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HomeMy WebLinkAboutF_SWPPP_C18006309.pdf04Construction Stormwater General Permit Stormwater Pollution Prevention Plan (SWPPP) for Prologis Renton 9 Prepared for: Prologis Permittee / Owner Developer Operator / Contractor Prologis Prologis Prologis City of Renton Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number TBD TBD TBD SWPPP Prepared By Name Organization Contact Phone Number S Nelson Innova Architects 253-572-4903 SWPPP Preparation Date 4/2/2019 Project Construction Dates Activity / Phase Start Date End Date Demolition/Reconstruction 6/25/19 6/25/20 DEVELOPMENT ENGINEERING rnair 06/27/2019 Page 1 of 90 Table of Contents 1 Project Information .............................................................................................................. 4 1.1 Existing Conditions ...................................................................................................... 4 1.2 Proposed Construction Activities .................................................................................. 4 2 Construction Stormwater Best Management Practices (BMPs) ........................................... 6 2.1 The 13 Elements .......................................................................................................... 6 2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits ........................................ 6 2.1.2 Element 2: Establish Construction Access ............................................................ 7 2.1.3 Element 3: Control Flow Rates ............................................................................. 8 2.1.4 Element 4: Install Sediment Controls .................................................................... 9 2.1.5 Element 5: Stabilize Soils ....................................................................................10 2.1.6 Element 6: Protect Slopes....................................................................................11 2.1.7 Element 7: Protect Drain Inlets ............................................................................12 2.1.8 Element 8: Stabilize Channels and Outlets ..........................................................13 2.1.9 Element 9: Control Pollutants ...............................................................................14 2.1.10 Element 10: Control Dewatering ..........................................................................16 2.1.11 Element 11: Maintain BMPs .................................................................................17 2.1.12 Element 12: Manage the Project ..........................................................................18 2.1.13 Element 13: Protect Low Impact Development (LID) BMPs .................................20 3 Pollution Prevention Team .................................................................................................21 4 Monitoring and Sampling Requirements ............................................................................22 4.1 Site Inspection ............................................................................................................22 4.2 Stormwater Quality Sampling ......................................................................................22 4.2.1 Turbidity Sampling ...............................................................................................22 4.2.2 pH Sampling ........................................................................................................24 5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies .........................25 5.1 303(d) Listed Waterbodies ..........................................................................................25 5.2 TMDL Waterbodies .....................................................................................................25 6 Reporting and Record Keeping ..........................................................................................26 6.1 Record Keeping ..........................................................................................................26 6.1.1 Site Log Book ......................................................................................................26 6.1.2 Records Retention ...............................................................................................26 6.1.3 Updating the SWPPP ...........................................................................................26 6.2 Reporting ....................................................................................................................27 6.2.1 Discharge Monitoring Reports ..............................................................................27 6.2.2 Notification of Noncompliance ..............................................................................27 Page 2 of 90 List of Tables Table 1 – Summary of Site Pollutant Constituents ..................................................................... 4 Table 2 – Pollutants ..................................................................................................................14 Table 3 – pH-Modifying Sources ...............................................................................................15 Table 4 – Dewatering BMPs ......................................................................................................16 Table 5 – Management .............................................................................................................18 Table 6 – BMP Implementation Schedule .................................................................................19 Table 7 – Team Information ......................................................................................................21 Table 8 – Turbidity Sampling Method ........................................................................................22 Table 9 – pH Sampling Method .................................................................................................24 List of Appendices Appendix/Glossary A. Site Map 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 Page 3 of 90 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 Page 4 of 90 1 Project Information Project/Site Name: Prologis Renton 9 Street/Location: 601 Monster Road SW City: Renton State: WA Zip code: Subdivision: N/A Receiving waterbody: Regional Stormwater Facility 1.1 Existing Conditions Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage: 10.39 acres Offsite ROW Imp. 0.28 acres Disturbed acreage: 9.35 acres Existing structures: 3.37 acres Landscape topography: 1.45 acres Drainage patterns: One Basin Existing Vegetation: About 1.04 acres of existing landscape will not be disturbed Critical Areas (wetlands, streams, high erosion risk, steep or difficult to stabilize slopes): Steep slope located on the south side of the site which will be placed in a dedicated protection easement List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: Regional Stormwater Facility then to the Black River Category 5 Table 1 includes a list of suspected and/or known contaminants associated with the construction activity. Table 1 – Summary of Site Pollutant Constituents Constituent (Pollutant) Location Depth Concentration See DOE's Cleanup Site ID 11481 AOC1 & AOC2 4 to 8 feet Trichloroethylene (TCE) AOC4 (NE bldg. corner) 6.5 to 14 feet 188 (µg/m3) 1.2 Proposed Construction Activities Description of site development (example: subdivision): Existing commercial site/building redevelopment; new building and site improvements. Description of construction activities (example: site preparation, demolition, excavation): Page 5 of 90 Site prep, demolition,preload; excavation, utility installation and reconstruction Description of site drainage including flow from and onto adjacent properties. Must be consistent with Site Map in Appendix A: The entire site flows to an existing off-site regional stormwater facility. A portion of the site flows onto Monster Road which drains to the same facility. A small vegetated portion of the developed right of way along the east side of the project site drains onto the site. Likewise a small paved portion of the property along the west side will sheet flow uncaptured. This is true in the existing and developed condition. Otherwise the majority of the site will be captured and conveyed via tightline to the regional private facility. Description of final stabilization (example: extent of revegetation, paving, landscaping): New Building, parking and landscaping. Site will continue to flow to the existing off-site regional stormwater facility Contaminated Site Information: Proposed activities regarding contaminated soils or groundwater (example: on-site treatment system, authorized sanitary sewer discharge): The site has been assigned Cleanup Site ID 11481 by the Dept of Ecology. Three Areas of Concern (AOC1, AOC2, AOC4) were indicated by Floyd | Snider in their 2017 Phase 1 ESA which necessitate further action. AOC4 requires excavation and removal of the contaminated material and has been addressed in the Floyd | Snider Fill and Grade Plans which have been submitted to the City. AOC1 and AOC2 have been addressed in the site development plans prepared by Innova Architects. Any soil excavated in these area will be directly loaded into trucks and hauled to a Subtitle D facility. Additionally, all stormwater and groundwater that enters these areas during excavation will be pumped to a portable sediment tank, filtered and pumped into the sanitary sewer system. Page 6 of 90 2 Construction Stormwater Best Management Practices (BMPs) 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. 2.1 The 13 Elements 2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits List and describe BMPs: Locate property lines, silt fencing, orange construction fencing to indicate areas to be protrected (steep slopes will not be disturbed). Installation Schedules: Prior to construction activity Inspection and Maintenance plan: Inspect daily and maintain as needed Responsible Staff: Contractor and CESCL Page 7 of 90 2.1.2 Element 2: Establish Construction Access List and describe BMPs: A standard rock construction entrance will be implermented and has been outlined on the Erosion Control plans. Installation Schedules: Prior to to construction activity. Inspection and Maintenance plan: In accordance with the approved plans, jurisdictional requirements and as requested per CESCL Responsible Staff: Contractor and CESCL Page 8 of 90 2.1.3 Element 3: Control Flow Rates Will you construct stormwater retention and/or detention facilities? Yes No Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retention, porous pavement) to control flow during construction? Yes No List and describe BMPs: Temporary flow control, during construction, will be addressed by a sediment pond, sediment trap, silt fencing and straw wattles. Sediment trap and pond sizing calculations have been provided in Appendix H of this report. As part of this project the owner will be sawcutting the existing concrete slab in order to save and reuse as much of the existing concrete floor as is practicable to be used for the new structure. Since the existing concrete slab is level, direct conveyance and capture of storm water from the slab is not feasible. Minimal sediment is expected to be on the slab therefore we have proposed the placement of straw wattles around the permiter of the slab to minimize runoff onto the surrounding soils. Additionally, we are proposing to leave an opening near the south- east corner of the slab where stormwater would drain to a rip rap pad and drain into the existing storm system. Please refer to the Civil Plans or the Site Plan section of this report for more information. Permanent stormwater runoff control, for this parcel, is addressed by an existing private regional stormwater facility. Water Quality is being addressed using stormwater modular wetland and oil water seperator. Installation Schedules: Temporary BMP's to be installed prior to construction work Inspection and Maintenance plan: No maintenance is expected, but the CESCL should inspect the existing facility Responsible Staff: CESCL Page 9 of 90 2.1.4 Element 4: Install Sediment Controls List and describe BMPs: Silt fencing, bioswales, wheel wash facilities if warranted, Temporary Construction Stormwater Sedimentation Tank for stormwater that comes into contact with contaminated soils. Installation Schedules: Install prior to construction work. Inspection and Maintenance plan: Inspect daily or as directed by the on-site CESCL. Responsible Staff: Contractor and CESCL Page 10 of 90 2.1.5 Element 5: Stabilize Soils West of the Cascade Mountains Crest Season Dates Number of Days Soils Can be Left Exposed During the Dry Season May 1 – September 30 7 days During the Wet Season October 1 – April 30 2 days Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. Anticipated project dates: Start date: 6/25/2019 End date: 6/25/2020 Will you construct during the wet season? Yes No List and describe BMPs: Silt fencing, plastic covering, straw mulch, sediment pond, sediment trap, straw wattles, portable sediment tank and filter system pumped to sewer for runoff that contacts contaminated soils. Installation Schedules: Prior to construction Inspection and Maintenance plan: Daily or as directed by the on-site CESCL Responsible Staff: Contractor and CESCL Page 11 of 90 2.1.6 Element 6: Protect Slopes Will steep slopes be present at the site during construction? Yes No The site contains existing steep slopes along the southern property line. These steep slopes will not be disturbed by the construction and are located outside of the clearing area. List and describe BMPs: Orange construction fencing. Installation Schedules: Prior to construction. Inspection and Maintenance plan: As directed by the CESCL Responsible Staff: Contractor and CESCL Page 12 of 90 2.1.7 Element 7: Protect Drain Inlets List and describe BMPs: Catch Basin Filters, wattles Installation Schedules: Prior to Construction Inspection and Maintenance plan: As required by jurisdictional requirements or as directed by the on-site CESCL Responsible Staff: Contractor and CESCL Page 13 of 90 2.1.8 Element 8: Stabilize Channels and Outlets 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: Rip rap pads will be installed at inlet and outlet locations on sediment pond and trap. Installation Schedules: Prior to construction activity Inspection and Maintenance plan: As required by jurisdictional requirements or as directed by the on-site CESCL Responsible Staff: Contractor and CESCL Page 14 of 90 2.1.9 Element 9: Control Pollutants The following pollutants are anticipated to be present on-site: Table 2 – Pollutants Pollutant (List pollutants and source, if applicable) Sediment during reconstruction Building debris during demolition will be transported to an approved disposal facility Pollutants managed by remedial action work plan (AOC4) - See Floyd Snider Plans Concrete Handling Pollutants in AOC1 and AOC2 Sawcutting List and describe BMPs: Sediment fencing, wattles, sediment pond, sediment trap, plastic covering, and other as directed by the on-site CESCL in conjunction with the Floyd Snider Plans Installation Schedules: Prior to and during site construction Inspection and Maintenance plan: As required by jurisdictional requirements or as directed by the on-site CESCL Responsible Staff: Contractor and CESCL Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? Yes No List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Will wheel wash or tire bath system BMPs be used during construction? Yes No List and describe BMPs: Standard Construction Entrance Installation Schedules: Prior to Construction or as directed by the on-site CESCL Inspection and Maintenance plan: As required by jurisdictional requirements or as directed by the on-site CESCL Responsible Staff: Contractor and CESCL Will pH-modifying sources be present on-site? Page 15 of 90 Yes No If yes, check the source(s). 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 Concrete pumping and mixer washout waters Recycled concrete Recycled concrete stockpiles Other (i.e., calcium lignosulfate) [please describe: ] Describe BMPs you will use to prevent pH-modifying sources from contaminating stormwater. List and describe BMPs: Concrete Washout Area, Sediment Pond, Sediment Trap Installation Schedules: Prior to connstruction or as directed by the on-site CESCL Inspection and Maintenance plan: Daily or as directed by the on-site CESCL 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. Will uncontaminated water from water-only based shaft drilling for construction of building, road, and bridge foundations be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters? Yes No N/A If yes, provide BMPs to contain the wastewater during infiltration. 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). List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: Contractor and CESCL Page 16 of 90 2.1.10 Element 10: Control Dewatering Control and disposal for the dewatering under the remedial action (AOC4) will be defined by the plans and reports prepared by Floyd Snider. Dewatering methods for AOC1 and AOC2 have been addressed in this report and the civil plans. Check treatment of disposal option for dewatering water, if applicable: 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) X Utilize the proposed on-site sedimentation facility List and describe BMPs: Stormwater and groundwater that enters AOC1 and AOC2 during excavation will be pumped to a portable sediment tank, filtered and pumped into the sanitary sewer system. Installation Schedules: As needed or as directed by the on-site CESCL Inspection and Maintenance plan: Dailiy of as directed by on-site CESCL Responsible Staff: Contractor and CESCL Page 17 of 90 2.1.11 Element 11: Maintain BMPs All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW). Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be returned to conditions specified in the construction documents. Page 18 of 90 2.1.12 Element 12: Manage the Project 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 Design the project to fit the existing topography, soils, and drainage patterns Emphasize erosion control rather than sediment control Minimize the extent and duration of the area exposed Keep runoff velocities low Retain sediment on-site Thoroughly monitor site and maintain all ESC measures Schedule major earthwork during the dry season Other (please describe) Page 19 of 90 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] Initial start of construction Silt Fencing 6/25/2019 Dry and maintain during Interception swale 10/1/19 Wet construction Construction Entrance 6/25/2019 Dry Catch Basin Filters 6/25/19 Dry Wattles 6/25/19 Dry Sedimentation Tank Facilities 6/25/19 Dry Sediment Pond 10/1/19 Wet Sediment Trap 10/1/19 Wet Earth Berms 10/1/19 Wet Page 20 of 90 2.1.13 Element 13: Protect Low Impact Development (LID) BMPs Low Impact BMP’s are not proposed for this project due to the underlying fill soils. No infiltration is recommended by the geotechnical engineer. Page 21 of 90 3 Pollution Prevention Team Table 7 – Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD [Insert Number] Resident Engineer TBD Emergency Ecology Contact Spills Manager - Rob Walls 425-649-7130 Emergency Permittee/ Owner Contact TBD Non-Emergency Owner Contact TBD Monitoring Personnel TDB Ecology Regional Office Bellevue Office 425-649-7000 Page 22 of 90 4 Monitoring and Sampling Requirements 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. 4.1 Site Inspection 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. 4.2 Stormwater Quality Sampling 4.2.1 Turbidity Sampling 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: As directed by the on-site CESCL Table 8 – Turbidity Sampling Method 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. Page 23 of 90 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.  Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, Yakima): (509) 575-2490 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/CRO_nerts_online.html  Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/ERO_nerts_online.html  Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish, Whatcom): (425) 649-7000 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/NWRO_nerts_online.html  Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/SWRO_nerts_online.html 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. Page 24 of 90 4.2.2 pH Sampling pH monitoring is required for “Significant concrete work” (i.e., greater than 1000 cubic yards poured concrete over the life of the project). The use of recycled concrete or 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: pH meter or as directed by the on-site CESCL Table 9 – pH Sampling Method pH meter pH test kit Wide range pH indicator paper Page 25 of 90 5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies 5.1 303(d) Listed Waterbodies Circle the applicable answer, if necessary: Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? Yes No List the impairment(s): Category 5 waters Black River; impairments are Dissolved Oxygen, Bioassessment and Bacteria If yes, discharges must comply with applicable effluent limitations in S8.C and S8.D of the CSWGP. 5.2 TMDL Waterbodies Waste Load Allocation for CWSGP discharges: Not Applicable Describe the method(s) for TMDL compliance: List and describe BMPs: During construction storm water will be collected and pumped to Bakers Tanks, filtered and pumped into the natural release point for the site and flow to the regional facility. 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 F. Page 26 of 90 6 Reporting and Record Keeping 6.1 Record Keeping 6.1.1 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  Sample logs 6.1.2 Records Retention 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. 6.1.3 Updating the SWPPP The SWPPP will be modified if:  Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site.  There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine additional or modified BMPs are necessary for compliance. An updated timeline for BMP implementation will be prepared. Page 27 of 90 6.2 Reporting 6.2.1 Discharge Monitoring Reports 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. Or Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period the DMR will be submitted as required, reporting “No Discharge”. The DMR due date is fifteen (15) days following the end of each calendar month. DMRs will be reported online through Ecology’s WQWebDMR System. To sign up for WQWebDMR go to: http://www.ecy.wa.gov/programs/wq/permits/paris/webdmr.html 6.2.2 Notification of Noncompliance 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 Page 28 of 90  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 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. Page 29 of 90 Appendix/Glossary A. Site Map Page 30 of 90 Page 31 of 90 Page 32 of 90 Page 33 of 90 Page 34 of 90 B. BMP Detail Page 35 of 90 Page 36 of 90 Page 37 of 90 Page 38 of 90 Page 39 of 90 Page 40 of 90 Page 41 of 90 Page 42 of 90 Page 43 of 90 Page 44 of 90 Page 45 of 90 Page 46 of 90 C. Correspondence Page 47 of 90 Page 48 of 90 Page 49 of 90 Page 50 of 90 Page 51 of 90 Page 52 of 90 D. Site Inspection Form Page 53 of 90 Page 54 of 90 Page 55 of 90 Page 56 of 90 Page 57 of 90 Page 58 of 90 E. Construction Stormwater General Permit (CSWGP) Page 59 of 90 Page 60 of 90 Page 61 of 90 F. 303(d) List Waterbodies / TMDL Waterbodies Information Not Applicable Page 62 of 90 G. Contaminated Site Information Page 63 of 90 Page 64 of 90 Page 65 of 90 Page 66 of 90 Page 67 of 90 Page 68 of 90 Page 69 of 90 Page 70 of 90 Page 71 of 90 Page 72 of 90 Page 73 of 90 Page 74 of 90 Page 75 of 90 Page 76 of 90 Page 77 of 90 Page 78 of 90 Page 79 of 90 Page 80 of 90 Page 81 of 90 H. Engineering Calculations Page 82 of 90 SEDIMENT TRAP SIZING CALCULATIONS - NORTH This sediment trap has been sized to address the expected flow from the developed 10-year recurrence interval at a 15-minute timestep. The design is conservative as we have based it upon the 10-year recurrence and the entire Developed Drainage Basin A plus a portion of the future roof area. It is not feasible to collect all of the Developed Basin A so a portion of this area will be controlled utilizing silt fence, straw wattles, and catch basin inserts. WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: TESC Dev AplusRoof Site Name: Monster Road Site Address: 601 Monster Rd City : Renton Report Date: 3/29/2019 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.00 Version Date: 2018/03/02 Version : 4.2.14 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE Name : DEV A Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat .19 Pervious Total 0.19 Impervious Land Use acre ROADS FLAT 0.42 Impervious Total 0.42 Basin Total 0.61 Element Flows To: Surface Interflow Groundwater Page 83 of 90 ___________________________________________________________________ Name : Future Roof Area Bypass: No GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 1 Impervious Total 1 Basin Total 1 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : DEV A Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat .19 Pervious Total 0.19 Impervious Land Use acre ROADS FLAT 0.42 Impervious Total 0.42 Basin Total 0.61 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ Name : Future Roof Area Bypass: No GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 1 Impervious Total 1 Basin Total 1 Element Flows To: Surface Interflow Groundwater Page 84 of 90 ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration ___________________________________________________________________ Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.19 Total Impervious Area:1.42 ___________________________________________________________________ Mitigated Landuse Totals for POC #1 Total Pervious Area:0.19 Total Impervious Area:1.42 ___________________________________________________________________ Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.553588 5 year 0.703418 10 year 0.805684 25 year 0.938816 50 year 1.041034 100 year 1.145993 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.553588 5 year 0.703418 10 year 0.805684 Flow for Sediment Trap Sizing 25 year 0.938816 50 year 1.041034 100 year 1.145993 ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Page 85 of 90 Size Sediment Trap (Renton) Prologis Renton 9 Q2 = 0.81 cfs (Peak Flow , 10-year recurrence, 15-min time step) Vsed = 0.00096 ft/s (Particle Settling Velocity) FS = 2 (Factor of Safety) SA = 2*Q2 / Vsed =1679.17 sf, (Surface area at Weir) Surface Area at Weir Provided = 1,751 sf Berm Elev. 28.0 Weir Elev. 27.0 2.5' Settling Zone Elev. 24.5 1.0' Sediment storage Elev. 23.5 Surface Area = FS(Q2/Vsed) (Per 2017 City of Renton Surface Water Manual Section D.2.1.5.1 Sediment Trap) Page 86 of 90 SEDIMENT POND SIZING CALCULATIONS – SOUTH (DEVELOPED BASIN B CONVEYANCE CALC) This sediment pond has been sized to address the expected flow from the developed 10-year recurrence interval at a 15-minute timestep. The design is based upon the 10-year recurrence and the entire Developed Drainage Basin B. In addition, the project will install silt fence, straw wattles, and catch basin inserts to additionally minimize sediment laden water from leaving the site. WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: monsterProl DevBConv Site Name: Monster Road Site Address: 601 Monster Rd City : Renton Report Date: 2/25/2019 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.00 Version Date: 2018/03/02 Version : 4.2.14 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE Name : DEV B Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Steep 1.04 C, Lawn, Flat .86 Pervious Total 1.9 Page 87 of 90 Impervious Land Use acre ROADS FLAT 2.92 SIDEWALKS FLAT 0.03 Impervious Total 2.95 Basin Total 4.85 Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : DEV B Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Steep 1.04 C, Lawn, Flat .86 Pervious Total 1.9 Impervious Land Use acre ROADS FLAT 2.92 SIDEWALKS FLAT 0.03 Impervious Total 2.95 Basin Total 4.85 Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.9 Total Impervious Area:2.95 Mitigated Landuse Totals for POC #1 Total Pervious Area:1.9 Total Impervious Area:2.95 Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 1.203242 5 year 1.543091 10 year 1.776711 25 year 2.082543 50 year 2.318512 Page 88 of 90 100 year 2.561743 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 1.203242 5 year 1.543091 10 year 1.776711 Flow for Sediment Pond Sizing 25 year 2.082543 50 year 2.318512 100 year 2.561743 ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Page 89 of 90 Size Sediment Pond (Renton) Prologis Renton 9 Surface Area = FS(Q2/Vsed) Sub Basin Dev B area flowing to proposed sediment pond. Q10 =1.777 cfs (Peak Flow Developed , 10-yr recurrence, 15-min time step) Vsed = 0.00096 ft/s (Particle Settling Velocity) FS = 2 (Factor of Safety) SA = 2*Q2 / Vsed =3702.08 sf, (Surface area at Top of Riser) (Per 2017 City of Renton Surface Water Manual Section D.2.1.5.2 Sediment Pond) Elev. 28.0 berm Surface Area at Top of Riser Provided = 4511 Elev. 27.0 overflow weir Elev. 26.0 top of riser 2.5' Settling Zone Elev. 23.5' 1' Sediment storage Elev. 22.5' Principal Spillway (Riser) Diameter Sizing (Peak Flow Developed, 10-yr recurrence, 15-min time step) Q10 = 1.777 cfs (Peak Flow, 10yr Developed ) H = 1.00 ft (Head measured from Top of Riser to Crest of emergency spillway) Diameter = 8"= 12.0 Q = c[(pi)d^2/4][(2gh)^1/2] d =12.00 IN. Orfice diameter c =0.62 Sharp edged orfice constrant g =32.2 Ft/Sec^2 gravitation constant h =1.000 FT. head on orfice Q = 3.91 CFS Principal Spillway Diameter is Acceptable Dewatering Orifice Sizing Ao =(As(2*h)0.5)/(10.6*3600*T*g0.5) Ao= 0.001885 (Orifice Area , Square Feet ) As= 3702.08 (Pond surface Area, Square Feet) h =3.5 (Height of Riser in Feet) T = 24 (Dewatering Time, HRs g = 32.2 (Acceleration of gravity ft/sec 2) Dewatering Orifice Diameter D = 24 * (Ao / 3.14)^.5 = 0.59 in (9/16" orifice) Q = ca 2gh