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Home My WebLink AboutGVR-2026-0003 - CLEAR & GRADE (GRADING & VEGETATION REMOVAL)PARCEL: P58060 LEGAL DESCRIPTION: LOTS 11 AND 12 AND THE SOUTH 30 FEET OF LOTS 8, 9 AND 10, BLOCK 1, NELSON'S ADDITION TO ANACORTES, AS PER PLAT RECORDED IN VOLUME 2 OF PLATS, PAGE 102, RECORDS OF SKAGIT COUNTY, WASHINGTON. APPLICANT: Blais, Jimmy 5050 1st Ave S Suite 102 Seattle, WA 98134 2062555153 OWNER: MJB PROPERTIES LLC UNKNOWN 9125 10TH AVE S SEATTLE, WA 98108 FEES:Paid Due Monitoring Clear and Grade Fee $201.40 $0.00 Storm Water Review Sq Ft $35.52 $0.00 Grading Permit Fee $252.50 $0.00 SEPA Threshold Determination Fee $480.00 $0.00 Grading Plan Review Fee $49.25 $0.00 Third Party Stormwater Review Fees - 1st Review $1,181.00 $0.00 $0.00Totals : REQUIRED INSPECTIONS Initial BMP's. This stormwater inspection must be completed prior to any other inspections. Stormwater Final Public Works Final CITY STAFF:PCED Department, Staff 904 6th Street Anacortes, WA 98221 3605888119 CONSTRUCTION CONTRACTOR:GARY MERLINO CONST CO INC 9125 10TH AVE S SEATTLE, WA 98108 2067629125 License: GARYMCC150MW Expires: 02/14/2027 $2,199.67 GVR-2026-0003 CLEAR AND GRADE ISSUED: EXPIRES: 08/18/2026 08/18/2028 PROJECT NAME: MJB BATHROOM GRADE AND FILL SITE ADDRESS: 2111 R AVE ANACORTES Page 1 of 2Printed by : Jennifer Watson on: 09/01/2026 03:28 PM City of Anacortes, WA 904 6th Street Anacortes, WA 98221 (360) 293-1901 http://cityofanacortes.org/ Please request inspections online through the permit portal. If that is not possible please call (360) 293-1901 for Building or Planning inspections. For Public Works inspections, please call (360) 293-1938. * This permit is issued consistent with the Mitigated Determination of NonSignificance (MDNS) prepared under the State Environmental Policy Act (SEPA), SEPA File No. 202603277. All mitigation measures and conditions outlined in the original MDNS (202101192) are incorporated by reference as enforceable conditions of this permit. Construction activities authorized by this permit shall comply fully with all such mitigation requirements. Non-compliance with any MDNS condition may result in suspension, modification, or revocation of this permit. * Compliance with City Ordinance 4087. PUBLIC ACCESS OF THE RESTROOMS AND PARKING LOT SHALL REMAIN UNINTERRUPTED UNTIL SEPTEMBER 3, 2026. CONDITIONS Page 2 of 2Printed by : Jennifer Watson on: 09/01/2026 03:28 PM City of Anacortes, WA CLEAR AND GRADE GVR-2026-0003 REVISED SEPA CHECKLIST ACCEPTED 08/04/2026 20) P58060 - MJB PROPERTIES, LLC and parking lot ^ The 2025 Anacortes Comprehensive Plan designation of the site is "Marine Mixed Use" The current Anacortes shoreline environment designation is "Urban" & "Aquatic" The City of Anacortes classifies the shoreline as a Fish and Wildlife Habitat Conservation Area, Tsunami Hazard Area, and Liquefaction Susceptibility Area. 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com MJB BATHROOM MJB PROPERTIES SECTION 19, TOWNSHIP 35 NORTH, RANGE 02 EAST, WM ANACORTES, WA JUNE 2026 DATUM HORIZONTAL DATUM: NAD 83/91 VERTICAL DATUM: NAVD88 6/9/2026 CITY OF ANACORTES PLANNING AND BUILDING DEPT: APPROVED PLANS REVIEWED FOR CODE COMPLIANCE PERMIT#___________________________ ADDRESS___________________________ SIGNATURE DATE PLANNING APPROVED BUILDING APPROVED ENGINEERING ACCEPTED STORMWATER ACCEPTED Stamp not valid unless signed GVR-2026-0003 2111 R Avenue 08/03/2026 PURSUANT TO THE TERMS OF ORDINANCE 4087, PUBLIC ACCESS TO THE ON-SITE RESTROOM AND PARKING LOT SHALL REMAIN UNINTERRUPTED UNTIL SEPTEMBER 3, 2026. THE DEMOLITION OF THE SUBJECT PARKING LOT AND PEDESTRIAN ACCESS, AS SHOWN IN THIS APPROVED PERMIT, SHALL NOT COMMENCE PRIOR TO SEPTEMBER 3, 2026. REVISED SEPA MDNS ISSUED 08/04/2026 (ECOLOGY RECORD #202603277). THE REVISED MDNS DID NOT CHANGE THE ORIGINAL CONDITIONS OF APPROVAL FOR MITIGATING ENVIRONMENTAL IMPACTS THAT WAS ISSUED IN 2021 UNDER THE ORIGINAL THRESHOLD DETERMINATION (SEPA ECOLOGY RECORD 202101192). THIS PERMIT IS REQUIRED TO COMPLY WITH ALL CONDITIONS OF SEPA RECORD 202101192. 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com 6/9/2026 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com · · 6/9/2026 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com 6/9/2026 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com 6/9/2026 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com 6/9/2026 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com 6/9/2026 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com 6/9/2026 EXISTING AND PROPOSED CHAIN-LINK FENCING LOCATED WITHIN TEN FEET (10') OF A STREET RIGHT-OF-WAY IS ONLY PERMITTED AS TEMPORARY CONSTRUCTION FENCING. A PERMANENT CHAIN-LINK FENCE LOCATED WITHIN TEN FEET (10') OF A STREET RIGHT-OF-WAY IS PROHIBITED. (AMC 19.66.070(A)(1)) Bathroom Rough Grading City of Anacortes, WA Stormwater Site Report June 2026 Bathroom Rough Grading –MJB Properties i Stormwater Site Report June 2026 Prepared for: MJB Properties 5050 First Avenue South, Suite 102 Seattle, WA 98134 City of Anacortes Public Works Department 2201 37th Street Anacortes, WA 98221 Prepared by: KPFF Consulting Engineers 1601 Fifth Avenue, Suite 1600 Seattle, WA 98101 Phone: (206) 622-5822 KPFF Project No. 1900301 Project Engineer: Kristin Montgomery, PE Project Manager: Kyle Carrick, PE Designer of Record: Joe Eberhardt, PE, Principal Associated Permits: Clearing and Grading Permit 6/9/2026 KPFF Consulting Engineers ii Bathroom Rough Grading–MJB Properties iii Table of Contents Tab 1 -- (Minimum Requirement #1 -- Preparation of Stormwater Site Plans) ..................................................... 7 Tab 2 -- (Minimum Requirement #2 -- Construction Stormwater Pollution Prevention (SWPP))........................ 11 Tab 3 -- (Minimum Requirement #3 -- Source Control of Pollution) .................................................................... 31 Tab 4 -- (Minimum Requirement #4 -- Preservation of Natural Drainage Systems and Outfalls) ....................... 32 Tab 5 -- (Minimum Requirement #5 -- On-site Stormwater Management) ......................................................... 33 Tab 6 – (Minumum Requirement #6 – Runoff Treatment) .................................................................................. 35 Tab 7 – (Minumum Requirement #7 – Flow Control) .......................................................................................... 36 Tab 8 – (Minumum Requirement #8 – Wetland Protection) ................................................................................ 37 Tab 9 – (Minumum Requirement #9 – Operation and Maintenance) .................................................................. 38 Figures Figure I-2.4.1: Flow Chart for Determining Requirements for New Development ............................................... 4 Figure I-2.4.2: Flow Chart for Determining Requirements for Redevelopment .................................................... 5 Figure I-2.5.1: Flow Chart for Determining LID MR #5 Requirements ................................................................. 6 Appendices Appendix 1 – Survey Appendix 2 – Geotechnical Reports Appendix 3 – Model Soil Management Plan for BMP T5.13 Appendix 4 – Determining Construction Site Sediment Damage Potential Appendix 5 – Site Plan Appendix 6 – Site Photos Appendix 7 – Drainage BMP Facility Maintenance Covenant Appendix 8 – Operation and Maintenance Manual Appendix 9 – Stormwater Pollution Prevention Plan (SWPPP) KPFF Consulting Engineers iv This page intentionally left blank. Version Date: 07/26/24 Page 1 Storm Water Drainage Report Minimum Requirement 1 through 9 ENGINEERING DEPARTMENT 904 6th Street Anacortes, WA 98221 www.anacorteswa.gov Official Use Only: (Information to Inspectors) Required Storm Water Facility and other related requirements: ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ Project Address: 1701 Q Avenue, Anacortes, WA Submittal Date: __________________ Parcel Number: P58060,P58059, P78000 Revision Number: Permit Number: ________________ Reviewer: Acceptance Date (COA):____________ 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. o APPENDIX 8 – Maintenance and Operations Manual Stormwater Management Requirements: o Refer to the 2019 Department of Ecology Manual - 2024 manual will be adopted soon 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: 07/26/24 Page 2 Project Description and Summary: Summary Table Existing Proposed Development Type Marine Mixed Use New Marine Mixed- Use Number of Lots 3 parcels 3 parcels Lot Acreage in SF Acreage = 2.03 acres (~81,491 sf) Acreage = 2.03 acres (~81,491 sf) Soil Type(s) Crushed rock top course, construction rubble and debris, and moderately organic silt/clay Imported structural fill Site Sediment Transport Score (High\Low) Low High (See Appendix 4) Depth to Ground Water Table (Feet and Inches) (See completed Soils Analysis (Volume 1, Chapter 3.1.1) 2.75-3.25 feet N/A Infiltration Rate during Rainy Season (Inch\Per Hour) Not suitable N/A Impervious Surface (on-site) ~6,960 sf (0.160 acres) ~285 sf (0.007 acres) Impervious Surface (off-site) 0 sf 0 sf New and Replaced Hard Surface Total (SF) N/A 0 SF Lot Coverage (Percentage) 8.5% 0.3% BMP (Required Minimum Requirement 5) None BMP T5.13 Post- Construction Soil Quality and Depth Water Quality Method (Minimum Requirement 6) None Not Required Water Quantity Method (Minimum Requirement 7) None Not Required 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 Phasing\Sequence ) The existing site has minimal vegetation, one building, asphalt pavement, utilities (gas, storm, water, electrical, sewer), and concrete sidewalk. Generally, the site slopes south to north with approximately 11-feet of elevation drop. Stormwater runoff from the existing site is collected by catch basins and conveyed to existing stormwater outfalls to Fidalgo Bay. Stormwater from the City of Anacortes (City) right-of-way (ROW) to the west (R/Q Avenue) is collected at the 20th Street intersection and conveyed east to a 12” stormwater outfall on-site under easement. The last known permit for this area was a 2021 clearing and grading permit and shoreline substantial development permit. The surrounding properties were rough graded and roadway infrastructure installed. 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 rough graded to generally slope to the north towards toward a interceptor swales along the sides of 20th Street. The interceptor swales will will tie in to existing swales routed to catch basins. Runoff will be collected by the existing drainage structures and conveyed to the existing stormwater drainage system and discharged to Fidalgo Bay through the existing 36” stormwater outfall. Version Date: 07/26/24 Page 3 (2007 Storm Comp Plan – City website\publicworks\engineering\comprehensive plans): What Drainage Basin are you in? Fidalgo Drainage Basin Identify any downstream drainage issues (Storm Comp Plan: NA_____ If so, describe: NA Complete the Applicability Requirements – Flow Chart (Figure I-2.4.1 Attached, Figure I-2.4.2 Attached and Figure I-2.5.1 Attached) - Highlight the path and attach Version Date: 07/26/24 Page 4 Version Date: 07/26/24 Page 5 Version Date: 07/26/24 Page 6 Version Date: 07/26/24 Page 7 TAB 1 (MINIMUM REQUIREMENT #1) • 1-3.4.1 Minimum Requirement #1 – Prepare a Stormwater Site Plan Note: The level of detail needed for each step depends upon the project size. Provide a narrative description of each step. Step 1 – Analyze Existing Site Conditions to Determine LID Feasibility The existing site analysis is intended to determine the pre-development conditions on the site in addition to determining the appropriateness for use of Low Impact Development (LID) techniques. Site conditions as identified in this step will determine the feasibility of the overall stormwater design including use of LID techniques. The development context shall be established by an existing site analysis consistent with the requirements detailed in this Step. The initial inventory and analysis process will provide baseline information necessary to design strategies that utilize areas most appropriate to evaporate, transpire, and infiltrate stormwater, and achieve the goal of mimicking the pre-development natural hydrologic conditions on the site. The existing site analysis shall include, at a minimum, the following information: 1. A survey prepared by a registered land surveyor, civil engineer, or other qualified professional showing: (See this section for additional items to include) 2. A soils report prepared by a professional soil scientist certified by the Soil Science Society of America (or an equivalent national program), or by other suitably trained persons working under the supervision of a professional engineer, geologist, hydrogeologist, or engineering geologist registered in the State of Washington. The project is not proposing any new or replaced hard surfaces subject to LID facilities. Existing site conditions are documented in the following: Record of Survey performed – Appendix 1___________________________________________ Preliminary Infiltration Report by Coastal Geologic Services (November 27, 2019) – Appendix 2 Geotechnical Report – Appendix 2_________________________________________________ Site pictures – Appendix 6_______________________________________________________ Step 2 - Prepare Preliminary Development Layout Based upon the existing site analysis results, locate the buildings, roads, parking lots, landscaping features, LID BMPs, and preliminary location of Runoff Treatment and Flow Control BMPs for the proposed development. Consider the following points when laying out the site: • Fit development to the terrain to minimize land disturbance; confine construction activities to the least area necessary, and away from critical areas. • Preserve areas with natural vegetation (especially forested areas) as much as possible. • On sites with a mix of soil types, locate impervious areas over less permeable soil (e.g., till), try to restrict development over more porous soils or take advantage of them by locating bioretention, rain gardens and/or permeable pavement over them. • Cluster buildings together. • Minimize impervious areas. • Maintain and utilize the natural drainage patterns. Version Date: 07/26/24 Page 8 The project is not proposing any new or replaced hard surfaces subject to LID facilities. Cleared areas will be converted to lawn and use Compost Amended Soil per BMP T5.13. See Site Plan in Appendix 5.___________________________________________________________ Step 3 - Perform Off-site Analysis City of Anacortes requires an off-site analysis for projects that add 5,000 SF or more of new hard surfaces, or convert ¾ acres of vegetation to lawn or landscape areas, or convert 2.5 acres of forested area to pasture. Off-site analysis extends to ¼ mile downstream of the project site. Off-site analysis is not required for this project because it does not meet the above requirements. Step 4 – Determine and Read the Applicable Minimum Requirements (Place at the front end of the document before MR#1) I-3.3 Applicability of the Minimum Requirements establishes project thresholds for the application of Minimum Requirements to new development and redevelopment projects. Figure I-3.1: Flow Chart for Determining Requirements for New Development (Included in the report) and Figure I-3.2: Flow Chart for Determining Requirements for Redevelopment (Included in the report) provide the same thresholds in a flow chart format. Based on the preliminary layout, determine whether Minimum Requirements #1 and #2 only apply to the project, or #1 through #5 only apply to the project, or #1 through #9 apply. The project is subject to Minimum Requirements #1-5 for new and replaced hard surfaces and the land disturbed. Step 5 - Prepare a Permanent Stormwater Control Plan (Place in Appendix 5 of this report) (Due to the extent of required information for this section, refer to this section of the Ecology Manual for requirements.) The Site Plan is included in Appendix 5._________________________________________________ Step 6 - Prepare a Construction Stormwater Pollution Prevention Plan (Place in MR#2 – 13 Elements) The Construction SWPPP for projects adding or replacing 2,000 square feet of hard surface or more, or clearing 7,000 square feet or more, must contain sufficient information to satisfy the local government Plan Approval Authority that the potential pollution problems have been adequately addressed for the proposed project. Local governments may adopt a standard SWPPP format for use by projects less than 1 acre. An adequate Construction SWPPP includes a narrative and drawings. The narrative is a written statement to explain and justify the pollution prevention decisions made for a particular project. The narrative contains concise information concerning existing site conditions, construction schedules, and other pertinent items that are not contained on the drawings. The drawings and notes describe where and when the various BMPs should be installed, the performance the BMPs are expected to achieve, and actions to be taken if the performance goals are not achieved. See II-2.4 Preparing Construction SWPPPs for details about what to include in the project's Construction SWPPP. Version Date: 07/26/24 Page 9 This project will use the active SWPPP for the site as a continuation of the rough grading work. See approved SWPPP in Appendix 9._______________________________________________________ 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: A. Project Overview (Front End) B. Existing Conditions Summary (Front End) C. Off-site Analysis Report (Minimum Requirement 1, Step 3) D. Permanent Stormwater Control Plan (Appendix 5) E. Construction Stormwater Pollution Prevention Plan (Minimum Requirement 2) F. Special Reports and Studies (Survey – Appendix 1, Geotechnical – Appendix 2, all others placed after Appendix 8) G. Other Permits, if applicable H. Operation and Maintenance Manual (Appendix 8) I. Declaration of Covenant for Privately Maintained Flow Control and Treatment Facilities. (See attached Drainage BMP Maintenance Covenant BMP Agreement) (Appendix 7) J. Declaration of Covenant for Privately Maintained On-site Stormwater BMP’s (See attached Drainage BMP Maintenance Covenant BMP Agreement) (Appendix 7) K. Bond Quantities Worksheet, if applicable This report encompasses all applicable elements to the project. __________________________________________________________________________________ ________________________________________________________________________ Step 8 - Check Compliance with all Applicable Minimum Requirements Before Submitting this report, a Stormwater Site Plan as designed and implemented should specifically fulfill all Minimum Requirements applicable to the project. The Stormwater Site Plan should be reviewed to check that these requirements are satisfied. Note: The report will be returned if determined incomplete. Project fulfills all Minimum Requirements applicable to the project. __________________________________________________________________________________ ________________________________________________________________________ Version Date: 07/26/24 Page 10 Version Date: 07/26/24 Page 11 TAB 2 (MINIMUM REQUIREMENT #2) 1-3.4.2 Minimum Requirement #2 – Construction Stormwater Pollution Prevention Plan (SWPP) All new development and redevelopment projects are responsible for preventing erosion and discharge of sediment and other pollutants into receiving waters. Projects which result in 2,000 square feet or more of new plus replaced hard surface area, or which disturb 7,000 square feet or more of land must prepare a Construction Stormwater Pollution Prevention Plan (SWPPP) as part of the Stormwater Site Plan (see MR1: Preparation of Stormwater Site Plans). Projects below those thresholds (listed above) are not required to prepare a Construction SWPPP, but must consider all of the Construction SWPPP Elements (listed below) and develop controls for all Construction SWPPP Elements that pertain to the project site. General Requirements: The Construction SWPPP shall include a narrative and drawings. All BMPs shall be clearly referenced in the narrative and marked on the drawings. The Construction SWPPP narrative shall include documentation to explain and justify the pollution prevention decisions made for the project. Each of the 13 Construction SWPPP Elements (listed below) must be considered and included in the Construction SWPPP unless site conditions render the Element unnecessary and the exemption from that Element is clearly justified in the narrative of the SWPPP. Clearing and grading activities for developments shall be permitted only if conducted pursuant to an approved site development plan (e.g., subdivision approval) that establishes permitted areas of clearing, grading, cutting, and filling. These permitted clearing and grading areas and any other areas required to preserve critical or sensitive areas, buffers, native growth protection easements, or tree retention areas, shall be delineated on the site plans and the development site. The Construction SWPPP shall be implemented beginning with initial land disturbance and until final stabilization. Sediment and Erosion control BMPs shall be consistent with the BMPs contained in II-3 Construction Stormwater BMPs. Seasonal Work Limitations: From October 1 through April 30, clearing, grading, and other soil disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority that silt-laden runoff will be prevented from leaving the site through a combination of the following: 1. Site conditions including existing vegetative coverage, slope, soil type and proximity to receiving waters; and 2. Limitations on activities and the extent of disturbed areas; and 3. Proposed erosion and sediment control measures. 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, and 3. Activities where there is one hundred percent infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. Version Date: 07/26/24 Page 12 Version Date: 07/26/24 Page 13 Version Date: 07/26/24 Page 14 Version Date: 07/26/24 Page 15 Version Date: 07/26/24 Page 16 Version Date: 07/26/24 Page 17 13 Elements of SWPPP (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 2019 Stormwater Management Manual for Western Washington (SWMMWW). 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: MJB Properties, Inc. Site Address: Q Avenue, Anacortes, WA Prepared By: KPFF Consulting Engineers 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. Suggested BMPs for Element 1: • BMP C101: Preserving Natural Vegetation • BMP C102: Buffer Zones • BMP C103: High-Visibility Fence • BMP C233: Silt Fence How did you comply with this section? There is minimal topsoil and natural vegetation to preserve. BMP C103 High Visibility Fence may be provided to contain the site. 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. X X X X X Version Date: 07/26/24 Page 18 € 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. Additional Guidance for Element 2 Minimize construction site access points along linear projects, such as roadways. Street washing may require local jurisdiction approval. Suggested BMPs for Element 2: • BMP C105: Stabilized Construction Access • BMP C106: Wheel Wash • BMP C107: Construction Road / Parking Area Stabilization How did you comply with this section? BMP C105 Stabilized Construction Access will be installed from 20th Street. ELEMENT 3: Control Flow 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. X X X Version Date: 07/26/24 Page 19 BMP C207 Check Dams will be used to slow velocity in interceptor swales. The project is not proposing permanent detention or infiltration facilities. Version Date: 07/26/24 Page 20 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. X X X X X Version Date: 07/26/24 Page 21 BMP C233 Silt Fence BMP C105 Stabilized Construction Entrance BMP C220 Storm Drain Inlet Protection 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 € 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. € X X X X X X X X Version Date: 07/26/24 Page 22 BMP C121 Mulching BMP C123 Plastic Covering BMP C140 Dust Control 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 slope drains or protected channels to prevent erosion. Temporary pipe slope drains must be sized to convey the flow rate calculated by the one fo the following methods: • Single Event Hydrograph Method: The peak volumetric flow rate calculated using a 10-minute time step from a Type 1A, 10-year, 24-hour frequency storm, or; • Continuous Simulation Method: The 10-year peak flow rate, as determined by an approved continuous runoff model with a 15-minute time step. 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. X X Version Date: 07/26/24 Page 23 € 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. Site is relatively flat and does not have any steep slopes. BMP C200 Interceptor Dike and Swale and BMP C207 Check Dams will be used at the low end of the site. 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). Additional Guidance for Element 7 • 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 waters of the State. • Inlets should be inspected weekly at a minimum and daily during storm events. X X X X Version Date: 07/26/24 Page 24 BMP C220 Storm Drain Inlet Protection will be installed in all downstream structures. ELEMENT 8: Stabilize Channels and Outlets € Design, construct, and stabilize all on-site conveyance channels to prevent erosion from the flow rate calcultated by one the following methods: • Single Event Hydrograph Method: The peak volumetric flow rate calculated using a 10-minute time step from a Type 1A, 10-year, 24-hour frequency storm, or; • Continuous Simulation Method: The 10-year peak flow rate, as determined by an approved continuous runoff model with a 15-minute time step. 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. € Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent streambanks, slopes, and downstream reaches at the outlets of all conveyance systems. Additional Guidance for Element 8 The best method for stabilizing channels is to completely line the channel with BMP C122: Nets and Blankets first, then add BMP C207: Check Dams as necessary to function as an anchor and to slow the flow of water. BMP C207 Check Dams will be used to slow runoff within interceptor swales. X X Version Date: 07/26/24 Page 25 ELEMENT 9: Control Pollutants Design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants. The project proponent must: € 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, or to the sanitary sewer, with local sewer district approval. € 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. € Uncontaminated water from water-only based shaft drilling for construction of building, road, and bridge foundations may be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters. Prior to infiltration, water from water-only based shaft drilling that comes into contact with curing concrete must be neutralized until pH is in the range of 6.5 to 8.5 (su) Additional Guidance for Element 9 • Wheel wash and/or tire bath wastewater can be combined with wastewater from concrete washout • areas if the wastewaters will be properly disposed of at an offsite location or treatment facility. • Do not use upland land applications for discharging wastewater from concrete washout areas. • 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. X X X X X X X Version Date: 07/26/24 Page 26 All paints and solvents will be stored under cover out of the weather elements. Contractor to have a spill prevention kit at all times on-site. BMP C152 Sawcutting and Surfacing Pollution Prevention to be used for concrete removal. 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 BMP C240: Sediment Trap or BMP C241: Sediment Pond (Temporary). € Discharge foundation, vault, and trench dewatering water, which have similar characteristics to stormwater runoff at the site, into a controlled conveyance system before discharge to Discharge clean, non-turbid dewatering water, such as well-point ground water, to systems tributary to, or directly into surface waters of the State, as specified in Element 8: Stabilize Channels and Outlets, provided the dewatering flow does not cause erosion or flooding of receiving waters. Do not route clean dewatering water through stormwater sediment BMPs. 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. € Handle highly turbid or otherwise contaminated dewatering separately from stormwater. € Other dewatering treatment or disposal options may include: 1. Infiltration 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. Version Date: 07/26/24 Page 27 Groundwater is not aniticpated to be encountered during construction. 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. Additional Guidance for Element 11 • 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 documents. • Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. Contractor to maintain a Certified Erosion and Sediment Control Lead and will be responsible for maintaining and removing all BMPs. BMPs will be inspected daily, as necessary per the 2019 DOE SWMMWW Appendix II-A. Weekly erosion and sedimentation reports are to be sent to the City. ELEMENT 12: Manage the Project € 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. € Inspect, maintain and repair all BMPs as needed to assure continued performance of their intended function. Projects regulated under the Construction Stormwater General Permit (CSWGP) must conduct site inspections and monitoring in accordance with Special Condition S4 of the CSWGP. € Maintain, update, and implement the SWPPP. Projects that disturb one or more acres must have site inspections conducted by a Certified Erosion and Sediment Control Lead (CESCL). Project sites disturbing less than one acre may have a CESCL or a person without CESCL certification conduct inspections. By the initiation of construction, the Construction SWPPP must identify the CESCL or inspector, who must be present on site or on-call at all times. X X X X X X Version Date: 07/26/24 Page 28 Additional Guidance for Element 12 The project manager must ensure that the project is built in such a way to comply with all Construction SWPPP Elements, as detailed in this section. Considerations for the project manager include, but are not limited to: • construction phasing • seasonal work limitations • coordination with utilities and other contractors • inspection • monitoring • maintaining an updated construction SWPPP Phasing of Construction Phase development projects where feasible in order to prevent soil erosion and transporting of sediment from the site during construction. Revegetate exposed areas and maintain that vegetation as an integral part of the clearing activities for any phase. Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g., subdivision approval) that establishes permitted areas of clearing, grading, cutting, and filling. Minimize removing trees and disturbing or compacting native soils when establishing permitted clearing and grading areas. Show on the site plans and the development site permitted clearing and grading areas and any other areas required to preserve critical or sensitive areas, buffers, native growth protection easements, or tree retention areas as may be required by local jurisdictions. Inspection All BMPs must be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections must be conducted by a person knowledgeable in the principles and practices of erosion and sediment control. The person must have the skills to 1) assess the site conditions and construction activities that could impact the quality of stormwater, and 2) assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. For construction sites one acre or larger that discharge stormwater to surface waters of the state, a CESCL must be identified in the construction SWPPP; this person must be on-site or on-call at all times. Certification must be obtained through an approved training program that meets the erosion and sediment control training standards established by Ecology. See BMP C160: Certified Erosion and Sediment Control Lead. Appropriate BMPs or design changes shall be implemented as soon as possible whenever inspection and/or monitoring reveals that the BMPs identified in the Construction SWPPP are inadequate, due to the actual discharge of /or potential to discharge a significant amount of any pollutant. The CESCL or inspector must examine stormwater visually for the presence of suspended sediment, turbidity, discoloration, and oil sheen. They must evaluate the effectiveness of BMPs and determine if it is necessary to install, maintain, or repair BMPs to improve the quality of stormwater discharges. Based on the results of the inspection, construction site operators must correct the problems identified by: • Reviewing the Construction SWPPP for compliance with the 13 elements and making appropriate revisions within 7 days of the inspection. Version Date: 07/26/24 Page 29 • Immediately beginning the process of fully implementing and maintaining appropriate source control and/or treatment BMPs as soon as possible, addressing the problems no later than within 10 days of the inspection. If installation of necessary treatment BMPs is not feasible within 10 days, the construction site operator may request an extension within the initial 10-day response period. • Documenting BMP implementation and maintenance in the site log book (applies only to sites that have coverage under the Construction Stormwater General Permit). The CESCL or inspector must inspect all areas disturbed by construction activities, all BMPs, and all stormwater discharge points at least once every calendar week and within 24 hours of any discharge from the site. (For purposes of this condition, individual discharge events that last more than one day do not require daily inspections. For example, if a stormwater pond discharges continuously over the course of a week, only one inspection is required that week.) The CESCL or inspector may reduce the inspection frequency for temporary stabilized, inactive sites to once every calendar month Maintaining an Updated Construction SWPPP Retain the Construction SWPPP on-site or within reasonable access to the site. Modify the Construction SWPPP whenever there is a change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the state. The Construction SWPPP must be modified if, during inspections or investigations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the Construction SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. Modify the Construction SWPPP as necessary to include additional or modified BMPs designed to correct problems identified. Complete revisions to the Construction SWPPP within seven (7) days following the inspection. Suggested BMPs for Element 12 • BMP C150: Materials on Hand • BMP C160: Certified Erosion and Sediment Control Lead • BMP C162: Scheduling How did you comply with this section? Contractor will manage the site with a CESCL and phasing as appropriate. ELEMENT 13: Protect Low Impact Development BMPS The primary purpose of On-Site Stormwater Management is to reduce the disruption of the natural site hydrology through infiltration. BMPs used to meet I-3.4.5 MR5: On-Site Stormwater Management (often called LID BMPs) are permanent facilities. € Protect all LID BMPs (including, but not limited to BMP T7.30: Bioretention, BMP T5.14: Rain Gardens, and BMP T5.15: Permeable Pavements) from sedimentation through installation and maintenance of erosion and sediment control BMPs on portions of the site that drain into the LID BMPs. Restore the BMPs to their fully functioning condition if they accumulate sediment during construction. Restoring the BMP must include removal of sediment and any sediment-laden Bioretention/Rain Garden soils, and replacing the removed soils with soils meeting the design specification. € Maintain the infiltration capabilities of LID BMPs by protecting against compaction by construction equipment and foot traffic. Protect completed lawn and landscaped areas from compaction due to construction equipment. Version Date: 07/26/24 Page 30 € Control erosion and avoid introducing sediment from surrounding land uses onto BMP T5.15: Permeable Pavements. Do not allow muddy construction equipment on the base material or pavement. € Permeable pavement fouled with sediments or no longer passing an initial infiltration test must be cleaned using procedures in accordance with this manual or the manufacturer’s procedures. € Keep all heavy equipment off existing soils under LID BMPs that have been excavated to final grade to retain the infiltration rate of the soils. Additional Guidance for Element 13 See Chapter 5: Precision Site Preparation, Construction & Inspection of LID Facilities in the LID Technical Guidance Manual for Puget Sound (Hinman and Wulkan, 2012) for more detail on protecting LID integrated management practices. Note that the LID Technical Guidance Manual for Puget Sound (Hinman and Wulkan, 2012) is for additional informational purposes only. You must follow the guidance within this manual if there are any discrepancies between this manual and the LID Technical Guidance Manual for Puget Sound (Hinman and Wulkan, 2012). Suggested BMPs for Element 13 • BMP C102: Buffer Zones • BMP C103: High-Visibility Fence • BMP C200: Interceptor Dike and Swale • BMP C201: Grass-Lined Channels • BMP C207: Check Dams • BMP C208: Triangular Silt Dike (TSD) • BMP C231: Brush Barrier • BMP C233: Silt Fence • BMP C234: Vegetated Strip How did you comply with this section? No LID BMPs are proposed at this time. ___________________________________________ _____________________ Applicant Signature Date Version Date: 07/26/24 Page 31 TAB 3 (MINIMUM REQUIREMENT #3) • 1-3.4.3 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. Supplemental Guidelines Source Control BMPs include Operational BMPs and Structural Source Control BMPs. See Volume IV for design details of these BMPs. For construction sites, see II-3.2 Construction Source Control BMPs. Structural Source Control BMPs should be identified in the stormwater site plan and should be shown on all applicable plans submitted for local government review and approval. An adopted and implemented Basin Plan (see Appendix I-B: Basin Plans) or Total Maximum Daily Load (see I-2.13 Total Maximum Daily Loads (TMDLs)) may be used to develop more stringent source control requirements that are tailored to a specific basin. Identifying Source Control Strategies in a Basin Plan Basin Plans can identify potential sources of pollution within the basin and develop strategies to eliminate or control these sources to protect beneficial uses. A Basin Plan can include the following Source Control strategies: 1. Detection and correction of illicit discharges to storm sewer systems, including the use of dry weather sampling and dye-tracing techniques; 2. Identification of existing businesses, industries, utilities, and other activities that may store materials susceptible to spillage or leakage of pollutants into the storm sewer system or to the ground via wells, drains, or sumps; 3. Elimination or control of pollutant sources identified in (2); 4. Identification and control of future businesses, industries, utilities, and other activities which may store materials susceptible to spillage or leakage of pollutants into the storm sewer system; and 5. Training and public education A Basin Plan that incorporates the standard requirements from this section as well as more stringent requirements does not require Ecology approval. What Source Control BMP’s are applicable to your project? There are no applicable source control BMPs for the site at this stage of development. The project proposes only rough grading for unknown future development. Version Date: 07/26/24 Page 32 TAB 4 (MINIMUM REQUIREMENT #4) • Minimum Requirement #4 – Preservation of Natural Drainage Systems and Outfalls 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? Yes\No. If yes, refer to section I.2.5.4 for Supplemental Guidelines for additional information. Stormwater currently discharges to Fidalgo Bay through piped outfalls. This project will maintain discharge to Fidalgo Bay. Version Date: 07/26/24 Page 33 TAB 5 (MINIMUM REQUIREMENT #5) • 1-3.4.5 Minimum Requirement #5 – On-site Stormwater Management Projects shall employ Stormwater Management BMPs in accordance with the following thresholds, standards, and lists to infiltrate, disperse, and retain stormwater runoff on site to the extent feasible without causing flooding or erosion impacts. 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 BMP’s 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? Yes (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). The project is subject to only Minimum Requirements #1-#5. If the project is Flow Control Exempt, select from the list below (Skip List 1 and List 2). o BMP T5.13 Post Construction Soils Quality and Depth o BMP T5.10A: Downspout Full Infiltration, or; o BMP T5.10B Downspout Dispersion Systems, or; o BMP T5.10C: Performated Stub-out Connections, or; o BMP T5.11 Concentrated Flow Dispersion, or; o BMP T5.12 Sheet Flow Dispersion 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. 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 X Version Date: 07/26/24 Page 34 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. The project will use BMP T5.13 Amended Soils in all landscape areas. Submittal of the Soil Managmenet Plan will be deferred. There are no roofs or other hard surfaces proposed. Version Date: 07/26/24 Page 35 TAB 6 – (MINUMUM REQUIREMENT 6 – RUNOFF TREATMENT) Refer to 1.2.5.6 and provide the required information for this Minimum Requirement. The project is not subject to Minimum Requirement #6. Version Date: 07/26/24 Page 36 TAB 7 – (MINUMUM REQUIREMENT 7 – FLOW CONTROL) Refer to 1.2.5.7 and provide the required information for this Minimum Requirement. The project is not subject to Minmum Requirement #7. Version Date: 07/26/24 Page 37 TAB 8 – (MINUMUM REQUIREMENT 8 – WETLAND PROTECTION) Refer to 1.2.5.8 and provide the required information for this Minimum Requirement. The project is not subject to Minimum Requirement #8. Version Date: 07/26/24 Page 38 TAB 9 – (MINUMUM REQUIREMENT 9 – OPERATION AND MAINTENANCE) Refer to 1.2.5.9 and provide the required information for this Minimum Requirement. The project is not subject to Minimum Requirement #9. Bathroom Rough Grading–MJB Properties Appendix 1 Appendix 1 Survey OCCUPATIONAL INDICATORS NOTE RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 1 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS TOPOGRAPHIC SURVEY & EXISTING CONDITIONS PARCEL 'K' PARCEL 'J' 2OTH STREET VA C A T E D ' R ' A V E N U E (O R D I N A N C E N O . 1 8 3 4 ) RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 6 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 4 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SEE SHEET 8 SE E S H E E T 7 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS 'R ' A V E VACATED 20TH STREET(ORDINANCE NO. 1476) VACATED 21ST STREET(ORDINANCE NO. 1476) VACATED ALLEY(ORDINANCE NO. 1476) PARCEL 'A' PARCEL 'A' 21ST STREET 2OTH STREET ' Q ' A V E RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 8 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 10 SE E S H E E T 9 SEE SHEET 6 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE TOPOGRAPHIC SURVEY & EXISTING CONDITIONS 'R' A V E 22ND STREET 'R' A V E 'R' AVE 'R ' A V E 22ND STREET ' R ' A V E ' R ' A V E VACATED ALLEY(ORDINANCE NO. 1476) RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 10 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SE E S H E E T 1 1 SEE SHEET 8 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE TOPOGRAPHIC SURVEY & EXISTING CONDITIONS Bathroom Rough Grading–MJB Properties Appendix 2 Appendix 2 Geotechnical Reports The Preliminary Infiltration Report by Coastal Geologic Services on November 27, 2019 and the Geotechnical Report prepared by PanGeo on Feburary 12, 2021 are attached in this Appendix. Geotechnical & Earthquake Engineering Consultants GEOTECHNICAL REPORT MJB North Shoreline Anacortes, Washington PROJECT NO. 21-038 February 2021 Prepared for: Merlino Properties ________________________________________________ 3213 Eastlake Avenue East, Ste B Seattle, WA 98102 Tel (206) 262-0370 Fax (206) 262-0374 Geotechnical & Earthquake Engineering Consultants February 12, 2021 Project No. 21-038 Jimmy Blais Merlino Properties 5050 First Avenue South, Suite 102 Seattle, WA 98134 Subject: Geotechnical Report Site Grading and Earthwork MJB North Shoreline, Anacortes, Washington Dear Mr. Blais, This report outlined the results and recommendations of our geotechnical study to support the design and construction of the proposed roadways and general earthwork for the site. The findings outlined in the current report is based on the results of our cone penetration tests (CPTs) completed at the site. We will update our report after completion of supplemental test borings and laboratory testing. The test borings and laboratory test results will be used to refine our settlement estimate but other findings are anticipated to remain as discussed in this report. Based on the results of our CPTs, the site is underlain by a sequence of existing granular fill, soft to medium stiff silt/clay with sand mixtures to 15 to 40 feet deep, in turn underlain by medium dense to dense sand and silty sand. The proposed roadway embankments as currently designed are appropriate. The underlying soils are also subject to liquefaction induced settlements during a strong seismic event consistent with the 2018 IBC. We appreciate the opportunity to assist you with this project. We are available to meet to discuss our findings at your convenience. Sincerely, Siew L. Tan, P.E. Principal Geotechnical Engineer i TABLE OF CONTENTS 1.0 GENERAL ............................................................................................................................... 1 2.0 SITE AND PROJECT DESCRIPTION ............................................................................... 1 3.0 SUBSURFACE EXPLORATIONS ....................................................................................... 3 4.0 SUBSURFACE CONDITIONS ............................................................................................. 3 4.1 GEOLOGY ............................................................................................................................... 3 4.2 SOIL ....................................................................................................................................... 4 4.3 GROUNDWATER ..................................................................................................................... 4 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................ 5 5.1 SEISMIC SITE CLASS ............................................................................................................... 5 5.2 SOIL LIQUEFACTION ............................................................................................................... 5 5.3 CONCEPTUAL BUILDING FOUNDATION APPROACH ................................................................ 6 5.4 SITE STRIPPING AND CLEARING ............................................................................................. 6 5.5 SELECTION OF FILL MATERIALS ............................................................................................. 7 5.6 ROADWAY CONSTRUCTION AND FILL SLOPE STABILITY ........................................................ 8 5.7 SETTLEMENT ESTIMATE AND MONITORING ........................................................................... 9 5.8 UTILITIES ............................................................................................................................. 11 5.8.1 Trench Excavations ...................................................................................................... 11 5.8.2 Dewatering ................................................................................................................... 11 5.8.3 Pipe Bedding ................................................................................................................ 12 5.8.4 Trench Backfill ............................................................................................................. 12 5.9 GENERAL EARTHWORK RECOMMENDATIONS ...................................................................... 13 5.9.1 Fill Compaction ........................................................................................................... 13 5.9.2 Wet Weather Earthwork ............................................................................................... 13 6.0 LIMITATIONS ..................................................................................................................... 14 7.0 REFERENCES ...................................................................................................................... 16 LIST OF ATTACHMENTS: Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Figure 3A Generalized Subsurface Profile A-A’ Figure 3B Generalized Subsurface Profile B-B’ Figure 4 Slope Stability Analysis – Static Condition Figure 5 Slope Stability Analysis – Pseudo Static Condition Figure 6 Slope Stability Analysis – Post-Liquefaction Condition Figure 7 Settlement Plate Detail Appendix A Summary CPT Logs 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 1 GEOTECHNICAL REPORT SITE GRADING AND EARTHWORK MJB North Shoreline, Anacortes, WASHINGTON 1.0 GENERAL This report presents the results of our geotechnical engineering study to support the proposed grading activities at the MJB North Shoreline property in Anacortes, Washington. Our service scope to date included conducting a site reconnaissance, reviewing readily available geologic data, advancing ten cone penetration tests at the site, and developing the conclusions and recommendations presented in this report. 2.0 SITE AND PROJECT DESCRIPTION The project site is in Anacortes, Washington. It borders Q Avenue to the west, Fidalgo Bay to the east, 17th Avenue to the north, and 22nd Avenue to the South. The approximate location of the site is shown in the attached Figure 1. The site has an upland area of about 28 acres. The ground surface descends gently from Q Avenue to the shore of Fidalgo Bay. The topographic relief is about 10 feet between Q Avenue and the shoreline. The site is mostly vacant, with a few storage buildings located along the west side of the site. We understand that the property will be developed in phases and the final development plan is currently being developed. When completed, as currently envisaged, the development may include residential units, hotels, retail, restaurants, an event center, and parking lots. A new north-south trending roadway (T Avenue) will be constructed in the middle of the site, connecting 17th Avenue on the south and 22nd Avenue on the north. The proposed T Avenue will be about 1,600 feet long. The existing 17th Avenue, between Q Avenue and T Avenue, will also be regraded. A preliminary conceptual site layout is shown in Plate 1 on the following page. We understand that fill will be placed to raise the site grade for the proposed development. Along the proposed T Avenue, as much as about 10 feet of fill will be placed above the existing grade. Along 17th Avenue, the new fill will generally be less than about 4 feet above the existing grade. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 2 Plate 1. Preliminary conceptual site plan. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 3 3.0 SUBSURFACE EXPLORATIONS PanGEO completed ten Cone Penetration Tests (CPT-1 to CPT-10) on February 1 and 8, 2021. The CPTs were performed by ConeTec Inc. at the approximate locations indicated on the attached Figure 2. The CPT probes were advanced to depths of about 56 to 97 feet below the existing ground surface when refusal was met. ConeTec used an instrumented cone approximately 1½ inches in diameter, which is pushed into the soil at a steady rate to measure tip resistance (Qt), side friction (Fs), pore water pressure (u), soil behavior type, and correlated SPT blow counts. The readings on the soil are taken at about 2-inch vertical intervals, and provide a nearly continuous readout of soil stratigraphy, strength, and other parameters. Summary CPT logs are included in Appendix A of this report. 4.0 SUBSURFACE CONDITIONS 4.1 GEOLOGY Our interpretation of the geologic conditions at the site vicinity is based on a review of the Geologic Map of the Anacortes South and La Conner 7.5-minute Quadrangles (Dragovich, at al, 2000), and the Geologic map of the Bellingham 1:100,000 Quadrangle (Lapen, 2000). In summary, a portion of downtown Anacortes east of Commercial Avenue, including the project site, was raised to current elevations by placing fill over Nearshore Deposits (Qn). Nearshore deposits are described as interbedded fine sand, silt, and clay with some peat and organic deposits. The composition of fill can be highly variable and are generally relatively loose in nature. West of the areas that were previously filled, the surficial geology is mapped as Glaciomarine Drift (Qgdm) from the Everson interstade of the Fraser glaciation. The Glaciomarine Drift is characterized as soft silt and clay with sand lenses. South of the project site near the shoreline is mapped as Glaciomarine Outwash (Qgom) from the Everson interstade of the Fraser Glaciation. The Glaciomarine Outwash is characterized as sand and sandy gravel with some silt and clay interbeds. The Glaciomarine Drift and Outwash Deposits are likely underlain by older till, which has been overridden by glacial ice and is consequently very dense/hard. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 4 4.2 SOIL The results from our CPTs indicate that the subsurface conditions at the site are relatively consistent. The following summarizes the subsurface conditions encountered in our CPTs: Unit 1: Fill – At each CPT location, we encountered existing surficial fill that ranged from 3 to 8 feet thick. The composition of the fill material varied across the project area, generally consisting of gravel, sand, and silty mixtures. The relative density of the fill varied from loose to very dense. Unit 2: Glaciomarine Drift – Below the surficial fill, we encountered a layer of soft to medium stiff, silt and clay mixtures with sand lenses. Based on the variable and mixed soil behavior type and the relatively soft consistency, we interpret this soil unit as Glaciomarine Drift mapped near the site. The thickness of this soil unit varies across the site, and its bottom ranges from 17 to 40 feet below the existing ground surface. This soil unit is moderately compressible and could experience long term settlement when loads are applied. Unit 3: Glaciomarine Outwash (Qgom) – Below the Glaciomarine Drift we encountered a layer of medium dense to very dense sand and sand mixtures with silt and clay. This soil unit appeared to have occasional thick layers of uniform consistency. Based on the dense and sandy consistency, we interpret this soil unit as the nearby mapped Glaciomarine Outwash Deposits. This soil unit extended to the bottom of each CPT before reaching practical refusal between 56 and 97 feet deep. We also generated two subsurface profiles to depict the subsurface conditions encountered in our CPTs. The subsurface profiles are included in Figures 3A and 3B. 4.3 GROUNDWATER Groundwater table was generally estimated around 5 to 6 feet below the existing grade using dissipation tests and interpolation from the dynamic pore pressure. Plots of the recorded dissipation tests can be seen in Appendix A. It should be noted that groundwater elevations may vary depending on the season, local subsurface conditions, tide elevations, and other factors. Groundwater levels are normally highest during the winter and early spring. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 5 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 SEISMIC SITE CLASS We anticipate the seismic design of the buildings will be based on the 2018 International Building Code (IBC). The IBC seismic design parameters are in part based on the site soil conditions and site classifications defined in Chapter 20 of ASCE 7-16. According to Chapter 20 of ASCE 7-16, the site soil should be classified as Site Class F because of its liquefaction potential during a strong seismic event (see discussions regarding liquefaction in Section 5.2 of this report). Review of Section 20.3.1 of ASCE 7-16 indicates that for Site Class F a site-specific ground response analysis shall be performed unless the exception to Section 20.3.1 is applicable. Section 20.3.1 of ASCE 7 states that “For structures having fundamental periods of vibration equal to or less than 0.5s, site response analysis is not required to determine spectral accelerations for liquefiable soils. Rather, a site class is permitted to be determined in accordance with Section 20.3 and the corresponding values of Fa and Fv determined from Tables 11.4-1 and 11.4-2.” In other words, for structures with a period of vibration equal to or less than 0.5 second and situated on liquefiable soils, the ASCE 7-16 exception allows the values of Fa and Fv for liquefiable soils be taken equal to the values of site class determined without regard to soil liquefaction. Generally, buildings that are less than 5 stories in height typically meet this exception but should be verified by the structural engineer. Based on the results of our subsurface explorations, the average correlated N60 value was greater than 15 in all 10 CPTs. As, such, if the vibration period for a proposed building is less than 0.5 second, Site Class D may be assumed for determining site coefficients without the needs for a site- specific ground response analysis. However, if the fundamental period of vibration for the proposed buildings exceeds 0.5 seconds, Site Class F should be used. PanGEO can perform the site-specific ground response analysis when requested. 5.2 SOIL LIQUEFACTION Liquefaction occurs when saturated predominately sand and silt soils are subjected to cyclic loading. This causes the porewater pressure to increase in the soil, thereby reducing the inter- granular stresses. As the inter-granular stresses are reduced, the shearing resistance of the soil decreases. If pore pressures develop to the point where the effective stresses acting between the grains become zero, the soil particles will be in suspension and behave like a viscous fluid. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 6 Typically, loose, saturated granular soils have the greatest potential for liquefaction, while more dense soil deposits with higher silt or clay contents have a lesser potential. Soil liquefaction may cause the temporary loss/reduction of foundation capacity, lateral movement of sloping ground, and ground settlement. We evaluate the potential for soil liquefaction and calculated the magnitude of liquefaction-induced settlement based on the results of our CPTs. Our analysis uses the methods proposed by Idriss and Boulanger (2014) and Cetin et al. (2009) and was performed based on an earthquake magnitude of 7.5 and a PGA of 0.48g, which are consistent with the 2018 IBC. In summary, our results indicate that liquefaction could extend to depths greater than 70-plus feet. However, liquefaction-induced settlement deeper than 60 feet should not manifest itself to the surface (Cetin et al., 2009). We estimate that surficial settlement due to soil liquefaction should be no more than 4 to 6 inches. This magnitude of settlement would not impact the grading as currently designed. A more detailed analysis will be performed during the final design of the proposed buildings. Based on the relatively level site grade and the 100-foot setback for building development along the shoreline, it is our opinion that the overall risk for lateral spreading is low and should not impact the proposed development. 5.3 CONCEPTUAL BUILDING FOUNDATION APPROACH Selection of building foundation types depend on several factors, including the site soil conditions, building types, design columns loads, and desired level of performance. PanGEO will provide design- level recommendations during the final design phase of the proposed buildings. For general planning purposes, for wood-framed structures less than three floors in height, we anticipate that the use of conventional footings, a mat foundation, or a structural slab with thickened edges are likely adequate. For taller buildings, the use of ground improvement methods maybe necessary to support these taller buildings on shallow foundations. Alternatively, the use of piles may also be considered. 5.4 SITE STRIPPING AND CLEARING Prior to placement of new fill to raise the site grade, general site clearing should include removal of existing structures, debris, refuse, and other deleterious material. Existing topsoil, where not combined with refuse or other deleterious material, may be stripped and stockpiled for use in landscape areas following final grading of site improvements. In no case should the stripped or Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 7 grubbed materials be used as structural fill or mixed with material to be used as structural fill. The stripped materials may be “wasted” on site in non-structural landscaping areas or they should be exported from the site. Existing utility pipes to be abandoned should be filled or removed so they do not provide a conduit for water flow and potential loss of soils adjacent to the pipes. 5.5 SELECTION OF FILL MATERIALS Import materials to raise the site grade and to construct the roadway should generally consist of Gravel Borrow (Section 9-03.14(1), WSDOT Standard Specifications, 2020), or Select Borrow (Section 9-03.14(2), WSDOT Standard Specifications, 2020). The gradational requirements for Gravel Borrow and Select Borrow are summarized in Table 1, below: Table 1 – Gradational Requirements based on Percent Passing by Weight Sieve Size Gravel Borrow1 Select Borrow2 6-inch - 99 - 100 4-inch 99 - 100 - 3-inch - 75 - 100 2-inch 75 -80 - #4 30 max. - #40 - 50 max. #200 7.0 max 10.0 max Sand Equivalent 50 min. 30 min. 1. Gravel Borrow gradation requirements per Section 9-03.14(1) of WSDOT Standard Specification, 2020. 2. Select Borrow gradation requirements per Section 9-03.14(1) of WSDOT Standard Specification, 2020. The fill should be compacted to at least 95 percent of its maximum dry density, determined in accordance with Modified Proctor Tests (ASTM D1557). The use of recycled materials such as recycled crushed concrete and recycled asphalt may also be considered, provided that these materials will be allowed by the permitting agencies. Recycled crushed asphalt, if used, it should be blended with soil aggregate and the blended products should contain no more than 20% of recycled asphalt. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 8 5.6 ROADWAY CONSTRUCTION AND FILL SLOPE STABILITY Based on our review of the grading plans prepared by KPFF, dated 8/8/2020, as much as 10 feet of fill will be placed to raise the grade along the centerline of the proposed T Avenue (A-Line), and the embankment slopes will be graded to 4H:1V (horizontal:vertical). The weight of the new fill is expected to result in settlement of the soft to medium stiff silt and clay underlying the site (see additional discussions in Section 5.7, blow). The settlement is time-dependent and is expected to occur over a period of time. Utilities located within the footprint of the roadway embankment should be installed after the consolidation settlement is complete. We performed a quantitative slope stability analysis of the proposed roadway embankment in the static, seismic (pseudo-static), and post-liquefaction conditions. We performed our slope stability analysis using the program SLIDE2 (Slide) by Rocscience Inc. Slide is a two-dimensional limit equilibrium slope stability analysis program. Our analysis used the Janbu Corrected Method to determine potential failure. The following discusses our model and analysis: Soil Parameters: A summary of the input soil parameters is provided in Table 2 below. Input parameters were selected based on general estimates provided in the WSDOT Geotechnical Design Manual, CPT data, and our judgement and experience with similar soils. The undrained residual strength (post-liquefaction) of the Glaciomarine Drift deposit was determined using the methodology described in Section 6-2.2 in the WSDOT Geotechnical Design Manual (2019). The Glaciomarine Drift was divided into three 10-foot-thick layers to more accurately reflect the increased residual strength with depth. Table 2 – SLIDE Soil Input Parameters oil Type Unit Weight (pcf) Friction Angle (degrees) Cohesion (psf) Preload Fill 120 34 0 Existing Fill 120 32 0 Glaciomarine Drift 115 26 150 Glaciomarine Drift (Post-Liquefaction Layer 1) 115 0 230 Glaciomarine Drift (Post-Liquefaction Layer 2) 115 0 250 Glaciomarine Drift (Post-Liquefaction Layer 3) 115 0 266 Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 9 Groundwater: The groundwater table was modeled at the contact between the existing fill and Glaciomarine Drift. Seismic Parameters: Seismic design parameters for the site were developed in conformance with the 2018 IBC, which specifies a design earthquake having a 2 percent probability of occurrence in 50 years (return interval of 2,475 years). A spectral response acceleration was obtained from the USGS Earthquake Hazards Program Interpolated Probabilistic Ground Motion website (2008 data) for the project latitude and longitude, based on Site Class D for stiff soil. We obtained a peak ground acceleration (PGA) of 0.48g. One-half of the PGA, or 0.24g, as used in our slope stability analysis, consistent with the local practice. Results: the results of our slope stability analysis are summarized in the attached Figures 4, 5, and 6, for the static, pseudo-static (seismic), and post-liquefaction. In summary, the calculated minimum global factors of safety for the static, seismic, and post-liquefaction conditions were about 2.78, 1.34, and 1.37, respectively. Based on the results from our analysis, the global stability of the proposed roadway embankment meets the minimum factor of safety requirement of 1.5 for the static condition, 1.1 for the seismic condition, and 1.0 for the post-liquefaction condition. 5.7 SETTLEMENT ESTIMATE AND MONITORING Under the proposed new fill, the soft to medium stiff silt and clay (Soil unit 2) is expected to settle. Based on the general consistency of the soils from the CPTs, we estimate that the settlement from the proposed fill placement should be no more than about 3 to 4 inches. The estimated settlement should occur within about 3 months after placement of the fill. However, we will refine our estimate of the settlement in our upcoming report once our test borings and laboratory test program and engineering analysis are completed. Construction of the proposed improvements such as underground utilities, buildings, pavements should be commenced only after the consolidation settlement of the soft to medium stiff silt and clay has stabilized. A settlement monitoring program should be implemented to confirm that settlement is occurring as expected during preload period and to verify the end of consolidation settlement such that the site can be released for construction. Monitoring of settlements should be performed using settlement plates, placed at a grid spacing of generally no greater than about 100 feet apart, in areas where the site grade will be raised by more than 4 feet. A schematic detail of settlement plate is shown in the attached Figure 7. Other considerations for settlement monitoring are outlined below: Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 10 • The settlement plates should be installed on firm ground prior to placing any fill. Locations of settlement plates should be clearly marked and readily visible (red flagged) to equipment operators. • The contractor should maintain at least a 5-foot horizontal clearance with heavy equipment. Fill within 5 feet of the settlement plates should be compacted with small equipment to project specifications. In the event of damage to a settlement plate or measurement rod, the contractor should immediately notify the geotechnical engineer and should restore the settlement plate to working order. • A licensed land surveyor should be retained to monitor the settlement plates. Initial readings should be taken on top of the measurement rod and at the adjacent ground level prior to fill placement. For ease in handling, the measurement rod and casing can be installed in 5-foot sections. As fill progresses, couplings should be used to install additional lengths. Continuity should be maintained when adding extensions, by reading the top of the measurement rod, then immediately adding the new section and reading the top of the added rod. Both readings should be recorded. • After initial placement, readings should be taken twice weekly during fill placement, once weekly after completion of fill placement for at least 4 weeks. Depending on the project schedule and results of the monitoring, the monitoring frequency may be adjusted by the geotechnical engineer accordingly. • The measurement rod readings should be to the nearest 0.01 foot (or the nearest 0.005 foot if possible); fill elevations should be measured to the nearest 0.1 foot. All elevations should be referenced to a benchmark located on stable ground at least 100 feet from the preload areas. Readings should be submitted in a timely fashion to the geotechnical engineer, who should analyze the settlement data, to provide a basis for determining when the desired effect of preloading has been achieved, and the consolidation settlement has been completed. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 11 5.8 UTILITIES Utilities should be installed after completion of the pre-load, to mitigate the risk of post- construction settlement. 5.8.1 Trench Excavations We anticipate that utilities will be installed after placement of the new fill. As such, utility trench excavations are anticipated to extend through a sequence proposed fill, the existing fill, and soft to medium stiff silt and clay. Temporary excavations greater than 4 feet deep should be properly sloped or shored. All temporary excavations should be performed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for maintaining safe excavation slopes and/or shoring. For planning purposes, the temporary excavations may be sloped as steep as 1H:1V for excavations located above the groundwater table but should be re-evaluated in the field during construction based on actual observed soil conditions. Temporary excavation located below the groundwater table may be sloped as steep as 1.5H:1V, provided the excavation is adequately dewatered. During wet weather, the cut slopes may need to be flattened to reduce potential erosion. Conventional trench shoring systems such as trench boxes or steel sheets with hydraulic bracing may be used to limit the excavation. For design purposes, the contractor may utilize an equivalent fluid weight of 35 pcf to represent the lateral earth pressures on the shoring. This pressure should be increased to 45 pcf for shoring with a maximum 1H:1V backslopes above the shoring. Surcharges from soil stockpiles and/or equipment traffic located within a horizontal distance equal to the depth of the excavation should also be applied to the shoring design. 5.8.2 Dewatering Groundwater is estimated between 6 to 10 feet below the existing grade at the time of our exploration. If excavation extends below the water table, control of groundwater may be necessary. The rate of groundwater discharge will largely depend on the groundwater level at the time of excavation, the depth of excavation, the actual soil conditions (sand vs. silt/clay), and the sequencing of the excavation. However, it is our opinion that the dewatering can likely be accomplished with sumps and pumps. If groundwater is encountered during excavation, the bottom of the excavation should be sloped to one or more shallow sump pits. The collected water can then be pumped from these pits to a Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 12 positive and permanent discharge. Depending on the magnitude of such seepage, it may also be necessary to interconnect the sump pits by a system of connector trenches. 5.8.3 Pipe Bedding Pipe bedding material, placement, compaction, and shaping should be in accordance with the project specifications and the pipe manufacturer’s recommendations. As a minimum, the pipe bedding material should meet the requirements for Gravel Backfill for Pipe Zone Bedding in Section 9-03.12(3) of the WSDOT Standard Specifications (2020). Bedding material should be placed in accordance with the recommendations provided in section 7-08.3(1)C for Pipe Zone Bedding in the WSDOT’s Standard Specifications (2020) to ensure proper pipe support and protection. The excavated trench bottom should be firm and unyielding or be compacted to such a condition prior to placement of bedding material. 5.8.4 Trench Backfill In general, the trench backfill may consist of the existing granular fill that is present at the site, or the import soils that will be used to raise the site grade. The native soils (Soil Unit 2) below the existing fill contain significant amounts of fines and in our opinion not appropriate for use as trench backfill. The placement of trench backfill should be in accordance with Section 7-08.3(3) of WSDOT Standard Specifications (2020). The first zone of backfill extending from the bedding material to at least 6 inches above the crown of the pipe should consist of select free-draining granular material to reduce the compaction effort required and resulting stresses on the pipe. The granular material should be well-graded, less than 1½ inch in maximum size, and less than 10 percent passing the No. 200 sieve, such as Gravel Backfill for Pipe Zone Bedding in section 9-03.12(3) of WSDOT’s Standard Specifications (2020) or CSBC. During placement of the initial lifts, the trench backfill should not be bulldozed into the trench or dropped directly on the pipe. Furthermore, heavy vibratory equipment should not be permitted to operate directly over the pipe until a minimum of 2 feet of backfill has been placed above the crown. The trench backfill material should be placed in 8- to 12-inch, loose lifts and compacted to at least 95% of the Modified Proctor (ASTM D1557). Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 13 5.9 GENERAL EARTHWORK RECOMMENDATIONS 5.9.1 Fill Compaction In general, except in landscaping areas, all fills should be compacted to 95 percent of its maximum dry density, as determined using ASTM D 1557 (Modified Proctor). The procedure to achieve proper density of a compacted fill depends on the size and type of compacting equipment, soil moisture content, the number of passes, thickness of the layer being compacted, and certain soil properties. In areas where the use of heavy equipment may be restricted, smaller equipment can be used, but the soil must be placed in thin enough layers to achieve the required relative compaction. 5.9.2 Wet Weather Earthwork In our opinion, because the site soils generally contain a considerable amount of fines and are considered moisture sensitive, earthwork construction performed during the drier summer months likely will be more economical. If the earthwork will be performed during wet weather, the on- site soils could become saturated and lead to difficult working conditions. In addition, saturated soils could become difficult or impossible to adequately compact. Soft and unstable soil conditions due to inclement weather, disturbance, and poor drainage will require removal and replacement with granular structural fill. To reduce the risks of soil disturbance due to inclement weather conditions, we recommended that, as a minimum, the following recommendations be incorporated into the contract specifications. • Earthwork should be performed in small areas to minimize exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. • The size and type of construction equipment used may have to be limited to prevent soil disturbance. • During wet weather conditions, the allowable fines content of Gravel Borrow should be reduced to no more than 5 percent by weight based on the portion passing ¾-inch sieve. The fines should be non-plastic. • The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 14 • The ground surface within the construction area should be sealed by a smooth drum vibratory roller, or equivalent, and under no circumstances should soil be left uncompacted and exposed to moisture. • Bales of straw and/or geotextile silt fences should be strategically located to control surface water and erosion. 6.0 LIMITATIONS We have prepared this report for Merlino Properties and the project design team. Recommendations contained in this report are based on a site reconnaissance, a subsurface exploration program, review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed-upon scope of work. Variations in soil conditions may exist between the locations of the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors’ methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on-site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 15 It is the client’s responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor’s option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. We appreciate the opportunity to be of service. Sincerely, PanGEO Inc. 2/12/2020 Bryce Townsend, P.E. Siew L. Tan, P.E. Project Geotechnical Engineer Principal Geotechnical Engineer Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 16 7.0 REFERENCES Boulanger, R.W., Idriss, I.M., 2014, CPT and SPT Based Liquefaction Triggering Procedures, University of California at Davis, Department of Civil & Environmental Engineering. Cetin at al. (2009), Probabilistic Model for the Assessment of Cyclically Induced Reconsolidation (Volumetric) Settlements, Middle East Technical University, 06531, Ankara, Turkey, Department of Civil Engineering. International Code Council, 2018, International Building Code (IBC), 2018. United States Geological Survey, 2008, Earthquake Hazards Program, Interpolated Probabilistic Ground Motion for the Conterminous 48 States by Latitude and Longitude, 2008 Data, accessed via: http://earthquake.usgs.gov/designmaps/us/application.php Washington Administrative Code (WAC), 2013, Chapter 296-155 - Safety Standards for Construction Work, Part N - Excavation, Trenching, and Shoring. WSDOT, 2019, Geotechnical Design Manual, M46-03.12. WSDOT, 2020, Standard Specifications for Road, Bridges, and Municipal Construction. 21-038 1 VICINITY MAP Figure No.Project No. Base Map: Seattle City GIS NORTH Not to Scale Proposed Development MJB North Shoreline Anacortes, Washington Project Site 21 - 0 3 8 F i g . 1 - V i c i n i t y M a p 1 / 2 9 / 2 1 ( 1 : 4 0 : 2 7 ) Notes: 1. See Figure 2 for location of Section A-A'. 2. Ground surface elevations based on the contours shown on Plan Sheet C0.10, dated 8/28/2020, by KPFF. 3. See report text for additional discussions on subsurface conditions. 4. The generalized soil profile is based on widely-spaced probes. Soil conditions may vary over a small distance, and the actual subsurface conditions may be different from the generalized soil profile depicted in this figure. MJB North Shoreline Anacortes, Washington GENERALIZED SUBSURFACE PROFILE A-A' Project No. Figure No. 21-038 3A21 - 0 3 8 F i g . 3 A - S u b s u r f a c e P r o f i l e 2 / 1 2 / 2 1 ( 1 : 3 3 : 1 6 ) Legend: Fill Pre-Olympia Glacial Till (Qpogt) Pre-Olympia Fine-Grained Deposits (Qpof) PG-5 Graphics Legend 48 21 50/5 88 31 42 31 50/3 SPT N-valueGroundwater Level Soil Unit Boundaries Topographic Surface -100 -50 0 50 100 150 200 250 300 350 400 450 500 550 Distance (ft) -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 0 200 400 Qt (tsf)0 200 400 Qt (tsf) ? A A' Approx. Scale: 1" : 50' R Ave PLExisting Building Unit 1 - Existing Fill Unit 2 - Glaciomarine Drift Unit 3 - Glaciomarine Outwash Sand Soil Unit Legend: 0 40 80 120160200 Qt (tsf) Graphics Legend Cone Tip Resistance GroundwaterLevel Soil Unit Boundaries CPT # Topographic Surface 100' SETBACK FROM SHORELINEADJACENT WEST PROPERTY EXISTING BUILDING ~20' S OFFSET CPT-3 ~10' N OFFSET CPT-4?? ??? ? ?? ?? ? ? ?? ? ? ?? Notes: 1. See Figure 2 for location of Section B-B'. 2. Ground surface elevations based on the contours shown on Plan Sheet C0.10, dated 8/28/2020, by KPFF. 3. See report text for additional discussions on subsurface conditions. 4. The generalized soil profile is based on widely-spaced probes. Soil conditions may vary over a small distance, and the actual subsurface conditions may be different from the generalized soil profile depicted in this figure. MJB North Shoreline Anacortes, Washington GENERALIZED SUBSURFACE PROFILE B-B' Project No. Figure No. 21-038 3B21 - 0 3 8 F i g . 3 A - S u b s u r f a c e P r o f i l e 2 / 1 2 / 2 1 ( 1 : 3 2 : 4 3 ) Legend: Fill Pre-Olympia Glacial Till (Qpogt) Pre-Olympia Fine-Grained Deposits (Qpof) PG-5 Graphics Legend 48 21 50/5 88 31 42 31 50/3 SPT N-valueGroundwater Level Soil Unit Boundaries Topographic Surface 0 100 200 300 400 500 600 700 800 900 1000 Distance (ft) -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 0 200 400 Qt (tsf) 0 200 400 Qt (tsf)0 200 400 Qt (tsf) 0 200 400 Qt (tsf) B B' Approx. Scale: 1" : 50' R Ave PLExisting Building Unit 1 - Existing Fill Unit 2 - Glaciomarine Drift Unit 3 - Glaciomarine Outwash Sand Soil Unit Legend: 0 40 80 120160200 Qt (tsf) Graphics Legend Cone Tip Resistance GroundwaterLevel Soil Unit Boundaries CPT # Topographic Surface 100' SETBACK FROM SHORELINE Q AVE EXISTINGBUILDING ~160' N OFFSET CPT-10 ~200' S OFFSETCPT-7~80' N OFFSETCPT-8 ~90' N OFFSETCPT-9 FIDALGO BAY?? ??? ? ?? ?? ? ? ?? ? Phi (deg) Cohesion (psf) Strength Type Unit Weight (lbs/ft3)ColorMaterial Name 340Mohr‐ Coulomb120Preload Fill 320Mohr‐ Coulomb120Existing Fill 26150Mohr‐ Coulomb115Glaciomarine Drift Global Minimums Method: Janbu Corrected FS: 2.78 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 60 40 20 0 -2 0 0 20 40 60 80 100 120 Figure No.4Project No.21-038 SLOPE STABILITY ANALYSIS STATIC CONDITION Project MJB North Shoreline Anacortes, Washington SLIDEINTERPRET 9.008 W Phi (deg) Cohesion (psf) Strength Type Unit Weight (lbs/ft3) ColorMaterial Name 340Mohr‐ Coulomb120Preload Fill 320Mohr‐ Coulomb120Existing Fill 26150Mohr‐ Coulomb115Glaciomarine Drift Global Minimum Method: Janbu Corrected FS: 1.337 0.24 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 40 20 0 -2 0 0 20 40 60 80 100 120 Figure No.5Project No.21-038 SLOPE STABILITY ANALYSIS PSEUDO-STATIC CONDITION Project MJB North Shoreline Anacortes, Washington SLIDEINTERPRET 9.008 W Phi (deg) Cohesion (psf) Strength Type Unit Weight (lbs/ ft3)ColorMaterial Name 340Mohr‐ Coulomb120Preload Fill 320Mohr‐ Coulomb120Existing Fill 0230Mohr‐ Coulomb115Post‐Liq 1 0250Mohr‐ Coulomb115Post‐Liq 2 0266Mohr‐ Coulomb115Post‐Liq 3 Global Minimum Method: Janbu Corrected FS: 1.368 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 40 20 0 -2 0 0 20 40 60 80 100 120 Figure No.6Project No.21-038 SLOPE STABILITY ANALYSIS POST-LIQUEFACTION CONDITION Project MJB North Shoreline Anacortes, Washington SLIDEINTERPRET 9.008 Figure No.Project No. NOTES: 1.Locations of settlement plates shall be clearly marked and readily visible to equipment operators. 2.Contractor shall maintain at least 5 feet of horizontal clearance for heavy equipment from the base of settlement plates. Fill within 5 feet of settlement plates shall be compacted using hand operated equipment. 3.In the event of damage to settlement plates, contractor shall immediately notify Engineer and shall be responsible for restoring the settlement plates to working order. 4.Install plates on firm ground or on sand pads if needed for stability. Take initial readings on top of the rod and at adjacent ground level prior to placement of fill. 5.For ease in handling, rod and casing are usually installed in short sections. As fill progresses, couplings are used to installed additional lengths. Continuity is maintained by reading the top of the measurement rod, then immediately adding the new section and reading the top of the added rod. Both readings should be recorded. 6.Record the elevations of the top of the measurement rod at pre- determined time intervals, but no less than once a week. Each time, note the elevation of the adjacent ground surface. 7.Read the measurement rods to the nearest 0.01 ft, or 0.005 ft if possible. Note the fill elevation to the nearest 0.1 ft. 8.The elevations should be referenced to a temporary benchmark located on stable ground at least 100 feet from the zone of influence of the embankment and surcharge (preload fill). MJB North Shoreline Anacortes, Washington 21-038 7 SETTLEMENT PLATE DETAIL 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. APPENDIX A SUMMARY CPT LOGS 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 08:31 Site: Anacortes MJB Shoreline Sounding: CPT-1 Cone: 529:T1500F15U35 Max Depth: 19.550 m / 64.14 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP01.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50495 Long: -122.60883 UndefinedStiff Sand to Clayey SandStiff Sand to Clayey Sand Stiff Sand to Clayey Sand Sand Mixtures Silt Mixtures Clays Silt MixturesSand MixturesSand Mixtures Silt Mixtures Clays Silt Mixtures Sand Mixtures Silt MixturesClaysSilt MixturesStiff Sand to Clayey Sand Very Stiff Fine Grained Stiff Sand to Clayey Sand Sand MixturesSand Mixtures Sand Mixtures Sands Sand Mixtures Sand MixturesVery Stiff Fine GrainedSand MixturesSand Mixtures Stiff Sand to Clayey Sand 35.2 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 09:52 Site: Anacortes MJB Shoreline Sounding: CPT-2 Cone: 529:T1500F15U35 Max Depth: 27.450 m / 90.06 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP02.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50495 Long: -122.60721 Undefined Sand Mixtures Silt Mixtures Sand MixturesSilt Mixtures Silt MixturesSilt Mixtures Sand Mixtures Silt Mixtures Silt Mixtures Sand MixturesSilt MixturesSilt MixturesStiff Sand to Clayey Sand Stiff Sand to Clayey SandVery Stiff Fine GrainedStiff Sand to Clayey SandStiff Sand to Clayey SandStiff Sand to Clayey Sand Stiff Sand to Clayey SandStiff Sand to Clayey Sand Sand Mixtures Sand Mixtures Sand Mixtures Stiff Sand to Clayey Sand Sand Mixtures Very Stiff Fine GrainedStiff Sand to Clayey Sand Very Stiff Fine Grained Sand Mixtures Very Stiff Fine Grained Silt Mixtures Sand Mixtures Silt Mixtures Sand MixturesSilt Mixtures Sand Mixtures Sands Sand Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Undefined 14.4 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 12:06 Site: Anacortes MJB Shoreline Sounding: CPT-3 Cone: 529:T1500F15U35 Max Depth: 23.575 m / 77.34 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP03.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50571 Long: -122.60880 Undefined Stiff Sand to Clayey SandSilt Mixtures Sand Mixtures Very Stiff Fine Grained Stiff Sand to Clayey SandSilt Mixtures Silt MixturesSand Mixtures Sand MixturesSand Mixtures Sand Mixtures Sand Mixtures Silt Mixtures Sand MixturesSilt Mixtures Sand MixturesSand MixturesSilt MixturesStiff Sand to Clayey Sand Sands Sand Mixtures Sands SandsSand MixturesSands Sand Mixtures Sands Sand MixturesSand MixturesSands Sands Sand Mixtures Undefined 3.6 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 03:28 Site: Anacortes MJB Shoreline Sounding: CPT-4 Cone: 529:T1500F15U35 Max Depth: 24.050 m / 78.90 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP04.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50590 Long: -122.60744 Undefined SandsSand MixturesSands Silt Mixtures ClaysClays Silt Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Clays Silt Mixtures Sand MixturesSands Sands Sands Sand MixturesSand Mixtures Sands Very Stiff Fine Grained Very Stiff Fine GrainedStiff Sand to Clayey Sand SandsStiff Sand to Clayey Sand Sands Stiff Sand to Clayey Sand SandsSand MixturesSand Mixtures Sands Sands Sand Mixtures Sand Mixtures Sands Sand Mixtures Sand Mixtures Sand Mixtures 3.7 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 04:49 Site: Anacortes MJB Shoreline Sounding: CPT-5 Cone: 529:T1500F15U35 Max Depth: 29.675 m / 97.36 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP05.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50675 Long: -122.61047 Undefined Silt Mixtures Sand Mixtures Silt MixturesStiff Sand to Clayey Sand Silt Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Silt Mixtures Silt Mixtures Clays Silt MixturesSand Mixtures Silt MixturesSand Mixtures Sand MixturesStiff Sand to Clayey SandStiff Sand to Clayey Sand Sand Mixtures Stiff Sand to Clayey Sand SandsSand Mixtures Sand MixturesStiff Sand to Clayey Sand Very Stiff Fine GrainedSands Sand Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Very Stiff Fine Grained Sand Mixtures Silt MixturesSilt Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Sands Silt Mixtures Sand Mixtures Undefined Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 08:16 Site: Anacortes MJB Shoreline Sounding: CPT-6 Cone: 529:T1500F15U35 Max Depth: 17.100 m / 56.10 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP06.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50700 Long: -122.60816 Undefined Gravelly Sand to SandGravelly Sand to Sand Gravelly Sand to SandStiff Sand to Clayey Sand Sand MixturesSilt MixturesSilt MixturesSand Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Silt Mixtures ClaysClaysVery Stiff Fine Grained Sand MixturesSands Stiff Sand to Clayey SandSand Mixtures Sand Mixtures Stiff Sand to Clayey Sand Sand Mixtures Very Stiff Fine GrainedSilt Mixtures Very Stiff Fine GrainedSand MixturesSilt Mixtures Sand MixturesSand Mixtures Sand Mixtures Silt Mixtures Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 09:14 Site: Anacortes MJB Shoreline Sounding: CPT-7 Cone: 529:T1500F15U35 Max Depth: 22.950 m / 75.29 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_SP07.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50767 Long: -122.60973 UndefinedGravelly Sand to Sand Sands Silt Mixtures Sand MixturesSilt MixturesSilt MixturesSilt Mixtures Silt Mixtures Clays Very Stiff Fine GrainedSand MixturesSand MixturesStiff Sand to Clayey Sand SandsVery Stiff Fine GrainedSand Mixtures Sand MixturesStiff Sand to Clayey SandSand Mixtures Sand Mixtures Sand MixturesStiff Sand to Clayey Sand Sand Mixtures Sands SandsSilt Mixtures Sand Mixtures Sands Sand MixturesSilt Mixtures Sand Mixtures Very Stiff Fine Grained Sand Mixtures Silt Mixtures Sand Mixtures Undefined 27.0 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 10:57 Site: Anacortes MJB Shoreline Sounding: CPT-8 Cone: 529:T1500F15U35 Max Depth: 21.925 m / 71.93 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP08.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50843 Long: -122.61024 UndefinedSand MixturesSand MixturesSilt Mixtures Sand MixturesSilt Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Silt Mixtures Clays Silt Mixtures Sand MixturesSands Silt MixturesSand Mixtures Sand Mixtures Sands Sand Mixtures Sands Sand MixturesSands Silt Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Undefined 34.6 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 02:06 Site: Anacortes MJB Shoreline Sounding: CPT-9 Cone: 529:T1500F15U35 Max Depth: 22.125 m / 72.59 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP09.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50842 Long: -122.60853 Undefined Sands Sand Mixtures Silt Mixtures Sand MixturesSand MixturesSilt MixturesSilt Mixtures Silt Mixtures Silt MixturesClaysSilt MixturesSand Mixtures Silt Mixtures Silt Mixtures Sand MixturesSand Mixtures Sand MixturesSand MixturesStiff Sand to Clayey SandVery Stiff Fine Grained Very Stiff Fine Grained Sand MixturesSandsSand Mixtures SandsStiff Sand to Clayey Sand SandsSand Mixtures SandsSands SandsStiff Sand to Clayey Sand Sands Sand Mixtures Sands Sand Mixtures Sand Mixtures Sands Sand Mixtures Sands Sands Sand Mixtures 24.7 33.3 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 03:36 Site: Anacortes MJB Shoreline Sounding: CPT-10 Cone: 529:T1500F15U35 Max Depth: 20.075 m / 65.86 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP10.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50862 Long: -122.60761 Undefined SandsVery Stiff Fine GrainedSand MixturesSand Mixtures Sands SandsSilt Mixtures Silt Mixtures Sand Mixtures Silt MixturesSilt MixturesSilt MixturesSand Mixtures Sand MixturesSands Silt MixturesSand Mixtures Sand MixturesSand MixturesSilt MixturesSands Stiff Sand to Clayey SandSand Mixtures Stiff Sand to Clayey Sand Sand Mixtures Silt Mixtures Sand Mixtures Sands Sand Mixtures Sands Sand MixturesSandsSand Mixtures Sand Mixtures Undefined 3.7 30.4 59.5 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched Job No:21-59-21870 Client:PanGEO Project:Anacortes MJB Shoreline Start Date:01-Feb-2021 End Date:01-Feb-2021 CPTu PORE PRESSURE DISSIPATION SUMMARY Sounding ID File Name Cone Area (cm2) Duration (s) Test Depth (ft) Estimated Equilibrium Pore Pressure Ueq (ft) Calculated Phreatic Surface (ft) Estimated Phreatic Surface (ft) t50 1 (s) Assumed Rigidity Index Value (Ir) ch 2 (cm2/min) CPT-1 21-59-21870_CP01.ppd2 15 430 41.7 35.3 6.4 CPT-1 21-59-21870_CP01.ppd2 15 155 45.1 CPT-1 21-59-21870_CP01.ppd2 15 100 52.2 CPT-1 21-59-21870_CP01.ppd2 15 46 59.0 CPT-1 21-59-21870_CP01.ppd2 15 38 64.1 CPT-2 21-59-21870_CP02.ppd2 15 420 8.0 CPT-2 21-59-21870_CP02.ppd2 15 1230 20.0 14.4 5.6 27 100 26.1 CPT-2 21-59-21870_CP02.ppd2 15 50 90.1 CPT-3 21-59-21870_CP03.ppd2 15 7200 10.0 3.6 6.4 1089 100 0.6 CPT-3 21-59-21870_CP03.ppd2 15 38 77.3 CPT-4 21-59-21870_CP04.ppd2 15 300 9.4 3.7 5.6 CPT-4 21-59-21870_CP04.ppd2 15 36 78.9 Total Duration 167.4 min 1. Time is relative to where umax occurred. 2. Houlsby and Teh, 1991. Sheet 1 of 1 0 150 300 450 600 0 50 100 150 200 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 08:31 Site:Anacortes MJB Shoreline Sounding:CPT-1 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP01.ppd2 Depth:12.700 m / 41.666 ft Duration:430.0 s u Min:35.3 ft u Max:164.9 ft u Final:35.3 ft WT: 1.952 m / 6.404 ft Ueq:35.3 ft 0 400 800 1200 1600 0 150 300 450 600 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 09:52 Site:Anacortes MJB Shoreline Sounding:CPT-2 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP02.ppd2 Depth:6.100 m / 20.013 ft Duration:1230.0 s u Min:29.2 ft u Max:533.5 ft u Final:29.2 ft WT: 1.714 m / 5.623 ft Ueq:14.4 ft U(50):273.96 ft T(50):26.9 s Ir:100 Ch:26.1 cm²/min 0 2000 4000 6000 8000 0 75 150 225 300 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 12:06 Site:Anacortes MJB Shoreline Sounding:CPT-3 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP03.ppd2 Depth:3.050 m / 10.006 ft Duration:7200.0 s u Min:20.3 ft u Max:292.2 ft u Final:20.3 ft WT: 1.952 m / 6.404 ft Ueq:3.6 ft U(50):147.93 ft T(50):1088.9 s Ir:100 Ch:0.6 cm²/min 0 100 200 300 400 0.0 3.0 6.0 9.0 0.0 -3.0 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 03:28 Site:Anacortes MJB Shoreline Sounding:CPT-4 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP04.ppd2 Depth:2.850 m / 9.350 ft Duration:300.0 s u Min:-2.5 ft u Max:6.8 ft u Final:3.8 ft WT: 1.714 m / 5.623 ft Ueq:3.7 ft MJB Properties – Anacortes Development Preliminary Infiltration Report CGS Project No. 19057 Prepared for MJB Properties Prepared by Coastal Geologic Services, Inc. Contributors/Authors: Brendan P. Moran, PE November 27, 2019 DR A F T COASTAL GEOLOGIC SERVICES, INC. 1711 Ellis St. Suite 103, Bellingham, WA 98225 (360) 647-1845 www.coastalgeo.com Introduction and Existing Conditions This report presents the results of our Preliminary Infiltration Investigation for the MJB Properties Anacortes Development. The purpose of our investigation was to characterize subsurface conditions and provide preliminary design infiltration rates for the proposed development. The project site is composed of numerous parcels east of Q Avenue roughly between 17th Street and 22nd Street in Anacortes, Washington (See Figure 1, Site Map) totaling approximately 29 acres and including:  Parcel B: P32963  Parcel C: P32965  Parcel D: P32966  Parcel E: P32967  Parcel F: P32968  Parcel G: P32969  Parcel H: P32970  Parcel I: P32971  P32913  P32915  P32916  P32929  P32941  P32943  P78000 The site is bordered on the south by the Anacortes Marina and 22nd Street, on the north by Seafarers Memorial Park and various commercial buildings and paved parking, and on the east by Fidalgo Bay. Most of the subject properties are minimally developed, although extensive shoreline backfilling and dredging has been conducted over a majority of the area. The Northern Marine boat building company operates out of an industrial building in the southwestern portion of the site, close to several other storage and industrial buildings located along a spur of R Avenue. The northeastern portion of the site was previously occupied by Scott Paper Mill, which has since been demolished. We understand that former paper mill operations resulted in soil contamination, and that multiple soil remediation projects have been conducted in the area. Assessment of soil contaminants and associated mitigations are outside the scope of this infiltration investigation. Proposed Construction Based on a conceptual site plan provided by KPFF Consulting Engineers, the proposed construction consists of various multi‐family residences, retail buildings, a hotel and event center, and restaurants with associated paved access drives and parking areas. Potential stormwater management facilities may include raingardens and detention ponds. Based on conversations with project civil engineer Kyle Carrick of KPFF, we understand that captured runoff that cannot be infiltrated will ultimately be discharged to Fidalgo Bay following appropriate water quality control. DR A F T MJB Properties – Anacortes Development – Preliminary Infiltration Report November 27, 2019, p. 2 COASTAL GEOLOGIC SERVICES, INC. Subsurface Exploration and Soil Testing Subsurface conditions were investigated by excavating eight exploratory test pits on November 8, 2019 with a mini‐excavator and operator provided by the client. Test pits were advanced to depths of 7 to 8 FT below ground surface (BGS). Soils generally consisted of 2 to 6.5 FT of fill material overlying very stiff to hard clay and clayey sand interpreted as native glaciomarine drift. The overlying fill material was variously composed of crushed rock top course, construction rubble and debris, and a moderately organic silt/clay that was presumed to be dredged material from historic backfilling at the shoreline. More detailed descriptions of the subsurface conditions encountered in our test pits are provided on our Exploration Logs, Figures A‐1 and A‐2. Geologic Conditions Geologic mapping of the project area was obtained from the Geologic Map of the Bellingham 1:100,000 Quadrangle (Lapen, 2000). The surficial geology of the site is mapped as artificial fill (Qf), concurrent with the surface layer of fill material identified in our test pit explorations. The upland area west of Q Avenue is mapped as glaciomarine drift (Qgdme), described as moderately to unsorted diamicton containing lenses and discontinuous beds of moderately to well‐sorted gravel, sand, silt and clay with variable dropstone content. These soils were deposited 11,300 to 13,500 years ago from melting glacial ice floating in seawater. The low‐energy depositional environment permitted fine particles to settle out of suspension, contributing to clay and silt beds such as those observed during our test pit explorations. Thus, the native soils encountered below the fill in our explorations closely concur with the unit of glaciomarine drift that is mapped adjacent to the site. Groundwater Slight to moderate groundwater seeps were observed in five of the eight test pit explorations at depths of approximately 2.75 to 3.25 FT BGS. The observed seepage was identified as lateral movement of water atop stratigraphic contacts with finer‐grained, denser, lower‐permeability soil, and thus reflects a “perched” water condition rather than a true regional groundwater aquifer at this depth. Nonetheless, seasonal perched groundwater may affect infiltration facilities and will likely be encountered during excavations at this site. Groundwater levels are influenced by seasonal variations in precipitation, changes in runoff patterns due to development and other factors. The groundwater levels recorded on our exploration logs are representative of the time and location of each exploration, and may not be representative of conditions at other times and locations. Results and Discussion Infiltration The 2019 Stormwater Management Manual for Western Washington (SWMMWW) provides Site Suitability Criteria (SSC) for siting infiltration facilities. SSC‐6 indicates that uncontrolled fill materials are unsuitable as infiltration media. Thus, infiltration facilities at this site will be required to bottom into native soils. The SWMMWW provides a methodology for estimating infiltration rates based on the grain‐size distribution of the infiltration soils. This methodology assumes a relatively loose soil consistency and does not account for stiff/dense, compact in‐situ soil conditions such as those observed in the native DR A F T MJB Properties – Anacortes Development – Preliminary Infiltration Report November 27, 2019, p. 3 COASTAL GEOLOGIC SERVICES, INC. glaciomarine drift at this site. Thus, the grain‐size distribution method would not be suitable for estimating a design infiltration rate at this site. Due to the relatively stiff consistency and fine‐grained particle size, it is our opinion that the native glaciomarine drift is effectively impervious and not suitable for infiltration. The presence of shallow, perched groundwater seeps reinforces this assessment. We recommend that stormwater runoff at this site be properly detained, treated, and discharged to an applicable storm sewer system, Fidalgo Bay, or another appropriate outfall as specified by the project civil engineer. Stormwater Treatment For BMPs that will use native soil to provide runoff treatment, SSC‐6 of the SWMMWW specifies a minimum cation exchange capacity (CEC) of 5 meq/100 grams and minimum organic content of 1.0 percent. Three samples of the native glaciomarine drift were sent to Northwest Agricultural Consultants for testing. Results are summarized in Table I below. Table 1. CEC/OC test results. Sample Organic Content Cation Exchange Capacity (meq/100g) TP-1 @ 4 FT 1.65% 17.8 TP-3 @ 5 FT 2.20% 21.0 TP-7 @ 2.5 FT 2.17% 23.7 Based on the test results and minimum requirements of SSC‐6, the native glaciomarine drift soils are suitable for reuse as filtration media in stormwater treatment BMPs. Limitations of This Report This report was prepared for the specific conditions present at the subject property to meet the needs of specific individuals. No one other than the landowner and their agents should apply this report for any purposes other than that originally contemplated without first conferring with the geologist or geotechnical engineer that prepared this report. The findings and recommendations presented in this report were reached based on site visits and subsurface exploration with visual assessment of site soils. Conditions may change at the site due to human influences, floods, groundwater changes, or other factors. This report may not be all that is required to carry out recommended actions. More detailed design specifications may be needed for proper design of potential infiltration facilities or drainage features. We appreciate the opportunity to work with you on this project. Please do not hesitate to contact us with any questions or concerns. References Lapen, TJ. 2000. Geologic Map of the Bellingham 1:100,000 Quadrangle, Washington. Washington State Department of Natural Resources. OFR 2000‐5. Washington State Department of Ecology. July 2019. Stormwater Management Manual for Western Washington. Publication Number 19‐10‐021. DR A F T MJB Properties – Anacortes Development – Preliminary Infiltration Report November 27, 2019, p. 4 COASTAL GEOLOGIC SERVICES, INC. Coastal Geologic Services Inc. DRAFT Brendan P. Moran, PE Geotechnical Engineer ATTACHMENTS:  Figure 1 – Site Map  Figures A‐1 and A‐2 – Exploration Logs DR A F T TP-7 TP-8 TP-6 TP-5 TP-4 TP-3 TP-1 TP-2 Historic Shoreline per Washington DoE Coastal Zone Atlas Conceptual site plan provided by KPFF consulting engineers LEGEND Approximate location of Test Pit exploration TP-1 0200'100' 200' 400' 1"=200' R: \ S k a g i t C o u n t y \ M J B P r o p e r t i e s An a c o r t e s \ G e o t e c h \ F i g u r e s \ M J B A n a c o r t e s L o g s COASTAL GEOLOGIC SERVICES 1711 Ellis St, Suite 103 Bellingham, WA 98225 360-647-1845 - coastalgeo.com Figure # N Client:MJB Properties CGS Project No. 19057 Date: 11/27/2019 1SITE AND EXPLORATION PLAN MJB ANACORTES DEVELOPMENT INFILTRATION INVESTIGATION DR A F T TP-1 Terminal Depth - 7 ft No groundwater seepage observed 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM USCS Depth (ft) SC CL SAND, GRAVEL, COBBLE; relatively clean to silty with depth, angular, slightly moist, dark brown to gray, dense (Fill) Description SAND; very clayey/silty, wet, gray-brown, medium dense (Glaciomarine Drift) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) TP-2 Terminal Depth - 7 ft Moderate groundwater seep @ 3 ft 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM USCS Depth (ft) CL/ FILL SC SAND, GRAVEL, COBBLE; angular boulders in upper 2 ft, relatively clean to silty with depth, angular, dry to moist with depth, gray to red-gray, dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) SAND; very clayey/silty, wet, gray-brown, medium dense (Glaciomarine Drift) TP-3 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-4 Terminal Depth - 7 ft No groundwater seepage observed 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM USCS Depth (ft) GC/ FILL GP/ FILL SAND & GRAVEL; clayey, scattered wood and organics, moist, gray, dense (Fill) Description CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift)Terminal Depth - 7 ft Moderate groundwater seep @ 3 ft USCS GP/GM FILL CL/ FILL CL SAND, GRAVEL, COBBLE; relatively clean to silty with depth, angular, dry to moist with depth, gray to red-gray, dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) GP/GM FILL GP/GM FILL GRAVEL; sandy, angular, scattered rootlets in upper 6 inches, scattered brick/concrete/ rubble throughout, brown to gray, slightly moist, dense (Fill) CL R: \ S k a g i t C o u n t y \ M J B P r o p e r t i e s An a c o r t e s \ G e o t e c h \ F i g u r e s \ M J B A n a c o r t e s L o g s COASTAL GEOLOGIC SERVICES 1711 Ellis St, Suite 103 Bellingham, WA 98225 360-647-1845 - coastalgeo.com Figure # A-1 Client:MJB Properties CGS Project No. 19057 Date: 11/27/2019 EXPLORATION LOGS MJB ANACORTES DEVELOPMENT INFILTRATION INVESTIGATION DR A F T TP-5 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-6 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-7 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-8 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) Terminal Depth - 7.5 ft Slight groundwater seep @ 3 ft USCS GP/ FILL CL/ FILL SAND, GRAVEL, COBBLE; relatively clean, dry to moist with depth, gray, medium dense to dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) CL Terminal Depth - 7.5 ft Slight groundwater seep @ 3.25 ft USCS GP/ FILL CL/ FILL SAND, GRAVEL, COBBLE; rounded, relatively clean, scattered wood and organics, moist, gray, dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) CL Terminal Depth - 8 ft No groundwater seepage observed USCS CL SAND, GRAVEL, COBBLE; angular, silty, moist, gray to brown, very dense (Fill) Description CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) GP/GM FILL Terminal Depth - 8 ft Very slight groundwater seep @ 2.75 ft USCS CL SAND, GRAVEL, COBBLE; angular, silty, moist, gray to brown, very dense (Fill) Description CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) GP/GM FILL R: \ S k a g i t C o u n t y \ M J B P r o p e r t i e s An a c o r t e s \ G e o t e c h \ F i g u r e s \ M J B A n a c o r t e s L o g s COASTAL GEOLOGIC SERVICES 1711 Ellis St, Suite 103 Bellingham, WA 98225 360-647-1845 - coastalgeo.com Figure #Client: MJB Properties CGS Project No. 19057 Date: 11/27/2019 EXPLORATION LOGS MJB ANACORTES DEVELOPMENT INFILTRATION INVESTIGATION A-2 DR A F T 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. We propose to provide this information in a deferred submittal. Bathroom Rough Grading –MJB Properties Appendix 3 DEFERRED SUBMITTAL: PROVIDE A TEST REPORT FROM SOILS SUPPLIER TO THE ENGINEERING DEPT. PROJECT INFORMATION “Model Soil Management Plan for BMP T5.13” age # ____ of ____ pages Complete all information on page 1; only site address and permit number on additional pages. Site Address / Lot No.:______________________________________________________________________________ Permit Type: Permit Number: Permit Holder: Phone: Mailing Address:__________________________________________________________________________________ Contact Person: Phone: Plan Prepared By: 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 proposed 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 ___ Subsoil will be scarified ___ inches (depth) of scarification needed to achieve finished total 12” loosened depth. PRE-APPROVED AMENDMENT METHOD: ___ Topsoil import ___ Amend with compost ___ Stockpile and amend ( ____ cu. yds. stockpiled) ____inches of compost or imported topsoil applied X 3.1 (conversion factor, inches to cubic yards) _____= cu. yards per 1,000 sq. ft. X ___ ,000s sq.ft. in this area ____ = cubic yards of amendment → → → → → (needed to cover this area to designated depth) PRODUCT:_________________________ __________________________________ QUANTITY:________CU. YDS. CUSTOM AMENDMENT ___ Topsoil import ___ Topsoil & compost lift ___ Amend ___ Stockpile and amend (____ cu. yds. stockpiled) Attach test results and calculations. ____ inches organic matter or topsoil import X 3.1 _____= cu. yards / 1,000 sq. ft. X ___ ,000s sq.ft. in this area ____ = cubic yards of amendment → → → → → PRODUCT:_________________________ __________________________________ QUANTITY:________CU. YDS. MULCH ___ ,000 sq.ft. X 6.2 (conversion, to give 2 inch mulch depth) ____ = cubic yards of mulch → → → → → → PRODUCT:_________________________ QUANTITY:________CU. YDS. TOTAL AMENDMENT/TOPSOIL/MULCH FOR ALL AREAS (complete on page 1 only, totaling all areas/pages in this Plan)  Product #1:__________________________________________  Quantity: _________cu. yds.  Test Results: ___ % organic matter ____C:N ratio <25:1 (except mulch, or <35:1 for native plants) ____ “stable” (yes/no)  Product #2:__________________________________________  Quantity: _________cu. yds.  Test Results: ___ % organic matter ____C:N ratio <25:1 (except mulch, or <35:1 for native plants) ____ “stable” (yes/no)  Product #3:__________________________________________  Quantity: _________cu. yds.  Test Results: ___ % organic matter ____C:N ratio <25:1 (except mulch, or <35:1 for native plants) ____ “stable” (yes/no) Date: Inspector: Approved: Revisions Required: Date: Inspector: Approved: Revisions Required: Bathroom Rough Grading –MJB Properties Appendix 4 Appendix 4 Determining Construction Site Sediment Damage Potential Note: See attached. All projects within the City of Anacortes are required to complete that document under Appendix 4. As shown in the included evaluation, the project site has a high potential for sediment transport off the site. August 1, 2013, Modified January 16, 2015 Appendix 7- Determining Sediment Damage Potential Page 1 of 3 Western Washington Phase II 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. ii. STEP 1 – Sediment/Erosion Sensitive Feature Identification 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, II, 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. iii. STEP 2 – Hydraulic Nearness Assessment 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 1, 2013, Modified January 16, 2015 Appendix 7- Determining Sediment Damage Potential Page 2 of 3 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 vi. 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. vii. STEP 3 – Construction Site Sediment Transport Potential 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. August 1, 2013, Modified January 16, 2015 Appendix 7- Determining Sediment Damage Potential Page 3 of 3 Construction Site Sediment Transport Potential Worksheet A. Existing slope of site (average, weighted by aerial extent): Points 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 >5,000 – 10,000 cubic yards ........................................................ 10 >10,000 – 20,000 cubic yards ...................................................... 25 >20,000 cubic yards ..................................................................... 40 D. Runoff potential of predominant soils (Natural Resources Conservation Service): Hydrologic soil group A .................................................................. 0 Hydrologic soil group B ................................................................ 10 Hydrologic soil group C ................................................................ 20 Hydrologic soil group D ............................................................. 40 E. Erosion Potential of predominant soils (Unified Classification System): GW, GP, SW, SP soils ................................................................... 0 Dual classifications (GW-GM, GP-GM, GW-GC, GP-GC, SW-SM, SW-SC, SP-SM, SP-SC) .......................... 10 GM, GC, SM, SC soils.................................................................. 20 ML, CL, MH, CH soils ................................................................... 40 F. Surface or Groundwater entering site identified and intercepted1: Yes ................................................................................................ 0 No ................................................................................................ 25 G. Depth of cut or height of fill >10 feet: Yes .............................................................................................. 25 No .......................................................................................................... 0 H. Clearing and grading will occur in the wet season (October 1 – May 1): Yes .............................................................................................. 50 No .......................................................................................................... 0 TOTAL POINTS.............................................................................................110 1 If no surface or groundwater enters site, give 0 points. Bathroom Rough Grading –MJB Properties Appendix 5 Appendix 5 Site Plan 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com N O T F O R C O N S T R U C T I O N Bathroom Rough Grading –MJB Properties Appendix 6 Appendix 6 Site Photos Aerial Overview Shows current site conditions with homes along R Avenue removed By: Google Maps Bathroom Rough Grading–MJB Properties Appendix 7 Appendix 7 Drainage BMP Facility Maintenance Covenant Not applicable. Bathroom Rough Grading–MJB Properties Appendix 8 Appendix 8 Operation and Maintenance Manual Not applicable. Bathroom Rough Grading–MJB Properties Appendix 9 Appendix 9 Stormwater Pollution Prevention Plan (SWPPP) Copy of approved active SWPPP for the property Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP) for MJB North Roadway and Rough Grading Prepared for: Department of Ecology Northwest Regional Office Permittee / Owner Developer Operator / Contractor MJB Properties LLC Jimmy Blais Gary Merlino Construction Company, Inc. Q Avenue, Anacortes, WA Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number Jimmy Blais MJB Properties LLC 206.255.5153 SWPPP Prepared By Name Organization Contact Phone Number Kyle Carrick KPFF Consutling Engineers 206.926.0737 SWPPP Preparation Date January / 06 / 2021 Project Construction Dates Activity / Phase Start Date End Date MJB North Roadway 05 / 01 / 2021 02 / 31 / 2022 Rough Grading 07/01/2021 09/31/2021 GENERAL INSTRUCTIONS AND CAVEATS This template presents the recommended structure and content for preparation of a Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP). The Department of Ecology’s (Ecology) CSWGP requirements inform the structure and content of this SWPPP template; however, you must customize this template to reflect the conditions of your site. A Construction Stormwater Site Inspection Form can be found on Ecology’s website. https://www.ecology.wa.gov/Regulations-Permits/Permits-certifications/Stormwater-general- permits/Construction-stormwater-permit Using the SWPPP Template Each section will include instructions and space for information specific to your project. Please read the instructions for each section and provide the necessary information when prompted. This Word template can be modified electronically. You may add/delete text, copy and paste, edit tables, etc. Some sections may be completed with brief answers while others may require several pages of explanation. INSTRUCTIONS Instructions are identified by gray shading, and should be deleted upon SWPPP completion. Delete this entire section upon SWPPP completion. Follow this link to a copy of the Construction Stormwater General Permit: https://www.ecology.wa.gov/Regulations-Permits/Permits-certifications/Stormwater-general- permits/Construction-stormwater-permit Table of Contents Project Information (1.0) ................................................................................................................................ 1 Existing Conditions (1.1) ........................................................................................................................... 1 Proposed Construction Activities (1.2) ...................................................................................................... 2 Construction Stormwater Best Management Practices (BMPs) (2.0) ........................................................... 3 The 12 Elements (2.1) ............................................................................................................................... 3 Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1) ............................................................ 3 Element 2: Establish Construction Access (2.1.2) ................................................................................ 4 Element 3: Control Flow Rates (2.1.3) .................................................................................................. 5 Element 4: Install Sediment Controls (2.1.4) ........................................................................................ 6 Element 5: Stabilize Soils (2.1.5) .......................................................................................................... 7 Element 6: Protect Slopes (2.1.6) ......................................................................................................... 8 Element 7: Protect Drain Inlets (2.1.7) .................................................................................................. 9 Element 8: Stabilize Channels and Outlets (2.1.8) ............................................................................. 10 Element 9: Control Pollutants (2.1.9) .................................................................................................. 11 Element 10: Control Dewatering (2.1.10) ............................................................................................ 14 Element 11: Maintain BMPs (2.1.11) .................................................................................................. 15 Element 12: Manage the Project (2.1.12) ........................................................................................... 16 Element 13: Protect Low Impact Development (LID) BMPs (2.1.13).................................................. 19 Monitoring and Sampling Requirements (4.0) ............................................................................................ 20 Site Inspection (4.1) ................................................................................................................................ 20 Stormwater Quality Sampling (4.2) ......................................................................................................... 20 Turbidity Sampling (4.2.1) ................................................................................................................... 20 pH Sampling (4.2.2) ............................................................................................................................ 22 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies (5.0) ........................................ 23 303(d) Listed Waterbodies (5.1) ............................................................................................................. 23 TMDL Waterbodies (5.2) ......................................................................................................................... 23 Reporting and Record Keeping (6.0) .......................................................................................................... 24 Record Keeping (6.1) .............................................................................................................................. 24 Site Log Book (6.1.1) .......................................................................................................................... 24 Records Retention (6.1.2) ................................................................................................................... 24 Updating the SWPPP (6.1.3) .............................................................................................................. 24 Reporting (6.2) ........................................................................................................................................ 25 Discharge Monitoring Reports (6.2.1) ................................................................................................. 25 Notification of Noncompliance (6.2.2) ................................................................................................. 25 List of Tables Table 1 – Summary of Site Pollutant Constituents ....................................... Error! Bookmark not defined. Table 2 – Pollutants .................................................................................................................................... 11 Table 3 – pH-Modifying Sources ................................................................................................................. 12 Table 4 – Dewatering BMPs ....................................................................................................................... 14 Table 5 – Management ............................................................................................................................... 16 Table 6 – BMP Implementation Schedule ................................................................................................... 17 Table 7 – Team Information ........................................................................................................................ 19 Table 8 – Turbidity Sampling Method ......................................................................................................... 20 Table 9 – pH Sampling Method .................................................................................................................. 22 List of Appendices A. TESC Plan B. TESC Details C. Correspondence D. Site Inspection Form E. Construction Stormwater General Permit (CSWGP) G. Contaminated Site Information H. Engineering Calculations List of Acronyms and Abbreviations Acronym / Abbreviation Explanation 303(d) Section of the Clean Water Act pertaining to Impaired Waterbodies BFO Bellingham Field Office of the Department of Ecology BMP(s) Best Management Practice(s) CESCL Certified Erosion and Sediment Control Lead CO2 Carbon Dioxide COA City of Anacortes CRO Central Regional Office of the Department of Ecology CSWGP Construction Stormwater General Permit CWA Clean Water Act DMR Discharge Monitoring Report DO Dissolved Oxygen Ecology Washington State Department of Ecology EPA United States Environmental Protection Agency ERO Eastern Regional Office of the Department of Ecology ERTS Environmental Report Tracking System ESC Erosion and Sediment Control GULD General Use Level Designation NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Units NWRO Northwest Regional Office of the Department of Ecology pH Power of Hydrogen RCW Revised Code of Washington SPCC Spill Prevention, Control, and Countermeasure su Standard Units SWMMEW Stormwater Management Manual for Eastern Washington SWMMWW Stormwater Management Manual for Western Washington SWPPP Stormwater Pollution Prevention Plan TESC Temporary Erosion and Sediment Control SWRO Southwest Regional Office of the Department of Ecology TMDL Total Maximum Daily Load VFO Vancouver Field Office of the Department of Ecology WAC Washington Administrative Code WSDOT Washington Department of Transportation WWHM Western Washington Hydrology Model Page 1 Project Information (1.0) Project/Site Name: MJB North Roadway Street/Location: Q Avenue City: Anacortes State: WA Zip code: 98221 Subdivision: Receiving waterbody: Fidalgo Bay Existing Conditions (1.1) Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage: 27.8 acres Disturbed acreage: 26.6 acres Existing structures: 15 monitoring wells, utilities, fencing, concrete pads, and 5 buildings Landscape topography: The site is currently an undeveloped area with portions of gravel areas, fencing, concrete pads, and an eastern shoreline. The site is generally flat, with isolated steep sections near the eastern shoreline that have steepest slope of approximately 23%. Drainage patterns: Gradually flows from west to east towards Fidalgo Bay. Existing Vegetation: Limited trees and vegetation near the existing buildings Critical Areas (wetlands, streams, high erosion risk, steep or difficult to stabilize slopes): The City of Anacortes and Skagit County classifies the shoreline as a critical area. List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: None known. Page 2 Proposed Construction Activities (1.2) Site development: Phase 1 of site development includes construction of a new roadway and site preparation for a new mixed-use development, to be constructed under a separate permit. The roadway will be constructed first and will extend 17th Street, R Avenue, and 22nd Street/T Avenue right-of- ways. Phase 2 includes clearing and rough grading of the shoreline buffer area to the east of the propsed roadway and west of the ordinary high water mark. Construction activities: Construction activities include installation of erosion control measures, selective site demolition, clearing, excavation, grading, utility construction, and paving. Site drainage (including flow from and onto adjacent properties): A Temporary Erosion and Sediment Control (TESC) Plan is included in Appendix A. For phase 1, runoff will be collected by interceptor swales with rock check dams and routed to a temporary sediment pond to be discharged to Fidalgo Bay. For phase 2, runoff east of the proposed roadway runoff will be collected by interceptor swales with rock check dams and routed to a temporary sediment pond to be discharged to Fidalgo Bay. Site stabilization: All areas disturbed by construction activities will be paved or permanently stabilized with ground cover. Contaminated Site Information: The site was subject to a cleanup action in 2009-2010. On November 2018, the Department of Ecology (Ecology) issued an opinion that no further remedial action would be needed for the site upon completion of the proposed cleanup action. The cleanup has been completed. Page 3 Construction Stormwater Best Management Practices (BMPs) (2.0) The SWPPP is a living document reflecting current conditions and changes throughout the life of the project. These changes may be informal (i.e. hand-written notes and deletions). Update the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design. The 12 Elements (2.1) Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1) The BMP relevant to marking the clearing limits that will be applied for this project include: · BMP C103 Fencing o BMP shall remain in place prior to clearing and staging. BMP shall be maintained throughout the project until the completion of construction. The existing metal fence along the west, north, and southern frontages shall serve as a temporary visibility fence during construction. Contractor to ensure the security and the safety of the public and prevent unauthorized access to the site. To avoid potential erosion and sediment control issues that may cause a violation(s) of the City of Anacortes and Ecology requirements, the Certified Erosion and Sediment Control Lead will inspect the BMP regularly and will promptly make adjustments as necessary if the BMP is ineffective or failing. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 4 Element 2: Establish Construction Access (2.1.2) Construction access or activities occurring on unpaved areas shall be minimized, yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads and Fidalgo Bay. Street sweeping, street cleaning, or wheel wash/tire baths may be necessary if the stabilized construction access is not effective. All washed wastewater shall be controlled on-site. The specific BMPs related to establishing construction access that will be used on this project include: · BMP C105 Stablized Construction Entrance/Exit For phase 1, the construction site will have three stabilized contruction entrances. The access points will be from 17th Street from the west, R Avenue to the north, and 22nd Street/T Avenue from the south. Fot phase 2, the construction site will have one construction entrance from the west at the intersection of T/R Avenue and 17th Street. In addition to the contruction entrances, all existing roadways to be used by construction equipment shall be stabilized if not already. Stablization shall occur on all permanent and temporary surfaces immediately after grading to reduce erosion from both runoff and construction traffic. To avoid potential erosion and sediment control issues that may cause a violation(s) with the City of Anacortes and Ecology requirements, the Certified Erosion and Sediment Control Lead will inspect the BMP regularly and promptly make adjustments as necessary if the BMP is ineffective or failing. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 5 Element 3: Control Flow Rates (2.1.3) Will you construct stormwater retention and/or detention facilities? Yes No Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retention, porous pavement) to control flow during construction? Yes No For phase 1, a temporary sediment pond (BMP C241) will discharge to an existing catch basin. Interceptor swales east of T Avenue and north of 17th Street will collect and convey runoff downstream to the sediment pond. For phase 2, a temporary sediment pond will discharge to a new manhole on an existing storm drain outfall to Fidalgo Bay. Interceptor swales above the ordinary high water mark will collect and convey runoff to the sediment pond. The concentrated flows shall be controlled through the use of the following: · BMP C200 Interceptor swale o BMP shall be installed for concentrated flows during construction. BMP shall be monitored once a week and after each runoff-producing rainfall event. Immediately remove sediment from the flow area. Damage caused by construction traffic or other activity shall be repaired before the end of each working day. · BMP C207 Check dam o BMP shall be installed for concentrated flows during construction. BMP shall be monitored once a week and after each runoff-producing rainfall event. Sediment shall be removed when it reaches one half the height of the dam. Damage caused by construction traffic or other activity shall be repaired before the end of each working day Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 6 Element 4: Install Sediment Controls (2.1.4) All stormwater runoff from disturbed areas shall pass through an appropriate sediment removal BMP before leaving the construction site. The specific BMPs to be used for controlling sediment on this project include: · BMP C233 Silt Fence · BMP C235 Straw Wattles · BMP C241 Sediment Pond Perimeter controls where shown on the plans shall be installed along the downslope side of the project to prevent sediment-laden stormwater from flowing off-site. Silt fences reduce the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. Wattles will be used as necessary to help filter water sheet flowing down the slope. Prior to leaving the construction site, stormwater runoff from on-site disturbed areas shall be routed to a temporary sediment pond prior to discharge to Fidalgo Bay. The contractor shall upgrade the SWPPP facilities to account for severe storm events or if the SWPPP facilities are ineffective at preventing turbid water from leaving the site. In addition, sediment will be removed from paved areas in and adjacent to construction work areas manually or by using mechanical sweepers, as needed, to minimize tracking of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. To avoid potential erosion and sediment control issues that may cause a violation(s) with the City of Anacortes and Ecology requirements, the Certified Erosion and Sediment Control Lead will inspect the BMPs regularly and promptly make adjustments as necessary if any BMPs are ineffective or failing. Final stabilization includes removal of all temporary sediment control BMPs. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 7 Element 5: Stabilize Soils (2.1.5) West of the Cascade Mountains Crest Season Dates Number of Days Soils Can be Left Exposed During the Dry Season May 1 – September 30 7 days During the Wet Season October 1 – April 30 2 days Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. Anticipated project dates: Start date: 05/01/2020 End date: 02/31/2021 Will you construct during the wet season? Yes No Generally, temporary and permanent cover measures shall be provided to protect all disturbed soils and soil stockpiles, including faces of cut and fill slopes. All stockpiled soils must be stabilized from erosion, protected with sediment trapping measures, and, where possible, located away from storm drain inlets, waterways, and drainage channels. The amount of soil exposed throughout the life of the project shall be addressed and stabilized immediately when issues arise. The specific BMPs to be used for providing soil protection from erosion include: · BMP C120 Temporary and Permanent Seeding · BMP C121 Mulching · BMP C123 Plastic Covering (Erosion Control Fabrics) Exposed soils shall be seeded throughout construction on disturbed areas that have reached final grade or that have been left unworked for more than 30 days. Mulching shall be used on disturbed areas that require cover measures for less than 30 days, as a cover for seed during the wet season and during the hot summer months. Plastic covering shall be used on disturbed areas and stockpiled soil that require cover for less than 30 days. At final site stabilization, all disturbed areas not otherwise vegetated or stabilized shall be seeded and mulched. Final stabilization means the completion of all soil-disturbing activities at the site and the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (such as pavement, riprap, gabions, or geotextiles), which will prevent erosion. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Page 8 Responsible Staff: TBD Element 6: Protect Slopes (2.1.6) Will steep slopes be present at the site during construction? Yes No All cut and fill slopes shall be designed, constructed, and protected in a manner that minimizes erosion. No hydrologic analysis is included because there are no pipe drains anticipated to be required. The following specific BMPs will be used to protect slopes for this project: · BMP C200 Interceptor Swale · BMP C207 Check Dam · BMP C121 Seeding/Mulching · BMP C235 Straw Wattles BMPs shall be implemented at the end of each working day when exposed soils and stockpiled materials exist on the project site. BMPs shall be maintained daily to remain in accordance with specifications until the completion of construction. Interceptor swales and check dams shall be used where runoff from disturbed slopes must be conveyed to an erosion control facility and where clean runoff from undisturbed areas must bypass the disturbed areas. Interceptor swales shall direct runoff away from slopes and along a constructed channel to reduce erosion potential, while check dams reduce the velocity of the runoff flowing on the site. To avoid potential erosion and sediment control issues that may cause a violation(s) with the City of Anacortes and Ecology requirements, the Certified Erosion and Sediment Control Lead will inspect the BMPs regularly and promptly make adjustments as necessary if any BMPs are ineffective or failing. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 9 Element 7: Protect Drain Inlets (2.1.7) All storm drain inlets and catch basins shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. Storm drain inlet protection will be implemented for all drainage inlets that could potentially be impacted by sediment-laden runoff on and near the project site. · BMP C220 Storm Drain Inlet Protection Storm drain inlet protection will be installed in all existing and new catch basins during construction to prevent sediment-laden runoff from entering the drainage system. Inlets will be inspected weekly at a minimum and daily during storm events. Cleaning catch basins and inlets along with street sweeping will be performed as additional BMP measures to the catch basin insert installation. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 10 Element 8: Stabilize Channels and Outlets (2.1.8) Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes, and downstream reaches, will be installed at the outlets of all conveyance systems. · BMP C122 Nets/blankets The BMP may be used in the interceptor swale to help stabilize the temporary channel and outlet. On-site interceptor swale channels must handle the peak flow rate from a Type 1A, 10-year, 24- hour frequency storm for the developed condition. The 10-year, 1-hour flow rate predicted by the Western Washington Hydraulic Model (WWHM), increased by a factor of 1.6, may be used. Bare soils were assumed to be modeled as “landscaped area.” See Appendix H for confirmation that the interceptor swales have sufficient capacity. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 11 Element 9: Control Pollutants (2.1.9) The following pollutants are anticipated to be present on-site: Table 1 – Pollutants Pollutant (and source, if applicable) Diesel Fuel – Source is various Hydraulic Fluid – Source is various Concrete and Concrete Slurry – pavement improvements Demolition: · Dust released from demolished sidewalks and walls will be controlled using Dust Control (BMP C140) measures. · Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or debris will be protected using Storm Drain Inlet Protection (as described above for Element 7). · Process water and slurry resulting from sawcutting and surfacing operations will be prevented from entering the waters of the State by implementing Sawcutting and Surfacing Pollution Prevention measures (BMP C152). All pollutants, including waste materials and demolition debris, that occur on-site shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good housekeeping and preventative measures shall be taken to ensure that the site will be kept clean, well organized, and free of debris. If required, BMPs to control specific sources of pollutants are discussed below. In order to perform emergency repairs on-site, temporary plastic will be placed beneath and, if it is raining, over the vehicle. Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Process water and slurry resulting from sawcutting and surfacing operations will be prevented from entering the waters of the State by implementing Sawcutting and Surfacing Pollution Prevention measures. To avoid potential erosion and sediment control issues that may cause a violation(s) with the City of Anacortes and Ecology requirements, the Certified Erosion and Sediment Control Lead will inspect the BMPs regularly and promptly make adjustments as necessary if any BMPs are ineffective or failing. Page 12 Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? Yes No Spill pads and spill kits will be used on-site as needed. Mobile Fuel service will be used. Will wheel wash or tire bath system BMPs be used during construction? Yes No Will pH-modifying sources be present on-site? Yes No If yes, check the source(s). Table 2 – pH-Modifying Sources None X Bulk cement X Cement kiln dust X Fly ash X Other cementitious materials X New concrete washing or curing waters X Waste streams generated from concrete grinding and sawing X Exposed aggregate processes Dewatering concrete vaults Concrete pumping and mixer washout waters Recycled concrete Other (i.e. calcium lignosulfate) [please describe] Concrete and grout: Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling Measures (BMP C151). The pH of stormwater shall be adjusted if outside the range of 6.5 to 8.5 su. Obtain written approval from Ecology before using chemical treatment with the exception of CO2 or dry ice to modify pH. CESCL shall adjust pH of stormwater if monitoring determines that discharge is outside the range of 6.5 to 8.5 su. Page 13 Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches, streets, or streams. Excess concrete must not be dumped on-site, except in designated concrete washout areas with appropriate BMPs installed. Page 14 Element 10: Control Dewatering (2.1.10) Table 3 – Dewatering BMPs Infiltration Transport off-site in a vehicle (vacuum truck for legal disposal) Ecology-approved on-site chemical treatment or other suitable treatment technologies Sanitary or combined sewer discharge with local sewer district approval (last resort) Use of sedimentation bag with discharge to ditch or swale (small volumes of localized dewatering) No BMPs are planned for dewatering for the construction of the roadway. A Geotechnical Report will be performed at a later date to confirm the groundwater table is below planned construction activity. To avoid potential erosion and sediment control issues that may cause a violation(s) with the City of Anacortes and Ecology requirements, the Certified Erosion and Sediment Control Lead will inspect the BMPs regularly and promptly make adjustments as necessary if any BMPs are ineffective or failing. Installation Schedules: BMPs are to be installed prior to the start of construction and will be adjusted as needed to mark the limits of construction. Inspection and Maintenance plan: Inspect and maintain BMPs as required per the Department of Ecology Stormwater Management Manual for Western Washington. Responsible Staff: TBD Page 15 Element 11: Maintain BMPs (2.1.11) All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW). Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be returned to conditions specified in the construction documents. Page 16 Element 12: Manage the Project (2.1.12) The project will be managed based on the following principles: · Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account. · Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Special Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map. Sampling station(s) are located in accordance with applicable requirements of the CSWGP. · Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, S4, and S9 of the CSWGP. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Table 4 – Management X Design the project to fit the existing topography, soils, and drainage patterns X Emphasize erosion control rather than sediment control X Minimize the extent and duration of the area exposed X Keep runoff velocities low X Retain sediment on-site X Thoroughly monitor site and maintain all ESC measures X Schedule major earthwork during the dry season Other (please describe) Page 17 Optional: Fill out Table 6 by listing the BMP associated with specific construction activities. Identify the phase of the project (if applicable). To increase awareness of seasonal requirements, indicate if the activity falls within the wet or dry season. Table 5 – BMP Implementation Schedule Phase of Construction Project Stormwater BMPs Date Wet/Dry Season [Insert construction activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] Page 18 Phase of Construction Project Stormwater BMPs Date Wet/Dry Season [Insert construction activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] Page 19 Element 13: Protect Low Impact Development (LID) BMPs (2.1.13) No LID BMPs are proposed for the project. Pollution Prevention Team (3.0) Table 6 – Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD TBD Resident Engineer TBD TBD Emergency Ecology Contact TBD TBD Emergency Permittee/ Owner Contact TBD TBD Non-Emergency Owner Contact TBD TBD Monitoring Personnel TBD TBD Ecology Regional Office Northwest Regional Office (425) 649-7000 Page 20 Monitoring and Sampling Requirements (4.0) Monitoring includes visual inspection, sampling for water quality parameters of concern, and documentation of the inspection and sampling findings in a site log book. A site log book will be maintained for all on-site construction activities and will include: · A record of the implementation of the SWPPP and other permit requirements · Site inspections · Stormwater sampling data A site inspection is included in Appendix D. The site log book must be maintained on-site within reasonable access to the iste and be made available upon request to Ecology or the local jurisdiction. Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See CSWGP Special Condition S8 and Section 5 of this template. Site Inspection (4.1) Site inspections will be conducted at least once every calendar week and within 24 hours following any discharge from the site. For sites that are temporarily stabilized and inactive, the required frequency is reduced to once per calendar month. The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with the applicable requirements of the CSWGP. Stormwater Quality Sampling (4.2) Turbidity Sampling (4.2.1) Requirements include calibrated turbidity meter or transparency tube to sample site discharges for compliance with the CSWGP. Sampling will be conducted at all discharge points at least once per calendar week. Method for sampling turbidity: Table 7 – Turbidity Sampling Method X Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size) Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size) The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency less than 33 centimeters. Page 21 If the discharge’s turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to or greater than 6 cm, the following steps will be conducted: 1. Review the SWPPP for compliance with Special Condition S9. Make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. 3. Document BMP implementation and maintenance in the site log book. If the turbidity exceeds 250 NTU or the transparency is 6 cm or less at any time, the following steps will be conducted: 1. Telephone or submit an electronic report to the applicable Ecology Region’s Environmental Report Tracking System (ERTS) within 24 hours. https://www.ecology.wa.gov/About-us/Get-involved/Report-an-environmental-issue o Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish, Whatcom): (425) 649-7000 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period 3. Document BMP implementation and maintenance in the site log book. 4. Continue to sample discharges daily until one of the following is true: o Turbidity is 25 NTU (or lower). o Transparency is 33 cm (or greater). o Compliance with the water quality limit for turbidity is achieved.  1 - 5 NTU over background turbidity, if background is less than 50 NTU  1% - 10% over background turbidity, if background is 50 NTU or greater o The discharge stops or is eliminated. Page 22 pH Sampling (4.2.2) pH monitoring is required for “Significant concrete work” (i.e. greater than 1000 cubic yards poured concrete or recycled concrete over the life of the project).The use of engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD] or fly ash) also requires pH monitoring. For significant concrete work, pH sampling will start the first day concrete is poured and continue until it is cured, typically three (3) weeks after the last pour. For engineered soils and recycled concrete, pH sampling begins when engineered soils or recycled concrete are first exposed to precipitation and continues until the area is fully stabilized. If the measured pH is 8.5 or greater, the following measures will be taken: 1. Prevent high pH water from entering storm sewer systems or surface water. 2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate technology such as carbon dioxide (CO2) sparging (liquid or dry ice). 3. Written approval will be obtained from Ecology prior to the use of chemical treatment other than CO2 sparging or dry ice. Method for sampling pH: Table 8 – pH Sampling Method X pH meter pH test kit Wide range pH indicator paper Page 23 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies (5.0) 303(d) Listed Waterbodies (5.1) Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? Yes No List the impairment(s): N/A TMDL Waterbodies (5.2) Waste Load Allocation for CWSGP discharges: N/A List and describe BMPs: N/A Discharges to TMDL receiving waterbodies will meet in-stream water quality criteria at the point of discharge. Page 24 Reporting and Record Keeping (6.0) Record Keeping (6.1) This section does not need to be filled out. It is a list of reminders for the permittee. Site Log Book (6.1.1) A site log book will be maintained for all on-site construction activities and will include: · A record of the implementation of the SWPPP and other permit requirements · Site inspections · Sample logs Records Retention (6.1.2) Records will be retained during the life of the project and for a minimum of three (3) years following the termination of permit coverage in accordance with Special Condition S5.C of the CSWGP. Permit documentation to be retained on-site: · CSWGP · Permit Coverage Letter · SWPPP · Site Log Book Permit documentation will be provided within 14 days of receipt of a written request from Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP. Updating the SWPPP (6.1.3) The SWPPP will be modified if: · Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. · There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine additional or modified BMPs are necessary for compliance. An updated timeline for BMP implementation will be prepared. Page 25 Reporting (6.2) Discharge Monitoring Reports (6.2.1) Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period the DMR will be submitted as required, reporting “No Discharge”. The DMR due date is fifteen (15) days following the end of each calendar month. DMRs will be reported online through Ecology’s WQWebDMR System. To sign up for WQWebDMR go to: https://www.ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Water-quality- permits-guidance/WQWebPortal-guidance Notification of Noncompliance (6.2.2) If any of the terms and conditions of the permit is not met, and the resulting noncompliance may cause a threat to human health or the environment, the following actions will be taken: 1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (Regional office numbers listed below). 2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or correct the noncompliance. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. Specific information to be included in the noncompliance report is found in Special Condition S5.F.3 of the CSWGP. Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6 cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as required by Special Condition S5.A of the CSWGP. · Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, or Yakima County · Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman County · Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit, Snohomish, or Whatcom County · Southwest Region at (360) 407-6300 for Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum Include the following information: Page 26 1. Your name and / Phone number 2. Permit number 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. Page 27 Appendix/Glossary A. TESC Plan B. Correspondence C. Site Inspection Form D. Construction Stormwater General Permit (CSWGP) E. Contaminated Site Information Administrative Order Sanitary Discharge Permit Soil Management Plan Soil and Groundwater Reports Maps and Figures Depicting Contamination F. Engineering Calculations Appendix A TESC Plans (REFER TO CLEARING AND GRADING PERMIT PLANS AND SHORELINE SUBSTANTIAL DEVELOPMENT PERMIT PLANS) Appendix B TESC Details (REFER TO CLEARING AND GRADING PERMIT PLANS AND SHORELINE SUBSTANTIAL DEVELOPMENT PERMIT PLAN) Appendix C Correspondence No direct correspondence has been conducted. Appendix D Site Inspection Form Construction Stormwater Site Inspection Form Page 1 Project Name Permit # Inspection Date Time Name of Certified Erosion Sediment Control Lead (CESCL) or qualified inspector if less than one acre Print Name: Approximate rainfall amount since the last inspection (in inches): Approximate rainfall amount in the last 24 hours (in inches): Current Weather Clear Cloudy Mist Rain Wind Fog A. Type of inspection: Weekly Post Storm Event Other B. Phase of Active Construction (check all that apply): Pre Construction/installation of erosion/sediment controls Clearing/Demo/Grading Infrastructure/storm/roads Concrete pours Vertical Construction/buildings Utilities Offsite improvements Site temporary stabilized Final stabilization C. Questions: 1. Were all areas of construction and discharge points inspected? Yes No 2. Did you observe the presence of suspended sediment, turbidity, discoloration, or oil sheen Yes No 3. Was a water quality sample taken during inspection? (refer to permit conditions S4 & S5) Yes No 4. Was there a turbid discharge 250 NTU or greater, or Transparency 6 cm or less?* Yes No 5. If yes to #4 was it reported to Ecology? Yes No 6. Is pH sampling required? pH range required is 6.5 to 8.5. Yes No If answering yes to a discharge, describe the event. Include when, where, and why it happened; what action was taken, and when. *If answering yes to # 4 record NTU/Transparency with continual sampling daily until turbidity is 25 NTU or less/ transparency is 33 cm or greater. Sampling Results: Date: Parameter Method (circle one) Result Other/Note NTU cm pH Turbidity tube, meter, laboratory pH Paper, kit, meter Construction Stormwater Site Inspection Form Page 2 D. Check the observed status of all items. Provide “Action Required “details and dates. Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 1 Clearing Limits Before beginning land disturbing activities are all clearing limits, natural resource areas (streams, wetlands, buffers, trees) protected with barriers or similar BMPs? (high visibility recommended) 2 Construction Access Construction access is stabilized with quarry spalls or equivalent BMP to prevent sediment from being tracked onto roads? Sediment tracked onto the road way was cleaned thoroughly at the end of the day or more frequent as necessary. 3 Control Flow Rates Are flow control measures installed to control stormwater volumes and velocity during construction and do they protect downstream properties and waterways from erosion? If permanent infiltration ponds are used for flow control during construction, are they protected from siltation? 4 Sediment Controls All perimeter sediment controls (e.g. silt fence, wattles, compost socks, berms, etc.) installed, and maintained in accordance with the Stormwater Pollution Prevention Plan (SWPPP). Sediment control BMPs (sediment ponds, traps, filters etc.) have been constructed and functional as the first step of grading. Stormwater runoff from disturbed areas is directed to sediment removal BMP. 5 Stabilize Soils Have exposed un-worked soils been stabilized with effective BMP to prevent erosion and sediment deposition? Construction Stormwater Site Inspection Form Page 3 Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 5 Stabilize Soils Cont. Are stockpiles stabilized from erosion, protected with sediment trapping measures and located away from drain inlet, waterways, and drainage channels? Have soils been stabilized at the end of the shift, before a holiday or weekend if needed based on the weather forecast? 6 Protect Slopes Has stormwater and ground water been diverted away from slopes and disturbed areas with interceptor dikes, pipes and or swales? Is off-site storm water managed separately from stormwater generated on the site? Is excavated material placed on uphill side of trenches consistent with safety and space considerations? Have check dams been placed at regular intervals within constructed channels that are cut down a slope? 7 Drain Inlets Storm drain inlets made operable during construction are protected. Are existing storm drains within the influence of the project protected? 8 Stabilize Channel and Outlets Have all on-site conveyance channels been designed, constructed and stabilized to prevent erosion from expected peak flows? Is stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes and downstream conveyance systems? 9 Control Pollutants Are waste materials and demolition debris handled and disposed of to prevent contamination of stormwater? Has cover been provided for all chemicals, liquid products, petroleum products, and other material? Has secondary containment been provided capable of containing 110% of the volume? Were contaminated surfaces cleaned immediately after a spill incident? Were BMPs used to prevent contamination of stormwater by a pH modifying sources? Construction Stormwater Site Inspection Form Page 4 Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 9 Cont. Wheel wash wastewater is handled and disposed of properly. 10 Control Dewatering Concrete washout in designated areas. No washout or excess concrete on the ground. Dewatering has been done to an approved source and in compliance with the SWPPP. Were there any clean non turbid dewatering discharges? 11 Maintain BMP Are all temporary and permanent erosion and sediment control BMPs maintained to perform as intended? 12 Manage the Project Has the project been phased to the maximum degree practicable? Has regular inspection, monitoring and maintenance been performed as required by the permit? Has the SWPPP been updated, implemented and records maintained? 13 Protect LID Is all Bioretention and Rain Garden Facilities protected from sedimentation with appropriate BMPs? Is the Bioretention and Rain Garden protected against over compaction of construction equipment and foot traffic to retain its infiltration capabilities? Permeable pavements are clean and free of sediment and sediment laden- water runoff. Muddy construction equipment has not been on the base material or pavement. Have soiled permeable pavements been cleaned of sediments and pass infiltration test as required by stormwater manual methodology? Heavy equipment has been kept off existing soils under LID facilities to retain infiltration rate. E. Check all areas that have been inspected. All in place BMPs All disturbed soils All concrete wash out area All material storage areas All discharge locations All equipment storage areas All construction entrances/exits Construction Stormwater Site Inspection Form Page 5 F. Elements checked “Action Required” (section D) describe corrective action to be taken. List the element number; be specific on location and work needed. Document, initial, and date when the corrective action has been completed and inspected. Element # Description and Location Action Required Completion Date Initials Attach additional page if needed Sign the following certification: “I certify that this report is true, accurate, and complete, to the best of my knowledge and belief” Inspected by: (print) (Signature) Date: Title/Qualification of Inspector: Appendix E CSWGP Issuance Date: Effective Date: Expiration Date: November 18, 2015 January I, 2016 December 31, 2020 Modification Issuance Date: March 22, 2017 Modification Effective Date: May 5, 2017 CONSTRUCTION STORMW ATER GENERAL PERMIT National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit for Stormwater Discharges Associated with Construction Activity State of Washington Department of Ecology Olympia, Washington 98504 In compliance with the provisions of Chapter 90.48 Revised Code of Washington (State of Washington Water Pollution Control Act) and Title 33 United States Code, Section 1251 et seq. The Federal Water Pollution Control Act (The Clean Water Act) Until this permit expires, is modified, or revoked, Permittees that have properly obtained coverage under this general permit are authorized to discharge in accordance with the special and general conditions that follow. her R. Bartlett Wa r Quality Program Manager Washington State Department of Ecology Construction Stormwater General Permit Page 2 TABLE OF CONTENTS LIST OF TABLES ...........................................................................................................................3 SUMMARY OF PERMIT REPORT SUBMITTALS .....................................................................4 SPECIAL CONDITIONS ................................................................................................................5 S1. PERMIT COVERAGE ........................................................................................................5 S2. APPLICATION REQUIREMENTS ...................................................................................8 S3. COMPLIANCE WITH STANDARDS .............................................................................12 S4. MONITORING REQUIREMENTS, BENCHMARKS, AND REPORTING TRIGGERS ................................................................................................13 S5. REPORTING AND RECORDKEEPING REQUIREMENTS .........................................20 S6. PERMIT FEES...................................................................................................................23 S7. SOLID AND LIQUID WASTE DISPOSAL ....................................................................23 S8. DISCHARGES TO 303(d) OR TMDL WATERBODIES ................................................23 S9. STORMWATER POLLUTION PREVENTION PLAN...................................................27 S10. NOTICE OF TERMINATION .........................................................................................37 GENERAL CONDITIONS ...........................................................................................................38 G1. DISCHARGE VIOLATIONS ...........................................................................................38 G2. SIGNATORY REQUIREMENTS.....................................................................................38 G3. RIGHT OF INSPECTION AND ENTRY .........................................................................39 G4. GENERAL PERMIT MODIFICATION AND REVOCATION ......................................39 G5. REVOCATION OF COVERAGE UNDER THE PERMIT .............................................39 G6. REPORTING A CAUSE FOR MODIFICATION ............................................................40 G7. COMPLIANCE WITH OTHER LAWS AND STATUTES .............................................40 G8. DUTY TO REAPPLY .......................................................................................................40 G9. TRANSFER OF GENERAL PERMIT COVERAGE .......................................................41 G10. REMOVED SUBSTANCES .............................................................................................41 G11. DUTY TO PROVIDE INFORMATION ...........................................................................41 G12. OTHER REQUIREMENTS OF 40 CFR ...........................................................................41 G13. ADDITIONAL MONITORING ........................................................................................41 G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS .............................................41 G15. UPSET ...............................................................................................................................42 G16. PROPERTY RIGHTS ........................................................................................................42 Construction Stormwater General Permit Page 3 G17. DUTY TO COMPLY ........................................................................................................42 G18. TOXIC POLLUTANTS.....................................................................................................42 G19. PENALTIES FOR TAMPERING .....................................................................................43 G20. REPORTING PLANNED CHANGES .............................................................................43 G21. REPORTING OTHER INFORMATION ..........................................................................43 G22. REPORTING ANTICIPATED NON-COMPLIANCE .....................................................43 G23. REQUESTS TO BE EXCLUDED FROM COVERAGE UNDER THE PERMIT ..........44 G24. APPEALS ..........................................................................................................................44 G25. SEVERABILITY ...............................................................................................................44 G26. BYPASS PROHIBITED ....................................................................................................44 APPENDIX A – DEFINITIONS ...................................................................................................47 APPENDIX B – ACRONYMS .....................................................................................................55 LIST OF TABLES Table 1: Summary of Required Submittals ................................................................................... 4 Table 2: Summary of Required On-site Documentation............................................................... 4 Table 3: Summary of Primary Monitoring Requirements .......................................................... 15 Table 4: Monitoring and Reporting Requirements ..................................................................... 17 Table 5: Turbidity, Fine Sediment & Phosphorus Sampling and Limits for 303(d)-Listed Waters .................................................................................................... 25 Table 6: pH Sampling and Limits for 303(d)-Listed Waters ...................................................... 26 Construction Stormwater General Permit Page 4 SUMMARY OF PERMIT REPORT SUBMITTALS Refer to the Special and General Conditions within this permit for additional submittal requirements. Appendix A provides a list of definitions. Appendix B provides a list of acronyms. Table 1: Summary of Required Submittals Permit Section Submittal Frequency First Submittal Date S5.A and S8 High Turbidity/Transparency Phone Reporting As Necessary Within 24 hours S5.B Discharge Monitoring Report Monthly* Within 15 days following the end of each month S5.F and S8 Noncompliance Notification – Telephone Notification As necessary Within 24-hours S5.F Noncompliance Notification – Written Report As necessary Within 5 Days of non- compliance S9.C Request for Chemical Treatment Form As necessary Written approval from Ecology is required prior to using chemical treatment (with the exception of dry ice or CO2 to adjust pH) G2 Notice of Change in Authorization As necessary G6 Permit Application for Substantive Changes to the Discharge As necessary G8 Application for Permit Renewal 1/permit cycle No later than 180 days before expiration G9 Notice of Permit Transfer As necessary G20 Notice of Planned Changes As necessary G22 Reporting Anticipated Non- compliance As necessary SPECIAL NOTE: *Permittees must submit electronic Discharge Monitoring Reports (DMRs) to the Washington State Department of Ecology monthly, regardless of site discharge, for the full duration of permit coverage. Refer to Section S5.B of this General Permit for more specific information regarding DMRs. Table 2: Summary of Required On-site Documentation Document Title Permit Conditions Permit Coverage Letter See Conditions S2, S5 Construction Stormwater General Permit See Conditions S2, S5 Site Log Book See Conditions S4, S5 Stormwater Pollution Prevention Plan (SWPPP) See Conditions S9, S5 Construction Stormwater General Permit Page 5 SPECIAL CONDITIONS S1. PERMIT COVERAGE A. Permit Area This Construction Stormwater General Permit (CSWGP) covers all areas of Washington State, except for federal operators and Indian Country as specified in Special Condition S1.E.3. B. Operators Required to Seek Coverage Under this General Permit: 1. Operators of the following construction activities are required to seek coverage under this CSWGP: a. Clearing, grading and/or excavation that results in the disturbance of one or more acres (including off-site disturbance acreage authorized in S1.C.2) and discharges stormwater to surface waters of the State; and clearing, grading and/or excavation on sites smaller than one acre that are part of a larger common plan of development or sale, if the common plan of development or sale will ultimately disturb one acre or more and discharge stormwater to surface waters of the State. i. This includes forest practices (including, but not limited to, class IV conversions) that are part of a construction activity that will result in the disturbance of one or more acres, and discharge to surface waters of the State (that is, forest practices that prepare a site for construction activities); and b. Any size construction activity discharging stormwater to waters of the State that the Washington State Department of Ecology (Ecology): i. Determines to be a significant contributor of pollutants to waters of the State of Washington. ii. Reasonably expects to cause a violation of any water quality standard. 2. Operators of the following activities are not required to seek coverage under this CSWGP (unless specifically required under Special Condition S1.B.1.b. above): a. Construction activities that discharge all stormwater and non-stormwater to ground water, sanitary sewer, or combined sewer, and have no point source discharge to either surface water or a storm sewer system that drains to surface waters of the State. b. Construction activities covered under an Erosivity Waiver (Special Condition S2.C). c. Routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. Construction Stormwater General Permit Page 6 C. Authorized Discharges: 1. Stormwater Associated with Construction Activity. Subject to compliance with the terms and conditions of this permit, Permittees are authorized to discharge stormwater associated with construction activity to surface waters of the State or to a storm sewer system that drains to surface waters of the State. (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.) 2. Stormwater Associated with Construction Support Activity. This permit also authorizes stormwater discharge from support activities related to the permitted construction site (for example, an on-site portable rock crusher, off-site equipment staging yards, material storage areas, borrow areas, etc.) provided: a. The support activity relates directly to the permitted construction site that is required to have an NPDES permit; and b. The support activity is not a commercial operation serving multiple unrelated construction projects, and does not operate beyond the completion of the construction activity; and c. Appropriate controls and measures are identified in the Stormwater Pollution Prevention Plan (SWPPP) for the discharges from the support activity areas. 3. Non-Stormwater Discharges. The categories and sources of non-stormwater discharges identified below are authorized conditionally, provided the discharge is consistent with the terms and conditions of this permit: a. Discharges from fire-fighting activities. b. Fire hydrant system flushing. c. Potable water, including uncontaminated water line flushing. d. Hydrostatic test water. e. Uncontaminated air conditioning or compressor condensate. f. Uncontaminated ground water or spring water. g. Uncontaminated excavation dewatering water (in accordance with S9.D.10). h. Uncontaminated discharges from foundation or footing drains. i. Uncontaminated or potable water used to control dust. Permittees must minimize the amount of dust control water used. j. Routine external building wash down that does not use detergents. k. Landscape irrigation water. The SWPPP must adequately address all authorized non-stormwater discharges, except for discharges from fire-fighting activities, and must comply with Special Condition S3. Construction Stormwater General Permit Page 7 At a minimum, discharges from potable water (including water line flushing), fire hydrant system flushing, and pipeline hydrostatic test water must undergo the following: dechlorination to a concentration of 0.1 parts per million (ppm) or less, and pH adjustment to within 6.5 – 8.5 standard units (su), if necessary. D. Prohibited Discharges: The following discharges to waters of the State, including ground water, are prohibited. 1. Concrete wastewater. 2. Wastewater from washout and clean-up of stucco, paint, form release oils, curing compounds and other construction materials. 3. Process wastewater as defined by 40 Code of Federal Regulations (CFR) 122.2 (see Appendix A of this permit). 4. Slurry materials and waste from shaft drilling, including process wastewater from shaft drilling for construction of building, road, and bridge foundations unless managed according to Special Condition S9.D.9.j. 5. Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance. 6. Soaps or solvents used in vehicle and equipment washing. 7. Wheel wash wastewater, unless managed according to Special Condition S9.D.9. 8. Discharges from dewatering activities, including discharges from dewatering of trenches and excavations, unless managed according to Special Condition S9.D.10. E. Limits on Coverage Ecology may require any discharger to apply for and obtain coverage under an individual permit or another more specific general permit. Such alternative coverage will be required when Ecology determines that this CSWGP does not provide adequate assurance that water quality will be protected, or there is a reasonable potential for the project to cause or contribute to a violation of water quality standards. The following stormwater discharges are not covered by this permit: 1. Post-construction stormwater discharges that originate from the site after completion of construction activities and the site has undergone final stabilization. 2. Non-point source silvicultural activities such as nursery operations, site preparation, reforestation and subsequent cultural treatment, thinning, prescribed burning, pest and fire control, harvesting operations, surface drainage, or road construction and maintenance, from which there is natural runoff as excluded in 40 CFR Subpart 122. 3. Stormwater from any federal operator. Construction Stormwater General Permit Page 8 4. Stormwater from facilities located on “Indian Country” as defined in 18 U.S.C.§1151, except portions of the Puyallup Reservation as noted below. Indian Country includes: a. All land within any Indian Reservation notwithstanding the issuance of any patent, and, including rights-of-way running through the reservation. This includes all federal, tribal, and Indian and non-Indian privately owned land within the reservation. b. All off-reservation Indian allotments, the Indian titles to which have not been extinguished, including rights-of-way running through the same. c. All off-reservation federal trust lands held for Native American Tribes. Puyallup Exception: Following the Puyallup Tribes of Indians Land Settlement Act of 1989, 25 U.S.C. §1773; the permit does apply to land within the Puyallup Reservation except for discharges to surface water on land held in trust by the federal government. 5. Stormwater from any site covered under an existing NPDES individual permit in which stormwater management and/or treatment requirements are included for all stormwater discharges associated with construction activity. 6. Stormwater from a site where an applicable Total Maximum Daily Load (TMDL) requirement specifically precludes or prohibits discharges from construction activity. S2. APPLICATION REQUIREMENTS A. Permit Application Forms 1. Notice of Intent Form/Timeline a. Operators of new or previously unpermitted construction activities must submit a complete and accurate permit application (Notice of Intent, or NOI) to Ecology. b. Operators must apply using the electronic application form (NOI) available on Ecology’s website http://www.ecy.wa.gov/programs/wq/stormwater/ construction/index.html. Permittees unable to submit electronically (for example, those who do not have an internet connection) must contact Ecology to request a waiver and obtain instructions on how to obtain a paper NOI. Department of Ecology Water Quality Program - Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 Construction Stormwater General Permit Page 9 c. The operator must submit the NOI at least 60 days before discharging stormwater from construction activities and must submit it on or before the date of the first public notice (see Special Condition S2.B below for details). The 30- day public comment period begins on the publication date of the second public notice. Unless Ecology responds to the complete application in writing, based on public comments, or any other relevant factors, coverage under the general permit will automatically commence on the thirty-first day following receipt by Ecology of a completed NOI, or the issuance date of this permit, whichever is later; unless Ecology specifies a later date in writing as required by WAC173- 226-200(2). d. If an applicant intends to use a Best Management Practice (BMP) selected on the basis of Special Condition S9.C.4 (“demonstrably equivalent” BMPs), the applicant must notify Ecology of its selection as part of the NOI. In the event the applicant selects BMPs after submission of the NOI, it must provide notice of the selection of an equivalent BMP to Ecology at least 60 days before intended use of the equivalent BMP. e. Permittees must notify Ecology regarding any changes to the information provided on the NOI by submitting an updated NOI. Examples of such changes include, but are not limited to: i. Changes to the Permittee’s mailing address, ii. Changes to the on-site contact person information, and iii. Changes to the area/acreage affected by construction activity. f. Applicants must notify Ecology if they are aware of contaminated soils and/or groundwater associated with the construction activity. Provide detailed information with the NOI (as known and readily available) on the nature and extent of the contamination (concentrations, locations, and depth), as well as pollution prevention and/or treatment BMPs proposed to control the discharge of soil and/or groundwater contaminants in stormwater. Examples of such detail may include, but are not limited to: i. List or table of all known contaminants with laboratory test results showing concentration and depth, ii. Map with sample locations, iii. Temporary Erosion and Sediment Control (TESC) plans, iv. Related portions of the Stormwater Pollution Prevention Plan (SWPPP) that address the management of contaminated and potentially contaminated construction stormwater and dewatering water, v. Dewatering plan and/or dewatering contingency plan. Construction Stormwater General Permit Page 10 2. Transfer of Coverage Form The Permittee can transfer current coverage under this permit to one or more new operators, including operators of sites within a Common Plan of Development, provided the Permittee submits a Transfer of Coverage Form in accordance with General Condition G9. Transfers do not require public notice. B. Public Notice For new or previously unpermitted construction activities, the applicant must publish a public notice at least one time each week for two consecutive weeks, at least 7 days apart, in a newspaper with general circulation in the county where the construction is to take place. The notice must contain: 1. A statement that “The applicant is seeking coverage under the Washington State Department of Ecology’s Construction Stormwater NPDES and State Waste Discharge General Permit”. 2. The name, address and location of the construction site. 3. The name and address of the applicant. 4. The type of construction activity that will result in a discharge (for example, residential construction, commercial construction, etc.), and the number of acres to be disturbed. 5. The name of the receiving water(s) (that is, the surface water(s) to which the site will discharge), or, if the discharge is through a storm sewer system, the name of the operator of the system. 6. The statement: “Any persons desiring to present their views to the Washington State Department of Ecology regarding this application, or interested in Ecology’s action on this application, may notify Ecology in writing no later than 30 days of the last date of publication of this notice. Ecology reviews public comments and considers whether discharges from this project would cause a measurable change in receiving water quality, and, if so, whether the project is necessary and in the overriding public interest according to Tier II antidegradation requirements under WAC 173-201A-320. Comments can be submitted to: Department of Ecology, PO Box 47696, Olympia, Washington 98504-7696 Attn: Water Quality Program, Construction Stormwater.” Construction Stormwater General Permit Page 11 C. Erosivity Waiver Construction site operators may qualify for an erosivity waiver from the CSWGP if the following conditions are met: 1. The site will result in the disturbance of fewer than 5 acres and the site is not a portion of a common plan of development or sale that will disturb 5 acres or greater. 2. Calculation of Erosivity “R” Factor and Regional Timeframe: a. The project’s rainfall erosivity factor (“R” Factor) must be less than 5 during the period of construction activity, as calculated (see the CSWGP homepage http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html for a link to the EPA’s calculator and step by step instructions on computing the “R” Factor in the EPA Erosivity Waiver Fact Sheet). The period of construction activity starts when the land is first disturbed and ends with final stabilization. In addition: b. The entire period of construction activity must fall within the following timeframes: i. For sites west of the Cascades Crest: June 15 – September 15. ii. For sites east of the Cascades Crest, excluding the Central Basin: June 15 – October 15. iii. For sites east of the Cascades Crest, within the Central Basin: no additional timeframe restrictions apply. The Central Basin is defined as the portions of Eastern Washington with mean annual precipitation of less than 12 inches. For a map of the Central Basin (Average Annual Precipitation Region 2), refer to http://www.ecy.wa.gov/programs/wq/stormwater/ construction/resourcesguidance.html. 3. Construction site operators must submit a complete Erosivity Waiver certification form at least one week before disturbing the land. Certification must include statements that the operator will: a. Comply with applicable local stormwater requirements; and b. Implement appropriate erosion and sediment control BMPs to prevent violations of water quality standards. 4. This waiver is not available for facilities declared significant contributors of pollutants as defined in Special Condition S1.B.1.b. or for any size construction activity that could reasonably expect to cause a violation of any water quality standard as defined in Special Condition S1.B.1.b.ii. 5. This waiver does not apply to construction activities which include non- stormwater discharges listed in Special Condition S1.C.3. Construction Stormwater General Permit Page 12 6. If construction activity extends beyond the certified waiver period for any reason, the operator must either: a. Recalculate the rainfall erosivity “R” factor using the original start date and a new projected ending date and, if the “R” factor is still under 5 and the entire project falls within the applicable regional timeframe in Special Condition S2.C.2.b, complete and submit an amended waiver certification form before the original waiver expires; or b. Submit a complete permit application to Ecology in accordance with Special Condition S2.A and B before the end of the certified waiver period. S3. COMPLIANCE WITH STANDARDS A. Discharges must not cause or contribute to a violation of surface water quality standards (Chapter 173-201A WAC), ground water quality standards (Chapter 173-200 WAC), sediment management standards (Chapter 173-204 WAC), and human health-based criteria in the National Toxics Rule (40 CFR Part 131.36). Discharges not in compliance with these standards are not authorized. B. Prior to the discharge of stormwater and non-stormwater to waters of the State, the Permittee must apply all known, available, and reasonable methods of prevention, control, and treatment (AKART). This includes the preparation and implementation of an adequate SWPPP, with all appropriate BMPs installed and maintained in accordance with the SWPPP and the terms and conditions of this permit. C. Ecology presumes that a Permittee complies with water quality standards unless discharge monitoring data or other site-specific information demonstrates that a discharge causes or contributes to a violation of water quality standards, when the Permittee complies with the following conditions. The Permittee must fully: 1. Comply with all permit conditions, including planning, sampling, monitoring, reporting, and recordkeeping conditions. 2. Implement stormwater BMPs contained in stormwater management manuals published or approved by Ecology, or BMPs that are demonstrably equivalent to BMPs contained in stormwater technical manuals published or approved by Ecology, including the proper selection, implementation, and maintenance of all applicable and appropriate BMPs for on-site pollution control. (For purposes of this section, the stormwater manuals listed in Appendix 10 of the Phase I Municipal Stormwater Permit are approved by Ecology.) D. Where construction sites also discharge to ground water, the ground water discharges must also meet the terms and conditions of this CSWGP. Permittees who discharge to ground water through an injection well must also comply with any applicable requirements of the Underground Injection Control (UIC) regulations, Chapter 173-218 WAC. Construction Stormwater General Permit Page 13 S4. MONITORING REQUIREMENTS, BENCHMARKS AND REPORTING TRIGGERS A. Site Log Book The Permittee must maintain a site log book that contains a record of the implementation of the SWPPP and other permit requirements, including the installation and maintenance of BMPs, site inspections, and stormwater monitoring. B. Site Inspections The Permittee’s site inspections must include all areas disturbed by construction activities, all BMPs, and all stormwater discharge points under the Permittee’s operational control. (See Special Conditions S4.B.3 and B.4 below for detailed requirements of the Permittee’s Certified Erosion and Sediment Control Lead [CESCL].) Construction sites one acre or larger that discharge stormwater to surface waters of the State must have site inspections conducted by a certified CESCL. Sites less than one acre may have a person without CESCL certification conduct inspections. 1. The Permittee must examine stormwater visually for the presence of suspended sediment, turbidity, discoloration, and oil sheen. The Permittee must evaluate the effectiveness of BMPs and determine if it is necessary to install, maintain, or repair BMPs to improve the quality of stormwater discharges. Based on the results of the inspection, the Permittee must correct the problems identified by: a. Reviewing the SWPPP for compliance with Special Condition S9 and making appropriate revisions within 7 days of the inspection. b. Immediately beginning the process of fully implementing and maintaining appropriate source control and/or treatment BMPs as soon as possible, addressing the problems no later than within 10 days of the inspection. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when an extension is requested by a Permittee within the initial 10-day response period. c. Documenting BMP implementation and maintenance in the site log book. 2. The Permittee must inspect all areas disturbed by construction activities, all BMPs, and all stormwater discharge points at least once every calendar week and within 24 hours of any discharge from the site. (For purposes of this condition, individual discharge events that last more than one day do not require daily inspections. For example, if a stormwater pond discharges continuously over the course of a week, only one inspection is required that week.) The Permittee may reduce the inspection frequency for temporarily stabilized, inactive sites to once every calendar month. Construction Stormwater General Permit Page 14 3. The Permittee must have staff knowledgeable in the principles and practices of erosion and sediment control. The CESCL (sites one acre or more) or inspector (sites less than one acre) must have the skills to assess the: a. Site conditions and construction activities that could impact the quality of stormwater, and b. Effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. 4. The SWPPP must identify the CESCL or inspector, who must be present on site or on-call at all times. The CESCL must obtain this certification through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (see BMP C160 in the manual referred to in Special Condition S9.C.1 and 2). 5. The Permittee must summarize the results of each inspection in an inspection report or checklist and enter the report/checklist into, or attach it to, the site log book. At a minimum, each inspection report or checklist must include: a. Inspection date and time. b. Weather information, the general conditions during inspection and the approximate amount of precipitation since the last inspection, and precipitation within the last 24 hours. c. A summary or list of all implemented BMPs, including observations of all erosion/sediment control structures or practices. d. A description of the locations: i. Of BMPs inspected; ii. Of BMPs that need maintenance and why; iii. Of BMPs that failed to operate as designed or intended; and iv. Where additional or different BMPs are needed, and why. e. A description of stormwater discharged from the site. The Permittee must note the presence of suspended sediment, turbidity, discoloration, and oil sheen, as applicable. f. Any water quality monitoring performed during inspection. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made following the inspection. h. A summary report and a schedule of implementation of the remedial actions that the Permittee plans to take if the site inspection indicates that the site is out of compliance. The remedial actions taken must meet the requirements of the SWPPP and the permit. Construction Stormwater General Permit Page 15 i. The name, title, and signature of the person conducting the site inspection, a phone number or other reliable method to reach this person, and the following statement: “I certify that this report is true, accurate, and complete to the best of my knowledge and belief.” Table 3: Summary of Primary Monitoring Requirements Size of Soil Disturbance1 Weekly Site Inspections Weekly Sampling w/ Turbidity Meter Weekly Sampling w/ Transparency Tube Weekly pH Sampling2 CESCL Required for Inspections? Sites that disturb less than 1 acre, but are part of a larger Common Plan of Development Required Not Required Not Required Not Required No Sites that disturb 1 acre or more, but fewer than 5 acres Required Sampling Required – either method3 Required Yes Sites that disturb 5 acres or more Required Required Not Required4 Required Yes 1 Soil disturbance is calculated by adding together all areas that will be affected by construction activity. Construction activity means clearing, grading, excavation, and any other activity that disturbs the surface of the land, including ingress/egress from the site. 2 If construction activity results in the disturbance of 1 acre or more, and involves significant concrete work (1,000 cubic yards of poured concrete or recycled concrete over the life of a project) or the use of engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer stormwater collection system that drains to other surface waters of the State, the Permittee must conduct pH sampling in accordance with Special Condition S4.D. 3 Sites with one or more acres, but fewer than 5 acres of soil disturbance, must conduct turbidity or transparency sampling in accordance with Special Condition S4.C. 4 Sites equal to or greater than 5 acres of soil disturbance must conduct turbidity sampling using a turbidity meter in accordance with Special Condition S4.C. Construction Stormwater General Permit Page 16 C. Turbidity/Transparency Sampling Requirements 1. Sampling Methods a. If construction activity involves the disturbance of 5 acres or more, the Permittee must conduct turbidity sampling per Special Condition S4.C. b. If construction activity involves 1 acre or more but fewer than 5 acres of soil disturbance, the Permittee must conduct either transparency sampling or turbidity sampling per Special Condition S4.C. 2. Sampling Frequency a. The Permittee must sample all discharge points at least once every calendar week when stormwater (or authorized non-stormwater) discharges from the site or enters any on-site surface waters of the state (for example, a creek running through a site); sampling is not required on sites that disturb less than an acre. b. Samples must be representative of the flow and characteristics of the discharge. c. Sampling is not required when there is no discharge during a calendar week. d. Sampling is not required outside of normal working hours or during unsafe conditions. e. If the Permittee is unable to sample during a monitoring period, the Permittee must include a brief explanation in the monthly Discharge Monitoring Report (DMR). f. Sampling is not required before construction activity begins. g. The Permittee may reduce the sampling frequency for temporarily stabilized, inactive sites to once every calendar month. 3. Sampling Locations a. Sampling is required at all points where stormwater associated with construction activity (or authorized non-stormwater) is discharged off site, including where it enters any on-site surface waters of the state (for example, a creek running through a site). b. The Permittee may discontinue sampling at discharge points that drain areas of the project that are fully stabilized to prevent erosion. c. The Permittee must identify all sampling point(s) on the SWPPP site map and clearly mark these points in the field with a flag, tape, stake or other visible marker. d. Sampling is not required for discharge that is sent directly to sanitary or combined sewer systems. Construction Stormwater General Permit Page 17 e. The Permittee may discontinue sampling at discharge points in areas of the project where the Permittee no longer has operational control of the construction activity. 4. Sampling and Analysis Methods a. The Permittee performs turbidity analysis with a calibrated turbidity meter (turbidimeter) either on site or at an accredited lab. The Permittee must record the results in the site log book in nephelometric turbidity units (NTUs). b. The Permittee performs transparency analysis on site with a 1¾-inch-diameter, 60-centimeter (cm)-long transparency tube. The Permittee will record the results in the site log book in centimeters (cm). Table 4: Monitoring and Reporting Requirements Parameter Unit Analytical Method Sampling Frequency Benchmark Value Phone Reporting Trigger Value Turbidity NTU SM2130 Weekly, if discharging 25 NTUs 250 NTUs Transparency cm Manufacturer instructions, or Ecology guidance Weekly, if discharging 33 cm 6 cm 5. Turbidity/Transparency Benchmark Values and Reporting Triggers The benchmark value for turbidity is 25 NTUs or less. The benchmark value for transparency is 33 centimeters (cm). Note: Benchmark values do not apply to discharges to segments of water bodies on Washington State’s 303(d) list (Category 5) for turbidity, fine sediment, or phosphorus; these discharges are subject to a numeric effluent limit for turbidity. Refer to Special Condition S8 for more information. a. Turbidity 26 – 249 NTUs, or Transparency 32 – 7 cm: If the discharge turbidity is 26 to 249 NTUs; or if discharge transparency is less than 33 cm, but equal to or greater than 6 cm, the Permittee must: i. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. ii. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. Construction Stormwater General Permit Page 18 iii. Document BMP implementation and maintenance in the site log book. b. Turbidity 250 NTUs or greater, or Transparency 6 cm or less: If a discharge point’s turbidity is 250 NTUs or greater, or if discharge transparency is less than or equal to 6 cm, the Permittee must complete the reporting and adaptive management process described below. i. Telephone or submit an electronic report to the applicable Ecology Region’s Environmental Report Tracking System (ERTS) number (or through Ecology’s Water Quality Permitting Portal [WQWebPortal] – Permit Submittals when the form is available) within 24 hours, in accordance with Special Condition S5.A.  Central Region (Okanogan, Chelan, Douglas, Kittitas, Yakima, Klickitat, Benton): (509) 575-2490  Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400  Northwest Region (Kitsap, Snohomish, Island, King, San Juan, Skagit, Whatcom): (425) 649-7000  Southwest Region (Grays Harbor, Lewis, Mason, Thurston, Pierce, Clark, Cowlitz, Skamania, Wahkiakum, Clallam, Jefferson, Pacific): (360) 407-6300 Links to these numbers and the ERTS reporting page are located on the following web site: http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html. ii. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. iii. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. iv. Document BMP implementation and maintenance in the site log book. v. Sample discharges daily until: a) Turbidity is 25 NTUs (or lower); or b) Transparency is 33 cm (or greater); or Construction Stormwater General Permit Page 19 c) The Permittee has demonstrated compliance with the water quality limit for turbidity: 1) No more than 5 NTUs over background turbidity, if background is less than 50 NTUs, or 2) No more than 10% over background turbidity, if background is 50 NTUs or greater; or d) The discharge stops or is eliminated. D. pH Sampling Requirements – Significant Concrete Work or Engineered Soils If construction activity results in the disturbance of 1 acre or more, and involves significant concrete work (significant concrete work means greater than 1000 cubic yards poured concrete or recycled concrete used over the life of a project) or the use of engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer system that drains to surface waters of the State, the Permittee must conduct pH sampling as set forth below. Note: In addition, discharges to segments of water bodies on Washington State’s 303(d) list (Category 5) for high pH are subject to a numeric effluent limit for pH; refer to Special Condition S8. 1. For sites with significant concrete work, the Permittee must begin the pH sampling period when the concrete is first poured and exposed to precipitation, and continue weekly throughout and after the concrete pour and curing period, until stormwater pH is in the range of 6.5 to 8.5 (su). 2. For sites with recycled concrete where monitoring is required, the Permittee must begin the weekly pH sampling period when the recycled concrete is first exposed to precipitation and must continue until the recycled concrete is fully stabilized with the stormwater pH in the range of 6.5 to 8.5 (su). 3. For sites with engineered soils, the Permittee must begin the pH sampling period when the soil amendments are first exposed to precipitation and must continue until the area of engineered soils is fully stabilized. 4. During the applicable pH monitoring period defined above, the Permittee must obtain a representative sample of stormwater and conduct pH analysis at least once per week. 5. The Permittee must sample pH in the sediment trap/pond(s) or other locations that receive stormwater runoff from the area of significant concrete work or engineered soils before the stormwater discharges to surface waters. 6. The benchmark value for pH is 8.5 standard units. Anytime sampling indicates that pH is 8.5 or greater, the Permittee must either: Construction Stormwater General Permit Page 20 a. Prevent the high pH water (8.5 or above) from entering storm sewer systems or surface waters; or b. If necessary, adjust or neutralize the high pH water until it is in the range of pH 6.5 to 8.5 (su) using an appropriate treatment BMP such as carbon dioxide (CO2) sparging or dry ice. The Permittee must obtain written approval from Ecology before using any form of chemical treatment other than CO2 sparging or dry ice. 7. The Permittee must perform pH analysis on site with a calibrated pH meter, pH test kit, or wide range pH indicator paper. The Permittee must record pH sampling results in the site log book. S5. REPORTING AND RECORDKEEPING REQUIREMENTS A. High Turbidity Reporting Anytime sampling performed in accordance with Special Condition S4.C indicates turbidity has reached the 250 NTUs or more (or transparency less than or equal to 6 cm) high turbidity reporting level, the Permittee must either call the applicable Ecology Region’s Environmental Report Tracking System (ERTS) number by phone within 24 hours of analysis or submit an electronic ERTS report (or submit an electronic report through Ecology’s Water Quality Permitting Portal (WQWebPortal) – Permit Submittals when the form is available). See the CSWGP web site for links to ERTS and the WQWebPortal: http://www.ecy.wa.gov/programs/wq/stormwater/construction/ index.html. Also, see phone numbers in Special Condition S4.C.5.b.i. B. Discharge Monitoring Reports (DMRs) Permittees required to conduct water quality sampling in accordance with Special Conditions S4.C (Turbidity/Transparency), S4.D (pH), S8 (303[d]/TMDL sampling), and/or G13 (Additional Sampling) must submit the results to Ecology. Permittees must submit monitoring data using Ecology's WQWebDMR web application accessed through Ecology’s Water Quality Permitting Portal. To find out more information and to sign up for WQWebDMR go to: http://www.ecy.wa.gov/programs/ wq/permits/paris/portal.html. Permittees unable to submit electronically (for example, those who do not have an internet connection) must contact Ecology to request a waiver and obtain instructions on how to obtain a paper copy DMR at: Department of Ecology Water Quality Program - Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 Permittees who obtain a waiver not to use WQWebDMR must use the forms provided to them by Ecology; submittals must be mailed to the address above. Permittees shall Construction Stormwater General Permit Page 21 submit DMR forms to be received by Ecology within 15 days following the end of each month. If there was no discharge during a given monitoring period, all Permittees must submit a DMR as required with “no discharge" entered in place of the monitoring results. DMRs are required for the full duration of permit coverage (from issuance date to termination). For more information, contact Ecology staff using information provided at the following web site: www.ecy.wa.gov/programs/wq/permits/paris/contacts.html. C. Records Retention The Permittee must retain records of all monitoring information (site log book, sampling results, inspection reports/checklists, etc.), Stormwater Pollution Prevention Plan, copy of the permit coverage letter (including Transfer of Coverage documentation), and any other documentation of compliance with permit requirements for the entire life of the construction project and for a minimum of three years following the termination of permit coverage. Such information must include all calibration and maintenance records, and records of all data used to complete the application for this permit. This period of retention must be extended during the course of any unresolved litigation regarding the discharge of pollutants by the Permittee or when requested by Ecology. D. Recording Results For each measurement or sample taken, the Permittee must record the following information: 1. Date, place, method, and time of sampling or measurement. 2. The first and last name of the individual who performed the sampling or measurement. 3. The date(s) the analyses were performed. 4. The first and last name of the individual who performed the analyses. 5. The analytical techniques or methods used. 6. The results of all analyses. E. Additional Monitoring by the Permittee If the Permittee monitors any pollutant more frequently than required by this permit using test procedures specified by Special Condition S4 of this permit, the results of this monitoring must be included in the calculation and reporting of the data submitted in the Permittee’s DMR. F. Noncompliance Notification In the event the Permittee is unable to comply with any part of the terms and conditions of this permit, and the resulting noncompliance may cause a threat to human health or the environment (such as but not limited to spills of fuels or other materials, catastrophic pond or slope failure, and discharges that violate water quality standards), or exceed Construction Stormwater General Permit Page 22 numeric effluent limitations (see S8. Discharges to 303(d) or TMDL Waterbodies), the Permittee must, upon becoming aware of the circumstance: 1. Notify Ecology within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (refer to Special Condition S4.C.5.b.i. or www.ecy.wa.gov/programs/wq/stormwater/construction/turbidity.html for Regional ERTS phone numbers). 2. Immediately take action to prevent the discharge/pollution, or otherwise stop or correct the noncompliance, and, if applicable, repeat sampling and analysis of any noncompliance immediately and submit the results to Ecology within five (5) days of becoming aware of the violation. 3. Submit a detailed written report to Ecology within five (5) days, of the time the Permittee becomes aware of the circumstances, unless requested earlier by Ecology. The report must be submitted using Ecology’s Water Quality Permitting Portal (WQWebPortal) - Permit Submittals, unless a waiver from electronic reporting has been granted according to S5.B. The report must contain a description of the noncompliance, including exact dates and times, and if the noncompliance has not been corrected, the anticipated time it is expected to continue; and the steps taken or planned to reduce, eliminate, and prevent reoccurrence of the noncompliance. The Permittee must report any unanticipated bypass and/or upset that exceeds any effluent limit in the permit in accordance with the 24-hour reporting requirement contained in 40 C.F.R. 122.41(l)(6). Compliance with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply. Upon request of the Permittee, Ecology may waive the requirement for a written report on a case-by- case basis, if the immediate notification is received by Ecology within 24 hours. G. Access to Plans and Records 1. The Permittee must retain the following permit documentation (plans and records) on site, or within reasonable access to the site, for use by the operator or for on-site review by Ecology or the local jurisdiction: a. General Permit b. Permit Coverage Letter c. Stormwater Pollution Prevention Plan (SWPPP) d. Site Log Book 2. The Permittee must address written requests for plans and records listed above (Special Condition S5.G.1) as follows: Construction Stormwater General Permit Page 23 a. The Permittee must provide a copy of plans and records to Ecology within 14 days of receipt of a written request from Ecology. b. The Permittee must provide a copy of plans and records to the public when requested in writing. Upon receiving a written request from the public for the Permittee’s plans and records, the Permittee must either: i. Provide a copy of the plans and records to the requester within 14 days of a receipt of the written request; or ii. Notify the requester within 10 days of receipt of the written request of the location and times within normal business hours when the plans and records may be viewed; and provide access to the plans and records within 14 days of receipt of the written request; or iii. Within 14 days of receipt of the written request, the Permittee may submit a copy of the plans and records to Ecology for viewing and/or copying by the requester at an Ecology office, or a mutually agreed location. If plans and records are viewed and/or copied at a location other than at an Ecology office, the Permittee will provide reasonable access to copying services for which a reasonable fee may be charged. The Permittee must notify the requester within 10 days of receipt of the request where the plans and records may be viewed and/or copied. S6. PERMIT FEES The Permittee must pay permit fees assessed by Ecology. Fees for stormwater discharges covered under this permit are established by Chapter 173-224 WAC. Ecology continues to assess permit fees until the permit is terminated in accordance with Special Condition S10 or revoked in accordance with General Condition G5. S7. SOLID AND LIQUID WASTE DISPOSAL The Permittee must handle and dispose of solid and liquid wastes generated by construction activity, such as demolition debris, construction materials, contaminated materials, and waste materials from maintenance activities, including liquids and solids from cleaning catch basins and other stormwater facilities, in accordance with: A. Special Condition S3, Compliance with Standards B. WAC 173-216-110 C. Other applicable regulations S8. DISCHARGES TO 303(d) OR TMDL WATERBODIES A. Sampling and Numeric Effluent Limits For Certain Discharges to 303(d)-listed Waterbodies Construction Stormwater General Permit Page 24 1. Permittees who discharge to segments of waterbodies listed as impaired by the State of Washington under Section 303(d) of the Clean Water Act for turbidity, fine sediment, high pH, or phosphorus, must conduct water quality sampling according to the requirements of this section, and Special Conditions S4.C.2.b-f and S4.C.3.b-d, and must comply with the applicable numeric effluent limitations in S8.C and S8.D. 2. All references and requirements associated with Section 303(d) of the Clean Water Act mean the most current listing by Ecology of impaired waters (Category 5) that exists on January 1, 2016, or the date when the operator’s complete permit application is received by Ecology, whichever is later. B. Limits on Coverage for New Discharges to TMDL or 303(d)-listed Waters Operators of construction sites that discharge to a TMDL or 303(d)-listed waterbody are not eligible for coverage under this permit unless the operator: 1. Prevents exposing stormwater to pollutants for which the waterbody is impaired, and retains documentation in the SWPPP that details procedures taken to prevent exposure on site; or 2. Documents that the pollutants for which the waterbody is impaired are not present at the site, and retains documentation of this finding within the SWPPP; or 3. Provides Ecology with data indicating the discharge is not expected to cause or contribute to an exceedance of a water quality standard, and retains such data on site with the SWPPP. The operator must provide data and other technical information to Ecology that sufficiently demonstrate: a. For discharges to waters without an EPA-approved or -established TMDL, that the discharge of the pollutant for which the water is impaired will meet in- stream water quality criteria at the point of discharge to the waterbody; or b. For discharges to waters with an EPA-approved or -established TMDL, that there is sufficient remaining wasteload allocation in the TMDL to allow construction stormwater discharge and that existing dischargers to the waterbody are subject to compliance schedules designed to bring the waterbody into attainment with water quality standards. Operators of construction sites are eligible for coverage under this permit if Ecology issues permit coverage based upon an affirmative determination that the discharge will not cause or contribute to the existing impairment. C. Sampling and Numeric Effluent Limits for Discharges to Water Bodies on the 303(d) List for Turbidity, Fine Sediment, or Phosphorus 1. Permittees who discharge to segments of water bodies on the 303(d) list (Category 5) for turbidity, fine sediment, or phosphorus must conduct turbidity sampling in accordance with Special Condition S4.C.2 and comply with either of the numeric effluent limits noted in Table 5 below. Construction Stormwater General Permit Page 25 2. As an alternative to the 25 NTUs effluent limit noted in Table 5 below (applied at the point where stormwater [or authorized non-stormwater] is discharged off-site), Permittees may choose to comply with the surface water quality standard for turbidity. The standard is: no more than 5 NTUs over background turbidity when the background turbidity is 50 NTUs or less, or no more than a 10% increase in turbidity when the background turbidity is more than 50 NTUs. In order to use the water quality standard requirement, the sampling must take place at the following locations: a. Background turbidity in the 303(d)-listed receiving water immediately upstream (upgradient) or outside the area of influence of the discharge. b. Turbidity at the point of discharge into the 303(d)-listed receiving water, inside the area of influence of the discharge. 3. Discharges that exceed the numeric effluent limit for turbidity constitute a violation of this permit. 4. Permittees whose discharges exceed the numeric effluent limit shall sample discharges daily until the violation is corrected and comply with the non- compliance notification requirements in Special Condition S5.F. Table 5: Turbidity, Fine Sediment & Phosphorus Sampling and Limits for 303(d)-Listed Waters Parameter identified in 303(d) listing Parameter Sampled Unit Analytical Method Sampling Frequency Numeric Effluent Limit1  Turbidity  Fine Sediment  Phosphorus Turbidity NTU SM2130 Weekly, if discharging 25 NTUs, at the point where stormwater is discharged from the site; OR In compliance with the surface water quality standard for turbidity (S8.C.2.a) 1Permittees subject to a numeric effluent limit for turbidity may, at their discretion, choose either numeric effluent limitation based on site-specific considerations including, but not limited to, safety, access and convenience. D. Discharges to Water Bodies on the 303(d) List for High pH 1. Permittees who discharge to segments of water bodies on the 303(d) list (Category 5) for high pH must conduct pH sampling in accordance with the table below, and comply with the numeric effluent limit of pH 6.5 to 8.5 su (Table 6). Construction Stormwater General Permit Page 26 Table 6: pH Sampling and Limits for 303(d)-Listed Waters Parameter identified in 303(d) listing Parameter Sampled/Units Analytical Method Sampling Frequency Numeric Effluent Limit High pH pH /Standard Units pH meter Weekly, if discharging In the range of 6.5 – 8.5 2. At the Permittee’s discretion, compliance with the limit shall be assessed at one of the following locations: a. Directly in the 303(d)-listed waterbody segment, inside the immediate area of influence of the discharge; or b. Alternatively, the Permittee may measure pH at the point where the discharge leaves the construction site, rather than in the receiving water. 3. Discharges that exceed the numeric effluent limit for pH (outside the range of 6.5 – 8.5 su) constitute a violation of this permit. 4. Permittees whose discharges exceed the numeric effluent limit shall sample discharges daily until the violation is corrected and comply with the non- compliance notification requirements in Special Condition S5.F. E. Sampling and Limits for Sites Discharging to Waters Covered by a TMDL or Another Pollution Control Plan 1. Discharges to a waterbody that is subject to a Total Maximum Daily Load (TMDL) for turbidity, fine sediment, high pH, or phosphorus must be consistent with the TMDL. Refer to http://www.ecy.wa.gov/programs/wq/tmdl/ TMDLsbyWria/TMDLbyWria.html for more information on TMDLs. a. Where an applicable TMDL sets specific waste load allocations or requirements for discharges covered by this permit, discharges must be consistent with any specific waste load allocations or requirements established by the applicable TMDL. i. The Permittee must sample discharges weekly or as otherwise specified by the TMDL to evaluate compliance with the specific waste load allocations or requirements. ii. Analytical methods used to meet the monitoring requirements must conform to the latest revision of the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 CFR Part 136. Turbidity and pH methods need not be accredited or registered unless conducted at a laboratory which must otherwise be accredited or registered. b. Where an applicable TMDL has established a general waste load allocation for construction stormwater discharges, but has not identified specific requirements, Construction Stormwater General Permit Page 27 compliance with Special Conditions S4 (Monitoring) and S9 (SWPPPs) will constitute compliance with the approved TMDL. c. Where an applicable TMDL has not specified a waste load allocation for construction stormwater discharges, but has not excluded these discharges, compliance with Special Conditions S4 (Monitoring) and S9 (SWPPPs) will constitute compliance with the approved TMDL. d. Where an applicable TMDL specifically precludes or prohibits discharges from construction activity, the operator is not eligible for coverage under this permit. 2. Applicable TMDL means a TMDL for turbidity, fine sediment, high pH, or phosphorus that is completed and approved by EPA before January 1, 2016, or before the date the operator’s complete permit application is received by Ecology, whichever is later. TMDLs completed after the operator’s complete permit application is received by Ecology become applicable to the Permittee only if they are imposed through an administrative order by Ecology, or through a modification of permit coverage. S9. STORMWATER POLLUTION PREVENTION PLAN The Permittee must prepare and properly implement an adequate Stormwater Pollution Prevention Plan (SWPPP) for construction activity in accordance with the requirements of this permit beginning with initial soil disturbance and until final stabilization. A. The Permittee’s SWPPP must meet the following objectives: 1. To implement best management practices (BMPs) to prevent erosion and sedimentation, and to identify, reduce, eliminate or prevent stormwater contamination and water pollution from construction activity. 2. To prevent violations of surface water quality, ground water quality, or sediment management standards. 3. To control peak volumetric flow rates and velocities of stormwater discharges. B. General Requirements 1. The SWPPP must include a narrative and drawings. All BMPs must be clearly referenced in the narrative and marked on the drawings. The SWPPP narrative must include documentation to explain and justify the pollution prevention decisions made for the project. Documentation must include: a. Information about existing site conditions (topography, drainage, soils, vegetation, etc.). b. Potential erosion problem areas. c. The 13 elements of a SWPPP in Special Condition S9.D.1-13, including BMPs used to address each element. Construction Stormwater General Permit Page 28 d. Construction phasing/sequence and general BMP implementation schedule. e. The actions to be taken if BMP performance goals are not achieved—for example, a contingency plan for additional treatment and/or storage of stormwater that would violate the water quality standards if discharged. f. Engineering calculations for ponds, treatment systems, and any other designed structures. When a treatment system requires engineering calculations, these calculations must be included in the SWPPP. Engineering calculations do not need to be included in the SWPPP for treatment systems that do not require such calculations. 2. The Permittee must modify the SWPPP if, during inspections or investigations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the SWPPP is, or would be, ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The Permittee must then: a. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within 7 days of the inspection or investigation. b. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems no later than 10 days from the inspection or investigation. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when an extension is requested by a Permittee within the initial 10-day response period. c. Document BMP implementation and maintenance in the site log book. The Permittee must modify the SWPPP whenever there is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. C. Stormwater Best Management Practices (BMPs) BMPs must be consistent with: 1. Stormwater Management Manual for Western Washington (most current approved edition at the time this permit was issued), for sites west of the crest of the Cascade Mountains; or 2. Stormwater Management Manual for Eastern Washington (most current approved edition at the time this permit was issued), for sites east of the crest of the Cascade Mountains; or 3. Revisions to the manuals listed in Special Condition S9.C.1. & 2., or other stormwater management guidance documents or manuals which provide an equivalent level of pollution prevention, that are approved by Ecology and incorporated into this permit in accordance with the permit modification requirements of WAC 173-226-230; or Construction Stormwater General Permit Page 29 4. Documentation in the SWPPP that the BMPs selected provide an equivalent level of pollution prevention, compared to the applicable Stormwater Management Manuals, including: a. The technical basis for the selection of all stormwater BMPs (scientific, technical studies, and/or modeling) that support the performance claims for the BMPs being selected. b. An assessment of how the selected BMP will satisfy AKART requirements and the applicable federal technology-based treatment requirements under 40 CFR part 125.3. D. SWPPP – Narrative Contents and Requirements The Permittee must include each of the 13 elements below in Special Condition S9.D.1-13 in the narrative of the SWPPP and implement them unless site conditions render the element unnecessary and the exemption from that element is clearly justified in the SWPPP. 1. Preserve Vegetation/Mark Clearing Limits a. 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. b. Retain the duff layer, native topsoil, and natural vegetation in an undisturbed state to the maximum degree practicable. 2. Establish Construction Access a. Limit construction vehicle access and exit to one route, if possible. b. Stabilize access points with a pad of quarry spalls, crushed rock, or other equivalent BMPs, to minimize tracking sediment onto roads. c. Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in preventing tracking sediment onto roads. d. If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary (for example, during wet weather). Remove sediment from roads by shoveling, sweeping, or pickup and transport of the sediment to a controlled sediment disposal area. e. Conduct street washing only after sediment removal in accordance with Special Condition S9.D.2.d. Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. 3. Control Flow Rates a. Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the Construction Stormwater General Permit Page 30 velocity and peak volumetric flow rate of stormwater runoff from the project site, as required by local plan approval authority. b. Where necessary to comply with Special Condition S9.D.3.a, construct stormwater retention or detention facilities as one of the first steps in grading. Assure that detention facilities function properly before constructing site improvements (for example, impervious surfaces). c. If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. 4. Install Sediment Controls The Permittee must design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, the Permittee must design, install and maintain such controls to: a. Construct sediment control BMPs (sediment ponds, traps, filters, infiltration facilities, etc.) as one of the first steps in grading. These BMPs must be functional before other land disturbing activities take place. b. 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. c. 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 of Special Condition S9.D.3.a. d. 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. e. Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal and maximize stormwater infiltration, unless infeasible. f. 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. 5. Stabilize Soils a. The Permittee must 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 Construction Stormwater General Permit Page 31 (PAM), the early application of gravel base on areas to be paved, and dust control. b. The Permittee must control stormwater volume and velocity within the site to minimize soil erosion. c. The Permittee must 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. d. Depending on the geographic location of the project, the Permittee must not allow soils to remain exposed and unworked for more than the time periods set forth below to prevent erosion: West of the Cascade Mountains Crest During the dry season (May 1 - September 30): 7 days During the wet season (October 1 - April 30): 2 days East of the Cascade Mountains Crest, except for Central Basin* During the dry season (July 1 - September 30): 10 days During the wet season (October 1 - June 30): 5 days The Central Basin*, East of the Cascade Mountains Crest During the dry season (July 1 - September 30): 30 days During the wet season (October 1 - June 30): 15 days *Note: The Central Basin is defined as the portions of Eastern Washington with mean annual precipitation of less than 12 inches. e. The Permittee must stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. f. The Permittee must stabilize soil stockpiles from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. g. The Permittee must minimize the amount of soil exposed during construction activity. h. The Permittee must minimize the disturbance of steep slopes. i. The Permittee must minimize soil compaction and, unless infeasible, preserve topsoil. 6. Protect Slopes a. The Permittee must 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 (for example, track walking). Construction Stormwater General Permit Page 32 b. The Permittee must 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. c. At the top of slopes, collect drainage in pipe slope drains or protected channels to prevent erosion. i. West of the Cascade Mountains Crest: Temporary pipe slope drains must handle the peak 10-minute flow rate from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate predicted 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.” ii. East of the Cascade Mountains Crest: Temporary pipe slope drains must handle the expected peak flow rate from a 6-month, 3-hour storm for the developed condition, referred to as the short duration storm. d. Place excavated material on the uphill side of trenches, consistent with safety and space considerations. e. Place check dams at regular intervals within constructed channels that are cut down a slope. 7. Protect Drain Inlets a. 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. b. 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). 8. Stabilize Channels and Outlets a. Design, construct and stabilize all on-site conveyance channels to prevent erosion from the following expected peak flows: i. West of the Cascade Mountains Crest: Channels must handle the peak 10-minute flow rate from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate 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 Construction Stormwater General Permit Page 33 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 WWHM to predict flows, bare soil areas should be modeled as "landscaped area.” ii. East of the Cascade Mountains Crest: Channels must handle the expected peak flow rate from a 6-month, 3-hour storm for the developed condition, referred to as the short duration storm. b. Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes, and downstream reaches at the outlets of all conveyance systems. 9. Control Pollutants Design, install, implement and maintain effective pollution prevention measures to minimize the discharge of pollutants. The Permittee must: a. 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. b. 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. c. Conduct maintenance, fueling, and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. d. 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. e. 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. f. 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, recycled concrete stockpiles, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete Construction Stormwater General Permit Page 34 pumping and mixer washout waters. (Also refer to the definition for "concrete wastewater" in Appendix A--Definitions.) g. Adjust the pH of stormwater or authorized non-stormwater if necessary to prevent an exceedance of groundwater and/or surface water quality standards. h. Assure that washout of concrete trucks is performed off-site or in designated concrete washout areas only. Do not wash out concrete truck drums or concrete handling equipment onto the ground, or into storm drains, open ditches, streets, or streams. Washout of concrete handling equipment may be disposed of in a designated concrete washout area or in a formed area awating concrete where it will not contaminate surface or ground water. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge directly to groundwater or surface waters of the State is prohibited. Do not wash out to formed areas awaiting LID facilities. i. Obtain written approval from Ecology before using any chemical treatment, with the exception of CO2 or dry ice used to adjust pH. j. Uncontaminated water from water-only based shaft drilling for construction of building, road, and bridge foundations may be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters. Prior to infiltration, water from water-only based shaft drilling that comes into contact with curing concrete must be neutralized until pH is in the range of 6.5 to 8.5 (su). 10. Control Dewatering a. Permittees must 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. b. Permittees may discharge clean, non-turbid dewatering water, such as well- point ground water, to systems tributary to, or directly into surface waters of the State, as specified in Special Condition S9.D.8, provided the dewatering flow does not cause erosion or flooding of receiving waters. 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. c. Other dewatering treatment or disposal options may include: i. Infiltration. ii. Transport off site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute state waters. Construction Stormwater General Permit Page 35 iii. Ecology-approved on-site chemical treatment or other suitable treatment technologies (see S9.D.9.i. regarding chemical treatment written approval). iv. Sanitary or combined sewer discharge with local sewer district approval, if there is no other option. v. Use of a sedimentation bag with discharge to a ditch or swale for small volumes of localized dewatering. d. Permittees must handle highly turbid or contaminated dewatering water separately from stormwater. 11. Maintain BMPs a. Permittees must 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. b. Permittees must 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. 12. Manage the Project a. Phase development projects to the maximum degree practicable and take into account seasonal work limitations. b. Inspection and monitoring – Inspect, maintain and repair all BMPs as needed to assure continued performance of their intended function. Conduct site inspections and monitoring in accordance with Special Condition S4. c. Maintaining an updated construction SWPPP – Maintain, update, and implement the SWPPP in accordance with Special Conditions S3, S4 and S9. 13. Protect Low Impact Development (LID) BMPs The primary purpose of LID BMPs/On-site LID Stormwater Management BMPs is to reduce the disruption of the natural site hydrology. LID BMPs are permanent facilities. a. Permittees must protect all Bioretention and Rain Garden facilities from sedimentation through installation and maintenance of erosion and sediment control BMPs on portions of the site that drain into the Bioretention and/or Rain Garden facilities. Restore the facilities to their fully functioning condition if they accumulate sediment during construction. Restoring the facility must include removal of sediment and any sediment-laden Bioretention/Rain Garden soils, and replacing the removed soils with soils meeting the design specification. Construction Stormwater General Permit Page 36 b. Permittees must maintain the infiltration capabilities of Bioretention and Rain Garden facilities by protecting against compaction by construction equipment and foot traffic. Protect completed lawn and landscaped areas from compaction due to construction equipment. c. Permittees must control erosion and avoid introducing sediment from surrounding land uses onto permeable pavements. Do not allow muddy construction equipment on the base material or pavement. Do not allow sediment-laden runoff onto permeable pavements. d. Permittees must clean permeable pavements fouled with sediments or no longer passing an initial infiltration test using local stormwater manual methodology or the manufacturer’s procedures. e. Permittees must keep all heavy equipment off existing soils under LID facilities that have been excavated to final grade to retain the infiltration rate of the soils. E. SWPPP – Map Contents and Requirements The Permittee’s SWPPP must also include a vicinity map or general location map (for example, a USGS quadrangle map, a portion of a county or city map, or other appropriate map) with enough detail to identify the location of the construction site and receiving waters within one mile of the site. The SWPPP must also include a legible site map (or maps) showing the entire construction site. The following features must be identified, unless not applicable due to site conditions: 1. The direction of north, property lines, and existing structures and roads. 2. Cut and fill slopes indicating the top and bottom of slope catch lines. 3. Approximate slopes, contours, and direction of stormwater flow before and after major grading activities. 4. Areas of soil disturbance and areas that will not be disturbed. 5. Locations of structural and nonstructural controls (BMPs) identified in the SWPPP. 6. Locations of off-site material, stockpiles, waste storage, borrow areas, and vehicle/equipment storage areas. 7. Locations of all surface water bodies, including wetlands. 8. Locations where stormwater or non-stormwater discharges off-site and/or to a surface waterbody, including wetlands. 9. Location of water quality sampling station(s), if sampling is required by state or local permitting authority. Construction Stormwater General Permit Page 37 10. Areas where final stabilization has been accomplished and no further construction- phase permit requirements apply. 11. Location or proposed location of LID facilities. S10. NOTICE OF TERMINATION A. The site is eligible for termination of coverage when it has met any of the following conditions: 1. The site has undergone final stabilization, the Permittee has removed all temporary BMPs (except biodegradable BMPs clearly manufactured with the intention for the material to be left in place and not interfere with maintenance or land use), and all stormwater discharges associated with construction activity have been eliminated; or 2. All portions of the site that have not undergone final stabilization per Special Condition S10.A.1 have been sold and/or transferred (per General Condition G9), and the Permittee no longer has operational control of the construction activity; or 3. For residential construction only, the Permittee has completed temporary stabilization and the homeowners have taken possession of the residences. B. When the site is eligible for termination, the Permittee must submit a complete and accurate Notice of Termination (NOT) form, signed in accordance with General Condition G2, to: Department of Ecology Water Quality Program – Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 When an electronic termination form is available, the Permittee may choose to submit a complete and accurate Notice of Termination (NOT) form through the Water Quality Permitting Portal rather than mailing a hardcopy as noted above. The termination is effective on the thirty-first calendar day following the date Ecology receives a complete NOT form, unless Ecology notifies the Permittee that the termination request is denied because the Permittee has not met the eligibility requirements in Special Condition S10.A. Permittees are required to comply with all conditions and effluent limitations in the permit until the permit has been terminated. Permittees transferring the property to a new property owner or operator/Permittee are required to complete and submit the Notice of Transfer form to Ecology, but are not required to submit a Notice of Termination form for this type of transaction. Construction Stormwater General Permit Page 38 GENERAL CONDITIONS G1. DISCHARGE VIOLATIONS All discharges and activities authorized by this general permit must be consistent with the terms and conditions of this general permit. Any discharge of any pollutant more frequent than or at a level in excess of that identified and authorized by the general permit must constitute a violation of the terms and conditions of this permit. G2. SIGNATORY REQUIREMENTS A. All permit applications must bear a certification of correctness to be signed: 1. In the case of corporations, by a responsible corporate officer; 2. In the case of a partnership, by a general partner of a partnership; 3. In the case of sole proprietorship, by the proprietor; or 4. In the case of a municipal, state, or other public facility, by either a principal executive officer or ranking elected official. B. All reports required by this permit and other information requested by Ecology (including NOIs, NOTs, and Transfer of Coverage forms) must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by a person described above and submitted to Ecology. 2. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility, such as the position of plant manager, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters. C. Changes to authorization. If an authorization under paragraph G2.B.2 above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of paragraph G2.B.2 above must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Certification. Any person signing a document under this section must make the following certification: “I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering information, the information submitted is, to the best of my Construction Stormwater General Permit Page 39 knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.” G3. RIGHT OF INSPECTION AND ENTRY The Permittee must allow an authorized representative of Ecology, upon the presentation of credentials and such other documents as may be required by law: A. To enter upon the premises where a discharge is located or where any records are kept under the terms and conditions of this permit. B. To have access to and copy – at reasonable times and at reasonable cost – any records required to be kept under the terms and conditions of this permit. C. To inspect – at reasonable times – any facilities, equipment (including monitoring and control equipment), practices, methods, or operations regulated or required under this permit. D. To sample or monitor – at reasonable times – any substances or parameters at any location for purposes of assuring permit compliance or as otherwise authorized by the Clean Water Act. G4. GENERAL PERMIT MODIFICATION AND REVOCATION This permit may be modified, revoked and reissued, or terminated in accordance with the provisions of Chapter 173-226 WAC. Grounds for modification, revocation and reissuance, or termination include, but are not limited to, the following: A. When a change occurs in the technology or practices for control or abatement of pollutants applicable to the category of dischargers covered under this permit. B. When effluent limitation guidelines or standards are promulgated pursuant to the CWA or Chapter 90.48 RCW, for the category of dischargers covered under this permit. C. When a water quality management plan containing requirements applicable to the category of dischargers covered under this permit is approved, or D. When information is obtained that indicates cumulative effects on the environment from dischargers covered under this permit are unacceptable. G5. REVOCATION OF COVERAGE UNDER THE PERMIT Pursuant to Chapter 43.21B RCW and Chapter 173-226 WAC, the Director may terminate coverage for any discharger under this permit for cause. Cases where coverage may be terminated include, but are not limited to, the following: A. Violation of any term or condition of this permit. B. Obtaining coverage under this permit by misrepresentation or failure to disclose fully all relevant facts. Construction Stormwater General Permit Page 40 C. A change in any condition that requires either a temporary or permanent reduction or elimination of the permitted discharge. D. Failure or refusal of the Permittee to allow entry as required in RCW 90.48.090. E. A determination that the permitted activity endangers human health or the environment, or contributes to water quality standards violations. F. Nonpayment of permit fees or penalties assessed pursuant to RCW 90.48.465 and Chapter 173-224 WAC. G. Failure of the Permittee to satisfy the public notice requirements of WAC 173-226- 130(5), when applicable. The Director may require any discharger under this permit to apply for and obtain coverage under an individual permit or another more specific general permit. Permittees who have their coverage revoked for cause according to WAC 173-226-240 may request temporary coverage under this permit during the time an individual permit is being developed, provided the request is made within ninety (90) days from the time of revocation and is submitted along with a complete individual permit application form. G6. REPORTING A CAUSE FOR MODIFICATION The Permittee must submit a new application, or a supplement to the previous application, whenever a material change to the construction activity or in the quantity or type of discharge is anticipated which is not specifically authorized by this permit. This application must be submitted at least sixty (60) days prior to any proposed changes. Filing a request for a permit modification, revocation and reissuance, or termination, or a notification of planned changes or anticipated noncompliance does not relieve the Permittee of the duty to comply with the existing permit until it is modified or reissued. G7. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in this permit will be construed as excusing the Permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations. G8. DUTY TO REAPPLY The Permittee must apply for permit renewal at least 180 days prior to the specified expiration date of this permit. The Permittee must reapply using the electronic application form (NOI) available on Ecology’s website. Permittees unable to submit electronically (for example, those who do not have an internet connection) must contact Ecology to request a waiver and obtain instructions on how to obtain a paper NOI. Department of Ecology Water Quality Program - Construction Stormwater PO Box 47696 Olympia, Washington 98504-7696 Construction Stormwater General Permit Page 41 G9. TRANSFER OF GENERAL PERMIT COVERAGE Coverage under this general permit is automatically transferred to a new discharger, including operators of lots/parcels within a common plan of development or sale, if: A. A written agreement (Transfer of Coverage Form) between the current discharger (Permittee) and new discharger, signed by both parties and containing a specific date for transfer of permit responsibility, coverage, and liability (including any Administrative Orders associated with the Permit) is submitted to the Director; and B. The Director does not notify the current discharger and new discharger of the Director’s intent to revoke coverage under the general permit. If this notice is not given, the transfer is effective on the date specified in the written agreement. When a current discharger (Permittee) transfers a portion of a permitted site, the current discharger must also submit an updated application form (NOI) to the Director indicating the remaining permitted acreage after the transfer. G10. REMOVED SUBSTANCES The Permittee must not re-suspend or reintroduce collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of stormwater to the final effluent stream for discharge to state waters. G11. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all information that Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology, upon request, copies of records required to be kept by this permit [40 CFR 122.41(h)]. G12. OTHER REQUIREMENTS OF 40 CFR All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference. G13. ADDITIONAL MONITORING Ecology may establish specific monitoring requirements in addition to those contained in this permit by administrative order or permit modification. G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit shall be deemed guilty of a crime, and upon conviction thereof shall be punished by a fine of up to ten thousand dollars ($10,000) and costs of prosecution, or by imprisonment at the discretion of the court. Each day upon which a willful violation occurs may be deemed a separate and additional violation. Construction Stormwater General Permit Page 42 Any person who violates the terms and conditions of a waste discharge permit shall incur, in addition to any other penalty as provided by law, a civil penalty in the amount of up to ten thousand dollars ($10,000) for every such violation. Each and every such violation shall be a separate and distinct offense, and in case of a continuing violation, every day’s continuance shall be deemed to be a separate and distinct violation. G15. UPSET Definition – “Upset” means an exceptional incident in which there is unintentional and temporary noncompliance with technology-based permit effluent limitations because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. An upset constitutes an affirmative defense to an action brought for noncompliance with such technology-based permit effluent limitations if the requirements of the following paragraph are met. A Permittee who wishes to establish the affirmative defense of upset must demonstrate, through properly signed, contemporaneous operating logs or other relevant evidence that: 1) an upset occurred and that the Permittee can identify the cause(s) of the upset; 2) the permitted facility was being properly operated at the time of the upset; 3) the Permittee submitted notice of the upset as required in Special Condition S5.F, and; 4) the Permittee complied with any remedial measures required under this permit. In any enforcement proceeding, the Permittee seeking to establish the occurrence of an upset has the burden of proof. G16. PROPERTY RIGHTS This permit does not convey any property rights of any sort, or any exclusive privilege. G17. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. G18. TOXIC POLLUTANTS The Permittee must comply with effluent standards or prohibitions established under Section 307(a) of the Clean Water Act for toxic pollutants within the time provided in the regulations that establish those standards or prohibitions, even if this permit has not yet been modified to incorporate the requirement. Construction Stormwater General Permit Page 43 G19. PENALTIES FOR TAMPERING The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required to be maintained under this permit shall, upon conviction, be punished by a fine of not more than $10,000 per violation, or by imprisonment for not more than two years per violation, or by both. If a conviction of a person is for a violation committed after a first conviction of such person under this condition, punishment shall be a fine of not more than $20,000 per day of violation, or imprisonment of not more than four (4) years, or both. G20. REPORTING PLANNED CHANGES The Permittee must, as soon as possible, give notice to Ecology of planned physical alterations, modifications or additions to the permitted construction activity. The Permittee should be aware that, depending on the nature and size of the changes to the original permit, a new public notice and other permit process requirements may be required. Changes in activities that require reporting to Ecology include those that will result in: A. The permitted facility being determined to be a new source pursuant to 40 CFR 122.29(b). B. A significant change in the nature or an increase in quantity of pollutants discharged, including but not limited to: for sites 5 acres or larger, a 20% or greater increase in acreage disturbed by construction activity. C. A change in or addition of surface water(s) receiving stormwater or non-stormwater from the construction activity. D. A change in the construction plans and/or activity that affects the Permittee’s monitoring requirements in Special Condition S4. Following such notice, permit coverage may be modified, or revoked and reissued pursuant to 40 CFR 122.62(a) to specify and limit any pollutants not previously limited. Until such modification is effective, any new or increased discharge in excess of permit limits or not specifically authorized by this permit constitutes a violation. G21. REPORTING OTHER INFORMATION Where the Permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or in any report to Ecology, it must promptly submit such facts or information. G22. REPORTING ANTICIPATED NON-COMPLIANCE The Permittee must give advance notice to Ecology by submission of a new application or supplement thereto at least forty-five (45) days prior to commencement of such discharges, of any facility expansions, production increases, or other planned changes, such as process modifications, in the permitted facility or activity which may result in noncompliance with permit limits or conditions. Any maintenance of facilities, which might necessitate Construction Stormwater General Permit Page 44 unavoidable interruption of operation and degradation of effluent quality, must be scheduled during non-critical water quality periods and carried out in a manner approved by Ecology. G23. REQUESTS TO BE EXCLUDED FROM COVERAGE UNDER THE PERMIT Any discharger authorized by this permit may request to be excluded from coverage under the general permit by applying for an individual permit. The discharger must submit to the Director an application as described in WAC 173-220-040 or WAC 173-216-070, whichever is applicable, with reasons supporting the request. These reasons will fully document how an individual permit will apply to the applicant in a way that the general permit cannot. Ecology may make specific requests for information to support the request. The Director will either issue an individual permit or deny the request with a statement explaining the reason for the denial. When an individual permit is issued to a discharger otherwise subject to the construction stormwater general permit, the applicability of the construction stormwater general permit to that Permittee is automatically terminated on the effective date of the individual permit. G24. APPEALS A. The terms and conditions of this general permit, as they apply to the appropriate class of dischargers, are subject to appeal by any person within 30 days of issuance of this general permit, in accordance with Chapter 43.21B RCW, and Chapter 173-226 WAC. B. The terms and conditions of this general permit, as they apply to an individual discharger, are appealable in accordance with Chapter 43.21B RCW within 30 days of the effective date of coverage of that discharger. Consideration of an appeal of general permit coverage of an individual discharger is limited to the general permit’s applicability or nonapplicability to that individual discharger. C. The appeal of general permit coverage of an individual discharger does not affect any other dischargers covered under this general permit. If the terms and conditions of this general permit are found to be inapplicable to any individual discharger(s), the matter shall be remanded to Ecology for consideration of issuance of an individual permit or permits. G25. SEVERABILITY The provisions of this permit are severable, and if any provision of this permit, or application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of this permit shall not be affected thereby. G26. BYPASS PROHIBITED A. Bypass Procedures Bypass, which is the intentional diversion of waste streams from any portion of a treatment facility, is prohibited for stormwater events below the design criteria for Construction Stormwater General Permit Page 45 stormwater management. Ecology may take enforcement action against a Permittee for bypass unless one of the following circumstances (1, 2, 3 or 4) is applicable. 1. Bypass of stormwater is consistent with the design criteria and part of an approved management practice in the applicable stormwater management manual. 2. Bypass for essential maintenance without the potential to cause violation of permit limits or conditions. Bypass is authorized if it is for essential maintenance and does not have the potential to cause violations of limitations or other conditions of this permit, or adversely impact public health. 3. Bypass of stormwater is unavoidable, unanticipated, and results in noncompliance of this permit. This bypass is permitted only if: a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage. “Severe property damage” means substantial physical damage to property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. b. There are no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, maintenance during normal periods of equipment downtime (but not if adequate backup equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occurred during normal periods of equipment downtime or preventative maintenance), or transport of untreated wastes to another treatment facility. c. Ecology is properly notified of the bypass as required in Special Condition S5.F of this permit. 4. A planned action that would cause bypass of stormwater and has the potential to result in noncompliance of this permit during a storm event. The Permittee must notify Ecology at least thirty (30) days before the planned date of bypass. The notice must contain: a. A description of the bypass and its cause. b. An analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing. c. A cost-effectiveness analysis of alternatives including comparative resource damage assessment. d. The minimum and maximum duration of bypass under each alternative. e. A recommendation as to the preferred alternative for conducting the bypass. Construction Stormwater General Permit Page 46 f. The projected date of bypass initiation. g. A statement of compliance with SEPA. h. A request for modification of water quality standards as provided for in WAC 173-201A-110, if an exceedance of any water quality standard is anticipated. i. Steps taken or planned to reduce, eliminate, and prevent reoccurrence of the bypass. 5. For probable construction bypasses, the need to bypass is to be identified as early in the planning process as possible. The analysis required above must be considered during preparation of the Stormwater Pollution Prevention Plan (SWPPP) and must be included to the extent practical. In cases where the probable need to bypass is determined early, continued analysis is necessary up to and including the construction period in an effort to minimize or eliminate the bypass. Ecology will consider the following before issuing an administrative order for this type bypass: a. If the bypass is necessary to perform construction or maintenance-related activities essential to meet the requirements of this permit. b. If there are feasible alternatives to bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production, maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility. c. If the bypass is planned and scheduled to minimize adverse effects on the public and the environment. After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve, conditionally approve, or deny the request. The public must be notified and given an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Approval of a request to bypass will be by administrative order issued by Ecology under RCW 90.48.120. B. Duty to Mitigate The Permittee is required to take all reasonable steps to minimize or prevent any discharge or sludge use or disposal in violation of this permit that has a reasonable likelihood of adversely affecting human health or the environment. Construction Stormwater General Permit Page 47 APPENDIX A – DEFINITIONS AKART is an acronym for “all known, available, and reasonable methods of prevention, control, and treatment.” AKART represents the most current methodology that can be reasonably required for preventing, controlling, or abating the pollutants and controlling pollution associated with a discharge. Applicable TMDL means a TMDL for turbidity, fine sediment, high pH, or phosphorus, which was completed and approved by EPA before January 1, 2016, or before the date the operator’s complete permit application is received by Ecology, whichever is later. Applicant means an operator seeking coverage under this permit. Benchmark means a pollutant concentration used as a permit threshold, below which a pollutant is considered unlikely to cause a water quality violation, and above which it may. When pollutant concentrations exceed benchmarks, corrective action requirements take effect. Benchmark values are not water quality standards and are not numeric effluent limitations; they are indicator values. Best Management Practices (BMPs) means schedules of activities, prohibitions of practices, maintenance procedures, and other physical, structural and/or managerial practices to prevent or reduce the pollution of waters of the State. BMPs include treatment systems, operating procedures, and practices to control: stormwater associated with construction activity, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. Buffer means an area designated by a local jurisdiction that is contiguous to and intended to protect a sensitive area. Bypass means the intentional diversion of waste streams from any portion of a treatment facility. Calendar Day A period of 24 consecutive hours starting at 12:00 midnight and ending the following 12:00 midnight. Calendar Week (same as Week) means a period of seven consecutive days starting at 12:01 a.m. (0:01 hours) on Sunday. Certified Erosion and Sediment Control Lead (CESCL) means a person who has current certification through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (see BMP C160 in the SWMM). Chemical Treatment means the addition of chemicals to stormwater and/or authorized non- stormwater prior to filtration and discharge to surface waters. Clean Water Act (CWA) means the Federal Water Pollution Control Act enacted by Public Law 92-500, as amended by Public Laws 95-217, 95-576, 96-483, and 97-117; USC 1251 et seq. Combined Sewer means a sewer which has been designed to serve as a sanitary sewer and a storm sewer, and into which inflow is allowed by local ordinance. Construction Stormwater General Permit Page 48 Common Plan of Development or Sale means a site where multiple separate and distinct construction activities may be taking place at different times on different schedules and/or by different contractors, but still under a single plan. Examples include: 1) phased projects and projects with multiple filings or lots, even if the separate phases or filings/lots will be constructed under separate contract or by separate owners (e.g., a development where lots are sold to separate builders); 2) a development plan that may be phased over multiple years, but is still under a consistent plan for long-term development; 3) projects in a contiguous area that may be unrelated but still under the same contract, such as construction of a building extension and a new parking lot at the same facility; and 4) linear projects such as roads, pipelines, or utilities. If the project is part of a common plan of development or sale, the disturbed area of the entire plan must be used in determining permit requirements. Composite Sample means a mixture of grab samples collected at the same sampling point at different times, formed either by continuous sampling or by mixing discrete samples. May be "time-composite" (collected at constant time intervals) or "flow-proportional" (collected either as a constant sample volume at time intervals proportional to stream flow, or collected by increasing the volume of each aliquot as the flow increases while maintaining a constant time interval between the aliquots. Concrete Wastewater means any water used in the production, pouring and/or clean-up of concrete or concrete products, and any water used to cut, grind, wash, or otherwise modify concrete or concrete products. Examples include water used for or resulting from concrete truck/mixer/pumper/tool/chute rinsing or washing, concrete saw cutting and surfacing (sawing, coring, grinding, roughening, hydro-demolition, bridge and road surfacing). When stormwater comingles with concrete wastewater, the resulting water is considered concrete wastewater and must be managed to prevent discharge to waters of the State, including ground water. Construction Activity means land disturbing operations including clearing, grading or excavation which disturbs the surface of the land. Such activities may include road construction, construction of residential houses, office buildings, or industrial buildings, site preparation, soil compaction, movement and stockpiling of topsoils, and demolition activity. Contaminant means any hazardous substance that does not occur naturally or occurs at greater than natural background levels. See definition of “hazardous substance” and WAC 173-340-200. Contaminated Groundwater means groundwater which contains contaminants, pollutants, or hazardous substances that do not occur naturally or occur at levels greater than natural background. Contaminated Soil means soil which contains contaminants, pollutants, or hazardous substances that do not occur naturally or occur at levels greater than natural background. Demonstrably Equivalent means that the technical basis for the selection of all stormwater BMPs is documented within a SWPPP, including: 1. The method and reasons for choosing the stormwater BMPs selected. Construction Stormwater General Permit Page 49 2. The pollutant removal performance expected from the BMPs selected. 3. The technical basis supporting the performance claims for the BMPs selected, including any available data concerning field performance of the BMPs selected. 4. An assessment of how the selected BMPs will comply with state water quality standards. 5. An assessment of how the selected BMPs will satisfy both applicable federal technology- based treatment requirements and state requirements to use all known, available, and reasonable methods of prevention, control, and treatment (AKART). Department means the Washington State Department of Ecology. Detention means the temporary storage of stormwater to improve quality and/or to reduce the mass flow rate of discharge. Dewatering means the act of pumping ground water or stormwater away from an active construction site. Director means the Director of the Washington State Department of Ecology or his/her authorized representative. Discharger means an owner or operator of any facility or activity subject to regulation under Chapter 90.48 RCW or the Federal Clean Water Act. Domestic Wastewater means water carrying human wastes, including kitchen, bath, and laundry wastes from residences, buildings, industrial establishments, or other places, together with such ground water infiltration or surface waters as may be present. Ecology means the Washington State Department of Ecology. Engineered Soils means the use of soil amendments including, but not limited, to Portland cement treated base (CTB), cement kiln dust (CKD), or fly ash to achieve certain desirable soil characteristics. Equivalent BMPs means operational, source control, treatment, or innovative BMPs which result in equal or better quality of stormwater discharge to surface water or to ground water than BMPs selected from the SWMM. Erosion means the wearing away of the land surface by running water, wind, ice, or other geological agents, including such processes as gravitational creep. Erosion and Sediment Control BMPs means BMPs intended to prevent erosion and sedimentation, such as preserving natural vegetation, seeding, mulching and matting, plastic covering, filter fences, sediment traps, and ponds. Erosion and sediment control BMPs are synonymous with stabilization and structural BMPs. Federal Operator is an entity that meets the definition of “Operator” in this permit and is either any department, agency or instrumentality of the executive, legislative, and judicial branches of Construction Stormwater General Permit Page 50 the Federal government of the United States, or another entity, such as a private contractor, performing construction activity for any such department, agency, or instrumentality. Final Stabilization (same as fully stabilized or full stabilization) means the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (examples of permanent non-vegetative stabilization methods include, but are not limited to riprap, gabions or geotextiles) which prevents erosion. Ground Water means water in a saturated zone or stratum beneath the land surface or a surface waterbody. Hazardous Substance means any dangerous or extremely hazardous waste as defined in RCW 70.105.010 (5) and (6), or any dangerous or extremely dangerous waste as designated by rule under chapter 70.105 RCW; any hazardous substance as defined in RCW 70.105.010(10) or any hazardous substance as defined by rule under chapter 70.105 RCW; any substance that, on the effective date of this section, is a hazardous substance under section 101(14) of the federal cleanup law, 42 U.S.C., Sec. 9601(14); petroleum or petroleum products; and any substance or category of substances, including solid waste decomposition products, determined by the director by rule to present a threat to human health or the environment if released into the environment. The term hazardous substance does not include any of the following when contained in an underground storage tank from which there is not a release: crude oil or any fraction thereof or petroleum, if the tank is in compliance with all applicable federal, state, and local law. Injection Well means a well that is used for the subsurface emplacement of fluids. (See Well.) Jurisdiction means a political unit such as a city, town or county; incorporated for local self- government. National Pollutant Discharge Elimination System (NPDES) means the national program for issuing, modifying, revoking and reissuing, terminating, monitoring, and enforcing permits, and imposing and enforcing pretreatment requirements, under sections 307, 402, 318, and 405 of the Federal Clean Water Act, for the discharge of pollutants to surface waters of the State from point sources. These permits are referred to as NPDES permits and, in Washington State, are administered by the Washington State Department of Ecology. Notice of Intent (NOI) means the application for, or a request for coverage under this general permit pursuant to WAC 173-226-200. Notice of Termination (NOT) means a request for termination of coverage under this general permit as specified by Special Condition S10 of this permit. Operator means any party associated with a construction project that meets either of the following two criteria:  The party has operational control over construction plans and specifications, including the ability to make modifications to those plans and specifications; or Construction Stormwater General Permit Page 51  The party has day-to-day operational control of those activities at a project that are necessary to ensure compliance with a SWPPP for the site or other permit conditions (e.g., they are authorized to direct workers at a site to carry out activities required by the SWPPP or comply with other permit conditions). Permittee means individual or entity that receives notice of coverage under this general permit. pH means a liquid’s measure of acidity or alkalinity. A pH of 7 is defined as neutral. Large variations above or below this value are considered harmful to most aquatic life. pH Monitoring Period means the time period in which the pH of stormwater runoff from a site must be tested a minimum of once every seven days to determine if stormwater pH is between 6.5 and 8.5. Point Source means any discernible, confined, and discrete conveyance, including but not limited to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, and container from which pollutants are or may be discharged to surface waters of the State. This term does not include return flows from irrigated agriculture. (See Fact Sheet for further explanation.) Pollutant means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, domestic sewage sludge (biosolids), munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste. This term does not include sewage from vessels within the meaning of section 312 of the CWA, nor does it include dredged or fill material discharged in accordance with a permit issued under section 404 of the CWA. Pollution means contamination or other alteration of the physical, chemical, or biological properties of waters of the State; including change in temperature, taste, color, turbidity, or odor of the waters; or such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the State as will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the public health, safety or welfare; or to domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses; or to livestock, wild animals, birds, fish or other aquatic life. Process Wastewater means any water which, during manufacturing or processing, comes into direct contact with or results from the production or use of any raw material, intermediate product, finished product, byproduct, or waste product. If stormwater commingles with process wastewater, the commingled water is considered process wastewater. Receiving Water means the waterbody at the point of discharge. If the discharge is to a storm sewer system, either surface or subsurface, the receiving water is the waterbody to which the storm system discharges. Systems designed primarily for other purposes such as for ground water drainage, redirecting stream natural flows, or for conveyance of irrigation water/return flows that coincidentally convey stormwater are considered the receiving water. Construction Stormwater General Permit Page 52 Representative means a stormwater or wastewater sample which represents the flow and characteristics of the discharge. Representative samples may be a grab sample, a time- proportionate composite sample, or a flow proportionate sample. Ecology’s Construction Stormwater Monitoring Manual provides guidance on representative sampling. Responsible Corporate Officer for the purpose of signatory authority means: (i) a president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision-making functions for the corporation, or (ii) the manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures (40 CFR 122.22). Sanitary Sewer means a sewer which is designed to convey domestic wastewater. Sediment means the fragmented material that originates from the weathering and erosion of rocks or unconsolidated deposits, and is transported by, suspended in, or deposited by water. Sedimentation means the depositing or formation of sediment. Sensitive Area means a waterbody, wetland, stream, aquifer recharge area, or channel migration zone. SEPA (State Environmental Policy Act) means the Washington State Law, RCW 43.21C.020, intended to prevent or eliminate damage to the environment. Significant Amount means an amount of a pollutant in a discharge that is amenable to available and reasonable methods of prevention or treatment; or an amount of a pollutant that has a reasonable potential to cause a violation of surface or ground water quality or sediment management standards. Significant Concrete Work means greater than 1000 cubic yards poured concrete or recycled concrete used over the life of a project. Significant Contributor of Pollutants means a facility determined by Ecology to be a contributor of a significant amount(s) of a pollutant(s) to waters of the State of Washington. Site means the land or water area where any "facility or activity" is physically located or conducted. Source Control BMPs means physical, structural or mechanical devices or facilities that are intended to prevent pollutants from entering stormwater. A few examples of source control Construction Stormwater General Permit Page 53 BMPs are erosion control practices, maintenance of stormwater facilities, constructing roofs over storage and working areas, and directing wash water and similar discharges to the sanitary sewer or a dead end sump. Stabilization means the application of appropriate BMPs to prevent the erosion of soils, such as, temporary and permanent seeding, vegetative covers, mulching and matting, plastic covering and sodding. See also the definition of Erosion and Sediment Control BMPs. Storm Drain means any drain which drains directly into a storm sewer system, usually found along roadways or in parking lots. Storm Sewer System means a means a conveyance, or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains designed or used for collecting or conveying stormwater. This does not include systems which are part of a combined sewer or Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2. Stormwater means that portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a stormwater drainage system into a defined surface waterbody, or a constructed infiltration facility. Stormwater Management Manual (SWMM) or Manual means the technical Manual published by Ecology for use by local governments that contain descriptions of and design criteria for BMPs to prevent, control, or treat pollutants in stormwater. Stormwater Pollution Prevention Plan (SWPPP) means a documented plan to implement measures to identify, prevent, and control the contamination of point source discharges of stormwater. Surface Waters of the State includes lakes, rivers, ponds, streams, inland waters, salt waters, and all other surface waters and water courses within the jurisdiction of the State of Washington. Temporary Stabilization means the exposed ground surface has been covered with appropriate materials to provide temporary stabilization of the surface from water or wind erosion. Materials include, but are not limited to, mulch, riprap, erosion control mats or blankets and temporary cover crops. Seeding alone is not considered stabilization. Temporary stabilization is not a substitute for the more permanent “final stabilization.” Total Maximum Daily Load (TMDL) means a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet state water quality standards. Percentages of the total maximum daily load are allocated to the various pollutant sources. A TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. The TMDL calculations must include a "margin of safety" to ensure that the waterbody can be protected in case there are unforeseen events or unknown sources of the pollutant. The calculation must also account for seasonable variation in water quality. Construction Stormwater General Permit Page 54 Transfer of Coverage (TOC) means a request for transfer of coverage under this general permit as specified by General Condition G9 of this permit. Treatment BMPs means BMPs that are intended to remove pollutants from stormwater. A few examples of treatment BMPs are detention ponds, oil/water separators, biofiltration, and constructed wetlands. Transparency means a measurement of water clarity in centimeters (cm), using a 60 cm transparency tube. The transparency tube is used to estimate the relative clarity or transparency of water by noting the depth at which a black and white Secchi disc becomes visible when water is released from a value in the bottom of the tube. A transparency tube is sometimes referred to as a “turbidity tube.” Turbidity means the clarity of water expressed as nephelometric turbidity units (NTUs) and measured with a calibrated turbidimeter. Uncontaminated means free from any contaminant. See definition of “contaminant” and WAC 173-340-200. Waste Load Allocation (WLA) means the portion of a receiving water’s loading capacity that is allocated to one of its existing or future point sources of pollution. WLAs constitute a type of water quality based effluent limitation (40 CFR 130.2[h]). Water-only Based Shaft Drilling is a shaft drilling process that uses water only and no additives are involved in the drilling of shafts for construction of building, road, or bridge foundations. Water quality means the chemical, physical, and biological characteristics of water, usually with respect to its suitability for a particular purpose. Waters of the State includes those waters as defined as "waters of the United States" in 40 CFR Subpart 122.2 within the geographic boundaries of Washington State and "waters of the State" as defined in Chapter 90.48 RCW, which include lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and water courses within the jurisdiction of the state of Washington. Well means a bored, drilled or driven shaft, or dug hole whose depth is greater than the largest surface dimension. (See Injection well.) Wheel Wash Wastewater means any water used in, or resulting from the operation of, a tire bath or wheel wash (BMP C106: Wheel Wash), or other structure or practice that uses water to physically remove mud and debris from vehicles leaving a construction site and prevent track- out onto roads. When stormwater comingles with wheel wash wastewater, the resulting water is considered wheel wash wastewater and must be managed according to Special Condition S9.D.9. Construction Stormwater General Permit Page 55 APPENDIX B – ACRONYMS AKART All Known, Available, and Reasonable Methods of Prevention, Control, and Treatment BMP Best Management Practice CESCL Certified Erosion and Sediment Control Lead CFR Code of Federal Regulations CKD Cement Kiln Dust cm Centimeters CTB Cement-Treated Base CWA Clean Water Act DMR Discharge Monitoring Report EPA Environmental Protection Agency ERTS Environmental Report Tracking System ESC Erosion and Sediment Control FR Federal Register LID Low Impact Development NOI Notice of Intent NOT Notice of Termination NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Unit RCW Revised Code of Washington SEPA State Environmental Policy Act SWMM Stormwater Management Manual SWPPP Stormwater Pollution Prevention Plan TMDL Total Maximum Daily Load UIC Underground Injection Control USC United States Code USEPA United States Environmental Protection Agency WAC Washington Administrative Code WQ Water Quality WWHM Western Washington Hydrology Model Appendix F 303(d) Category 1 Water (1 listing) Category 1 Sediment (28 listings) 1 WQ std found high nitrate priority area Appendix G Contaminated Site Information https://apps.ecology.wa.gov/gsp/CleanupSiteDocuments.aspx?csid=4520 Lf520 WORKSHEETl SUMMARY SCORE SHEET Site Name/Location (City, County, Section/Township/Range, FS ID): Former Scott Paper Mill Anacortes Skagit County Parcels P32910, P32960, Pl14718, P32866, P118626, Pl18627, P32948, Pll 8625, P32963, P32913,P32929,P32965,P32916,P32915,P32966,P32967,P32968,P32941,P32964 NW Y-i Section 19, Township 35 North, Range 2 East (former Scott Paper Mill Location), SW Y-i NW Y-i Section 18, Township 35 North, Range 2 East (former location Scott Paper Mill Diffuser to Guemes Channel) Latitude 48 30 36.1 DMS, Longitude 122 36 25.7 DMS (former mill site) FSID: 8122259 Owners/PLPs: Kimberly-Clark Corporation Environmental Programs Ms. Cynthia L. Jernigan, Manager 1400 Holcomb Bridge Road Roswell, GA 30076 Port of Anacortes Daniel H. Stahl, Executive Director First and Commercial Avenue P.O. Box297 Anacortes, WA 98221 Parcels owned: P32910,P32960,Pl14718,P32866 Shared Healthcare Systems, Inc. Mr. Leo Watterson, CEO/President 1601 RAvenue Anacortes, WA 98221 Parcels owned: Pl 18626, Pl 18627 Northwest Educational Service District District #189 Superintendent Jerry Jenkins 1601 RAvenue Anacortes, WA 98221 Parcels owned: P32948 Site Description/History Current Site Description Anacortes Concept LLC 4912 Heather Dr. Anacortes, WA 98221 Parcels owned: P118625 MJB Properties Gary M. Merlino, Managing Partner 9125 -10th Avenue South Seattle, WA 98108 Parcels owned: P32963,P32943,P32913,P32929,P32965, P32916,P32915,P32966,P32967,P32968,P32941 William L. Snelson, et. al. c/o Lorren K. Levorsen 2691 Douglas Road Ferndale, WA 98248 Parcels owned: P32964 The Former Scott Paper Mill site encompasses several parcels of property in Anacortes, Washington. The main site, the former location of the mill operations, is located to the east of "Q" Avenue between 14th and 201h Streets. It is referred to in documents as Parcel !(Skagit County Parcel P32910), Parcel 2 (Skagit County Parcels Pl 18625, P32948, Pl 18626, Pl 18627,P32964), and Parcel 3 (Skagit County Parcel P32960), and MJB North (refer to Attachment I for Skagit County Parcel locations). Parcel 1, 2, and 3 comprise the northern portion of the property owned mostly by the Port of Anacortes and Northwest Educational Service District. Parcels 1, 2, and 3 are approximately 15 acres in area. Parcel 3 is in the northeast portion of the site and is currently occupied by a 1 Yi acre waterfront park. Parcel 2 contains a building housing Shared Health Care Systems business and the Northwest Educational Service District offices, and a health club. A portion of Parcel 2 and all of Parcel 1 to the west are open grassland. About four of the 15 acres of Parcels 1, 2, and 3 are paved or covered with buildings. The southern half of the main Former Scott Paper Mill site, known as MJB North (approximately 20 acres), is mostly open, unpaved land. The property is largely fenced an4 appears to be used only for some storage of boat hulls and other large items. One large former assembly building exists on the property and appears to be currently vacant. Parcels 1, 2, and 3 are currently zoned for Commercial Marine Services. This type of zoning allows for a variety of commercial and retail enterprises and the possibility for multifamily housing, motels, and hotels with a special use permit. The southern portion of the property, MJB North, is zoned industrial. The site is bordered to the north by Cap Sante Marina and Figalgo Bay, to the east by Fidalgo Bay, to the south by largely vacant industrial property and Anacortes Marina and to the west by a variety of commercial properties. The portion of the site bordering Fidalgo Bay has a bank approximately 6-10 feet high and in places there is significant erosion of this bank into the bay. A mix of single family and multi family housing is located within a one mile radius from the property with a population from the 2000 census of 4920. The site and the surrounding area are served by City of Anacortes for water and sewer. Storm water from the site drains to city storm sewers and to Fidalgo Bay. Fidalgo Bay is a commercial and private crabbing area. Eel grass beds exist in the bay sporadically near the site and heavily approximately 1 Yz to 2 miles to the southeast of the site. A small marine wetland on the National Wetlands Inventory is located at the northern extent of the bay approximately 2000 feet to the north of the site. Refer to Attachment I for a map of the current site features and parcel lines. Included in the main site, the former mill location, are the former locations of a shoreline outfall pipe from the mill and a later diffuser pipe that extended into Guemes Channel from the mill. Both were located near the terminus of Q A venue and the Channel. This property is Skagit County Parcel P32903 and is a narrow tideland parcel owned by the Port of Anacortes and occupied by Dakota Creek Industries for their boat building and repair business. The Port of Anacortes reports that the diffuser pipe is no longer present at this location. Site History The history of the mill site is well documented in the 1999 report by ThermoRetec Consulting Corporation titled "Remedial Investigation and Feasibility Study for Soils at Parcel 2 of the Former Scott Paper Company Mill Site". I will briefly summarize the information from that report. The property was first recorded being developed in 1890 and . used for a lumber mill. It appears that wood waste and other refuse were used to fill in the tidelands around the mill. The mill operated under various owners until 1914 when it was closed during World War I. In 1918 the mill was re- opened and produced finished lumber and boxes until it was destroyed by a fire in 1924. After re-opening in 1925, the mill is reported to have doubled the infill of tidelands on the property. Part of the mill property was leased to Puget Sound Pulp Company for the construction of a pulp mill. Twenty to forty tons of pulp per day were produced using an acid sulfite process. Power for the lumber and pulp mills was mainly supplied by the burning of hog fuel until the mill converted to petroleum use in the 1950s. Small bleach tanks in the digester room are noted in maps from 1925. Wastes, including spent sulfite liquor, were discharged directly to Fidalgo Bay. The pulp mill was purchased by Scott Paper in 1940 and the mill was known as Coos Bay Pulp Company. By 1950 three oil storage houses existed on the property as well as a tank farm. In 1951 the mill was converted to produce pulp for tissue paper. Pulp was sent to Everett for final processing into paper. In 1952 the mill began using an ammonia based sulfite process to digest the wood. The lumber mill buildings were demolished by Scott and pulp bleaching facilities were installed in 1955. The bleaching facility doubled the amount of waste water discharged from the site. Records show that in 1952 a wooden pipeline was installed down Q Avenue to divert most of the mill effluent from Fidalgo Bay to Guemes Channel. A 20,000 gallon unlined surge pond was built at this time to hold effluent until tides ebbed in Guemes Channel. The first permit for waste water discharge was issued in 1955 by the Washington Pollution Control Commission (WPCC). A knots and tailings pond was constructed in 1959 to settle solids out of wastes from four areas of the mill including post bleaching processes. In 1964 due to requirements from the WPCC all effluents except for saltwater used for cooling the acid plant were diverted to the Guemes Channel outfall. All wastes were converted back to Fidalgo Bay ifthe pumps at the surge pond were shut down or failed. In 1970 this pipeline was reconstructed to discharge through a diffuser 680 feet beyond the outer harbor line into the Guemes Channel currents. Scott records reportedly showed the average discharge volume per day for the Guemes Channel diffuser was 6.89 million gallons around 1970. Significant fill was still occurring on the property into the 1970s from barking wastes produced by the mill. In 1975 the EPA filed suit against Scott for violations to the Clean Water Act. In 1978 Scott closed the Anacortes mill because profits from the mill could not justify the expense of the necessary mill upgrades required for pollution control. A copy of the locations of the former mill site features is reproduced for this report from ThermoRetec (Attachment II). The mill property was divided and purchased in part by the Port of Anacortes and in part by the Snelson Anvil Company in 1978 and 1979. Pulp tailings were removed from the mill site (from the pond area and a tailings pile) by Scott under the purchase agreement with the Port. Tailings were taken to Dahlstedt property in Skagit County for commercial use. Remaining mill buildings were demolished by the Port in the 1980s on northeastern quadrant of the former mill property. Anvil Corporation is reported to have replaced much of the wood waste fill on MJB North property in 1982 with granular fill in layers. The Cap Sante Marina, owned by the Port, was expanded with a dredging operation in 1983 and sediments containing wood waste and total volatile organic compounds exceeding open water disposal criteria were placed on part of the former tailings pond. The mill site remained largely vacant until the Port constructed a log yard on the northern portion of the site in the early 1990s. At that time bark piles were removed from the north western property and replaced with soil fill taken from a project at the Anacortes WWTP. The dredged sediments were re-graded in the tailings pond and geotextile fabric and pit run were added to the surface of the pond. By 1994 the log yard had closed and the Port was looking at a variety of other uses for the property. They obtained clean sands from the 1994 dredging of the Swinomish Channel to use as fill and preload on a large central portion of Parcels 1 and 2. In 1995 the northeastern 1 Yi acres of the site (Parcel 3) were developed by the Port into a park. As a part of this developpient the soils in this area were covered with 6 to 12 inches of topsoil. A building and public float were erected for the park. In 1998 Sun Systems (now Shared Health Care Systems) purchased Parcel 2 for the development of an office complex. Some site remediation occurred as part of this purchase agreement. This will be discussed below. In 2001 a building housing a health club was constructed to the west of this on Parcel 2. Site Evaluations MJB Properties site was placed on the Confirmed and Suspected Contaminated Sites list in 1995 based on sediment sample data provided by DNR in 1992 and historical use of the site as a pulp mill and other industrial uses to the south. This listing included the MJB North property of the former mill site as well as other property to the south of the mill site. In 1997 the remainder of the former Scott Paper Mill site was added by Ecology to the Confirmed and Suspected Contaminated Sites list. Property owners have been under on-going discussions and negotiations with the Department of Ecology since these site listing concerning contamination issues and remediation options on the property. Kimberly-Clark, the current parent company of Scott, has been brought in to discussions as a potentially liable party. . A number of investigations have occurred on and around the former mill site since the 1980s. This assessment largely relies upon a summary of sample data contained in the recent report "Comprehensive Evaluation of Existing Data- Former Scott Paper Mill Site -Anacortes, Washington" prepared by Anchor Environmental, L.L.C. for Kimberly- Clark Corporation, Port of Anacortes, and MJB Properties, Inc in March of 2002. Substances of potential concern on the property due to past use include diesel fuel and heavy oils, metals including lead, mercury, and arsenic, persistent chlorinated compc;mnds such as PCBs and dioxin, combustion by-products such as P AHs, and semi-volatile organic compounds. The full Anchor report should be consulted by anyone seeking a complete data summary. Highlights only will be presented here in Attachment III. Concentration ranges or maximums are only presented for the samples exceeding a Sediment Quality Standard or a MTCA Method A or B clean up standard. Most sampling has occurred around the former mill structures on Parcel 2, Parcel 3 in the park area, and on the northwest quadrant ofMJB North. Th~ Anchor report provides maps showing locations of samples and results for substances of highest concern. Hydrogen sulfide and methane releases related to the decomposition of the wood waste fill and pulp wastes at the mill site and in the sediments could be significant at the site, particularly during excavation of soils or sediments. There has been no documented monitoring for methane at the site. Very limited monitoring for hydrogen sulfide by Northwest Air Pollution Authority in 1993 near Seafarer's Park (Parcel 3) showed levels of lppm. In 1995 Hart Crowser tested air for hydrogen sulfide from 6 monitoring wells located in the area of the park on Parcel 3 and one in the sediment off Parcel 3. The sediment well had a level of7 ppm hydrogen sulfide and one upland well had a level of 2 ppm. Seasonal variation is likely in the levels found as past samples of these wells taken in winter yielded no detectable hydrogen sulfide. Hydrogen sulfide can be naturally present in tidelands from the decay of organic matter such as seaweed but it is reasonable to assume at this site, given the amount of wood waste fill on the property, that some of the hydrogen sulfide released in the sediments and released into wells in the uplands would be due to wood and pulp waste decay from the former mill. Excavation of soils heavily contaminated with petroleum occurred on Parcel 2 in two areas in 1999 as a part of the development of the site under a Cleanup Action Plan reviewed and approved by Ecology. Approximately 3500 tons of soils were removed from the vicinity of the former tank farm and taken off site for treatment. Sample results listed above do not include these excavated areas. At this same time a 200 foot section of sheet piling wall was installed to a depth of 26 feet below ground surface along the shoreline of Parcel 2 to prohibit further transport of contamination to surface water and sediments. No further remediation activities have been reported on the Former Scott Paper Mill site since this time. Current negotiations are underway with Ecology with the intent of developing a Cleanup Action Plan or Plans for the remainder of the site. Four investigations from 1985 to 2001 have evaluated sediment quality near the former mill outfall and diffuser pipe locations to Guemes Channel. These investigations were not targeted at assessing contamination from the mill effluent but rather focused on use of the property as a ship building and repair yard for Dakota Creek Industries. An additional potential source of contamination near the former mill outfall is the City of Anacortes sanitary sewer outfall. Landau Associates summarized findings from the four investigations in the 2003 report "Sediment Data Assessment Dakota Creek Industries Shipyard Facility, Anacortes, Washington." Most sample locations were within an area referred to as the Dakota Creek Industries Basin, a working harbor that is directly to the east of the former outfalls for Scott Paper Mill. Arsenic, copper, mercury, zinc, some semi-volatile compounds including P AHs, and tributyltin were detected in some samples at levels that exceeded Sediment Quality Standards. Dioxins were not analyzed for in any samples. PCBs were analyzed for in some samples but not detected above Sediment Quality Standards. Sediment dredging occurred in the area of the former mill diffuser in the late 1980s as a part of the installation ofa boat lift for Dakota Creek Industries but no activities directed toward remediation of contaminated sediments have occurred. Special Considerations Hydrogen sulfide is included in the scoring for the air route. Hydrogen sulfide can have natural sources in tidelands, however, th.is is a conservative scoring of relative risk at the site and there is a high likelihood, given the amount of wood waste present at the site, that hydrogen sulfide is being released related to this decaying wood waste from the mill. A release to air could not be scored for this route because there is no adequate documentation of background levels of hydrogen sulfide on similar nearby beach areas that would not be impacted by wood waste from the mill or other source. PCBs were not able to be included in the scoring for the Air/Human Health route due to a lack of appropriate toxicity values. For each route there were more than six substances of concern. Substances included in scoring were chosen by the number, significance of exceedences, and presence in uplands as well as sediments. In each route, the toxicity scored at the maximum values and would not have been affected by including all substances of concern. Sediment data from near the mill outfall to Guemes Channel indicate a number of substances of concern including some not found at the main mill site on Fidalgo Bay. These substances are noted in Attachment II and on Worksheet 2 but were not included in the scoring because the toxicity values using substances at the main mill site were already the maximum value and the substances may be from the shipyard activities or the city sewer outfall and unrelated to mill activities. Route Scores Surface Water/Human Health: 19.4 Surface Water/Environment: 41.6 Air/Human Health: 22.0 Air/Environmental: 29.6 Ground Water/Human Health 43.6 Overall Rank 2 Attachment II-Summary of Significant Sample Data Former Scott Paper Mill Location( data from Anchor, 2002) Substance Matrices Evaluated Concentration Range of Exceedences Antimony Surface and subsurface soils, surface Surface and subsurface soil: _Max 101 mg/kg sediments, groundwater Arsenic Surface and subsurface soils, surface Surface and subsurface soil: 23 -142 mg/kg sediments, groundwater Groundwater: Max 27 ug/L Cadmium Surface and subsurface soils, surface 5 surface and subsurface soil samples exceeded 4 mg/kg sediments, groundwater (screening level for ecological protection) Copper Surface and subsurface soils, surface 2 subsurface soil samples exceeded 2960 mg/kg (screening sediments, groundwater level) Lead Surface and subsurface soils, surface Subsurface soil: 390 -6428 mg/kg sediments, groundwater Surface sediments: Max 1020 mg/kg Groundwater: Max 37 ug/L Mercury Surface and subsurface soils, surface Surface and subsurface s_oil: Max 29 mg/kg sediments, groundwater Max sediment 0.88 mg/kg Thallium Surface and subsurface soils, surface Subsurface soil: Max 51 mg/kg sediments, groundwater CPAHs Surface and subsurface soils, Surface and subsurface soil: 119.3 -6670 ug/kg groundwater PCBs Surface and subsurface soils, surface Subsurface soil -6500 and 23800 ug/kg sediments, groundwater Surface sediments -16667 -107692 ug/kg-oc Dioxin Surface and subsurface soils, surface Subsurface soil: 8.4 -61.7 ng/kg TEQ sediments, groundwater Diesel Surface and subsurface soils, Subsurface soil: 3000 -42,000 mg/kg Groundwater Summary of Significant Sediment Sample Data, Near Former Scott Paper Mill Outfall to Guemes Channel (Landau, 2003) Substance Matrices Evaluated Maximum Detected Arsenic Surface sediments 82.6 mg/kg -in Dakota Creek Industries Basin Copper Surface sediments 1,440 mg/kg -in Dakota Creek Industries Basin Mercury Surface sediments 0.43 mg/kg -in Dakota Creek Industries Basin Zinc Surface sediments 665 mg/kg -in Dakota Creek Industries Basin Tributyltin Surface sediments 11,748 ug/kg -bulk sample in Dakota Creek Industries Basin LPAHs Surface sediments 522 mg/kg -in Dakota Creek Industries Basin HPAHs Surface sediments 1,967 mg/kg -in Dakota Creek Industries Basin Bis(2-ethylhexyl)phthalate Surface sediments 7 5 mg/kg -in Dakota Creek Industries Basin Dibenzofuran Surface sediments 16 mg/kg -in Dakota Creek Industries Basin Butylbenzylphthalate . Surface sediments 20 mg/kg -near former mill outfall 1. SURFACE WATER ROUTE WORKSHEET2 ROUTE DOCUMENTATION List those substances to be considered for scoring: Source:~ Arsenic, Lead, Mercury, PCBs, CP AHs, Antimony, Tributlytin, Bis(2-ethylhexyl)phthalate Dibenzofuran, Butylbenzylphthalate Explain basis for choice of substance(s) to be used in scoring. Substances measured in surface soil above MTCA Unrestricted Land Use Clean Up Standards, or substances measured in surface sediments greater than Sediment Quality Standards up to the six substances most closely associated with the mill. List those management units to be considered for scoring: Contaminated surface soil and sediments. Explain basis for choice of unit to be used in scoring. Documented surface soil and sediment contamination available to surface water. 2. AIRROUTE List those substances to be considered for scoring: Arsenic, Lead, Mercury, PCBs, CP AHs, Antimony, Hydrogen sulfide, Methane Explain basis for choice of substance(s) to be used in scoring. Substances measured in surface soil above MTCA Unrestricted Land Use Clean Up Standards, or substances measured in surface sediments greater than Sediment Quality Standards, or substances detected in air monitoring. Substances actually scored were those that had appropriate toxicity values available for the route. PCBs did not have inhalation human toxicity values available .. List those management units to be considered for scoring: Surface soil, surface sediments, and air. Explain basis for choice of unit to be used in scoring. Documented surface soil and surface sediment contamination, documented release to air. Source:-1.,2 Source: 2.4, 8 Source:~ 3. GROUND WATER ROUTE WORKSHEET 2 (CONTINUED) ROUTE DOCUMENTATION List those substances to be considered for scoring: Arsenic, CP AHs, Diesel, Dioxin, Lead, PCBs, Mercury, Antimony Explain basis for choice of substance(s) to be used in scoring. Substances measured in groundwater above MTCA clean up standards or substances found in subsurface soils at levels exceeding MTCA protection of groundwater standards. Six substances with most significant exceedences were actually scored. List those management units to be considered for scoring: Contaminated groundwater, contaminated subsurface soil. Explain basis for choice of unit to be used in scoring. Documented groundwater contamination, documented subsurface soil contamination. Source:~ Source:~ WORKSHEET4 SURFACE WATER ROUTE 1.0 SUBSTANCE CHARACTERISTICS 1.1 Human Toxicity 1. Arsenic 2. Lead 3. Mercury 4.PCBs 5. Antimony 6.CPAHs 'Potency Factor 1.2 Environmental Toxicity Substance I.Arsenic 2.Lead 3.Mercury 4.PCBs 5.Antimony 6.CPAHs Drinking Water Standard (ug/l) Val. 10 8 5 8 2 8 0.5 10 3 8 0.2 10 ( ) Freshwater (X) Marine Acute Water Quality Criteria Acute Toxicity (mg/kg-bw) Val. 763(rat) 5 x x x x 1315(rat) 3 7(rat) 10 50(rat) 10 Chronic Toxicity (mg/kg/day) Val. 0.001 5 x x 0.0003 5 x x 0.0004 5 x x Carcino- genicity WOEPF* Val. A 1.75 7 B2 X X x x x B2 7.7 6 x x x B2 12 7 Source: 2,8,9 Highest Value:___lQ (Max.=10) +2 Bonus Points?---±2. Final Toxicity Value 12 (Max.=12) Non-human Mammalian Acute Toxicity f!!gil) Value (mg/kg) Value Source:~ Value:-1.Q (Max.=10) 69 6 140 4 2.1 8 10.0 8 x x 7.0(rat) 10 300 4 1.3 Substance Quantity:--"l=.9_----"'-1-"--0-=a=cr=e"'-s ______ _ Source: 2,4,8,17 Value: 9 (Max.=10) Explain basis: estimated area from surface soil sampling 2.0 MIGRATION POTENTIAL 2.1 Containment WORKSHEET 4 (CONTINUED) SURFACE WATER ROUTE Explain basis: Uplands partially capped with clean fill however entire site not Source: 1,2.3.4.8 Value:__1 Capped or contained. In addition bank above bay is eroding in places. Score as contaminated Soil at surface with ineffectively maintained run-on/run-off control. 2.2 Sutface Soil Permeability: In sediment. adjacent to surface water 2.3 Total Annual Precipitation:_2=5~·~7 _____________ ·=in=c=h=e~s 2.4 Max. 2-Yr/24-hour Precipitation:~l.=5 __________ ~m=· =c=he~s 2.5 Flood Plain: Not in flood plain 2.6 Terrain Slope: Adjacent to sutface water 3.0 TARGETS 3 .1 Distance to Sutface Water: 0 ft ·-~~-------------~ 3.2 Population Served within 2 miles (See WARM Scoring Manual Regarding Direction): ,._PO~P""'·-=~0 ___ =~0 _________ _ 3.3 Area Irrigated within 2 miles 0.75"'1no. acres= (Refer to note in 3.2.): 0.75"'10 =0.75( 0 )= 0 3.4 Distance to Nearest Fishery Resource: Fidalgo Bay< 1000 ft 3.5 Distance to, and Name(s) of, Nearest Sensitive Environment(s) Fidalgo Bay< 1000 ft 4.0 RELEASE Explain basis for scoring a release to surface water: Present in surface sediments Source:u_ Value:_.1 (Mru<,=7) Source:UQ___ Value:___l (Mru<.=5) Source:_8_ Value: 2 (Mru<.=5)- Source: 2,8,17 Value:__!! (Mru<.7'2) Source: 1.2.8 Value: 5 (Mru<.=5)- Source:..1..2....8_ Value:..!Q (Mru<.=10) Source: 8,1116.17 Value:_Q (Mru<.=75) Source: f,8,11 Value: 0 (Mru<.=30) - Source:..1..2....8_ Value: 12 (Mru<.=12)- Source: 1,2,8 Source: 2,5,8 ·Value: 12 (Max.=12)- Value: 5 (Mru<.=5) 1.0 SUBSTANCE CHARACTERISTICS WORKSHEETS AIR ROUTE I. I Introduction (WARM Scoring Manual) -Please review before storing 1.2 Human Toxicity Substances I.Arsenic 2.Lead 3.Mercury 4.Antimony 5.cPAHs 6.Hydrogen sulfide 'Potency Factor Air Standard (ug/m3) Val. 0.00023 IO 0.05 IO 0.03 10 1.7 9 0.0006 IO 0.9 IO Acute Toxicity (mg/m3) Val. x x x x x x x x x x 335-587 (rat) IO 1.3 Mobility (Use numbers to refer to above listed substances) 1.3.I Gaseous Mobility Vapor Pressure: 6= 14,469 mmHg 1.3.2 Particulate Mobility Carcino- genicity Chronic Toxicity (mg/kg/day) Val. x x x x WOE PF* Val. 0.000085 8 x x x x 0.003 3 Source: 2,4,8 Highest Value:..lQ (Max.=10) +2 Bonus Points? +2 Final Toxicity Value: I2 (Max.=12) A 50 9 x x x x x x x x x x x x x x x Source: 7,8 Value: 4 (Max.=4) J Soil type: coarse sand, gravel, silt (all fill soils on tidelands) Erodibility: 73 (score as coarse sand) Source: 2,8 Value: I (Max.=4) Climatic Factor:~l-~1=0 ____ _ 1.4 Highest Human Health Toxicity/Mobility Matrix Value (from Table A-7) equals Vapor= I0/4 = 20, Particulate= 12/1 =6 Final Matrix Value: 20 1.5 Environmental Toxicity/Mobility Substance I.Arsenic 2.Lead 3.Mercury 4.Antimony 5.CPAHs 6.Hydrogen sulfide Non-human Mammalian Inhal. Toxicity (mg/m3) x x x x x 335 -587 (rat) Acute Value Mobility (mmHg) x x x x x x x x x x 10 14,469 Highest Environmental Toxicity/Mobility Matrix Value (From Table A-7) equals Final Matrix Value:---1!!: (Max.=24) (Max.=24) Source: 2,4,7,8 (Table A-7) Value Matrix Value x x x x x 4 20 WORKSHEET 5 (CONTINUED) AIR ROUTE 1.6 Substance Quantity:_~l~.5~5--7~·~8~a~c~re=s ________________ Source: 2.4.8.17 Value: 6 · Explain basis: estimate quantity from surface soil sampling (Max.=IO) - 2.0 MIGRATION POTENTIAL 2.1 Containment: Parts of site capped with clean soil or paved but not entire site. Source: 1,2,3,4,5,8 Value: 5 Site has eroding shoreline in parts. Site has contaminated uncontained surface sediments. (Max.=IO) 3.0 TARGETS 3.1 Nearest Population:_<_l"'-'0"-.00'-"0'"-'fi=e=et"-------------------Source:__L_[_ Value: 10 (Max~ 3.2 Distance to, and Name(s) of, Nearest Sensitive Environment(s) . Wetlands approximately 2000 feet ' Source:Ji,JL Value: 5 (Max.=7) 3.3 Population within 0.5 miles:~.Y~12~3~0~P~O""P~·=~3~5 ______________ Source:Jhl.Q_ Value: 35 (Max.~ 4.0 RELEASE Explain basis for scoring a release to air: Hydrogen sulfide measured at site but no Source:_4'-=8 __ Value: 0 documented background levels available to compare if over 3 times. (Max~ WORKSHEET6 GROUND WATER ROUTE 1.0 SUBSTANCE CHARACTERISTICS 1.1 Human Toxicity Substance I.Arsenic 2.CPAHs 3.Diesel 4.Dioxin 5.Lead 6.PCB *Potency Factor Drinking Water Standard fugfil Val. 10 8 0.2 10 160 4 0.00005 10 5 . 8 0.5 10 Acute Toxicity (mg/kg-bw) Val. 763(rat) 5 50(rat) 10 490(rat) 5 x x x x 1315(rat) 3 1.2 Mobility (Use numbers to refer to above listed substances) Cations/ Anions: 1 = 3 · 2= · 3= · 4= · 5= 2 · 6=. OR Solubility( mg/I): 1 = · 2= 0 · 3= 1 4= 0 · 5= 6=0 . 1.3 Substance Quantity: 500,000 -1,000,000 cubic yards Chronic Toxicity (mg/kg/day) Val. 0.001 5 x x 0.004 3 x x x x x x Carcino- genicity WOE PF* Val. A 1.75 7 B2 12 7 B2 X X B2 150000 8 B2 X X B2 7.7 6 Source: 2,6,8,9 Highest Value:_lQ (Max.=10) +2 Bonus Points? +2 Final Toxicity Value:.,..ll (Max.=12) Source:~8=9 __ Va~~;.=~ Explain basis: estimate from sampling of subsurface soil (area estimate) Source: 1,2,8.17 Value:.J! (Max.= IO) 2.0 MIGRATION POTENTIAL 2.1 Containment Explain basis: release to groundwater. not capped throughout site Source:~ Value: 10 (Max.=10)- 2.2 Net Precipitation: _________ ~l_l~.O __ ~in~c~h~es~---Source:JhlQ__ Value: 2 (Max.=5)- 2.3 Subsurface Hydraulic Conductivity:_s_ilt~,_san~d~y_s_il_t ________ Source:_b_!L__ 2.4 Vertical Depth to Ground Water: 0 -25 feet observed at site Source:_lL Value: 3 (Max.=4) Value: 8 (Max.=8)- 3.0 TARGETS WORKSHEET 6 (CONTINUED) GROUND WATER ROUTE 3.1 Ground Water Usage: private supply, alternative source available Source: 8,11,12 Value:__1 (Max.= IO) 3.2 Distance to Nearest Drinking Water Wel1:_5~0~0~0_-~10~0~0~0~ft~ _______ Source: 8.12.17 Value: 1 (Max.=5)- 3.3 Population Served within 2 Miles:~-V4~5~=~7 ______________ Source: 8.12 3.4 Area Irrigated by (Groundwater) Wells within 2 miles:_0_.7~5~-V~n_o~.a~c_re~s~=_O ____________ Source: 1,8,11 4.0 RELEASE Explain basis for scoring a release to ground Source:-=2=~8"--- water: documented release to ground water of arsenic. lead, and diesel SOURCES USED IN SCORING Value: 7 (Max.=50)- Value: 0 (Max.= JOO) Value: 5 (Max.=5) 1. Skagit County Health Department" Field Notes from Site Hazard Assessment Site Visit, January 12, 2004. 2. Anchor Environmental, L.L.C. et al, Comprehensive Evaluation of Existing Data Former Scott Paper Mill Site Anacortes, Washington, March 2002. 3. Applied Geotechnology Inc., Site Assessment, SL Resources Inc. Property, Anacortes, Washington, September 11, 1987. 4. Garry E. Horvitz, P.E., Letter RE: Summary of Results of Hydrogen Sulfide Monitoring Cap Sante South Uplands, October 10, 1996. 5. Landau Associates, Sediment Data Assessment Dakota Creek Industries Shipyard Facility Anacortes, Washington, February 21, 2003. 6. ThermoRetec Consulting Corporation, Remedial Investigation and Feasibility Study for Soils at Parcel 2 of the Former Scott Paper Company Mill Site Anacortes, Washington, January 8, 1999. 7. U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances Disease Registry, Toxicological Profile for Hydrogen Sulfide, July, 1999. 8. Washington Department of Ecology, WARM Scoring Manual, April, 1992. 9. Washington Department of Ecology, Toxicology Database for Use in Washington Ranking Method Scoring, January, 1992. 10. National Weather Service, Washington Climate Data. 11. Washington Department of Ecology, Water Rights Information System (WRIS), 1997. 12. Washington Department of Ecology, Well Logs. 13. USGS 7.5 minute Topographical Quadrangles -Anacortes South. 14. Washing Department of Health Public Water Supply Data. 15. Skagit County Planning and Permit Center, Critical Areas Maps. 16. EPA Geographic Query Information System, Scott Paper Mill Site, January 2004. 17. Skagit County Mapping, SkagitView Version 3.0, December 2003. Cleanup Site ID: 4520 Facility/Site ID: 8122259 Site Page Site Documents View Map Cleanup Site Name: Scott Paper Mill Alternate Names: CITY OF ANACORTES, DAKOTA CREEK INDUSTRIES, MJB PROPERTIES, INC., Scott Paper Mill, Scott Paper Mill Former LOCATION Address: 17TH-20TH ST & R AVE City: ANACORTES Zip Code: 98221 County: Skagit UST ID: N/A Latitude: 48.50748 Longitude: -122.61028 WRIA: 3 Legislative District: 40 Congressional District: 2 TRS: 35N 2E 19 DETAIL Status: Construction Complete- Performance Monitoring Site Manager: Park, Hun Seak Responsible Unit: Statute: MTCA Site Rank: 2 - Moderate-High Risk Is PSI site? Past VCP?Current VCP? Active Institutional Control? NFA Received? NFA Date: NFA Reason: CLEANUP UNITS Cleanup Unit Name Unit Type Unit Status Resp Unit Unit Manager Current Process Scott Paper Mill Former Sediment Construction Complete- Performance Monitoring HQ Park, Hun Seak Ecology-supervised or conducted Scott Paper Mill Former Upland Construction Complete- Performance Monitoring HQ Park, Hun Seak Ecology-supervised or conducted Institutional Control documents may be available under the 'Site Documents' link at the top of the page. For more details on Institutional Controls, please see the Environmental Covenants Registry List. ACTIVE INSTITUTIONAL CONTROLS Instrument Type Restriction Media Restrictions/Requirements Date Recording Number Recording County Tax Parcel Environmental Covenant Soil Restrict Land Use, Prohibit Soil Disturbance 11/20/2013 201311200045 Skagit P32963; P32965 MEDIA AFFECTED MEDIA & CONTAMINANTS Key: B - Below Cleanup Level S - Suspected RA - Remediated-Above RB - Remediated-Below C - Confirmed Above Cleanup Level R - Remediated Contaminant Soil Groundwater Surface Water Sediment Air Bedrock Conventional Contaminants, Inorganic C Conventional Contaminants, Organic C S Dioxin/Dibenzofuran Compounds C C Metals Priority Pollutants C C C C S Other Deleterious Substances C Petroleum Products-Unspecified C S S C S Polychlorinated biPhenyls (PCB)C S S C S Polycyclic Aromatic Hydrocarbons C C C Brownfield? No N/A N/A Headquarters Yes No No No Yes Glossary Toxics Cleanup Program Page 1 of 2Report Generated: 7/16/2019 Cleanup Site Details Cleanup Site ID: 4520 SITE ACTIVITIES Activity Status Start Date End Date/ Completion Date Order/Decree/Amendment In Process Order/Decree/Amendment In Process Site Discovery/Release Report Received Completed 10/24/2003 Site Hazard Assessment/Federal Site Inspection Completed 11/3/2003 12/5/2004 Hazardous Sites Listing/NPL Completed 12/5/2004 Remedial Investigation and/or Feasibility Study Completed 9/6/2006 11/28/2008 Cleanup Action Plan Completed 12/1/2008 5/29/2009 Cleanup - Construction Completed 12/1/2011 9/24/2012 Cleanup Action - Engineering Design Completed 12/1/2011 5/1/2012 Toxics Cleanup Program Page 2 of 2Report Generated: 7/16/2019 Cleanup Site Details Cleanup Site ID: 4520 Appendix H Engineering Calculations Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.020 Channel Slope 0.00500 ft/ft Normal Depth 1.00 ft Left Side Slope 2.00 ft/ft (H:V) Right Side Slope 2.00 ft/ft (H:V) Bottom Width 2.00 ft Results Discharge 15.25 ft³/s Flow Area 4.00 ft² Wetted Perimeter 6.47 ft Hydraulic Radius 0.62 ft Top Width 6.00 ft Critical Depth 0.90 ft Critical Slope 0.00757 ft/ft Velocity 3.81 ft/s Velocity Head 0.23 ft Specific Energy 1.23 ft Froude Number 0.82 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 1.00 ft Critical Depth 0.90 ft Channel Slope 0.00500 ft/ft Critical Slope 0.00757 ft/ft Worksheet for Interceptor Swale - TESC 8/27/2020 4:59:39 PM Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1of1Page ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.52 Program License Number: 200410007 Project Simulation Performed on: 12/22/2020 7:06 AM Report Generation Date: 12/22/2020 7:06 AM ————————————————————————————————— Input File Name: TESC_Interceptor Swale_East.fld Project Name: MJB Anacortes Analysis Title: Interceptor Swale East T Ave Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 12 Full Period of Record Available used for Routing Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 11.773 11.773 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 11.773 11.773 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 8.723 Impervious 3.050 ---------------------------------------------- Subbasin Total 11.773 Phase 1 Interceptor Swale East ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 8.723 Impervious 3.050 ---------------------------------------------- Subbasin Total 11.773 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.062 2-Year 1.062 5-Year 1.595 5-Year 1.595 10-Year 1.916 10-Year 1.916 25-Year 3.010 25-Year 3.010 50-Year 3.653 50-Year 3.653 100-Year 3.998 100-Year 3.998 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.52 Program License Number: 200410007 Project Simulation Performed on: 12/22/2020 7:27 AM Report Generation Date: 12/22/2020 7:27 AM ————————————————————————————————— Input File Name: TESC_Interceptor Swale_North17th.fld Project Name: MJB Anacortes Analysis Title: Phase 1 Interceptor Swale North of 17th St Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 12 Full Period of Record Available used for Routing Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 5.978 5.978 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 5.978 5.978 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 5.978 ---------------------------------------------- Subbasin Total 5.978 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 5.978 ---------------------------------------------- Subbasin Total 5.978 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 0.167 2-Year 0.167 5-Year 0.316 5-Year 0.316 10-Year 0.488 10-Year 0.488 25-Year 0.982 25-Year 0.982 50-Year 1.256 50-Year 1.256 100-Year 1.547 100-Year 1.547 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.52 Program License Number: 200410007 Project Simulation Performed on: 12/22/2020 9:14 AM Report Generation Date: 12/22/2020 9:15 AM ————————————————————————————————— Input File Name: TESC_Interceptor Swale_East.fld Project Name: MJB Anacortes Analysis Title: Phase 2 Interceptor Swale East Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 12 Full Period of Record Available used for Routing Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 10.085 10.085 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 10.085 10.085 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 10.085 ---------------------------------------------- Subbasin Total 10.085 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 10.085 ---------------------------------------------- Subbasin Total 10.085 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 0.281 2-Year 0.281 5-Year 0.533 5-Year 0.533 10-Year 0.824 10-Year 0.824 25-Year 1.657 25-Year 1.657 50-Year 2.119 50-Year 2.119 100-Year 2.609 100-Year 2.609 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.50 Program License Number: 200410007 Project Simulation Performed on: 10/19/2020 8:33 AM Report Generation Date: 10/19/2020 8:33 AM ————————————————————————————————— Input File Name: TESC_Runoff into Pond.fld Project Name: MJB Anacortes Analysis Title: Phase 1 Runoff into Sediment Pond Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 60, 15 Extended Precipitation Time Series Selected Climatic Region Number: 12 Full Period of Record Available used for Routing Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 17.067 17.067 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 17.067 17.067 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 10.637 Impervious 6.430 ---------------------------------------------- Subbasin Total 17.067 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 10.637 Impervious 6.430 ---------------------------------------------- Subbasin Total 17.067 *** Point of Compliance Flow Frequency Data for 1 Hour Time Step *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.562 2-Year 1.562 5-Year 2.232 5-Year 2.232 10-Year 2.751 10-Year 2.751 25-Year 3.261 25-Year 3.261 50-Year 3.662 50-Year 3.662 100-Year 3.964 100-Year 3.964 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals *** Point of Compliance Flow Frequency Data for 15 Minute Time Step *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 4.950 2-Year 4.950 5-Year 6.477 5-Year 6.477 10-Year 8.195 10-Year 8.195 25-Year 9.714 25-Year 9.714 50-Year 11.839 50-Year 11.839 100-Year 13.592 100-Year 13.592 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals used for pond surface area used for riser diameter project location client by date sheet no. job no. MJB Roadway North Anacortes, WA Merlino Properties Phase 1 Sediment Pond Calculations KNM 1/2021 1900301 Pond Geometry Orifice Diameter Riser Diameter **See Figure 4.2.21 on next page. Q= 100-yr flow*1.6 = 4.0*1.6 = 6.3 cfs 0.6' head over riser required to convey 100-yr design flow capacity of 18' riser with 1' head over riser top is greater than 100-yr design flow ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.52 Program License Number: 200410007 Project Simulation Performed on: 10/28/2020 1:08 PM Report Generation Date: 10/28/2020 1:11 PM ————————————————————————————————— Input File Name: TESC_Runoff into Pond.fld Project Name: MJB Anacortes Analysis Title: Phase 2 Runoff into Sediment Pond Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 60, 15 Extended Precipitation Time Series Selected Climatic Region Number: 12 Full Period of Record Available used for Routing Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 12.646 12.646 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 12.646 12.646 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 12.646 ---------------------------------------------- Subbasin Total 12.646 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 12.646 ---------------------------------------------- Subbasin Total 12.646 *** Point of Compliance Flow Frequency Data for 1 Hour Time Step *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 0.289 2-Year 0.289 5-Year 0.577 5-Year 0.577 10-Year 0.846 10-Year 0.846 25-Year 1.156 25-Year 1.156 50-Year 1.285 50-Year 1.285 100-Year 1.370 100-Year 1.370 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals *** Point of Compliance Flow Frequency Data for 15 Minute Time Step *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 0.353 2-Year 0.353 5-Year 0.669 5-Year 0.669 10-Year 1.033 10-Year 1.033 25-Year 2.078 25-Year 2.078 50-Year 2.657 50-Year 2.657 100-Year 3.272 100-Year 3.272 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals used for pond surface area and pump sizing for primary riser discharge used for riser diameter MJB Roadway North Anacortes, WA Merlino Properties Phase 2 Sediment Pond Calculations KNM 1//2021 1900301 Pond Geometry Orifice Diameter Riser Diameter **See Figure 4.2.21 on next page. project location client by date sheet no. job no. Q= 100-yr flow*1.6 = 1.37*1.6 = 2.19 cfs 0.3' head over riser required to convey 100-yr design flow capacity of 18' riser with 1' head over riser top is greater than 100-yr design flow MJB North Preliminary Plat City of Anacortes, WA Stormwater Site Plan July 2023 | Preliminary Report KPFF Consulting Engineers ii MJB North Roadway –MJB Properties iii Table of Contents Tab 1 – (Minimum Requirement #1 – Prepare a Stormwater Site Plan) ............................................................... 7 Tab 2 – (Minimum Requirement #2 – Construction SWPPP) ............................................................................. 11 Tab 3 – (Minimum Requirement #3 – Source Control of Pollution) .................................................................... 21 Tab 4 – (Minimum Requirement #4 – Preservation of Natural Drainage System) .............................................. 22 Tab 5 – (Minimum Requirement #5 - OSM) ........................................................................................................ 23 Tab 6 – (Minimum Requirement #6 – Runoff Treatment) ................................................................................... 28 Tab 7 – (Minimum Requirement #7 – Flow Control) ........................................................................................... 29 Tab 8 – (Minimum Requirement #8 – Wetland Protection) ................................................................................. 30 Tab 9 – (Minimum Requirement #9 – Operation and Maintenance) ................................................................... 31 Tables Summary Table .................................................................................................................................................... 2 Table 4.1.1: Source Control BMP’s by SWPPP Element ................................................................................... 12 Table 4.2.1: Runoff Conveyance and Treatment BMPs by SWPPP Element ................................................... 13 Figures Figure I-2.4.1: Flow Chart for Determining Requirements for New Development ............................................... 4 Figure I-2.4.2: Flow Chart for Determining Requirements for Redevelopment .................................................... 5 Figure I-2.5.1: Flow Chart for Determining LID MR #5 Requirements ................................................................. 6 Figure 1-1: Drainage Basin Map .......................................................................................................................... 8 Appendices Appendix 1 – Survey Appendix 2 – Geotechnical Reports Appendix 3 – Model Soil Management Plan for BMP T5.13 Appendix 4 – Runoff Treatment Calculations Appendix 5 – Conveyance Calculations KPFF Consulting Engineers iv This page intentionally left blank. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 1 Storm Water Drainage Report Minimum Requirement 1 through 9 ENGINEERING DEPARTMENT 904 6th Street Anacortes, WA 98221 www.anacorteswa.gov Official Use Only: (Information to Inspectors) Required Storm Water Facility and other related requirements: ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ Project Address: 1701 Q Avenue, Anacortes, WA Submittal Date: __________________ Parcel Number: Parcels A-N: P78000, P32963, P32965, P32966, P32967, P32968, P32969, P32970, P32971, P32941, P32916, P32915, P32929, P32913, P58064, P32943 Revision Number: 1 Permit Number: ________________ Reviewer: Steve Lange Acceptance Date (COA):____________ 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: 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 Page 2 Project Description and Summary: Summary Table Existing Proposed Development Type Marine Mixed Use Marine Mixed Use – Preliminary Plat Number of Lots 3 Lots (36, 38, 41) 16 parcels 3 Lots (36, 38, 41) 21 parcels Lot Acreage in SF Total Site Acreage = 28.9 acres (~1,262,037 sf) Total Site Acreage = 28.9 acres (~1,262,037 sf) Soil Type(s) Crushed rock top course, construction rubble and debris, and moderately organic silt/clay Imported structural fill Site Sediment Transport Score (High\Low) Low High (See Appendix 4) Depth to Ground Water Table (Feet and Inches) (See completed Soils Analysis (Volume 1, Chapter 3.1.1) 2.75-3.25 feet N/A Infiltration Rate during Rainy Season (Inch\Per Hour) Not suitable N/A Impervious Surface (on-site) 129,866 sf (2.98 acres) ~1,011,266 sf (23.2 acres) Impervious Surface (off-site) 0 0 New and Replaced Hard Surface Total (SF) N/A ~ 1,011,266 sf (23.2 acres) Lot Coverage (Percentage) 0% 90% BMP (Required Minimum Requirement 5) BMP T5.13 Post- Construction Soil Quality and Depth BMP T5.13 Post- Construction Soil Quality and Depth Water Quality Method (Minimum Requirement 6) None Basic Treatment Water Quantity Method (Minimum Requirement 7) None Not Required 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 Phasing\Sequence ) The existing site conditions are being established during Phases 1 and 2 of the MJB North Roadway Clearing and Grading Permit. Phase 1 is constructing utility infrastructure and roadway alignments including landscape strips and sidewalk for Barcott Way, 17th Street, and 20th Street. These areas were designed to meet stormwater requirements in the 2021 Clearing and Grading Permit. Refer to the 2021 storm report for discussion of those requirements. They are not included in the discussion of this report. The parcel areas included in the preliminary plat are currently vegetated and graded to generally slope toward the north and the shoreline. There are interceptor swales along the western side of Barcott Way and along the north and south sides of 17th Street to intercept stormwater from the western portion of the site and City of Anacortes (City) right-of-way (ROW) that drains towards the roadway. This runoff will be collected by drainage structures in Barcott Way. Future developments on each lot will create their own stormwater collection and conveyance systems while also maintaining the performance of these stormwater BMPs beyond that particular lot line. There are four existing stormwater outfalls to Fidalgo Bay. The storm main in Barcott Way discharges through the northernmost 36-inch outfall. The site is partially within the FEMA 100-year floodplain. The last known permit for the project site was the 2021 grading permit. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 3 Developed Conditions Summary: (Additionally, to be shown on the site plan. Identify cut and fill areas, proposed slopes of all hard surfaces , proposed contours) Future phases of development are expected within the project site. The date and type of development is unknown at this time but could include commercial and multifamily uses consistent with the Marine Mixed-Use zoning. For purposes of determining the future development can meet the minimum stormwater requirements, each parcel is assumed to be 90% impervious, the maximum allowed per Anacortes Municipal Code 19.42.030. The remaining 10% will be pervious green space. Stormwater runoff will be collected and discharged to one of the existing outfalls to Fidalgo Bay. Each parcel will either connect directly to one of the existing outfalls, connect to a storm line within the proposed Shoreline Trail, or connect to the storm main in Barcott Way. Drainage Basin (2007 Storm Comp Plan – City website\publicworks\engineering\comprehensive plans): What Drainage Basin are you in? Fidalgo Drainage Basin Identify any downstream drainage issues (Storm Comp Plan: NA_____ If so, describe: NA Complete the Applicability Requirements – Flow Chart (Figure I-2.4.1 Attached, Figure I-2.4.2 Attached and Figure I-2.5.1 Attached) - Highlight the path and attach Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 4 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 5 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 6 Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 7 TAB 1 – (MINIMUM REQUIREMENT #1 – PREPARE A STORMWATER SITE PLAN) · 1-2.5.1 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. Record of Survey performed – Appendix 1___________________________________________ Preliminary Infiltration Report by Coastal Geologic Services (November 27, 2019) – Appendix 2 Geotechnical Report – 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. Preliminary design plans have not been drawn for the parcels in the preliminary plat. The intent of this report is to demonstrate any future development is capable of meeting stormwater requirements. Refer to the Preliminary Plat plans prepared by PSE for the proposed lot boundaries. Refer to the 2021 Clearing and Grading Permit plans for the location of roads and stormwater facilities in the ROW. 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 ¾ acres of vegetation to lawn or landscape areas, or convert 2.5 acres of forested area to pasture. Off-site analysis extends to ¼ mile downstream of the project site. Task 1: Define and map the study area The study area consists of the Phase 1 roadway location, on-site area that sheet flows into Fidalgo Bay, and off-site area that sheet flows on to the site. See Figure 1 below. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 8 Figure 1 Study Area Task 2: Review all available information on the study area Available information for this study area was reviewed, including GIS maps, FEMA maps, USDA Web Soil Survey map, 303(d) list, and the project survey. Potential flow control issues were not found. Task 3: Field inspect the study area The study area was observed during a site visit on December 10, 2019. The weather was cold, cloudy, with light showers. Task 4: Describe the drainage system, and its existing and predicted problems. The existing drainage system consists of 4 outfalls to Fidalgo Bay. Catch basins within the roadways built since 2020, water quality StormFilters, and pipe that collect and convey stormwater through Barcott Way to the north outfalll. The existing drainage system also consists of pipe and drainage structures that convey stormwater collected in the ROW both east and west of Q Avenue through the project site to an outfall. No evidence of current drainage problems were observed. The contractor will need to protect existing storm pipe that will remain in order to prevent future drainage problems. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 9 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 2.4.2 (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 project falls under Minimum Requirements #1-9 for new and replaced hard surfaces and converted vegetated areas. 1-3.1.5 Step 5 - Prepare a Permanent Stormwater Control Plan (Refer to this section of the Ecology Manual for requirements.) Additional Stormwater Site Plans will be prepared as each lot develops, demonstrating compliance with Minimum Requirements #1 through #9. 1-3.1.6 Step 6 - Prepare a Construction Stormwater Pollution Prevention Plan (MR#2 – 13 Elements) Refer to Chapter II-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 A SWPPP will be prepared when each lot develops. 1-3.1.7 Step 7 - Complete the stormwater site plan <https://docs.cityofanacortes.org/WebLink/Search.aspx> 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 (Tab 1) · Existing Conditions Summary (Tab 1) · Off-site Analysis Report (Tab 1) · Permanent Stormwater Control Plan (Appendix 5) · Construction Stormwater Pollution Prevention Plan (Tab 2) · Special Reports and Studies (Tab 1) · Preliminary Infiltration Report · Geotechnical Report · Critical Areas Report (TBD) · Other Permits (Tab 1) · Clearing and Grading Permit · Preliminary Land Division (TBD) Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 10 · Notice of Intent – Construction Stormwater General Permit (Washington State Department of Ecology) · Operation and Maintenance Manual (Appendix 9) · Declaration of Covenant for Privately Maintained Flow Control and Treatment Facilities. (See attached Drainage BMP Maintenance Covenant BMP Agreement) · Declaration of Covenant for Privately Maintained On-site Stormwater BMP’s (See attached Drainage BMP Maintenance Covenant BMP Agreement) (Appendix 7) · Bond Quantities Worksheet, if applicable __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ ______________________________________________________________ 1-3.1.8 Step 8 - Check Compliance with all Applicable Minimum Requirements A Stormwater Site Plan as designed and implemented should specifically fulfill all Minimum Requirements applicable to the project. The Stormwater Site Plan should be reviewed to check that these requirements are satisfied. Project has the ability to fulfill all Minimum Requirements applicable to the project. __________________________________________________________________________________ ________________________________________________________________________ Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 11 TAB 2 – (MINIMUM REQUIREMENT #2 – CONSTRUCTION SWPPP) · 1-2.5.2 Minimum Requirement #2 – Construction Stormwater Pollution Prevention Plan (SWPPP) - All projects are required to complete Minimum Requirement 2. - Refer to the 13 Elements of the SWPPP (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. Temporary Erosion and Sediment Control (TESC) BMPs will be implemented during construction to prevent, to the maximum extent feasible, the transport of sediment from the project site. TESC BMPs are anticipated to include stabilized construction entrances, silt fencing, interceptor swales, check dams, storm drain inlet protection, culverts, mulching of exposed areas, dust control, a sediment pond, and other measures as necessary. A SWPPP will be prepared when each lot develops. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 12 Table 4.1.1 Source Control BMP’s by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 13 Table 4.2.1 Runoff Conveyance and Treatment BMPs by SWPPP Element Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 14 13 Elements of SWPPP (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 (SWMMWW). 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: MJB Properties, Inc. Site Address: Q Avenue, Anacortes, WA Prepared By: KPFF Consulting Engineers 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. BMP C103 High Visibility Fence may be provided to contain the site. __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 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. X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 15 Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. Construction entrances will be installed. BMP C105 Stabilized Construction Entrance ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ELEMENT 3: Control Flow 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. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 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. BMP C233 Silt Fence BMP C105 Stabilized Construction Entrance BMP C220 Storm Drain Inlet Protection ________________________________________________________________________________________ ________________________________________________________________________________________ X X X X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 16 ________________________________________________________________________________________ ______________________________________________________________________________________ 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 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. BMP C121 Mulching BMP C123 Plastic Covering BMP C140 Dust Control ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 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 slope 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. X X X X X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 17 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. Site is relatively flat and does not have any steep slopes. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 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 waters of the State. Inlets should be inspected weekly at a minimum and daily during storm events. BMP C220 Storm Drain Inlet Protection ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 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. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ X X X X X X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 18 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. 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. All paints and solvents will be stored under cover out of the weather elements Contractor to have a spill prevention kit at all times 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. X X X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 19 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. Infiltration 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. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 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 documents. Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. Contractor will be responsible for maintaining all BMPs BMPs will be inspected daily, as necessary per the 2014 DOE SWMMWW Appendix II-A. Weekly erosion and sedimentation reports are to be sent to the City ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 20 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. Contractor will manage the site. ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ 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 infiltrating or dispersion LID BMPs are proposed at this time ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ________________________________________________________________________________________ ___________________________________________ _____________________ Applicant Signature Date X X X X X X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 21 TAB 3 – (MINIMUM REQUIREMENT #3 – SOURCE CONTROL OF POLLUTION) · 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) Operational Source Control BMP’s Water quality source controls applicable to this project will be applied in accordance with the 2014 Stormwater Management Manual for Western Washington. They will be discussed in the future SWPPP. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 22 TAB 4 – (MINIMUM REQUIREMENT #4 – PRESERVATION OF NATURAL DRAINAGE SYSTEM) · Minimum Requirement #4 – Preservation of Natural Drainage Systems and Outfalls 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? Yes\No. If yes, refer to section I.2.5.4 for Supplemental Guidelines for additional information. Stormwater currently discharges to Fidalgo Bay through sheet flow and piped outfalls. This project will maintain both means of discharge to Fidalgo Bay. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 23 TAB 5 – (MINIMUM REQUIREMENT #5 - OSM) · 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 BMP’s 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? Yes (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). The site is flow control exempt because stormwater runoff is discharged to the direct discharge exempt waterbody of Fidalgo Bay per 2014 DOE SWDM Section I-2.5.7. __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ If the project is Flow Control Exempt, select from the list below (Skip List 1 and List 2). o BMP T5.13 Post Construction Soils Quality and Depth o BMP T5.10A: Downspout Full Infiltration, or; o BMP T5.10B Downspout Dispersion Systems, or; o BMP T5.10C: Performated Stub-out Connections, or; o BMP T5.11 Concentrated Flow Dispersion, or; o BMP T5.12 Sheet Flow Dispersion Projects triggering Minimum Requirements 1 through 9, must meet the requirements in 1-2.5.5 Minimum Requirement 5 – On-site Stormwater Management. o Refer to Table I-2.5.1 On-site Stormwater Management Requirements for Projects Triggering Minimum Requirements 1 through 9 in the Department of Ecology Manual. The site is not required to meet the Low Impact Development Performance Standards per the Flow Control direct discharge exemption. The minimum requirement consists of providing BMP T5.13 for Post Construction Soil Quality and Depth. X Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 24 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. 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. Appendix 3 is a deferred submittal. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 25 List #2 – Project Triggering Minimum Requirement 1 through 9 For each surface, consider the BMPs 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. Provide feasible detail under each BMP with maintenance and operations specifications in Minimum Requirement 5. Roofs: List #2 1. BMP T5.30: Full Dispersion Feasible\Infeasible If infeasible, explain the criteria: The site will not have an adequate length of native vegetated flow path to disperse to. Or, T5.10A: Downspout Full Infiltration Feasible\Infeasible If infeasible, explain the criteria: Stormwater management using full infiltration in accordance with BMP T5.10A, rain gardens per BMP T5.14A and infiltrating bioretention facilities in accordance with Chapter 7 Volume V are infeasible due to the fill soils on-site. 2. BMP T7.30: Bioretention Cells, Swales and Planter Boxes Feasible\Infeasible If infeasible, explain the criteria: Stormwater management using full infiltration in accordance with BMP T5.10A, rain gardens per BMP T5.14A and infiltrating bioretention facilities in accordance with Chapter 7 Volume V are infeasible due to the fill soils on-site. Non-infiltrating bioretention planters are a potential option for Water Quality treatment. 3. BMP T5.10B: Downspout Dispersion Systems Feasible\Infeasible If infeasible, explain the criteria: There will not be an adequate vegetated flow path length. 4. BMP T5.10C: Perforated Stub-out Connections Feasible\Infeasible If infeasible, explain the criteria: The fill soils on-site are not appropriate for infiltration. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 26 Other Hard Surfaces: List #2 1. BMP T.5.30 Full Dispersion Feasible\Infeasible If infeasible, explain the criteria: Not feasible per Preliminary Infiltration Report. 2. BMP T5.15: Permeable Pavements Feasible\Infeasible If infeasible, explain the criteria: Not feasible per Preliminary Infiltration Report. 3. BMP T7.30: Bioretention Cells, Swales and Planter Boxes Feasible\Infeasible If infeasible, explain the criteria: The existing soils are not suitable for reuse as filtration media in stormwater treatment BMPs per the Preliminary Infiltration Report. 4. BMP T5.12: Sheet Flow Dispersion Feasible\Infeasible If infeasible, explain the criteria: Not feasible per Preliminary Infiltration Report. Or, BMP T5.11: Concentrated Flow Dispersion Feasible\Infeasible If infeasible, explain the criteria: Not feasible per Preliminary Infiltration Report. ___________________________________________ _____________________ Applicant Signature Date Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 27 Existing Conveyance System There are four existing outfalls to Fidalgo Bay on-site, described below. There is a 36-inch concrete storm pipe in the northeast corner of the project with a connection to the storm main in Barcott Way. The 18-inch concrete storm pipe approximately 260 feet south of the 36-inch pipe was capped east of Barcott Way in Phase 1. The 8-inch ductile iron pipe approximately 350 feet south of the 18-inch pipe was capped east of Barcott Way in Phase 1. The 12-inch corrugated metal pipe (CMP) was capped east of Barcott Way in Phase 1. The Phase 1 roadway stormwater runoff is collected via catch basins with Contech Stormfilter cartridges before being conveyed to the 36-inch stormwater outfall in a 12 to 30-inch mainline pipe. The mainline pipe slopes range from 0.35% to 1.1%. The existing pipe network was designed to have capacity for the 100-year storm event from the entire area bounded by Q/R Avenue to the west, 22nd Street to the south, Barcott Way to the east, and the property line to the north. Also included in the calculations was stormwater runoff from an area of existing development west of the site that is intercepted by the Phase 1 storm system. Roadways and off-site runon were counted as fully impervious. Undeveloped parcels between the roads were counted as 90% impervious because future development will be required to meet impervious coverage requirements in the Anacortes Municipal Code. Runoff flow rates were determined using MGSFlood modeling software. Calculations for pipe conveyance capacity were performed using manning’s equation. The 30-inch pipe at the downstream end of Barcott Way has a capacity of 22.5 CFS (cubic feet per second). The area’s fully impervious 100-year runoff flow rate is 19.0 CFS. See the spreadsheet and coordinating drainage basin exhibit for complete calculations and page 33 of the June 2021 Stormwater Site Report in Appendix 5 for further discussion. Proposed Conveyance System Future development east of Barcott Way will connect to the existing storm drain outfalls to Fidalgo Bay, with the option to evaluate connecting some parcels to the Barcott Way storm main. Parcels also have the option to run new storm lines under the shoreline tract to connect to an existing outfall with capacity. Calculations were performed to show that the existing outfalls have adequate capacity for 90% impervious build out of the parcels between Barcott Way and Fidalgo Bay. This area’s 100-year runoff flow rate is 8.8 CFS. Individual parcels can connect to their nearest existing outfall until the outfall’s capacity is reached, connect to the Barcott Way storm main until capacity is reached, or connect to a storm line under the shoreline tract which discharges to an existing outfall with capacity. The existing 12-inch outfall has a capacity of 1.9 CFS; the 8-inch outfall has 0.7 CFS; the 18-inch has 10.5 CFS; the 36-inch has 66.7 CFS. Together, all four existing outfalls have a combined capacity of 79.8 CFS, which is greater than the entire drainage basin’s flow (27.7 CFS); therefore, the drainage system has sufficient capacity for future build out conditions. See Appendix 5 for Overall Drainage Basin Exhibit, MGSFlood report, and pipe capacity output for calculations. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 28 TAB 6 – (MINIMUM REQUIREMENT #6 – RUNOFF TREATMENT) Refer to 1.2.5.6 and provide the required information for this Minimum Requirement. Per Volume I, Section I-2.5.6 of the 2014 Stormwater Management Manual for Western Washington, the project will create greater than 5,000 square feet of pollution generating impervious surface (PGIS), and thus will be required to provide water quality runoff treatment. The site is subject to Basic Treatment per Volume I Appendix I-C, for Basic Treatment Receiving Waters. Enhanced Basic Treatment and Phosporous Control are not required. Oil Control is not required because the site is not a “high-use” roadway. For purposes of demonstrating compliance with Water Quality Treatment requirements, the worst case scenario was assumed for calculations—the entire maximum allowed impervious surface of the largest parcel was assumed to be PGIS. The largest parcel is 80,669 SF, so treatment was sized for 72,602 SF of PGIS. The future development can explore multiple options for treatment including, but not limited to, non-infiltrating bioretention and proprietary treatment systems such as the StormFilter. Contech Engineered Solutions’ StormFilter with ZPG Media has achieved General Use Level Designation (GULD) and is therefore an appropriate emerging technology to provide Basic Treatment. Included in Appendix 4 is the Washington State Department of Ecology’s GULD decision for this product. The water quality design flow rate is the peak 15-minute flow rate as calculated by MGS Flood by MGS Engineering Consultants, Inc, which is an approved continuous runoff model. The largest parcel has a 15- minute peak flow rate of 0.235 cfs. This would require six 18-inch StormFilter cartridges in a 6-foot by 8-foot vault or 72-inch manhole which could fit within the parcel; therefore, water quality treatment could be provided via StormFilters. The water quality design 91% exceedance volume as calculated by MGSFlood is 5,178 cubic feet. This equates to a non-infiltrating bioretention planter with 12” ponding depth and 5,178 square foot bottom area. The available site area outside of the impervious area is 8,067 square feet; therefore, water quality treatment could be provided via non-infiltrating bioretention. See Appendix 4 for Runoff Treatment calculations. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 29 TAB 7 – (MINIMUM REQUIREMENT #7 – FLOW CONTROL) Refer to 1.2.5.7 and provide the required information for this Minimum Requirement. The project is not required to meet flow control requirements because it discharges to Fidalgo Bay, which is a flow-control exempt water body per Volume I, Appendix I-E of the 2014 Stormwater Management Manual for Western Washington. See Appendix 5 of this report for conveyance capacity calculations for the proposed storm system and existing storm systems that are being reused. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 30 TAB 8 – (MINIMUM REQUIREMENT #8 – WETLAND PROTECTION) Refer to 1.2.5.8 and provide the required information for this Minimum Requirement. No critical areas report has been performed for the site at this time. Additional requirements may be needed. Version Date: October 7, 2019 Previous Version Date: February 20, 2019 Page 31 TAB 9 – (MINIMUM REQUIREMENT #9 – OPERATION AND MAINTENANCE) Refer to 1.2.5.9 and provide the required information for this Minimum Requirement. Operation and Maintenance requirements will be provided at the time of full site design. MJB North Roadway –MJB Properties Appendix 1 Appendix 1 Survey PACIFIC SURVEYING & ENGINEERING, INC. 909 Squalicum Way, Suite 111 | BELLINGHAM, WA 98225 T: 360.671.7387 | F: 360.671.4685 WWW.PSESURVEY.COM | INFO@PSESURVEY.COM PRELIMINARY PLAT SEATTLE,WA 98134 5050 1ST AVENUE S., SUITE 102 OWNERS: MJB PROPERTIES, LLC SHEET OF 31 PR E L I M I N A R Y 19 FIDALGO LANDING PLAT SECTION 19, TOWNSHIP 35 NORTH, RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE NORTH HALF OF THE SOUTHWEST QUARTER AND THE SOUTH HALF OF THE NORTHWEST QUARTER OF VICINITY MAP (NTS) PACIFIC SURVEYING & ENGINEERING, INC. 909 Squalicum Way, Suite 111 | BELLINGHAM, WA 98225 T: 360.671.7387 | F: 360.671.4685 WWW.PSESURVEY.COM | INFO@PSESURVEY.COM PRELIMINARY PLAT SEATTLE,WA 98134 5050 1ST AVENUE S., SUITE 102 MJB PROPERTIES, LLC SHEET OF 32 PR E L I M I N A R Y FIDALGO LANDING PLAT SECTION 19, TOWNSHIP 35 NORTH, RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE NORTH HALF OF THE SOUTHWEST QUARTER AND THE SOUTH HALF OF THE NORTHWEST QUARTER OF 30'30' 30 ' 30 ' 30'30' 30'30' 30'30' 3 0 ' 3 0 ' 95' 95' ANACORTES HARBOR PLATE 10 ANACORTES INDUSTRIAL PARK ADDITION AF#768819 BLOCK 8 BLOCK 1 ANACORTES HARBOR PLATE 10 ANACORTES HARBOR PLATE 10 FIDALGO BAY ANACORTES HARBOR PLATE 10 ANACORTES HARBOR PLATE 10 ANACORTES HARBOR PLATE 10 LOT 3 18TH STREET 17TH STREET 19TH STREET 32' 40' 40' 32' LOT 1 'R ' A V E . LOT 2 BLOCK 4 BLOCK 5 'Q ' A V E N U E 20TH STREET F O R M E R G N R R ' Q ' A V E N U E 22ND STREET 21ST STREET 'R ' A V E N U E LOT 35 ' T ' A V E . 40 ' 40 ' 32'40' 'R ' A V E N U E 80' NELSON'S ADD. TO ANACORTES V.2, P.102 ∆ ∆ ∆∆ ∆ TOTAL PLAT ACREAGE 54.3 ACRES +/- (29.8 +/- UPLAND)30 ' 30 ' 3 0 ' FIDALGO LANDING PLAT SECTION 19, TOWNSHIP 35 NORTH, RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE NORTH HALF OF THE SOUTHWEST QUARTER AND THE SOUTH HALF OF THE NORTHWEST QUARTER OF 200 100 50 0 100 1 i n c h = 100 f e e t G R A P H I C S C A L E ( U S S U R V E Y F E E T ) PACIFIC SURVEYING & ENGINEERING, INC. 909 Squalicum Way, Suite 111 | BELLINGHAM, WA 98225 T: 360.671.7387 | F: 360.671.4685 WWW.PSESURVEY.COM | INFO@PSESURVEY.COM PRELIMINARY PLAT SEATTLE,WA 98134 5050 1ST AVENUE S., SUITE 102 MJB PROPERTIES, LLC SHEET OF 33 PR E L I M I N A R Y LOT 2B LOT 2A LOT 1 OCCUPATIONAL INDICATORS NOTE RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 1 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS TOPOGRAPHIC SURVEY & EXISTING CONDITIONS VACATED 17TH STREET(ORDINANCE NO. 1834) VA C A T E D ' R ' A V E N U E (O R D I N A N C E N O . 7 8 3 ) PARCEL 'M' PARCEL 'M' PARCEL 'N' 17TH STREET 'Q ' A V E PARCEL 'N' PARCEL 'K' RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 2 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SE E S H E E T 3 SEE SHEET 4 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS TOPOGRAPHIC SURVEY & EXISTING CONDITIONS FIDALGO BAY PARCEL 'B' PARCEL 'C' PARCEL 'C' PARCEL 'M' PARCEL 'M' PARCEL 'N' 'R ' A V E RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, TOPOGRAPHIC SURVEY & EXISTING CONDITIONS PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 3 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 5 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SE E S H E E T 2 VA C A T E D ' R ' A V E N U E (O R D I N A N C E N O . 1 8 3 4 ) PARCEL 'M' PARCEL 'K' PARCEL 'L' ' Q ' A V E VA C A T E D ' R ' A V E N U E (O R D I N A N C E N O . 1 8 3 4 ) PARCEL 'K' RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 4 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 6 SE E S H E E T 5 SEE SHEET 2 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE TOPOGRAPHIC SURVEY & EXISTING CONDITIONS FIDALGO BAY PARCEL 'C' PARCEL 'L' PARCEL 'E' PARCEL 'J' PARCEL 'D' PARCEL 'E' RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 5 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 7 SEE SHEET 3 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SE E S H E E T 4 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS PARCEL 'K' PARCEL 'J' 2OTH STREET VA C A T E D ' R ' A V E N U E (O R D I N A N C E N O . 1 8 3 4 ) RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 6 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 4 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SEE SHEET 8 SE E S H E E T 7 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS FIDALGO BAY VACATED 20TH STREET(ORDINANCE NO. 1476) PARCEL 'J' PARCEL 'F' PARCEL 'F' PARCEL 'H' PARCEL 'E'RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 7 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 9 SEE SHEET 5 SE E S H E E T 6 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS 'R ' A V E VACATED 20TH STREET(ORDINANCE NO. 1476) VACATED 21ST STREET(ORDINANCE NO. 1476) VACATED ALLEY(ORDINANCE NO. 1476) PARCEL 'A' PARCEL 'A' 21ST STREET 2OTH STREET ' Q ' A V E RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 8 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 10 SE E S H E E T 9 SEE SHEET 6 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE TOPOGRAPHIC SURVEY & EXISTING CONDITIONS VACATED 20TH STREET(ORDINANCE NO. 1476) VACATED 21ST STREET(ORDINANCE NO. 1476) VA C A T E D ' S ' A V E N U E (O R D I N A N C E N O . 1 4 8 7 ) VA C A T E D ' S ' A V E N U E (O R D I N A N C E N O . 1 4 8 7 ) PARCEL 'G' PARCEL 'H' PARCEL 'A' PARCEL 'A' PARCEL 'A' FIDALGO BAY VACATED 21ST STREET(ORDINANCE NO. 1476) PARCEL 'A' RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 9 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SE E S H E E T 8 SEE SHEET 7 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SEE SHEET 11 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS 'R' A V E 22ND STREET 'R' A V E 'R' AVE 'R ' A V E 22ND STREET ' R ' A V E ' R ' A V E VACATED ALLEY(ORDINANCE NO. 1476) RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 10 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SE E S H E E T 1 1 SEE SHEET 8 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE TOPOGRAPHIC SURVEY & EXISTING CONDITIONS FIDALGO BAY VACATED ALLEY(ORDINANCE NO. 1487) ' T ' A V E N U E VA C A T E D ' S ' A V E N U E (O R D I N A N C E N O . 1 4 8 7 ) PARCEL 'A'RANGE 2 EAST, W.M., CITY OF ANACORTES, SKAGIT COUNTY, WASHINGTON SITUATE IN A PORTION OF THE SOUTHEAST QUARTER OF SECTION 19, TOWNSHIP 35 NORTH, PA C I F I C S U R V E Y & E N G I N E E R I N G I N C TOPOGRAPHIC SURVEY & EXISTING CONDITIONS SOUTH CAP SANTE MARINA VICINITY ANACORTES, WASHINGTON ww w . p s e s u r v e y . c o m EM A I L : i n f o @ p s e s u r v e y . c o m CALL BEFORE YOU DIG 1-800-424-5555 SHEET 11 OF 11JOB #: 2019102 MJB PROPERTIES, LLC 5050 1ST AVENUE S., SUITE 102 SEATTLE,WA 98134 90 9 S Q U A L I C U M W A Y · S U I T E 1 1 1 · BE L L I N G H A M , W A 9 8 2 2 5 P H O N E : 3 6 0 . 6 7 1 . 7 3 8 7 F A X : 3 6 0 . 6 7 1 . 4 6 8 5 SEE SHEET 9 40 200(us survey feet) 1020 1inch = 20 feet GRAPHIC SCALE SE E S H E E T 1 0 TOPOGRAPHIC SURVEY & EXISTING CONDITIONS MJB North Roadway –MJB Properties Appendix 2 Appendix 2 Geotechnical Reports The Preliminary Infiltration Report by Coastal Geologic Services on November 27, 2019 and the Geotechnical Report prepared by PanGeo on Feburary 12, 2021 are attached in this Appendix. Geotechnical & Earthquake Engineering Consultants GEOTECHNICAL REPORT MJB North Shoreline Anacortes, Washington PROJECT NO. 21-038 February 2021 Prepared for: Merlino Properties ________________________________________________ 3213 Eastlake Avenue East, Ste B Seattle, WA 98102 Tel (206) 262-0370 Fax (206) 262-0374 Geotechnical & Earthquake Engineering Consultants February 12, 2021 Project No. 21-038 Jimmy Blais Merlino Properties 5050 First Avenue South, Suite 102 Seattle, WA 98134 Subject: Geotechnical Report Site Grading and Earthwork MJB North Shoreline, Anacortes, Washington Dear Mr. Blais, This report outlined the results and recommendations of our geotechnical study to support the design and construction of the proposed roadways and general earthwork for the site. The findings outlined in the current report is based on the results of our cone penetration tests (CPTs) completed at the site. We will update our report after completion of supplemental test borings and laboratory testing. The test borings and laboratory test results will be used to refine our settlement estimate but other findings are anticipated to remain as discussed in this report. Based on the results of our CPTs, the site is underlain by a sequence of existing granular fill, soft to medium stiff silt/clay with sand mixtures to 15 to 40 feet deep, in turn underlain by medium dense to dense sand and silty sand. The proposed roadway embankments as currently designed are appropriate. The underlying soils are also subject to liquefaction induced settlements during a strong seismic event consistent with the 2018 IBC. We appreciate the opportunity to assist you with this project. We are available to meet to discuss our findings at your convenience. Sincerely, Siew L. Tan, P.E. Principal Geotechnical Engineer i TABLE OF CONTENTS 1.0 GENERAL ............................................................................................................................... 1 2.0 SITE AND PROJECT DESCRIPTION ............................................................................... 1 3.0 SUBSURFACE EXPLORATIONS ....................................................................................... 3 4.0 SUBSURFACE CONDITIONS ............................................................................................. 3 4.1 GEOLOGY ............................................................................................................................... 3 4.2 SOIL ....................................................................................................................................... 4 4.3 GROUNDWATER ..................................................................................................................... 4 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................ 5 5.1 SEISMIC SITE CLASS ............................................................................................................... 5 5.2 SOIL LIQUEFACTION ............................................................................................................... 5 5.3 CONCEPTUAL BUILDING FOUNDATION APPROACH ................................................................ 6 5.4 SITE STRIPPING AND CLEARING ............................................................................................. 6 5.5 SELECTION OF FILL MATERIALS ............................................................................................. 7 5.6 ROADWAY CONSTRUCTION AND FILL SLOPE STABILITY ........................................................ 8 5.7 SETTLEMENT ESTIMATE AND MONITORING ........................................................................... 9 5.8 UTILITIES ............................................................................................................................. 11 5.8.1 Trench Excavations ...................................................................................................... 11 5.8.2 Dewatering ................................................................................................................... 11 5.8.3 Pipe Bedding ................................................................................................................ 12 5.8.4 Trench Backfill ............................................................................................................. 12 5.9 GENERAL EARTHWORK RECOMMENDATIONS ...................................................................... 13 5.9.1 Fill Compaction ........................................................................................................... 13 5.9.2 Wet Weather Earthwork ............................................................................................... 13 6.0 LIMITATIONS ..................................................................................................................... 14 7.0 REFERENCES ...................................................................................................................... 16 LIST OF ATTACHMENTS: Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Figure 3A Generalized Subsurface Profile A-A’ Figure 3B Generalized Subsurface Profile B-B’ Figure 4 Slope Stability Analysis – Static Condition Figure 5 Slope Stability Analysis – Pseudo Static Condition Figure 6 Slope Stability Analysis – Post-Liquefaction Condition Figure 7 Settlement Plate Detail Appendix A Summary CPT Logs 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 1 GEOTECHNICAL REPORT SITE GRADING AND EARTHWORK MJB North Shoreline, Anacortes, WASHINGTON 1.0 GENERAL This report presents the results of our geotechnical engineering study to support the proposed grading activities at the MJB North Shoreline property in Anacortes, Washington. Our service scope to date included conducting a site reconnaissance, reviewing readily available geologic data, advancing ten cone penetration tests at the site, and developing the conclusions and recommendations presented in this report. 2.0 SITE AND PROJECT DESCRIPTION The project site is in Anacortes, Washington. It borders Q Avenue to the west, Fidalgo Bay to the east, 17th Avenue to the north, and 22nd Avenue to the South. The approximate location of the site is shown in the attached Figure 1. The site has an upland area of about 28 acres. The ground surface descends gently from Q Avenue to the shore of Fidalgo Bay. The topographic relief is about 10 feet between Q Avenue and the shoreline. The site is mostly vacant, with a few storage buildings located along the west side of the site. We understand that the property will be developed in phases and the final development plan is currently being developed. When completed, as currently envisaged, the development may include residential units, hotels, retail, restaurants, an event center, and parking lots. A new north-south trending roadway (T Avenue) will be constructed in the middle of the site, connecting 17th Avenue on the south and 22nd Avenue on the north. The proposed T Avenue will be about 1,600 feet long. The existing 17th Avenue, between Q Avenue and T Avenue, will also be regraded. A preliminary conceptual site layout is shown in Plate 1 on the following page. We understand that fill will be placed to raise the site grade for the proposed development. Along the proposed T Avenue, as much as about 10 feet of fill will be placed above the existing grade. Along 17th Avenue, the new fill will generally be less than about 4 feet above the existing grade. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 2 Plate 1. Preliminary conceptual site plan. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 3 3.0 SUBSURFACE EXPLORATIONS PanGEO completed ten Cone Penetration Tests (CPT-1 to CPT-10) on February 1 and 8, 2021. The CPTs were performed by ConeTec Inc. at the approximate locations indicated on the attached Figure 2. The CPT probes were advanced to depths of about 56 to 97 feet below the existing ground surface when refusal was met. ConeTec used an instrumented cone approximately 1½ inches in diameter, which is pushed into the soil at a steady rate to measure tip resistance (Qt), side friction (Fs), pore water pressure (u), soil behavior type, and correlated SPT blow counts. The readings on the soil are taken at about 2-inch vertical intervals, and provide a nearly continuous readout of soil stratigraphy, strength, and other parameters. Summary CPT logs are included in Appendix A of this report. 4.0 SUBSURFACE CONDITIONS 4.1 GEOLOGY Our interpretation of the geologic conditions at the site vicinity is based on a review of the Geologic Map of the Anacortes South and La Conner 7.5-minute Quadrangles (Dragovich, at al, 2000), and the Geologic map of the Bellingham 1:100,000 Quadrangle (Lapen, 2000). In summary, a portion of downtown Anacortes east of Commercial Avenue, including the project site, was raised to current elevations by placing fill over Nearshore Deposits (Qn). Nearshore deposits are described as interbedded fine sand, silt, and clay with some peat and organic deposits. The composition of fill can be highly variable and are generally relatively loose in nature. West of the areas that were previously filled, the surficial geology is mapped as Glaciomarine Drift (Qgdm) from the Everson interstade of the Fraser glaciation. The Glaciomarine Drift is characterized as soft silt and clay with sand lenses. South of the project site near the shoreline is mapped as Glaciomarine Outwash (Qgom) from the Everson interstade of the Fraser Glaciation. The Glaciomarine Outwash is characterized as sand and sandy gravel with some silt and clay interbeds. The Glaciomarine Drift and Outwash Deposits are likely underlain by older till, which has been overridden by glacial ice and is consequently very dense/hard. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 4 4.2 SOIL The results from our CPTs indicate that the subsurface conditions at the site are relatively consistent. The following summarizes the subsurface conditions encountered in our CPTs: Unit 1: Fill – At each CPT location, we encountered existing surficial fill that ranged from 3 to 8 feet thick. The composition of the fill material varied across the project area, generally consisting of gravel, sand, and silty mixtures. The relative density of the fill varied from loose to very dense. Unit 2: Glaciomarine Drift – Below the surficial fill, we encountered a layer of soft to medium stiff, silt and clay mixtures with sand lenses. Based on the variable and mixed soil behavior type and the relatively soft consistency, we interpret this soil unit as Glaciomarine Drift mapped near the site. The thickness of this soil unit varies across the site, and its bottom ranges from 17 to 40 feet below the existing ground surface. This soil unit is moderately compressible and could experience long term settlement when loads are applied. Unit 3: Glaciomarine Outwash (Qgom) – Below the Glaciomarine Drift we encountered a layer of medium dense to very dense sand and sand mixtures with silt and clay. This soil unit appeared to have occasional thick layers of uniform consistency. Based on the dense and sandy consistency, we interpret this soil unit as the nearby mapped Glaciomarine Outwash Deposits. This soil unit extended to the bottom of each CPT before reaching practical refusal between 56 and 97 feet deep. We also generated two subsurface profiles to depict the subsurface conditions encountered in our CPTs. The subsurface profiles are included in Figures 3A and 3B. 4.3 GROUNDWATER Groundwater table was generally estimated around 5 to 6 feet below the existing grade using dissipation tests and interpolation from the dynamic pore pressure. Plots of the recorded dissipation tests can be seen in Appendix A. It should be noted that groundwater elevations may vary depending on the season, local subsurface conditions, tide elevations, and other factors. Groundwater levels are normally highest during the winter and early spring. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 5 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 SEISMIC SITE CLASS We anticipate the seismic design of the buildings will be based on the 2018 International Building Code (IBC). The IBC seismic design parameters are in part based on the site soil conditions and site classifications defined in Chapter 20 of ASCE 7-16. According to Chapter 20 of ASCE 7-16, the site soil should be classified as Site Class F because of its liquefaction potential during a strong seismic event (see discussions regarding liquefaction in Section 5.2 of this report). Review of Section 20.3.1 of ASCE 7-16 indicates that for Site Class F a site-specific ground response analysis shall be performed unless the exception to Section 20.3.1 is applicable. Section 20.3.1 of ASCE 7 states that “For structures having fundamental periods of vibration equal to or less than 0.5s, site response analysis is not required to determine spectral accelerations for liquefiable soils. Rather, a site class is permitted to be determined in accordance with Section 20.3 and the corresponding values of Fa and Fv determined from Tables 11.4-1 and 11.4-2.” In other words, for structures with a period of vibration equal to or less than 0.5 second and situated on liquefiable soils, the ASCE 7-16 exception allows the values of Fa and Fv for liquefiable soils be taken equal to the values of site class determined without regard to soil liquefaction. Generally, buildings that are less than 5 stories in height typically meet this exception but should be verified by the structural engineer. Based on the results of our subsurface explorations, the average correlated N60 value was greater than 15 in all 10 CPTs. As, such, if the vibration period for a proposed building is less than 0.5 second, Site Class D may be assumed for determining site coefficients without the needs for a site- specific ground response analysis. However, if the fundamental period of vibration for the proposed buildings exceeds 0.5 seconds, Site Class F should be used. PanGEO can perform the site-specific ground response analysis when requested. 5.2 SOIL LIQUEFACTION Liquefaction occurs when saturated predominately sand and silt soils are subjected to cyclic loading. This causes the porewater pressure to increase in the soil, thereby reducing the inter- granular stresses. As the inter-granular stresses are reduced, the shearing resistance of the soil decreases. If pore pressures develop to the point where the effective stresses acting between the grains become zero, the soil particles will be in suspension and behave like a viscous fluid. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 6 Typically, loose, saturated granular soils have the greatest potential for liquefaction, while more dense soil deposits with higher silt or clay contents have a lesser potential. Soil liquefaction may cause the temporary loss/reduction of foundation capacity, lateral movement of sloping ground, and ground settlement. We evaluate the potential for soil liquefaction and calculated the magnitude of liquefaction-induced settlement based on the results of our CPTs. Our analysis uses the methods proposed by Idriss and Boulanger (2014) and Cetin et al. (2009) and was performed based on an earthquake magnitude of 7.5 and a PGA of 0.48g, which are consistent with the 2018 IBC. In summary, our results indicate that liquefaction could extend to depths greater than 70-plus feet. However, liquefaction-induced settlement deeper than 60 feet should not manifest itself to the surface (Cetin et al., 2009). We estimate that surficial settlement due to soil liquefaction should be no more than 4 to 6 inches. This magnitude of settlement would not impact the grading as currently designed. A more detailed analysis will be performed during the final design of the proposed buildings. Based on the relatively level site grade and the 100-foot setback for building development along the shoreline, it is our opinion that the overall risk for lateral spreading is low and should not impact the proposed development. 5.3 CONCEPTUAL BUILDING FOUNDATION APPROACH Selection of building foundation types depend on several factors, including the site soil conditions, building types, design columns loads, and desired level of performance. PanGEO will provide design- level recommendations during the final design phase of the proposed buildings. For general planning purposes, for wood-framed structures less than three floors in height, we anticipate that the use of conventional footings, a mat foundation, or a structural slab with thickened edges are likely adequate. For taller buildings, the use of ground improvement methods maybe necessary to support these taller buildings on shallow foundations. Alternatively, the use of piles may also be considered. 5.4 SITE STRIPPING AND CLEARING Prior to placement of new fill to raise the site grade, general site clearing should include removal of existing structures, debris, refuse, and other deleterious material. Existing topsoil, where not combined with refuse or other deleterious material, may be stripped and stockpiled for use in landscape areas following final grading of site improvements. In no case should the stripped or Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 7 grubbed materials be used as structural fill or mixed with material to be used as structural fill. The stripped materials may be “wasted” on site in non-structural landscaping areas or they should be exported from the site. Existing utility pipes to be abandoned should be filled or removed so they do not provide a conduit for water flow and potential loss of soils adjacent to the pipes. 5.5 SELECTION OF FILL MATERIALS Import materials to raise the site grade and to construct the roadway should generally consist of Gravel Borrow (Section 9-03.14(1), WSDOT Standard Specifications, 2020), or Select Borrow (Section 9-03.14(2), WSDOT Standard Specifications, 2020). The gradational requirements for Gravel Borrow and Select Borrow are summarized in Table 1, below: Table 1 – Gradational Requirements based on Percent Passing by Weight Sieve Size Gravel Borrow1 Select Borrow2 6-inch - 99 - 100 4-inch 99 - 100 - 3-inch - 75 - 100 2-inch 75 -80 - #4 30 max. - #40 - 50 max. #200 7.0 max 10.0 max Sand Equivalent 50 min. 30 min. 1. Gravel Borrow gradation requirements per Section 9-03.14(1) of WSDOT Standard Specification, 2020. 2. Select Borrow gradation requirements per Section 9-03.14(1) of WSDOT Standard Specification, 2020. The fill should be compacted to at least 95 percent of its maximum dry density, determined in accordance with Modified Proctor Tests (ASTM D1557). The use of recycled materials such as recycled crushed concrete and recycled asphalt may also be considered, provided that these materials will be allowed by the permitting agencies. Recycled crushed asphalt, if used, it should be blended with soil aggregate and the blended products should contain no more than 20% of recycled asphalt. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 8 5.6 ROADWAY CONSTRUCTION AND FILL SLOPE STABILITY Based on our review of the grading plans prepared by KPFF, dated 8/8/2020, as much as 10 feet of fill will be placed to raise the grade along the centerline of the proposed T Avenue (A-Line), and the embankment slopes will be graded to 4H:1V (horizontal:vertical). The weight of the new fill is expected to result in settlement of the soft to medium stiff silt and clay underlying the site (see additional discussions in Section 5.7, blow). The settlement is time-dependent and is expected to occur over a period of time. Utilities located within the footprint of the roadway embankment should be installed after the consolidation settlement is complete. We performed a quantitative slope stability analysis of the proposed roadway embankment in the static, seismic (pseudo-static), and post-liquefaction conditions. We performed our slope stability analysis using the program SLIDE2 (Slide) by Rocscience Inc. Slide is a two-dimensional limit equilibrium slope stability analysis program. Our analysis used the Janbu Corrected Method to determine potential failure. The following discusses our model and analysis: Soil Parameters: A summary of the input soil parameters is provided in Table 2 below. Input parameters were selected based on general estimates provided in the WSDOT Geotechnical Design Manual, CPT data, and our judgement and experience with similar soils. The undrained residual strength (post-liquefaction) of the Glaciomarine Drift deposit was determined using the methodology described in Section 6-2.2 in the WSDOT Geotechnical Design Manual (2019). The Glaciomarine Drift was divided into three 10-foot-thick layers to more accurately reflect the increased residual strength with depth. Table 2 – SLIDE Soil Input Parameters oil Type Unit Weight (pcf) Friction Angle (degrees) Cohesion (psf) Preload Fill 120 34 0 Existing Fill 120 32 0 Glaciomarine Drift 115 26 150 Glaciomarine Drift (Post-Liquefaction Layer 1) 115 0 230 Glaciomarine Drift (Post-Liquefaction Layer 2) 115 0 250 Glaciomarine Drift (Post-Liquefaction Layer 3) 115 0 266 Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 9 Groundwater: The groundwater table was modeled at the contact between the existing fill and Glaciomarine Drift. Seismic Parameters: Seismic design parameters for the site were developed in conformance with the 2018 IBC, which specifies a design earthquake having a 2 percent probability of occurrence in 50 years (return interval of 2,475 years). A spectral response acceleration was obtained from the USGS Earthquake Hazards Program Interpolated Probabilistic Ground Motion website (2008 data) for the project latitude and longitude, based on Site Class D for stiff soil. We obtained a peak ground acceleration (PGA) of 0.48g. One-half of the PGA, or 0.24g, as used in our slope stability analysis, consistent with the local practice. Results: the results of our slope stability analysis are summarized in the attached Figures 4, 5, and 6, for the static, pseudo-static (seismic), and post-liquefaction. In summary, the calculated minimum global factors of safety for the static, seismic, and post-liquefaction conditions were about 2.78, 1.34, and 1.37, respectively. Based on the results from our analysis, the global stability of the proposed roadway embankment meets the minimum factor of safety requirement of 1.5 for the static condition, 1.1 for the seismic condition, and 1.0 for the post-liquefaction condition. 5.7 SETTLEMENT ESTIMATE AND MONITORING Under the proposed new fill, the soft to medium stiff silt and clay (Soil unit 2) is expected to settle. Based on the general consistency of the soils from the CPTs, we estimate that the settlement from the proposed fill placement should be no more than about 3 to 4 inches. The estimated settlement should occur within about 3 months after placement of the fill. However, we will refine our estimate of the settlement in our upcoming report once our test borings and laboratory test program and engineering analysis are completed. Construction of the proposed improvements such as underground utilities, buildings, pavements should be commenced only after the consolidation settlement of the soft to medium stiff silt and clay has stabilized. A settlement monitoring program should be implemented to confirm that settlement is occurring as expected during preload period and to verify the end of consolidation settlement such that the site can be released for construction. Monitoring of settlements should be performed using settlement plates, placed at a grid spacing of generally no greater than about 100 feet apart, in areas where the site grade will be raised by more than 4 feet. A schematic detail of settlement plate is shown in the attached Figure 7. Other considerations for settlement monitoring are outlined below: Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 10 • The settlement plates should be installed on firm ground prior to placing any fill. Locations of settlement plates should be clearly marked and readily visible (red flagged) to equipment operators. • The contractor should maintain at least a 5-foot horizontal clearance with heavy equipment. Fill within 5 feet of the settlement plates should be compacted with small equipment to project specifications. In the event of damage to a settlement plate or measurement rod, the contractor should immediately notify the geotechnical engineer and should restore the settlement plate to working order. • A licensed land surveyor should be retained to monitor the settlement plates. Initial readings should be taken on top of the measurement rod and at the adjacent ground level prior to fill placement. For ease in handling, the measurement rod and casing can be installed in 5-foot sections. As fill progresses, couplings should be used to install additional lengths. Continuity should be maintained when adding extensions, by reading the top of the measurement rod, then immediately adding the new section and reading the top of the added rod. Both readings should be recorded. • After initial placement, readings should be taken twice weekly during fill placement, once weekly after completion of fill placement for at least 4 weeks. Depending on the project schedule and results of the monitoring, the monitoring frequency may be adjusted by the geotechnical engineer accordingly. • The measurement rod readings should be to the nearest 0.01 foot (or the nearest 0.005 foot if possible); fill elevations should be measured to the nearest 0.1 foot. All elevations should be referenced to a benchmark located on stable ground at least 100 feet from the preload areas. Readings should be submitted in a timely fashion to the geotechnical engineer, who should analyze the settlement data, to provide a basis for determining when the desired effect of preloading has been achieved, and the consolidation settlement has been completed. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 11 5.8 UTILITIES Utilities should be installed after completion of the pre-load, to mitigate the risk of post- construction settlement. 5.8.1 Trench Excavations We anticipate that utilities will be installed after placement of the new fill. As such, utility trench excavations are anticipated to extend through a sequence proposed fill, the existing fill, and soft to medium stiff silt and clay. Temporary excavations greater than 4 feet deep should be properly sloped or shored. All temporary excavations should be performed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for maintaining safe excavation slopes and/or shoring. For planning purposes, the temporary excavations may be sloped as steep as 1H:1V for excavations located above the groundwater table but should be re-evaluated in the field during construction based on actual observed soil conditions. Temporary excavation located below the groundwater table may be sloped as steep as 1.5H:1V, provided the excavation is adequately dewatered. During wet weather, the cut slopes may need to be flattened to reduce potential erosion. Conventional trench shoring systems such as trench boxes or steel sheets with hydraulic bracing may be used to limit the excavation. For design purposes, the contractor may utilize an equivalent fluid weight of 35 pcf to represent the lateral earth pressures on the shoring. This pressure should be increased to 45 pcf for shoring with a maximum 1H:1V backslopes above the shoring. Surcharges from soil stockpiles and/or equipment traffic located within a horizontal distance equal to the depth of the excavation should also be applied to the shoring design. 5.8.2 Dewatering Groundwater is estimated between 6 to 10 feet below the existing grade at the time of our exploration. If excavation extends below the water table, control of groundwater may be necessary. The rate of groundwater discharge will largely depend on the groundwater level at the time of excavation, the depth of excavation, the actual soil conditions (sand vs. silt/clay), and the sequencing of the excavation. However, it is our opinion that the dewatering can likely be accomplished with sumps and pumps. If groundwater is encountered during excavation, the bottom of the excavation should be sloped to one or more shallow sump pits. The collected water can then be pumped from these pits to a Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 12 positive and permanent discharge. Depending on the magnitude of such seepage, it may also be necessary to interconnect the sump pits by a system of connector trenches. 5.8.3 Pipe Bedding Pipe bedding material, placement, compaction, and shaping should be in accordance with the project specifications and the pipe manufacturer’s recommendations. As a minimum, the pipe bedding material should meet the requirements for Gravel Backfill for Pipe Zone Bedding in Section 9-03.12(3) of the WSDOT Standard Specifications (2020). Bedding material should be placed in accordance with the recommendations provided in section 7-08.3(1)C for Pipe Zone Bedding in the WSDOT’s Standard Specifications (2020) to ensure proper pipe support and protection. The excavated trench bottom should be firm and unyielding or be compacted to such a condition prior to placement of bedding material. 5.8.4 Trench Backfill In general, the trench backfill may consist of the existing granular fill that is present at the site, or the import soils that will be used to raise the site grade. The native soils (Soil Unit 2) below the existing fill contain significant amounts of fines and in our opinion not appropriate for use as trench backfill. The placement of trench backfill should be in accordance with Section 7-08.3(3) of WSDOT Standard Specifications (2020). The first zone of backfill extending from the bedding material to at least 6 inches above the crown of the pipe should consist of select free-draining granular material to reduce the compaction effort required and resulting stresses on the pipe. The granular material should be well-graded, less than 1½ inch in maximum size, and less than 10 percent passing the No. 200 sieve, such as Gravel Backfill for Pipe Zone Bedding in section 9-03.12(3) of WSDOT’s Standard Specifications (2020) or CSBC. During placement of the initial lifts, the trench backfill should not be bulldozed into the trench or dropped directly on the pipe. Furthermore, heavy vibratory equipment should not be permitted to operate directly over the pipe until a minimum of 2 feet of backfill has been placed above the crown. The trench backfill material should be placed in 8- to 12-inch, loose lifts and compacted to at least 95% of the Modified Proctor (ASTM D1557). Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 13 5.9 GENERAL EARTHWORK RECOMMENDATIONS 5.9.1 Fill Compaction In general, except in landscaping areas, all fills should be compacted to 95 percent of its maximum dry density, as determined using ASTM D 1557 (Modified Proctor). The procedure to achieve proper density of a compacted fill depends on the size and type of compacting equipment, soil moisture content, the number of passes, thickness of the layer being compacted, and certain soil properties. In areas where the use of heavy equipment may be restricted, smaller equipment can be used, but the soil must be placed in thin enough layers to achieve the required relative compaction. 5.9.2 Wet Weather Earthwork In our opinion, because the site soils generally contain a considerable amount of fines and are considered moisture sensitive, earthwork construction performed during the drier summer months likely will be more economical. If the earthwork will be performed during wet weather, the on- site soils could become saturated and lead to difficult working conditions. In addition, saturated soils could become difficult or impossible to adequately compact. Soft and unstable soil conditions due to inclement weather, disturbance, and poor drainage will require removal and replacement with granular structural fill. To reduce the risks of soil disturbance due to inclement weather conditions, we recommended that, as a minimum, the following recommendations be incorporated into the contract specifications. • Earthwork should be performed in small areas to minimize exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. • The size and type of construction equipment used may have to be limited to prevent soil disturbance. • During wet weather conditions, the allowable fines content of Gravel Borrow should be reduced to no more than 5 percent by weight based on the portion passing ¾-inch sieve. The fines should be non-plastic. • The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 14 • The ground surface within the construction area should be sealed by a smooth drum vibratory roller, or equivalent, and under no circumstances should soil be left uncompacted and exposed to moisture. • Bales of straw and/or geotextile silt fences should be strategically located to control surface water and erosion. 6.0 LIMITATIONS We have prepared this report for Merlino Properties and the project design team. Recommendations contained in this report are based on a site reconnaissance, a subsurface exploration program, review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed-upon scope of work. Variations in soil conditions may exist between the locations of the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors’ methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on-site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 15 It is the client’s responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor’s option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. We appreciate the opportunity to be of service. Sincerely, PanGEO Inc. 2/12/2020 Bryce Townsend, P.E. Siew L. Tan, P.E. Project Geotechnical Engineer Principal Geotechnical Engineer Preliminary Geotechnical Report – Site Grading MJB North Shoreline, Anacortes, Washington February 12, 2021 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. 16 7.0 REFERENCES Boulanger, R.W., Idriss, I.M., 2014, CPT and SPT Based Liquefaction Triggering Procedures, University of California at Davis, Department of Civil & Environmental Engineering. Cetin at al. (2009), Probabilistic Model for the Assessment of Cyclically Induced Reconsolidation (Volumetric) Settlements, Middle East Technical University, 06531, Ankara, Turkey, Department of Civil Engineering. International Code Council, 2018, International Building Code (IBC), 2018. United States Geological Survey, 2008, Earthquake Hazards Program, Interpolated Probabilistic Ground Motion for the Conterminous 48 States by Latitude and Longitude, 2008 Data, accessed via: http://earthquake.usgs.gov/designmaps/us/application.php Washington Administrative Code (WAC), 2013, Chapter 296-155 - Safety Standards for Construction Work, Part N - Excavation, Trenching, and Shoring. WSDOT, 2019, Geotechnical Design Manual, M46-03.12. WSDOT, 2020, Standard Specifications for Road, Bridges, and Municipal Construction. 21-038 1 VICINITY MAP Figure No.Project No. Base Map: Seattle City GIS NORTH Not to Scale Proposed Development MJB North Shoreline Anacortes, Washington Project Site 21 - 0 3 8 F i g . 1 - V i c i n i t y M a p 1 / 2 9 / 2 1 ( 1 : 4 0 : 2 7 ) Notes: 1. See Figure 2 for location of Section A-A'. 2. Ground surface elevations based on the contours shown on Plan Sheet C0.10, dated 8/28/2020, by KPFF. 3. See report text for additional discussions on subsurface conditions. 4. The generalized soil profile is based on widely-spaced probes. Soil conditions may vary over a small distance, and the actual subsurface conditions may be different from the generalized soil profile depicted in this figure. MJB North Shoreline Anacortes, Washington GENERALIZED SUBSURFACE PROFILE A-A' Project No. Figure No. 21-038 3A21 - 0 3 8 F i g . 3 A - S u b s u r f a c e P r o f i l e 2 / 1 2 / 2 1 ( 1 : 3 3 : 1 6 ) Legend: Fill Pre-Olympia Glacial Till (Qpogt) Pre-Olympia Fine-Grained Deposits (Qpof) PG-5 Graphics Legend 48 21 50/5 88 31 42 31 50/3 SPT N-valueGroundwater Level Soil Unit Boundaries Topographic Surface -100 -50 0 50 100 150 200 250 300 350 400 450 500 550 Distance (ft) -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 0 200 400 Qt (tsf)0 200 400 Qt (tsf) ? A A' Approx. Scale: 1" : 50' R Ave PLExisting Building Unit 1 - Existing Fill Unit 2 - Glaciomarine Drift Unit 3 - Glaciomarine Outwash Sand Soil Unit Legend: 0 40 80 120160200 Qt (tsf) Graphics Legend Cone Tip Resistance GroundwaterLevel Soil Unit Boundaries CPT # Topographic Surface 100' SETBACK FROM SHORELINEADJACENT WEST PROPERTY EXISTING BUILDING ~20' S OFFSET CPT-3 ~10' N OFFSET CPT-4?? ??? ? ?? ?? ? ? ?? ? ? ?? Notes: 1. See Figure 2 for location of Section B-B'. 2. Ground surface elevations based on the contours shown on Plan Sheet C0.10, dated 8/28/2020, by KPFF. 3. See report text for additional discussions on subsurface conditions. 4. The generalized soil profile is based on widely-spaced probes. Soil conditions may vary over a small distance, and the actual subsurface conditions may be different from the generalized soil profile depicted in this figure. MJB North Shoreline Anacortes, Washington GENERALIZED SUBSURFACE PROFILE B-B' Project No. Figure No. 21-038 3B21 - 0 3 8 F i g . 3 A - S u b s u r f a c e P r o f i l e 2 / 1 2 / 2 1 ( 1 : 3 2 : 4 3 ) Legend: Fill Pre-Olympia Glacial Till (Qpogt) Pre-Olympia Fine-Grained Deposits (Qpof) PG-5 Graphics Legend 48 21 50/5 88 31 42 31 50/3 SPT N-valueGroundwater Level Soil Unit Boundaries Topographic Surface 0 100 200 300 400 500 600 700 800 900 1000 Distance (ft) -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 -100 -80 -60 -40 -20 0 20 40 60 El e v a t i o n ( f t ) - N A V D 8 8 0 200 400 Qt (tsf) 0 200 400 Qt (tsf)0 200 400 Qt (tsf) 0 200 400 Qt (tsf) B B' Approx. Scale: 1" : 50' R Ave PLExisting Building Unit 1 - Existing Fill Unit 2 - Glaciomarine Drift Unit 3 - Glaciomarine Outwash Sand Soil Unit Legend: 0 40 80 120160200 Qt (tsf) Graphics Legend Cone Tip Resistance GroundwaterLevel Soil Unit Boundaries CPT # Topographic Surface 100' SETBACK FROM SHORELINE Q AVE EXISTINGBUILDING ~160' N OFFSET CPT-10 ~200' S OFFSETCPT-7~80' N OFFSETCPT-8 ~90' N OFFSETCPT-9 FIDALGO BAY?? ??? ? ?? ?? ? ? ?? ? Phi (deg) Cohesion (psf) Strength Type Unit Weight (lbs/ft3)ColorMaterial Name 340Mohr‐ Coulomb120Preload Fill 320Mohr‐ Coulomb120Existing Fill 26150Mohr‐ Coulomb115Glaciomarine Drift Global Minimums Method: Janbu Corrected FS: 2.78 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 60 40 20 0 -2 0 0 20 40 60 80 100 120 Figure No.4Project No.21-038 SLOPE STABILITY ANALYSIS STATIC CONDITION Project MJB North Shoreline Anacortes, Washington SLIDEINTERPRET 9.008 W Phi (deg) Cohesion (psf) Strength Type Unit Weight (lbs/ft3) ColorMaterial Name 340Mohr‐ Coulomb120Preload Fill 320Mohr‐ Coulomb120Existing Fill 26150Mohr‐ Coulomb115Glaciomarine Drift Global Minimum Method: Janbu Corrected FS: 1.337 0.24 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 40 20 0 -2 0 0 20 40 60 80 100 120 Figure No.5Project No.21-038 SLOPE STABILITY ANALYSIS PSEUDO-STATIC CONDITION Project MJB North Shoreline Anacortes, Washington SLIDEINTERPRET 9.008 W Phi (deg) Cohesion (psf) Strength Type Unit Weight (lbs/ ft3)ColorMaterial Name 340Mohr‐ Coulomb120Preload Fill 320Mohr‐ Coulomb120Existing Fill 0230Mohr‐ Coulomb115Post‐Liq 1 0250Mohr‐ Coulomb115Post‐Liq 2 0266Mohr‐ Coulomb115Post‐Liq 3 Global Minimum Method: Janbu Corrected FS: 1.368 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ 40 20 0 -2 0 0 20 40 60 80 100 120 Figure No.6Project No.21-038 SLOPE STABILITY ANALYSIS POST-LIQUEFACTION CONDITION Project MJB North Shoreline Anacortes, Washington SLIDEINTERPRET 9.008 Figure No.Project No. NOTES: 1.Locations of settlement plates shall be clearly marked and readily visible to equipment operators. 2.Contractor shall maintain at least 5 feet of horizontal clearance for heavy equipment from the base of settlement plates. Fill within 5 feet of settlement plates shall be compacted using hand operated equipment. 3.In the event of damage to settlement plates, contractor shall immediately notify Engineer and shall be responsible for restoring the settlement plates to working order. 4.Install plates on firm ground or on sand pads if needed for stability. Take initial readings on top of the rod and at adjacent ground level prior to placement of fill. 5.For ease in handling, rod and casing are usually installed in short sections. As fill progresses, couplings are used to installed additional lengths. Continuity is maintained by reading the top of the measurement rod, then immediately adding the new section and reading the top of the added rod. Both readings should be recorded. 6.Record the elevations of the top of the measurement rod at pre- determined time intervals, but no less than once a week. Each time, note the elevation of the adjacent ground surface. 7.Read the measurement rods to the nearest 0.01 ft, or 0.005 ft if possible. Note the fill elevation to the nearest 0.1 ft. 8.The elevations should be referenced to a temporary benchmark located on stable ground at least 100 feet from the zone of influence of the embankment and surcharge (preload fill). MJB North Shoreline Anacortes, Washington 21-038 7 SETTLEMENT PLATE DETAIL 21-038 MJB North Shoreline - Earthwork Report SLT.docx PanGEO, Inc. APPENDIX A SUMMARY CPT LOGS 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 08:31 Site: Anacortes MJB Shoreline Sounding: CPT-1 Cone: 529:T1500F15U35 Max Depth: 19.550 m / 64.14 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP01.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50495 Long: -122.60883 UndefinedStiff Sand to Clayey SandStiff Sand to Clayey Sand Stiff Sand to Clayey Sand Sand Mixtures Silt Mixtures Clays Silt MixturesSand MixturesSand Mixtures Silt Mixtures Clays Silt Mixtures Sand Mixtures Silt MixturesClaysSilt MixturesStiff Sand to Clayey Sand Very Stiff Fine Grained Stiff Sand to Clayey Sand Sand MixturesSand Mixtures Sand Mixtures Sands Sand Mixtures Sand MixturesVery Stiff Fine GrainedSand MixturesSand Mixtures Stiff Sand to Clayey Sand 35.2 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 09:52 Site: Anacortes MJB Shoreline Sounding: CPT-2 Cone: 529:T1500F15U35 Max Depth: 27.450 m / 90.06 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP02.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50495 Long: -122.60721 Undefined Sand Mixtures Silt Mixtures Sand MixturesSilt Mixtures Silt MixturesSilt Mixtures Sand Mixtures Silt Mixtures Silt Mixtures Sand MixturesSilt MixturesSilt MixturesStiff Sand to Clayey Sand Stiff Sand to Clayey SandVery Stiff Fine GrainedStiff Sand to Clayey SandStiff Sand to Clayey SandStiff Sand to Clayey Sand Stiff Sand to Clayey SandStiff Sand to Clayey Sand Sand Mixtures Sand Mixtures Sand Mixtures Stiff Sand to Clayey Sand Sand Mixtures Very Stiff Fine GrainedStiff Sand to Clayey Sand Very Stiff Fine Grained Sand Mixtures Very Stiff Fine Grained Silt Mixtures Sand Mixtures Silt Mixtures Sand MixturesSilt Mixtures Sand Mixtures Sands Sand Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Undefined 14.4 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 12:06 Site: Anacortes MJB Shoreline Sounding: CPT-3 Cone: 529:T1500F15U35 Max Depth: 23.575 m / 77.34 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP03.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50571 Long: -122.60880 Undefined Stiff Sand to Clayey SandSilt Mixtures Sand Mixtures Very Stiff Fine Grained Stiff Sand to Clayey SandSilt Mixtures Silt MixturesSand Mixtures Sand MixturesSand Mixtures Sand Mixtures Sand Mixtures Silt Mixtures Sand MixturesSilt Mixtures Sand MixturesSand MixturesSilt MixturesStiff Sand to Clayey Sand Sands Sand Mixtures Sands SandsSand MixturesSands Sand Mixtures Sands Sand MixturesSand MixturesSands Sands Sand Mixtures Undefined 3.6 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 03:28 Site: Anacortes MJB Shoreline Sounding: CPT-4 Cone: 529:T1500F15U35 Max Depth: 24.050 m / 78.90 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP04.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50590 Long: -122.60744 Undefined SandsSand MixturesSands Silt Mixtures ClaysClays Silt Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Clays Silt Mixtures Sand MixturesSands Sands Sands Sand MixturesSand Mixtures Sands Very Stiff Fine Grained Very Stiff Fine GrainedStiff Sand to Clayey Sand SandsStiff Sand to Clayey Sand Sands Stiff Sand to Clayey Sand SandsSand MixturesSand Mixtures Sands Sands Sand Mixtures Sand Mixtures Sands Sand Mixtures Sand Mixtures Sand Mixtures 3.7 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-01 04:49 Site: Anacortes MJB Shoreline Sounding: CPT-5 Cone: 529:T1500F15U35 Max Depth: 29.675 m / 97.36 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP05.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50675 Long: -122.61047 Undefined Silt Mixtures Sand Mixtures Silt MixturesStiff Sand to Clayey Sand Silt Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Silt Mixtures Silt Mixtures Clays Silt MixturesSand Mixtures Silt MixturesSand Mixtures Sand MixturesStiff Sand to Clayey SandStiff Sand to Clayey Sand Sand Mixtures Stiff Sand to Clayey Sand SandsSand Mixtures Sand MixturesStiff Sand to Clayey Sand Very Stiff Fine GrainedSands Sand Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Very Stiff Fine Grained Sand Mixtures Silt MixturesSilt Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Sands Silt Mixtures Sand Mixtures Undefined Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 08:16 Site: Anacortes MJB Shoreline Sounding: CPT-6 Cone: 529:T1500F15U35 Max Depth: 17.100 m / 56.10 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP06.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50700 Long: -122.60816 Undefined Gravelly Sand to SandGravelly Sand to Sand Gravelly Sand to SandStiff Sand to Clayey Sand Sand MixturesSilt MixturesSilt MixturesSand Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Silt Mixtures ClaysClaysVery Stiff Fine Grained Sand MixturesSands Stiff Sand to Clayey SandSand Mixtures Sand Mixtures Stiff Sand to Clayey Sand Sand Mixtures Very Stiff Fine GrainedSilt Mixtures Very Stiff Fine GrainedSand MixturesSilt Mixtures Sand MixturesSand Mixtures Sand Mixtures Silt Mixtures Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 09:14 Site: Anacortes MJB Shoreline Sounding: CPT-7 Cone: 529:T1500F15U35 Max Depth: 22.950 m / 75.29 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_SP07.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50767 Long: -122.60973 UndefinedGravelly Sand to Sand Sands Silt Mixtures Sand MixturesSilt MixturesSilt MixturesSilt Mixtures Silt Mixtures Clays Very Stiff Fine GrainedSand MixturesSand MixturesStiff Sand to Clayey Sand SandsVery Stiff Fine GrainedSand Mixtures Sand MixturesStiff Sand to Clayey SandSand Mixtures Sand Mixtures Sand MixturesStiff Sand to Clayey Sand Sand Mixtures Sands SandsSilt Mixtures Sand Mixtures Sands Sand MixturesSilt Mixtures Sand Mixtures Very Stiff Fine Grained Sand Mixtures Silt Mixtures Sand Mixtures Undefined 27.0 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 10:57 Site: Anacortes MJB Shoreline Sounding: CPT-8 Cone: 529:T1500F15U35 Max Depth: 21.925 m / 71.93 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP08.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50843 Long: -122.61024 UndefinedSand MixturesSand MixturesSilt Mixtures Sand MixturesSilt Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Silt Mixtures Clays Silt Mixtures Sand MixturesSands Silt MixturesSand Mixtures Sand Mixtures Sands Sand Mixtures Sands Sand MixturesSands Silt Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Undefined 34.6 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 02:06 Site: Anacortes MJB Shoreline Sounding: CPT-9 Cone: 529:T1500F15U35 Max Depth: 22.125 m / 72.59 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP09.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50842 Long: -122.60853 Undefined Sands Sand Mixtures Silt Mixtures Sand MixturesSand MixturesSilt MixturesSilt Mixtures Silt Mixtures Silt MixturesClaysSilt MixturesSand Mixtures Silt Mixtures Silt Mixtures Sand MixturesSand Mixtures Sand MixturesSand MixturesStiff Sand to Clayey SandVery Stiff Fine Grained Very Stiff Fine Grained Sand MixturesSandsSand Mixtures SandsStiff Sand to Clayey Sand SandsSand Mixtures SandsSands SandsStiff Sand to Clayey Sand Sands Sand Mixtures Sands Sand Mixtures Sand Mixtures Sands Sand Mixtures Sands Sands Sand Mixtures 24.7 33.3 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched 0 200 400 600 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 qt (tsf) De p t h ( f e e t ) 0.0 5.0 10.0 15.0 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 2000 40000 u (ft) 0 3 6 9 SBT Qtn PanGEO Job No: 21-59-21870 Date: 2021-02-08 03:36 Site: Anacortes MJB Shoreline Sounding: CPT-10 Cone: 529:T1500F15U35 Max Depth: 20.075 m / 65.86 ft Depth Inc: 0.025 m / 0.082 ft Avg Int: Every Point File: 21-59-21870_CP10.COR Unit Wt: SBTQtn (PKR2009) SBT: Robertson, 2009 and 2010 Coords: Lat: 48.50862 Long: -122.60761 Undefined SandsVery Stiff Fine GrainedSand MixturesSand Mixtures Sands SandsSilt Mixtures Silt Mixtures Sand Mixtures Silt MixturesSilt MixturesSilt MixturesSand Mixtures Sand MixturesSands Silt MixturesSand Mixtures Sand MixturesSand MixturesSilt MixturesSands Stiff Sand to Clayey SandSand Mixtures Stiff Sand to Clayey Sand Sand Mixtures Silt Mixtures Sand Mixtures Sands Sand Mixtures Sands Sand MixturesSandsSand Mixtures Sand Mixtures Undefined 3.7 30.4 59.5 Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Dissipation, Ueq assumed Hydrostatic Line The reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. Pre-Punched Pre-Punched Pre-Punched Pre-Punched Job No:21-59-21870 Client:PanGEO Project:Anacortes MJB Shoreline Start Date:01-Feb-2021 End Date:01-Feb-2021 CPTu PORE PRESSURE DISSIPATION SUMMARY Sounding ID File Name Cone Area (cm2) Duration (s) Test Depth (ft) Estimated Equilibrium Pore Pressure Ueq (ft) Calculated Phreatic Surface (ft) Estimated Phreatic Surface (ft) t50 1 (s) Assumed Rigidity Index Value (Ir) ch 2 (cm2/min) CPT-1 21-59-21870_CP01.ppd2 15 430 41.7 35.3 6.4 CPT-1 21-59-21870_CP01.ppd2 15 155 45.1 CPT-1 21-59-21870_CP01.ppd2 15 100 52.2 CPT-1 21-59-21870_CP01.ppd2 15 46 59.0 CPT-1 21-59-21870_CP01.ppd2 15 38 64.1 CPT-2 21-59-21870_CP02.ppd2 15 420 8.0 CPT-2 21-59-21870_CP02.ppd2 15 1230 20.0 14.4 5.6 27 100 26.1 CPT-2 21-59-21870_CP02.ppd2 15 50 90.1 CPT-3 21-59-21870_CP03.ppd2 15 7200 10.0 3.6 6.4 1089 100 0.6 CPT-3 21-59-21870_CP03.ppd2 15 38 77.3 CPT-4 21-59-21870_CP04.ppd2 15 300 9.4 3.7 5.6 CPT-4 21-59-21870_CP04.ppd2 15 36 78.9 Total Duration 167.4 min 1. Time is relative to where umax occurred. 2. Houlsby and Teh, 1991. Sheet 1 of 1 0 150 300 450 600 0 50 100 150 200 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 08:31 Site:Anacortes MJB Shoreline Sounding:CPT-1 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP01.ppd2 Depth:12.700 m / 41.666 ft Duration:430.0 s u Min:35.3 ft u Max:164.9 ft u Final:35.3 ft WT: 1.952 m / 6.404 ft Ueq:35.3 ft 0 400 800 1200 1600 0 150 300 450 600 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 09:52 Site:Anacortes MJB Shoreline Sounding:CPT-2 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP02.ppd2 Depth:6.100 m / 20.013 ft Duration:1230.0 s u Min:29.2 ft u Max:533.5 ft u Final:29.2 ft WT: 1.714 m / 5.623 ft Ueq:14.4 ft U(50):273.96 ft T(50):26.9 s Ir:100 Ch:26.1 cm²/min 0 2000 4000 6000 8000 0 75 150 225 300 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 12:06 Site:Anacortes MJB Shoreline Sounding:CPT-3 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP03.ppd2 Depth:3.050 m / 10.006 ft Duration:7200.0 s u Min:20.3 ft u Max:292.2 ft u Final:20.3 ft WT: 1.952 m / 6.404 ft Ueq:3.6 ft U(50):147.93 ft T(50):1088.9 s Ir:100 Ch:0.6 cm²/min 0 100 200 300 400 0.0 3.0 6.0 9.0 0.0 -3.0 Time (s) Po r e P r e s s u r e ( f t ) PanGEO Job No:21-59-21870 Date:02/01/2021 03:28 Site:Anacortes MJB Shoreline Sounding:CPT-4 Cone:529:T1500F15U35 Area=15 cm² Trace Summary: Filename:21-59-21870_CP04.ppd2 Depth:2.850 m / 9.350 ft Duration:300.0 s u Min:-2.5 ft u Max:6.8 ft u Final:3.8 ft WT: 1.714 m / 5.623 ft Ueq:3.7 ft MJB Properties – Anacortes Development Preliminary Infiltration Report CGS Project No. 19057 Prepared for MJB Properties Prepared by Coastal Geologic Services, Inc. Contributors/Authors: Brendan P. Moran, PE November 27, 2019 DR A F T COASTAL GEOLOGIC SERVICES, INC. 1711 Ellis St. Suite 103, Bellingham, WA 98225 (360) 647-1845 www.coastalgeo.com Introduction and Existing Conditions This report presents the results of our Preliminary Infiltration Investigation for the MJB Properties Anacortes Development. The purpose of our investigation was to characterize subsurface conditions and provide preliminary design infiltration rates for the proposed development. The project site is composed of numerous parcels east of Q Avenue roughly between 17th Street and 22nd Street in Anacortes, Washington (See Figure 1, Site Map) totaling approximately 29 acres and including:  Parcel B: P32963  Parcel C: P32965  Parcel D: P32966  Parcel E: P32967  Parcel F: P32968  Parcel G: P32969  Parcel H: P32970  Parcel I: P32971  P32913  P32915  P32916  P32929  P32941  P32943  P78000 The site is bordered on the south by the Anacortes Marina and 22nd Street, on the north by Seafarers Memorial Park and various commercial buildings and paved parking, and on the east by Fidalgo Bay. Most of the subject properties are minimally developed, although extensive shoreline backfilling and dredging has been conducted over a majority of the area. The Northern Marine boat building company operates out of an industrial building in the southwestern portion of the site, close to several other storage and industrial buildings located along a spur of R Avenue. The northeastern portion of the site was previously occupied by Scott Paper Mill, which has since been demolished. We understand that former paper mill operations resulted in soil contamination, and that multiple soil remediation projects have been conducted in the area. Assessment of soil contaminants and associated mitigations are outside the scope of this infiltration investigation. Proposed Construction Based on a conceptual site plan provided by KPFF Consulting Engineers, the proposed construction consists of various multi‐family residences, retail buildings, a hotel and event center, and restaurants with associated paved access drives and parking areas. Potential stormwater management facilities may include raingardens and detention ponds. Based on conversations with project civil engineer Kyle Carrick of KPFF, we understand that captured runoff that cannot be infiltrated will ultimately be discharged to Fidalgo Bay following appropriate water quality control. DR A F T MJB Properties – Anacortes Development – Preliminary Infiltration Report November 27, 2019, p. 2 COASTAL GEOLOGIC SERVICES, INC. Subsurface Exploration and Soil Testing Subsurface conditions were investigated by excavating eight exploratory test pits on November 8, 2019 with a mini‐excavator and operator provided by the client. Test pits were advanced to depths of 7 to 8 FT below ground surface (BGS). Soils generally consisted of 2 to 6.5 FT of fill material overlying very stiff to hard clay and clayey sand interpreted as native glaciomarine drift. The overlying fill material was variously composed of crushed rock top course, construction rubble and debris, and a moderately organic silt/clay that was presumed to be dredged material from historic backfilling at the shoreline. More detailed descriptions of the subsurface conditions encountered in our test pits are provided on our Exploration Logs, Figures A‐1 and A‐2. Geologic Conditions Geologic mapping of the project area was obtained from the Geologic Map of the Bellingham 1:100,000 Quadrangle (Lapen, 2000). The surficial geology of the site is mapped as artificial fill (Qf), concurrent with the surface layer of fill material identified in our test pit explorations. The upland area west of Q Avenue is mapped as glaciomarine drift (Qgdme), described as moderately to unsorted diamicton containing lenses and discontinuous beds of moderately to well‐sorted gravel, sand, silt and clay with variable dropstone content. These soils were deposited 11,300 to 13,500 years ago from melting glacial ice floating in seawater. The low‐energy depositional environment permitted fine particles to settle out of suspension, contributing to clay and silt beds such as those observed during our test pit explorations. Thus, the native soils encountered below the fill in our explorations closely concur with the unit of glaciomarine drift that is mapped adjacent to the site. Groundwater Slight to moderate groundwater seeps were observed in five of the eight test pit explorations at depths of approximately 2.75 to 3.25 FT BGS. The observed seepage was identified as lateral movement of water atop stratigraphic contacts with finer‐grained, denser, lower‐permeability soil, and thus reflects a “perched” water condition rather than a true regional groundwater aquifer at this depth. Nonetheless, seasonal perched groundwater may affect infiltration facilities and will likely be encountered during excavations at this site. Groundwater levels are influenced by seasonal variations in precipitation, changes in runoff patterns due to development and other factors. The groundwater levels recorded on our exploration logs are representative of the time and location of each exploration, and may not be representative of conditions at other times and locations. Results and Discussion Infiltration The 2019 Stormwater Management Manual for Western Washington (SWMMWW) provides Site Suitability Criteria (SSC) for siting infiltration facilities. SSC‐6 indicates that uncontrolled fill materials are unsuitable as infiltration media. Thus, infiltration facilities at this site will be required to bottom into native soils. The SWMMWW provides a methodology for estimating infiltration rates based on the grain‐size distribution of the infiltration soils. This methodology assumes a relatively loose soil consistency and does not account for stiff/dense, compact in‐situ soil conditions such as those observed in the native DR A F T MJB Properties – Anacortes Development – Preliminary Infiltration Report November 27, 2019, p. 3 COASTAL GEOLOGIC SERVICES, INC. glaciomarine drift at this site. Thus, the grain‐size distribution method would not be suitable for estimating a design infiltration rate at this site. Due to the relatively stiff consistency and fine‐grained particle size, it is our opinion that the native glaciomarine drift is effectively impervious and not suitable for infiltration. The presence of shallow, perched groundwater seeps reinforces this assessment. We recommend that stormwater runoff at this site be properly detained, treated, and discharged to an applicable storm sewer system, Fidalgo Bay, or another appropriate outfall as specified by the project civil engineer. Stormwater Treatment For BMPs that will use native soil to provide runoff treatment, SSC‐6 of the SWMMWW specifies a minimum cation exchange capacity (CEC) of 5 meq/100 grams and minimum organic content of 1.0 percent. Three samples of the native glaciomarine drift were sent to Northwest Agricultural Consultants for testing. Results are summarized in Table I below. Table 1. CEC/OC test results. Sample Organic Content Cation Exchange Capacity (meq/100g) TP-1 @ 4 FT 1.65% 17.8 TP-3 @ 5 FT 2.20% 21.0 TP-7 @ 2.5 FT 2.17% 23.7 Based on the test results and minimum requirements of SSC‐6, the native glaciomarine drift soils are suitable for reuse as filtration media in stormwater treatment BMPs. Limitations of This Report This report was prepared for the specific conditions present at the subject property to meet the needs of specific individuals. No one other than the landowner and their agents should apply this report for any purposes other than that originally contemplated without first conferring with the geologist or geotechnical engineer that prepared this report. The findings and recommendations presented in this report were reached based on site visits and subsurface exploration with visual assessment of site soils. Conditions may change at the site due to human influences, floods, groundwater changes, or other factors. This report may not be all that is required to carry out recommended actions. More detailed design specifications may be needed for proper design of potential infiltration facilities or drainage features. We appreciate the opportunity to work with you on this project. Please do not hesitate to contact us with any questions or concerns. References Lapen, TJ. 2000. Geologic Map of the Bellingham 1:100,000 Quadrangle, Washington. Washington State Department of Natural Resources. OFR 2000‐5. Washington State Department of Ecology. July 2019. Stormwater Management Manual for Western Washington. Publication Number 19‐10‐021. DR A F T MJB Properties – Anacortes Development – Preliminary Infiltration Report November 27, 2019, p. 4 COASTAL GEOLOGIC SERVICES, INC. Coastal Geologic Services Inc. DRAFT Brendan P. Moran, PE Geotechnical Engineer ATTACHMENTS:  Figure 1 – Site Map  Figures A‐1 and A‐2 – Exploration Logs DR A F T TP-7 TP-8 TP-6 TP-5 TP-4 TP-3 TP-1 TP-2 Historic Shoreline per Washington DoE Coastal Zone Atlas Conceptual site plan provided by KPFF consulting engineers LEGEND Approximate location of Test Pit exploration TP-1 0200'100' 200' 400' 1"=200' R: \ S k a g i t C o u n t y \ M J B P r o p e r t i e s An a c o r t e s \ G e o t e c h \ F i g u r e s \ M J B A n a c o r t e s L o g s COASTAL GEOLOGIC SERVICES 1711 Ellis St, Suite 103 Bellingham, WA 98225 360-647-1845 - coastalgeo.com Figure # N Client:MJB Properties CGS Project No. 19057 Date: 11/27/2019 1SITE AND EXPLORATION PLAN MJB ANACORTES DEVELOPMENT INFILTRATION INVESTIGATION DR A F T TP-1 Terminal Depth - 7 ft No groundwater seepage observed 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM USCS Depth (ft) SC CL SAND, GRAVEL, COBBLE; relatively clean to silty with depth, angular, slightly moist, dark brown to gray, dense (Fill) Description SAND; very clayey/silty, wet, gray-brown, medium dense (Glaciomarine Drift) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) TP-2 Terminal Depth - 7 ft Moderate groundwater seep @ 3 ft 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM USCS Depth (ft) CL/ FILL SC SAND, GRAVEL, COBBLE; angular boulders in upper 2 ft, relatively clean to silty with depth, angular, dry to moist with depth, gray to red-gray, dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) SAND; very clayey/silty, wet, gray-brown, medium dense (Glaciomarine Drift) TP-3 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-4 Terminal Depth - 7 ft No groundwater seepage observed 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM USCS Depth (ft) GC/ FILL GP/ FILL SAND & GRAVEL; clayey, scattered wood and organics, moist, gray, dense (Fill) Description CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift)Terminal Depth - 7 ft Moderate groundwater seep @ 3 ft USCS GP/GM FILL CL/ FILL CL SAND, GRAVEL, COBBLE; relatively clean to silty with depth, angular, dry to moist with depth, gray to red-gray, dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) GP/GM FILL GP/GM FILL GRAVEL; sandy, angular, scattered rootlets in upper 6 inches, scattered brick/concrete/ rubble throughout, brown to gray, slightly moist, dense (Fill) CL R: \ S k a g i t C o u n t y \ M J B P r o p e r t i e s An a c o r t e s \ G e o t e c h \ F i g u r e s \ M J B A n a c o r t e s L o g s COASTAL GEOLOGIC SERVICES 1711 Ellis St, Suite 103 Bellingham, WA 98225 360-647-1845 - coastalgeo.com Figure # A-1 Client:MJB Properties CGS Project No. 19057 Date: 11/27/2019 EXPLORATION LOGS MJB ANACORTES DEVELOPMENT INFILTRATION INVESTIGATION DR A F T TP-5 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-6 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-7 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) TP-8 5 10 15 0 Exploration Date: 11/8/2019 Exploration Contractor: Client Provided Logged by: BPM Depth (ft) Terminal Depth - 7.5 ft Slight groundwater seep @ 3 ft USCS GP/ FILL CL/ FILL SAND, GRAVEL, COBBLE; relatively clean, dry to moist with depth, gray, medium dense to dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) CL Terminal Depth - 7.5 ft Slight groundwater seep @ 3.25 ft USCS GP/ FILL CL/ FILL SAND, GRAVEL, COBBLE; rounded, relatively clean, scattered wood and organics, moist, gray, dense (Fill) Description CLAY & SILT; sandy, scattered wood and organics, wet, gray-black, medium stiff to stiff (Dredged Fill) CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) CL Terminal Depth - 8 ft No groundwater seepage observed USCS CL SAND, GRAVEL, COBBLE; angular, silty, moist, gray to brown, very dense (Fill) Description CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) GP/GM FILL Terminal Depth - 8 ft Very slight groundwater seep @ 2.75 ft USCS CL SAND, GRAVEL, COBBLE; angular, silty, moist, gray to brown, very dense (Fill) Description CLAY; slightly sandy with occasional gravel and cobble dropstones, moist, gray with scattered orange-brown oxidation, very stiff to hard (Glaciomarine Drift) GP/GM FILL R: \ S k a g i t C o u n t y \ M J B P r o p e r t i e s An a c o r t e s \ G e o t e c h \ F i g u r e s \ M J B A n a c o r t e s L o g s COASTAL GEOLOGIC SERVICES 1711 Ellis St, Suite 103 Bellingham, WA 98225 360-647-1845 - coastalgeo.com Figure #Client: MJB Properties CGS Project No. 19057 Date: 11/27/2019 EXPLORATION LOGS MJB ANACORTES DEVELOPMENT INFILTRATION INVESTIGATION A-2 DR A F T MJB North Roadway –MJB Properties Appendix 3 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. We propose to provide this information in a deferred submittal. DEFERRED SUBMITTAL: PROVIDE A TEST REPORT FROM SOILS SUPPLIER TO THE ENGINEERING DEPT. PROJECT INFORMATION “Model Soil Management Plan for BMP T5.13” age # ____ of ____ pages Complete all information on page 1; only site address and permit number on additional pages. Site Address / Lot No.:______________________________________________________________________________ Permit Type: Permit Number: Permit Holder: Phone: Mailing Address:__________________________________________________________________________________ Contact Person: Phone: Plan Prepared By: 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 proposed 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 ___ Subsoil will be scarified ___ inches (depth) of scarification needed to achieve finished total 12” loosened depth. PRE-APPROVED AMENDMENT METHOD: ___ Topsoil import ___ Amend with compost ___ Stockpile and amend ( ____ cu. yds. stockpiled) ____inches of compost or imported topsoil applied X 3.1 (conversion factor, inches to cubic yards) _____= cu. yards per 1,000 sq. ft. X ___ ,000s sq.ft. in this area ____ = cubic yards of amendment → → → → → (needed to cover this area to designated depth) PRODUCT:_________________________ __________________________________ QUANTITY:________CU. YDS. CUSTOM AMENDMENT ___ Topsoil import ___ Topsoil & compost lift ___ Amend ___ Stockpile and amend (____ cu. yds. stockpiled) Attach test results and calculations. ____ inches organic matter or topsoil import X 3.1 _____= cu. yards / 1,000 sq. ft. X ___ ,000s sq.ft. in this area ____ = cubic yards of amendment → → → → → PRODUCT:_________________________ __________________________________ QUANTITY:________CU. YDS. MULCH ___ ,000 sq.ft. X 6.2 (conversion, to give 2 inch mulch depth) ____ = cubic yards of mulch → → → → → → PRODUCT:_________________________ QUANTITY:________CU. YDS. TOTAL AMENDMENT/TOPSOIL/MULCH FOR ALL AREAS (complete on page 1 only, totaling all areas/pages in this Plan)  Product #1:__________________________________________  Quantity: _________cu. yds.  Test Results: ___ % organic matter ____C:N ratio <25:1 (except mulch, or <35:1 for native plants) ____ “stable” (yes/no)  Product #2:__________________________________________  Quantity: _________cu. yds.  Test Results: ___ % organic matter ____C:N ratio <25:1 (except mulch, or <35:1 for native plants) ____ “stable” (yes/no)  Product #3:__________________________________________  Quantity: _________cu. yds.  Test Results: ___ % organic matter ____C:N ratio <25:1 (except mulch, or <35:1 for native plants) ____ “stable” (yes/no) Date: Inspector: Approved: Revisions Required: Date: Inspector: Approved: Revisions Required: MJB North Roadway –MJB Properties Appendix 4 Appendix 4 Runoff Treatment Calculations ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.58 Program License Number: 200410007 Project Simulation Performed on: 07/12/2023 6:19 PM Report Generation Date: 07/12/2023 6:35 PM ————————————————————————————————— Input File Name: MJB P Plat WQ.fld Project Name: MJB WQ Analysis Title: Comments: P Plat Largest Parcel ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Full Period of Record Available used for Routing Climatic Region Number: 12 Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : Ecology Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 1.667 1.667 Area of Links that Include Precip/Evap (acres) 0.000 0.119 Total (acres) 1.667 1.786 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : largest parcel PGIS ---------- -------Area (Acres) -------- ROADS/MOD 1.667 ---------------------------------------------- Subbasin Total 1.667 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Largest parcel PGIS ---------- -------Area (Acres) -------- ROADS/MOD 1.667 ---------------------------------------------- Subbasin Total 1.667 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Copy Lnk1 Link Type: Copy Downstream Link: None ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ------------------------------------------ Link Name: New Copy Lnk1 Link Type: Copy Downstream Link: None ------------------------------------------ Link Name: Non-Infiltrating Bioretention Link Type: Ecology Bioretention Facility Downstream Link: None Floor Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 101.50 Storage Depth (ft) : 1.50 Bottom Length (ft) : 520.0 Bottom Width (ft) : 10.0 Bottom Slope (ft/ft) : 0.000 Side Slopes (ft/ft) : Z1= 0.00 Z2= 0.00 Z3= 0.00 Z4= 0.00 Bottom Area (sq-ft) : 5200. Area at Riser Crest El (sq-ft) : 5,200. (acres) : 0.119 Volume at Riser Crest (cu-ft) : 7,800. (ac-ft) : 0.179 Infiltration on Bottom only Selected Soil Properties Layer No Soil Name Thickness (ft) 1 ASTM 100 0.250 2 SMMWW 12 in/hr (Ecol 1.500 3 GRAVEL 1.500 KSat Safety Factor: 4.0 Native Soil Infiltration Rate (in/hr) : 0.00 Underdrain Present Underdrain Offset (in): : 6.00 Orifice Diameter (in) : 0.000 Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 101.50 ft Hydraulic Structure Geometry Number of Devices: 0 ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 1 ********** Link: New Copy Lnk1 ********** 2-Year Discharge Rate : 0.614 cfs 15-Minute Timestep, Water Quality Treatment Design Discharge On-line Design Discharge Rate (91% Exceedance): 0.23 cfs Off-line Design Discharge Rate (91% Exceedance): 0.13 cfs Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 197.96 Inflow Volume Including PPT-Evap (ac-ft): 197.96 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 197.96 Secondary Outflow To Downstream System (ac-ft): 0.00 Volume Lost to ET (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered+ET)/Total Volume: 0.00% ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ********** Link: Non-Infiltrating Bioretention ********** Basic Wet Pond Volume (91% Exceedance): 5178. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 7768. cu-ft 2-Year Discharge Rate : 0.353 cfs 15-Minute Timestep, Water Quality Treatment Design Discharge On-line Design Discharge Rate (91% Exceedance): 0.23 cfs Off-line Design Discharge Rate (91% Exceedance): 0.13 cfs Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 197.96 Inflow Volume Including PPT-Evap (ac-ft): 211.61 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 203.81 Secondary Outflow To Downstream System (ac-ft): 0.00 Volume Lost to ET (ac-ft): 7.80 Percent Treated (Infiltrated+Filtered+ET)/Total Volume: 3.69% WQ volume required in a non-infiltrating bioretention planter WQ flow rate required for a proprietary treatment system Page | 1 April 2017 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS) AND PHOSPHORUS TREATMENT For CONTECH Engineered Solutions Stormwater Management StormFilter® with PhosphoSorb® media Ecology’s Decision: 1. Based on Contech Engineered Solutions application, Ecology hereby issues the following use level designation for the Stormwater Management StormFilter® using PhosphoSorb® media cartridges:  General Use Level Designation (GULD) for Basic Treatment (total suspended solids) and for Phosphorus (total phosphorus) treatment. o Sized at a hydraulic loading rate of no greater than 1.67 gallon per minute (gpm) per square foot (sq ft.) of media surface, per Table 1. o Using Contech’s PhosphoSorb media. Specifications for the media shall match the specifications provided by the manufacturer and approved by Ecology. Table 1. StormFilter cartridge design flow rates for 18-inch diameter cartridges with PhosphoSorb media operating at 1.67 gpm/sq ft. Effective cartridge height (in) Cartridge flow rate (gpm/cartridge) 12 8.35 18 12.53 27 18.79 0.0419 cfs Page | 2 2. Ecology approves StormFilter systems containing PhosphoSorb media for treatment at the cartridge flow rate shown in Table 1, and sized based on the water quality design flow rate for an off-line system. Contech designs their StormFilter systems to maintain treatment of the water quality design flow while routing excess flows around the treatment chamber during periods of peak bypass. Calculate the water quality design flow rates using the following procedures:  Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model.  Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual.  Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 3. The GULD designation has no expiration date but it may be amended or revoked by Ecology and is subject to the conditions specified below. Ecology’s Conditions of Use: StormFilter systems containing PhosphoSorb media shall comply with these conditions: 1. Design, assemble, install, operate, and maintain StormFilter systems containing PhosphoSorb media in accordance with applicable Contech Engineered Solutions manuals, documents, and the Ecology Decision. 2. Use sediment loading capacity, in conjunction with the water quality design flow rate, to determine the target maintenance interval. 3. Owners shall install StormFilter systems in such a manner that bypass flows exceeding the water quality treatment rate or flows through the system will not re-suspend captured sediments. 4. Pretreatment of TSS and oil and grease may be necessary, and designers shall provide pre-treatment in accordance with the most current versions of the CONTECH Product Design Manual or the applicable Ecology Stormwater Manual. Design pre-treatment using the performance criteria and pretreatment practices provided in the Stormwater Management Manual for Western Washington (SWMMWW), the Stormwater Management Manual for Eastern Washington (SWMMEW), or on Ecology’s “Evaluation of Emerging Stormwater Treatment Technologies” website. 5. Maintenance: The required maintenance interval for stormwater treatment devices is often dependent upon the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a “one size fits all” maintenance cycle for a particular model/size of manufactured filter treatment device.  Typically, CONTECH designs StormFilter systems for a target filter media replacement interval of 12 months. Maintenance includes removing accumulated Page | 3 sediment from the vault, and replacing spent cartridges with recharged cartridges.  Indications of the need for maintenance include the effluent flow decreasing to below the design flow rate, as indicated by the scumline above the shoulder of the cartridge.  Owners/operators must inspect StormFilter with PhosphoSorb media for a minimum of twelve months from the start of post-construction operation to determine site-specific maintenance schedules and requirements. You must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to SWMMEW, the wet season in eastern Washington is October 1 to June 30). After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections.  Conduct inspections by qualified personnel, follow manufacturer’s guidelines, and use methods capable of determining either a decrease in treated effluent flowrate and/or a decrease in pollutant removal ability.  When inspections are performed, the following findings typically serve as maintenance triggers:  Accumulated vault sediment depths exceed an average of 2 inches, or  Accumulated sediment depths on the tops of the cartridges exceed an average of 0.5 inches, or  Standing water remains in the vault between rain events, or  Bypass during storms smaller than the design storm.  Note: If excessive floatables (trash and debris) are present, perform a minor maintenance consisting of gross solids removal, not cartridge replacement. 6. Discharges from the StormFilter systems containing PhosphoSorb media shall not cause or contribute to water quality standards violations in receiving waters. Applicant: CONTECH Engineered Solutions Applicant’s Address: 11835 NE Glenn Widing Dr. Portland, OR 97220 Page | 4 Application Documents:  The Stormwater Management StormFilter, PhosphoSorb at a Specific Flow Rate of 1.67 gpm/ft2, Conditional Use Level Designation Application. August 2012.  Quality Assurance Project Plan The Stormwater Management StormFilter® PhosphoSorb® at a Specific Flow Rate of 1.67 gpm/ft2 Performance Evaluation. August 2012.  The Stormwater Management StormFilter® PhosphoSorb® at a Specific Flow Rate of 1.67 gpm/ft2, General Use Level Designation, Technical Evaluation Report. October 2015. Applicant’s Use Level Request:  General use level designation as a basic (TSS) and phosphorus (total phosphorus) treatment device in accordance with Table 2 of Ecology’s 2011 Technical Guidance Manual for Evaluating Emerging Stormwater Treatment Technologies Technology Assessment Protocol – Ecology (TAPE). Applicant’s Performance Claims: Based on results from laboratory and field-testing, the applicant claims:  The Stormwater Management StormFilter® with PhosphoSorb® media operating at 1.67 gpm/ft2 is able to remove 80% of Total Suspended Solids (TSS) for influent concentrations greater than 100 mg/L, is able to remove greater than 80% TSS for influent concentrations greater than 200 mg/L, and achieve a 20 mg/L effluent for influent concentrations less than 100 mg/L.  The StormFilter with PhosphoSorb media is able to remove 50% or greater total phosphorus for influent concentrations between 0.1 to 0.5 mg/L. Recommendations: Ecology finds that:  CONTECH Engineered Solutions has shown Ecology, through laboratory and field testing, that the Stormwater Management StormFilter® with PhosphoSorb® media is capable of attaining Ecology’s Basic and Total Phosphorus treatment goals. Findings of Fact: Laboratory testing  A Phosphosorb StormFilter cartridge test unit, operating at 28 L/min (equivalent to 1.0 gpm/ sq. ft.), and subject to SSC with a silt loam texture (25% sand, 65% silt, and 10% clay by mass) originating from SCS 106 provides a mean SSC removal efficiency of 88%;  A Phosphosorb StormFilter cartridge test unit, operating at 56 L/min (equivalent to 2.0 gpm/sq. ft.), and subject to SSC with a silt loam texture (25% sand, 65% silt, and 10% clay by mass) originating from SCS 106 provides a mean turbidity reduction of 82%; Page | 5  Laboratory testing of PhosphoSorb media in a Horizontal Flow Column (HFC; a 1/24th scale of a full cartridge) resulted in 50 percent dissolved phosphorus removal for the first 1,000 bed volumes. Granular activated carbon (GAC) tested under the same conditions resulted in 30 percent removal of dissolved phosphorus. Field testing  Contech conducted monitoring of a StormFilter® with PhosphoSorb® media at a site along Lolo Pass Road in Zigzag, Oregon between February 2012 and February 2015. The manufacturer collected flow-weighted influent and effluent composite samples during 17 separate storm events. The system treated approximately 96 percent of the flows recorded during the monitoring period. The applicant sized the system at 1.67 gpm/sq. ft. o Influent TSS concentrations for qualifying sampled storm events ranged from 40 to 780 mg/L. For influent concentrations less than 100 mg/L (n=2) the effluent concentration was less than 10 mg/L. For influent concentrations greater than 100 mg/L the bootstrap estimate of the lower 95 percent confidence limit (LCL95) of the mean TSS reduction was 85%. o Total phosphorus removal for 16 events with influent TP concentrations in the range of 0.1 to 0.5 mg/L averaged 75 percent. A bootstrap estimate of the lower 95 percent confidence limit (LCL95) of the mean total phosphorus reduction was 67 percent. Other StormFilter system with PhosphoSorb media items the Company should address: 1. Conduct testing to obtain information about maintenance requirements in order to come up with a maintenance cycle. 2. Conduct loading tests on the filter to determine maximum treatment life of the system. Technology Description: Download at: http://www.conteches.com/Products/Stormwater- Management/Treatment/Stormwater-Management-StormFilter®.aspx Contact Information: Applicant: Jeremiah Lehman Contech Engineered Solutions 11815 NE Glenn Widing Drive Portland, OR, 97220 503-258-3136 jlehman@conteches.com Applicant website: www.conteches.com Page | 6 Ecology web link: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/index.html Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Revision History Date Revision December 2012 Original use-level-designation document: CULD for basic and phosphorus treatment. January 2013 Revised document to match standard formatting August 2014 Revised TER and expiration dates November 2015 Approved GULD designation for Basic and Phosphorus treatment November 2016 Revised Contech contact information April 2017 Revised sizing language to note sizing based on Off-line calculations MJB North Roadway –MJB Properties Appendix 5 Appendix 5 Conveyance Calculations Drawing Title Date Drawing Reference Drawn/Ck'd By Scale ASI/RFI/CSK Number 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com Project Title Client MJB NORTH MJB PROPERTIES STORMWATER PLAN 1"=150' 5/12/2023 KNM FO R R E F E R E N C E O N L Y Drawing Title Date Drawing Reference Drawn/Ck'd By Scale ASI/RFI/CSK Number 1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com Project Title Client MJB NORTH MJB PROPERTIES STORMWATER PLAN 1"=150' 5/12/2023 KNM FO R R E F E R E N C E O N L Y 100-year runoff= 12.7 CFS Existing 100-year runoff= 6.3 CFS 100-year runoff= 14.7 CFS DRAINAGE BASIN EXHIBIT 303,872.2 sf Label Solve For Friction Method Roughness Coefficient south 12" outfall Full Flow Capacity Manning Formula 0.024 middle 8" outfall Full Flow Capacity Manning Formula 0.024 middle 18" outfall Full Flow Capacity Manning Formula 0.013 north 36" outfall Full Flow Capacity Manning Formula 0.013 Channel Slope (ft/ft) Normal Depth (ft) Diameter (ft) Discharge (ft³/s) 0.01000 1.00 1.00 1.93 0.01000 0.67 0.67 0.66 0.01000 1.50 1.50 10.50 0.01000 3.00 3.00 66.69 Flow Area (ft²) Wetted Perimeter (ft) Hydraulic Radius (ft) Top Width (ft) 0.79 3.14 0.25 0.00 0.35 2.10 0.17 0.00 1.77 4.71 0.38 0.00 7.07 9.42 0.75 0.00 Critical Depth (ft) Percent Full (%) Critical Slope (ft/ft) Velocity (ft/s) 0.59 100.0 0.02305 2.46 0.38 100.0 0.02567 1.88 1.25 100.0 0.00977 5.94 2.61 100.0 0.00912 9.44 Circular Pipe (outfall conveyance.fm8) Report 4/19/2023 2:44:41 PM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of1Page total capacity of existing outfalls = 79.8 CFS Velocity Head (ft) Specific Energy (ft) Froude Number Maximum Discharge (ft³/s) 0.09 1.09 0.00 2.08 0.06 0.73 0.00 0.71 0.55 2.05 0.00 11.30 1.38 4.38 0.00 71.74 Discharge Full (ft³/s) Slope Full (ft/ft) Flow Type Notes 1.93 0.01000 SubCritical 0.66 0.01000 SubCritical 10.50 0.01000 SubCritical 66.69 0.01000 SubCritical Messages Circular Pipe (outfall conveyance.fm8) Report 4/19/2023 2:44:41 PM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of2Page CX.21 CX.22 CX.10 CX.11 CX.12 CX.13 CX . 1 7 CX . 1 5 CX.14 CX . 1 8 CX . 1 6 C X . 1 9 1601 5th Avenue, Suite 1600Seattle, WA 98101 206.622.5822 www.kpff.com 04/27/2022 17-C 16-C 15-C 14-C 21-C 21-D 10-C 9-C 8-C 7-C 6-C 4-C 3 21 4-A/B6-A/B7-A/B 8-A/B9-A/B 10-A/B 11-A/B 12-A/B 14-A/B 15-A/B 16-A/B17-A/B 19- A/B 20- A/B DRAINAGE BASIN EXHIBIT 18-A 18-B 21-A/B 11-C 22-A/B 13-C KPFF Consulting Engineers MJB Anacortes KPFF Consulting Engineers July 2023 Drainage Calculations - Conveyance Check for the 100-year Storm Event ASSUMPTIONS AND CONSTANTS ASSUMPTIONS AND CONSTANTS cont. Manning's n =0.014 (per KCSWDM Table 4.2.1 D for Conc. Pipe - Uniform Flow Analysis) 8 -in Pipe Wall Thickness =2.0 in. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) Pr =3.3 in. (for 100-year event per DOE SWMMWW Volume 3, A-5) 12 -in Pipe Wall Thickness =2.0 in. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) ar =2.61 (for 100-year event per COA SWM Table 3.2) 18 -in Pipe Wall Thickness =2.5 in. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) br =0.63 (for 100-year event per COA SWM Table 3.2) 24 -in Pipe Wall Thickness =3.0 in. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) Tc =6.3 minutes (minimum Tc per COA SWM pg. 24) 30 -in Pipe Wall Thickness =4.0 in. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) C impervious =0.90 (per COA Table 3.1 for Pavement and Roofs) Min Cover for Plain Conc. Pipe =1.5 ft. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) C pervious =0.25 (per COA Table 3.1 for Pavement and Roofs) Min Cover for Class IV Conc. Pipe =1.0 ft. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) V min. allow. =3.0 ft/s (for Pipes, per COA SWM pg. SWM-3) Min Cover for Class V Conc. Pipe =0.5 ft. (per WSDOT Hydraulics Manual Table 8-11.2 (English)) V max. allow. =5.0 ft/s (for Bioswales and Ditches with less than 6% longitudinal slope, per KCSWDM pg. 6-40) Project Pavement Thickness =0.875 ft. (per XXXXX) Min. Cover =24 in. (36" for non-pressure rated PVC per COA SWM pg. 46, Storm Drainage General Plan Notes- pg 248) Layout Contributing Flow Calculations (Rational Method) Pipe Capacity Calculations Conveyance Checks Notes Structure Number Impervious Area Pervious Area Area Contributing Q QTotal Inlet Rim Elevation Outlet Rim Elevation Inlet Invert Elevation Outlet Invert Elevation Pipe Diameter Length Slope Velocity, V Pipe Flow Capacity, Q Inlet Cover Outlet Cover Rim to Invert Pipe Type Pipe Capacity Used VFull Check Q Check Inlet Cover Outlet Cover Comments (sf)(sf)(acres)(cfs)(cfs)(inches)(feet)(%)(ft/s)(cfs)(ft)(ft)(ft)(%) 1 7 8 9 16 17 18 19 20 21 22 23 24 27 28 29 30 34 35 36 37 38 39 53 Storm Drainage Area: Basin A draining to Existing Storm Drainage System at N 15th St & 1st Ave W 1st Ave W (100+00 to 200+50) & N 17th St (400+00 to 500+00) 0 SDMH 23 303,872 sf 0 sf 6.98 ac 5.74 cfs 5.74 cfs 24.24 22.68 17.62 14.76 18 in 178.0 ft 1.61%7.00 ft/s 12.38 cfs 4.9 ft 6.2 ft 6.6 ft Plain 46.4%OK OK OK OK SDCB 22B 5,963 sf 0 sf 0.14 ac 0.11 cfs 0.11 cfs 22.32 22.68 19.57 15.59 8 in 22.0 ft 2.10%4.66 ft/s 1.63 cfs 1.9 ft 6.3 ft 2.8 ft DI 6.9%OK OK Check OK SDCB 22A 5,963 sf 0 sf 0.14 ac 0.11 cfs 0.11 cfs 22.31 22.68 19.56 15.59 8 in 22.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 6.3 ft 2.8 ft DI 7.1%OK OK Check OK SDMH 22 0 sf 0 sf 0.00 ac 0.00 cfs 5.97 cfs 22.68 21.89 14.76 12.54 18 in 138.0 ft 1.61%7.00 ft/s 12.38 cfs 6.2 ft 7.6 ft 7.9 ft Plain 48.2%OK OK OK OK SDCB 21D 19,958 sf 2,218 sf 0.51 ac 0.38 cfs 0.38 cfs 22.10 21.89 13.36 13.04 12 in 32.0 ft 1.00%4.21 ft/s 3.31 cfs 7.6 ft 7.7 ft 8.7 ft Plain 11.4%OK OK OK OK SDCB 21C 13,535 sf 1,504 sf 0.35 ac 0.26 cfs 0.26 cfs 22.50 21.89 14.01 13.04 12 in 32.0 ft 1.00%4.21 ft/s 3.31 cfs 7.3 ft 7.7 ft 8.5 ft Plain 7.7%OK OK OK OK SDCB 21B 4,512 sf 0 sf 0.10 ac 0.09 cfs 0.09 cfs 21.56 21.89 18.81 13.37 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.7 ft 2.8 ft DI 5.4%OK OK Check OK SDCB 21A 4,512 sf 0 sf 0.10 ac 0.09 cfs 0.09 cfs 21.56 21.89 18.81 13.37 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.7 ft 2.8 ft DI 5.4%OK OK Check OK SDMH 21 0 sf 0 sf 0.00 ac 0.00 cfs 6.77 cfs 21.89 22.29 12.54 11.62 18 in 57.0 ft 1.61%7.00 ft/s 12.38 cfs 7.6 ft 9.0 ft 9.4 ft Plain 54.7%OK OK OK OK SDCB 20C 0 sf 0 sf 0.00 ac 0.00 cfs 0.00 cfs 15.50 14.97 8.33 7.96 12 in 37.0 ft 1.00%4.21 ft/s 3.31 cfs 6.0 ft 5.8 ft 7.2 ft Plain 0.0%OK OK OK OK SDCB 20B 5,156 sf 0 sf 0.12 ac 0.10 cfs 0.10 cfs 14.54 14.97 11.79 8.29 8 in 22.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 5.8 ft 2.8 ft DI 6.1%OK OK Check OK SDCB 20A 5,156 sf 0 sf 0.12 ac 0.10 cfs 0.10 cfs 14.54 14.97 11.79 8.29 8 in 22.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 5.8 ft 2.8 ft DI 6.1%OK OK Check OK SDMH 20 0 sf 0 sf 0.00 ac 0.00 cfs 0.19 cfs 14.97 15.51 7.96 7.38 12 in 147.0 ft 0.40%2.66 ft/s 2.09 cfs 5.8 ft 7.0 ft 7.0 ft Plain 9.3%Check OK OK OK SDCB 19C 0 sf 0 sf 0.00 ac 0.00 cfs 0.00 cfs 15.80 15.51 7.69 7.38 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 6.9 ft 7.0 ft 8.1 ft Plain 0.0%OK OK OK OK SDCB 19B 4,407 sf 0 sf 0.10 ac 0.08 cfs 0.08 cfs 15.16 15.51 12.40 7.71 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.0 ft 2.8 ft DI 5.2%OK OK Check OK SDCB 19A 4,407 sf 0 sf 0.10 ac 0.08 cfs 0.08 cfs 15.16 15.51 12.40 7.71 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.0 ft 2.8 ft DI 5.2%OK OK Check OK SDMH 19 0 sf 0 sf 0.00 ac 0.00 cfs 0.36 cfs 15.51 16.50 7.38 6.76 12 in 154.0 ft 0.40%2.66 ft/s 2.09 cfs 7.0 ft 8.6 ft 8.1 ft Plain 17.3%Check OK OK OK SDCB 18B 3,078 sf 0 sf 0.07 ac 0.06 cfs 0.06 cfs 27.80 27.25 23.00 20.97 8 in 40.0 ft 5.06%7.23 ft/s 2.52 cfs 4.0 ft 5.4 ft 4.8 ft Plain 2.3%OK OK OK OK SDCB 18A 2,536 sf 0 sf 0.06 ac 0.05 cfs 0.05 cfs 27.49 27.25 22.49 20.97 8 in 39.0 ft 3.92%6.36 ft/s 2.22 cfs 4.2 ft 5.4 ft 5.0 ft Plain 2.2%OK OK OK OK SDMH 18 0 sf 0 sf 0.00 ac 0.00 cfs 0.11 cfs 27.25 26.43 18.17 17.60 12 in 114.0 ft 0.50%2.98 ft/s 2.34 cfs 7.9 ft 7.7 ft 9.1 ft Plain 4.5%Check OK OK OK SDCB 17C 30,368 sf 3,374 sf 0.77 ac 0.57 cfs 0.57 cfs 26.50 26.43 17.91 17.60 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 7.4 ft 7.7 ft 8.6 ft Plain 17.3%OK OK OK OK SDCB 17B 4,829 sf 0 sf 0.11 ac 0.09 cfs 0.09 cfs 26.15 26.43 23.40 17.93 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.7 ft 2.8 ft DI 5.7%OK OK Check OK SDCB 17A 4,829 sf 0 sf 0.11 ac 0.09 cfs 0.09 cfs 26.15 26.43 23.40 17.93 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.7 ft 2.8 ft DI 5.7%OK OK Check OK SDMH 17 0 sf 0 sf 0.00 ac 0.00 cfs 0.86 cfs 26.43 25.62 17.60 17.04 12 in 112.0 ft 0.50%2.98 ft/s 2.34 cfs 7.7 ft 7.4 ft 8.8 ft Plain 36.9%Check OK OK OK SDCB 16C 25,492 sf 2,832 sf 0.65 ac 0.48 cfs 0.48 cfs 26.00 25.62 17.35 17.04 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 7.5 ft 7.4 ft 8.7 ft Plain 14.6%OK OK OK OK SDCB 16B 3,338 sf 0 sf 0.08 ac 0.06 cfs 0.06 cfs 25.34 25.62 22.59 17.37 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.4 ft 2.8 ft DI 4.0%OK OK Check OK SDCB 16A 3,338 sf 0 sf 0.08 ac 0.06 cfs 0.06 cfs 25.34 25.62 22.59 17.37 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.4 ft 2.8 ft DI 4.0%OK OK Check OK SDMH 16 0 sf 0 sf 0.00 ac 0.00 cfs 1.47 cfs 25.62 24.73 17.04 16.42 12 in 123.0 ft 0.50%2.98 ft/s 2.34 cfs 7.4 ft 7.1 ft 8.6 ft Plain 62.9%Check OK OK OK SDCB 15C 33,033 sf 3,681 sf 0.84 ac 0.62 cfs 0.62 cfs 25.10 24.73 16.73 16.42 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 7.2 ft 7.1 ft 8.4 ft Plain 18.9%OK OK OK OK SDCB 15B 3,702 sf 0 sf 0.08 ac 0.07 cfs 0.07 cfs 24.46 24.73 21.70 16.75 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.1 ft 2.8 ft DI 4.4%OK OK Check OK SDCB 15A 3,702 sf 0 sf 0.08 ac 0.07 cfs 0.07 cfs 24.46 24.73 21.70 16.75 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.1 ft 2.8 ft DI 4.4%OK OK Check OK SDMH 15 0 sf 0 sf 0.00 ac 0.00 cfs 2.23 cfs 24.73 23.89 16.42 15.73 12 in 116.0 ft 0.60%3.26 ft/s 2.56 cfs 7.1 ft 7.0 ft 8.3 ft Plain 87.2%OK OK OK OK SDMH 14C 32,672 sf 3,630 sf 0.83 ac 0.62 cfs 0.62 cfs 24.10 23.89 16.04 15.73 12 in 32.0 ft 1.00%4.21 ft/s 3.31 cfs 6.9 ft 7.0 ft 8.1 ft Plain 18.7%OK OK OK OK SDMH 14B 6,967 sf 0 sf 0.16 ac 0.13 cfs 0.13 cfs 23.62 23.89 20.87 16.06 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.0 ft 2.8 ft DI 8.3%OK OK Check OK SDMH 14A 6,967 sf 0 sf 0.16 ac 0.13 cfs 0.13 cfs 23.62 23.89 20.87 16.06 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.0 ft 2.8 ft DI 8.3%OK OK Check OK SDMH 14 0 sf 0 sf 0.00 ac 0.00 cfs 3.12 cfs 23.89 23.06 15.23 14.76 18 in 116.0 ft 0.40%3.49 ft/s 6.17 cfs 7.0 ft 6.6 ft 8.7 ft Plain 50.5%OK OK OK OK SDCB 13C 34,837 sf 3,871 sf 0.89 ac 0.66 cfs 0.66 cfs 20.70 23.06 14.98 12.79 12 in 55.0 ft 2.00%5.96 ft/s 4.68 cfs 4.6 ft 9.1 ft 5.7 ft Plain 14.1%OK OK OK OK SDMH 13 0 sf 0 sf 0.00 ac 0.00 cfs 3.77 cfs 23.06 22.70 12.29 11.74 18 in 50.0 ft 1.10%5.79 ft/s 10.23 cfs 9.1 ft 9.3 ft 10.8 ft Plain 36.9%OK OK OK OK SDCB 12-1B 5,217 sf 0 sf 0.12 ac 0.10 cfs 0.10 cfs 22.39 22.70 19.64 12.57 8 in 13.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 9.3 ft 2.8 ft DI 6.2%OK OK Check OK SDCB 12-1A 5,217 sf 0 sf 0.12 ac 0.10 cfs 0.10 cfs 22.39 22.70 19.64 12.57 8 in 13.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 9.3 ft 2.8 ft DI 6.2%OK OK Check OK SDMH 12-1 0 sf 0 sf 0.00 ac 0.00 cfs 3.97 cfs 22.70 22.29 11.74 11.62 18 in 56.0 ft 1.10%5.79 ft/s 10.23 cfs 9.3 ft 9.0 ft 11.0 ft Plain 38.8%OK OK OK OK SDMH 12 0 sf 0 sf 0.00 ac 0.00 cfs 10.74 cfs 22.29 21.38 11.12 10.61 24 in 127.0 ft 0.40%4.23 ft/s 13.29 cfs 8.9 ft 8.5 ft 11.2 ft Plain 80.8%OK OK OK OK SDCB 11C 18,024 sf 2,003 sf 0.46 ac 0.34 cfs 0.34 cfs 21.50 21.38 11.92 11.61 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 8.4 ft 8.6 ft 9.6 ft Plain 10.3%OK OK OK OK SDCB 11B 6,380 sf 0 sf 0.15 ac 0.12 cfs 0.12 cfs 21.11 21.38 18.36 11.94 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 8.6 ft 2.8 ft DI 7.6%OK OK Check OK SDCB 11A 6,380 sf 0 sf 0.15 ac 0.12 cfs 0.12 cfs 21.11 21.38 18.36 11.94 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 8.6 ft 2.8 ft DI 7.6%OK OK Check OK SDMH 11 0 sf 0 sf 0.00 ac 0.00 cfs 11.32 cfs 21.38 20.47 10.61 10.11 24 in 127.0 ft 0.40%4.23 ft/s 13.29 cfs 8.5 ft 8.1 ft 10.8 ft Plain 85.2%OK OK OK OK SDCB 10C 45,755 sf 5,084 sf 1.17 ac 0.86 cfs 0.86 cfs 20.50 20.47 11.42 11.11 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 7.9 ft 8.2 ft 9.1 ft Plain 26.1%OK OK OK OK SDCB 10B 3,785 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 20.19 20.47 17.44 11.44 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 8.2 ft 2.8 ft DI 4.5%OK OK Check OK SDCB 10A 3,785 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 20.19 20.47 17.44 11.44 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 8.2 ft 2.8 ft DI 4.5%OK OK Check OK SDMH 10 0 sf 0 sf 0.00 ac 0.00 cfs 12.33 cfs 20.47 19.55 10.11 9.60 24 in 127.0 ft 0.40%4.23 ft/s 13.29 cfs 8.1 ft 7.7 ft 10.4 ft Plain 92.8%OK OK OK OK SDCB 9C 47,857 sf 5,317 sf 1.22 ac 0.90 cfs 0.90 cfs 19.80 19.55 10.91 10.60 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 7.7 ft 7.8 ft 8.9 ft Plain 27.3%OK OK OK OK SDCB 9B 3,817 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 19.28 19.55 16.53 10.93 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.8 ft 2.8 ft DI 4.5%OK OK Check OK SDCB 9A 3,817 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 19.28 19.55 16.53 10.93 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.8 ft 2.8 ft DI 4.5%OK OK Check OK SDMH 9 0 sf 0 sf 0.00 ac 0.00 cfs 13.38 cfs 19.55 18.64 9.60 8.97 24 in 127.0 ft 0.50%4.73 ft/s 14.85 cfs 7.7 ft 7.4 ft 10.0 ft Plain 90.1%OK OK OK OK SDMH 8C 54,491 sf 6,055 sf 1.39 ac 1.03 cfs 1.03 cfs 19.10 18.64 10.28 9.97 12 in 31.0 ft 1.00%4.21 ft/s 3.31 cfs 7.7 ft 7.5 ft 8.8 ft Plain 31.1%OK OK OK OK SDMH 8B 3,808 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 18.36 18.64 15.61 10.30 8 in 15.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.5 ft 2.8 ft DI 4.5%OK OK Check OK SDMH 8A 3,808 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 18.36 18.64 15.61 10.30 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.5 ft 2.8 ft DI 4.5%OK OK Check OK SDMH 8 0 sf 0 sf 0.00 ac 0.00 cfs 14.55 cfs 18.64 17.72 8.97 8.20 24 in 128.0 ft 0.60%5.18 ft/s 16.27 cfs 7.4 ft 7.3 ft 9.7 ft Plain 89.4%OK OK OK OK SDCB 7C 51,522 sf 5,725 sf 1.31 ac 0.97 cfs 0.97 cfs 18.10 17.72 9.51 9.20 12 in 32.0 ft 1.00%4.21 ft/s 3.31 cfs 7.4 ft 7.4 ft 8.6 ft Plain 29.4%OK OK OK OK SDCB 7B 3,809 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 17.45 17.72 14.70 9.53 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.4 ft 2.8 ft DI 4.5%OK OK Check OK SDCB 7A 3,809 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 17.45 17.72 14.70 9.53 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.4 ft 2.8 ft DI 4.5%OK OK Check OK SDMH 7 0 sf 0 sf 0.00 ac 0.00 cfs 15.67 cfs 17.72 16.80 8.20 7.12 24 in 127.0 ft 0.85%6.16 ft/s 19.37 cfs 7.3 ft 7.4 ft 9.5 ft Plain 80.9%OK OK OK OK SDCB 6C 47,033 sf 5,226 sf 1.20 ac 0.89 cfs 0.89 cfs 11.50 16.80 8.65 8.12 12 in 53.0 ft 1.00%4.21 ft/s 3.31 cfs 1.7 ft 7.5 ft 2.9 ft Class V 26.9%OK OK Check OK SDCB 6B 3,788 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 16.53 16.80 13.78 8.45 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.5 ft 2.8 ft DI 4.5%OK OK Check OK SDCB 6A 3,788 sf 0 sf 0.09 ac 0.07 cfs 0.07 cfs 16.53 16.80 13.78 8.45 8 in 16.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 7.5 ft 2.8 ft DI 4.5%OK OK Check OK SDMH 6 0 sf 0 sf 0.00 ac 0.00 cfs 16.70 cfs 16.80 16.50 7.12 6.76 24 in 42.0 ft 0.85%6.16 ft/s 19.37 cfs 7.4 ft 7.5 ft 9.7 ft Plain 86.2%OK OK OK OK SDMH 5 0 sf 0 sf 0.00 ac 0.00 cfs 17.06 cfs 16.50 13.84 6.76 6.50 30 in 123.0 ft 3.00%13.44 ft/s 65.97 cfs 6.9 ft 4.5 ft 9.7 ft Plain 25.9%OK OK OK OK SDCB 4D 0 sf 0 sf 0.00 ac 0.00 cfs 0.67 cfs 14.27 13.84 8.26 8.00 12 in 37.0 ft 1.00%4.21 ft/s 3.31 cfs 4.8 ft 4.7 ft 6.0 ft 20.2%OK OK OK OK SDCB 4C 35,326 sf 3,925 sf 0.90 ac 0.67 cfs 0.67 cfs 12.01 14.27 8.44 8.26 12 in 17.0 ft 1.00%4.21 ft/s 3.31 cfs 2.4 ft 4.8 ft 3.6 ft Plain 20.2%OK OK OK OK SDCB 4B 8,038 sf 0 sf 0.18 ac 0.15 cfs 0.15 cfs 13.43 13.84 10.68 8.33 8 in 17.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 4.7 ft 2.8 ft DI 9.6%OK OK Check OK SDCB 4A 8,038 sf 0 sf 0.18 ac 0.15 cfs 0.15 cfs 13.43 13.84 10.68 8.33 8 in 18.0 ft 2.00%4.55 ft/s 1.59 cfs 1.9 ft 4.7 ft 2.8 ft DI 9.6%OK OK Check OK SDMH 4 0 sf 0 sf 0.00 ac 0.00 cfs 18.03 cfs 13.84 12.00 6.50 5.82 30 in 193.0 ft 0.35%4.59 ft/s 22.53 cfs 4.5 ft 3.3 ft 7.3 ft Plain 80.0%OK OK OK OK SDMH 3 19,638 sf 2,182 sf 0.50 ac 0.37 cfs 18.41 cfs 12.00 14.00 5.82 5.11 30 in 200.0 ft 0.35%4.59 ft/s 22.53 cfs 3.3 ft 6.1 ft 6.2 ft Plain 81.7%OK OK OK OK SDMH 2 12,951 sf 1,439 sf 0.33 ac 0.24 cfs 18.65 cfs 12.80 15.64 5.11 4.76 30 in 100.0 ft 0.35%4.59 ft/s 22.53 cfs 4.9 ft 8.0 ft 7.7 ft Plain 82.8%OK OK OK OK SDMH 1 15,736 sf 1,748 sf 0.40 ac 0.30 cfs 18.95 cfs 15.64 14.00 4.26 1.90 36 in 169.0 ft 1.40%10.37 ft/s 73.28 cfs #N/A #N/A #N/A #N/A 25.9%OK OK #N/A #N/A Connects to Ex. SD, Info per survey New Alignment_MGS Flood Conveyance and BW Check.xlsm | 100-Year Conveyance 1 of 1 7/20/2023 | 11:25 AM stormwater runoff flow rate from the existing area west of Q/R Avenue and between Q/R Avenue and Barcott Way ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.58 Program License Number: 200410007 Project Simulation Performed on: 07/20/2023 11:46 AM Report Generation Date: 07/20/2023 11:46 AM ————————————————————————————————— Input File Name: MJB Conveyance.fld Project Name: MJB Conveyance Analysis Title: Comments: Area between Barcott Way & Fidalgo Bay ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Full Period of Record Available used for Routing Climatic Region Number: 12 Precipitation Station : 96002805 Puget East 28 in_5min 10/01/1940-10/01/2003 Evaporation Station : 961028 Puget East 28 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : Ecology Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 11.822 11.822 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 11.822 11.822 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 4 ---------- Subbasin : to South 12" outfall ---------- -------Area (Acres) -------- ROADS/FLAT 4.004 ---------------------------------------------- Subbasin Total 4.004 ---------- Subbasin : to middle 8" outfall ---------- -------Area (Acres) -------- ROADS/FLAT 2.720 ---------------------------------------------- Subbasin Total 2.720 ---------- Subbasin : to middle 18" outfall ---------- -------Area (Acres) -------- ROADS/FLAT 2.885 ---------------------------------------------- Subbasin Total 2.885 ---------- Subbasin : to north 36" outfall ---------- -------Area (Acres) -------- ROADS/FLAT 2.213 ---------------------------------------------- Subbasin Total 2.213 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- A/B, Lawn, Flat 1.182 ROADS/FLAT 10.640 ---------------------------------------------- Subbasin Total 11.822 ***********Compliance Point Results ************* Scenario Predeveloped Compliance Link: New Copy Lnk1 Scenario Postdeveloped Compliance Subbasin: Subbasin 1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 3.563 2-Year 3.207 5-Year 4.770 5-Year 4.293 10-Year 5.943 10-Year 5.349 25-Year 7.470 25-Year 6.723 50-Year 8.467 50-Year 7.620 100-Year 9.731 100-Year 8.758 200-Year ** 200-Year ** 500-Year ** 500-Year ** ** Record too Short to Compute Peak Discharge for These Recurrence Intervals stormwater runoff flow rate from the area between Barcott Way and Fidalgo bay The entire area between Barcott Way & Fidalgo Bay was assumed to be 90% impervious for calculations. This matches land use code requiring 10% landscape.