (0.156) 11.22 (0.318) - 9 (229) 4.19 (0.119) 9.64 0.278) j C 8 (203) 2.83 (0.081) 8.03 (0.227) _ 7 (178)1.43 (0.041) � 6 (152) -_ �_ 0 6.40 (0.181) j (0.134)_-j 5 (127 - 0 4 (102) Stone Foundation 0 _4.74 3.95 (0.112) 3.16 (0.090) L_ 3 (76) - 0 2.37 (0.067) _2 (51 -� 0 1.58 (0.046) -1 1 (25) 0 0.79 (0.022) Note: Add 0.79 cu. ft. (0.022 m3) of storage for each additional inch (25 mm) of stone foundation. NOTE: THE EQUIVALENT DEPTH OF WATER IS 1 -FT FOR USE IN THE WWHM2012 INPUT FOR INFILTRATION STORAGE DEPTH. THIS EQUIVALENT 1 -FOOT DEPTH ACCOUNTS FOR THE 40% VOID SPACE OF THE ROCK BELOW AND ON THE SIDES OF THE STORM Storage Volume Per Chamber Bare Chamber and Stone j ! Chamber Stone Foundation Depth Storage in. (mm) ft3 (m3) 6 (150) 12 (305) 18 (460) StormTech SC 310 14.7 (0.4) --- 31.0 (0.9)35.7 --- (1.0) - 40.4 (1.1) Note: Storage volumes are in cubic feet per chamber. Assumes 40% porosity for the stone plus the chamber volume. Amount of Stone Per Chamber Stone Foundation Depth ENGLISH TONS (CUBIC YARDS) 6"1 12" j 18" StormTech SC -310 2.1 (1.5 yd3) j 2.7 (1.9 yd3) 3.4 (2.4 yd') METRIC KILOGRAMS (METERS) 150 mm I 305 mm 460 mm StormTech SC -310 1830 (1.1 m3) 2490 (1.5 m3) 2990 (1.8 m3) Note: Assumes 6'(150 mm) of stone above, and between chambers Volume of Excavation Per Chamber Stone Foundation Depth 6" (150 mm) 12" (305 mm) 18" (460 mm) StormTech SC -310 2.9 (2.2) 3.4 (2.6) 3.8 (2.9) Note: Volumes are in cubic yards (cubic meters) per chamber. Assumes 6" (150 mm) of separation between chamber rows and 18'(460 mm) of cover. The volume of excavation will vary as the depth of the cover increases. STANDARD LIMITED WARRANTY OF STORMTECH LLC ("STORMTECH"): PRODUCTS (A) This Limited Warranty applies solely to the StormTech chambers and endplates manufactured by StormTech and sold to the original purchaser (the 'Purchaser"). The chambers and endplates are collectively referred to as the "Products." (B) The structural integrity of the Products, when installed strictly in accordance with Storm-fech's written installation instructions at the time of installation, are warranted to the Purchaser against defective materials and workmanship for one (1) year from the date of purchase. Should a de- fect appear in the Limited Warranty period, the Purchaser shall provide StormTech with written notice of the alleged defect at StormTech's corporate headquarters within ten (10) days of the discovery of the defect. The notice shall describe the alleged defect in reasonable detail. StormTech agrees to supply replacements for those Products determined by StormTech to be defective and covered by this Limited Warranty. The supply of replacement products is the sole remedy of the Purchaser for breaches of this Limited Warranty. StormTech's liability specifically excludes the cost of removal and/or installation of the Products. (C) THIS LIMITED WARRANTY IS EXCLUSIVE. THERE ARE NO OTHER WARRANTIES WITH RESPECT TO THE PRODUCTS, INCLUDING NO IMPLIED WARRANTIES OF MERCHANT -ABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE. (D) This Limited Warranty only applies to the Products when the Products are installed in a single layer. UNDER NO CIRCUMSTANCES, SHALL THE PRODUCTS BE INSTALLED IN A MULTI -LAYER CONFIGURATION. (E) No representative of StormTech has the authority to change this Limited Warranty in any manner or to extend this Limited Warranty, This Limited Warranty does not apply to any person other than to the Purchaser. (F) Under no circumstances shall StormTech be liable to the Purchaser or to any third party for prod- uct liability claims; claims arising from the design, shipment, or installation of the Products, or the cost of other goods or services related to the purchase and installation of the Products. For this Limited Warranty to apply, the Products must be installed in accordance with all site condi- tions required by stale and local codes; all other applicable laws; and StormTech's written in- stallation instructions. (G) THE LIMITED WARRANTY DOES NOT EXTEND TO INCIDENTAL, CONSEQUENTIAL, SPE- CIAL OR INDIRECT DAMAGES. STORMTECH SHALL NOT BE LIABLE FOR PENALTIES OR LIQUIDATED DAMAGES, INCLUDING LOSS OF PRODUCTION AND PROFITS; LABOR AND MATERIALS; OVERHEAD COSTS; OR OTHER LOSS OR EXPENSE INCURRED BY THE PURCHASER OR ANY THIRD PARTY. SPECIFICALLY EXCLUDED FROM LIMITED WAR- RANTY COVERAGE ARE DAMAGE TO THE PRODUCTS ARISING FROM ORDINARY WEAR AND TEAR; ALTERATION, ACCIDENT, MISUSE, ABUSE OR NEGLECT; THE PRODUCTS BEING SUBJECTED TO VEHICLE TRAFFIC OR OTHER CONDITIONS WHICH ARE NOT PERMITTED BY STORMTECH'S WRITTEN SPECIFICATIONS OR INSTALLATION INSTRUC- TIONS; FAILURE TO MAINTAIN THE MINIMUM GROUND COVERS SET FORTH IN THE INSTALLATION INSTRUCTIONS; THE PLACEMENT OF IMPROPER MATERIALS INTO THE PRODUCTS; FAILURE OF THE PRODUCTS DUE TO IMPROPER SITING OR IMPROPER SIZING; OR ANYOTHER EVENT NOT CAUSED BY STORMTECH. THIS LIMITED WAR- RANTY REPRESENTS STORMTECH'S SOLE LIABILITY TO THE PURCHASER FOR CLAIMS RELATED TO THE PRODUCTS, WHETHER THE CLAIM IS BASED UPON CON- TRACT, TORT, OR OTHER LEGAL THEORY. 20 Beaver Road, Suite 104 Wethersfield I Connecticut 106109 12 860.529.8188 1888.892.2694 ( fax 866.328.8401 ( fax 860-529-8040 1 www.stormtech.com Printed in U.S.A. © Copyright. All rights reserved. StormTech LLC, 2007 Printed on recycled paper �1 S15-090508 WWHM2012 PROJECT REPORT Project Name: Jay Young Site Name: Jay Young 4 -lot Site Address: 9332 232nd ST SW City : Edmonds, WA Report Date: 6/11/2014 MGS Regoin Puget East Data Start 1948/10/01 Data End : 2009/09/30 DOT Data Number: 00 Version : 2014/04/17 Low Flow Threshold for POC 1 : 50 Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Flat .263 Pervious Total 0.263 Impervious Land Use Acres Impervious Total 0 Basin Total 0.263 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use Acres Pervious Total 0 Impervious Land Use Acres ROADS MOD 0.18 ROOF TOPS FLAT 0.083 Impervious Total 0.263 Basin Total 0.263 13 Element Flows To: Surface Interflow StormTech Chamber -North Name Bottom Bottom Depth: Volume : StormTech Chamber -North Length: 84.00 ft. Width: 8.60 ft. 1 ft. at riser head: 0.0190 acre -ft. Infiltration On Infiltration rate: 8 Infiltration safety factor: 0.25 Groundwater EVEN THOUGH THE STORM TECH SYSTEM HAS A DEPTH OF 22", WHICH INCLUDES THE ROCK BELOW AND ON THE SIDES THAT HAS A40% VOID SPACE. THIS 1 -FT IS THE EQUIVALENT DEPTH Total Volume Infiltrated (ac -ft) : 31.421 ASSUMING 100% VOID SPACE. Total Volume Through Riser (ac -ft): 0 Total Volume Through Facility (ac -ft): 31.421 Percent Infiltrated: 100 Side slope 1: 1 To 1 Side slope 2: 1 To 1 Side slope 3: 1 To 1 Side slope 4: 1 To 1 Discharge Structure Riser Height: 1 ft. Riser Diameter: 12 in. Element Flows To: Outlet 1 Outlet 2 14 Pond Hydraulic Table Stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) Infilt(cfs) 0.0000 0.016 0.000 0.000 0.000 0.0111 0.016 0.000 0.000 0.033 0.0222 0.016 0.000 0.000 0.033 0.0333 0.016 0.000 0.000 0.033 0.0444 0.016 0.000 0.000 0.033 0.0556 0.016 0.000 0.000 0.033 0.0667 0.016 0.001 0.000 0.033 0.0778 0.016 0.001 0.000 0.033 0.0889 0.017 0.001 0.000 0.033 0.1000 0.017 0.001 0.000 0.033 0.1111 0.017 0.001 0.000 0.033 0.1222 0.017 0.002 0.000 0.033 0.1333 0.017 0.002 0.000 0.033 0.1444 0.017 0.002 0.000 0.033 0.1556 0.017 0.002 0.000 0.033 0.1667 0.017 0.002 0.000 0.033 0.1778 0.017 0.003 0.000 0.033 0.1889 0.017 0.003 0.000 0.033 0.2000 0.017 0.003 0.000 0.033 14 0.2111 0.017 0.003 0.000 0.033 0.2222 0.017 0.003 0.000 0.033 0.2333 0.017 0.004 0.000 0.033 0.2444 0.017 0.004 0.000 0.033 0.2556 0.017 0.004 0.000 0.033 0.2667 0.017 0.004 0.000 0.033 0.2778 0.017 0.004 0.000 0.033 0.2889 0.017 0.005 0.000 0.033 0.3000 0.017 0.005 0.000 0.033 0.3111 0.017 0.005 0.000 0.033 0.3222 0.018 0.005 0.000 0.033 0.3333 0.018 0.005 0.000 0.033 0.3444 0.018 0.006 0.000 0.033 0.3556 0.018 0.006 0.000 0.033 0.3667 0.018 0.006 0.000 0.033 0.3778 0.018 0.006 0.000 0.033 0.3889 0.018 0.006 0.000 0.033 0.4000 0.018 0.007 0.000 0.033 0.4111 0.018 0.007 0.000 0.033 0.4222 0.018 0.007 0.000 0.033 0.4333 0.018 0.007 0.000 0.033 0.4444 0.018 0.007 0.000 0.033 0.4556 0.018 0.008 0.000 0.033 0.4667 0.018 0.008 0.000 0.033 0.4778 0.018 0.008 0.000 0.033 0.4889 0.018 0.008 0.000 0.033 0.5000 0.018 0.008 0.000 0.033 0.5111 0.018 0.009 0.000 0.033 0.5222 0.018 0.009 0.000 0.033 0.5333 0.018 0.009 0.000 0.033 0.5444 0.018 0.009 0.000 0.033 0.5556 0.019 0.009 0.000 0.033 0.5667 0.019 0.010 0.000 0.033 0.5778 0.019 0.010 0.000 0.033 0.5889 0.019 0.010 0.000 0.033 0.6000 0.019 0.010 0.000 0.033 0.6111 0.019 0.010 0.000 0.033 0.6222 0.019 0.011 0.000 0.033 0.6333 0.019 0.011 0.000 0.033 0.6444 0.019 0.011 0.000 0.033 0.6556 0.019 0.011 0.000 0.033 0.6667 0.019 0.012 0.000 0.033 0.6778 0.019 0.012 0.000 0.033 0.6889 0.019 0.012 0.000 0.033 0.7000 0.019 0.012 0.000 0.033 0.7111 0.019 0.012 0.000 0.033 0.7222 0.019 0.013 0.000 0.033 0.7333 0.019 0.013 0.000 0.033 0.7444 0.019 0.013 0.000 0.033 0.7556 0.019 0.013 0.000 0.033 0.7667 0.019 0.014 0.000 0.033 0.7778 0.019 0.014 0.000 0.033 0.7889 0.020 0.014 0.000 0.033 0.8000 0.020 0.014 0.000 0.033 0.8111 0.020 0.014 0.000 0.033 0.8222 0.020 0.015 0.000 0.033 0.8333 0.020 0.015 0.000 0.033 15 0.8444 0.020 0.015 0.000 0.033 0.8556 0.020 0.015 0.000 0.033 0.8667 0.020 0.016 0.000 0.033 0.8778 0.020 0.016 0.000 0.033 0.8889 0.020 0.016 0.000 0.033 0.9000 0.020 0.016 0.000 0.033 0.9111 0.020 0.016 0.000 0.033 0.9222 0.020 0.017 0.000 0.033 0.9333 0.020 0.017 0.000 0.033 0.9444 0.020 0.017 0.000 0.033 0.9556 0.020 0.017 0.000 0.033 0.9667 0.020 0.018 0.000 0.033 0.9778 0.020 0.018 0.000 0.033 0.9889 0.020 0.018 0.000 0.033 1.0000 0.020 0.018 0.000 0.033 1.0111 0.021 0.019 0.011 0.033 16 } /ii'OV, NO 611-1 •, , Unl 17 AREA TO BE ROUTED TO STORM TECH SC -740 INFILTRARON SYSTEM PGIS.• (DRI SING SURFACE) 1,470 1,650 (0.085 Ac) NPGIS.• (ROOFTOPS LOTS 3 & 4) 5,500 SF (0.126 Ac) i LOT 1 � X�— LOT 2 1000 s� HLT I LOT PREPARED E DONNA L BRESKE PE, LLC IMPERVIOUS EXHIBIT "B" FOR JAY YOUNG 4 -LOT SP 6621 FOSTER SLOUGH RD. SNOHOMISH, WA 98290 SITE ADDRES: 9332 232ND ST. SW, EDMONDS, WA PHONE: (425) 334-9980 DonnaBreske®comcast.net SCALE: 1 " = 60' DATE: 06-11-2014 FIGURE: 1 of 2 Downstream Connections r Precipitation Applied to Facility r Evaporation Applied to Facili(y Facifity Dimensions Facility Bottom Elevation (ft) Bottom Length (ft) Bottom Width (fit) Effective D epth (ft) Left Side Slope (H.Ai) Bottom Side Slope (HN) Right Side Slope (H/Y) Top Side Slope (HN) Infiltration Measured Infiltration Rate (In/hr) Reduction Factor(Infilt"factor) Isco etted Surface Afea (side -/,jails) Tota[Volume Infiltrated (ac -ft) Total Volume Through Filer (ac -ft) Total Volume Through Facility (ac -ft) Percent Infiltrated Size Inflitir-.tion Pond Target %: 100 25.466 0 25.47 100 Auto Pond,-,__,_ Quick Pond facilit I y Dimension Magram Outlet Structure Data-] Riser Height (ft) Riser Diameter (in) [12: Fiver Type Flat Notch Type Ofifice Diameter Height Number (In) (ft) JC1- 2 10 FY� 3 [6—a Fo -- -7- 1 Pond Volume at Riser Head (ac. -ft) .059 Show Pond Table 1Open Table Initial Stage (ft) I M �1191 I �10 M. 19 Designed to meet the most stringent industry performance standards for superior structural integrity while providing designers with a cost-effective method to save valuable land and protect water resources. The StormTech system is designed primarily to be used under parking lots thus maximizing land usage for commercial municipal applications StormTech SC -740 Chamber (not to scale) Nominal Chamber Specifications Size (L x W x H) 85.4" x 51.0" x 30.0" (2170 x 1295 x 762 mm) Chamber Storage —_j 45.9 W (1.30 m3) (los mm) Minimum Installed Storage* 74.9 ft3 (2.12 m3) Weight 74.0 lbs (33.6 kg) Shipping 30 chambers/pallet 60 end caps/pallet 12 pallets/truck SC -740 End Cap 30.0" (762 mZ/�__ (1295 mm) Typical Cross THE INSTALLED CHAMBER SYSTEM SHALL PROVIDE THE LOAD FACTORS SPECIFIED IN THE AASHTO LRFD Section Detail BRIDGE DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND LIVE LOADS, WITH CONSIDERATION FOR (not to scale) IMPACT AND MULTIPLE VEHICLE PRESENCES. 314-2' (19-50 mm) CLEAN, CRUSHED, ANGULAR STONE— SC-740 CHAMBER ADS 601 GEOTEXTILE OR EQUAL, 90.7" (2300 mm) SC -740 Chamber 85.4" (2170 mm) INSTALLED CHAMBERS SHALL MEET ASTM F 2418-05 `STANDARD SPECIFICATION FOR POLYPROPYLENE (PP) CORRUGATED WALL STORMWATER COLLECTION CHAMBERS." GRANULAR WELL GRADED SOIUAGGREGATE MIXTURES, <35% FINES. COMPACT IN 6'(150 mm) LIFTS TO 95% STANDARD PROCTOR DENSITY. SEE THE TABLE OF ACCEPTABLE FILL MATERIALS. RUTTING FROM VEHICLES MAY OCCUR, INCREASE COVER TO 24° (610 MNI) SC -740 END CAP T 96" 18" (460 mm) (2440 mm) M N. MAX. s 6' (150 mm) MIN. J 1� �- 30'(762 mm) SC -740 �c 4 DEPTH OF STONE O BE DETERMINED BY DESIGN ENGINEER' 6" (150 mm) MIN. DESIGN ENGINEER IS RESPONSIBLE FOR J 51" (1295 mm) MIN. �_ ENSURING THE REQUIRED BEARING CAPACITY 6° (750 mm) MIN. - 12" MIN. (305 mm) TYP. OF SUBGRADE SOILS' THIS CROSS SECTION DETAILS THE REQUIREMENTS NECESSARY TO SATISFY THE LOAD FACTORS SPECIFIED IN THE AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND LIVE LOADS USING STORMTECH CHAMBERS 20 SC -740 Cumulative Storage Volumes Per Chamber Assumes 40% Stone Porosity. Calculations are Based Upon a 6'(152 mm) Stone Base Under the Chambers. r,t 1 8 17 41 1041 - 45.90 1.300} 45.90 1.300 M__ 73.77 2.089 40 1016 Stone 45.901.300 _72.64 2.057 39(.991.) Cover 45.90 1.300 71.52 2.025 38 C9165 12_(305)___] 1.300 70.39 1.993 37 948 _ 36 L914) 35 889) `_45.90 1 45.90(L3001_69.26 45.901.300)_ 45.85 1.298 1.961 ___ 68.14 (1.9_29) 66.98 1.897_ 34 864 _ _ 45.69 1.294Y_ ___65.75_0.862 _ 33 838 1.286 64.46 1.825 32813 ____45.41 44.81 1.269 62.97 X1.783 31 787 44.01 1.246 61.361.737 30A762 _ 43.061.219 59.66 1.689 29 (737) 41.98 1.189 57.89 (1.639 28711 _ ____ 40.80 1.155 56.05 1.587 27 (686) _ 39.54 1.120 54.17J1_534 _ 26 660 38.18 (1.081) 52.23 1.479 2635)_ 24 610 - -223 ___) -_36.74 X40 35.22 0.977 _ - 50.23 (1.422)- 48.19 .365 (1 584 33.64 0.953 46.11 (UU6 22559) _ 21 (533) 31.99 (0 . 9 06L 30.29 0.858 00 1.246) -� 41.85 1.185 201508 __ -28.54 0.808L 39.67 1.123 19(483) 26.74(0_757 37.47 1,061) _ 18457 24.89 0.705 35.23 0.997 17 432 23.00 0.651 32.96 0.939 ___16406 _ 21.06 (0.596 30.68 (O 69) 15 (3$1) 19.09 0.541 28.36 0.803 14 356 - 17.08(0.484)__ 26.03 (0.737)_ 13 330) 15.04 (0_426 23.68 0.670 12 (305) 12.97 0.367 __21.31 0.608 _ 11 279 10.87 0.309 18.92 0.535 254 10 (M41_ 8.74 0.247 16.51 0.468 9(229} __E2 6.58 (0.188 4.41 (0.125) 14.09( Q.3991_ 11.66 (0.330) 7-_(11j8_ - 6_(152) 2.21 0.063 -- 0_ 9.21 0264 6.76 0.191 - 51127) 4 102 0 Stone Foundation 0 __J.63 (0.160) (0.125} _ 3 76 2 51 - -_ 0 0 3.38_(0.095) 2.25 0.064 - - ---1 (25) -- - 0 1.13 (0.032) Note: Add 1.13 cu. ft. (0.032 m 3) of storage for each additional inch (25 mm) of stone foundation. A 1 •` � i 1 • • Storage Volume Per Chamber Note: Storage volumes are in cubic feet per chamber. Assumes 40% porosity for the stone plus the chamber volume. Amount of Stone Per Chamber ENGLISH TONS (CUBIC YARDS) Bare Chamber and Stone 12" Chamber Stone Foundation Depth 3.8 (2.8 yd3) Storage in. (mm) 6 (150) 12_(305)___] 18 (460) l 450 mm (m3) StormTech SC -740 __it, 45.9(l.3) 74.9 (2.1) 81.7 (2.3) 88.4 (2.5) Note: Storage volumes are in cubic feet per chamber. Assumes 40% porosity for the stone plus the chamber volume. Amount of Stone Per Chamber ENGLISH TONS (CUBIC YARDS) Stone Foundation Depth 6" 12" 18" StormTech SC -740 3.8 (2.8 yd3) 4.6 (3.3 yd3) 5.5 (3.9 yd3) METRIC KILOGRAMS (METERS) 150 mm 305 mm 450 mm StormTech SC -740 3450 (2.1 m3) _ 4170 (2.5 m3) 4490 (3.0 m3) J Note: Assumes 6'(150 mm) of stone above, and between chambers. Volume of Excavation Per Chamber _Stone Foundation Depth 5 6' (150 mm) �12' (30mm) 18" (460 mm) StormTech SC -740 5.5 (4.2) 6.2 (4,7) 6.8 (5.2) Note: Volumes are in cubic yards (cubic meters) per chamber. Assumes 6'(150 mm) of separation between chamber rows and 18" (460 mm) of cover. The volume of excavation will vary as the depth of the cover increases. STANDARD LIMITED WARRANTY OF STORMTECH LLC ("STORMTECH"): PRODUCTS (A) This Limited Warranty applies solely to the StormTech chambers and endplates manufactured by StormTech and sold to the original purchaser (the "Purchaser"). The chambers and endplates are collectively referred to as the "Products." (B) The structural integrity of the Products, when installed strictly in accordance with StormTech's written installation instructions at the time of installation, are warranted to the Purchaser against defective materials and workmanship for one (1) year from the date of purchase. Should a de- fect appear in the Limited Warranty period, the Purchaser shall provide StormTech with written notice of the alleged defect at StormTech's corporate headquarters within ten (10) days of the discovery of the defect. The notice shall describe the alleged defect in reasonable detail. StormTech agrees to supply replacements for those Products determined by StormTech to be defective and covered by this Limited Warranty. The supply of replacement products is the sole remedy of the Purchaser for breaches of this Limited Warranty. StormTech's liability specifically excludes the cost of removal and/or installation of the Products. (C) THIS LIMITED WARRANTY IS EXCLUSIVE. THERE ARE NO OTHER WARRANTIES WITH RESPECT TO THE PRODUCTS, INCLUDING NO IMPLIED WARRANTIES OF MERCHANT -ABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE. (D) This Limited Warranty only applies to the Products when the Products are installed in a single layer. UNDER NO CIRCUMSTANCES, SHALL THE PRODUCTS BE INSTALLED IN A MULTI -LAYER CONFIGURATION. (E) No representative of StormTech has the authority to change this Limited Warranty in any manner or to extend this Limited Warranty. This Limited Warranty does not apply to any person other than to the Purchaser. (F) Under no circumstances shall StormTech be liable to the Purchaser or to any third party for prod- uct liability claims; claims arising from the design, shipment, or installation of the Products, or the cost of other goods or services related to the purchase and installation of the Products. For this Limited Warranty to apply, the Products must be installed in accordance with all site condi- tions required by state and local codes; all other applicable laws; and StormTech's written in- stallation instructions. (G) THE LIMITED WARRANTY DOES NOT EXTEND TO INCIDENTAL, CONSEQUENTIAL, SPE- CIAL OR INDIRECT DAMAGES. STORMTECH SHALL NOT BE LIABLE FOR PENALTIES OR LIQUIDATED DAMAGES, INCLUDING LOSS OF PRODUCTION AND PROFITS; LABOR AND MATERIALS; OVERHEAD COSTS; OR OTHER LOSS OR EXPENSE INCURRED BY THE PURCHASER OR ANY THIRD PARTY. SPECIFICALLY EXCLUDED FROM LIMITED WAR- RANTY COVERAGE ARE DAMAGE TO THE PRODUCTS ARISING FROM ORDINARY WEAR AND TEAR; ALTERATION, ACCIDENT, MISUSE, ABUSE OR NEGLECT; THE PRODUCTS BEING SUBJECTED TO VEHICLE TRAFFIC OR OTHER CONDITIONS WHICH ARE NOT PERMITTED BY STORMTECH'S WRITTEN SPECIFICATIONS OR INSTALLATION INSTRUC- TIONS; FAILURE TO MAINTAIN THE MINIMUM GROUND COVERS SET FORTH IN THE INSTALLATION INSTRUCTIONS; THE PLACEMENT OF IMPROPER MATERIALS INTO THE PRODUCTS; FAILURE OF THE PRODUCTS DUE TO IMPROPER SITING OR IMPROPER SIZING; OR ANY OTHER EVENT NOT CAUSED BY STORMTECH. THIS LIMITED WAR- RANTY REPRESENTS STORMTECH'S SOLE LIABILITY TO THE PURCHASER FOR CLAIMS RELATED TO THE PRODUCTS, WHETHER THE CLAIM IS BASED UPON CON- TRACT, TORT, OR OTHER LEGAL THEORY. Wethersfield ( Connecticut 06109 3.84011 fax 860-529-8040 www.stormtech.com 21 TECH CC -740 CHAMBER. Printed on recycled paper 1�j Si6 090508 WWHM2012 PROJECT REPORT Project Name: Infiltration Storm Tech Chamber SC -740 Site Name: Jay Young Site Address: 9332 232nd ST SW City : Edmonds, WA Report Date: 6/12/2014 MGS Regoin Puget East Data Start 1948/10/01 Data End : 2009/09/30 DOT Data Number: 00 Version : 2014/04/17 Low Flow Threshold for POC 1 : 50 Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name : Bio Retention Cell for PGIS from Lots 3 & 4 Bypass: No GroundWater: No Pervious Land Use Acres C, Forest, Mod .211 Pervious Total 0.211 Impervious Land Use Acres Impervious Total 0 Basin Total 0.211 Element Flows To: Surface Interflow MITIGATED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use Acres Pervious Total 0 Impervious Land Use Acres ROADS MOD 0.126 DRIVEWAYS MOD 0.085 Impervious Total 0.211 Groundwater Basin Total 0.211 22 Element Flows To: Surface Interflow Groundwater Storm Tech Chamber SC -740 Name : Storm Tech Chamber SC 740- SOUTH Bottom Length: 100.00 ft. Bottom Width: 10.50 ft. Depth: 2 ft. Volume at riser head: 0.0586 acre -ft. Infiltration On Infiltration rate: 0.24 Infiltration safety factor: 1 Total Volume Infiltrated (ac -ft): 25.466 Total Volume Through Riser (ac -ft): 0 Total Volume Through Facility (ac -ft): 25.466 Percent Infiltrated. 100 EVEN THOUGH THE STORM TECH SC -740 Side slope 1: 1 To 1 Stage(ft) Side slope 2: 1 To 1 SYSTEM HAS A TOTAL DEPTH OF 42", THIS Side slope 3: 1 To 1 IS THE EQUIVALENT DEPTH ASSUMING Side slope 4: 1 To 1 100% VOID SPACE AND THUS TAKING INTO Discharge Structure CONSIDERATION THE 40% VOID SPACE OF Riser Height: 2 ft. 0.0444 Riser Diameter: 12 in. ROCK ABOVE, BELOW, AND ON THE SIDE 0.005 0.0667 OF THE STORM TECH CHAMBERS, Element Flows To: Outlet 1 Outlet 2 23 Pond Hydraulic Table Stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) Infilt(cfs) 0.0000 0.024 0.000 0.000 0.000 0.0222 0.024 0.000 0.000 0.005 0.0444 0.024 0.001 0.000 0.005 0.0667 0.024 0.001 0.000 0.005 0.0889 0.024 0.002 0.000 0.005 0.1111 0.024 0.002 0.000 0.005 0.1333 0.024 0.003 0.000 0.005 0.1556 0.024 0.003 0.000 0.005 0.1778 0.025 0.004 0.000 0.005 0.2000 0.025 0.004 0.000 0.005 0.2222 0.025 0.005 0.000 0.005 0.2444 0.025 0.006 0.000 0.005 0.2667 0.025 0.006 0.000 0.005 0.2889 0.025 0.007 0.000 0.005 0.3111 0.025 0.007 0.000 0.005 0.3333 0.025 0.008 0.000 0.005 0.3556 0.025 0.008 0.000 0.005 0.3778 0.026 0.009 0.000 0.005 23 0.4000 0.026 0.010 0.000 0.005 0.4222 0.026 0.010 0.000 0.005 0.4444 0.026 0.011 0.000 0.005 0.4667 0.026 0.011 0.000 0.005 0.4889 0.026 0.012 0.000 0.005 0.5111 0.026 0.013 0.000 0.005 0.5333 0.026 0.013 0.000 0.005 0.5556 0.027 0.014 0.000 0.005 0.5778 0.027 0.014 0.000 0.005 0.6000 0.027 0.015 0.000 0.005 0.6222 0.027 0.016 0.000 0.005 0.6444 0.027 0.016 0.000 0.005 0.6667 0.027 0.017 0.000 0.005 0.6889 0.027 0.017 0.000 0.005 0.7111 0.027 0.018 0.000 0.005 0.7333 0.027 0.019 0.000 0.005 0.7556 0.028 0.019 0.000 0.005 0.7778 0.028 0.020 0.000 0.005 0.8000 0.028 0.020 0.000 0.005 0.8222 0.028 0.021 0.000 0.005 0.8444 0.028 0.022 0.000 0.005 0.8667 0.028 0.022 0.000 0.005 0.8889 0.028 0.023 0.000 0.005 0.9111 0.028 0.024 0.000 0.005 0.9333 0.028 0.024 0.000 0.005 0.9556 0.029 0.025 0.000 0.005 0.9778 0.029 0.026 0.000 0.005 1.0000 0.029 0.026 0.000 0.005 1.0222 0.029 0.027 0.000 0.005 1.0444 0.029 0.028 0.000 0.005 1.0667 0.029 0.028 0.000 0.005 1.0889 0.029 0.029 0.000 0.005 1.1111 0.029 0.030 0.000 0.005 1.1333 0.030 0.030 0.000 0.005 1.1556 0.030 0.031 0.000 0.005 1.1778 0.030 0.032 0.000 0.005 1.2000 0.030 0.032 0.000 0.005 1.2222 0.030 0.033 0.000 0.005 1.2444 0.030 0.034 0.000 0.005 1.2667 0.030 0.034 0.000 0.005 1.2889 0.030 0.035 0.000 0.005 1.3111 0.030 0.036 0.000 0.005 1.3333 0.031 0.036 0.000 0.005 1.3556 0.031 0.037 0.000 0.005 1.3778 0.031 0.038 0.000 0.005 1.4000 0.031 0.038 0.000 0.005 1.4222 0.031 0.039 0.000 0.005 1.4444 0.031 0.040 0.000 0.005 1.4667 0.031 0.040 0.000 0.005 1.4889 0.031 0.041 0.000 0.005 1.5111 0.032 0.042 0.000 0.005 1.5333 0.032 0.043 0.000 0.005 1.5556 0.032 0.043 0.000 0.005 1.5778 0.032 0.044 0.000 0.005 1.6000 0.032 0.045 0.000 0.005 1.6222 0.032 0.045 0.000 0.005 1.6444 0.032 0.046 0.000 0.005 24 1.6667 0.032 0.047 0.000 0.005 1.6889 0.032 0.048 0.000 0.005 1.7111 0.033 0.048 0.000 0.005 1.7333 0.033 0.049 0.000 0.005 1.7556 0.033 0.050 0.000 0.005 1.7778 0.033 0.051 0.000 0.005 1.8000 0.033 0.051 0.000 0.005 1.8222 0.033 0.052 0.000 0.005 1.8444 0.033 0.053 0.000 0.005 1.8667 0.033 0.054 0.000 0.005 1.8889 0.034 0.054 0.000 0.005 1.9111 0.034 0.055 0.000 0.005 1.9333 0.034 0.056 0.000 0.005 1.9556 0.034 0.057 0.000 0.005 1.9778 0.034 0.057 0.000 0.005 2.0000 0.034 0.058 0.000 0.005 2.0222 0.034 0.059 0.032 0.005 25 FAVOR ; I� .%: k «: 26 June 1, 2014 4 -Lot Plat L&A Job No. 14-036 Page 16 Cleanouts Sufficient number of cleanouts at strategic locations should be provided for underground drain lines. The underground drain lines should be cleaned and maintained periodically to prevent clogging. ONSITE STORMWATER DISPOSAL General The glacial till soil layer underlying the site is of extremely low permeability, while the recessional outwash overlying and the advance outwash underlying the till layer are of higher permeability. Soil particle size distribution tests were conducted on three soil samples obtained from the outwash deposits to determine infiltration rates of. Based on these test results, stormwater collected over impervious surfaces of the development may be disposed onsite by infiltration into the outwash deposits. Particle Size Distribution Tests and Estimated Infiltration Rates Three soil samples, one from each of Test Pits 2, 3 and 4, were obtained from either recessional outwash overlying the till deposit or advance outwash Underlying the till deposit under the project site and taken to HWA laboratory for Particle Size Distribution tests to determine their infiltration rates. These soil samples are listed in the table below and their test reports are presented on Plates A-1 and A-2. 27 June 1, 2014 4 -Lot Plat L&A Job No. 14-036 Page 17 LIST OF SOIL SAMPLES Sample Test Pit Depth Soil No. No. feet Description 2 1 6.5-7.5 Olive brown, poorly graded sand with gravel 3 2 3.0-4.0 Brown, poorly graded gravel with silt and sand 4 5 9.0-10.0 Olive brown, silty fine sand with gravel The percentages of clay, silt and sand/gravel of the soil samples determined from the particle size distribution tests are summarized on Plate A-2. Based on these percentages the soil samples were classified according to the USDA (U.S. Department of Agriculture) Texture Triangle chart, a copy of which is shown on Plate A-3 in the attached Appendix. The classifications of soil samples are presented in the table below. USDA TEXTURE TRIANGLE_ CLASSIFICATION OF SOIL SAMPLES Sample Percentage Percentage Percentage USDA Texture No. Clay Silt Sand/Gravel Triangle Classification 1 0.5 2.5 97.0 Sand 2 1.7 4.9 93.4 Sand 3 2.7 11.9 85.4 Sand The Stormwater Management Manual for Western Washington, 2005 Edition, published by Washington State Department of Ecology, is used to determine estimated design infiltration rates of the target soil layers from which soil samples were obtained. According to the table of Recommended Infiltration Rates Based on USDA Soil Textural Classification shown on Plate A-4, the estimated short-term and long-term infiltration rates would be 8 iph (inches per hour) and 2.0 iph, respectively, for "sand". The long- 28 June 1, 2014 4 -Lot Plat L&A Job No. 14-036 Page 18 term rate is derived from the short-term rate with a correction factor of 4. The infiltration rates thus determined for the soil samples are presented on the table below. The Djo sizes of the soil samples determined from their particle size distribution tests are shown on Plate A-2. The Dip size is the size of soil particles of 10% passing by weight. According to the table of Alternative Recommended Infiltration Rates Based On ASTM Gradation Testing presented on Plate A-5, the Alternative Estimated Infiltration Rates of the soil samples can be determined by interpolation according to their D10 sizes, The recommended infiltration rates of the soil samples thus determined are listed in the table below. b ESTIMATED INFILTRATION RATES Sample ESTIMATED INFILTRATION RATES D10 Estimated Lon -Term Sample Test Pit Estimated Infiltration Rate, Inch./Hour No. No. Short Term Correction Factor Long Term 1 2 8.0 4 2.0 2 3 8.0 4 10 3 4 8.0 4 2.0 'Based on USDA Texture Triangle Classification The Djo sizes of the soil samples determined from their particle size distribution tests are shown on Plate A-2. The Dip size is the size of soil particles of 10% passing by weight. According to the table of Alternative Recommended Infiltration Rates Based On ASTM Gradation Testing presented on Plate A-5, the Alternative Estimated Infiltration Rates of the soil samples can be determined by interpolation according to their D10 sizes, The recommended infiltration rates of the soil samples thus determined are listed in the table below. b ESTIMATED INFILTRATION RATES Sample Test D10 Estimated Lon -Term No. Pit No. size Infiltration Rate, Inch/Hour 1 2 0.1666 3.00 2 3 0.1695 3.04 3 4 0.0147 0.24 b Based on D10 size of soil samples 29 June 1, 2014 4 -Lot Plat L&A Job No. 14-036 Page 19 Recommended Design Infiltration hates for Infiltration Trenches The design infiltration rates shown on the above table should be used for design of infiltration trenches to be installed near the test pits from which the soil samples were obtained. The bottom of infiltration ponds or infiltration trenches should be excavated at least 6 inches into the target soil layers from which the soil samples were obtained. Infiltration Trench Constriction The soil unit at bottom of infiltration trenches should be verified by a geotechnical engineer. The stability of the trench cut bank should also be verified by a geotechnical engineer during excavation. The infiltration trenches should be set back at least 5 feet from property lines and 10 feet from nearby building footing foundations or utility trenches. Also, the bottom of infiltration trenches should be lower than the adjacent footing foundations and utility trenches. The infiltration trenches should be at least 24 inches wide. IThe side walls of the trenches should be lined with a layer of non -woven filter fabric, such as MIRAFI 140N5. The trenches are then filled with clean, 3/4 to 1-1/2 inch, washed gravel or crushed rock to within about 10 inches of the finish grade. The dispersion pipes should be constructed of 4 -inch rigid PVC pipes and laid level in the gravel or crushed rock filled trenches at about 16 inches below the top of trenches. The top of the gravel or crushed rock fill should also be covered with the filter fabric liner. The remaining trenches should then be backfilled with compacted onsite clean soils. The gravel or crushed rock fill should be placed in lifts no more than 10 inches thick in loose state, with each lift compacted to a non - yielding state with a vibratory mechanical compactor. The compaction and densification 30 June 1, 2014 4 -Lot Plat L&A Job No. 14-036 Page 20 of trench fill is critical if it is to support driveways. Stormwater captured over paved driveways should be routed into a catch basin equipped with an oil -water separator before being released into the infiltration trenches. The subject site is underlain at shallow depth by very -dense glacial till and dense advance outwash sand deposits. These deposits are of very -high to high shear strength and the site should be quite stable. it is our opinion that if the recommendations in this report are fully implemented and observed during construction and following the completion of construction, the areas disturbed by construction will remain stable and will not increase the potential for soil movement. In our opinion, the risk for damages to the proposed development and from the development to adjacent properties from soil instability should be minimal. This report has been prepared for the specific application to this project for the exclusive use by Real Property Associates, Inc., and its associates, representatives, consultants and contractors. We recommend that this report, in its entirety, be included in the project contract documents for the information of prospective contractors for their estimating and bidding purposes and for compliance with the recommendations in this report during construction. The conclusions and interpretations in this report, however, should not be construed as a warranty of the subsurface conditions. The scope of this study does not include services related to construction safety precautions and our recommendations are not intended to direct the contractor's methods, techniques, sequences or procedures, LIJ & ASSOCIATES9 INC. 31 ----- - m N 68'25'36' W ______..._._ __-a•'^,. `=-_ _=—- -- 332.68' A s2 2ndi,SFREET S.W. o _WATCH` . cv:. _ 3' FENCE \ fEIICE 0 O C 1 ' y\ 270335bal700 Z7b3`600i V 0 !Jl i �`E4.N HAI:NING Z'CHMO F< aQYVA KEPIS 9330 232N0 STR£T SM 9322 232ND SiREEi S.W. CR.'ONR$ WA. 90:,20 EGwNJ05 WA. 95020 ro 0214, 9 YO \ z� ! k1i r CY A, 11Nt i Clz+,i: 21031,FrEi � .YL 3314 21 ( 931+ 232nf EC+.IONDS, W-1AN 88'25'36_W 1 ___ 740.70' s' awN une Face _, \ C / 6' 1W W FENCE + 5 4.3 ihi i y ss 3 a 1 aR��,VE, Q ) - � � 3• wow�EENCE _r O !' 7.0' z I `n •' - 39.3' q5/ 2 a C `JOIAK i>iVSi 3-1 +wmc�r `—'— h'O3. V11119902,11s a ��/" T1P. WALA.5 —' Jw / \ Z EX 0.75' NF6E � p o f J r .8 _ _ { — ._�, tY.o• 19a7 ca+c =' _ _ _ -�++ + s i i I BLOCK WALL (TrPJ� C �-TYr. WALL I I o s cor Z J rn i ! �J �.3 Y / S 4Cr1�RE• x NCA Rol51p`ET SW as mr f 1 n WA n>o T / WALL- / EX. 7-1/4' EX. 7-3/4' .75' wuq CONC - -- -- — — '-J IRON PIPE IRON PIPE M WN1 N-0.3' E-0.3' N-0,2' E-0.1' "` ' I a \ Y•. N 88"25'36" W SITE AND EXPLORATION LOCATION PLAN LTU ASSOCIATES, INC. 4 -LOT PLAT 9333 - 232ND STREET SW Geotechnical Engineering •Engineering Geology •Earth Science EDMONDS, WASHINGTON _._ JOB NO, 14-036 DATE 4/18/2014 PLATE 32 Logged By: JSL Date: 4/23/2014 Sampl )epth uscs Soil Description No. ft, CLASS. OL Dark -brown, loose, organic, silty fine SANFine , 1 ---- --moist ¢QP�DIL)------------------ SM Brown to light -brown, medium -dense, silty some gravel, 2 moist W 4 5 ------- ----- ---- ---- SM _ Light -gray, very -dense, gravelly, silty, fine SAND, occasional 64 cobble, slightly moist (VASHON TILL) 7891 8 9 Test pit terminated at 8.0 ft; groundwater not encountered. 10 TEST PIT NO. 2 Logged By: JSL Date: 4/23/2014 Y Ground El. ( w Other Test )epth uscs Soil Description No. ry, GLASS. OL Dark -brown to black, loose, organic, silty fine SAND, with fine roots_ 1 ____ ---moist{-K3P�BI�)---------------------- SM Brown to light -brown, medium -dense, silty fine SAND, some gravel, 2 slightly moist 3 SM Light -gray, very -dense, gravelly, silty, fine SAND, occasional cobble, 5 4 cemented, slightly moist (VASHON TILL) e — gp Light -gray, dense, fine to medium SAND, some gravel, slightly moist (ADVANCE OUTWASH`�') 7 8 9 10 I ITest pit terminated at 9.0 ft: groundwater not encountered. UU & ASSOCIATES, INC. Geotechnical Engineenng - Engineering Geology * Earth Science Ground EI. Ot/FherTest TEST PIT LOGS 4 -LOT PLAT 9333 - 232ND STREET SW EDMONDS, WASHINGTON JOB NO. 14-036_ DATE 4/24 /2Q14 PLATE 4 33 34 x� i 35 Ai IMPERVIOUS AREAS D DISTURBED AREAS BMP T5.13 POST CONSTRUCTION SOIL QUALITY AND DEPTH: ALL DISTURBED AREAS, (NOT OTHERWISE COVERED BY IMPERVIOUS AREA), ON AND OFF SITE, SHALL MEET THE COMPOST AMENDED REQUIREMENTS OF BMP T5.13 IN THE 2005 DOE STORMWATER MANUAL VOLUME V, CHAPTER 5. CALCULATED AMENDMENT RATES MAY BE MET THROUGH USE OF TOPSOIL AND DUFF FROM THE PROPERTY AMENDED TO MEET THE CARBON TO NITROGEN RATIO REQUIREMENTS, AND MEETING THE CONTAMINANT STANDARDS OF GRADE A COMPOST TOPSOIL DEPTHS SHALL HAVE A MINIMUM DEPTH OF EIGHT INCHES EXCEPT WHERE TREE ROOTS LIMIT THE DEPTH OF INCORPORATION OF AMMENDMENTS NEEDED TO MEET THE CRI TERIA. SUBSOIL BELOW THE TOPSOIL LAYER SHOULD BE SCARIFIED AT LEAST 4 INCHES WITH SOME INCORPORATION OF THE UPPER MATERIAL TO AVOID STRATIFIED LAYERS WHERE FEASIBLE. PTD NON -DISTURBED AREAS so' o so' SCALE: 1" = 60' PREPARED BY: SOIL MANAGEMENT EXHIBIT FOR JAY YOUNG 4 -LOT SP DONNA L BRESKE PE, LLC 6621 FOSTER SLOUGH RD. SITE ADORES: 9332 232ND ST. SW, EDMONDS, WA SNOHOMISH, WA 98290 PHONE. (425) 334-9980 DonnaBreske®comcast.net SCALE: 1" = 60' DATE: 06-11-2014 FIGURE: 1 of 1 79M No. 5 — Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is " performed General Trash & Trash or debris which is located immediately No Trash or debris located Debris in front of the catch basin opening or is immediately in front of blocking inletting capacity of the basin by catch basin or on grate more than 10%. opening. Trash or debris (in the basin) that exceeds 60 No trash or debris in the percent of the sump depth as measured from catch basin. the bottom of basin to invert of the lowest pipe into or out of the basin, but in no case less than a minimum of six inches clearance from the debris surface to the invert of the lowest pipe. Trash or debris in any inlet or outlet pipe Inlet and outlet pipes free blocking more than 1/3 of its height. of trash or debris. Dead animals or vegetation that could No dead animals or generate odors that could cause complaints vegetation present within or dangerous gases (e.g., methane). the catch basin. Sediment Sediment (in the basin) that exceeds 60 No sediment in the catch percent of the sump depth as measured from basin the bottom of basin to invert of the lowest pipe into or out of the basin, but in no case less than a minimum of 6 inches clearance from the sediment surface to the invert of the lowest pipe. Structure Top slab has holes larger than 2 square Top slab is free of holes Damage to inches or cracks wider than 1/4 inch and cracks. Frame and/or Top Slab (Intent is to make sure no material is running into basin). Frame not sitting flush on top slab, i.e., Frame is sitting flush on separation of more than 3/4 inch of the frame the riser rings or top slab from the top slab. Frame not securely and firmly attached. attached Fractures or Maintenance person judges that structure is Basin replaced or repaired Cracks in unsound. to design standards. Basin Walls/ Bottom Grout fillet has separated or cracked wider Pipe is regrouted and than 1/2 inch and longer than 1 foot at the secure at basin wall. joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. Settlement/ If failure of basin has created a safety, Basin replaced or repaired Misalignment function, or design problem. to design standards. Vegetation Vegetation growing across and blocking more No vegetation blocking than 10% of the basin opening. opening to basin. Vegetation growing in inlet/outlet pipe joints No vegetation or root that is more than six inches tall and less than growth present. six inches apart. Contamination See "Detention Ponds" (No. 1). No pollution present. and Pollution Volume V— Rznioff Treatment BMPs — August 2012 4-37 38 No. 5 — Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Needed Maintenance is General Trash and Trash or debris that is plugging more performed Catch Basin Cover Not in Cover is missing or only partially in place. Catch basin cover is Cover Place Any open catch basin requires maintenance. closed Locking Mechanism cannot be opened by one Mechanism opens with Mechanism maintenance person with proper tools. Bolts proper tools. Bars are missing or entire barrier Not Working into frame have less than 1/2 inch of thread. Cover Difficult One maintenance person cannot remove lid Cover can be removed by Bars are loose and rust is causing 50% to Remove after applying normal lifting pressure. one maintenance person. (Intent is keep cover from sealing off access design standards. Inlet/Outlet to maintenance.) Barrier firmly attached to pipe Ladder Ladder Rungs Ladder is unsafe due to missing rungs, not Ladder meets design Unsafe securely attached to basin wall, standards and allows misalignment, rust, cracks, or sharp edges. maintenance person safe access. Metal Grates Grate opening Grate with opening wider than 7/8 inch. Grate opening meets (If Applicable) Unsafe design standards. Trash and Trash and debris that is blocking more than Grate free of trash and Debris 20% of grate surface inletting capacity. debris. Damaged or Grate missing or broken member(s) of the Grate is in place and Missing. grate. meets design standards. No. 6 — Debris Carriers (e.g., Trash Racks) Maintenance Defect Condition When Maintenance is Results Expected When Components Needed Maintenance is Performed General Trash and Trash or debris that is plugging more Barrier cleared to design flow Debris than 20% of the openings in the barrier. capacity. Metal Damaged/ Bars are bent out of shape more than 3 Bars in place with no bends more Missing inches. than 3/4 inch. Bars. Bars are missing or entire barrier Bars in place according to design. missing. Bars are loose and rust is causing 50% Barrier replaced or repaired to deterioration to any part of barrier. design standards. Inlet/Outlet Debris barrier missing or not attached to Barrier firmly attached to pipe Pipe pipe Volume V— Runoff Treatment BMPs — August 2012 39 4-38 No. 2 — Infiltration Maintenance Defect Conditions When Maintenance Is Results Expected When Component Needed Maintenance Is Performed General Trash & Debris See "Detention Ponds" (No. 1). See "Detention Ponds" (No. 1). Poisonous/Noxious See "Detention Ponds" (No. 1). See "Detention Ponds" Vegetation (No. 1). Contaminants and See "Detention Ponds" (No. 1). See "Detention Ponds" Pollution (No. 1). Rodent Holes See "Detention Ponds" (No. 1). See "Detention Ponds" (No. 1) Storage Area Sediment Water ponding in infiltration pond after Sediment is removed rainfall ceases and appropriate time and/or facility is cleaned allowed for infiltration. so that infiltration system works according to (A percolation test pit or test of facility design. indicates facility is only working at 90% of its designed capabilities. If two inches or more sediment is present, remove). Filter Bags (if Filled with Sediment and debris fill bag more than 1/2 Filter bag is replaced or applicable) Sediment and full. system is redesigned. Debris Rock Filters Sediment and By visual inspection, little or no water flows Gravel in rock filter is Debris through filter during heavy rain storms. replaced. Side Slopes of Erosion See "Detention Ponds" (No. 1). See "Detention Ponds" Pond (No. 1). Emergency Tree Growth See "Detention Ponds" (No. 1). See "Detention Ponds" Overflow Spillway (No. 1). and Berms over 4 feet in height. Piping See "Detention Ponds" (No. 1). See "Detention Ponds" (No. 1). Emergency Rock Missing See "Detention Ponds" (No. 1). See "Detention Ponds" Overflow Spillway (No. 1). Erosion See "Detention Ponds" (No. 1). See "Detention Ponds" (No. 1). Pre -settling Facility or sump 6" or designed sediment trap depth of Sediment is removed. Ponds and Vaults filled with Sediment sediment. and/or debris February 2005 Volume V — Runoff Treatment BMPs 4-33 Eno