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HomeMy WebLinkAboutPermit File BLD-2021-0795 4008 Saint Mary's Drive (4)�1T Y a� r qc0 L Storm Water Drainage Report Minimum Requirements 1 through 9 ENGINEERING DEPARTMENT 904 6t" Street Anacortes, WA 98221 Official use Only: (Information to Inspectors) Required Storm Water Facility and other related requirements: t'1n1� T • ID L- F�c�z Aty�t'lc� www.anacorteswa.aov Project Address: 4008 4010 Saint Mary's Drive Submittal Date: I b• 2a21 Parcel Number: _ 5 874 & P135638 Revision Number: Permit Number: BLD-2021- Reviewer:-t! LAo* c., Acceptance Date (COA)09 • L 2:021 FRONT OF REPORT: Submittal Checklist: (All items listed below are required for a complete submittal) o Cover Sheet (Preparer to Provide): Project title, Location, Revision dates, Engineer's Stamp o TAB 1: Minimum Requirement #1 - Preparation of Stormwater Site Plans o TAB 2: Minimum Requirement #2 - Construction Stormwater Pollution Prevention (SWPP) o TAB 3: Minimum Requirement #3 -Source Control of Pollution o TAB 4: Minimum Requirement #4 -Preservation of Natural Drainage Systems and Outfalls o TAB 5: Minimum Requirement #5 - On -site Stormwater Managements o TAB 6: Minimum Requirement #6 -Runoff Treatment o TAB 7: Minimum Requirement #7 -Flow Control o TAB 8: Minimum Requirement #8 -Wetland Protection o TAB 9: Minimum Requirement #9 - Operation and Maintenance o APPENDIX 1 -Survey performed by a Professional Land Surveyor o APPENDIX 2 - Soils Analysis (Volume 1, Chapter 3.1.1) o APPENDIX 3 - Model Soil Management Plan for BMP T5.13 o APPENDIX 4 -Determining Construction Site Sediment Damage Potential (Appendix 7) o APPENDIX 5 -Site Plan with all applicable information (Minimum Size 11x17 - 30 scale) o APPENDIX 6 -Documented Site Photos (North, South, East and West) o APPENDIX 7 -Drainage BMP Facility Maintenance Covenant, if applicable. To be recorded prior to the Temporary Certificate of Occupancy, Certificate of Occupancy or Final Acceptance, Stormwater Management Requirements: Version Date: October 7, 2019 Previous Version Date: February 20, 2019 o Refer to the 2012\14 Department of Ecology Manual, as amended in 2014 for further required information. o See also, City of Anacortes Municipal Code 19.76 for additional information o See also, current Engineering Development Standards, Chapter 2- Storm Drainage for additional information. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Project Description and Summary: Summary Table Existing Proposed Development Type Undeveloped Lots House/garage Number of Lots 2 2 Lot Acreage in SF 173652 SF 17,652 SF Soil Type(s) Keystone Loamy Sand Site Sediment Transport Score (High\Low) 45 Low Depth to Ground Water Table (Feet and Inches) See completed Soils Analysis Volume 1, Chapter 3.1.1 19"-20" Infiltration Rate during Rainy Season (Inch\Per Hour) N/A Impervious Surface (on -site) 0 61571 SF Impervious Surface (off -site) 0 0 sf New and Replaced Hard Surface Total (SF) 0 6,571 sf Lot Coverage (Percentage) 0 37% BMP (Required Minimum Requirement 5) BMP T5.13 Post Construction Soils a*Y,*F TW6, lc=z, • f 4 Vaz> Pt c�,Naa Water Quality Method (Minimum Requirement 6) Under 5,000 sf threshold Water Quantity Method (Minimum Requirement 7) Under 10,000 sf threshold Existing Site Conditions Summary: (Additionally, provide information on previous permits, if any, like Grade and Fill, Clear and Grade, topography, vegetation, drainage, Critical Areas adjacent to the site and how it may affect this project if soils are disturbed, Soils Type (Included in Soils Analysis Report), Erosion Problem Areas, Construction PhasinglSequence ) The is undeveloped with brush and a few.trees. The site slopes from the southeast down to the northwest at about 39/6. Saint Mary's Drive borders the east with a curb and gutter. A single family home lies to the north and undeveloped S Avenue lies to the west. A seasonal creek crosses the south portion of the site flowing from east to west. A 50 foot buffer has been established from the creek to the building structure. The soils analysis is in Appendix 2. Developed Conditions Summary: (Additionally, to be shown on the site plan. Identify cut and fill areas, proposed slopes of all hard surfaces, proposed contours) The site will be developed with two single family homes and driveways to Saint Mary's Drive. Cut and fills will be minor due to the flat site. Contours will not change. Site plan is in Appendix 5. Drainage Basin (2007 Storm Comp Plan —City website\publicworks\engineering\comprehensive plans): What Drainage Basin are you in? F4 Identify any downstream drainage issues (Storm Comp Plan: Yes. If so, describe: This basin discharges to Fidalgo Bay at outfall 42. The basin is large with no issues in the system for over one mile. A recent re-evaluation of the basin from 32"d Street to the Bay with current rain fall criteria showed ample capacity. The system above 32"d Street is largely an open ravine with some enclosed pipes down to and under State Route 20 to R Avenue. The length of drainage system from this site to R Avenue is 3,300 lineal feet. Complete the Applicability Requirements —Flow Chart (Figure I-2.4.1 Attached, Figure I-2.4.2 Attached and Figure I-2.5.1 Attache Version Date: October 7, 2019 Previous Version Date: February 20, 2019 1• Figure 1.2A.'I Flow Chart for Determining Requirements for New Development Start Here Does the site have 35% YQs See Redevelopment Minimum or more of existing Requirements and Flow Chart impervious coverage? (Figure 1-2.4.2). No Does the project convert acres or more of vegetation to Does the project result in lawn or landscaped areas, or 5,000 square feet, or No convert 2.5 acres or more of greater, of new plus Ip native vegetation to pasture? replaced hard surface area? No Yes Yes All Minimum Requirements Minimum Requirements#1 through mo apply to the new and replaced hard surfaces and the land disturbed. Does the project result in 2,000 square feet, I of new plus replaced hard surface area? Does the project have land disturbing activities of 7,000 Yes square feet or greater? No Minimum Requirement#2 applies. Flow Chart far Determining Requirements for New Development DEPARTMENT OF Revised June2015 ECOLOGY Please see httpJMikt lncecy.tva.govlcopyright.htmffor copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 11 2094 StormwaterManagementManual forWestem Washington Volume ! -Chapter 2 -Page 37 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Does the project result in 2,000 square feet, I of new plus replaced hard surface area? Does the project have land disturbing activities of 7,000 Yes square feet or greater? No Minimum Requirement#2 applies. Flow Chart far Determining Requirements for New Development DEPARTMENT OF Revised June2015 ECOLOGY Please see httpJMikt lncecy.tva.govlcopyright.htmffor copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 11 2094 StormwaterManagementManual forWestem Washington Volume ! -Chapter 2 -Page 37 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 1 (MINIMUM REQUIREMENT #1) • 1-2.5. I Minimum Requirement #1 — Prepare a Stormwater Site Plan - 1.3 — Preparation of a Stormwater Site Plan - 1.3.1 — Stormwater Site Plans: Step -by -Step Note: The level of detail needed for each step depends upon the project size. Provide a narrative description of each step. 1-3.1.1 Step 1 -Site Analysis: Collect and Analyze Information on Existing Conditions Site analysis shall be submitted as part of the Existing Conditions Summary above. Part of the information in this step should be used to help prepare the Construction Stormwater Pollution Prevention Plan. Purpose of the Site Analysis is to provide for a Low Impact Development site design that is intended to compliment the predeveloped conditions of the site. A Stormwater site plan has been prepared showing the house/garage, driveways and direction of flow to perforated stub out and storm system. Soils report included in Appendix 2. 1-3.1.2 Step 2 - Prepare Preliminary Development Layout Based upon the analysis of existing site conditions, locate the buildings, roads, parking lots, landscaping features, on -site stormwater management BMP's, and preliminary location of stormwater treatment and retention/detention facilities for the proposed development. See layout included in Appendix 5. 1-3.1.3 Step 3 -Perform Off -site Analysis (at Local Agency's Option): Use additional Sheets, if necessary, Ecology recommends that local governments require an off -site analysis for projects that add 5,000 SF or more of new hard surfaces, or convert 3/ acres of vegetation to lawn or landscape areas, or convert 2.5 acres of forested area to pasture. Off -site analysis extends to'/4 mile downstream of the project site. The site sheets to the northeast and down "S" Avenue. A single family home lies to the north side of the property. A storm system lies along the east side of the property in Saint Mary's Drive under the curb line with a catch basin in the northeast corner of the site. Storm water flows north to Fidalgo Avenue and west 900 feet to the main storm line that flows north just east of Commercial Avenue down the hill and opens to an open ravine for approximately 600 feet before re-entering the closed drainage system to Fidalgo Bay. There are no issues identified in the first'/4 mile before the storm system crosses below State Route 20. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 1-3.1.4 - Determine Applicable Minimum Requirements Establish project size thresholds for the application of Minimum Requirements to new development and redevelopment projects. Figures 2.4.1 (Attached) and 2A.2 (Attached) provide the same thresholds in a flow chart format. Based on the preliminary layout, determine whether Minimum Requirements #1 through #5 apply to the project; or, whether Minimum Requirements #1 through #9 apply. Please note, that Minimum Requirement #1 through #5 may trigger additional Minimum Requirements, such as Flow Control. The total new impervious area added to this site will be 6,571 square feet of new or replaces hard surfacing and over the 5,000 square foot threshold and triggers minimum requirements 1 through 9. 1-3.1.5 Step 5 - Prepare a Permanent Stormwater Control Plan (Refer to this section of the Ecology Manual for requirements.) A storm water plan is provided in the developed site plan in Appendix 5. The report will require Post -Construction soil quality and depth as well as dispersion trenches. 1-3.1.6 Step 6 - Prepare a Construction Stormwater Pollution Prevention Plan (MR#2 — 13 Elements) Refer to Chapter 11-3 —Planning for a detailed description of each element. See also attached Tables 4.1.1 (Source Control BMP's by SWPPP Element) and Table 4.2.1 (Runoff Conveyance and Treatment BMP's by SWPPP Element). See attached 13 Elements of a SWPPP, please complete and attached 1-3.1.7 Step 7 - .Complete the stormwater site plan The Stormwater Site Plan encompasses the entire submittal to the Local Agency with drainage review authority. Refer to this section of the Manual for further clarification of each item and what is required. See below: • Project Overview • Existing Conditions Summary • Off -site Analysis Report • Permanent Stormwater Control Plan • Construction Stormwater Pollution Prevention Plan • Special Reports and Studies • Other Permits • Operation and Maintenance Manual • Declaration of Covenant for Privately Maintained Flow Control and Treatment Facilities. (See attached Drainage BMP Maintenance Covenant BMP Agreement) Version Date: October 7, 2019 Previous Version Date: February 20, 2019 • Declaration of Covenant for Privately Maintained On -site Stormwater BMP's (See attached Drainage BMP Maintenance Covenant BMP Agreement) • Bond Quantities Worksheet, if applicable The project overview has been provided at the beginning of this report along with an existing conditions description. Maps are included in the attachments. 1-3.1.8 Step 8 -Check Compliance with all Applicable Minimum Requirements A Stormwater Site Plan as designed and implemented should speccally fulfill all Minimum Requirements applicable to the project. The Stormwater Site Plan should be reviewed to check that these requirements are satisfied. To take place during review and during and after construction. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ADZ (MINIMUM REQUIREMENT #2) • 1-2.5.2 Minimum Requirement #2 — Construction Stormwater Pollution Prevention Plan (SWPP) All projects are required to complete Minimum Requirement 2. Refer to the 13 Elements of the SWPP (See document below, complete and attach) See attached Table 4.1.1, Table 4.2.1 and Table - Provide Engineering Calculations as an attachment for Sediment Ponds\Traps, Diversions, Waterways and Runoff/Stormwater Detention Calculations. Table 4.1.1 Source Control BMP's by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 BMPorElementliasne Element91 Preserve Vre preserve rk Element62 Establish Construction Elemantl5 StablIbA Saga Element/& Protect Slopes Elemerrii9 Control Pollutants ElamerdlR'11 Maintain BMPs Elementag'I2 Manegethe project Element#13 Protect Low Impact BMP C101: Preserving Natural Vegetation ✓ BMP C102: BuHarZones sf BMP C103: High V4lbllly Plastic or Metal Fence BNP C105: StabllzedConstructlon Entrance f Etdt BNP C106: Wheel Wash ✓ BMP C10T. Construction RoadfParkrtg Area Stabilization UP C120:TenWraryand Permanent Sending BNP C121: Mulching ✓ �/ BLIP C122: Nab and Blenists BNP C123: Plastic Covering ✓ ®MP ClI ; Sodding ✓ BMP C125: TopwllingIComposthg ®MP C120: Pallleerylenide for Sall Erasion protection ®MP C130: Sudan Roughening ✓ �/ BMP C131: GradleatTerraws ✓ t! BMP C140: Dustcontrol ✓ BNP OWN Melerl®Is on Hard e/ ✓ ®MP C1511 Concrete Handling ✓ BNP C1521 Saamutting end SurlochN Pollution Prevention BMP C153: Malsrinl Delivery, Slorage and Containment BMP CiS1a Concrete WhshoutArea a/ ®MPC1g0: CertlindErosion and Sediment Control Lead ve BMP CIO Schsduing Table 4.2.1 Runoff Conveyance and Treatment BMP's by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 -- Llement43 Elnmentift ElenerANB Elan*nLH7'; 6 Elerrtenl55 E#err rrtf00 Elelmflt#fD Elemant f"3 131015 cVlowrANum Control ttratall Not9nt Phabgr $IeGill�$ Contml GarnbulDfla F'toleCktn4r FInwRatas Sedtroant slopes Oralnl�ls� Channals PaMul**s Vralerov IMPach �.a rala I and outlelrs avo-1 renE F W F iC WO. lnlar etpt& Dlka .and SvmlQ d ,� 19A(P CZK& Gta #.1 aed Ch3niials EMP 0292rg Chwrrel Utfam RMP CM; VftWr Dam Ve ,f I• 6MP C204; Pipo Slope Drams �{ . �1p,P C20$; g#r�tRih� �ralRs +f SMP C306, Level 9prmdrrr BMPC207:j Chock Cans ! BW+;200; Xraan9ulzrt�9lt�rtt�t[i�6Mex1�4 y Enaeeud Cheek fkamj amp G200: f1umat PYatcalian ISMP G=1 Moan Drain Inlet Frdtoclion, ,7 ampC231. Brusfi®wAor Vr BMP C292; Gravel Mll*v D*rm ampc"14 SdtFOPCe ve ,t 6MP+C234; Wgel"Strip ,rr 13MP C23& Wattles BMPG238:' V991tetlye Filtration v' �MP�2 SodWranRTr� ,f �' 13MPC21.1: Temptrrary S rot Pond 13MP C25W Canatrluifnh Starmtataier Gt�ic+ii tra®t Ve SMP C2&t:Coltrabudon Starrrr,wdfir — FlpraU�an ' LAMP C252' FIl11h pH Neuiraftallon Using C13- ' OMP 023: pH 06n0o! fQr Nigh Fill! Mtnr 13 Elements of SWPPP Version Date: October 7, 2019 Previous Version Date: February 20, 2019 (Construction Stormwater Pollution Prevention Plan) Please check off boxes to show that each element has been read and understood. Provide details where applicable and if certain aspects are unnecessary or exempt, clearly justify. Details of the 13 Elements and the correlating BMPs are listed Above from the 2014 Stormwater Management Manual for Western Washington (SWMMWWW). A link is provided on the City of Anacortes website, under Planning, Community, & Economic Development Department, as well as under Stormwater on the Engineering Division of Public Work's page. Owner Name: Kendall, Site Address Prepared By: 4008 & 4010 Saint Mary's Drive _Dale Herrigstad PE The Stormwater checklist or building permit determined that: ❑ The 13 elements must be addressed for construction activity adding under 2,000 sq, ft, of hard surface area. ❑ These elements must be addressed for construction activity adding 2,000 sq. ft. or more of hard surface area. This means that an attached narrative and site plan are required with this document. Under each element, provide the BMP's that will be applicable to your project. Use the attached Tables provided. ELEMENT 1: Preserve Vegetation/Mark Clearing Limits ❑ Before beginning land disturbing activities, including clearing and grading, clearly mark all clearing limits, sensitive areas and their buffers, and trees that are to be preserved within the construction area. ❑ Retain the duff layer, native top soil, and natural vegetation in an undisturbed state to the maximum degree practical. A high visibility construction fence BMP C103 will be installed at the perimeter of the construction site and along the 50 foot creek buffer. BMP C233, Silt Fence will also be used to mark the down slope perimeter of the construction site. BMP to be monitored daily and repaired as needed. ELEMENT 2: Establish Construction Access ❑ Limit construction vehicle access and exit to one route, if possible. ❑ Stabilize access points with a pad of quarry spalls, crushed rock, or other equivalent BMPs, to minimize tracking onto roads. ❑ Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in preventing tracking sediment onto roads. ❑ If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary (ex: wet weather). Remove sediment from roads by shoveling, sweeping, or pick up and transport the sediment to a controlled sediment disposal area. ❑ Conduct street washing only after sediment is removed in accordance with the above bullet. ❑ Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. The construction entrance located at Saint Mary's Drive with a gravel pad as BMP C105 or C107 (Construction Entrance). Temporary construction parking will likely utilize S Avenue due to no parking available on Saint Mary's Drive due to the narrow road. The temporary parking will utilize a Version Date: October 7, 2019 Previous Version Date: February 20, 2019 crushed rock pad that will be removed after construction is completed. S Avenue is a gravel road to Fidalgo Avenue. Any dirt or mud that is tracked onto the roadway will be clean immediately. ELEMENT 3: Control NOW Rates ❑ Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the velocity and peak volumetric flow rate of stormwater runoff from the project site. ❑ Where necessary to comply with the bullet above, construct stormwater retention or detention facilities as one of the first steps in grading. Assure that detention facilities function properly before constructing site improvement (e.g, impervious surfaces). ❑ If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. A temporary sediment trap will be constructed on site to slow off site sheet flow. ELEMENT 4: Install Sediment Controls ❑ Design, install, and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. ❑ Construct sediment control BMPs (sediment ponds, traps, filters, etc.) as one of the first steps in grading. These BMPs shall be functional before other land disturbing activities take place. ❑ Minimize sediment discharges from the site. The design, installation and maintenance of erosion and sediment controls must address factors such as the amount, frequency, intensity and duration of precipitation, the nature of resulting stormwater runoff, and soil characteristics, including the range of soil particle sizes expected to be present on the site. ❑ Direct stormwater runoff from disturbed areas through a sediment pond or other appropriate sediment removal BMP, before the runoff leaves a construction site or before discharge to an infiltration facility. Runoff from fully stabilized areas may be .discharged without a sediment removal BMP, but must meet the flow control performance standard in Element #3, bullet #1. ❑ Locate BMPs intended to trap sediment on -site in a manner to avoid interference with the movement of juvenile salmonids attempting to enter off -channel areas or drainages. ❑ Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal, and maximize stormwater infiltration. ❑ Where feasible, design outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column. Per BMP C233 a silt fence will be installed along the downslope perimeter of the site along the north and west boundary. To be installed prior to the start of construction. BMP to be monitored daily and repaired as needed. BMP C162 Scheduling. ELEMENT 5: Stabilize Soils ❑ Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs include, but are not limited to: temporary and permanent seeding, sodding, mulching, plastic covering, erosion control fabrics and matting, soil application of polyacrylamide (PAM), the early application of gravel base early on areas to be paved, and dust control. ❑ Control stormwater volume and velocity within the site to minimize soil erosion. ❑ Control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. ❑ Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion. o During the dry season (May 1 — Sept 30): 7 days o During the wet season (Oct 1 — Apr 30): 2 days Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ❑ Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. ❑ Stabilize soil stockpiles from erosion, protect with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. ❑ Minimize the amount of soil exposed during construction activity. ❑ Minimize the disturbance of steep slopes. ❑ Minimize soil compaction and, unless infeasible, preserve topsoil. Stabilize exposed and un-worked soils by application of effective BMPs that prevent erosion. Applicable BMPs include, but are not limited to: temporary and permanent seeding, sodding, mulching and plastic covering. Install plastic covering per BMP C123 on Soils Stockpiles. BMP to be monitored daily and repaired as needed. Refer to Table 4.1.1 in MR #2. ELEMENT 6: Protect Slopes ❑ Design and construct cut -and -fill slopes in a manner to minimize erosion. Applicable practices include, but are not limited to, reducing continuous length of slope with terracing and diversions, reducing slope steepness, and roughening slope surfaces (Ex: track walking). ❑ Divert off -site stormwater (run-on) or ground water away from slopes and disturbed areas with interceptor dikes, pipes, and/or swales. Off -site stormwater should be managed separately from stormwater generated on the site. ❑ At the top of slopes, collect drainage in pipe slop drains or protected channels to prevent erosion. o *Temporary pipe slope drains must handle the peak volumetric flow rate calculated using a 10- minute time step from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate predicted/indicated by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis must use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the Western Washington Hydrology Model (WWHM) to predict flows, bare soil areas should be modeled as "landscaped" area. o Where 15-minute time steps are available in an approved continuous runoff model, they may be used directly without a correction factor. ❑ Place excavated material on the uphill side of trenches, consistent with safety and space considerations. ❑ Place check dams at regular intervals within constructed channels that are cut down a slope. ❑ Consider soil types and its potential for erosion. ❑ Stabilize soils on slopes, as specified in Element 5. ❑ BMP combinations are the most effective method of protecting slopes with disturbed soils. Ex: Use both mulching and straw erosion control blankets. The site has an average slope of less than 3% across the entire site. Steeps slopes are not a concern. ELEMENT 7: Protect Drain Inlets ❑ Protect all storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Clean or remove and replace inlet protection devices when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer). ❑ Where possible, protect all existing storm drain inlets so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. ❑ Keep all approach roads clean. Do not allow sediment and street wash water to enter storm drains without prior and adequate treatment unless treatment is provided before the storm drain discharges to Version Date: October 7, 2019 Previous Version Date: February 20, 2019 waters of the State. ❑ Inlets should be inspected weekly at a minimum and daily during storm events. Per detail 140.20-00 Storm Drain Inlet protection devices will be installed at existing catch basins in the immediate vicinity of the project. To be installed prior to the start of any construction. Nearest CB is north of the proposed entry to the site is just north of the northwest corner of the site in Saint Mary's Drive. BMP to be monitored daily and repaired as needed. ELEMENT 8: Stabilize Channels and Outlets ❑ Design, construct, and stabilize all on -site conveyance channels to prevent erosion from the following expected peak flows: o *Channels must handle same peak volumetric flow rate as temporary pipe slope drains listed in Element 6, above. ❑ Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent streambanks, slopes, and downstream reaches at the outlets of all conveyance systems. ❑ The best method for stabilizing channels is to completely line the channel with a blanket product first, then add check dams as necessary to function as an anchor and to slow the flow of water. No stormwater runoff will be conveyed off site via channels, swales, or streams. ELEMENT 9: Control Pollutants ❑ Design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants. ❑ Handle and dispose of all pollutants, including waste materials and demolition debris that occur on -site in a manner that does not cause contamination of stormwater. ❑ Provide cover, containment, and protection from vandalism for all chemicals, liquid products, petroleum products, and other materials that have the potential to pose a threat to human health or the environment. On -site fueling tanks must include secondary containment. Secondary containment means placing tanks or containers within an impervious structure capable of containing 110% of the volume contained in the largest tank within the containment structure. Double -walled tanks do not require additional secondary containment. ❑ Conduct maintenance, fueling, and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. ❑ Discharge wheel wash or tire bath wastewater to a separate on -site treatment system that prevents discharge to surface water, such as closed -loop recirculation or upland land application, or to the sanitary sewer, with local sewer district approval. Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. ❑ Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of chemical to stormwater runoff. Follow manufacturers' label requirements for application rates and procedures. ❑ Use BMPs to prevent contamination of stormwater runoff by pH -modifying sources. The sources for this contamination include, but are not limited to: bulk cement, cement kiln dust, fly ash, new concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete pumping, and mixer washout waters. Adjust the pH of stormwater if necessary to prevent violations of the water quality standards. ❑ Assure that washout of concrete trucks is performed off -site or in designated concrete washout areas only. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Do not use upland land applications for discharging wastewater from concrete washout areas. ❑ Obtain written approval from Ecology and provide to the City before using chemical treatment other than CO2 or dry ice to adjust pH. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 ❑ Woody debris may be chopped and spread on site. ❑ Conduct oil changes, hydraulic system drain down, solvent and de -greasing cleaning operations, fuel tank drain down and removal, and other activities which may result in discharge or spillage of pollutants to the ground or into stormwater runoff using spill prevention measures, such as drip pans. ❑ Clean contaminated surfaces immediately following any discharge or spill incident. Emergency repairs may be performed on -site using temporary plastic placed, beneath and, if raining, over the vehicle. Per BMP C154 a Concrete Washout Area is to be installed onsite to capture contaminated water from concrete washouts. To be installed prior to foundation / concrete installation. BMP to be monitored daily and repaired as needed. Contractor is to provide spill prevention kits for excavation and concrete crews are required on Site. ELEMENT 10: Control De -Watering ❑ Discharge foundation, vault, and trench dewatering water, which have characteristics similar to stormwater runoff at the site, into a controlled conveyance system before discharge to a sediment trap or sediment pond. ❑ Discharge clean, non -turbid de -watering water, such as well -point ground water, to systems tributary to, or directly into surface waters of the State, as specified in Element 8, provided the de -watering flow does not cause erosion or flooding of receiving waters or interfere with the operation of the system. Do not route clean dewatering water through stormwater sediment ponds. Note that "surface waters of the State" may exist on a construction site as well as off site; for example, a creek running through a site. ❑ Handle highly turbid or contaminated dewatering water separately from stormwater. ❑ Other treatment or disposal options may include: 1. I nfiltration 2. Transport off -site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute state waters. 3. Ecology -approved on -site chemical treatment or other suitable treatment technologies. 4. Sanitary or combined sewer discharge with local sewer district approval, if there is no other option. 5. Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized dewatering. ❑ Construction equipment operation, clamshell digging, concrete tremie pour, or work inside a cofferdam can create highly turbid or contaminated dewatering water. ❑ Discharging sediment -laden (muddy) water into waters of the State likely constitutes a violation of water quality standards for turbidity. The easiest way to avoid discharging muddy water is through infiltration and preserving vegetation. If dewatering is needed all discharge will be directed to a temporary sediment trap BMP C240 prior to discharge to the city storm drainage system. The sediment trap will be designed for a typical 4,000 sf impervious area or 0.09 acres where the developed 2 year flow is 0.03 cfs X 2080 sf/cfc flow = 62 sf surface area plan or 8'x8' square surface pond area minimum. ELEMENT 11: Maintain BMPs ❑ Maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to assure continued performance of their intended function in accordance with BMP specifications. ❑ Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed. Some temporary erosion and sediment control BMPs are bio-degradable and designed to remain in place following construction such as compost socks. ❑ Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction. All BMPs that are to remain in place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the BMPs during construction, it shall be removed and the facility shall be returned to the conditions specified in the construction Version Date: October 7, 2019 Previous Version Date: February 20, 2019 documents. ❑ Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. BMP to be monitored daily and repaired as needed and or as required by the City of Anacortes. Weekly reports are required to be submitted to the building department. ELEMENT 12: Manage the Project —Projects subject to Minimum Requirements 1-9 must have a Certified Erosion and Sediment Control Lead (CESCL) for site inspections. Projects subject to Minimum Requirements 1-5 do not require the inspector to be certified. By the initiation of construction, the SWPPP must identify the CESCL or inspector, who shall be present on -site or on -call at all times. ❑ Phase development projects to the maximum degree practicable and take into account seasonal work limits to prevent soil erosion and prevent transporting sediment from the site during construction. ❑ Inspection and monitoring — Inspect, maintain, and repair all BMPs as needed to assure continued performance of their intended function. ❑ Maintain, update, and implement the SWPPP. ❑ Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g., subdivision approval). ❑ From Oct 1 through Apr 30, clearing, grading, and other soil disturbing activities is permitted only if shown that the site operator will prevent silt -laden runoff from leaving the site through a combination of the following: 1. Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters. 2. Limit activities and the extent of disturbed areas. 3. Proposed erosion and sediment control measures. Weather conditions can influence the seasonal limitation on site disturbance. The City of Anacortes has the authority to take enforcement action per AMC 19.76 Stormwater. ❑ The following activities are exempt from the seasonal clearing and grading limitations: 1. Routine maintenance and necessary repair of erosion and sediment control BMPs; 2. 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 3. Activities where there is 100% infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. BMP to be monitored daily and repaired as needed and the responsibility of the owner. Project does not requires a certified CESCL. ELEMENT 13: Protect Low Impact Development BMPS ❑ If implementing any bioretention facilities or rain gardens, refer to the applicable BMP sections of the Manual for requirements. No LID BMPS are proposed. _Dale Herrigstad Applicant Signature July 28, 2021 Date Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 3 (MINIMUM REQUIREMENT #3) • 1-2.5.3 Minimum Requirement #3 — Source Control of Pollution All known, available and reasonable source control BMP's must be applied to all projects. Source control BMP's must be selected, designed, maintained according to the reference Ecology Manual. The intent of source control BMP's is to prevent stormwater from coming in contact with pollutants. They are a cost-effective means of reducing pollutants in stormwater, and, therefore, should be considered in all projects. Single Family Residential Construction Projects and Residential Subdivisions are Exempt from this Minimum Requirement. All Commercial Properties, Industrial Properties, and Multi -Family Properties, Boatyards, Sand and Gravel Mining Opertations are required to comply with this Minimum Requirement. Refer to Chapter IV-2.1 Applicable (Mandatory) Operationsal Source Control BMP's Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 4 (MINIMUM REQUIREMENT #4) • Minimum Requirement #4 —Preservation of Natural Drainage Systems and OutfCa 0 Natural drainage patterns shall be maintained and discharges from the project shall occur at the natural location, to maximum extent practicable. The manner by which runoff is discharged from the project site must not cause a significant adverse impact to downstream receiving waters and down gradient properties. All outfalls require energy dissipation. The objective is to preserve and utilize drainage systems to the fullest extent because of the multiple stormwater benefits these systems provide; and to prevent erosion at the downstream of the discharge location. Refer to the reference manual for supplemental guidelines and additional information under this section. Will this project disturb the Natural Drainage System or Outfall of the project Site? No. If yes, refer to section 1.2.5.4 for Supplemental Guidelines for additional information. No change in drainage is proposed for this site. Drainage will connect to the storm system in the adjacent road. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 5 (MINIMUM REQUIREMENT #5) • Minimum Requirement #5 — On -site Stormwater Management Project thresholds that trigger Minimum Requirements #1 through #5, shall utilize the On -site Stormwater Management BMP's from List #1 for all surfaces within each type of surface in List #1; or, Demonstrate compliance with the LID Performance Standard. Projects selecting this option cannot use Rain Gardens. They may choose to use Bioretention BMP3s as described in Chapter V-7 — Infiltration and Bioretention Treatment Facilities to achieve the LID Performance Standard. Refer to this section of the reference Manual for all Feasibility or Infeasibility Criteria for List #1 and List #2. Is this project Flow Control Exempt? No (See Appendix I-E: Flow Control -Exempt Surface Water). If yes, provide reasoning from the applicability section of 1-2.5.7 Minimum Requirement #7: Flow Control). If No, then the project triggers Minimum Requirement #7 (1-2.5.7) and possibly Minimum Requirement #8 (1-2.5.8). All sites are required to utilize BMP T5.13 —Post Construction Soil Quality and Depth. For each surface, consider the BMP's in the order listed for that type of surface. Use the first BMP that is considered feasible. No other on -site Stormwater Management BMP is necessary for that surface. Feasiblity shall be determined by evaluation against: 1. Design criteria, limitations and infeasiblity criteria identified for each BMP in this manual, and; 2. Competing needs criteria listed in Chapter V-5 — On -site Stormwater Management. Lawn and Landscaped Area: • BMP T5.13: Post -Construction Soil Quality and Depth. (Attach Detail in Report) Refer to this site for requirements and specifications. All projects are required to utilize this BMP. http://www.soilsforsalmon.org/pdf/Soil BMP Manual.pdf See Appendix 3 for the "Model Soil Management Plan for BMP T5.13" to be submitted with Drainage Report and Application Material. An alternate document acceptable to the City of Anacortes is a Test Report provided by the Soils Supplier that identifies the soils to be used meet the specifications outlined under Minimum Requirement 5. The specifications are in both WSDOT and CSI Formats. For specifications, refer to the above referenced PDF. This submittal can be a deferred submittal since most projects are not sure who the supplier will be at the time of building permit application. For projects that trigger Minimum Requirements 1 through 5, the Test Report will be provided to the Building Department. Projects triggering Minimum Requirements 1 through 9, the Test Report will be provided to the Engineering Department, BMP List #1 Roofs: (Provide feasible detail and maintenance and operations specifications in the report) 1. BMP T5.30: Full Dispersion: Infeasible, explain the criteria: Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Requires native vegetation on site and there is no native vegetation on this site. Or, T5.10A: Downspout Full Infiltration: Infeasible The soils report identifies the perched water table at a depth of 19 to 20 and not feasible for infiltration that requires a depth of 40" minimum. 2. BMP T5.14A: Rain Gardens is Infeasible. If infeasible, explain the criteria: The rain garden requires 12" separation to the perched water table and is not feasible for this site Or, BMP T7.30: Bioretention Cells, Swales, and Planter Boxes Feasible\Infeasible If infeasible, explain the criteria: The Bioretention cell requires 12" separation to the perched water table and is not feasible for this site 3. BMP T5.10B: Downspout Dispersion Systems: Infeasible If infeasible, explain the criteria: Dispersion requires a minimum of 25 feet of dispersion area and only 20 feet of setback is provided to the house and property line. 4. BMP T5.10C: Perforated Stub -out Connections; Feasible If infeasible, explain the criteria: Perforated stub outs will be provided between the house and the catch basin in the northeast corner of the site at Saint Mary's Drive. The catch basin is 5 feet deep and will easily drain the roof and footings. Other Hard Surfaces: (Provide feasible detail and maintenance and operations specifications in the report) The driveway surface area is 500 square fee. 1. BMP T.5.30 Full Dispersion Feasible\Infeasible If infeasible, explain the criteria: Requires native vegetation on site and there is no native vegetation on this site. 2. BMP T5.15: Permeable Pavements: Infeasible If infeasible, explain the criteria: Requires 12" separation to the perched water table and is not feasible for this site. Or, BMP T.14.A: Rain Gardens: Infeasible If infeasible, explain the criteria: Requires 12" separation to the perched water table and is not feasible for this site. Or, BMP T7.30: Bioretention Cells, Swales and Planter Boxes Feasible\Infeasible Requires 12" separation to the perched water table and is not feasible for this site. 3. BMP T5.12: Sheet Flow Dispersion: Infeasible If infeasible, explain the criteria: The driveway is within 7 feet of the north property line and not area for dispersion. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Or, Es T5.11: Concentrated Flow Dispersion: Infeasible If infeasible, explain the criteria: The driveway is within 7 feet of the north property line and not area for dispersion. The driveway water will sheet to the gutter line and to the catch basin just north of the entrance point in Saint Mary's Drive Dale Herrigstad icant Si July 28, 2021 Date Version Date: October 7, 2019 Previous Version Date: February 20, 2019 BMP T5.13: Post -Construction Soil Quality and Depth Purpose and Definition Naturally occurring (undisturbed) soil and vegetation provide important stormwater func- tions including: water infiltration; nutrient, sediment, and pollutant adsorption; sediment and pollutant biofiltration; water interflow storage and transmission; and pollutant decom- position. These functions are largely lost when development strips away native soil and vegetation and replaces itwith minimal topsoil and sod. Not only are these important stormwater functions lost, but such landscapes themselves become pollution generating pervious surfaces due to increased use of pesticides, fertilizers and other landscaping and household/industrial chemicals, the concentration of pet wastes, and pollutants that accompany roadside litter. Establishing soil quality and depth regains greater stormwater functions in the post devel- opment landscape, provides increased treatment of pollutants and sediments that result from development and habitation, and minimizes the need for some landscaping chem- icals, thus reducing pollution through prevention. Applications and Limitations Establishing a minimum soil quality and depth is not the same as preservation of nat- urally occurring soil and vegetation, however, establishing a minimum soil quality and depth will provide improved on -site management of stormwater flow and water quality. Soil organic mattercan be attained through numerous materials such as compost, com- posted woody material, biosolids, and forest product residuals. it is important that the materials used to meet the soil quality and depth BMP be appropriate and beneficial to the plant coverto be established. Likewise, it is important that imported topsoils improve soil conditions and do not have an excessive percent of clay fines. This BMP can be considered infeasible on till soil slopes greater than 33 percent. Design Guidelines . Soil retention. Retain, in an undisturbed state, the duff layer and native topsoil to the maximum extent practicable. In any areas requiring grading remove and stock- pile the duff layer and topsoil on site in a designated, controlled area, not adjacent to public resources and critical areas, to be reapplied to other portions of the site where feasible. . Soil quality. All areas subject to clearing and grading that have not been covered by impervious surface, incorporated into a drainage facility or engineered as struc- tural fill or slope shall, at project completion, demonstrate the following: 1. A topsoil layer with a minimum organic matter content of 10% dry weight in planting beds, and 50/6organic matter content in turfiareas, and a ph from 6.0 2014 StormwaterManagementManual for�Westem Washington Volume V -Chapter 5 -Page 99 9 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 to S.0 or matching CH of the undisturbed soil. The topsoil layer shall have a minimum depth of eight inches except where tree roots limit the depth of incorporation of amendments needed to meet the criteria. Subsoils below the topsoil layer should be scarified at least 4 inches with some incorporation of the upper material to avoid stratified layers, where feasible. 2. Mulch planting beds with 2 inches of organic material 3. Use compost and other materials that meet these organic content require- ments: a. The organic content for "pre -approved" amendment rates can be met only using compost meeting the compost specification for BMP T7.30: Bioretention Cells, Swales, and Planter Boxes (p.959), with the excep- tion that the compost may have up to 35% biosolids or manure. The compost must also have an organic matter content of 40% to 65%, and a carbon to nitrogen ratio below 25:1. The carbon to nitrogen ratio may be as high as 35:1 for plantings com- posed entirely of plants native to the Puget Sound Lowlands region. b. Calculated amendment rates may be met through use of composted material meeting (a.) above; or other organic materials amended to meet the carbon to nitrogen ratio requirements, and not exceeding the contaminant limits identified in Table 220-13, Testing Parameters, in WAC 173-350-220. The resulting soil should be conducive to the type of vegetation to be established. . Implementation Options: The soil quality design guidelines listed above can be met by using one of the methods listed below: 1. Leave undisturbed native vegetation and soil, and protect from compaction during construction. 2. Amend existing site topsoil or subsoil either at default "pre -approved" rates, or at custom calculated rates based on tests of the soil and amendment. 3. Stockpile existing topsoil during grading, and replace it prior to planting. Stockpiled topsoil must also be amended if needed to meet the organic mat- ter or depth requirements, either at a default if pre -approved rate or at a cus- tom calculated rate. 4. Import topsoil mix of sufficient organic content and depth to meet the require- ments. 2094 StormwaterManagementManuat forWesterra Washington Volume V -Chapter 5 -Page 9 92 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 More than one method may be used on different portions of the same site. Soil that already meets the depth and organic matter quality standards, and is not com- pacted, does not need to be amended. Planning/Permitting/InspectionNerification Guidelines & Procedures Local governments are encouraged to adopt guidelines and procedures similar to those recommended in Guidelines and Resources For Implementing Soil Quality and Depth BMP T5.13 in WDOE Stormwater Management Manual for Western Washington. This document is available at: http://www,soilsforsalmon.org/pdf/Soil BMP Manual.pdf Maintenance . Establish soil quality and depth toward the end of construction and once estab- lished, protect from compaction, such as from large machinery use, and from erosion. . Plant vegetation and mulch the amended soil area after installation. Leave plant debris or its equivalent on the soil surface to replenish organic matter. . Reduce and adjust, where possible, the use of irrigation, fertilizers, herbicides and pesticides, rather than continuing to implement formerly established practices. Runoff Model Representation Areas meeting the design guidelines may be entered into approved runoff models as "Pasture" rather than "Lawn, Flow reduction credits can be taken in runoff modeling when BMP T5.13: Post -Con- struction Soil Quality and Depth is used as part ofa dispersion design under the con- ditions described in: . BMP T5.106: Downspout Dispersion Systems (p.905) BMP T5.11: Concentrated Flow Dispersion (p.905) . BMP T5.12: Sheet Flow Dispersion (p.908) BMP T5.18: Reverse Slope Sidewalks (p.937) . BMP T5.30: Full Dispersion (p.939) (for public road projects) 2094 5tormwaterManagementManual for Western Washington Volume V -Chapters -Page 993 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Figure V05.3.3 Planting bed Cross -Section Mulch tl Loose soil with " visible dark :r organic matter 4" 1 Loose or fractured subs6l Reprinted from Cuirletines arc! Resources For Implementing Soil Quality and Depth SAIP T5.13 in WDOE Stormwater Management Manual for Western Washington, 2010, Washington Organic Recycling Council NOT TO SCALE Figure V-5,3.3 Planting Bed Cross -Section DEPART Revised January 20153 ECOLOGY Please see httpAvA% .ecy.wa.gou/copyright.htmifor copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2094 StormwaterManagemenfManual for Western Washingfon Volume V -Chapters -Page 994 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 area. Figure 111-3.1.8 Perforated Stub -Out Connection random fill filter fabric Ned 3 ji 18" min, T 4" perf pipe 1 %" %" washed rock 24" min. Trench X-Section slope to road drainage system 2' x 10' level trench w/perfpipe Plan View of Roof NOT TO SCALE stub Figure III-3.1.8 qVW Perforated Stub -Out Connection DEPARTMENT OF Revised December2015 ECOLOGY Please see htip:/Atiww.ecy,"a.gov/copyright,htmlfor copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 201 � Stormwater Management Manual for Westetr� Washington Volume Ill -Chapter 3 -Page 466 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 6 — (MINUMUM REQUIREMENT 6 - RUNOFF TREATMENT) Refer to 1.2.5.E and provide the required information for this Minimum Requirement. Threshold requirements for determining the applicability of runoff treatment. Projects in which the total of pollution -generating hard surface (PGHS) is 5,000 square feet or more in a threshold discharge area of the project, or Projects in which the total of pollution -generative pervious surfaces (PGPS)-not including permeable pavements -is three-quarters (3/4) of an acre or more in a threshold discharge area, and from which there will be a surface discharge in a natural or man-made conveyance system from the site. The total PGHS projected for this site is 1,009 square feet of paved driving surface and less than the 5,000 square foot threshold. Treatment is not required. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 TAB 7 — (MINUMUM REQUIREMENT 7 — FLOW CONTROL) Refer to 1.2.5.7 and provide the required information for this Minimum Requirement. Threshold requirements for determining the applicability of flow control. Projects in which the total of effective impervious surfaces is 10,000 square feet or more in a threshold discharge area, or Projects that convert 3/4 acres or more of vegetation to lawn or landscape, or convert 2.5 acres or more of native vegetation to pasture in a threshold dis-charge area, and from which there is a surface discharge in a natural or man-made conveyance system from the site, or Projects that through a combination of effective hard surfaces and converted vegetation areas cause a 0.10 cubic feet per second increase in the 100-year flow frequency from a threshold discharge area as estimated using the Western Washington Hydrology Model or other approved model and one -hour time steps (or a 0.15 cfs increase using 15-minute time steps). The total impervious area is 6,571 square feet and below the 10,000 square foot threshold. This site is FLOW CONTROL EXEMPT. TAB 8 — (MINUMUM REQUIREMENT 8 —WETLAND PROTECTION) Refer to 1.2.5.8 and provide the required information for this Minimum Requirement. There are no wetlands down stream of this site before discharge to the Fidalgo Bay. TAB 9 — (MINUMUM REQUIREMENT 9 —OPERATION AND MAINTENANCE) Refer to 1.2.5.9 and provide the required information for this Minimum Requirement. There are no maintenance requirements for a perforated stub out. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 1 — Boundary Survey 40' O I m I � I CY) BLOCK 15 I Cu j S 88125129' E 102,14' i ROS AF #201810300047 _ o � / R w Lo CN OWN cli m LOT A -- -- -- I > Co O i 7,150 SF oj CN Cu Cu0 a I S 88.251090' E 102,26' e 30' I 30, LOT B 6,798 SF - - - UPLAND AREA 10,502 SF TOTAL 10 oCu 40' Cu W I � m I C4 40,00' 40,01' S 88.24136' E n 3Co 11 c�u O%nj 4 k� 81.06' 143' 24,10` S 88'24'36' E 92,49' GRAPHIC SCALE 15 0 15 30 60 ( IN FEET ) 1 inch = 30 ft. HERRIGS'TAD ENGINEERING &SURVEYING 4320 i�STLE LAKE ROAD ANACORTI+�S, �FA 98221 299-8804 PROPOSED BLA Saint Mary's Drive February 18, 2021 APPENDIX 2 — Soils Report Soils Report Linda Spicher, Septic System Designer License 5100294 (360)708-3004 Project/Client: Keystone Building Services Contact: Kris Yuan Site Address: Proposed Lot B, NHN Stain Mary's Drive, Anacortes1 WA Parcel Number: 58$74, in process of Boundary Line Adjustment Date on Site: 6129/21 Page / of �r� Map Unit, Natural Resources Conservation Service: 78 -Keystone loamy sand, 0 to 8% slopes Hydrologic Soil Group: A Soil Type' Loading Rate2 Soil Log 1 0 —19 brown medium sandy loam 4 0.6 19 — 32 tan medium sandy loam, mottles 4 0.6 32 — 35 brown medium sandy clay loam, dense 5 0.4 35 — 54 tan medium sand, roots, mottles 3 0.8 anticipated perched water table at 19" Soil Log 2 0 — 20 brown medium sandy loam 4 0.6 20 — 48 tan loamy medium sand, roots, mottles 3 0.8 anticipated perched water table at 20" � One of seven numerical classifications of fine earth particles and rock fragments as described in WAC 247-272A-0220 (2)(e). z From Chapter 247-272A WAC: "Hydraulic Loading Rate" means the amount of effluent applied to a given treatment step, in this chapter expressed as gallons per square foot per day (gal/sq. ft./day). w w z o� c wrZ m a W- u3. >- > m>Q NZ O <[> N> CD rn W M> m E 7� m0 ¢ M> r M (1) IX ou �ri o? xW I w �t7 m U) W N J IY U UW t�� cD�>> ❑ �' tj �t T F F t%�vmo U)- W ir Z) W N N W T :r U W r m v_ v 0 e., zU zu �_ MCl) ga)U)(L $x UP3Z:Q.,�...;� W ro to r c= U) 'N he L) UP) m cmNU)iii Fm a�cMifZa U w rnseU NJ n S U yYQ d `° F- QU� W d'l�i.l W S }i > co co W U U ZQ. _� i m 2cp ❑ Q V_ ❑ 1 w _- W r = ❑ nOz CL � O ui �R 7r 2 W �� r F J > M w w U x S / coJ �pQ C,3 w 7 0❑ (Y r< W 00LL] 0 e4 j i� �W Qw ❑- Z iv � _ a)a mU �LL4tiw LwL W Mo0D NZ �❑ W M> n> z Gf j t� LL LL M� � a Q M U a perp, Z M �> t`JZ �' V ❑ \._ ¢ r ❑9 W Z-- - - ...mot._ -b'_ M �"' 1: _- - LL Q LU _❑ M� m� c0'i� M� v� coa¢ v-zoa oQ r> r> <f* J o��b W?� W ma °;� ❑ ' �Q 5 z F. o> w LL W' a w o w rna coLa = Q> QW > �Qof �a �¢ row. _-- - t CD W ct Q >MAC3 m C7 rn t;4W 7 In Z Q aroC1Q mi ¢ .�I' pa. - Q nU OCK .40 w- -w� S a ag LU >D W O NON S > a1'� 2 =ZLLZj wr�iU MUm0 Oo0 a0 _ �U OQ�W �'�QN J wd vJ M>aQ M¢ �rM 0 (.9`9 O� Q c0 `r 4 U cn I;;< F--xO Z m>��>CN Lu U 0Z I ozs tl Z W 2 rW ` 0z J0F J U z r- 7 r F U J O 0c (L. w Lcj Cd U rZ o(D i ^� —oQW �w oW 4DWo U � z t � z � W � -.r .,,:,r. t� I Y I Y w .- - K CCw 4❑ N �d N � O M vw o co 2 oa > \� Of g J Q �LLA � J M�Q M d n4. v a w w Z w �¢ 'or or �ix C W Q Z a ir o cd C) � W r Q 7 > co W --� u7 > w W �¢--a oQ S %T m w a c> fir¢ d�R VEX �w oS �Z W LI Version Date: October 7, 2019 Previous Version Date: February 20, 2019 �o >- w F ;zry .2 a� 6 N cD N CDQ$� iu c nbEb $ A? m e a ra m oluto c; II o a a W e t3 e m Q c ` 20 m y m o g�€me W FLDa as c 0 U) e � a L m O �t `a e � e n �1 rro eri�w AO'6CI OSY2.2 S (LREX I Ch zr- i tT� � _ w >I ! I wi.J�-�li w �— a JIB I i wz'-'O�z IU <cI j Elf Q I� IN wa Al OkVNA M pia ,sesn A .6are.6a C. U a 3/�I21Q S,.l2JyN 1NI'dS j i s lay j O ~ J I s ' a I yo � I �_ RI m�Qo i I � J .B6'24 %'62 •165C A .6ZrIE.2 S J A .LZ.{E. S .WOI 3 .4EY2.64 S I I 0S. m - - - -- - I Je I tiY �� I C11 I CL c4�i I RI I N I P' j� f' -I- -- - `� ` - - -- ----------1 I I RI I ('J Version Date: October 7, 2019 Previous Version Date: February 20, 2019 0�3 woa z ppqad � s�Y N m�li 2 In Z� W I ��0 w C v wo wo ,4S t m O J �s 30N3111s31i 11V97N3� NV id 3dd�SONVq'8 H11S y" a W �3i 3AItl0 S,Atlyyy.WIV9 �� OM I it's Free eel 8/ arm� (J� e W:S3gef��# �tf istt�{sg}l d=� Zs";5 11RCgg#gat a ,ge7pg41aag s� o?'s 9t�S3}yh j ��p'e�di�• 87 t?:1 sett Si�� r 6 anN�yv,s, 's E �a �pfgq t t €sarf, kxjl Eii p�1y C Version Date: October 7, 2019 Previous Version Date: February 20, 2019 `T M &pro T3 .96E lv eoo � Skagit County Area, Washington 78—Keystone loamy sand, 0 to 8 percent slopes Map Unit Setting • National map unit symbol: 2hx2 • Elevation: 0 to 300 feet • Mean annual precipitation: 23 inches • Mean annual air temperature: 50 degrees F • Frost -free period: 180 to 220 days • Farmland classification: Prime farmland if irrigated Map Unit Composition • Keystone and similar soils: 95 percent • Minor components: 5 percent • Estimates are based on observations, descriptions, and transects of the mapunit. Qescription of Keystone Setting • Landform: Moraines, kames • Parent material: Glacial outwash Typical profile Hi - 0 to 7 inches: loamy sand • H2 - 7 to 15 inches: loamy sand • H3 - 15 to 60 inches: sand Properties and qualities • Slope: 0 to 8 percent • Depth to restrictive feature: More than 80 inches • Drainage class: Excessively drained • Capacity of the most limiting layer to transmit water (Ksat): High to very high (5.95 to 19.98 in/hr) • Depth to water table: More than 80 inches • Frequency of flooding: None • Frequency of ponding: None • Available water capacity: Low (about 3.7 inches) Interpretive groups • Land capability classification (irrigated): 4e • Land capability classification (nonirrigated): 3s • Hydrologic Soil Group: A • Forage suitability group: Droughty Soils (G002XN402WA) • Other vegetative classification: Droughty Soils (G002XN402WA) • Hydric soil rating: No Minor Components Bow • Percent of map unit: S percent • Landform: Terraces • Other vegetative classification: Seasonally Wet Soils (G002XN202WA) • Hydric soil rating: Yes Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 3 — Model Soil Management Plan for BMP T5.13 An alternate document acceptable to the City of Anacortes is a Test Report provided by the Soils Supplier that identifies the soils to be used meet the specifications outlined under Minimum Requirement 5. The specifications are in both WSDOT and CSI Formats. For specifications, refer to the above referenced PDF. This submittal can be a deferred submittal since most projects are not sure who the supplier will be at the time of building permit application. For projects that trigger Minimum Requirements 1 through 5, the Test Report will be provided to the Building Department. Projects triggering Minimum Requirements 1 through 9, the Test Report will be provided to the Engineering Department, Version Date: October 7, 2019 Previous Version Date: February 20, 2019 DEFERRED SUBMITTAL: PROVIDE A TEST REPORT FROM SOILS SUPPLIER TO THE BUILDING DEto PROJECT INFORMATION "Model Soil Management Plan for BMP T5.13" age # of pages C'mmnlntp all infnrmatinn nn naae 1. anly cite addrecc and nermit number on additional nalzes. Site Address / Lot No.: -.— Permit Type: Permit Number: Permit Holder: Phone: Mailing Address: Contact Person: Phone: Plan Prepared Bye ATTACHMENTS REQUIRED (Check off required items that are attached to this plan) Site Plan showing, to scale: _Areas of undisturbed native vegetation (no amendment required) New planting beds and turf areas (amendment required) Type of soil improvement proposed for each area Soil test results (required if proposing custom amendment rates) Product test results for aroaosed amendments AREA # (should match Area # on Site Plan) PLANTING TYPE _Turf _Undisturbed native vegetation Planting Beds _ Other: SQUARE FOOTAGE OF THIS AREA: square feet SCARIFICATION _ inches (depth) of scarification needed to achieve finished total 12" loosened depth. Subsoil will be scarified PRE -APPROVED inches of compost or imported topsoil applied AMENDMENT METHOD: X 3_1 (conversion factor, inches to cubic yards) PRODUCT: Topsoil import = cu. yards per 1,000 sq. ft. Amend with compost X ,000s sq.ft. in this area Stockpile and amend _ = cubic yards of amendment -> -> -> QUANTITY: CU. YDS. cu. yds. stockpiled) (needed to cover this area to designated depth) CUSTOM AMENDMENT Attach test results and calculations. Topsoil import inches organic matter or topsoil import PRODUCT: Topsoil & compost lift X 3_1 Amend = cu. yards / 1,000 sq. ft. Stockpile and amend X ,000s sq.ft. in this area ( cu. yds. stockpiled) _ = cubic yards of amendment QUANTITY: CU. YDS. MULCH ,000 sq.ft. PRODUCT: X 6.2 (conversion, to give 2 inch mulch depth) = cubic yards of mulch --- - - -> QUANTITY: CU. YDS. Date: Inspector: Approved: Revisions Required: Date: Inspector: Approved: Revisions Required: Version Date: October 7, 2019 Previous Version Date: February 20, 2019 APPENDIX 4 — Determining Construction Site Sediment Damage Potential (Appendix 7 — NPDES Phase II Permit) Note: See attached. All projects within the City of Anacortes are required to complete that document under Appendix 4. Western Washington Phase H Stormwater° Permit i. APPENDIX 7 - Determining Construction Site Sediment Damage Potential The following rating system allows objective evaluation of a particular development site's potential to discharge sediment. Permittees may use the rating system below or develop alternative process designed to identify site -specific features which indicate that the site must be inspected prior to clearing and construction. Any alternative evaluation process must be documented and provide for equivalent environmental review. Step one is to determine if there is a sediment/erosion sensitive feature downstream of the development site. If there is such a site downstream complete step two, assessment of hydraulic nearness. If there is a sediment/erosion sensitive feature and it is hydraulically near the site then go to step three to determine the construction site sediment transport potential. Sediment/erosion sensitive features are areas subject to significant degradation due to the effect of sediment deposition or erosion. Special protection must be provided to protect them. Sediment/erosion sensitive features include but are not limited to: i. Salmonid bearing fresh water streams and their tributaries or freshwater streams that would be Salmonid bearing if not for anthropogenic barriers; ii. Lakes; iii. Category I, ll, and III wetlands; iv. Marine near -shore habitat; v. Sites containing contaminated soils where erosion could cause dispersal of contaminants; and vi. Steep slopes (25% or greater) associated with one of the above features. Identify any sediment/erosion sensitive features, and proceed to step two. If there are none the assessment is complete. Sites are hydraulically near a feature if the pollutant load and peak quantity of runoff from the site will not be naturally attenuated before entering the feature. The conditions that render a site hydraulically near to a feature include, but are not limited to, the following: i. The feature or a buffer to protect the feature is within 200 feet downstream of the site. ii. Runoff from the site is tight -lined to the feature or flows to the feature through a channel or ditch. August i, 2013, Moa'ifiecl ,1anuary 96, 2095 Appeerex`iK i- Detennining Sediment Damage Potential Page 1 of 3 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 A site is not hydraulically near a feature if one of the following takes place to provide attenuation before runoff from the site enters the feature: iv. Sheet flow through a vegetated area with dense ground cover v. Flow through a wetland not included as a sensitive feature vie Flow through a significant shallow or adverse slope, not in a conveyance channel, between the site and the sensitive feature. Identify any of the sediment/erosion sensitive features from step one that are hydraulically near the site, and proceed to step three. If none of the sediment/erosion sensitive features are hydraulically near the site, the assessment is complete. Using the worksheet below, determine the total points for each development site. Assign points based on the most critical condition that affects 10% or more of the site. If soil testing has been performed on site, the results should be used to determine the predominant soil type on the site. Otherwise, soil information should be obtained from the county soil survey to determine Hydrologic Soil Group (Table of Engineering Index Properties for step 1.D) and Erosion Potential (Table of Water Features for step 1.E) When using the county soil survey, the dominant soil type may be in question, particularly when the site falls on a boundary between two soil types or when one of two soil types may be present on a site. In this case, the soil type resulting in the most points on the rating system will be assumed unless site soil tests indicate that another soil type dominates the site. Use the point score from Step 3 to determine whether the development site has a high potential for sediment transport off of the site. Total Score Transport Rating <100 Low ❑ 100 High A high transport rating indicates a higher risk that the site will generate sediment contaminated runoff. Construction Site Sediment Transport Potential Worksheet A. Existing slope of site (average, weighted by aerial extent): PoMM ints 2% or less .. 0 >2-5%.............................................................................................. 5 >5-10%..........................................................................................15 >10-15%........................................................................................30 >15%.............................................................................................50 B. Site Area to be cleared and/or graded: <5,000 sq. ft...................................................................................... 0 5,000 sq. ft. — 1 acre....................................................................... 30 > 1 acres.......................................................................................... 50 C. Quantity of cut and/or fill on site <500 cubic yards............................................................................... 0 500 — 5,000 cubic yards..................................................................... 5 >51000 — 10,000 cubic yards.......................................................... 10 >103000 — 20,000 cubic yards ........................................................ 25 >20,000 cubic yards....................................................................... 40 I Runoff potential of predominant soils (Natural Resources Conservation Service): Hydrologic E. Erosion Potential of predominant soils (Unified Classification System): GW, GP, SW, SPsoils............................................................................................. 0 Dual classifications (GW-GM, GP -GM, GA -GC, GP -GC, SW-SM, SW -SC, SP-SM, SIP -SC) ........................... 10 GM, GC, SM, SC soils.................................................................... 20 ML, CL, MH, CH soils. I I I I I I I I I I I I 1 4 1 1 1 1 1 1 K I I I I I I I I I I I I I I I I I I K I I I I I I 1 "1 1 1 1 1 1 1 1 1 40 F. Surface or Groundwater entering site identified and interceptedl: Yes. . 4 9 k a 0 * * a a a 0 m 0 a * a 0 9 % d a a 9 * 0 0 a m a 9 0 s a 4 0 0 * W * 0 P * g W 0 P 0 , 0 , , 4 . . . . . . . . . . . . . . . . . . . 0 No, I I I I I I I I I I I I I I I I I I I I I I I I I I I I I K I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 1 25 G. Depth of cut or height of fill >10 feet: Yes.................................................................................................. 25 No., We Fosaalwl Is 11 P'lol"PoVIVIIIII I................... 0 H. Clearinq and grading will occur in the wet season (October 1 — May 1): Yes 50 No. . a 9 5 0 a 0 1 a a 0 1 B a a I a I a 0 ff 9 0 0 F a 0 0 0 0 0 F 0 a 9 w 0 0 0 0 5 a 5 a 0 w 9 0 0 0 0 m 1 0 V 0 a 9 w a a a a a a a 5 V w V T 1 0 0 4 W P W P a 0 . 0 P F F P , a P W P , P 4 , W W , A 0 4 50 TOTAL POINTS.............................................................................................45 1 If no surface or groundwater enters site, give 0 points. APPENDIX 5 — Site Plan with all applicable information (Minimum Size 11x17 al. a legible scale) SSCO • � SS A-0B5 STUB L,J JI H 1 A BMP C240 lE1P. BW C154 (f0 SEDD4ENi TRAP COl*XTE �\ 6' X 9' SURFACE AREA ABOVE DVElMW a SEE DEAL Li LOT A ti z L _ 7,150 SF U V_ SITE I 40M SaintMI Q b, LOT_ 7,150 Marys Drive ZS PAST-CONSTRUCTIM I HOIM = 2,� SF I HOUSE a SEEL QUALITY AND SF , PATIO = 294 SF I 2/ � DEPTH ON ALL BMP C105/CI07 PORCH w 144 SF cn DISTURBED SOILS CQ:STRUGTHN ti DRIVEWAY/SIDEWALK =1 SF u CRUSHED ROCK BASE PERVIOUS = 3� SF31 3 SF (DRIVEWAY o IJ SIDEWALK � -- BMP C154 _I ?30 MPTC2F333 I 509 SF 4 t0PPERFQHATEB BMP C2.40 TEMP. CONCRETE STUB OUT EACH SEDIMENT TRAP WASH -OUTS 00 17 E— TOP.w — — MOUSE 0' X B SURFACE AREA SEE DETAIL ABOVE OVERFLOW — I SEE MAIL I ` `LOT B EX. CB TYPEI I RIM = 231.20' BMP C123 I 6,798 SF I DRIVEWAY I.E. = 226.2' __ L UPLAND AREA I Ss .WS K BW cI05I io7 0 STOCKcl PILE �TM I � 10,502 SF TOTAL 1 CONSTRUrnDN COVER WITH .STRAW OR I k`!TRAPdE U VISQIEEN BW C233 r v'`, ry CRUSHED FM BASE m SILT FENCE 4010 Saint Mary's Drive PATIO HOUSE 401 94 2,375 SF = J I W ` m SSMH A-039 CD v I II INV.-4.9' _ T5A3 M POST-CWSTRUCTION 3 I SOIL QUALITY AND y DEPTH ON ALL DISTURBED SODS j N BMP C103 ` y I HIGH VISIBILITY \1, £DG L ,o FENCE 40.01l S 80*24136' E 92.49' I GRAPHIC SCALE 15 0 15 30 60 ( IN FEET ) 1 inch = 30 ft. HERRIGSTAD ENGINEERING & 5' URTTEYING E C S z NO Too Ifir Of pd ONE or or ..1.' 1 r rew I or or or ra &INNI or o. No LIN or to1. Err a ratio 11 IN TI WK NOW y wYNo f�o II or r to k g Ali _ wo -�`o �r - - -i- I' Lo r \ ' - i.' i + _ t .� ILL a• ' L i. .. - �,, "' r et;. ; >'t •y' { 4 ' .` .` ILL ;4r . Al t� Yj �Sn , -1 • ' . 2 `y r �; it - mC tIII 1 .N1 . LOW Lot `.i AI LA I t, ixio tDD�; i �'" ' ; to;Arol"_ . '`"' APPENDIX 7 — Drainage BMP Facility Maintenance Covenant Note: To be recorded prior to: 1) Temporary Certificate of Occupancy; 2) Final Certificate of Occupancy, and or; 3) Final Acceptance of the project. This is Covenant is required for any Permanent Stormwater Facy constructed on a project site. The applicant should work with the the City of Anacortes Engineering Department on formalizing the document for recording. There are no maintenance covenants for Perforated Stub Outs.