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HomeMy WebLinkAboutRS_Drainage_Report_211201_v1Structural + Civil Engineers 1301 Fifth Avenue, Suite 3200 Seattle, Washington 98101-2699 T: 206 292 1200 F: 206 292 1201 December 1, 2021 12 Seahawks Way Renton, Washington STORM DRAINAGE DESIGN Storm Drainage Design Virginia Mason Athletic Center, Renton, Washington 1 1 – PROJECT OVERVIEW The Virginia Mason Athletic Center (VMAC) was constructed in Renton roughly 12 years ago to be the home and practice facility for the Seattle Seahawks. The site is located at 12 Seahawks Way, Renton, Washington, and is adjacent to Lake Washington. See attached Figure 1: Technical Information Report (TIR) Worksheet. See Figure 2: Site Location below. Figure 2: Site Location VMAC includes three natural turf practice fields that require annual maintenance, including importing sand for topping off and leveling of the fields. As a result of the annual maintenance, the field elevations have become elevated and require the removal of the annually imported sand to bring them back in vertical alignment with the original condition. The maintenance regime for the fields will roughly follow the schedule below and repeat approximately every 10 years. LAKE WASHINGTON PROJECT LOCATION Storm Drainage Design Virginia Mason Athletic Center, Renton, Washington 2 ANNUAL MAINTENANCE PRACTICES (APPROXIMATELY DURING YEARS 1 THROUGH 9) Perform maintenance to include aeration, topdressing, and other measures to maintain vertical drainage of playing surface. Estimated quantities include: ◼ Aeration: Removal of approximately 60 cubic yards (CY) of material 2-5 times per year ◼ Topdressing: Application of approximately 45 CY of clean, compatible sand 9-12 times per year CORRECTIVE MAINTENANCE (APPROXIMATELY IN YEAR 10) Remove imported sand and organic matter built up over the previous 9 years. This process maintains vertical drainage and removes perimeter sloping from imported topdressing sand. Quantities are variable but the estimated accumulation is approximately 500 CY per year. No work will be performed on existing site infrastructure, except removals of the imported sand and organic matter noted above. PROPOSED CONSTRUCTION SEQUENCE FOR CORRECTIVE MAINTENANCE An estimated 5,340 cubic yards of imported sand and organic matter will be excavated and removed from the existing engineered athletic fields with the use of a barge in Lake Washington for exporting the soils from the site. Earthwork and Grading: ◼ Remove the existing turf and soil material from the field with pavement grinder equipment (by tilling and laser leveling the fields) and transport the material to a barge at the northwest corner of the fields (see Barge Operation below for additional context). ◼ Compact the remaining soil/sand to match the original grades. ◼ Additional earthwork and grading context: — The natural turf fields at VMAC are sand based, engineered athletic fields that were constructed in 2007. — No new fill will be imported; this project only includes removing the material that has accumulated to the playing surface over the last 14 years. — Soil Description: All excavated soil to be transported off site is clean, imported, sand material with a small amount of organic accumulation. No native soils will be disturbed during this process. ◼ Total timeframe for excavation will be 5-7 days. Barge Operation: ◼ To avoid further adding to local traffic along the I-405 corridor during WSDOT/SoundTransit construction, as well as bike/pedestrian use of the Eastside Rail Corridor Trail, the general contractor has recommended transporting excavated material via barge for maximum efficiency and shortest project timeline. ◼ The barge will be operated by a professional material handling/trucking/transport company that has been utilizing barge transportation for over 30 years. Storm Drainage Design Virginia Mason Athletic Center, Renton, Washington 3 ◼ A barge ramp will occupy a 16-foot-wide section of our shoreline. The ramp and steel plating will create access for small dump trucks to haul material to the barge. Trucks will not be driving in or on the existing shoreline soils. ◼ Existing shoreline plants will be transplanted from the ramp zone and re installed after the project is completed. Re-vegetation will occur as needed. ◼ Total timeframe for barge operation will be 5-7 days. Turf Install: ◼ Place new natural turf sod over the roughly 248,000 square feet of regraded fields. ◼ After placement of the new natural turf sod, remove and replace the artificial turf strip along the southeasterly edge of the fields. Temporary Erosion & Sediment Controls : ◼ Compost filter socks, stone bag inlet protection, and sandbag barriers will be used to prevent sediment-laden waters from leaving the project limits. Native and shoreline soils will not be disturbed during this project. See Section 8 – CSWPPP Analysis and Design for more information. All existing storm drainage patterns will be maintained in their existing condition. No storm drainage infrastructure is proposed to be modified or altered. No off-site flows will be impacted by this project. Most of the sections of a typical Technical Information Report do not apply to this project; as such, only sections 1, 2, 8, and 9 are included in the text. 2 – CONDITIONS AND REQUIREMENTS SUMMARY This project is an athletic field maintenance project that will restore the fields to their original condition and has no site improvement requirements. Many of the City of Renton Core Requirements do not apply to this project. Only Core Requirements #5 and #7 apply, see below for a summary of each requirement: ◼ Discharge at Natural Location: Does not apply, the work will not touch the existing storm drainage systems and therefore will keep existing outfalls. ◼ Off-Site Analysis: Does not apply, there are no upstream flows to storm systems of the field drainage system and the fields drain directly to Lake Washington. There will be no change to flow regimes or pipes so there will also be no impact to downstream conditions. This project meets Exemption Criteria No. 1. ◼ Flow Control Facilities: Does not apply, the site has direct discharge(s) to Lake Washington via the field drainage storm system so there are no downstream systems that would be impacted. In addition, there will be no change to flow regime. This project meets Exemption Criteria No. 2. ◼ Conveyance System: Does not apply, there will be no change to flow regime and the existing system has capacity with direct discharge to Lake Washington. Storm Drainage Design Virginia Mason Athletic Center, Renton, Washington 4 ◼ Construction Stormwater Pollution Prevention: Applies, there will be exposed sand on the vertically draining fields. See Section 8 – CSWPP Analysis and Design below. ◼ Maintenance and Operations: Does not apply, there will be no changes to existing facilities so there should be no changes to the existing operations and maintenance manual prepared for the original project. ◼ Financial Guarantees and Liability: Applies, the project will need to post a surety device in the amount identified in the Bond Quantity Worksheet for the erosion control measures. See Section 9 – Bond Quantities, Facility Summaries, And Declaration of Covenant. ◼ Water Quality Facilities: Does not apply, the field section was constructed with a thicker layer of sand (equivalent to a sand filter), there will be no new/replaced impervious surface and no new PGPS. This project meets Exemption Criteria No. 1. ◼ On-Site BMPs: Does not apply; there is new impervious surface, no new pervious surface, and no replaced impervious surface. This project meets Exemption Criteria No. 1. Similar to the City of Renton Core Requirements, none of the City of Renton Special Requirements apply to this project. 8 – CSWPPP ANALYSIS AND DESIGN ESC PLAN ANALYSIS AND DESIGN (PART A) The overall approach for the ESC Plan is to use compost filter socks, sandbag barriers and stone bag inlet protection to prevent sediment-laden water from leaving the project area as shown on the site improvements (temporary erosion and sediment control) plans. Compost filter socks will be used where the socks can be staked to the ground. Sandbag barriers will be placed on hardscape instead of compost filter socks where the socks cannot be staked. Sandbag inlet protection will be placed at inlets to prevent sediment-laden water from entering the existing storm drain infrastructure. The following nine measures required in Core Requirement #5 and their applicability are discussed below: ◼ Clearing Limits: Clearing limits will be delineated by the existing sidewalk and containment curb of the fields. ◼ Cover Measures: No cover measures are proposed, no areas are anticipated to be unworked for more than 2 days. ◼ Perimeter Protection: Perimeter protection, as noted in the section summary above, will be installed. ◼ Traffic Area Stabilization: No traffic area stabilization is required; construction vehicles will not drive on un-stabilized work areas and will drive directly from the fields to the barge via the barge ramp. Additionally, trucks will not be driven in or on the existing shoreline soils. ◼ Sediment Retention: No sediment traps or basins are required; no off-site discharge of surface water is anticipated. Inlet protection will be installed on all storm-drain inlets within and/or near the project limits Section D.2.1.5.3 of the Renton Surface Water Design Manual. ◼ Surface Water Collection: No surface water collection is required; no offsite discharge of surface water is anticipated. Storm Drainage Design Virginia Mason Athletic Center, Renton, Washington 5 ◼ Dewatering Control: No dewatering control is required; no dewatering activities are proposed with this project. ◼ Dust Control: No dust control is required; no dust generation is anticipated during construction activities. ◼ Flow Control: No flow control is required; the site imperviousness is not proposed to change. SWPPS PLAN DESIGN (PART B) The only pollution prevention activity for this project is tilling and excavation of the existing turf fields. Compost socks, sandbag barriers, and stone bag inlet protection are proposed BMPs to prevent stormwater pollution. A Conceptual Stormwater Pollution Prevention and Spill Plan has been prepared for this project, see Appendix A: CSWPPS for more information. 9 – BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT City of Renton Core Requirement #7 applies to this project. A Bond Quantities Worksheet is included in Appendix B: Bond Quantities. Flow Control and Water Quality Summaries and Declaration of Covenants for Flow Control and BMPs are not required for this project as no flow control or Permanent BMP facilities are proposed. CITY OF RENTON SURFACE WATER DESIGN MANUAL 2017 City of Renton Surface Water Design Manual 12/12/2016 8-A-1 REFERENCE 8-A TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner _____________________________ Phone ___________________________________ Address __________________________________ _________________________________________ Project Engineer ___________________________ Company _________________________________ Phone ___________________________________ Project Name __________________________ CED Permit # ________________________ Location Township ________________ Range __________________ Section _________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS  Land Use (e.g., Subdivision / Short Subd.)  Building (e.g., M/F / Commercial / SFR)  Grading  Right-of-Way Use  Other _______________________  DFW HPA  COE 404  DOE Dam Safety  FEMA Floodplain  COE Wetlands  Other ________  Shoreline Management  Structural Rockery/Vault/_____  ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (check one): Date (include revision dates): Date of Final:  Full  Targeted  Simplified  Large Project  Directed __________________ __________________ __________________ Plan Type (check one): Date (include revision dates): Date of Final:  Full  Modified  Simplified __________________ __________________ __________________ Seattle Seahawks 425-203-8070 12 Seahawks Way, Renton, WA 98056 Steven D. Haluschak Magnusson Klemencic Associates 206-215-8290 VMAC Field Resurfacing 24 North 5 East 29 12 Seahawks Way, Renton, WA 98056 x Shoreline Exemptionx x November 30, 2021 x November 30, 2021 (TESC Only) VMAC Field Resurfacing Project Storm Drainage Design Figure 1 REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-2 Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: _______________________ Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: SWDM Adjustment No. ________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: ____________________________________________________________________ Special District Overlays: ______________________________________________________________ Drainage Basin: _____________________________________________________________________ Stormwater Requirements: _____________________________________________________________ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS  River/Stream ________________________  Lake ______________________________  Wetlands ____________________________  Closed Depression ____________________  Floodplain ___________________________  Other _______________________________ _______________________________  Steep Slope __________________________  Erosion Hazard _______________________  Landslide Hazard ______________________  Coal Mine Hazard ______________________  Seismic Hazard _______________________  Habitat Protection ______________________  _____________________________________ - NOT APPLICABLE (NA) NA NA NA REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-3 Part 10 SOILS Soil Type ______________________ ______________________ ______________________ ______________________ Slopes ________________________ ________________________ ________________________ ________________________ Erosion Potential _________________________ _________________________ _________________________ _________________________  High Groundwater Table (within 5 feet)  Other ________________________________  Sole Source Aquifer  Seeps/Springs  Additional Sheets Attached Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE  Core 2 – Offsite Analysis_________________  Sensitive/Critical Areas__________________  SEPA________________________________  LID Infeasibility________________________  Other________________________________  _____________________________________ LIMITATION / SITE CONSTRAINT _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________  Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply): Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: 1 / 2 / 3 dated:__________________ Flow Control (include facility summary sheet) Standard: _______________________________ or Exemption Number: ____________ On-site BMPs: _______________________________ Conveyance System Spill containment located at: _____________________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: _____________________ Contact Phone: _________________________ After Hours Phone: _________________________ Vertical drainage from field(s) to Lake Washington NA NA NA NA Only Core Requirement (CR) #5 and the Bond Worksheet from CR #7 apply NA NA Sergio Pedroza (425) 864 - 0450 (425) 864 - 0450 REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-4 Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Maintenance and Operation Responsibility (circle one): Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog or Exemption No. _______________________ Special Requirements (as applicable): Area Specific Drainage Requirements Type: SDO / MDP / BP / Shared Fac. / None Name: ________________________ Floodplain/Floodway Delineation Type (circle one): Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): _______________ Datum: Flood Protection Facilities Describe: Source Control (commercial / industrial land use) Describe land use: Describe any structural controls: Oil Control High-Use Site: Yes / No Treatment BMP: _________________________________ Maintenance Agreement: Yes / No with whom? _____________________________________ Other Drainage Structures Describe: NA NA Only Bond Worksheet NA NA NA NA NA No Special Requirements (SR) apply REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-5 Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION  Clearing Limits  Cover Measures  Perimeter Protection  Traffic Area Stabilization  Sediment Retention  Surface Water Collection  Dewatering Control  Dust Control  Flow Control  Control Pollutants  Protect Existing and Proposed BMPs/Facilities  Maintain Protective BMPs / Manage Project MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION  Stabilize exposed surfaces  Remove and restore Temporary ESC Facilities  Clean and remove all silt and debris, ensure operation of Permanent BMPs/Facilities, restore operation of BMPs/Facilities as necessary  Flag limits of sensitive areas and open space preservation areas  Other _______________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description  Detention  Infiltration  Regional Facility  Shared Facility  On-site BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________  Vegetated Flowpath  Wetpool  Filtration  Oil Control  Spill Control  On-site BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS  Drainage Easement  Covenant  Native Growth Protection Covenant  Tract  Other ____________________________  Cast in Place Vault  Retaining Wall  Rockery > 4′ High  Structural on Steep Slope  Other _______________________________ x x x x x No runoff anticipated, field vertical drainage system No runoff anticipated No runoff anticipated No runoff anticipated No dust anticipated No groundwater and/or runoff anticipated Traffic limited to barge ramp x This is the only applicable item NA NA NA Structural + Civil Engineers 1301 Fifth Avenue, Suite 3200 Seattle, Washington 98101-2699 T: 206 292 1200 F: 206 292 1201 December 1, 2021 12 Seahawks Way Renton, Washington STORMWATER POLLUTION PREVENTION AND SPILL PLAN Stor mwater Pollution Pr evention and Spill Plan Virginia Mason Athletic Center, Renton, Washington 1 1 – PROJECT OVERVIEW The Virginia Mason Athletic Center (VMAC) project in the City of Renton (City), Washington is located at 12 Seahawks Way, in between Lake Washington and Interstate 405. The proposed VMAC project is and engineered turf maintenance project, in which approximately 5,340 cubic yards of sand and organic material will be excavated from the fields via a barge in Lake Washington. The project includes the following tasks: ◼ Tilling and excavating the existing turf fields. ◼ Hauling the excavated soil to a barge in Lake Washington. ◼ Installing approximately 248,000 square feet of new natural turf sod. 2 – EROSION CONTROL SPECIALIST The Erosion and Sediment Control (ESC) supervisor will be Sergio Pedroza, as identified on the Technical Information Report (TIR) Worksheet. 3 – EXISTING SITE CONDITIONS The project is located on the existing turf fields, which receive no off-site flows. The site is flat and consists of an engineered field system with vertical drainage which does not discharge any surface flows to the surrounding area. 4 – ADJACENT AREAS The easterly boundary of the site is Seahawks Way and the Eastside Rail Corridor Multiuse Trail. The area to the north is the Seahawks headquarters and indoor practice facility, and to the south is Industrial land. Lake Washington lies to the west of the site. Stormwater runoff in the project vicinity generally flows from the east to the west towards Lake Washington, although there are no off-site flows impacting the project site. 5 – CRITICAL AREAS West of the project site is Lake Washington and a wetland adjacent to the site, both of which lie entirely outside the project limits. A portion of the site is located within the shoreline setback. 6 – SOILS The existing project soils are engineered turf field subbase, which consists of clean, imported sand with a small amount of organic accumulation. Stor mwater Pollution Pr evention and Spill Plan Virginia Mason Athletic Center, Renton, Washington 2 8 – POTENTIAL EROSION AND POLLUTION -GENERATING ACTIVITIES Erosion problems during maintenance of the VMAC turf are unlikely if the Best Management Practice (BMP) guidelines shown on the plans and outlined in this report are followed. Off-site flows that could cause erosion within the project limits are intercepted and do not enter the site. The disturbed area will be within the field footprint and containment curb. Any runoff will infiltrate vertically through the field soils and into the existing field subdrainage system. Consistent with the general permit requirements, potential pollutants other than sediment will be handled and disposed of in a manner that does not cause contamination of storm water. Non-sediment pollutants that may be present during construction activities include petroleum products including fuel, lubricants, and hydraulic fluids. These materials, and other materials used during construction with the potential to impact storm water, will be stored, managed, used, and disposed of in a manner that minimizes the potential for releases to the environment and stormwater. 8 – CONSTRUCTION BMPS ◼ Clearing Limits: Clearing limits will be delineated by the existing sidewalk and containment curb of the fields. ◼ Construction Access: Construction Access will be a barge ramp. ◼ Flow Rates: Flow control is not required for the project. ◼ Sediment Controls: Compost filter socks, sandbag barriers, and stone bag inlet protection are shown on the drawings predominantly at the perimeter of the site. The facility is designed in accordance with the City Amendments to the King County Surface Waster Design Manual. The TESC Plan Notes indicate that State of Washington (State) water quality standards are applicable to construction site runoff. ◼ Soil Stabilization: Soil stabilization is not required for the project. ◼ Slope Protection: Slope protection is not required for the project. ◼ Drain Inlet Protection: Adjacent downstream or down-slope catch basin inlets will be protected per the City of Renton standard inlet protection detail and per the following guidelines: — Storm drain inlets operable during construction shall be protected so that sediment-laden runoff does not enter the conveyance system without first being filtered or treated to remove sediment. — Approach roads shall be kept clean because site access will be via barge, not roads. — Inlets should be inspected weekly at a minimum and daily during storm events. Inlet protection devises should be cleaned or removed and replaced before six inches of sediment can accumulate. Stor mwater Pollution Pr evention and Spill Plan Virginia Mason Athletic Center, Renton, Washington 3 ◼ Pollutant Control: No sediment-laden runoff is anticipated to leave the site. Other pollutant control guidelines include: — Pollutants, including waste materials and demolition debris, that occur on site during construction shall be handled and disposed of in a manner that does not cause contamination of surface water. — Maintenance and repair of heavy equipment and vehicles involving oil changes, hydraulic system drain down, solvent and de-greasing cleaning operations, fuel tank drain down and removal, and other activities which may result in discharge or spillage of pollutants to the ground or into surface water runoff must be conducted using spill prevention measures, such as drip pans. Contaminated surfaces shall be cleaned immediately following any discharge or incident. Emergency repairs may be performed on-site using temporary plastic placed beneath, and, if raining, over the vehicle. — The use of fertilizers is not anticipated as part of this project. — The use of soil stabilization polymers, water treatment chemicals, and paints is not anticipated as part of this project. — The use of concrete construction is not anticipated as part of this project. — BMPs shall be used to prevent or treat contamination of surface water runoff by pH modifying sources. These sources may include exposed aggregate processes. ◼ Spill Response: The primary objective in responding to a spill is to quickly contain the material(s) and prevent or minimize their migration into field soils and/or storm water runoff and conveyance systems. If the release has impacted on-site storm water, the released materials on site shall be contained, preventing their release into receiving waters. If a spill of pollutants threatens stormwater at the site, the spill response procedures outlined below must be implemented in a timely manner to prevent the release of pollutants. — The ESC supervisor will be notified immediately when a spill, or the threat of a spill, is observed. The ESC supervisor will assess the situation and determine the appropriate response. — If spills represent an imminent threat of escaping ESC facilities and entering the receiving waters, facility personnel will respond immediately to contain the release and notify the superintendent after the situation has been stabilized. — Spill kits containing materials and equipment for spill response and cleanup will be maintained at the site. Each spill kit may contain: • Oil absorbent pads (one bale) • Oil absorbent booms (40 feet) • 55 gallon drums (2) • 9 mil plastic bags (10) • Personal protective equipment including gloves and goggles — The ESC supervisor, or his/her designee, will be responsible for completing the spill reporting form and for reporting the spill to the appropriate state or local agency. — Facility personnel with primary responsibility for spill response and cleanup will receive training from the ESC supervisor. This training will include identifying the location of spill kits and other spill response equipment and the use of spill response materials. Stor mwater Pollution Pr evention and Spill Plan Virginia Mason Athletic Center, Renton, Washington 4 — Spill response equipment will be inspected and maintained as necessary to replace any materials used in spill response activities. ◼ Dewatering: Dewatering is not required for the project. ◼ BMP Maintenance: Maintenance of erosion control and pollution prevention BMPs will be on a continuing basis throughout the construction process in accordance with the site improvement (temporary erosion and sediment control) plans. The applicant understands that the use of additional BMPs may be required based on soil conditions, precipitation, and construction activities. — Temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with the BMPs. — Sediment control BMPs shall be inspected weekly or after a runoff-producing storm event during the dry season and daily during the wet season. The inspection frequency for stabilized, inactive sites shall be determined by the City based on the level of soil stability and potential for adverse environmental impacts. — Temporary erosion and sediment control 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 removed or stabilized on site. Disturbed soil resulting form removal of BMPs or vegetation shall be permanently stabilized. ◼ Project Management: A copy of the approved plans and this report will be on site at all times during construction. Seasonal work limitations as determined by the City shall be adhered to. — Inspection and Monitoring: BMPs shall be inspected, maintained, and repaired as needed to assure continued performance of their intended function. — Reporting: Report spillage or discharge of pollutants within 24 hours. — Maintenance: Maintenance and repair of heavy equipment and vehicles involving oil changes, hydraulic system drain down, solvent and degreasing cleaning operations, fuel tank drain down and removal, and other activities which may result in discharge or spillage of pollutants to the ground or into surface water runoff must be conducted using spill prevention measures, such as drip pans. Contaminated surfaces shall be cleaned immediately following any discharge or incident. Emergency repairs may be performed on-site using temporary plastic placed beneath and, if raining, over the vehicle. 9 – POTENTIAL CONSTRUCTION PHASING AND SCHEDULE A potential construction sequence is: 1. Attend pre-construction conference with City of Renton representatives prior to starting any work. 2. Flag all clearing and demolition limits. 3. Install inlet protection and sediment barriers in locations as shown on the TESC plans. 4. Till and excavate existing turf fields. 5. Export excavated turf and field soils via barge. Stor mwater Pollution Pr evention and Spill Plan Virginia Mason Athletic Center, Renton, Washington 5 6. Install new natural turf sod over regraded and recompacted field soils. 7. Erosion control facilities shall remain in place until the site soils have been stabilized and the new field surface is installed. 8. Remove all sediment from drainage structures and pipes in the vicinity. 9. Contractor to remove catch basin protection and other TESC facilities only as directed by the owner at substantial completion of the project. 10. Contractor shall repair and/or restore landscape and/or site features after removal of the TESC facilities.