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HomeMy WebLinkAbout12567-CI-CLNT-ENVT Rqmts for Superfund SITE-2003-05-05 INTEROFFICE COMMUNICATION CAT. NO. 4487 CORPORATE ENVIRONMENTAL DEPARTMENT May 5, 2003 To: D. D. Bennitt Cc: R. E. Bangert II V. L. ZumBrunnen From: L. C. Robbins Subject: Requirements related to the PDS Renton Superfund Site Environmental requirements related to the PDS Renton Superfund site follow. Please note however that this year, Ecology is due to review 5 years of groundwater monitoring data to determine if the site clean-up is performing as planned. The environmental requirements for redevelopment of the property may change as a result of this review. Costs for compliance with these requirements must be charged to the redevelopment project budget. 1. Both soil and groundwater may be contaminated and thus grading, excavation or trenching of soil below the minimum 12 " structural cap must be conducted by a contractor that is trained and conducts the work in accordance with WAC 296-62-300, Hazardous Waste Operations and Emergency Response. A Health and Safety Plan will be needed. See attached Heath and Safety Requirements applicable to any work performed below the level of the structural cap. 2. Soils greater than 12" in depth must be assumed to be contaminated. If the site soil is visibly clean and can be re-used on-site it must be stockpiled in a manner that prevents dust and stormwater contact including plastic sheeting underneath, and a cover each evening and during weather conditions that may result in dust or stormwater impacts. Berms should be used to avoid excessive stormwater contact with potentially contaminated soil. Erosion, stormwater and dust control plans will be needed. If the potentially contaminated but visibly clean soil is not re-used on-site, the soil stockpiles must be sampled with a 5-point composite sample for each individual stockpile or for each 500 cubic yards within a single stockpile, whichever is more, and tested for proper disposal. Soil stockpiles should be segregated in a manner that prevents contamination of clean soil and minimizes disposal costs. CED must pre-approve the disposal site(s). Copies of all test results, shipping papers and the final disposal site must be provided to CED. Off-site disposal of more than 200 cubic yards of potentially contaminated soil in any 3 month period must be pre-approved by CED and Ecology. 3. If visibly contaminated soil, debris or groundwater is encountered, CED should be notified immediately. With approval from CED, proceed with Hot Spot Removal Action (HSRA) for visibly contaminated soil as detailed in Item 15. Removed groundwater should be stored in a portable Baker tank. Visibly contaminated debris must be stockpiled on plastic and covered each evening or if weather conditions are such that wind or stormwater could contact and mobilize any contaminated soil that is adhering to the debris. Berms should be used to prevent excessive contact of stormwater runoff with potentially contaminated debris. May 5, 2003 Page 2 4. Backfilling is allowable with either clean imported fill or visibly clean site soils. However, unless testing is performed to confirm that the visibly clean site soils meet MTCA clean-up levels, the site soil backfill must be covered with a minimum 12 " of clean imported backfill even under buildings or paved areas. Where the structural cap is disturbed it must be repaired or replaced to a minimum depth of 12 ", even under buildings or paved areas. 5. Excavations and trenches that may require future access for maintenance or repairs such as stormdrains or utility trenches must be lined with a geotextile as a marker and backfilled with clean imported fill. 6. Avoid collecting excessive stormwater in trenches and excavations with berms and other surface water diversions. 7. Contact CED if free-product or a sheen is visible in any encountered groundwater. With verbal approval from CED, collect the free-product or sheen with absorbent materials and properly dispose. 8. Potentially impacted soils and groundwater must not be stored south of the Aquifer Protection Zone. See attached Figure 2. 9. The dust control plan must include dust control measures such as water spaying for all operations that could generate dust. No visible dust is allowed. 10. A soil erosion plan is required to prevent erosion due to stormwater runoff or run-on from excavations, stockpiles, graded areas or other exposed site soils. Measures such as berms, straw bails, plastic covers and other means must be taken to control soil erosion. 11. Measures must be taken to protect site groundwater monitoring wells. CED must be notified of any well damage. The contractor shall be required to properly abandon and replace to meet or exceed original conditions, any damaged wells. 12. Site access shall be limited. No access will be allowed to the other parts of the PDS Superfund site. Any damage to the structural cap will be the responsibility of the contractor. If the existing access gate and road are damaged or removed the contractor will be asked to replace to meet existing conditions or better. 13. Site equipment that contacts potentially contaminated soil must be washed prior to leaving the site. Wash water must be collected for proper disposal. 14. Sales tax exemptions apply to remediation projects in Washington State under some circumstances. The contractor should be asked to apply for any application sales tax exemptions if remediation efforts such as disposal of contaminated soil or groundwater are required. The contractor may need a copy of the Consent Decree in applying for sales tax exemptions. PACCAR will make copies of the Consent Decree available upon request. May 5, 2003 Page 3 15. Hot Spot Removal Action (HSRA): If visibly contaminated soil is encountered a representative sample should be taken and analyzed for the Hot spot Action Levels (HSAL) provided below in accordance with the EDR Vol C.: Soil Constituent HSAL (mg/kg) Prep Method Analytical Method TPH 2,500 SW 3550 EPA 8015 Modified CPAH 100 SW 3550 EPA 8310 Lead 3,000 SW 3050 EPA 6010 Chromium 600 SW 3050 EPA 6010 Arsenic 100 SW 3050 EPA 6010 PCB 7 SW 3580 EPA 8080 If any of the HSAL are exceeded the soil must be excavated and properly disposed off-site. Excavate until visible contamination has been removed and then confirm residual (not excavated) soils are below the HSAL. Confirmational soil samples must be taken from the bottom and sidewalls of the excavation as shown in Figure 1. Hot spots will be sampled on a 10 foot grid. One four point composite sample will be taken for each 800 square foot excavated bottom. One four point composite sample will also be taken for each 40 linear feet of side wall per layer of strata. Subsamples will be collected at midpoints of the strata. If the composite samples exceed a HSAL then excavation will continue until confirmational samples are below HSAL. However, excavations will not be continued vertically below an underlying protective silt layer. Pending disposal all soils exceeding HSAL must be stored in bermed, lined and covered stockpiles such that wind or stormwater will not contact and mobilize the contaminated soil. Berms should be used to prevent excessive contact of stormwater runoff with contaminated soil stockpiles. Soil stockpiles should be segregated in a manner that prevents contamination of clean soil and minimizes disposal costs. For disposal purposes, a 5 point composite sample will be taken for every 500 cubic yards of stockpiled soil. CED must pre-approve disposal sites. Copies of the shipping papers (manifests) test results, and disposal location must be provided to CED. Pre-approval from CED and Ecology is required for off-site disposal of greater than 200 cubic yards in any three-month period. Proper storage on-site is required prior to disposal. May 5, 2003 Page 4