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HomeMy WebLinkAboutRS_SWPPP_210810Solera – DevCo, LLC Page 1 Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP) for Solera Prepared for: Washington State Department of Ecology 300 Desmond Drive Southeast Lacey, Washington 98503 Permittee / Owner Developer Operator / Contractor Solera, LLC 10900 NE 8th Street, Suite 1200 Bellevue, WA 98004 Solera, LLC 10900 NE 8th Street, Suite 1200 Bellevue, WA 98004 Heartland Construction, LLC 10900 NE 8th Street, Suite 1200 Bellevue, WA 98004 Project Site Location: 2842 NE Sunset Boulevard, Renton, WA 98056 Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number TBD TBD TBD SWPPP Prepared By Name Organization Contact Phone Number Michelle Freeman, PE KPFF 206-622-5822 SWPPP Preparation Date August 2021 Project Construction Dates Activity / Phase Start Date End Date Construction Start August 2021 March 2022 Solera – DevCo, LLC Page 2 Table of Contents List of Acronyms and Abbreviations ............................................................................................................. 4 Project Information (1.0) .............................................................................................................................. 5 Existing Conditions (1.1) ........................................................................................................................... 5 Proposed Construction Activities (1.2) ..................................................................................................... 6 Construction Stormwater Best Management Practices (BMPs) (2.0)........................................................... 8 The 13 Elements (2.1) ............................................................................................................................... 8 Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1) ........................................................... 8 Element 2: Establish Construction Access (2.1.2) ................................................................................. 9 Element 3: Control Flow Rates (2.1.3) ................................................................................................ 10 Element 4: Install Sediment Controls (2.1.4) ...................................................................................... 11 Element 5: Stabilize Soils (2.1.5) ......................................................................................................... 12 Element 6: Protect Slopes (2.1.6)........................................................................................................ 13 Element 7: Protect Drain Inlets (2.1.7) ............................................................................................... 14 Element 8: Stabilize Channels and Outlets (2.1.8) .............................................................................. 15 Element 9: Control Pollutants (2.1.9) ................................................................................................. 16 Element 10: Control Dewatering (2.1.10) ........................................................................................... 19 Element 11: Maintain BMPs (2.1.11) .................................................................................................. 20 Element 12: Manage the Project (2.1.12) ........................................................................................... 21 Element 13: Protect Low Impact Development (LID) BMPs (2.1.13) .................................................. 24 Pollution Prevention Team (3.0) ................................................................................................................. 24 Monitoring and Sampling Requirements (4.0) ........................................................................................... 25 Site Inspection (4.1) ................................................................................................................................ 25 Stormwater Quality Sampling (4.2) ........................................................................................................ 26 Turbidity Sampling (4.2.1) ................................................................................................................... 26 pH Sampling (4.2.2) ............................................................................................................................. 28 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies (5.0) ........................................ 29 303(d) Listed Waterbodies (5.1) ............................................................................................................. 29 N/A .......................................................................................................................................................... 29 TMDL Waterbodies (5.2) ......................................................................................................................... 29 Reporting and Record Keeping (6.0) ........................................................................................................... 30 Record Keeping (6.1) ............................................................................................................................... 30 Solera – DevCo, LLC Page 3 Site Log Book (6.1.1) ........................................................................................................................... 30 Records Retention (6.1.2) ................................................................................................................... 30 Updating the SWPPP (6.1.3) ............................................................................................................... 30 Reporting (6.2) ........................................................................................................................................ 31 Discharge Monitoring Reports (6.2.1) ................................................................................................. 31 Notification of Noncompliance (6.2.2)................................................................................................ 31 Appendix/Glossary .............................................................................................................................. 33 List of Tables Table 1 - West of the Cascade Mountains Crest ......................................................................................... 12 Table 2 – Pollutants ..................................................................................................................................... 16 Table 3 – pH-Modifying Sources ................................................................................................................. 17 Table 4 – Dewatering BMPs ........................................................................................................................ 19 Table 5 – Management ............................................................................................................................... 21 Table 6 – BMP Implementation Schedule ................................................................................................... 22 Table 7 – Team Information ........................................................................................................................ 24 Table 8 – Turbidity Sampling Method ......................................................................................................... 26 Table 9 – pH Sampling Method ................................................................................................................... 28 List of Appendices A. Site Plan 1. TESC Plans 2. TESC Detail B. BMP Detail C. Correspondence D. Site Inspection Form E. Construction Stormwater General Permit (CSWGP) F. 303(d) List Waterbodies / TMDL Waterbodies Information G. Contaminated Site Information H. Engineering Calculations 1. Sediment Pond Sizing Solera – DevCo, LLC Page 4 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 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 Solera – DevCo, LLC Page 5 Project Information (1.0) Project/Site Name: Solera Street/Location: 2842 Northeast Sunset Boulevard City: Renton State: WA Zip code: 98056 Subdivision: N/A Receiving waterbody: Lake Washington Existing Conditions (1.1) Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage: 11.78 Acres Disturbed acreage: 11.78 Acres Existing structures: Three various commercial retail and restaurant structures and one banking structure. Landscape topography: The existing site substantially developed and located within two drainage basins. The site generally slopes 2-5% to the southwest or 2-5% to the north. There is approximately 20 feet of vertical elevation change within the project limits. Drainage patterns: Stormwater runoff from the surface parking generally sheet flows towards existing conveyance systems in Northeast 10th Street, Northeast 12th Street, and Harrington Place. Existing Vegetation: The existing site substantially developed and consists of minimal vegetation, planter strips, and trees through the surface parking lot. The southwest corner consists of underbrush and gravel. Critical Areas: The project was preliminary mapped for isolated sensitive slopes up to approximately 25% per RMC 4-3-050G.2.5.a. These isolated areas evaluated by the project geotechnical engineer and determined to be the result of previous site construction, rather than a naturally occurring slope. List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: N/a Solera – DevCo, LLC Page 6 Proposed Construction Activities (1.2) Description of site development: The existing commertial retail area was previously occupied by a dry cleaner. Detecablable concentrations of Tetrachloroethene (PCE) have been detected from the surface down to the groundwater. The project geologist, TRC Environmental Corporation (TRC), has prepared a Soil Management Plan (SMP) dated June 11, 2021 for soil remediation work. This scope of work is permitted under the City of Renton Grading Permit B21-001703. The proposed on-site conditions will include two large multistory mixed-use buildings for Block A and B, driveway access, grading, utilities, stormwater mitigation facilities, temporary grading on Block C and D, frontage improvements, right-of-way realignment and dedication of Jefferson Avenue Nortwest, and realignment and expansion of Northeast 11th Street. This scope of work will be permitted under the City of Renton Civil Construction Permit C21-001020. Description of construction activities: Construction activities include removal of the contaminated soil and TESC installation per Permit B21-001703. Construction activities for the entire site per Permit C21-001020 will consist of site preparation, TESC installation, grade and fill, storm drainage facilities, flow control BMPs, water quality facilties, and asphalt and concrete paving. Construction stormwater will be detained onsite prior to discharge offsite; see the Solera technical information report (TIR) and TESC plan sheets (C3.00-C3.10) for TESC design and details. Description of site drainage including flow from and onto adjacent properties. Must be consistent with Site Map in Appendix A: Upon project completion, onsite roof runoff from Mixed Use Building B will drain to the underground infiltration facility in the southern portion of the site to the maximum extent feasible. Roof runoff that is not able to be infiltrated will be sent to the storm system in NE 10th Street. Roof runoff from Mixed Use Building A will be sent to three infiltration facilities surrounding Building A. Roof runoff that is not able to be infiltrated will be sent to the storm system in Kirkland Ave NE and Jefferson Ave NE. All ROW runoff will be routed to bioretention planters with any overflow and public street runoff routed to a series of catch basins located within the public road boundaries, and shall be conveyed to a proposed 12-inch storm conveyance pipe outfalling in the Northeast 10th Street stormwater system. Any onsite and ROW surface water not captured due to infeasiblity is considered bypass and will ultimately outfall to existing systems surrounding the site. Solera – DevCo, LLC Page 7 Description of final stabilization (example: extent of revegetation, paving, landscaping): Block A and B will predominately consist of building structures, parking lots, asphalt roadway, and concrete sidewalks. Available site will consist of bioretention and landscaped areas to meet open space requirements. Block C and D will be temporary hydroseeded. Contaminated Site Information: Proposed activities regarding contaminated soils or groundwater (example: on-site treatment system, authorized sanitary sewer discharge): Detecablable low concentrations of PCE have been detected from the surface down to the groundwater. The SMP, provides protocols for proper management of removal within the construction excavation at a depth of 17 feet below grade, transportation, and disposal of the PCE soils. Refer to Appendix G for the SMP. The PCE concentrations are low enough that soil has been deemed as non-dangerous per the SMP. Solera – DevCo, LLC Page 8 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 13 Elements (2.1) Alternatives for all listed BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMP(s) listed below are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in this document. To avoid potential erosion and sediment control issues that may cause a violation(s) of the Kitsap County and Ecology requirements, the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1) To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction shall be clearly marked before and during land-disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the field and on the plans. The BMPs relevant to marking and clearing limits that shall be applied for this project include: List and describe BMPs: High visibility fence (C103) / metal fence, tree protection fence High-visibility metal fencing shall be placed around the perimeter of the site, abutting ROW limits and easements to prevent intentional or unintentional access. High visibility plastic fence shall be places at locations indicating steep slope conditions for staff and public safety. A secure gate shall be located at the construction entrances to restrict acess to construction areas. Alternate BMPs for marking the clearing limits are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in this document. To avoid potential erosion and sediment control issues that may cause a violation(s) of the King County and Ecology requirements, the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. Installation Schedules: Installation prior to construction. Inspection and Maintenance plan: Construction fencing shall be inspected daily to ensure it is in good condition and in correct location. Responsible Staff: CESCL Solera – DevCo, LLC Page 9 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 wheel washing, street sweeping, and street cleaning shall be employed if necessary to prevent sediment from entering state waters. All wash wastewater shall be controlled on site. The specific BMPs related to establishing construction access that shall be used on this project include: List and describe BMPs: Stabilized Construction Entrance (C105), Wheel Wash (C106) The stabilized construction accesses shall be installed at NE 10th Street and Harrington Place NE. The entrance shall have a minimum length of 100 feet and width of 15 feet. Installation Schedules: Installation prior to construction. Inspection and Maintenance plan: Construction access elements shall be inspected daily to ensure it is in good condition and effectively preventing sediment from being tracked into the roadway. Responsible Staff: CESCL Solera – DevCo, LLC Page 10 Element 3: Control Flow Rates (2.1.3) Will you construct stormwater retention and/or detention facilities? A temporary sediment pond will be graded into the southeast corner of block C to receive stormwater runoff from the development of block A and B. Interceptor swales and rock checkdams will route all construction stormwater to the pond to hold the water until it is released into existing storm drainage systems surrounding the site. Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retention, porous pavement) to control flow during construction? Bioretention planters will be utilized in the later stages of construction as well as in the permanent conditions. List and describe BMPs: Check Dams (C207), Temporary Interceptor Swale/Dikes (C200), Wattles (C235) Installation Schedules: All on-site construction runoff will be routed through temporary culverts and swales before being released into the sediment pond where it will then be pumped into the existing systems surrounding the site. The sediment pond will hold stormwater until the onsite stormwater conveyance system is complete. Wattles and check dams shall be installed as construction progresses, indicated on the construction T.E.S.C. plans. The pond was designed per the City of Renton Surface Water Design Manual. The sediment pond stormwater will be tested prior to release. Inspection and Maintenance plan: Check dams and wattles shall be inspected daily to ensure they are in good condition and effectively reducing sediment from leaving the site. The sediment pond and riser system shall be inspected daily, and consistently during storm events, to ensure pond overflow is mitigated. Responsible Staff: CESCL The project site is located west of the Cascade Mountain Crest. As such, the project must comply with Core Requirement 3 (Ecology 2019). In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements (e.g. discharge to combined sewer systems). Solera – DevCo, LLC Page 11 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 and entering the existing stormwater conveyance surrounding the site or sheet flowing as bypass runoff. The specific BMPs to be used for controlling sediment on this project include: List and describe BMPs: Silt Fence (BMP C233), Dust Control (C140), Storm Drain Inlet Protection (BMP C220) Silt fencing shall be installed around the limits of disturbance prior to grading. Storm drain inlet protection shall be installed along onsite private roads in all constructed catch basins during construction to prevent runoff from the construction site from entering the proposed stormwater system prior to future completion treatment as well as any nearby catch basins that could receive construction runoff from the site. Installation Schedules: Installation prior to construction. Inspection and Maintenance plan: Sediment control elements shall be inspected daily to ensure they are in good condition and effectively preventing sediment from leaving the site. Responsible Staff: CESCL In addition, sediment will be removed from paved areas in and adjacent to construction work areas manually or using mechanical sweepers, as needed, to minimize tracking of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. Solera – DevCo, LLC Page 12 Element 5: Stabilize Soils (2.1.5) Table 1 - 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. Exposed and unworked soils shall be stabilized with eh application of effective BMPs to prevent erosion throughout the life of the project. Anticipated project dates: Start date: August 2021 End date: March 2022 Will you construct during the wet season? Yes No List and describe BMPs: Plastic Covering (BMP C123), Surface Roughening (BMP C130), Dust Control (BMP C140), Nets and Blankets (BMP C122) Installation Schedules: Soil stabilizing elements shall be installed as soon as practical following the completion of mass grading and fine grading, and shall be maintained and adjusted as needed. Inspection and Maintenance plan: Soil stabilizing elements shall be inspected daily to ensure they are in good condition. Responsible Staff: CESCL In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. Solera – DevCo, LLC Page 13 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 while aligning with finished site topography. The following specific BMPs shall be used to protect slopes for this project: List and describe BMPs: Interceptor Dike and Swale (BMP C200). Check Dams (C207). Installation Schedules: Slope protection elements shall be installed as practical before and after mass grading and shall be maintained and adjusted as needed. Inspection and Maintenance plan: Slope protection elements shall be inspected daily to ensure they are in good condition and effectively preventing slope erosion. Responsible Staff: CESCL Temporary seeding will be implemented along any disturbed areas of the site prior to construction to insure stabilization of the soil. Permanent seeding will be implemented at the end of construction along the same disturbed site areas. Rock check dams will be used along the swale to reduce the runoff flow going to the temporary sediment pond in the southeast corner of block C. Interceptor swales will be used where runoff from disturbed slopes must be conveyed to the temporary sediment pond. Interceptors will reduce the velocity of the runoff flowing across the site. Solera – DevCo, LLC Page 14 Element 7: Protect Drain Inlets (2.1.7) List and describe BMPs: Storm Drain Inlet Protection (BMP C220) All storm drian inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. Inlet protection devices shall be cleaned (or removed and replaced) when sediment has filled the device by one-third (1/3) or as specified by the manufacturer. Contractor shall provide protection for inlets and catch basins onsite, and including elements within 500 feet downstream of the project site. Inlets shall be inspected weekly at a minimum and daily during storm events. Installation Schedules: Storm drain inlet protection shall be installed at the beginning of construction and will be maintained and adjusted as needed. Inspection and Maintenance plan: Storm drain inlet protection shall be inspected daily to ensure it is in good condition and cleaned or replaced as needed. Responsible Staff: CESCL Solera – DevCo, LLC Page 15 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. List and describe BMPs: Nets and Blankets (BMP C122) See Element 3 for information concerning the sediment pond. Stormwater from the project site shall enter the temporary sediment pond and continue to the surrounding stormwater system. Installation Schedules: See Element 3 for sediment pond installation schedule. Accompanying stabilizing BMPs shall be installed in conjunction with Element 3. Inspection and Maintenance plan: See Element 3 for temporary sediment pond installation schedule. Accompanying stabilizing BMPs shall be inspected and maintained in conjunction with Element 3. Responsible Staff: CESCL The project site is located west of the Cascade Mountain Crest. As such, all temporary on-site conveyance channels shall be designed, constructed, and stabilized to prevent erosion from the expected peak 10 minute velocity of flow from a Type 1A, 10-year, 24-hour recurrence interval storm for the developed condition. Alternatively, the 10-year, 1-hour peak flow rate indicated by an approved continuous runoff simulation model, increased by a factor of 1.6, shall be used. Stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent streambanks, slopes, and downstream reaches shall be provided at the outlets of all conveyance systems. Solera – DevCo, LLC Page 16 Element 9: Control Pollutants (2.1.9) The following pollutants are anticipated to be present on-site: Table 2 – Pollutants Pollutant (and source, if applicable) Diesel fuel – heavy equipment onsite Hydraulic oil – heavy equipment onsite General demolition debris Concrete and concrete slurry – concrete trucks onsite All pollutants, including waste materials and demolition debris, that occur onsite shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good housekeeping and preventative measures shall be taken to ensure that the site will be kept clean, well organized, and free of debris. If required, BMPs to be implemented to control specific sources of pollution are discussed below. List and describe BMPs: Dust Control (BMP C140), Concrete Handling (BMP C151), Material Delivery, Storage and Containment (BMP (C153), Storm Drain Inlet Proection (BMP C220) Installation Schedules: Pollutant control elements shall be installed as needed and shall be maintained and adjusted as needed. Inspection and Maintenance plan: Pollutant control elements shall be inspected and maintained as necessary. Responsible Staff: CESCL Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? Yes No List and describe BMPs: Material Delivery, Storage and Containment BMP (C153) Installation Schedules: Pollution control elements shall be installed as needed and shall be maintained and adjusted as needed. Inspection and Maintenance plan: Pollution control elements shall be inspected and maintained as necessary. Responsible Staff: CESCL Will wheel wash or tire bath system BMPs be used during construction? Yes No Solera – DevCo, LLC Page 17 List and describe BMPs: Discharge wheel wash or tire bath wastewater to a separate onsite treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application, or to the sanitary sewer. For discharges to the sanitary sewer, permits must be obtained from the wastewater management agency presiding over the project site. Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. Installation Schedules: Wheel wash systems shall be installed beginning Grade and Fill construction. Wheel wash systems shall be onsite daily during construction, and may be used multiple times a day at contractor discretion. Inspection and Maintenance plan: Wheel was system shall be inspected and maintained as needed and after use. Responsible Staff: CESCL Will pH-modifying sources be present on-site? Yes No Table 3 – pH-Modifying Sources None Bulk cement Cement kiln dust Fly ash Other cementitious materials New concrete washing or curing waters Waste streams generated from concrete grinding and sawing Exposed aggregate processes Dewatering concrete vaults Y Concrete pumping and mixer washout waters Recycled concrete Other (i.e. calcium lignosulfate) [please describe] List and describe BMPs: Concrete Washout Area (BMP C154) All concrete washout waters shall be vaccumed while the work is actively occurring to prevent migration offsite, and shall not remain on existing asphalt or concrete surfaces. The washout waters shall be disposed of in a manner that does not violate surface water or groundwater quality standards. Solera – DevCo, LLC Page 18 Installation Schedules: BMPs relating to pH-modifying sources shall be implemented as necessary. Inspection and Maintenance plan: BMPs relating to pH-modifying sources shall be inspected and maintained as necessary. Responsible Staff: CESCL 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. Demolition: · Dust released from demolished sidewalks, buildings, or structures will be controlled using Dust Control measures (BMP C140). · Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or debris will be protected using Storm Drain Inlet Protection (BMP C220 as described above for Element 7). · 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). 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). Solera – DevCo, LLC Page 19 Element 10: Control Dewatering (2.1.10) All trench de-watering water shall be discharged into a controlled conveyance system before discharge to the sediment pond. Clean, non-turbid de-watering water, such as well-point ground water, shall be discharged 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. Clean de-watering water shall not be routed through the sediment pond. Table 4 – 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) List and describe BMPs: No BMPs are planned for dewatering. Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Solera – DevCo, LLC Page 20 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. Solera – DevCo, LLC Page 21 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 5 – Management Y Design the project to fit the existing topography, soils, and drainage patterns Y Emphasize erosion control rather than sediment control Y Minimize the extent and duration of the area exposed Y Keep runoff velocities low Y Retain sediment on-site Y Thoroughly monitor site and maintain all ESC measures Y Schedule major earthwork during the dry season Other (please describe) Solera – DevCo, LLC Page 22 Table 6 – BMP Implementation Schedule Phase of Construction Project Stormwater BMPs Date Wet/Dry Season [Insert construction activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] Solera – DevCo, LLC Page 23 Phase of Construction Project Stormwater BMPs Date Wet/Dry Season [Insert construction activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] Solera – DevCo, LLC Page 24 Element 13: Protect Low Impact Development (LID) BMPs (2.1.13) No LID BMPs are currently proposed for the Grade and Fill Phase of this project. The SWPPP will be amended for LIDs as part of the full Civil Construction plan. Pollution Prevention Team (3.0) Table 7 – Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD TBD Resident Engineer Michelle Freeman 206-622-5822 Emergency Ecology Contact Kendra Henderson 360-870-6757 Emergency Permittee/ Owner Contact TBD TBD Non-Emergency Owner Contact Tom Neubauer 425-452-4042 Monitoring Personnel TBD TBD Ecology Regional Office Rachel McCrea Northwest Regional Office 206-594-0146 Solera – DevCo, LLC Page 25 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 File a blank form under Appendix D. The site log book must be maintained on-site within reasonable access to the site 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. Complete the following paragraph for sites that discharge to impaired waterbodies for fine sediment, turbidity, phosphorus, or pH: 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. Solera – DevCo, LLC Page 26 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 8 – Turbidity Sampling Method Y 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. 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 · Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, Yakima): (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 (King, Kitsap, Island, San Juan, Skagit, Snohomish, Whatcom): (425) 649-7000 · Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300 Solera – DevCo, LLC Page 27 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: · Turbidity is 25 NTU (or lower). · Transparency is 33 cm (or greater). · Compliance with the water quality limit for turbidity is achieved. o 1 - 5 NTU over background turbidity, if background is less than 50 NTU o 1% - 10% over background turbidity, if background is 50 NTU or greater · The discharge stops or is eliminated. Solera – DevCo, LLC Page 28 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 9 – pH Sampling Method Y pH meter pH test kit Wide range pH indicator paper Solera – DevCo, LLC Page 29 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 Describe the method(s) for TMDL compliance: 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. The Construction Stormwater General Permit Proposed New Discharge to an Impaired Water Body form is included in Appendix E. Solera – DevCo, LLC Page 30 Reporting and Record Keeping (6.0) Record Keeping (6.1) 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. Solera – DevCo, LLC Page 31 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. Reporting (6.2) Discharge Monitoring Reports (6.2.1) Cumulative soil disturbance is less than one (1) acre; therefore, Discharge Monitoring Reports (DMRs) will not be submitted to Ecology because water quality sampling is not being conducted at the site. 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. 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: 1. Your name and / Phone number 2. Permit number Solera – DevCo, LLC Page 32 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. Solera – DevCo, LLC Page 33 Appendix Solera – DevCo, LLC Page 34 A. Site Plan 1. TESC Plans 2. TESC Details CITY OF RENTON IN COMPLIANCE WITH CITY OF RENTON STANDARDSTED-40-4178SOLERA2842 NE SUNSET BLVDRENTON, WA 98056SOLERA LUA20-000305C21-001020PR18-0003331601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com R Call 811two business daysbefore you dig NOT FOR CONSTRUCTION NW 1/4 OF THE NW 1/4 AND THE NE 1/4 OF THE NW 1/4 SECTION 9, TOWNSHIP 23 NORTH, RANGE 05 EAST, W.M. TESC PLAN 08/10/2021 CITY OF RENTON IN COMPLIANCE WITH CITY OF RENTON STANDARDSTED-40-4178SOLERA2842 NE SUNSET BLVDRENTON, WA 98056SOLERA LUA20-000305C21-001020PR18-0003331601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com R Call 811two business daysbefore you dig NOT FOR CONSTRUCTION NW 1/4 OF THE NW 1/4 AND THE NE 1/4 OF THE NW 1/4 SECTION 9, TOWNSHIP 23 NORTH, RANGE 05 EAST, W.M. TESC DETAILS 08/10/2021 CITY OF RENTON IN COMPLIANCE WITH CITY OF RENTON STANDARDSTED-40-4178SOLERA2842 NE SUNSET BLVDRENTON, WA 98056SOLERA LUA20-000305C21-001020PR18-0003331601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com R Call 811two business daysbefore you dig NOT FOR CONSTRUCTION NW 1/4 OF THE NW 1/4 AND THE NE 1/4 OF THE NW 1/4 SECTION 9, TOWNSHIP 23 NORTH, RANGE 05 EAST, W.M. TESC DETAILS 08/10/2021 CITY OF RENTON IN COMPLIANCE WITH CITY OF RENTON STANDARDSTED-40-4178SOLERA2842 NE SUNSET BLVDRENTON, WA 98056SOLERA LUA20-000305C21-001020PR18-0003331601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com R Call 811two business daysbefore you dig NOT FOR CONSTRUCTION NW 1/4 OF THE NW 1/4 AND THE NE 1/4 OF THE NW 1/4 SECTION 9, TOWNSHIP 23 NORTH, RANGE 05 EAST, W.M. TESC DETAILS 08/10/2021 Solera – DevCo, LLC Page 35 B. BMP Detail High Visibility Plastic or Metal Fence (BMP C103) Stabilized Construction Entrance (BMP C105) Wheel Wash (BMP C106) Temporary and Permanent Seeding (BMP C120) Nets and Blankets (BMP C122) Plastic Covering (BMP C123) Sodding (BMP C124) Topsoiling (BMP C125) Surface Roughening (BMP C130) Dust Control (BMP C140) Concrete Handling (BMP C151) Material Delivery, Storage, and Containment (BMP C153) Concrete Washout Area (BMP C154) Interceptor Dike and Swale (BMP C200) Check Dams (BMP C207) Storm Drain Inlet Protection (BMP C220) Silt Fence (BMP C233) Wattles (BMP C235) II-3 Construction Stormwater BMPs II-3.1 A Summary of Construction Stormwater BMPs This chapter contains standards and specifications for temporary BMPs, used as appropriate during  the construction phase of a project. Often using BMPs in combination is the best method to meet  Construction Stormwater Pollution Prevention Plan (Construction SWPPP) requirements. The standards  and specifications in this chapter are not intended to limit innovative efforts to effect- ively control erosion and sedimentation. Construction SWPPPs can contain experimental BMPs or  make minor modifications to standard BMPs. However, the permitting authority (state, local, or both)  must approve such practices before use. Experimental and modified BMPs must achieve the same  or better performance than the BMPs listed below. None of the BMPs listed below will work successfully throughout the construction project without  inspection and maintenance. Regular inspections to identify problems with the operation of each  BMP, and the timely repair of any problems are essential to the continued operation of the BMPs. As  site conditions change, BMPs must change to remain in compliance. Construction stormwater BMPs are divided into two categories: Construction Source Control BMPs  and Construction Runoff BMPs. Table II-3.1: Construction Stormwater BMPs by SWPPP Element shows the relationship of the Con- struction Stormwater BMPs to the Construction SWPPP Elements described in I-3.4.2 MR2: Con- struction Stormwater Pollution Prevention Plan (SWPPP). Construction Storm- water BMP Construction SWPPP Element # #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 Construction Source Control BMPs BMP C101: Preserving  Natural Vegetation ü              BMP C102: Buffer  Zones ü            ü BMP C103:  High-Vis- ibility Fence ü            ü BMP C105:  Stabilized  Construction Access  ü             BMP C106: Wheel  Wash  ü             Table II-3.1: Construction Stormwater BMPs by SWPPP Element 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 267 Construction Storm- water BMP Construction SWPPP Element # #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 BMP C107: Con- struction Road / Parking  Area Stabilization  ü             BMP C120: Temporary  and Permanent Seeding     ü ü         BMP C121: Mulching     ü ü         BMP C122:  Nets and  Blankets     ü ü  ü       BMP C123:  Plastic  Covering     ü ü         BMP C124:  Sodding     ü ü         BMP C125: Topsoiling /  Composting     ü          BMP C126:  Poly- acrylamide (PAM) for  Soil Erosion Protection     ü          BMP C130:  Surface  Roughening     ü ü         BMP C131:  Gradient  Terraces     ü ü         BMP C140:  Dust Con- trol     ü          BMP C150:  Mater- ials on Hand           ü ü   BMP C151: Concrete  Handling         ü      BMP C152:  Sawcutting  and Surfacing Pollution  Prevention         ü      BMP C153: Material  Delivery, Storage, and  Containment         ü      Table II-3.1: Construction Stormwater BMPs by SWPPP Element (continued) 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 268 Construction Storm- water BMP Construction SWPPP Element # #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 BMP C154: Concrete  Washout Area         ü      BMP C160:  Certified  Erosion and Sediment  Control Lead           ü ü   BMP C162:  Scheduling            ü   Construction Runoff BMPs BMP C200: Interceptor  Dike and Swale      ü       ü BMP C201: Grass- Lined Channels      ü       ü BMP C202:  Riprap  Channel Lining        ü       BMP C203: Water Bars   ü   ü    ü     BMP C204: Pipe Slope  Drains      ü         BMP C205:  Subsurface  Drains      ü         BMP C206:  Level  Spreader      ü    ü     BMP C207:  Check  Dams   ü   ü  ü     ü BMP C208:  Triangular  Silt Dike (TSD)      ü       ü BMP C209: Outlet Pro- tection   ü     ü       BMP C220:  Inlet Pro- tection       ü        BMP C231:  Brush Bar- rier    ü         ü BMP C232:  Gravel Fil- ter Berm    ü           Table II-3.1: Construction Stormwater BMPs by SWPPP Element (continued) 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 269 Construction Storm- water BMP Construction SWPPP Element # #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 BMP C233:  Silt Fence    ü         ü BMP C234:  Vegetated  Strip    ü         ü BMP C235:  Wattles   ü ü           BMP C236:  Vegetative  Filtration          ü     BMP C240:  Sediment  Trap   ü ü           BMP C241:  Sediment  Pond (Temporary)  ü ü           BMP C250:  Con- struction Stormwater  Chemical Treatment    ü     ü      BMP C251:  Con- struction Stormwater  Filtration    ü     ü      BMP C252:  Treating  and Disposing of High  pH Water         ü      Construction SWPPP Elements: Element 1: Preserve Vegetation  /  Mark Clearing Limits Element 2: Establish Construction Access Element 3: Control Flow Rates Element 4: Install Sediment Controls Element 5: Stabilize Soils Element 6: Protect Slopes Element 7: Protect Drain Inlets Element 8: Stabilize Channels and Outlets Element 9: Control Pollutants Element 10: Control Dewatering Element 11: Maintain BMPs Element 12: Manage the Project Element 13: Protect Low Impact Development BMPs Table II-3.1: Construction Stormwater BMPs by SWPPP Element (continued) II-3.2 Construction Source Control BMPs 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 270 burying and smothering vegetation.  l Vegetative buffer zones for streams, lakes or other waterways shall be established by the  local permitting authority or other state or federal permits or approvals. Maintenance Standards Inspect the area frequently to make sure flagging remains in place and the area remains undis- turbed. Replace all damaged flagging immediately. Remove all materials located in the buffer area  that may impede the ability of the vegetation to act as a filter. BMP C103: High-Visibility Fence Purpose High-visibility fencing is intended to:  l Restrict clearing to approved limits.  l Prevent disturbance of sensitive areas, their buffers, and other areas required to be left undis- turbed.  l Limit construction traffic to designated construction entrances, exits, or internal roads.  l Protect areas where marking with survey tape may not provide adequate protection. Conditions of Use To establish clearing limits plastic, fabric, or metal fence may be used:  l At the boundary of sensitive areas, their buffers, and other areas required to be left uncleared.  l As necessary to control vehicle access to and on the site. Design and Installation Specifications High-visibility plastic fence shall be composed of a high-density polyethylene material and shall be at  least four feet in height. Posts for the fencing shall be steel or wood and placed every 6 feet on center  (maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches  with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as  a top stringer to prevent sagging between posts. The fence color shall be high-visibility orange. The  fence tensile strength shall be 360 lbs/ft using the ASTM D4595 testing method. If appropriate install fabric silt fence in accordance with BMP C233:  Silt Fence to act as high-visibility  fence. Silt fence shall be at least 3 feet high and must be highly visible to meet the requirements of  this BMP. Metal fences shall be designed and installed according to the manufacturer's specifications. Metal fences shall be at least 3 feet high and must be highly visible. Fences shall not be wired or stapled to trees. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 274 Maintenance Standards If the fence has been damaged or visibility reduced, it shall be repaired or replaced immediately and  visibility restored. BMP C105: Stabilized Construction Access Purpose Stabilized construction accesses are established to reduce the amount of sediment transported onto  paved roads outside the project site by vehicles or equipment. This is done by constructing a sta- bilized pad of quarry spalls at entrances and exits for project sites. Conditions of Use Construction accesses shall be stabilized wherever traffic will be entering or leaving a construction  site if paved roads or other paved areas are within 1,000 feet of the site. For residential subdivision construction sites, provide a stabilized construction access for each res- idence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient  length/width to provide vehicle access/parking, based on lot size and configuration. On large commercial, highway, and road projects, the designer should include enough extra mater- ials in the contract to allow for additional stabilized accesses not shown in the initial Construction  SWPPP. It is difficult to determine exactly where access to these projects will take place; additional  materials will enable the contractor to install them where needed. Design and Installation Specifications See Figure II-3.1: Stabilized Construction Access for details. Note: the 100’ minimum length of the  access shall be reduced to the maximum practicable size when the size or configuration of the site  does not allow the full length (100’). Construct stabilized construction accesses with a 12-inch thick pad of 4-inch to 8-inch quarry spalls,  a 4-inch course of asphalt treated base (ATB), or use existing pavement. Do not use crushed con- crete, cement, or calcium chloride for construction access stabilization because these products raise  pH levels in stormwater and concrete discharge to waters of the State is prohibited. A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up  into the rock pad. The geotextile shall meet the standards listed in Table II-3.2: Stabilized Con- struction Access Geotextile Standards. Geotextile Property Required Value Grab Tensile  Strength (ASTM D4751)200  psi min. Table II-3.2: Stabilized Construction Access Geotextile Standards 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 275 Geotextile Property Required Value Grab Tensile  Elongation (ASTM D4632)30%  max. Mullen Burst  Strength (ASTM D3786-80a)400  psi min. AOS (ASTM D4751)20-45  (U.S. standard sieve size) Table II-3.2: Stabilized Construction Access Geotextile Standards (continued)  l Consider early installation of the first lift of asphalt in areas that will be paved; this can be used  as a stabilized access. Also consider the installation of excess concrete as a stabilized access.  During large concrete pours, excess concrete is often available for this purpose.  l Fencing (see BMP C103:  High-Visibility Fence) shall be installed as necessary to restrict  traffic to the construction access.  l Whenever possible, the access shall be constructed on a firm, compacted subgrade. This can  substantially increase the effectiveness of the pad and reduce the need for maintenance.  l Construction accesses should avoid crossing existing sidewalks and back of walk drains if at  all possible. If a construction access must cross a sidewalk or back of walk drain, the full length  of the sidewalk and back of walk drain must be covered and protected from sediment leaving  the site. Alternative Material Specification WSDOT has raised safety concerns about the Quarry Spall rock specified above. WSDOT observes  that the 4-inch to 8-inch rock sizes can become trapped between Dually truck tires, and then  released off-site at highway speeds. WSDOT has chosen to use a modified specification for the rock  while continuously verifying that the Stabilized Construction Access remains effective. To remain  effective, the BMP must prevent sediment from migrating off site. To date, there has been no per- formance testing to verify operation of this new specification. Jurisdictions may use the alternative  specification, but must perform increased off-site inspection if they use, or allow others to use, it. Stabilized Construction Accesses may use material that meets the requirements of WSDOT's Stand- ard Specifications for Road, Bridge, and Municipal Construction Section 9-03.9(1) (WSDOT, 2016)  for ballast except for the following special requirements. The grading and quality requirements are listed in Table II-3.3: Stabilized Construction Access  Alternative Material Requirements. Sieve Size Percent Passing 2½″99-100 Table II-3.3: Stabilized Construction Access Alternative Material Requirements 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 276 Sieve Size Percent Passing 2″65-100 ¾″40-80 No. 4 5 max. No. 100 0-2 % Fracture 75 min. Table II-3.3: Stabilized Construction Access Alternative Material Requirements (continued)  l All percentages are by weight.  l The sand equivalent value and dust ratio requirements do not apply.  l The fracture requirement shall be at least one fractured face and will apply the combined  aggregate retained on the No. 4 sieve in accordance with FOP for AASHTO T 335. Maintenance Standards Quarry spalls shall be added if the pad is no longer in accordance with the specifications.  l If the access is not preventing sediment from being tracked onto pavement, then alternative  measures to keep the streets free of sediment shall be used. This may include replace- ment/cleaning of the existing quarry spalls, street sweeping, an increase in the dimensions of  the access, or the installation of BMP C106: Wheel Wash.  l Any sediment that is tracked onto pavement shall be removed by shoveling or street sweep- ing. The sediment collected by sweeping shall be removed or stabilized on site. The pavement  shall not be cleaned by washing down the street, except when high efficiency sweeping is inef- fective and there is a threat to public safety. If it is necessary to wash the streets, the con- struction of a small sump to contain the wash water shall be considered. The sediment would  then be washed into the sump where it can be controlled.  l Perform street sweeping by hand or with a high efficiency sweeper. Do not use a non-high effi- ciency mechanical sweeper because this creates dust and throws soils into storm systems or  conveyance ditches.  l Any quarry spalls that are loosened from the pad, which end up on the roadway shall be  removed immediately.  l If vehicles are entering or exiting the site at points other than the construction access(es),  BMP C103:  High-Visibility Fence shall be installed to control traffic. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 277  l Upon project completion and site stabilization, all construction accesses intended as per- manent access for maintenance shall be permanently stabilized. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 278 Figure II-3.1: Stabilized Construction Access 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 279 Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C106: Wheel Wash Purpose Wheel washes reduce the amount of sediment transported onto paved roads by washing dirt from  the wheels of motor vehicles prior to the motor vehicles leaving the construction site. Conditions of Use  l Use a wheel wash when BMP C105:  Stabilized Construction Access is not preventing sed- iment from being tracked off site.  l Wheel washing is generally an effective BMP when installed with careful attention to topo- graphy. For example, a wheel wash can be detrimental if installed at the top of a slope abut- ting a right-of-way where the water from the dripping truck can run unimpeded into the street.  l Pressure washing combined with an adequately sized and surfaced pad with direct drainage  to a large 10-foot x 10-foot sump can be very effective.  l Wheel wash wastewater is not stormwater. It is commonly called process water, and must be  discharged to a separate on-site treatment system that prevents discharge to waters of the  State, or to the sanitary sewer with local sewer district approval.  l Wheel washes may use closed-loop recirculation systems to conserve water use.  l Wheel wash wastewater shall not include wastewater from concrete washout areas.  l When practical, the wheel wash should be placed in sequence with BMP C105:  Stabilized  Construction Access. Locate the wheel wash such that vehicles exiting the wheel wash will  enter directly onto BMP C105:  Stabilized Construction Access. In order to achieve this, BMP  C105:  Stabilized Construction Access may need to be extended beyond the standard install- ation to meet the exit of the wheel wash. Design and Installation Specifications Suggested details are shown in Figure II-3.2: Wheel Wash. The Local Permitting Authority may  allow other designs. A minimum of 6 inches of asphalt treated base (ATB) over crushed base mater- ial or 8 inches over a good subgrade is recommended to pave the wheel wash. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 280 Use a low clearance truck to test the wheel wash before paving. Either a belly dump or lowboy will  work well to test clearance. Keep the water level from 12 to 14 inches deep to avoid damage to truck hubs and filling the truck  tongues with water. Midpoint spray nozzles are only needed in extremely muddy conditions. Wheel wash systems should be designed with a small grade change, 6- to 12-inches for a 10-foot- wide pond, to allow sediment to flow to the low side of pond to help prevent re-suspension of sed- iment. A drainpipe with a 2- to 3-foot riser should be installed on the low side of the pond to allow for  easy cleaning and refilling. Polymers may be used to promote coagulation and flocculation in a  closed-loop system. Polyacrylamide (PAM) added to the wheel wash water at a rate of 0.25 - 0.5  pounds per 1,000 gallons of water increases effectiveness and reduces cleanup time. If PAM is  already being used for dust or erosion control and is being applied by a water truck, the same truck  can be used to change the wash water. Maintenance Standards The wheel wash should start out each day with fresh water. The wheel wash water should be changed a minimum of once per day. On large earthwork jobs  where more than 10-20 trucks per hour are expected, the wheel wash water will need to be changed  more often. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 281 Figure II-3.2: Wheel Wash 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 282 Crushed rock, gravel base, etc., shall be added as required to maintain a stable driving surface and  to stabilize any areas that have eroded. Following construction, these areas shall be restored to pre-construction condition or better to pre- vent future erosion. Perform street cleaning at the end of each day or more often if necessary. BMP C120: Temporary and Permanent Seeding Purpose Seeding reduces erosion by stabilizing exposed soils. A well-established vegetative cover is one of  the most effective methods of reducing erosion. Conditions of Use Use seeding throughout the project on disturbed areas that have reached final grade or that will  remain unworked for more than 30 days. The optimum seeding windows for western Washington are April 1 through June 30 and September  1 through October 1. Between July 1 and August 30 seeding requires irrigation until 75 percent grass cover is established. Between October 1 and March 30 seeding requires a cover of mulch or an erosion control blanket  until 75 percent grass cover is established. Review all disturbed areas in late August to early September and complete all seeding by the end of  September. Otherwise, vegetation will not establish itself enough to provide more than average pro- tection. Mulch is required at all times for seeding because it protects seeds from heat, moisture loss, and  transport due to runoff. Mulch can be applied on top of the seed or simultaneously by hydroseeding.  See BMP C121: Mulching for specifications. Seed and mulch all disturbed areas not otherwise vegetated at final site stabilization. Final sta- bilization 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. See BMP T5.13: Post-Construction Soil  Quality and Depth. Design and Installation Specifications General  l Install channels intended for vegetation before starting major earthwork and hydroseed with a  Bonded Fiber Matrix. For vegetated channels that will have high flows, install erosion control  blankets over the top of hydroseed. Before allowing water to flow in vegetated channels,  establish 75 percent vegetation cover. If vegetated channels cannot be established by seed  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 284 before water flow; install sod in the channel bottom — over top of hydromulch and erosion con- trol blankets.  l Confirm the installation of all required surface water control measures to prevent seed from  washing away.  l Hydroseed applications shall include a minimum of 1,500 pounds per acre of mulch with 3 per- cent tackifier. See BMP C121: Mulching for specifications.  l Areas that will have seeding only and not landscaping may need compost or meal-based  mulch included in the hydroseed in order to establish vegetation. Re-install native topsoil on  the disturbed soil surface before application. See BMP T5.13: Post-Construction Soil Quality  and Depth.  l When installing seed via hydroseeding operations, only about 1/3 of the seed actually ends up  in contact with the soil surface. This reduces the ability to establish a good stand of grass  quickly. To overcome this, consider increasing seed quantities by up to 50 percent.  l Enhance vegetation establishment by dividing the hydromulch operation into two phases:  o Phase 1- Install all seed and fertilizer with 25-30 percent mulch and tackifier onto soil in  the first lift.  o Phase 2- Install the rest of the mulch and tackifier over the first lift. Or, enhance vegetation by:  o Installing the mulch, seed, fertilizer, and tackifier in one lift.  o Spread or blow straw over the top of the hydromulch at a rate of 800-1000 pounds per  acre.  o Hold straw in place with a standard tackifier. Both of these approaches will increase cost moderately but will greatly improve and enhance  vegetative establishment. The increased cost may be offset by the reduced need for:  o Irrigation.  o Reapplication of mulch.  o Repair of failed slope surfaces. This technique works with standard hydromulch (1,500 pounds per acre minimum) and Bon- ded Fiber Matrix/ Mechanically Bonded Fiber Matrix (BFM/MBFMs) (3,000 pounds per acre  minimum).  l Seed may be installed by hand if:  o Temporary and covered by straw, mulch, or topsoil.  o Permanent in small areas (usually less than 1 acre) and covered with mulch, topsoil, or  erosion blankets.  l The seed mixes listed in Table II-3.4: Temporary and Permanent Seed Mixes include  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 285 recommended mixes for both temporary and permanent seeding.  l Apply these mixes, with the exception of the wet area seed mix, at a rate of 120 pounds per  acre. This rate can be reduced if soil amendments or slow-release fertilizers are used. Apply  the wet area seed mix at a rate of 60 pounds per acre.  l Consult the local suppliers or the local conservation district for their recommendations. The  appropriate mix depends on a variety of factors, including location, exposure, soil type, slope,  and expected foot traffic. Alternative seed mixes approved by the local authority may be used,  depending on the soil type and hydrology of the area. Common Name Latin Name % Weight % Purity % Germination Temporary Erosion Control Seed Mix A standard mix for areas requiring a temporary vegetative cover. Chewings or   annual blue grass Festuca rubra var. commutata or Poa anna 40 98 90 Perennial rye  Lolium perenne 50 98 90 Redtop or colonial  bentgrass  Agrostis alba or  Agrostis tenuis 5 92 85 White dutch clover Trifolium repens 5 98 90 Landscaping Seed Mix A recommended mix for landscaping seed. Perennial rye blend Lolium perenne 70 98 90 Chewings and red  fescue blend Festuca rubra var. commutata or Fes- tuca rubra 30 98 90 Low-Growing Turf Seed Mix A turf seed mix for dry situations where there is no need for watering. This mix requires very little main- tenance. Dwarf tall fescue  (several  varieties) Festuca arundin- acea var. 45 98 90 Dwarf perennial  rye (Barclay) Lolium perenne var. barclay 30 98 90 Red fescue Festuca rubra 20 98 90 Colonial bentgrass Agrostis tenuis 5 98 90 Bioswale Seed Mix A seed mix for bioswales and other intermittently wet areas. Tall or meadow fes-Festuca arundin-75-80 98 90 Table II-3.4: Temporary and Permanent Seed Mixes 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 286 Common Name Latin Name % Weight % Purity % Germination cue acea or   Festuca elatior Seaside/Creeping  bentgrass Agrostis palustris 10-15 92 85 Redtop bentgrass Agrostis alba or  Agrostis gigantea 5-10 90 80 Wet Area Seed Mix A low-growing, relatively non-invasive seed mix appropriate for very wet areas that are not regulated wet- lands. Consult Hydraulic Permit Authority (HPA) for seed mixes if applicable. Tall or meadow fes- cue Festuca arundin- acea or Festuca elatior 60-70 98 90 Seaside/Creeping  bentgrass Agrostis palustris 10-15 98 85 Meadow foxtail Alepocurus praten- sis 10-15 90 80 Alsike clover Trifolium hybridum 1-6 98 90 Redtop bentgrass Agrostis alba 1-6 92 85 Meadow Seed Mix A recommended meadow seed mix for infrequently maintained areas or non-maintained areas where col- onization by native plants is desirable. Likely applications include rural road and utility right-of-way. Seed- ing should take place in September or very early October in order to obtain adequate establishment prior to  the winter months. Consider the appropriateness of clover, a fairly invasive species, in the mix. Amending  the soil can reduce the need for clover. Redtop or Oregon  bentgrass Agrostis alba or  Agrostis ore- gonensis 20 92 85 Red fescue Festuca rubra 70 98 90 White dutch clover Trifolium repens 10 98 90 Table II-3.4: Temporary and Permanent Seed Mixes (continued) Roughening and Rototilling  l The seedbed should be firm and rough. Roughen all soil no matter what the slope. Track walk  slopes before seeding if engineering purposes require compaction. Backblading or smoothing  of slopes greater than 4H:1V is not allowed if they are to be seeded.  l Restoration-based landscape practices require deeper incorporation than that provided by a  simple single-pass rototilling treatment. Wherever practical, initially rip the subgrade to  improve long-term permeability, infiltration, and water inflow qualities. At a minimum,  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 287 permanent areas shall use soil amendments to achieve organic matter and permeability per- formance defined in engineered soil/landscape systems. For systems that are deeper than 8  inches complete the rototilling process in multiple lifts, or prepare the engineered soil system  per specifications and place to achieve the specified depth. Fertilizers  l Conducting soil tests to determine the exact type and quantity of fertilizer is recommended.  This will prevent the over-application of fertilizer.  l Organic matter is the most appropriate form of fertilizer because it provides nutrients (includ- ing nitrogen, phosphorus, and potassium) in the least water-soluble form.  l In general, use 10-4-6 N-P-K (nitrogen-phosphorus-potassium) fertilizer at a rate of 90  pounds per acre. Always use slow-release fertilizers because they are more efficient and  have fewer environmental impacts. Do not add fertilizer to the hydromulch machine, or agit- ate, more than 20 minutes before use. Too much agitation destroys the slow-release coating.  l There are numerous products available that take the place of chemical fertilizers. These  include several with seaweed extracts that are beneficial to soil microbes and organisms. If  100 percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be  necessary. Cottonseed meal provides a good source of long-term, slow-release, available  nitrogen. Bonded Fiber Matrix and Mechanically Bonded Fiber Matrix  l On steep slopes use Bonded Fiber Matrix (BFM) or Mechanically Bonded Fiber Matrix  (MBFM) products. Apply BFM/MBFM products at a minimum rate of 3,000 pounds per acre  with approximately 10 percent tackifier. Achieve a minimum of 95 percent soil coverage during  application. Numerous products are available commercially. Most products require 24-36  hours to cure before rainfall and cannot be installed on wet or saturated soils. Generally,  products come in 40-50 pound bags and include all necessary ingredients except for seed and  fertilizer.  l Install products per manufacturer's instructions.  l BFMs and MBFMs provide good alternatives to blankets in most areas requiring vegetation  establishment. Advantages over blankets include:  o BFM and MBFMs do not require surface preparation.  o Helicopters can assist in installing BFM and MBFMs in remote areas.  o On slopes steeper than 2.5H:1V, blanket installers may require ropes and harnesses  for safety.  o Installing BFM and MBFMs can save at least $1,000 per acre compared to blankets. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 288 Maintenance Standards Reseed any seeded areas that fail to establish at least 75 percent cover (100 percent cover for areas  that receive sheet or concentrated flows). If reseeding is ineffective, use an alternate method such  as sodding, mulching, nets, or blankets.  l Reseed and protect by mulch any areas that experience erosion after achieving adequate  cover. Reseed and protect by mulch any eroded area.  l Supply seeded areas with adequate moisture, but do not water to the extent that it causes run- off. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C121: Mulching Purpose Mulching soils provides immediate temporary protection from erosion. Mulch also enhances plant  establishment by conserving moisture, holding fertilizer, seed, and topsoil in place, and moderating  soil temperatures. There are a variety of mulches that can be used. This section discusses only the  most common types of mulch. Conditions of Use As a temporary cover measure, mulch should be used:  l For less than 30 days on disturbed areas that require cover.  l At all times for seeded areas, especially during the wet season and during the hot summer  months.  l During the wet season on slopes steeper than 3H:1V with more than 10 feet of vertical relief. Mulch may be applied at any time of the year and must be refreshed periodically. For seeded areas, mulch may be made up of 100 percent:   l cottonseed meal;   l fibers made of wood, recycled cellulose, hemp, or kenaf;  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 289 Mulch Mater- ial Guideline Description Remarks This is a cost-effective way to dispose of debris from clearing and grub- bing, and it eliminates the problems associated with burning. Generally, it  should not be used on slopes above approx. 10% because of its tendency  to be transported by runoff. It is not recommended within 200 feet of sur- face waters. If permanent seeding or planting is expected shortly after  mulch, the decomposition of the chipped vegetation may tie up nutrients  important to grass establishment.  Note: thick application of this material over existing grass, herbaceous spe- cies, and some groundcovers could smother and kill vegetation. Wood- Based Mulch Quality Standards No visible water or dust during handling. Must be purchased from a supplier  with a Solid Waste Handling Permit or one exempt from solid waste reg- ulations. Application Rates 2" thick min.; approx. 100 tons per acre (approx. 750 lbs. per cubic yard) Remarks This material is often called "wood straw" or "hog fuel". The use of mulch  ultimately improves the organic matter in the soil. Special caution is  advised regarding the source and composition of wood-based mulches. Its  preparation typically does not provide any weed seed control, so evidence  of residual vegetation in its composition or known inclusion of weed plants  or seeds should be monitored and prevented (or minimized). Wood Strand Mulch Quality Standards A blend of loose, long, thin wood pieces derived from native conifer or  deciduous trees with high length-to-width ratio. Application Rates 2" thick min. Remarks Cost-effective protection when applied with adequate thickness. A min- imum of 95-percent of the wood strand shall have lengths between 2 and  10-inches, with a width and thickness between 1/16 and 1/2-inches. The  mulch shall not contain resin, tannin, or other compounds in quantities that  would be detrimental to plant life. Sawdust or wood shavings shall not be  used as mulch. [Specification 9-14.4(4) from the Standard Specifications for Road, Bridge, and Municipal Construction (WSDOT, 2016) Table II-3.6: Mulch Standards and Guidelines (continued) BMP C122: Nets and Blankets Purpose Erosion control nets and blankets are intended to prevent erosion and hold seed and mulch in place  on steep slopes and in channels so that vegetation can become well established. In addition, some  nets and blankets can be used to permanently reinforce turf to protect drainage ways during high  flows.  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 292 Nets (commonly called matting) are strands of material woven into an open, but high-tensile strength  net (for example, coconut fiber matting). Blankets are strands of material that are not tightly woven,  but instead form a layer of interlocking fibers, typically held together by a biodegradable or pho- todegradable netting (for example, excelsior or straw blankets). They generally have lower tensile  strength than nets, but cover the ground more completely. Coir (coconut fiber) fabric comes as both  nets and blankets. Conditions of Use Erosion control netting and blankets shall be made of natural plant fibers unaltered by synthetic  materials. Erosion control nets and blankets should be used:  l To aid permanent vegetated stabilization of slopes 2H:1V or greater and with more than 10  feet of vertical relief.  l For drainage ditches and swales (highly recommended). The application of appropriate net- ting or blanket to drainage ditches and swales can protect bare soil from channelized runoff  while vegetation is established. Nets and blankets also can capture a great deal of sediment  due to their open, porous structure. Nets and blankets can be used to permanently stabilize  channels and may provide a cost-effective, environmentally preferable alternative to riprap. Disadvantages of nets and blankets include:  l Surface preparation is required.  l On slopes steeper than 2.5H:1V, net and blanket installers may need to be roped and har- nessed for safety.  l They cost at least $4,000-6,000 per acre installed. Advantages of nets and blankets include:  l Installation without mobilizing special equipment.  l Installation by anyone with minimal training  l Installation in stages or phases as the project progresses.  l Installers can hand place seed and fertilizer as they progress down the slope.  l Installation in any weather.  l There are numerous types of nets and blankets that can be designed with various parameters  in mind. Those parameters include: fiber blend, mesh strength, longevity, biodegradability,  cost, and availability. An alternative to nets and blankets in some limited conditions is BMP C202:  Riprap Channel Lining.  Ensure that BMP C202:  Riprap Channel Lining is appropriate before using it as a substitute for nets  and blankets. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 293 Design and Installation Specifications  l See Figure II-3.3: Channel Installation (Clackamas County et al., 2008) and Figure II-3.4:  Slope Installation for typical orientation and installation of nets and blankets used in channels  and as slope protection. Note: these are typical only; all nets and blankets must be installed  per manufacturer’s installation instructions.  l Installation is critical to the effectiveness of these products. If good ground contact is not  achieved, runoff can concentrate under the product, resulting in significant erosion.  l Installation of nets and blankets on slopes:  1. Complete final grade and track walk up and down the slope.  2. Install hydromulch with seed and fertilizer.  3. Dig a small trench, approximately 12 inches wide by 6 inches deep along the top of the  slope.  4. Install the leading edge of the net/blanket into the small trench and staple approximately  every 18 inches. NOTE: Staples are metal, “U”-shaped, and a minimum of 6 inches  long. Longer staples are used in sandy soils. Biodegradable stakes are also available.  5. Roll the net/blanket slowly down the slope as the installer walks backward. NOTE: The  net/blanket rests against the installer’s legs. Staples are installed as the net/blanket is  unrolled. It is critical that the proper staple pattern is used for the net/blanket being  installed. The net/blanket is not to be allowed to roll down the slope on its own as this  stretches the net/blanket, making it impossible to maintain soil contact. In addition, no  one is allowed to walk on the net/blanket after it is in place.  6. If the net/blanket is not long enough to cover the entire slope length, the trailing edge of  the upper net/blanket should overlap the leading edge of the lower net/blanket and be  stapled. On steeper slopes, this overlap should be installed in a small trench, stapled,  and covered with soil.  l With the variety of products available, it is impossible to cover all the details of appropriate use  and installation. Therefore, it is critical that the designer consult the manufacturer's inform- ation and that a site visit takes place in order to ensure that the product specified is appro- priate. Information is also available in WSDOT's Standard Specifications for Road, Bridge, and Municipal Construction Division 8-01 and Division 9-14 (WSDOT, 2016).  l Use jute matting in conjunction with mulch (BMP C121: Mulching). Excelsior, woven straw  blankets and coir (coconut fiber) blankets may be installed without mulch. There are many  other types of erosion control nets and blankets on the market that may be appropriate in cer- tain circumstances.  l In general, most nets (e.g., jute matting) require mulch in order to prevent erosion because  they have a fairly open structure. Blankets typically do not require mulch because they usually  provide complete protection of the surface.  l Extremely steep, unstable, wet, or rocky slopes are often appropriate candidates for use of  synthetic blankets, as are riverbanks, beaches and other high-energy environments. If  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 294 synthetic blankets are used, the soil should be hydromulched first.  l 100-percent biodegradable blankets are available for use in sensitive areas. These organic  blankets are usually held together with a paper or fiber mesh and stitching which may last up  to a year.  l Most netting used with blankets is photodegradable, meaning it breaks down under sunlight  (not UV stabilized). However, this process can take months or years even under bright sun.  Once vegetation is established, sunlight does not reach the mesh. It is not uncommon to find  non-degraded netting still in place several years after installation. This can be a problem if  maintenance requires the use of mowers or ditch cleaning equipment. In addition, birds and  small animals can become trapped in the netting. Maintenance Standards  l Maintain good contact with the ground. Erosion must not occur beneath the net or blanket.  l Repair and staple any areas of the net or blanket that are damaged or not in close contact with  the ground.  l Fix and protect eroded areas if erosion occurs due to poorly controlled drainage. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 295 Figure II-3.3: Channel Installation 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 296 Figure II-3.4: Slope Installation 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 297 BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of Use Plastic covering may be used on disturbed areas that require cover measures for less than 30 days,  except as stated below.  l Plastic is particularly useful for protecting cut and fill slopes and stockpiles. However, the rel- atively rapid breakdown of most polyethylene sheeting makes it unsuitable for applications  greater than six months.  l Due to rapid runoff caused by plastic covering, do not use this method upslope of areas that  might be adversely impacted by concentrated runoff. Such areas include steep and/or  unstable slopes.  l Plastic sheeting may result in increased runoff volumes and velocities, requiring additional on- site measures to counteract the increases. Creating a trough with wattles or other material  can convey clean water away from these areas.  l To prevent undercutting, trench and backfill rolled plastic covering products.  l Although the plastic material is inexpensive to purchase, the cost of installation, maintenance,  removal, and disposal add to the total costs of this BMP.  l Whenever plastic is used to protect slopes, install water collection measures at the base of the  slope. These measures include plastic-covered berms, channels, and pipes used to convey  clean rainwater away from bare soil and disturbed areas. Do not mix clean runoff from a  plastic covered slope with dirty runoff from a project.  l Other uses for plastic include:  o Temporary ditch liner.  o Pond liner in temporary sediment pond.  o Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel  being stored.  o Emergency slope protection during heavy rains.  o Temporary drainpipe (“elephant trunk”) used to direct water. Design and Installation Specifications  l Plastic slope cover must be installed as follows:  1. Run plastic up and down the slope, not across the slope.  2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 298  3. Provide a minimum of 8-inch overlap at the seams.  4. On long or wide slopes, or slopes subject to wind, tape all seams.  5. Place plastic into a small (12-inch wide by 6-inch deep) slot trench at the top of the slope  and backfill with soil to keep water from flowing underneath.  6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and tie them  together with twine to hold them in place.  7. Inspect plastic for rips, tears, and open seams regularly and repair immediately. This  prevents high velocity runoff from contacting bare soil, which causes extreme erosion.  8. Sandbags may be lowered into place tied to ropes. However, all sandbags must be  staked in place.  l Plastic sheeting shall have a minimum thickness of 0.06 millimeters.  l If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall  be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance Standards  l Torn sheets must be replaced and open seams repaired.  l Completely remove and replace the plastic if it begins to deteriorate due to ultraviolet radi- ation.  l Completely remove plastic when no longer needed.  l Dispose of old tires used to weight down plastic sheeting appropriately. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C124: Sodding Purpose The purpose of sodding is to establish turf for immediate erosion protection and to stabilize drainage  paths where concentrated overland flow will occur. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 299 Conditions of Use Sodding may be used in the following areas:  l Disturbed areas that require short-term or long-term cover.  l Disturbed areas that require immediate vegetative cover.  l All waterways that require vegetative lining. Waterways may also be seeded rather than sod- ded, and protected with a net or blanket. Design and Installation Specifications Sod shall be free of weeds, of uniform thickness (approximately 1-inch thick), and shall have a dense  root mat for mechanical strength. The following steps are recommended for sod installation:  1. Shape and smooth the surface to final grade in accordance with the approved grading plan.  Consider any areas (such as swales) that  need to be overexcavated below design elevation to  allow room for placing soil amendment and sod.  2. Amend 4 inches (minimum) of compost into the top 8 inches of the soil if the organic content of  the soil is less than ten percent or the permeability is less than 0.6 inches per hour. See  https://ecology.wa.gov/Waste-Toxics/Reducing-recycling-waste/Organic-mater- ials/Managing-organics-compost for further information.  3. Fertilize according to the sod supplier's recommendations.  4. Work lime and fertilizer 1 to 2 inches into the soil, and smooth the surface.  5. Lay strips of sod beginning at the lowest area to be sodded and perpendicular to the direction  of water flow. Wedge strips securely into place. Square the ends of each strip to provide for a  close, tight fit. Stagger joints at least 12 inches. Staple on slopes steeper than 3H:1V. Staple  the upstream edge of each sod strip.  6. Roll the sodded area and irrigate.  7. When sodding is carried out in alternating strips or other patterns, seed the areas between the  sod immediately after sodding. Maintenance Standards If the grass is unhealthy, the cause shall be determined and appropriate action taken to reestablish a  healthy groundcover. If it is impossible to establish a healthy groundcover due to frequent saturation,  instability, or some other cause, the sod shall be removed, the area seeded with an appropriate mix,  and protected with a net or blanket. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 300 BMP C125: Topsoiling / Composting Purpose Topsoiling and composting provide a suitable growth medium for final site stabilization with veget- ation. While not a permanent cover practice in itself, topsoiling and composting are an integral com- ponent of providing permanent cover in those areas where there is an unsuitable soil surface for  plant growth. Use this BMP in conjunction with other BMPs such as BMP C120: Temporary and Per- manent Seeding, BMP C121: Mulching, or BMP C124:  Sodding. Implementation of this BMP may  meet the post-construction requirements of BMP T5.13: Post-Construction Soil Quality and Depth. Native soils and disturbed soils that have been organically amended not only retain much more  stormwater, but also serve as effective biofilters for urban pollutants and, by supporting more vig- orous plant growth, reduce the water, fertilizer and pesticides needed to support installed land- scapes. Topsoil does not include any subsoils but only the material from the top several inches  including organic debris. Conditions of Use  l Permanent landscaped areas shall contain healthy topsoil that reduces the need for fertilizers,  improves overall topsoil quality, provides for better vegetative health and vitality, improves  hydrologic characteristics, and reduces the need for irrigation.  l Leave native soils and the duff layer undisturbed to the maximum extent practicable. Stripping  of existing, properly functioning soil system and vegetation for the purpose of topsoiling during  construction is not acceptable. Preserve existing soil systems in undisturbed and uncom- pacted conditions if functioning properly.  l Areas that already have good topsoil, such as undisturbed areas, do not require soil amend- ments.  l Restore, to the maximum extent practical, native soils disturbed during clearing and grading to  a condition equal to or better than the original site condition’s moisture-holding capacity. Use  on-site native topsoil, incorporate amendments into on-site soil, or import blended topsoil to  meet this requirement.  l Topsoiling is a required procedure when establishing vegetation on shallow soils, and soils of  critically low pH (high acid) levels.  l Beware of where the topsoil comes from, and what vegetation was on site before disturbance.  Invasive plant seeds may be included and could cause problems for establishing native plants,  landscaped areas, or grasses.  l Topsoil from the site will contain mycorrhizal bacteria that are necessary for healthy root  growth and nutrient transfer. These native mycorrhiza are acclimated to the site and will  provide optimum conditions for establishing grasses. Use commercially available mycorrhiza  products when using off-site topsoil. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 301 Design and Installation Specifications Meet the following requirements for disturbed areas that will be developed as lawn or landscaped  areas at the completed project site:  l Maximize the depth of the topsoil wherever possible to provide the maximum possible infilt- ration capacity and beneficial growth medium. Topsoil shall have:  o A minimum depth of 8-inches. Scarify subsoils below the topsoil layer at least 4-inches  with some incorporation of the upper material to avoid stratified layers, where feasible.  Ripping or re-structuring the subgrade may also provide additional benefits regarding  the overall infiltration and interflow dynamics of the soil system.  o A minimum organic content of 10% dry weight in planting beds, and 5% organic matter  content in turf areas. Incorporate organic amendments to a minimum 8-inch depth  except where tree roots or other natural features limit the depth of incorporation.  o A pH between 6.0 and 8.0 or matching the pH of the undisturbed soil.  o If blended topsoil is imported, then fines should be limited to 25 percent passing through  a 200 sieve.  l Mulch planting beds with 2 inches of organic material  l Accomplish the required organic content, depth, and pH by returning native topsoil to the site,  importing topsoil of sufficient organic content, and/or incorporating organic amendments.  When using the option of incorporating amendments to meet the organic content requirement,  use compost that meets the compost specification for Bioretention (See BMP T7.30: Biore- tention), with the exception that the compost may have up to 35% biosolids or manure.  l Sections 3 through 7 of Building Soil: Guidelines and Resources for Implementing Soil Quality and Depth BMP T5.13 in WDOE Stormwater Management Manual for Western Washington  (Stenn et al., 2016), provides useful guidance for implementing whichever option is chosen. It  includes guidance for pre-approved default strategies and guidance for custom strategies.  Check with your local jurisdiction concerning its acceptance of this guidance.  l The final composition and construction of the soil system will result in a natural selection or  favoring of certain plant species over time. For example, incorporation of topsoil may favor  grasses, while layering with mildly acidic, high-carbon amendments may favor more woody  vegetation.  l Allow sufficient time in scheduling for topsoil spreading prior to seeding, sodding, or planting.  l Take care when applying top soil to subsoils with contrasting textures. Sandy topsoil over  clayey subsoil is a particularly poor combination, as water creeps along the junction between  the soil layers and causes the topsoil to slough. If topsoil and subsoil are not properly bonded,  water will not infiltrate the soil profile evenly and it will be difficult to establish vegetation. The  best method to promote bonding is to actually work the topsoil into the layer below for a depth  of at least 6 inches.  l Field exploration of the site shall be made to determine if there is surface soil of sufficient  quantity and quality to justify stripping. Topsoil shall be friable and loamy (loam, sandy loam,  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 302 silt loam, sandy clay loam, and clay loam). Avoid areas of natural ground water recharge.  l Stripping shall be confined to the immediate construction area. A 4-inch to 6-inch stripping  depth is common, but depth may vary depending on the particular soil. All surface runoff con- trol structures shall be in place prior to stripping.  l Do not place topsoil while in a frozen or muddy condition, when the subgrade is excessively  wet, or when conditions exist that may otherwise be detrimental to proper grading or pro- posed sodding or seeding.  l In any areas requiring grading, remove and stockpile the duff layer and topsoil on site in a des- ignated, controlled area, not adjacent to public resources and critical areas. Reapply stock- piled topsoil to other portions of the site where feasible.  l Locate the topsoil stockpile so that it meets specifications and does not interfere with work on  the site. It may be possible to locate more than one pile in proximity to areas where topsoil will  be used.  l Stockpiling of topsoil shall occur in the following manner:  o Side slopes of the stockpile shall not exceed 2H:1V.  o Between October 1 and April 30:  n An interceptor dike with gravel outlet and silt fence shall surround all topsoil.  n Within 2 days complete erosion control seeding, or covering stockpiles with clear  plastic, or other mulching materials.  o Between May 1 and September 30:  n An interceptor dike with gravel outlet and silt fence shall surround all topsoil if the  stockpile will remain in place for a longer period of time than active construction  grading.  n Within 7 days complete erosion control seeding, or covering stockpiles with clear  plastic, or other mulching materials.  l When native topsoil is to be stockpiled and reused the following should apply to ensure that  the mycorrhizal bacterial, earthworms, and other beneficial organisms will not be destroyed:  o Re-install topsoil within 4 to 6 weeks.  o Do not allow the saturation of topsoil with water.  o Do not use plastic covering. Maintenance Standards  l Inspect stockpiles regularly, especially after large storm events. Stabilize any areas that have  eroded.  l Establish soil quality and depth toward the end of construction and once established, protect  from compaction, such as from large machinery use, and from erosion. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 303  l Plant and mulch soil after installation.  l Leave plant debris or its equivalent on the soil surface to replenish organic matter.  l Reduce and adjust, where possible, the use of irrigation, fertilizers, herbicides and pesticides,  rather than continuing to implement formerly established practices. BMP C126: Polyacrylamide (PAM) for Soil Erosion Protection Purpose Polyacrylamide (PAM) is used on construction sites to prevent soil erosion. Applying PAM to bare soil in advance of a rain event significantly reduces erosion and controls sed- iment in two ways. First, PAM increases the soil’s available pore volume, thus increasing infiltration  and reducing the quantity of stormwater runoff. Second, it increases flocculation of suspended  particles and aids in their deposition, thus reducing stormwater runoff turbidity and improving water  quality. Conditions of Use PAM shall not be directly applied to water or allowed to enter a water body. Stormwater runoff shall  pass through a sediment pond prior to discharging to surface waters. PAM can be applied to bare soil under the following conditions:  l During rough grading operations.  l In Staging areas.  l Balanced cut and fill earthwork.  l Haul roads prior to placement of crushed rock surfacing.  l Compacted soil roadbase.  l Stockpiles.  l After final grade and before paving or final seeding and planting.  l Pit sites.  l Sites having a winter shut down. In the case of winter shut down, or where soil will remain  unworked for several months, PAM should be used together with mulch. Design and Installation Specifications  l Do not use PAM on a slope that flows directly into a stream or wetland.  l Do not add PAM to water discharging from the site. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 304  l PAM designated for these uses should be "water soluble" or "linear" or "non-crosslinked".  Cross-linked or water absorbent PAM, polymerized in highly acidic (pH<2) conditions, are  used to maintain soil moisture content.  l The PAM anionic charge density may vary from 2-30 percent; a value of 18 percent is typical.  Studies conducted by the United States Department of Agriculture (USDA)/ARS demon- strated that soil stabilization was optimized by using very high molecular weight (12-15 mg/- mole), highly anionic (>20% hydrolysis) PAM.  l PAM tackifiers are available and being used in place of guar and alpha plantago. Typically,  PAM tackifiers should be used at a mixing rate of no more than 0.5-1 lb. per 1000 gallons of  water in a hydromulch machine. Some tackifier product instructions say to use at an applic- ation rate of 3 – 5 lbs per acre, which can be too much. In addition, pump problems can occur  at higher application rates due to increased viscosity. Maintenance Standards  l PAM may be reapplied on actively worked areas after a 48-hour period.  l Reapplication is not required unless PAM treated soil is disturbed or unless turbidity levels  show the need for an additional application. If PAM treated soil is left undisturbed, a reapplic- ation may be necessary after two months. More PAM applications may be required for steep  slopes, silty and clayey soils (USDA Classification Type "C" and "D" soils), long grades, and  high precipitation areas. When PAM is applied first to bare soil and then covered with straw, a  reapplication may not be necessary for several months.  l Loss of sediment and PAM may be a basis for penalties per RCW 90.48.080.  l PAM may affect the treatment efficiency of chitosan flocculent systems. BMP C130: Surface Roughening Purpose Surface roughening aids in the establishment of vegetative cover, reduces runoff velocity, increases  infiltration, and provides for sediment trapping through the provision of a rough soil surface. Hori- zontal depressions are created by operating a tiller or other suitable equipment on the contour or by  leaving slopes in a roughened condition by not fine grading them. Use this BMP in conjunction with other BMPs such as BMP C120: Temporary and Permanent Seed- ing, BMP C121: Mulching, or BMP C124:  Sodding.  Conditions for Use  l All slopes steeper than 3H:1V and greater than 5 vertical feet require surface roughening to a  depth of 2 to 4 inches prior to seeding.  l Areas that will not be stabilized immediately may be roughened to reduce runoff velocity until  seeding takes place. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 307  l Slopes with a stable rock face do not require roughening.  l Slopes where mowing is planned should not be excessively roughened. Design and Installation Specifications There are different methods for achieving a roughened soil surface on a slope, and the selection of  an appropriate method depends upon the type of slope. Roughening methods include stair-step  grading, grooving, contour furrows, and tracking. See Figure II-3.5: Surface Roughening by Track- ing and Contour Furrows. Factors to be considered in choosing a roughening method are slope  steepness, mowing requirements, and whether the slope is formed by cutting or filling.  l Disturbed areas that will not require mowing may be stair-step graded, grooved, or left rough  after filling.  l Stair-step grading is particularly appropriate in soils containing large amounts of soft rock.  Each "step" catches material that sloughs from above, and provides a level site where veget- ation can become established. Stairs should be wide enough to work with standard earth mov- ing equipment. Stair steps must be on contour or gullies will form on the slope.  l Areas that will be mowed (these areas should have slopes less steep than 3H:1V) may have  small furrows left by disking, harrowing, raking, or seed-planting machinery operated on the  contour.  l Graded areas with slopes steeper than 3H:1V but less than 2H:1V should be roughened  before seeding. This can be accomplished in a variety of ways, including "track walking," or  driving a crawler tractor up and down the slope, leaving a pattern of cleat imprints parallel to  slope contours.  l Tracking is done by operating equipment up and down the slope to leave horizontal depres- sions in the soil. Maintenance Standards  l Areas that are surface roughened should be seeded as quickly as possible.  l Regular inspections should be made of the area. If rills appear, they should be re-roughened  and re-seeded immediately. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 308 Figure II-3.5: Surface Roughening by Tracking and Contour Furrows 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 309 flow.  l Vertical spacing determined by the above methods may be increased as much as 0.5 feet or  10 percent, whichever is greater, to provide better alignment or location, to avoid obstacles, to  adjust for equipment size, or to reach a satisfactory outlet. The drainage area above the ter- race should not exceed the area that would be drained by a terrace with normal spacing.  l The terrace should have enough capacity to handle the peak runoff expected from a 2-year,  24-hour design storm without overtopping.  l The terrace cross-section should be proportioned to fit the land slope.   l The ridge height should include a reasonable settlement factor.   l The ridge should have a minimum top width of 3 feet at the design height.   l The minimum cross-sectional area of the terrace channel should be 8 square feet for land  slopes of 5 percent or less, 7 square feet for slopes from 5 to 8 percent, and 6 square feet for  slopes steeper than 8 percent. The terrace can be constructed wide enough to be maintained  using a small vehicle. Maintenance Standards Maintenance should be performed as needed. Terraces should be inspected regularly; at least once  per year, and after large storm events. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 311 Figure II-3.6: Gradient Terraces 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 312 BMP C140: Dust Control Purpose Dust control prevents wind transport of dust from disturbed soil surfaces onto roadways, drainage  ways, and surface waters. Conditions of Use Use dust control in areas (including roadways) subject to surface and air movement of dust where  on-site or off-site impacts to roadways, drainage ways, or surface waters are likely. Design and Installation Specifications  l Vegetate or mulch areas that will not receive vehicle traffic. In areas where planting, mulching,  or paving is impractical, apply gravel or landscaping rock.  l Limit dust generation by clearing only those areas where immediate activity will take place,  leaving the remaining area(s) in the original condition. Maintain the original ground cover as  long as practical.  l Construct natural or artificial windbreaks or windscreens. These may be designed as enclos- ures for small dust sources.  l Sprinkle the site with water until the surface is wet. Repeat as needed. To prevent carryout of  mud onto the street, refer to BMP C105:  Stabilized Construction Access and BMP C106:  Wheel Wash.  l Irrigation water can be used for dust control. Irrigation systems should be installed as a first  step on sites where dust control is a concern.  l Spray exposed soil areas with a dust palliative, following the manufacturer’s instructions and  cautions regarding handling and application. Used oil is prohibited from use as a dust sup- pressant. Local governments may approve other dust palliatives such as calcium chloride or  PAM.  l PAM (BMP C126:  Polyacrylamide (PAM) for Soil Erosion Protection) added to water at a rate  of 0.5 pounds per 1,000 gallons of water per acre and applied from a water truck is more effect- ive than water alone. This is due to increased infiltration of water into the soil and reduced  evaporation. In addition, small soil particles are bonded together and are not as easily trans- ported by wind. Adding PAM may reduce the quantity of water needed for dust control. Note  that the application rate specified here applies to this BMP, and is not the same application  rate that is specified in BMP C126:  Polyacrylamide (PAM) for Soil Erosion Protection, but the  downstream protections still apply. Refer to BMP C126:  Polyacrylamide (PAM) for Soil Erosion Protection for conditions of use.  PAM shall not be directly applied to water or allowed to enter a water body.  l Contact your local Air Pollution Control Authority for guidance and training on other dust con- trol measures. Compliance with the local Air Pollution Control Authority constitutes  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 313 compliance with this BMP.  l Use vacuum street sweepers.  l Remove mud and other dirt promptly so it does not dry and then turn into dust.  l Techniques that can be used for unpaved roads and lots include:  o Lower speed limits. High vehicle speed increases the amount of dust stirred up from  unpaved roads and lots.  o Upgrade the road surface strength by improving particle size, shape, and mineral types  that make up the surface and base materials.  o Add surface gravel to reduce the source of dust emission. Limit the amount of fine  particles (those smaller than .075 mm) to 10 to 20 percent.  o Use geotextile fabrics to increase the strength of new roads or roads undergoing recon- struction.  o Encourage the use of alternate, paved routes, if available.  o Apply chemical dust suppressants using the admix method, blending the product with  the top few inches of surface material. Suppressants may also be applied as surface  treatments.  o Limit dust-causing work on windy days.  o Pave unpaved permanent roads and other trafficked areas. Maintenance Standards Respray area as necessary to keep dust to a minimum. BMP C150: Materials on Hand Purpose Keep quantities of erosion prevention and sediment control materials on the project site at all times  to be used for regular maintenance and emergency situations such as unexpected heavy rains. Hav- ing these materials on-site reduces the time needed to replace existing or implement new BMPs  when inspections indicate that existing BMPs are not meeting the Construction SWPPP require- ments. In addition, contractors can save money by buying some materials in bulk and storing them at  their office or yard. Conditions of Use  l Construction projects of any size or type can benefit from having materials on hand. A small  commercial development project could have a roll of plastic and some gravel available for  immediate protection of bare soil and temporary berm construction. A large earthwork project,  such as highway construction, might have several tons of straw, several rolls of plastic, flexible  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 314 pipe, sandbags, geotextile fabric and steel “T” posts.  l Materials should be stockpiled and readily available before any site clearing, grubbing, or  earthwork begins. A large contractor or project proponent could keep a stockpile of materials  that are available for use on several projects.  l If storage space at the project site is at a premium, the contractor could maintain the materials  at their office or yard. The office or yard must be less than an hour from the project site. Design and Installation Specifications Depending on project type, size, complexity, and length, materials and quantities will vary. A good  minimum list of items that will cover numerous situations includes:  l Clear Plastic, 6 mil  l Drainpipe, 6 or 8 inch diameter  l Sandbags, filled  l Straw Bales for mulching  l Quarry Spalls  l Washed Gravel  l Geotextile Fabric  l Catch Basin Inserts  l Steel "T" Posts  l Silt fence material  l Straw Wattles Maintenance Standards  l All materials with the exception of the quarry spalls, steel “T” posts, and gravel should be kept  covered and out of both sun and rain.  l Re-stock materials as needed. BMP C151: Concrete Handling Purpose Concrete work can generate process water and slurry that contain fine particles and high pH, both of  which can violate water quality standards in the receiving water. Concrete spillage or concrete dis- charge to waters of the State is prohibited. Use this BMP to minimize and eliminate concrete, con- crete process water, and concrete slurry from entering waters of the State. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 315 Conditions of Use Any time concrete is used, utilize these management practices. Concrete construction project com- ponents include, but are not limited to:  l Curbs  l Sidewalks  l Roads  l Bridges  l Foundations  l Floors  l Runways Disposal options for concrete, in order of preference are:  1. Off-site disposal  2. Concrete wash-out areas (see BMP C154: Concrete Washout Area)  3. De minimus washout to formed areas awaiting concrete Design and Installation Specifications  l Wash concrete truck drums at an approved off-site location or in designated concrete  washout areas only. Do not wash out  concrete trucks onto the ground (including formed areas  awaiting concrete), or into storm drains, open ditches, streets, or streams. Refer to BMP  C154: Concrete Washout Area for information on concrete washout areas.  o Return unused concrete remaining in the truck and pump to the originating batch plant  for recycling. Do not dump excess concrete on site, except in designated concrete  washout areas as allowed in BMP C154: Concrete Washout Area.  l Wash small concrete handling equipment (e.g. hand tools, screeds, shovels, rakes, floats,  trowels, and wheelbarrows) into designated concrete washout areas or into formed areas  awaiting concrete pour.  l At no time shall concrete be washed off into the footprint of an area where an infiltration fea- ture will be installed.  l Wash equipment difficult to move, such as concrete paving machines, in areas that do not dir- ectly drain to natural or constructed stormwater conveyance or potential infiltration areas.  l Do not allow washwater from areas, such as concrete aggregate driveways, to drain directly  (without detention or treatment) to natural or constructed stormwater conveyances.  l Contain washwater and leftover product in a lined container when no  designated concrete  washout areas (or formed areas, allowed as described above) are available. Dispose of con- tained concrete and concrete washwater (process water) properly. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 316  l Always use forms or solid barriers for concrete pours, such as pilings, within 15-feet of surface  waters.  l Refer to BMP C252:  Treating and Disposing of High pH Water for pH adjustment require- ments.  l Refer to the Construction Stormwater General Permit (CSWGP) for pH monitoring require- ments if the project involves one of the following activities:  o Significant concrete work (as defined in the CSWGP).  o The use of soils amended with (but not limited to) Portland cement-treated base,  cement kiln dust or fly ash.  o Discharging stormwater to segments of water bodies on the 303(d) list (Category 5) for  high pH. Maintenance Standards Check containers for holes in the liner daily during concrete pours and repair the same day. BMP C152: Sawcutting and Surfacing Pollution Prevention Purpose Sawcutting and surfacing operations generate slurry and process water that contains fine particles  and high pH (concrete cutting), both of which can violate the water quality standards in the receiving  water. Concrete spillage or concrete discharge to waters of the State is prohibited. Use this BMP to  minimize and eliminate process water and slurry created through sawcutting or surfacing from enter- ing waters of the State. Conditions of Use Utilize these management practices anytime sawcutting or surfacing operations take place. Saw- cutting and surfacing operations include, but are not limited to:  l Sawing  l Coring  l Grinding  l Roughening  l Hydro-demolition  l Bridge and road surfacing 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 317 Design and Installation Specifications  l Vacuum slurry and cuttings during cutting and surfacing operations.  l Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight.  l Slurry and cuttings shall not drain to any natural or constructed drainage conveyance includ- ing stormwater systems. This may require temporarily blocking catch basins.  l Dispose of collected slurry and cuttings in a manner that does not violate ground water or sur- face water quality standards.  l Do not allow process water generated during hydro-demolition, surface roughening or similar  operations to drain to any natural or constructed drainage conveyance including stormwater  systems. Dispose of process water in a manner that does not violate ground water or surface  water quality standards.  l Handle and dispose of cleaning waste material and demolition debris in a manner that does  not cause contamination of water. Dispose of sweeping material from a pick-up sweeper at an  appropriate disposal site. Maintenance Standards Continually monitor operations to determine whether slurry, cuttings, or process water could enter  waters of the state. If inspections show that a violation of water quality standards could occur, stop  operations and immediately implement preventive measures such as berms, barriers, secondary  containment, and/or vacuum trucks. BMP C153: Material Delivery, Storage, and Containment Purpose Prevent, reduce, or eliminate the discharge of pollutants to the stormwater system or watercourses  from material delivery and storage. Minimize the storage of hazardous materials on-site, store mater- ials in a designated area, and install secondary containment. Conditions of Use Use at construction sites with delivery and storage of the following materials:  l Petroleum products such as fuel, oil and grease  l Soil stabilizers and binders (e.g., Polyacrylamide)  l Fertilizers, pesticides and herbicides  l Detergents  l Asphalt and concrete compounds 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 318  l Hazardous chemicals such as acids, lime, adhesives, paints, solvents, and curing compounds  l Any other material that may be detrimental if released to the environment Design and Installation Specifications  l The temporary storage area should be located away from vehicular traffic, near the con- struction entrance(s), and away from waterways or storm drains.  l Safety Data Sheets (SDS) should be supplied for all materials stored. Chemicals should be  kept in their original labeled containers.  l Hazardous material storage on-site should be minimized.  l Hazardous materials should be handled as infrequently as possible.  l During the wet weather season (Oct 1 – April 30), consider storing materials in a covered  area.  l Materials should be stored in secondary containments, such as an earthen dike, horse trough,  or even a children’s wading pool for non-reactive materials such as detergents, oil, grease,  and paints. Small amounts of material may be secondarily contained in “bus boy” trays or con- crete mixing trays.  l Do not store chemicals, drums, or bagged materials directly on the ground. Place these items  on a pallet and, when possible, within secondary containment.  l If drums must be kept uncovered, store them at a slight angle to reduce ponding of rainwater  on the lids to reduce corrosion. Domed plastic covers are inexpensive and snap to the top of  drums, preventing water from collecting.  l Liquids, petroleum products, and substances listed in 40 CFR Parts 110, 117, or 302 shall be  stored in approved containers and drums and shall not be overfilled. Containers and drums  shall be stored in temporary secondary containment facilities.  l Temporary secondary containment facilities shall provide for a spill containment volume able  to contain 10% of the total enclosed container volume of all containers, or 110% of the capa- city of the largest container within its boundary, whichever is greater.  l Secondary containment facilities shall be impervious to the materials stored therein for a min- imum contact time of 72 hours.  l Sufficient separation should be provided between stored containers to allow for spill cleanup  and emergency response access.  l During the wet weather season (Oct 1 – April 30), each secondary containment facility shall  be covered during non-working days, prior to and during rain events.  l Keep material storage areas clean, organized and equipped with an ample supply of appro- priate spill clean-up material (spill kit).  l The spill kit should include, at a minimum: 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 319  o 1-Water Resistant Nylon Bag  o 3-Oil Absorbent Socks 3”x 4’  o 2-Oil Absorbent Socks 3”x 10’  o 12-Oil Absorbent Pads 17”x19”  o 1-Pair Splash Resistant Goggles  o 3-Pair Nitrile Gloves  o 10-Disposable Bags with Ties  o Instructions Maintenance Standards  l Secondary containment facilities shall be maintained free of accumulated rainwater and spills.  In the event of spills or leaks, accumulated rainwater and spills shall be collected and placed  into drums. These liquids shall be handled as hazardous waste unless testing determines  them to be non-hazardous.  l Re-stock spill kit materials as needed. BMP C154: Concrete Washout Area Purpose Prevent or reduce the discharge of pollutants from concrete waste to stormwater by conducting  washout off-site, or performing on-site washout in a designated area. Conditions of Use Concrete washout areas are implemented on construction projects where:  l Concrete is used as a construction material  l It is not possible to dispose of all concrete wastewater and washout off-site (ready mix plant,  etc.).  l Concrete truck drums are washed on-site. Note that auxiliary concrete truck components (e.g. chutes and hoses) and small concrete  handling equipment (e.g. hand tools, screeds, shovels, rakes, floats, trowels, and wheel- barrows) may be washed into formed areas awaiting concrete pour. At no time shall concrete be washed off into the footprint of an area where an infiltration feature will  be installed. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 320 Design and Installation Specifications Implementation  l Perform washout of concrete truck drums at an approved off-site location or in designated con- crete washout areas only.  l Do not wash out concrete onto non-formed areas, or into storm drains, open ditches, streets,  or streams.  l Wash equipment difficult to move, such as concrete paving machines, in areas that do not dir- ectly drain to natural or constructed stormwater conveyance or potential infiltration areas.  l Do not allow excess concrete to be dumped on-site, except in designated concrete washout  areas as allowed above.  l Concrete washout areas may be prefabricated concrete washout containers, or self-installed  structures (above-grade or below-grade).  l Prefabricated containers are most resistant to damage and protect against spills and leaks.  Companies may offer delivery service and provide regular maintenance and disposal of solid  and liquid waste.  l If self-installed concrete washout areas are used, below-grade structures are preferred over  above-grade structures because they are less prone to spills and leaks.  l Self-installed above-grade structures should only be used if excavation is not practical.  l Concrete washout areas shall be constructed and maintained in sufficient quantity and size to  contain all liquid and concrete waste generated by washout operations. Education  l Discuss the concrete management techniques described in this BMP with the ready-mix con- crete supplier before any deliveries are made.  l Educate employees and subcontractors on the concrete waste management techniques  described in this BMP.  l Arrange for the contractor’s superintendent or Certified Erosion and Sediment Control Lead  (CESCL) to oversee and enforce concrete waste management procedures.  l A sign should be installed adjacent to each concrete washout area to inform concrete equip- ment operators to utilize the proper facilities. Contracts Incorporate requirements for concrete waste management into concrete supplier and subcontractor  agreements. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 321 Location and Placement  l Locate concrete washout areas at least 50 feet from sensitive areas such as storm drains,  open ditches, water bodies, or wetlands.  l Allow convenient access to the concrete washout area for concrete trucks, preferably near the  area where the concrete is being poured.  l If trucks need to leave a paved area to access the concrete washout area, prevent track-out  with a pad of rock or quarry spalls (see BMP C105:  Stabilized Construction Access). These  areas should be far enough away from other construction traffic to reduce the likelihood of acci- dental damage and spills.  l The number of concrete washout areas you install should depend on the expected demand  for storage capacity.  l On large sites with extensive concrete work, concrete washout areas should be placed in mul- tiple locations for ease of use by concrete truck drivers. Concrete Truck Washout Procedures  l Washout of concrete truck drums shall be performed in designated concrete washout areas  only.  l Concrete washout from concrete pumper bins can be washed into concrete pumper trucks  and discharged into designated concrete washout areas or properly disposed of off-site. Concrete Washout Area Installation  l Concrete washout areas should be constructed as shown in the figures below, with a recom- mended minimum length and minimum width of 10 ft, but with sufficient quantity and volume to  contain all liquid and concrete waste generated by washout operations.  l Plastic lining material should be a minimum of 10 mil polyethylene sheeting and should be free  of holes, tears, or other defects that compromise the impermeability of the material.  l Lath and flagging should be commercial type.  l Liner seams shall be installed in accordance with manufacturers’ recommendations.  l Soil base shall be prepared free of rocks or other debris that may cause tears or holes in the  plastic lining material. Maintenance Standards Inspection and Maintenance  l Inspect and verify that concrete washout areas are in place prior to the commencement of con- crete work.  l Once concrete wastes are washed into the designated washout area and allowed to harden,  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 322 the concrete should be broken up, removed, and disposed of per applicable solid waste reg- ulations. Dispose of hardened concrete on a regular basis.  l During periods of concrete work, inspect the concrete washout areas daily to verify continued  performance.  o Check overall condition and performance.  o Check remaining capacity (% full).  o If using self-installed concrete washout areas, verify plastic liners are intact and side- walls are not damaged.  o If using prefabricated containers, check for leaks.  l Maintain the concrete washout areas to provide adequate holding capacity with a minimum  freeboard of 12 inches.  l Concrete washout areas must be cleaned, or new concrete washout areas must be con- structed and ready for use once the concrete washout area is 75% full.  l If the concrete washout area is nearing capacity, vacuum and dispose of the waste material in  an approved manner.  l Do not discharge liquid or slurry to waterways, storm drains or directly onto ground.  l Do not discharge to the sanitary sewer without local approval.  l Place a secure, non-collapsing, non-water collecting cover over the concrete washout  area prior to predicted wet weather to prevent accumulation and overflow of pre- cipitation.  l Remove and dispose of hardened concrete and return the structure to a functional con- dition. Concrete may be reused on-site or hauled away for disposal or recycling.  l When you remove materials from a self-installed concrete washout area, build a new struc- ture; or, if the previous structure is still intact, inspect for signs of weakening or damage, and  make any necessary repairs. Re-line the structure with new plastic after each cleaning. Removal of Concrete Washout Areas  l When concrete washout areas are no longer required for the work, the hardened concrete,  slurries and liquids shall be removed and properly disposed of.  l Materials used to construct concrete washout areas shall be removed from the site of the work  and disposed of or recycled.  l Holes, depressions or other ground disturbance caused by the removal of the concrete  washout areas shall be backfilled, repaired, and stabilized to prevent erosion. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 323 Figure II-3.7: Concrete Washout Area with Wood Planks 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 324 Figure II-3.8: Concrete Washout Area with Straw Bales 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 325 Figure II-3.9: Prefabricated Concrete Washout Container w/Ramp 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 326 Conditions of Use The construction sequence schedule is an orderly listing of all major land-disturbing activities  together with the necessary erosion and sedimentation control measures planned for the project.  This type of schedule guides the contractor on work to be done before other work is started so that  serious erosion and sedimentation problems can be avoided. Following a specified work schedule that coordinates the timing of land-disturbing activities and the  installation of control measures is perhaps the most cost-effective way of controlling erosion during  construction. The removal of ground cover leaves a site vulnerable to erosion. Construction sequen- cing that limits land clearing, provides timely installation of erosion and sedimentation controls, and  restores protective cover quickly can significantly reduce the erosion potential of a site. Design Considerations  l Minimize construction during rainy periods.  l Schedule projects to disturb only small portions of the site at any one time. Complete grading  as soon as possible. Immediately stabilize the disturbed portion before grading the next por- tion. Practice staged seeding in order to revegetate cut and fill slopes as the work progresses. II-3.3 Construction Runoff BMPs BMP C200: Interceptor Dike and Swale Purpose Provide a dike of compacted soil or a swale at the top or base of a disturbed slope or along the peri- meter of a disturbed construction area to convey stormwater. Use the dike and/or swale to intercept  the runoff from unprotected areas and direct it to areas where erosion can be controlled. This can  prevent storm runoff from entering the work area or sediment-laden runoff from leaving the con- struction site. Conditions of Use Use an interceptor dike or swale where runoff from an exposed site or disturbed slope must be con- veyed to an erosion control BMP which can safely convey the stormwater.  l Locate upslope of a construction site to prevent runoff from entering the disturbed area.  l When placed horizontally across a disturbed slope, it reduces the amount and velocity of run- off flowing down the slope.  l Locate downslope to collect runoff from a disturbed area and direct it to a sediment  BMP (e.g.  BMP C240:  Sediment Trap or BMP C241:  Sediment Pond (Temporary)). 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 329 Design and Installation Specifications  l Dike and/or swale and channel must be stabilized with temporary or permanent vegetation or  other channel protection during construction.  l Steep grades require channel protection and check dams.  l Review construction for areas where overtopping may occur.  l Can be used at the top of new fill before vegetation is established.  l May be used as a permanent diversion channel to carry the runoff.  l Contributing area for an individual dike or swale should be one acre or less.  l Design the dike and/or swale to contain flows calculated by one of the following methods:  o 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 for the worst-case  land cover condition. OR  o Continuous Simulation Method: The 10-year peak flow rate, as determined by an  approved continuous runoff model with a 15-minute time step for the worst-case land  cover condition. Worst-case land cover conditions (i.e., producing the most runoff) should be used for analysis  (in most cases, this would be the land cover conditions just prior to final landscaping). Interceptor Dikes Interceptor dikes shall meet the following criteria:  l Top Width: 2 feet minimum.  l Height:  1.5 feet minimum on berm.  l Side Slope: 2H:1V or flatter.  l Grade: Depends on topography, however, dike system minimum is 0.5%, and maximum is  1%.  l Compaction: Minimum of 90 percent ASTM D698 standard proctor.  l Stabilization: Depends on velocity and reach. Inspect regularly to ensure stability.  l Ground Slopes <5%: Seed and mulch applied within 5 days of dike construction (see BMP  C121: Mulching).  l Ground Slopes 5 - 40%: Dependent on runoff velocities and dike materials. Stabilization  should be done immediately using either sod or riprap, or other measures to avoid erosion.  l The upslope side of the dike shall provide positive drainage to the dike outlet. No erosion shall  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 330 occur at the outlet. Provide energy dissipation measures as necessary. Sediment-laden runoff  must be released through a sediment trapping facility.  l Minimize construction traffic over temporary dikes. Use temporary cross culverts for channel  crossing.  l See Table II-3.8: Horizontal Spacing of Interceptor Dikes Along Ground Slope for recom- mended horizontal spacing between dikes. Average Slope Slope Percent Flowpath Length 20H:1V or less 3-5%300  feet (10 to 20)H:1V 5-10%200  feet (4 to 10)H:1V 10-25%100  feet (2 to 4)H:1V 25-50%50  feet Table II-3.8: Horizontal Spacing of Interceptor Dikes Along Ground Slope Interceptor Swales Interceptor swales shall meet the following criteria:  l Bottom Width: 2 feet minimum; the cross-section bottom shall be level.  l Depth: 1-foot minimum.  l Side Slope: 2H:1V or flatter.  l Grade: Maximum 5 percent, with positive drainage to a suitable outlet (such as BMP C241:   Sediment Pond (Temporary)).  l Stabilization: Seed as per BMP C120: Temporary and Permanent Seeding, or BMP C202:   Riprap Channel Lining, 12 inches thick riprap pressed into the bank and extending at least 8  inches vertical from the bottom. Maintenance Standards  l Inspect diversion dikes and interceptor swales once a week and after every rainfall. Imme- diately remove sediment from the flow area.  l Damage caused by construction traffic or other activity must be repaired before the end of  each working day.  l Check outlets and make timely repairs as needed to avoid gully formation. When the area  below the temporary diversion dike is permanently stabilized, remove the dike and fill and sta- bilize the channel to blend with the natural surface. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 331 BMP C207: Check Dams Purpose Construction of check dams across a swale or ditch reduces the velocity of concentrated flow and dis- sipates energy at the check dam. Conditions of Use Use check dams where temporary or permanent channels are not yet vegetated, channel lining is  infeasible, and/or velocity checks are required.  l Check dams may not be placed in streams unless approved by the State Department of Fish  and Wildlife.   l Check dams may not be placed in wetlands without approval from a permitting agency.  l Do not place check dams below the expected backwater from any salmonid bearing water  between October 1 and May 31 to ensure that there is no loss of high flow refuge habitat for  overwintering juvenile salmonids and emergent salmonid fry. Design and Installation Specifications  l Construct rock check dams from appropriately sized rock. The rock used must be large  enough to stay in place given the expected design flow through the channel. The rock must be  placed by hand or by mechanical means (do not dump the rock to form the dam) to achieve  complete coverage of the ditch or swale and to ensure that the center of the dam is lower than  the edges.  l Check dams may also be constructed of either rock or pea-gravel filled bags. Numerous new  products are also available for this purpose. They tend to be re-usable, quick and easy to  install, effective, and cost efficient.  l Place check dams perpendicular to the flow of water.  l The check dam should form a triangle when viewed from the side. This prevents undercutting  as water flows over the face of the check dam rather than falling directly onto the ditch bottom.  l Before installing check dams, impound and bypass upstream water flow away from the work  area. Options for bypassing include pumps, siphons, or temporary channels.  l Check dams combined with sumps work more effectively at slowing flow and retaining sed- iment than a check dam alone. A deep sump should be provided immediately upstream of the  check dam.  l In some cases, if carefully located and designed, check dams can remain as permanent install- ations with very minor regrading. They may be left as either spillways, in which case accu- mulated sediment would be graded and seeded, or as check dams to prevent further  sediment from leaving the site.  l The maximum spacing between check dams shall be such that the downstream toe of the  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 351 upstream dam is at the same elevation as the top of the downstream dam.  l Keep the maximum height at 2 feet at the center of the check dam.  l Keep the center of the check dam at least 12 inches lower than the outer edges at natural  ground elevation.  l Keep the side slopes of the check dam at 2H:1V or flatter.  l Key the stone into the ditch banks and extend it beyond the abutments a minimum of 18  inches to avoid washouts from overflow around the dam.  l Use filter fabric foundation under a rock or sand bag check dam. If a blanket ditch liner is used,  filter fabric is not necessary. A piece of organic or synthetic blanket cut to fit will also work for  this purpose.  l In the case of grass-lined ditches and swales, all check dams and accumulated sediment shall  be removed when the grass has matured sufficiently to protect the ditch or swale - unless the  slope of the swale is greater than 4 percent. The area beneath the check dams shall be  seeded and mulched immediately after dam removal.  l Ensure that channel appurtenances, such as culvert entrances below check dams, are not  subject to damage or blockage from displaced stones.   l See Figure II-3.16: Rock Check Dam. Maintenance Standards Check dams shall be monitored for performance and sediment accumulation during and after each  rainfall that produces runoff. Sediment shall be removed when it reaches one half the sump depth.  l Anticipate submergence and deposition above the check dam and erosion from high flows  around the edges of the dam.  l If significant erosion occurs between dams, install a protective riprap liner in that portion of the  channel. See BMP C202:  Riprap Channel Lining. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 352 Figure II-3.16: Rock Check Dam 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 353 and staples.  o In the case of grass-lined ditches and swales, check dams and accumulated sediment  shall be removed when the grass has matured sufficiently to protect the ditch or swale  unless the slope of the swale is greater than 4 percent. The area beneath the check  dams shall be seeded and mulched immediately after dam removal. Maintenance Standards  l Inspect TSDs for performance and sediment accumulation during and after each rainfall that  produces runoff. Remove sediment when it reaches one half the height of the TSD.  l Anticipate submergence and deposition above the TSD and erosion from high flows around  the edges of the TSD. Immediately repair any damage or any undercutting of the TSD. BMP C209: Outlet Protection Purpose Outlet protection prevents scour at conveyance outlets and minimizes the potential for downstream  erosion by reducing the velocity of concentrated stormwater flows. Conditions of Use Use outlet protection at the outlets of all ponds, pipes, ditches, or other conveyances  that discharge  to a natural or manmade drainage feature such as a stream, wetland, lake, or ditch. Design and Installation Specifications  l The receiving channel at the outlet of a pipe shall be protected from erosion by lining a min- imum of 6 feet downstream and extending up the channel sides a minimum of 1–foot above  the maximum tailwater elevation, or 1-foot above the crown, whichever is higher. For pipes lar- ger than 18 inches in diameter, the outlet protection lining of the channel shall be four times  the diameter of the outlet pipe.  l Standard wingwalls, tapered outlets, and paved channels should also be considered when  appropriate for permanent culvert outlet protection (WSDOT, 2015).  l BMP C122:  Nets and Blankets or BMP C202:  Riprap Channel Lining provide suitable options  for lining materials.  l With low flows, BMP C201: Grass-Lined Channels can be an effective alternative for lining  material.  l The following guidelines shall be used for outlet protection with riprap:  o If the discharge velocity at the outlet is less than 5 fps, use 2-inch to 8-inch riprap. Min- imum thickness is 1-foot.  o For 5 to 10 fps discharge velocity at the outlet, use 24-inch to 48-inch riprap. Minimum  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 355 thickness is 2 feet.  o For outlets at the base of steep slope pipes (pipe slope greater than 10 percent), use an  engineered energy dissipator.  o Filter fabric or erosion control blankets should always be used under riprap to prevent  scour and channel erosion. See BMP C122:  Nets and Blankets.  l Bank stabilization, bioengineering, and habitat features may be required for disturbed areas.  This work may require a Hydraulic Project Approval (HPA) from the Washington State Depart- ment of Fish and Wildlife. See I-2.11 Hydraulic Project Approvals. Maintenance Standards  l Inspect and repair as needed.  l Add rock as needed to maintain the intended function.  l Clean energy dissipator if sediment builds up. BMP C220: Inlet Protection Purpose Inlet protection prevents coarse sediment from entering drainage systems prior to permanent sta- bilization of the disturbed area. Conditions of Use Use inlet protection at inlets that are operational before permanent stabilization of the disturbed  areas that contribute runoff to the inlet. Provide protection for all storm drain inlets downslope and  within 500 feet of a disturbed or construction area, unless  those inlets are preceded by a sediment  trapping BMP. Also consider inlet protection for lawn and yard drains on new home construction. These small and  numerous drains coupled with lack of gutters can add significant amounts of sediment into the roof  drain system. If possible, delay installing lawn and yard drains until just before landscaping, or cap  these drains to prevent sediment from entering the system until completion of landscaping. Provide  18-inches of sod around each finished lawn and yard drain. Table II-3.10: Storm Drain Inlet Protection lists several options for inlet protection. All of the methods  for inlet protection tend to plug and require a high frequency of maintenance. Limit contributing drain- age areas for an individual inlet to one acre or less. If possible, provide emergency overflows with  additional end-of-pipe treatment where stormwater ponding would cause a hazard. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 356 Type of Inlet Pro- tection Emergency Overflow Applicable for Paved/ Earthen Sur- faces Conditions of Use Drop Inlet Protection Excavated  drop  inlet protection Yes, temporary  flooding may   occur Earthen Applicable for heavy flows. Easy   to maintain. Large area requirement:   30'x30'/acre Block  and gravel  drop inlet pro- tection Yes Paved or Earthen Applicable for heavy  concentrated flows.  Will not pond. Gravel and wire  drop inlet pro- tection No Paved or Earthen Applicable for  heavy concentrated flows.  Will pond. Can withstand traffic. Catch  basin filters Yes Paved or Earthen Frequent maintenance  required. Curb Inlet Protection Curb  inlet pro- tection with  wooden weir Small capacity  overflow Paved Used for sturdy, more compact  install- ation. Block and gravel  curb inlet pro- tection Yes Paved Sturdy, but  limited filtration. Culvert Inlet Protection Culvert  inlet sed- iment trap N/A N/A 18 month expected life. Table II-3.10: Storm Drain Inlet Protection Design and Installation Specifications Excavated Drop Inlet Protection Excavated drop inlet protection consists of an excavated impoundment around the storm drain inlet.  Sediment settles out of the stormwater prior to entering the storm drain. Design and installation spe- cifications for excavated drop inlet protection include:  l Provide a depth of 1-2 ft as measured from the crest of the inlet structure.  l Slope sides of excavation should be no steeper than 2H:1V.  l Minimum volume of excavation is 35 cubic yards.  l Shape the excavation to fit the site, with the longest dimension oriented toward the longest  inflow area.  l Install provisions for draining to prevent standing water.  l Clear the area of all debris. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 357  l Grade the approach to the inlet uniformly.  l Drill weep holes into the side of the inlet.  l Protect weep holes with screen wire and washed aggregate.  l Seal weep holes when removing structure and stabilizing area.  l Build a temporary dike, if necessary, to the down slope side of the structure to prevent bypass  flow. Block and Gravel Filter A block and gravel filter is a barrier formed around the inlet with standard concrete blocks and gravel.  See Figure II-3.17: Block and Gravel Filter. Design and installation specifications for block gravel fil- ters include:  l Provide a height of 1 to 2 feet above the inlet.  l Recess the first row of blocks 2-inches into the ground for stability.  l Support subsequent courses by placing a pressure treated wood 2x4 through the block open- ing.  l Do not use mortar.  l Lay some blocks in the bottom row on their side to allow for dewatering the pool.  l Place hardware cloth or comparable wire mesh with ½-inch openings over all block openings.  l Place gravel to just below the top of blocks on slopes of 2H:1V or flatter.  l An alternative design is a gravel berm surrounding the inlet, as follows:  o Provide a slope of 3H:1V on the upstream side of the berm.  o Provide a slope of 2H:1V on the downstream side of the berm.  o Provide a 1-foot wide level stone area between the gravel berm and the inlet.  o Use stones 3 inches in diameter or larger on the upstream slope of the berm.  o Use gravel ½- to ¾-inch at a minimum thickness of 1-foot on the downstream slope of  the berm. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 358 Figure II-3.17: Block and Gravel Filter   2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 359 Gravel and Wire Mesh Filter Gravel and wire mesh filters are gravel barriers placed over the top of the inlet. This method does not  provide an overflow. Design and installation specifications for gravel and wire mesh filters include:  l Use a hardware cloth or comparable wire mesh with ½-inch openings.  o Place wire mesh over the drop inlet so that the wire extends a minimum of 1-foot bey- ond each side of the inlet structure.  o Overlap the strips if more than one strip of mesh is necessary.  l Place coarse aggregate over the wire mesh.  o Provide at least a 12-inch depth of aggregate over the entire inlet opening and extend at  least 18-inches on all sides. Catch Basin Filters Catch  basin filters are designed by manufacturers for construction sites. The limited sediment stor- age capacity increases the amount of inspection and maintenance required, which may be daily for  heavy sediment loads. To reduce maintenance requirements, combine a catch  basin filter with  another type of inlet protection. This type of inlet protection provides flow bypass without overflow  and therefore may be a better method for inlets located along active rights-of-way. Design and install- ation specifications for catch basin filters include:  l Provides 5 cubic feet of storage.  l Requires dewatering provisions.  l Provides a high-flow bypass that will not clog under normal use at a construction site.  l Insert the catch  basin filter in the catch  basin just below the grating. Curb Inlet Protection with Wooden Weir Curb inlet protection with wooden weir is an option that consists of a barrier formed around a curb  inlet with a wooden frame and gravel. Design and installation specifications for curb inlet protection  with wooden weirs include:  l Use wire mesh with ½-inch openings.  l Use extra strength filter cloth.  l Construct a frame.  l Attach the wire and filter fabric to the frame.  l Pile coarse washed aggregate against the wire and fabric.  l Place weight on the frame anchors. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 360 Block and Gravel Curb Inlet Protection Block and gravel curb inlet protection is a barrier formed around a curb inlet with concrete blocks and  gravel. See Figure II-3.18: Block and Gravel Curb Inlet Protection. Design and installation spe- cifications for block and gravel curb inlet protection include:  l Use wire mesh with ½-inch openings.  l Place two concrete blocks on their sides abutting the curb at either side of the inlet opening.  These are spacer blocks.  l Place a 2x4 stud through the outer holes of each spacer block to align the front blocks.  l Place blocks on their sides across the front of the inlet and abutting the spacer blocks.  l Place wire mesh over the outside vertical face.  l Pile coarse aggregate against the wire to the top of the barrier. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 361 Figure II-3.18: Block and Gravel Curb Inlet Protection   2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 362 Curb and Gutter Sediment Barrier Curb and gutter sediment barrier is a sandbag or rock berm (riprap and aggregate) 3 feet high and 3  feet wide in a horseshoe shape. See Figure II-3.19: Curb and Gutter Barrier. Design and installation  specifications for curb and gutter sediment barrier include:  l Construct a horseshoe shaped berm, faced with coarse aggregate if using riprap, 3 feet high  and 3 feet wide, at least 2 feet from the inlet.  l Construct a horseshoe shaped sedimentation trap on the upstream side of the berm. Size the  trap to sediment trap standards for protecting a culvert inlet. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 363 Figure II-3.19: Curb and Gutter Barrier 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 364 Maintenance Standards  l Inspect all forms of inlet protection frequently, especially after storm events. Clean and  replace clogged catch basin filters. For rock and gravel filters, pull away the rocks from the  inlet and clean or replace. An alternative approach would be to use the clogged rock as fill and  put fresh rock around the inlet.  l Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly  over the surrounding land area or stockpile and stabilize as appropriate. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C231: Brush Barrier Purpose The purpose of brush barriers is to reduce the transport of coarse sediment from a construction site  by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland  flow. Conditions of Use  l Brush barriers may be used downslope of disturbed areas that are less than one-quarter acre.  l Brush barriers are not intended to treat concentrated flows, nor are they intended to treat sub- stantial amounts of overland flow. Any concentrated flows must be directed to a sediment trap- ping BMP. The only circumstance in which overland flow can be treated solely by a brush  barrier, rather than by a sediment trapping BMP, is when the area draining to the barrier is  small.  l Brush barriers should only be installed on contours. Design and Installation Specifications  l Height: 2 feet (minimum) to 5 feet (maximum).  l Width: 5 feet at base (minimum) to 15 feet (maximum).  l Filter fabric (geotextile) may be anchored over the brush berm to enhance the filtration ability  of the barrier. Ten-ounce burlap is an adequate alternative to filter fabric. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 365 BMP C233: Silt Fence Purpose Silt fence reduces the transport of coarse sediment from a construction site by providing a temporary  physical barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use Silt fence may be used downslope of all disturbed areas.  l Silt fence shall prevent sediment carried by runoff from going beneath, through, or over the  top of the silt fence, but shall allow the water to pass through the fence.  l Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial  amounts of overland flow. Convey any concentrated flows through the drainage system to a  sediment trapping BMP.  l Do not construct silt fences in streams or use in V-shaped ditches. Silt fences do not provide  an adequate method of silt control for anything deeper than sheet or overland flow. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 370 Figure II-3.22: Silt Fence 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 371 Design and Installation Specifications  l Use in combination with other construction stormwater BMPs.  l Maximum slope steepness (perpendicular to the silt fence line) 1H:1V.  l Maximum sheet or overland flow path length to the silt fence of 100 feet.  l Do not allow flows greater than 0.5 cfs.  l Use geotextile fabric that meets the following standards. All geotextile properties listed below  are minimum average roll values (i.e., the test result for any sampled roll in a lot shall meet or  exceed the values shown in Table II-3.11: Geotextile Fabric Standards for Silt Fence): Geotextile Property Minimum Average Roll Value Polymeric  Mesh AOS  (ASTM D4751) 0.60 mm maximum for slit film  woven (#30 sieve).  0.30 mm  maximum for all other geotextile types (#50 sieve).  0.15 mm minimum for all fabric types (#100 sieve). Water  Permittivity  (ASTM D4491) 0.02 sec-1 minimum Grab  Tensile Strength  (ASTM D4632) 180 lbs. Minimum for extra  strength fabric.  100 lbs  minimum for standard strength fabric. Grab Tensile Strength  (ASTM D4632) 30% maximum Ultraviolet  Resistance  (ASTM D4355) 70%  minimum Table II-3.11: Geotextile Fabric Standards for Silt Fence  l Support standard strength geotextiles with wire mesh, chicken wire, 2-inch x 2-inch wire,  safety fence, or jute mesh to increase the strength of the geotextile. Silt fence materials are  available that have synthetic mesh backing attached.  l Silt fence material shall contain ultraviolet ray inhibitors and stabilizers to provide a minimum  of six months of expected usable construction life at a temperature range of 0°F to 120°F.  l One-hundred percent biodegradable silt fence is available that is strong, long lasting, and can  be left in place after the project is completed, if permitted by the local jurisdiction.  l Refer to Figure II-3.22: Silt Fence for standard silt fence details. Include the following Stand- ard Notes for silt fence on construction plans and specifications:  1. The Contractor shall install and maintain temporary silt fences at the locations shown in  the Plans.  2. Construct silt fences in areas of clearing, grading, or drainage prior to starting those  activities. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 372  3. The silt fence shall have a 2-feet min. and a 2½-feet max. height above the original  ground surface.  4. The geotextile fabric shall be sewn together at the point of manufacture to form fabric  lengths as required. Locate all sewn seams at support posts. Alternatively, two sections  of silt fence can be overlapped, provided  that the overlap is long enough and that the  adjacent silt fence sections are close enough together to prevent silt laden water from  escaping through the fence at the overlap.  5. Attach the geotextile fabric on the up-slope side of the posts and secure with staples,  wire, or in accordance with the manufacturer's recommendations. Attach the geotextile  fabric to the posts in a manner that reduces the potential for tearing.  6. Support the geotextile fabric with wire or plastic mesh, dependent on the properties of  the geotextile selected for use. If wire or plastic mesh is used, fasten the mesh securely  to the up-slope side of the posts with the geotextile fabric up-slope of the mesh.  7. Mesh support, if used, shall consist of steel wire with a maximum mesh spacing of 2- inches, or a prefabricated polymeric mesh. The strength of the wire or polymeric mesh  shall be equivalent to or greater than 180 lbs. grab tensile strength. The polymeric mesh  must be as resistant to the same level of ultraviolet radiation as the geotextile fabric it  supports.  8. Bury the bottom of the geotextile fabric 4-inches min. below the ground surface. Backfill  and tamp soil in place over the buried portion of the geotextile fabric, so that no flow can  pass beneath the silt fence and scouring cannot occur. When wire or polymeric back-up  support mesh is used, the wire or polymeric mesh shall extend into the ground 3-inches  min.  9. Drive or place the silt fence posts into the ground 18-inches min. A 12–inch min. depth  is allowed if topsoil or other soft subgrade soil is not present and 18-inches cannot be  reached. Increase fence post min. depths by 6 inches if the fence is located on slopes of  3H:1V or steeper and the slope is perpendicular to the fence. If required post depths  cannot be obtained, the posts shall be adequately secured by bracing or guying to pre- vent overturning of the fence due to sediment loading.  10. Use wood, steel or equivalent posts. The spacing of the support posts shall be a max- imum of 6-feet. Posts shall consist of either:  l Wood with minimum dimensions of 2 inches by 2 inches by 3 feet. Wood shall be  free of defects such as knots, splits, or gouges.  l No. 6 steel rebar or larger.  l ASTM A 120 steel pipe with a minimum diameter of 1-inch.  l U, T, L, or C shape steel posts with a minimum weight of 1.35 lbs./ft.  l Other steel posts having equivalent strength and bending resistance to the post  sizes listed above.  11. Locate silt fences on contour as much as possible, except at the ends of the fence,  2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 373 where the fence shall be turned uphill such that the silt fence captures the runoff water  and prevents water from flowing around the end of the fence.  12. If the fence must cross contours, with the exception of the ends of the fence, place  check dams perpendicular to the back of the fence to minimize concentrated flow and  erosion. The slope of the fence line where contours must be crossed shall not be  steeper than 3H:1V.  l Check dams shall be approximately 1-foot deep at the back of the fence. Check  dams shall be continued perpendicular to the fence at the same elevation until  the top of the check dam intercepts the ground surface behind the fence.  l Check dams shall consist of crushed surfacing base course, gravel backfill for  walls, or shoulder ballast. Check dams shall be located every 10 feet along the  fence where the fence must cross contours.  l Refer to Figure II-3.23: Silt Fence Installation by Slicing Method for slicing method details. The  following are specifications for silt fence installation using the slicing method:  1. The base of both end posts must be at least 2- to 4-inches above the top of the geo- textile fabric on the middle posts for ditch checks to drain properly. Use a hand level or  string level, if necessary, to mark base points before installation.  2. Install posts 3- to 4-feet apart in critical retention areas and 6- to 7-feet apart in standard  applications.  3. Install posts 24-inches deep on the downstream side of the silt fence, and as close as  possible to the geotextile fabric, enabling posts to support the geotextile fabric from  upstream water pressure.  4. Install posts with the nipples facing away from the geotextile fabric.  5. Attach the geotextile fabric to each post with three ties, all spaced within the top 8- inches of the fabric. Attach each tie diagonally 45 degrees through the fabric, with each  puncture at least 1-inch vertically apart. Each tie should be positioned to hang on a post  nipple when tightening to prevent sagging.  6. Wrap approximately 6-inches of the geotextile fabric around the end posts and secure  with 3 ties.  7. No more than 24-inches of a 36-inch geotextile fabric is allowed above ground level.  8. Compact the soil immediately next to the geotextile fabric with the front wheel of the  tractor, skid steer, or roller exerting at least 60 pounds per square inch. Compact the  upstream side first and then each side twice for a total of four trips. Check and correct  the silt fence installation for any deviation before compaction. Use a flat-bladed shovel  to tuck the fabric deeper into the ground if necessary. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 374 Figure II-3.23: Silt Fence Installation by Slicing Method 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 375 Maintenance Standards  l Repair any damage immediately.  l Intercept and convey all evident concentrated flows uphill of the silt fence to a sediment trap- ping BMP.  l Check the uphill side of the silt fence for signs of the fence clogging and acting as a barrier to  flow and then causing channelization of flows parallel to the fence. If this occurs, replace the  fence and remove the trapped sediment.  l Remove sediment deposits when the deposit reaches approximately one-third the height of  the silt fence, or install a second silt fence.  l Replace geotextile fabric that has deteriorated due to ultraviolet breakdown. BMP C234: Vegetated Strip Purpose Vegetated strips reduce the transport of coarse sediment from a construction site by providing a  physical barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use  l Vegetated strips may be used downslope of all disturbed areas.  l Vegetated strips are not intended to treat concentrated flows, nor are they intended to treat  substantial amounts of overland flow. Any concentrated flows must be conveyed through the  drainage system to BMP C241:  Sediment Pond (Temporary) or other sediment trapping  BMP. The only circumstance in which overland flow can be treated solely by a vegetated strip,  rather than by a sediment trapping BMP, is when the following criteria are met (see Table II- 3.12: Contributing Drainage Area for Vegetated Strips): Average Contributing Area Slope Average Contributing Area Per- cent Slope Max Contributing area Flowpath Length 1.5H : 1V or flatter 67% or flatter 100 feet 2H : 1V or  flatter 50% or flatter 115 feet 4H : 1V or  flatter 25% or flatter 150  feet 6H : 1V or  flatter 16.7% or flatter 200  feet 10H : 1V or  flatter 10% or flatter 250  feet Table II-3.12: Contributing Drainage Area for Vegetated Strips 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 376 Design and Installation Specifications  l The vegetated strip shall consist of a continuous strip of dense vegetation with topsoil for a min- imum of a 25-foot length along the flowpath. Grass-covered, landscaped areas are generally  not adequate because the volume of sediment overwhelms the grass. Ideally, vegetated strips  shall consist of undisturbed native growth with a well-developed soil that allows for infiltration  of runoff.  l The slope within the vegetated strip shall not exceed 4H:1V.  l The uphill boundary of the vegetated strip shall be delineated with clearing limits. Maintenance Standards  l Any areas damaged by erosion or construction activity shall be seeded immediately and pro- tected by mulch.  l If more than 5 feet of the original vegetated strip width has had vegetation removed or is being  eroded, sod must be installed.  l If there are indications that concentrated flows are traveling across the vegetated strip, storm- water runoff controls must be installed to reduce the flows entering the vegetated strip, or addi- tional perimeter protection must be installed. BMP C235: Wattles Purpose Wattles are temporary erosion and sediment control barriers consisting of straw, compost, or other  material that is wrapped in netting made of natural plant fiber or similar encasing material. They  reduce the velocity and can spread the flow of rill and sheet runoff, and can capture and retain sed- iment. Conditions of Use  l Wattles shall consist of cylinders of plant material such as weed-free straw, coir, wood chips,  excelsior, or wood fiber or shavings encased within netting made of natural plant fibers  unaltered by synthetic materials.  l Use wattles:  o In disturbed areas that require immediate erosion protection.  o On exposed soils during the period of short construction delays, or over winter months.  o On slopes requiring stabilization until permanent vegetation can be established.  l The material used dictates the effectiveness period of the wattle. Generally, wattles are effect- ive for one to two seasons. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 377  l Prevent rilling beneath wattles by entrenching and overlapping wattles to prevent water from  passing between them. Design Criteria  l See Figure II-3.24: Wattles for typical construction details.  l Wattles are typically 8 to 10 inches in diameter and 25 to 30 feet in length.   l Install wattles perpendicular to the flow direction and parallel to the slope contour.  l Place wattles in shallow trenches, staked along the contour of disturbed or newly constructed  slopes. Dig narrow trenches across the slope (on contour) to a depth of 3- to 5-inches on clay  soils and soils with gradual slopes. On loose soils, steep slopes, and areas with high rainfall,  the trenches should be dug to a depth of 5- to 7- inches, or 1/2 to 2/3 of the thickness of the  wattle.  l Start building trenches and installing wattles from the base of the slope and work up. Spread  excavated material evenly along the uphill slope and compact it using hand tamping or other  methods.  l Construct trenches at intervals of 10- to 25-feet depending on the steepness of the slope, soil  type, and rainfall. The steeper the slope the closer together the trenches.  l Install the wattles snugly into the trenches and overlap the ends of adjacent wattles 12 inches  behind one another.  l Install stakes at each end of the wattle, and at 4-foot centers along entire length of wattle.  l If required, install pilot holes for the stakes using a straight bar to drive holes through the wattle  and into the soil.  l Wooden stakes should be approximately 0.75 x 0.75 x 24 inches min. Willow cuttings or 3/8- inch rebar can also be used for stakes.  l Stakes should be driven through the middle of the wattle, leaving 2 to 3 inches of the stake pro- truding above the wattle. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 378 Figure II-3.24: Wattles 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 379 Maintenance Standards  l Wattles may require maintenance to ensure they are in contact with soil and thoroughly  entrenched, especially after significant rainfall on steep sandy soils.  l Inspect the slope after significant storms and repair any areas where wattles are not tightly  abutted or water has scoured beneath the wattles. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not  pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions  may choose not to accept these products, or may require additional testing prior to consideration for  local use. Products that Ecology has approved as functionally equivalent are available for review on  Ecology’s website at:  https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C236: Vegetative Filtration Purpose Vegetative filtration as a BMP is used in conjunction with detention storage in the form of portable  tanks or BMP C241:  Sediment Pond (Temporary), BMP C206:  Level Spreader, and a pumping sys- tem with surface intake. Vegetative filtration improves turbidity levels of stormwater discharges by fil- tering runoff through existing vegetation where undisturbed forest floor duff layer or established lawn  with thatch layer are present.  Vegetative filtration can also be used to infiltrate dewatering waste  from foundations, vaults, and trenches as long as runoff does not occur. Conditions of Use  l For every five acres of disturbed soil use one acre of grass field, farm pasture, or wooded  area. Reduce or increase this area depending on project size, ground water table height, and  other site conditions.  l Wetlands shall not be used for vegetative filtration.  l Do not use this BMP in areas with a high ground water table, or in areas that will have a high  seasonal ground water table during the use of this BMP.  l This BMP may be less effective on soils that prevent the infiltration of the water, such as hard  till.  l Using other effective source control measures throughout a construction site will prevent the  generation of additional highly turbid water and may reduce the time period or area need for  this BMP.  l Stop distributing water into the vegetated filtration area if standing water or erosion results. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 380 Solera – DevCo, LLC Page 36 C. Correspondence N/A Solera – DevCo, LLC Page 37 D. Site Inspection Form The results of each inspection shall be summarized in an inspection report or checklist that is entered into or attached to the site log book. It is suggested that the inspection report or checklist be included in this appendix to keep monitoring and inspection information in one document, but this is optional. However, it is mandatory that this SWPPP and the site inspection forms be kept onsite at all times during construction, and that inspections be performed and documented as outlined below. At a minimum, each inspection report or checklist shall include: a. Inspection date/times b. Weather information: general conditions during inspection, approximate amount of precipitation since the last inspection, and approximate amount of precipitation within the last 24 hours. c. A summary or list of all BMPs that have been implemented, including observations of all erosion/sediment control structures or practices. d. The following shall be noted: i. locations of BMPs inspected, ii. locations of BMPs that need maintenance, iii. the reason maintenance is needed, iv. locations of BMPs that failed to operate as designed or intended, and v. locations where additional or different BMPs are needed, and the reason(s) why e. A description of stormwater discharged from the site. The presence of suspended sediment, turbid water, discoloration, and/or oil sheen shall be noted, as applicable. f. Confirmation of zero stormwater discharge from the site. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. h. A statement that, in the judgment of the person conducting the site inspection, the site is either in compliance or out of compliance with the terms and conditions of the SWPPP. If the site inspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, as well as a schedule of implementation. Solera – DevCo, LLC Page 38 i. Name, title, and signature of person conducting the site inspection; and the following statement: “I certify under penalty of law that this report is true, accurate, and complete, to the best of my knowledge and belief”. When the site inspection indicates that the site is not in compliance with any terms and conditions of the City of Carnation and Ecology requirements, the Permittee shall take immediate action(s) to: stop, contain, and clean up the unauthorized discharges, or otherwise stop the noncompliance; correct the problem(s); implement appropriate Best Management Practices (BMPs), and/or conduct maintenance of existing BMPs; and achieve compliance with all applicable standards and permit conditions. 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: Solera – DevCo, LLC Page 39 E. Construction Stormwater General Permit (CSWGP) June 2, 2021 Tom Neubauer Solera, LLC 10900 NE 8th STE STE 1200 Bellevue, WA 98004-4460 RE: Coverage under the Construction Stormwater General Permit Permit number: WAR310291 Site Name: Solera Location: NE Sunset Blvd Between NE 10th and NE 12th Renton County: King Disturbed Acres: 13 Dear Tom Neubauer: The Washington State Department of Ecology (Ecology) received your Notice of Intent for coverage under Ecology’s Construction Stormwater General Permit (CSWGP). This is your permit coverage letter. Your permit coverage is effective June 2, 2021. Retain this letter as an official record of permit coverage for your site. You may keep your records in electronic format if you can easily access them from your construction site. You can get the CSWGP, permit forms, and other information at www.ecology.wa.gov/eCoverage-packet. Contact your Permit Administrator, listed below, if you want a copy of the CSWGP mailed to you. Please read the permit and contact Ecology if you have any questions. Electronic Discharge Monitoring Reports (WQWebDMR) This permit requires you to submit monthly discharge monitoring reports (DMRs) for the full duration of permit coverage (from the first full month of coverage to termination). DMRs must be submitted electronically using Ecology’s secure online system, WQWebDMR. To sign up for WQWebDMR go to www.ecology.wa.gov/programs/wq/permits/paris/webdmr.html. If you have questions, contact the portal staff at (360) 407-7097 (Olympia area), or (800) 633-6193/option 3, or email WQWebPortal@ecy.wa.gov. Tom Neubauer June 2, 2021 Page 2 Appeal Process You have a right to appeal coverage under the general permit to the Pollution Control Hearing Board (PCHB). Appeals must be filed within 30 days of the date of receipt of this letter. Any appeal is limited to the general permit’s applicability or non-applicability to a specific discharger. The appeal process is governed by chapter 43.21B RCW and chapter 371-08 WAC. “Date of receipt” is defined in RCW 43.21B.001(2). For more information regarding your right to appeal, go to https://apps.ecology.wa.gov/publications/summarypages/1710007.html to view Ecology’s Focus Sheet: Appeal of General Permit Coverage. Ecology Field Inspector Assistance If you have questions regarding stormwater management at your construction site, please contact your Regional Inspector, Maria Zeman of Ecology's Northwest Regional Office in Bellevue at Maria.Zeman@ecy.wa.gov, or at 425-649-7100. Questions or Additional Information Ecology is here to help. Please review our web page at www.ecology.wa.gov/constructionstormwaterpermit. If you have questions about the Construction Stormwater General Permit, please contact your Permit Administrator, Kendra Henderson at kendra.henderson@ecy.wa.gov, or (360) 407-6556. Sincerely, Jeff Killelea, Manager Program Development Services Section Water Quality Program Issuance Date: November 18, 2020 Effective Date: January 1, 2021 Expiration Date: December 31, 2025 CONSTRUCTION STORMWATER 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. __________________________________ Vincent McGowan, P.E. Water Quality Program Manager Washington State Department of Ecology Construction Stormwater General Permit Page i TABLE OF CONTENTS LIST OF TABLES .................................................................................................................................. ii SUMMARY OF PERMIT REPORT SUBMITTALS ...................................................................................... 1 SPECIAL CONDITIONS ......................................................................................................................... 3 S1. Permit Coverage .............................................................................................................................. 3 S2. Application Requirements ............................................................................................................... 7 S3. Compliance with Standards ............................................................................................................. 9 S4. Monitoring Requirements, Benchmarks, and Reporting Triggers ................................................. 10 S5. Reporting and Recordkeeping Requirements ................................................................................ 17 S6. Permit Fees .................................................................................................................................... 20 S7. Solid and Liquid Waste Disposal .................................................................................................... 20 S8. Discharges to 303(D) or TMDL Waterbodies ................................................................................. 20 S9. Stormwater Pollution Prevention Plan .......................................................................................... 23 S10. Notice Of Termination ................................................................................................................... 32 GENERAL CONDITIONS ..................................................................................................................... 34 G1. Discharge Violations....................................................................................................................... 34 G2. Signatory Requirements ................................................................................................................ 34 G3. Right of Inspection and Entry ......................................................................................................... 35 G4. General Permit Modification and Revocation ............................................................................... 35 G5. Revocation of Coverage Under tPermit ......................................................................................... 35 G6. Reporting a Cause for Modification ............................................................................................... 36 G7. Compliance with Other Laws and Statutes .................................................................................... 36 G8. Duty to Reapply.............................................................................................................................. 36 G9. Removed Substance ....................................................................................................................... 36 G10. Duty to Provide Information .......................................................................................................... 36 G11. Other Requirements of 40 CFR ...................................................................................................... 37 G12. Additional Monitoring .................................................................................................................... 37 G13. Penalties for Violating Permit Conditions ...................................................................................... 37 G14. Upset .............................................................................................................................................. 37 G15. Property Rights .............................................................................................................................. 37 G16. Duty to Comply .............................................................................................................................. 37 G17. Toxic Pollutants .............................................................................................................................. 38 G18. Penalties for Tampering ................................................................................................................. 38 G19. Reporting Planned Changes ........................................................................................................... 38 G20. Reporting Other Information ......................................................................................................... 38 G21. Reporting Anticipated Non-Compliance ........................................................................................ 38 Construction Stormwater General Permit Page ii G22. Requests to Be Excluded From Coverage Under the Permit ......................................................... 39 G23. Appeals........................................................................................................................................... 39 G24. Severability..................................................................................................................................... 39 G25. Bypass Prohibited .......................................................................................................................... 39 APPENDIX A – DEFINITIONS .............................................................................................................. 42 APPENDIX B – ACRONYMS ................................................................................................................ 50 LIST OF TABLES Table 1 Summary of Required Submittals ................................................................................................ 1 Table 2 Summary of Required On-site Documentation ........................................................................... 2 Table 3 Summary of Primary Monitoring Requirements ....................................................................... 12 Table 4 Monitoring and Reporting Requirements ................................................................................. 14 Table 5 Turbidity, Fine Sediment & Phosphorus Sampling and Limits for 303(d)-Listed Waters ................................................................................................................ 22 Table 6 pH Sampling and Limits for 303(d)-Listed Waters ..................................................................... 22 Construction Stormwater General Permit Page 1 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.D Request for Chemical Treatment Form As necessary Written approval from Ecology is required prior to using chemical treatment (with the exception of dry ice, CO2 or food grade vinegar 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 S2.A Notice of Permit Transfer As necessary G19 Notice of Planned Changes As necessary G21 Reporting Anticipated Non-compliance As necessary 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. Construction Stormwater General Permit Page 2 Table 2 Summary of Required On-site Documentation Document Title Permit Conditions Permit Coverage Letter See Conditions S2, S5 Construction Stormwater General Permit (CSWGP) See Conditions S2, S5 Site Log Book See Conditions S4, S5 Stormwater Pollution Prevention Plan (SWPPP) See Conditions S5, S9 Site Map See Conditions S5, S9 Construction Stormwater General Permit Page 3 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 and 4. 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 related to construction-support activity as 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 category 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 groundwater, 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 S1.F). c. Routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of a facility. 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 Construction Stormwater General Permit Page 4 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 groundwater 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. 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 groundwater, are prohibited: Construction Stormwater General Permit Page 5 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. 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. Construction Stormwater General Permit Page 6 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. F. 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 five (5) acres and the site is not a portion of a common plan of development or sale that will disturb five (5) acres or greater. 2. Calculation of Erosivity “R” Factor and Regional Timeframe: a. The project’s calculated rainfall erosivity factor (“R” Factor) must be less than five (5) during the period of construction activity, (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 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/resourcesguida nce.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 Construction Stormwater General Permit Page 7 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. 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 S1.F.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. S2. APPLICATION REQUIREMENTS A. Permit Application Forms 1. Notice of Intent Form 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://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 c. The operator must submit the NOI at least 60 days before discharging stormwater from construction activities and must submit it prior to 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, coverage under the general permit will automatically commence on the 31st 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). See S8.B for Limits on Coverage for New Discharges to TMDL or 303(d)-Listed Waters. 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, the applicant must provide notice of the Construction Stormwater General Permit Page 8 selection of an equivalent BMP to Ecology at least 60 days before intended use of the equivalent BMP. e. 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. Related portions of the Stormwater Pollution Prevention Plan (SWPPP) that address the management of contaminated and potentially contaminated construction stormwater and dewatering water, iv. Dewatering plan and/or dewatering contingency plan. 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: i. The Permittee submits a complete Transfer of Coverage Form to Ecology, signed by the current and new discharger and containing a specific date for transfer of permit responsibility, coverage and liability (including any Administrative Orders associated with the permit); and ii. Ecology does not notify the current discharger and new discharger of 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 indicate the remaining permitted acreage after the transfer. Transfers do not require public notice. 3. Modification of Coverage Form Permittees must notify Ecology regarding any changes to the information provided on the NOI by submitting an Update/Modification of Permit Coverage form in accordance with General Conditions G6 and G19. 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. Construction Stormwater General Permit Page 9 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 be run after the NOI has been submitted and 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 total number of acres to be disturbed over the lifetime of the project. 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 and the receiving water(s) the system discharges to. 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. S3. COMPLIANCE WITH STANDARDS A. Discharges must not cause or contribute to a violation of surface water quality standards (Chapter 173-201A WAC), groundwater quality standards (Chapter 173-200 WAC), sediment management standards (Chapter 173-204 WAC), and human health-based criteria in the Federal water quality criteria applicable to Washington. (40 CFR Part 131.45) Discharges that are not in compliance with these standards are prohibited. 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: Construction Stormwater General Permit Page 10 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 management 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 groundwater, the groundwater discharges must also meet the terms and conditions of this CSWGP. Permittees who discharge to groundwater through an injection well must also comply with any applicable requirements of the Underground Injection Control (UIC) regulations, Chapter 173-218 WAC. 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 Construction sites one (1) acre or larger that discharge stormwater to surface waters of the State must have site inspections conducted by a Certified Erosion and Sediment Control Lead (CESCL). Sites less than one (1) acre may have a person without CESCL certification conduct inspections. (See Special Conditions S4.B.3 and B.4, below, for detailed requirements of the Permittee’s CESCL.) Site inspections must include all areas disturbed by construction activities, all BMPs, and all stormwater discharge points under the Permittee’s operational control. 1. 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. The SWPPP must identify the CESCL or inspector, who must be present on site or on-call at all times. The CESCL (sites one (1) acre or more) 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.) 2. The CESCL or inspector must examine stormwater visually for the presence of suspended sediment, turbidity, discoloration, and oil sheen. BMP effectiveness must be evaluated to Construction Stormwater General Permit Page 11 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, 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. 3. 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 (1) day do not require daily inspections. For example, if a stormwater pond discharges continuously over the course of a week, only one (1) inspection is required that week.) Inspection frequency may be reduced to once every calendar month for inactive sites that are temporarily stabilized. 4. 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. c. The general conditions during inspection. d. The approximate amount of precipitation since the last inspection. e. The approximate amount of precipitation within the last 24 hours. f. A summary or list of all implemented BMPs, including observations of all erosion/sediment control structures or practices. g. A description of: i. BMPs inspected (including location). ii. BMPs that need maintenance and why. iii. BMPs that failed to operate as designed or intended, and iv. Where additional or different BMPs are needed, and why. h. A description of stormwater discharged from the site. The Permittee must note the presence of suspended sediment, turbidity, discoloration, and oil sheen, as applicable. Construction Stormwater General Permit Page 12 i. Any water quality monitoring performed during inspection. j. General comments and notes, including a brief description of any BMP repairs, maintenance, or installations made following the inspection. k. An implementation schedule for 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. l. A summary report of the inspection. m. 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 concrete or recycled concrete placed or poured 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.a or b. 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.4.a. Construction Stormwater General Permit Page 13 C. Turbidity/Transparency Sampling Requirements 1. Sampling Methods a. If construction activity involves the disturbance of five (5) acres or more, the Permittee must conduct turbidity sampling per Special Condition S4.C.4.a, below. b. If construction activity involves one (1) acre or more but fewer than five (5) acres of soil disturbance, the Permittee must conduct either transparency sampling or turbidity sampling per Special Condition S4.C.4.a or b, below. 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) in the SWPPP and on the 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. 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. Construction Stormwater General Permit Page 14 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 Turbidity NTU SM2130 Weekly, if discharging 25 NTUs Transparency Cm Manufacturer instructions, or Ecology guidance Weekly, if discharging 33 cm 5. Turbidity/Transparency Benchmark Values and Reporting Triggers The benchmark value for turbidity is 25 NTUs. 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 and follow S5.F – Noncompliance Notification for reporting requirements applicable to discharges which exceed the numeric effluent limit for turbidity. a. Turbidity 26 – 249 NTUs, or Transparency 32 – 7 cm: If the discharge turbidity is 26 to 249 NTUs; or if discharge transparency is 32 to 7 cm, the Permittee must: i. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs, and no later than 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. 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. 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 Construction Stormwater General Permit Page 15 management process described below. For discharges which are subject to a numeric effluent limit for turbidity, see S5.F – Noncompliance Notification. i. Within 24 hours, 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), 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 These numbers and a link to the ERTS reporting page are also listed at the following website: http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html. 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. iii. Sample discharges daily until: a) Turbidity is 25 NTUs (or lower); or b) Transparency is 33 cm (or greater); or c) The Permittee has demonstrated compliance with the water quality standard 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 *Note: background turbidity in the receiving water must be measured immediately upstream (upgradient) or outside of the area of influence of the discharge. d) The discharge stops or is eliminated. iv. Review the SWPPP for compliance with Special Condition S9 and make appropriate revisions within seven (7) days of the date the discharge exceeded the benchmark. Construction Stormwater General Permit Page 16 v. Document BMP implementation and maintenance in the site log book. Compliance with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with permit benchmarks. 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 placed or 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. 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. 2. During the applicable pH monitoring period defined below, the Permittee must obtain a representative sample of stormwater and conduct pH analysis at least once per week. a. For sites with significant concrete work, the Permittee must begin the pH sampling period when the concrete is first placed or poured and exposed to precipitation, and continue weekly throughout and after the concrete placement, pour and curing period, until stormwater pH is in the range of 6.5 to 8.5 (su). b. 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). c. 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. 3. 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. 4. The benchmark value for pH is 8.5 standard units. Anytime sampling indicates that pH is 8.5 or greater, the Permittee must either: a. Prevent the high pH water (8.5 or above) from entering storm sewer systems or surface waters of the state; 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, dry ice or food grade vinegar. The Permittee must obtain written approval from Ecology before using any form of chemical treatment other than CO2 sparging, dry ice or food grade vinegar. Construction Stormwater General Permit Page 17 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 notify Ecology within 24 hours of analysis either by calling the applicable Ecology Region’s Environmental Report Tracking System (ERTS) number by phone or by submitting an electronic ERTS report (through Ecology’s Water Quality Permitting Portal (WQWebPortal) – Permit Submittals when the form is available). See the CSWGP website 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 G12 (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. 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, WA 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 must 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 the first full month following the effective date of permit coverage up until Ecology has approved termination of the coverage). For more information, contact Ecology staff using information provided at the following website: 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 five (5) 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 Construction Stormwater General Permit Page 18 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 samples or monitors any pollutant more frequently than required by this permit using test procedures specified by Special Condition S4 of this permit, the sampling results for 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 or fuels or other materials, catastrophic pond or slope failure, and discharges that violate water quality standards), or exceed 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 go to https://ecology.wa.gov/About-us/Get-involved/Report-an-environmental-issue to find contact information for the regional offices.) 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 (See S5.F.3, below, for details on submitting results in a report). 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. Construction Stormwater General Permit Page 19 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 e. Erosivity Waiver (if applicable) 2. The Permittee must address written requests for plans and records listed above (Special Condition S5.G.1) as follows: 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 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. Construction Stormwater General Permit Page 20 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 Water Bodies 1. Permittees who discharge to segments of water bodies 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, 2021, 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 Construction sites that discharge to a TMDL or 303(d)-listed waterbody are not eligible for coverage under this permit unless the operator: Construction Stormwater General Permit Page 21 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 only after Ecology makes an affirmative determination that the discharge will not cause or contribute to the existing impairment or exceed the TMDL. 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. 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 must sample discharges daily until the violation is corrected and comply with the non-compliance notification requirements in Special Condition S5.F. Construction Stormwater General Permit Page 22 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) 1 Permittees 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). 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 su 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 must 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 Construction Stormwater General Permit Page 23 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, unless 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. iii. 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, 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. 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 identify best management practices (BMPs) which prevent erosion and sedimentation, and to reduce, eliminate or prevent stormwater contamination and water pollution from construction activity. 2. To prevent violations of surface water quality, groundwater quality, or sediment management standards. 3. To control peak volumetric flow rates and velocities of stormwater discharges. Construction Stormwater General Permit Page 24 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. 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 Construction Stormwater General Permit Page 25 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 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. f. Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. Construction Stormwater General Permit Page 26 3. Control Flow Rates a. Protect properties and waterways downstream of construction 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, as required by local plan approval authority. b. Where necessary to comply with Special Condition S9.D.3.a, construct stormwater infiltration or detention BMPs as one of the first steps in grading. Assure that detention BMPs 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 sedimentation 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: 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 Construction Stormwater General Permit Page 27 control fabrics and matting, soil application of polyacrylamide (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). b. The Permittee must divert off-site stormwater (run-on) or groundwater 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. Construction Stormwater General Permit Page 28 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 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. Construction Stormwater General Permit Page 29 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. Minimize storage of hazardous materials on-site. Safety Data Sheets (SDS) should be supplied for all materials stored. Chemicals should be kept in their original labeled containers. 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 of 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 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 onto the ground, or into storm drains, open ditches, streets, or streams. Washout of small concrete handling equipment may be disposed of in a formed area awaiting concrete where it will not contaminate surface or groundwater. 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 Construction Stormwater General Permit Page 30 prohibited. At no time shall concrete be washed off into the footprint of an area where an infiltration BMP will be installed. i. Obtain written approval from Ecology before using any chemical treatment, with the exception of CO2, dry ice or food grade vinegar, 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, in conjunction with BMPs to reduce sedimentation before discharge to a sediment trap or sediment pond. b. Permittees may discharge clean, non-turbid dewatering water, such as well-point groundwater, 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. 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. Construction Stormwater General Permit Page 31 12. Manage the Project a. Phase development projects to the maximum degree practicable and take into account seasonal work limitations. b. 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. 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 on-site LID Stormwater Management is to reduce the disruption of the natural site hydrology through infiltration. LID BMPs are permanent facilities. a. Permittees must protect all LID BMPs (including, but not limited to, 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 BMPs 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. b. Permittees must 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. 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 or base materials. 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 BMPs 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. Construction Stormwater General Permit Page 32 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. 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 Partial terminations of permit coverage are not authorized. 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 Special Condition S2.A), 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, WA 98504-7696 Construction Stormwater General Permit Page 33 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 31st calendar day following the date Ecology receives a complete NOT form, unless Ecology notifies the Permittee that 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 34 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. 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 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. Construction Stormwater General Permit Page 35 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. 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. Construction Stormwater General Permit Page 36 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, WA 98504-7696 G9. REMOVED SUBSTANCE 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. G10. 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)]. Construction Stormwater General Permit Page 37 G11. OTHER REQUIREMENTS OF 40 CFR All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference. G12. ADDITIONAL MONITORING Ecology may establish specific monitoring requirements in addition to those contained in this permit by administrative order or permit modification. G13. 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. 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. G14. 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. G15. PROPERTY RIGHTS This permit does not convey any property rights of any sort, or any exclusive privilege. G16. 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. Construction Stormwater General Permit Page 38 G17. 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. G18. 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. G19. 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: 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. G20. 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. G21. 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 unavoidable interruption of Construction Stormwater General Permit Page 39 operation and degradation of effluent quality, must be scheduled during non-critical water quality periods and carried out in a manner approved by Ecology. G22. 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. G23. 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. G24. 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. G25. 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 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. Construction Stormwater General Permit Page 40 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. 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 Construction Stormwater General Permit Page 41 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 42 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, 2021, or before the date the operator’s complete permit application is received by Ecology, whichever is later. TMDLs completed after a 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. 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 43 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 groundwater. Construction Activity means land disturbing operations including clearing, grading or excavation which disturbs the surface of the land (including off-site disturbance acreage related to construction-support activity). 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. Construction Support Activity means off-site acreage that will be disturbed as a direct result of the construction project and will discharge stormwater. For example, off-site equipment staging yards, material storage areas, borrow areas, and parking areas. 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 soil means soil which contains contaminants, pollutants, or hazardous substances that do not occur naturally or occur at levels greater than natural background. Contaminated groundwater means groundwater 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. 2. The pollutant removal performance expected from the BMPs selected. Construction Stormwater General Permit Page 44 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 groundwater 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 groundwater 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 groundwater 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 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 completion of all soil disturbing activities at the site and the establishment of permanent vegetative cover, or equivalent permanent stabilization measures (such as pavement, riprap, gabions, or geotextiles) which will prevent erosion. See the applicable Stormwater Management Manual for more information on vegetative cover expectations and equivalent permanent stabilization measures. Construction Stormwater General Permit Page 45 Groundwater 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 sub-stance as defined in RCW 70.105.010(14) 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, 42U.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 • 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. Construction Stormwater General Permit Page 46 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 the 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 non-stormwater 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 groundwater drainage, redirecting stream natural flows, or for conveyance of irrigation water/return flows that coincidentally convey stormwater are considered the receiving water. 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. Construction Stormwater General Permit Page 47 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 groundwater quality or sediment management standards. Significant Concrete Work means greater than 1000 cubic yards placed or 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 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. Construction Stormwater General Permit Page 48 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. Transfer of Coverage (TOC) means a request for transfer of coverage under this general permit as specified by Special Condition S2.A 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. 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. 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 Construction Stormwater General Permit Page 49 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 50 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 CPD Common Plan of Development 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 Solera – DevCo, LLC Page 40 F. 303(d) List Waterbodies / TMDL Waterbodies Information Not applicable to this project Solera – DevCo, LLC Page 41 G. 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HEARTLAND CONSTRUCTION (HASP) HEALTH & SAFETY PLAN “SOLERA” Project Address: 2842 NE Sunset Boulevard Renton WA, 98056 Project Team: Heartland Construction- Ben Hansen 425-327-6925 Heartland Construction- Justin Riener 208-559-6287 Heartland Construction- Michael Harter 425-249-1998 Heartland Construction- Michael Jimma 425-533-6532 Heartland Construction- Craig Vierling 206-965-5745 Heartland Construction Health and Safety Plan Site Name: Renton Highlands, Solera Project Site Address: 2822 NE Sunset Blvd, Renton, Washington Client: DevCo, LLC Phone: NA Heartland Construction - Senior Superintendent /Site Contact Mr. Benham Hansen Phone: (425) 327-6925 Heartland Construction - Assistant Superintendent / Point of Contact for Remediation Mr. Justin Reiner Phone: (208) 559-6287 Signature Safety – Safety Lead Mr. Darin Parker Phone: (206) 300-6384 Elk Heights - Safety Lead Mr. Ryan Kelly Phone: (425) 471-2085 TRC - Project Manager Mr. Eric Caddey Phone: (425)-281-3629 Planned Activities: Location Within Site: Dates: Remedial excavation, loading, transport of impacted soil. Central portion of the Site at the location of the former dry cleaners. June 2021 through August 2021 Estimation of Hazards to TRC Personnel: Tetrachloroethene (PCE) and its chemical breakdown products, homeless squatters, mechanical equipment, overhead hazards, electrical power, subsurface utilities, manual lifting, slips, trips, falls, and potential exposure to COVID-19 (see Attachment A: COVID-19 Guidelines for Field Activities and COVID-19 Questionnaire for Onsite Workers). Physical Description of the Facility: Flat topography, asphalt paved parking lot. The Site formerly encompassed a former strip mall along the north side of Sunset Blvd that has been demolished and the demolition debris has been removed. Operation Description of the Facility: Vacant commercial property. Facility Status: Not operational - vacant. Remedial excavation work will be performed at the facility under this health and safety plan. Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 2 Hazard Assessment Chemical State: Liquid Solid Gas Vapor Unknown Chemical Characteristics: Corrosive Flammable Toxic Volatile Inert Other: Describe Potential Chemical Hazards and Modes of Exposure Chemical Hazards: PCE and lesser chlorinated breakdown products such as trichloroethene (TCE), cis-1,2-dichloroethene (cDCE), and vinyl chloride. Potential Modes of Exposure: Ingestion, inhalation, dermal absorption, and eye contact Potential Chemical Hazards Chemical Name Action Levels Exposure Route Target Organs Symptoms PEL STEL IDLH Dry Cleaner Related Chemicals – Chlorinated Volatile Organics Tetrachloroethene (PCE) 100 ppm 150 ppm Inhalation, skin absorption, ingestion, skin/eye contact Eyes, skin, respiratory system, liver, kidneys, CNS Irritation eyes, skin, nose, throat, respiratory system, nausea, flush face, neck, dizziness, incoordination, headache, drowsiness, skin redness, liver damage [potential occupational carcinogen] Trichloroethene (TCE) 100 ppm 1,000 ppm Inhalation, skin absorption, ingestion, skin/eye contact Eyes, skin, respiratory system, liver, kidneys, CNS Irritation eyes, skin, headache, visual disturbance, weakness, exhaustion, dizziness, tremor, drowsiness, nausea, vomiting, dermatitis, cardiac arrhythmias, paresthesia, liver injury [potential occupational carcinogen] 1,2-Dichloroethene (cis and trans) 200 ppm 1,000 ppm Inhalation, skin absorption, ingestion, skin/eye contact Eyes, respiratory system, CNS Irritation eyes, respiratory system, CNS depression. Vinyl chloride 1 ppm 5 ppm Inhalation, skin/eye contact Liver, CNS, blood, respiratory system, lymphatic system Weakness, exhaustion, abdominal pain, gastrointestinal bleeding, enlarged liver, pallor or cyanosis of extremities, liquid: frostbite [potential occupational carcinogen] Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 3 Describe Potential Physical Worker Hazards: Working with electrical motors and equipment, hot motor casings, overhead hazards, and hydraulic equipment, slip, trip, and fall, homeless squatters, manual lifting. Potential Physical Hazards Heat Stress Cold Stress Explosion/Flammability Noise Confined-Space Entry Oxygen-Deficient Atmosphere Traffic or heavy equipment Heights Slip, trip, fall Overhead hazards Dust (non-toxic) Other: Homeless Squatters and COVID-19 (see attachments) Prevention of Physical Hazards Category Cause Preventive Measures Head Hazards Falling and/or sharp objects, bumping hazards. Hard hats must be worn by all personnel at all times when working around overhead hazards, traffic, or heavy equipment. Foot/Ankle Hazards Sharp objects, dropped objects, uneven and/or slippery surfaces, and chemical exposure. Chemical resistant, steel-toed boots must be worn at all times on-site. Eye Hazards Sharp objects, poor lighting, bright lights (welding equipment), exposure due to splashes. Safety glasses/face shields will be worn when appropriate. Shaded welding protection will be worn when appropriate. Electrical Hazards Underground utilities, overhead utilities, motors, electrical panels equip. and breakers. Utility locator service mark-outs, visual inspection of work area prior to starting work. Mechanical Hazards Heavy equipment such as drill rigs, service trucks, excavation equipment, saws, drills, etc. Competent operators, backup alarms, regular maintenance, daily mechanical checks, proper guards, high visibility safety vests. Noise Hazards Machinery creating >85 decibels TWA, >115 decibels continuous noise, or peak at >140 decibels. Wear earplugs or protective earmuffs. Fall Hazards Elevated and/or slippery or uneven surfaces. Trips caused by poor "housekeeping" practices. Care should be used to avoid such accidents and to maintain good "housekeeping". Fall protection devices must be used when work proceeds on elevated surfaces. Lifting Hazards Injury due to improper lifting techniques, overreaching/overextending, heavy objects. Use proper lifting techniques, mechanical devices where appropriate. Lighting Hazards Improper illumination. Limit work to daylight hours or rent additional construction lighting. Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 4 Site Activity Considerations Will Client Site Representative be Present? Yes No Sometimes Exact Locations of Chemicals: Known Assumed Unknown Identify Nearest Off-Site Population: Rural Urban Industrial Commercial Residential Monitoring Equipment PID FID Combustible gas indicator Colorimetric tubes Particulate meter Carbon monoxide meter H2S/O2 Meter Other (describe): Monitoring Action Guidelines Air monitoring will be performed by the onsite TRC Site Safety Officer (SSO). Air monitoring action guidelines that the TRC SSO will follow are listed below: Instrument Reading Action Required PID with colorimetric tube verification of the presence of vinyl chloride. (Note: All measurements taken within the breathing space of site workers.) >1 but <5 ppm Wait 15 minutes and measure again. Level is based on Short-Term Exposure Limit (15-min TWA) for vinyl chloride. >1 but <5 ppm for >15 minutes Upgrade to Level C (full- or half-face respirator) protection with combination HEPA/organic vapor cartridges. >5 ppm for vinyl chloride Evacuate all workers from work area. Notify Project Manager and Company Safety Officer. If permitted, retest atmosphere while wearing full- or half-face respirator with combination HEPA/organic vapor cartridges. PID with colorimetric tube verification of no presence of vinyl chloride. (Note: All measurements taken within the breathing space of site workers.) >100 but <150 ppm Wait 15 minutes and measure again. Level is based on Short-Term Exposure Limit (15-min TWA) for PCE. >100 but <150 ppm for >15 minutes Upgrade to Level C (full- or half-face respirator) protection with combination HEPA/organic vapor cartridges. >150 ppm for PCE Evacuate all workers from work area. Notify Project Manager and Company Safety Officer. If permitted, retest atmosphere while wearing full- or half-face respirator with combination HEPA/organic vapor cartridges. Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 5 Special Safety Considerations If there is more than one level of hazard, or if there are multiple “sites” within a site, the hazards associated with each should be considered. A separate “Special Safety Considerations” section should be completed for each “site.” Work Location: Remedial excavation area has known and potential chlorinated solvent impacts to soil. Objective of work at this Location: Remove soil impacted by chlorinated solvents from former dry cleaner to achieve applicable cleanup levels throughout the excavation. Level of Protection Planned: Level C Level D Level D-Modified (explain below) Modifications to Level of Protection: Hard hat, safety glasses, steel toe boots, DOT-approved safety vest, and hearing protection required when working near drill rigs, traffic, or heavy equipment. COVID- 19 appropriate face coverings required when working within 6 feet of other people. Types of PPE to be Used Foot Steel-toed, steel shank boots. Rubber steel toed boots or rubber boot covers required if boot decontamination is warranted. Hand Double layer of nitrile gloves when handling potentially contaminated media, temperature-appropriate gloves for protection during cold weather. Eye/Face Safety glasses, COVID-19 appropriate face covering Clothing Temperature appropriate, long pants are required. Tyvek coveralls should be available to all on-site workers. Respiratory Based on monitoring requirements (full- or half-face respirator should be available to all on-site workers). Additional Gear Hardhat, earplugs, face shield, DOT-approved high visibility safety vest Work Party Name Responsibility Level of Protection Benham Hansen (Heartland Construction) Senior Superintendent / Site Contact Level D Modified Justin Reiner (Heartland Construction) Assistant Superintendent / Point of Contact for Remediation Level D Modified Darin Parker (Signature Safety) Safety Lead Level D Modified Ryan Kelly (Elk Heights) Safety Lead Level D Modified Level D Modified Level D Modified Level D Modified Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 6 Criteria for Changing Personal Protection Upgrade to Level C PPE (full or half face respirator) if air monitoring threshold limits are exceeded. When to upgrade to coated Tyvek when there is a significant potential for dermal contact with contaminated wet media (mud or water). Upgrade from safety glasses to face shield if significant splash potential exists from contaminated media. Criteria for Implementing Engineering Controls: None Decontamination Procedures Remove PPE and wash hands and face with potable water and soap prior to eating or leaving Site. Eye wash kit available in vehicles at the Site. Work Limitations (i.e., time of day, conditions, etc.) Daylight hours only. Placement of Disposable Materials Non-contaminated materials will be retained in plastic garbage bags that will be disposed as solid waste at appropriate disposal receptacles. Contaminated materials will be placed in DOT-approved 55- gallon drums that will be temporarily left on-site for proper disposal following characterization. Placement of Investigation-Derived Residuals (i.e., drilling spoils, decon. water, purge/dev. water) Liquid and solids will be disposed in accordance with local, state, and federal regulations. Location of Nearest: Cellular Phone: With Heartland Construction field representative Running Water: Adjacent service station. Public Road: Sunset Blvd. Lavatory: Onsite portable toilets Emergency Planning Emergency rally points are indicated on Attachment D Service Name Number Local Police: Renton PD 911 Local EMS: Renton FD 911 Local Fire Department: Renton FD 911 Local Hospital: Valley Medical Center 425-228-3450 Client Contact: Dalton Arndt 253-606-0715 Site Phone Number: Heartland Construction personnel Craig Vierling (206) 965-5745 Benham Hansen (425) 327-6925 Justin Reiner (208) 559-6287 Heartland Construction Office Front Desk 425-453-9551 Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 7 Directions to Nearest Medical Facility (Map Attached): The recommended route to Valley Medical Center is highlighted on the attached map in Attachment B. The hospital is located approximately 5.8 miles from the site. Approvals Title Signature Date Heartland Construction Project Manager Heartland Construction Site Safety Lead Heartland Construction Senior Superintendent Heartland Construction Assistant Superintendent Health and Safety Plan, Renton Highlands, Sunset Project 2822 NE Sunset Blvd, Renton, WA June 11, 2021 8 Additional Site Personnel Printed Name and Company Approvals Signature Date Daily Safety Meeting Date: Heartland Construction Project Number: Site Address: 2822 NE Sunset Blvd, Renton, Washington Heartland Construction Personnel Conducting Meeting: Known or Suspected Potential Hazards Personal Protective Equipment Chemicals of Potential Concern Hard Hat Traffic (Vehicle and Pedestrian) Eye Protection Trips High-Visibility Clothing Falls Flame-Resistant Clothing Drilling Equipment Protective Footwear Excavation Equipment Coveralls Noise Hearing Protection Hot/Cold Respirator Utilities, Subsurface, and Overhead Exclusion Zone (Cones, Signs, Etc.) Other, describe: COVID-19 protocols (see Attachment A) Other, describe: COVID-19 (face masks, distancing, PPE, hygiene, see Attachment A) Locations of Emergency Equipment Decon, Emergency Signals, Rally Point, Etc. Fire Extinguishers Decon Procedures Eye Wash Waste Management First Aid Kit Hand Signals for Shutdown Nearest Medical Facility Audible Signals for Shutdown Potable Water Primary Rally Point (see Attachment C) Restroom Secondary Rally Point (see Attachment C) Equipment Shutdown Procedures Other Emergency Info, Describe: Other, Describe: Persons Attending Safety Meeting Name / Affiliation (Print) Time / / / / / / / Attachment A COVID-19 Attachments Attachment A: COVID-19 Guidelines for Field Activities 1 | Page 1. ASSESSING FIELD ACTIVITIES FOR COVID-19 RISK Work activities should be assessed to identify possible hazards and the precautions necessary to mitigate risk to an acceptable level, including risks associated with COVID-19. Heartland Construction is following the US Occupational Safety and Health Administration’s (OSHA) risk assessment guidance for COVID-19. Project-specific controls that are developed through the risk assessment process must be communicated to project employees and also listed in the project Health and Safety Plan. 1.1. Risk Assessment To determine appropriate precautions, OSHA has divided job tasks into four risk exposure levels: very high, high, medium, and lower risk. The majority of Heartland Construction’s work is considered Low risk. • Very High: Exposure risk jobs are those with high potential for exposure to known or suspected sources of COVID-19 during specific medical, postmortem, or laboratory procedures. Workers in this category include healthcare workers and healthcare or laboratory personnel collecting or handling specimens from known or suspected COVID- 19 patients. o Precautions: This project does not include Very High-risk work. • High: Exposure risk jobs are those with high potential for exposure to known or suspected sources of COVID-19. Workers in this category include healthcare delivery and support staff (e.g., doctors, nurses, and other hospital staff who must enter patients’ rooms) exposed to known or suspected COVID-19 patients. o Precautions: This project does not include High-risk work. • Medium: Exposure risk jobs include those that require frequent and/or close contact with (i.e., within 6 feet of) people who may be infected with COVID-19, but who are not known or suspected COVID-19 patients. In areas without ongoing community transmission, workers in this risk group may have frequent contact with travelers who may return from international locations with widespread COVID-19 transmission. In areas where there is ongoing community transmission, workers in this category may have contact be with the general public (e.g., in schools, high-population-density work environments, and some high-volume retail settings). o Precautions: • Continue to follow the CDC’s guidelines for social distancing and hand hygiene. • Where appropriate, limit client and third-party access to the worksite or restrict access to only certain workplace areas. • Consider strategies to minimize face-to-face contact (e.g., drive through windows, phone-based communication, telework). Attachment A: COVID-19 Guidelines for Field Activities 2 | Page Employees and Project Managers with medium exposure risk may need to wear some combination of gloves (i.e., nitrile), a face mask (or ½ mask tight-fitting respirator), and/or a face shield or goggles. PPE ensembles for workers in the medium exposure risk category will vary by work task, the results of the hazard assessment, and the types of exposures workers have on the job. • Lower: Exposure risk (caution) jobs are those that do not require contact with people known to be, or suspected of being, infected with COVID-19 nor frequent close contact with (i.e., within 6 feet of) the general public. Workers in this category have minimal occupational contact with the public and other coworkers. o Precautions – While OSHA does not recommend specific controls for Low-risk work, continue to follow the CDC’s primary precautions including social distancing and hand hygiene. 1.2. Best Practices Additional best practices that can be used to further mitigate potential exposure to COVID-19. In addition, the CDC’s COVID-19 guidelines which include social distancing and hand hygiene, the following options should be considered. • Travel o Drive in separate vehicles o Consider completing task alone o Have passenger sit in back seat o Sanitize your hands after using the fuel pump o Sanitize interior surfaces of rental vehicles o Driving instead of flying • Project Sites o Use disposable chemical resistant gloves (i.e., nitrile) when disinfectant wipes are not available o Schedule work during “off hours” when less people are around o Wait until 3 days after last person left the area, if possible o Consider using a ½ mask tight-fitting respirator when N95 masks are not available (if deemed appropriate) o Contact clients via telephone or video conference instead of face-to-face meetings • Construction sites o Avoid “tailgate meetings” or “water cooler meetings” without following social distancing protocols o Avoid sharing pens/pencils Attachment A: COVID-19 Guidelines for Field Activities 3 | Page o Safety Meetings should be held in groups of 10 or less and should observe 6’ personal distance o Stager lunch times to minimize social gatherings; consider eating in separate areas o All lunch waste, bottles and cans should be disposed of immediately after use o Never share PPE (hard hats, high visibility vets, personal floatation device, safety glasses, etc. o Avoid community coffee pots in field offices o Provide disposable paper cups at drinking stations o Wear gloves when operating equipment and if possible, limit one operator to a piece of equipment. Sanitize controls after use o No sharing hand tools o Set up hand cleaning or sanitizing stations at various locations on the site, ideally near port-o-lets o Put your clothing directly in the washing machine at the end of shift o Limit number of workers in confined spaces as much as possible o Use telephones or Skype meetings to avoid face-to-face meetings when possible 2. SYMPTOMS AND PRECAUTIONS FOR COVID-19 2.1. Background The 2019 novel coronavirus, or COVID-19, is a new respiratory virus first identified in Wuhan, Hubei Province, China. It’s called a “novel” — or new — coronavirus, because it is a coronavirus that has not been previously identified. Both the COVID-19 and influenza (flu) are respiratory illnesses, which have similar symptoms. Both are contagious and both can be mild or severe, even fatal in rare cases. The key difference between the novel coronavirus and influenza is we know what to expect from the flu. 2.2. Symptoms of COVID-19 Initial symptoms of COVID-19 usually include fever greater than 100.4°F (38.0°C), cough, and shortness of breath. However, not all affected individuals will exhibit all symptoms. If you experience these symptoms or have been in recent close contact with someone with these symptoms, notify your doctor and stay home. Attachment A: COVID-19 Guidelines for Field Activities 4 | Page 2.3. Steps to Follow If You Develop Symptoms Symptoms and Warning Signs Take the following steps These symptoms may appear 2-14 days after exposure. • Fever, greater than 100.4°F (38.0°C) • Cough • Shortness of breath 1. Notify your field and direct supervisor that you feel ill. 2. Supervisor shall notify Senior Superintendent (425) 327-6925), and your HR Business Partner immediately. 3. Immediately isolate yourself and return to your place of lodging (return home if nearby). 4. Contact your personal healthcare provider asap for evaluation and follow their instructions. 5. Update your field and direct supervisor of your health and work status (e.g., when do you expect to return to work). 6. If you’re diagnosed with COVID-19 notify your Senior Superintendent ((425) 327-6925) and your HR Business Partner immediately. This communication will be treated as confidential. If you develop any of the following emergency warning signs: • Difficulty breathing or shortness of breath, • Persistent pain or pressure in the chest, • New confusion or inability to arouse, • Bluish lips or face This list is not all inclusive so please consult with your medical provider for further guidance. 1. Get medical attention immediately. 2. If you’re diagnosed with COVID-19, notify your Senior Superintendent (425) 327-6925, and your HR Business Partner immediately. This communication will be treated as confidential. Source: CDC COVID-19 Symptoms https://www.cdc.gov/coronavirus/2019-ncov/about/symptoms.html 2.4. Transmission Both COVID-19 and the flu can be spread from person to person through droplets caused by an infected person coughing, sneezing, or talking. Flu can be spread by an infected person for several days before their symptoms appear, and COVID-19 is believed to be spread in the same manner, but this has not been conclusively demonstrated. 2.5. Precautions • Practice Social Distancing o Practice social distancing by avoiding large gatherings and maintaining distance o (approximately 6 feet) from others when possible. Attachment A: COVID-19 Guidelines for Field Activities 5 | Page o Do not share eating or drinking utensils, avoid close conversation, and other direct physical contact like hand shaking. “Close contact” does not include activities such as walking by a person or briefly sitting across an office. • Hand Hygiene o According to the CDC, washing hands with soap and water is the best way to get rid of germs in most situations. If soap and water are not readily available, you can use an alcohol-based hand sanitizer that contains at least 60% alcohol. You can tell if the sanitizer contains at least 60% alcohol by looking at the product label. • Practice good respiratory hygiene – covering mouth and nose when coughing or sneezing, using tissues and disposing of them correctly. • Obtain immunizations recommended by healthcare providers to help avoid disease. • Early self-isolation of those feeling unwell, feverish and having other symptoms of flu. • Avoiding touching your eyes, nose or mouth. • Frequently disinfect all areas that are likely to have frequent hand contact (like doorknobs, faucets, handrails). 2.6. Client Meetings/Interactions Be aware of any restrictions or requirements that clients have in place regarding visiting client facilities or attending meetings. Verify with supervisor/project managers prior to visiting client facilities or meetings in person. Attachment A: COVID-19 Questionnaire for Onsite Workers The safety of our employees and their families, subcontractors, clients, and visitors is Heartland Construction’s highest priority. As the COVID-19 pandemic continues to evolve and spread, Heartland Construction will continue to monitor the CDC, WHO, and local agencies in order to provide up-to-date information to protect all of those in our community. To prevent the spread of COVID-19 and reduce the potential risk of exposure to our employees, subcontractors, and visitors, we request all personnel involved with on-site project-related work complete this assessment questionnaire. This questionnaire will be completed upon arrival to the jobsite and prior to conducting any job-related tasks. Your participation is important to help us take precautionary measures to protect you and everyone on our team. Date: Name: Company/Organization Email Address: Phone Number: Project Name: 1. Do you have signs of a fever or measured temperature above 100.4°F or greater, a dry cough, tiredness, or trouble breathing within the past 24 hours? Yes _____ No _____ 2. Have you had “close contact” with an individual diagnosed with COVID-19? “Close contact” means living in the same household as a person who has tested positive for COVID-19, caring for a person who has tested positive for COVID-19, being within 6 feet of a person who has tested positive for COVID-19 for 15 minutes or more, or coming in direct contact with secretions (for example, sharing utensils or being coughed on) from a person who has tested positive for COVID-19 while the person was symptomatic. Yes _____ No _____ 3. Have you, or anyone inside your residence been exposed to someone else who is currently being quarantined by a doctor or a local public health official? Yes _____ No _____ Be aware that your client may have additional requirements as well. Only personnel who answer “No” to all questions listed above will be granted site access. Copies of completed questionnaires are to be maintained onsite with the HASP and project documents. If the answer is “Yes” to question 1, please contact your Senior Superintendent and your HR Business Partner. Attachment B Hospital Route Map 2/17/2020 2822 NE Sunset Blvd to Valley Medical Center - Google Maps https://www.google.com/maps/dir/2822+Northeast+Sunset+Boulevard,+Renton,+WA/Valley+Medical+Center,+400+S+43rd+St,+Renton,+WA+98055/…1/2 Map data ©2020 Google 2000 ft Renton, WA 98056 2822 NE Sunset Blvd Continue to NE Sunset Blvd 1.Head southeast toward NE Sunset Blvd 2.Turn right toward NE Sunset Blvd 3.Turn left toward NE Sunset Blvd Continue on NE Sunset Blvd. Take I-405 S and WA-515 S to S 21st St 4.Turn right onto NE Sunset Blvd Pass by Pizza Hut (on the left) 5.Continue straight onto NE Park Dr/NE Sunset Blvd 6.Continue onto N Southport Dr 7.Turn left onto the Interstate 405 S ramp to Tacoma 55 s (0.1 mi) 98 ft 377 ft 121 ft 8 min (4.2 mi) 0.5 mi 0.4 mi 0.1 mi 0.4 mi Drive 5.8 miles, 13 min2822 NE Sunset Blvd to Valley Medical Center 2/17/2020 2822 NE Sunset Blvd to Valley Medical Center - Google Maps https://www.google.com/maps/dir/2822+Northeast+Sunset+Boulevard,+Renton,+WA/Valley+Medical+Center,+400+S+43rd+St,+Renton,+WA+98055/…2/2 These directions are for planning purposes only. You may nd that construction projects, trac, weather, or other events may cause conditions to differ from the map results, and you should plan your route accordingly. You must obey all signs or notices regarding your route. 400 S 43rd St, Renton, WA 98055 8.Merge onto I-405 S 9.Take exit 3 for WA-515/Talbot Road S 10.Use the left 2 lanes to turn slightly left onto WA- 515 S/Talbot Rd S (signs for Talbot Road S) Continue to follow WA-515 S Take Talbot Rd S to your destination 11.Turn right onto S 21st St 12.Continue onto Talbot Rd S 13.Turn right 14.Continue straight Valley Medical Center 1.8 mi 0.4 mi 0.6 mi 4 min (1.6 mi) 0.2 mi 1.3 mi 154 ft 131 ft Attachment C Emergency Rally Points Attachment D Safety Observation Forms Personal Factor: (1) Lack of skill or knowledge (2) Correct way takes more time/requires more effort (3) Shortcutting standard procedures is rewarded or appreciated (4) In past, did not follow procedures or acceptable practices and no incident occurred Job Factor: (5) Lack of or inadequate operational procedures or work standards (6) Inadequate communication of expectations or work standards (7) Inadequate tools or equipment Feedback Session Conducted By: Positive Comments Date Completed Questionable Observations/Root Cause Analysis Person Responsible Agreed Due Date Questionable Observation # Root Cause Analysis # Solution(s) To Prevent Potential Incident from Occurring Description of Task Observed and Background Information Name of Observee's Supervisor:Time: Results of Verification (were solutions done?) and Validation (were solutions effective?) Location/Project Name: Observer Name: Time: Date: Observee Name: Conclusions / Why the Questionable Items Occurred? Task Observed Date: Date: Date: Reviewed by (Supervisor): Approved by (Practice Safety Leader): HEARTLAND CONSTRUCTION SAFETY OBSERVATION FORM 1 PERSONAL PROTECTIVE EQUIPMENT Safe At-Risk Comments 1. Hearing Protection (e.g. Ear Plugs) 2. Head Protection (e.g. Hard Hat) 3. ANSI Rated Eye Protection (e.g. Safety Glasses) 4. Hand Protection (e.g. Kevlar Gloves) 5. Foot Protection (e.g. Safety Shoes) 6. Respiratory Protection 7. Fall Protection Inspected (e.g. harness) 8. ANSI Rated Reflective Vest/High Visibility Clothing 9. Other ( Specify) BODY USE AND POSITIONING Safe At-Risk Comments 10. Correct Body Use and Positioning When Lifting/Pushing/Pulling 11. Pinch Points/Moving Equipment - Hands/Body Clear 12. Mounts/Dismounts Using 3-Points of Contact 13. Other (Specify) WORK ENVIRONMENT Safe At-Risk Comments 14. Work/Walk Surface Free of Obstructions (e.g. tripping hazards) 15. Housekeeping/Storage 16. Defined and Secured (e.g. warning devices, barricades, cones, flags) 17. Suspended Load, Swing Radius & Lift Area is Barricaded 18. Safety Shut Down Devices 19. Proper Storage & Labeling /Disposal of Sample & Waste Materials 20. Cylinders Stored Upright, Secured, & Caps in Place 21. Manhole/vault Inspected for Hazards 22. Other (Specify) OPERATING PROCEDURES Safe At-Risk Comments 23. Job Planning (HASP reviewed, JSAs, etc.) 24. Fire Extinguishers Accessible and Inspections Current 25. Work Permit/Authorization to Work (Hot, Cold, LOTO, Confined Space) 26. JSA Reviewed & Followed 27. Hazard Assessment - Hazard Hunt 28. Interfaces with Other Functions (awareness with other personnel on site) 29. Operators Looking Behind Prior to Backing Up 30. Operators Wearing Seat Belts While Operating Equipment 31. Subsurface Structures Identified 32. Proper Trench Protective Equipment in Place 33. Adequate Egress Is Available for Excavation & Trench (within 25 ft. if depth is <4 ft.) 34. All Materials Set Back at Least 2 Feet From Edge of Trench/Excavation 35. Other (Specify) TOOLS/EQUIPMENT Safe At-Risk Comments 36. Hand Tools (Proper Equipment Selection, Condition, and Use) 37. Power Tools (Proper Equipment Selection, Condition, and Use) 38. Equipment, Including Heavy (Proper Equipment Selection, Condition, and Use) 39. Hoses Inspected 40. Required Monitoring Equipment Calibrated & Used 41. Ladders Setup Correctly & Inspected 42. Right Tools for the Job are Available and in Good Condition - No Fixed Open Blade Knifes (FOBKs) 43. Other (Specify) Total #00 HEARTLAND CONSTRUCTION SAFETY OBSERVATION FORM 2 Attachment E Incident Notification Report HEARTLAND CONSTRUCTION INCIDENT NOTIFICATION REPORT (To be completed immediately after an Injury, Illness, Incident or Significant Near Miss by Employee’s Supervisor and Employee involved) Incident Category Injury/Illness Near Miss/Loss Property Damage Other 1 Incident Location: 2 Project #: 3 Client: 4 Date Incident Occurred: Time: 5 Date Incident Reported: Time: Heartland Construction Employee Information 6 Name: Phone: 7 Office: Address: 8 Supervisor Name: Phone: 9 Title or Occupation: 10 Sector/Practice: Incident Description 11 Task Performed/Description of Incident: 12 Conditions at the Time of Incident (weather, lighting, etc.): 13 Description of Property Damage: Employee Injury or Illness Description 14 Describe the Injury or Illness: 15 First Aid/Medical Treatment Administered: 16 Was Supervisor Contacted? Yes No 17 Name of Doctor’s Office, Clinic or Hospital: 18 Address: Phone: HEARTLAND CONSTRUCTION INCIDENT NOTIFICATION REPORT (To be completed immediately after an Injury, Illness, Incident or Significant Near Miss by Employee’s Supervisor and Employee involved) Subcontractor Involvement 19 Was a subcontractor involved? Yes No 20 Name of Company: 21 Address: 22 Contact Name: Phone: 23 Description of the Incident: Witness Information 24 Were there witnesses to the incident? Yes No 25 Name(s) Address(es) Number(s) Immediate Corrective Actions 26 Describe the Immediate Corrective Actions Taken: Client Notification 27 Is there a client incident notification requirement? Yes No 28 Contact Name 29 Date of Notification: Time: 30 Notification Method: Supervisor: Signature: Date: Employee: Signature: Date: Solera – DevCo, LLC Page 42 H. Engineering Calculations 1. Sediment Pond Sizing KPFF Consulting Engineers, Inc Solera, Renton, WA KPFF Project No. 1700659 Jul-21 StormShed Calculations - TESC Calculations for TESC Pond Sizing Stormshed Inputs: 2-year 24-hour Event Precipitation = 2 in 10-year 24-hour Event Precipitation = 2.9 in 100-year 24-hour Event Precipitation = 3.9 in 10-yr Pervious CN =87 Impervious CN =98 Method =SBUH Rain Type =TYPE 1A Pervious Area =4.10 acres Impervious Area =4.10 acres Total Area = 8.20 acres Pervious Tc =5 min (assumed) Impervious Tc =5 min (assumed) StormShed Results: Runoff Rate 24-hr Event Site 4.51 cfs 2,024 gpm Min. Required Storage =32,390 cf 242,280 gal Req'd Volume 1199.408171 CY Pond Volume 16,623 CY StormShed Unmitigated Flows (15 min time step): 2 yr 2.636 cfs 10 yr 4.5107 cfs 100 yr 6.623 cfs 2021 King County Surface Water Design Manual 2017 Renton Surface Water Design Manual, D.2.1.5.2 Sediment Pond Surface Area 9382.256 sf at top of riser From Renton Surface Water Design Manual Appendix D Page D-49, SA = 2xQ10/0.00096 OR 2080 sf per cfs of inflow L:W Ratio 3 1 Between 3:1 and 6:1 Length 167.7699854 ft Width 55.92332847 ft Area 9382.256 sf Riser Pipe Size Head 1 ft Riser 15 in From KC SWDM Figure 5.1.4.H: Riser Inflow Curves, 10-year Q Emergency Overflow Spillway 100 year Q 6.6225 cfs Head 1 ft Length -0.336915888 ft Minimum 6' Use 6' Length calculated using SWDM Section 5.1.1.2 Eq (5-3) Dewatering Orifice Area 9382.256 actual surface area Head 3.5 Ao 0.084427976 sf Diameter 3.93424909 in Must be 1", tubing 2" larger than orifice 1" Min Good Equations found on page D-50 of the Renton SWDM Dewatering Tube Diameter 6 in Min. 2" larger than dewatering orifice, Renton SWDM p. D-50 DESIGN CALCULATIONS: Overflow Spillway, Outlet Sizing, Riser TESC drainage basin area defined by limits of construction Precipitation values obtained Section 3.2 Isopluvials in the King County Surface Water Design Manual StormShed was used to calculate runoff rate for the 10yr design storm for the TESC Basin. The minimum required storage area will be provided in the detention pond 10-yr 2021-07-07 TESC Ponds.xlsx Solera 1 of 1 8/10/2021 | 4:22 PM