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Facility and PBR Units Closure Work Plan 1848 and 1856 Field Ave., Stockton, California r 4.0 CLEANUP GOALS ` In general,we consider cleanup goals to be those levels above which further cleanup is appropriate and below which no further action is required. Given the seven issues or potential issues listed above, cleanup goals ` appear necessary for petroleum hydrocarbons, pH and copper. Cleanup goals for these chemicals were previously proposed in the Facility Closure Plan (Earth Tech, 2001). Cleanup goals for each of these chemicals are presented below. hi some circumstances, Tyco is proposing modifications to the previously proposed goals, generally making the proposed goals more stringent. rr hi the Facility Closure Plan, Tyco previously proposed a cleanup goal of 100 mg/kg for TRPH. It is our opinion that 1,000 mg/kg is actually a more appropriate cleanup goal,because the petroleum hydrocarbons released from the compressor and lamination press are relatively viscous,relatively non-toxic,and relatively immobile.MSDSs for the compressor oil and lamination press oil are attached as Appendix A. However,in order to facilitate the County review and approval process,Tyco proposes to continue to use the 100 mg/kg ` cleanup goal for TRPH.If petroleum hydrocarbon levels between 100 mg/kg and 1,000 mg/kg would result in excavation that might adversely impact building stability,Tyco reserves the right to revisit this cleanup goal ` with the County. In the Facility Closure Plan,Tyco previously proposed a cleanup goal of 76,000 mg/kg for copper in soil.This level was proposed because it was the United States Environmental Protection Agency (EPA) Region IX preliminary remediation goals(PRG)for industrial settings,considered by EPA to be a conservative estimate of acceptable residual risk for an industrial land use. Since the release ofthe Facility Closure Plan,the EPA has lowered the industrial PRG for copper to 41,000 mg/kg. In comparison,the residential PRG(for residential land uses) is 3,100 mg/kg. For further comparison, Earth Tech used equations in the DTSC's Preliminary Endangerment Assessment Guidance Manual(DTSC, 1994)to calculate the copper concentration in industrial ` soil which results in a hazard quotient of 1.0 (essentially one-in-one-million risk)and found this level to be 54,000 mg/kg. Details of this hazard quotient calculation are presented in Appendix B. To be conservative, Tyco proposes a revised cleanup goal of 3,100 mg/kg,the EPA residential PRG for copper in soil. Further, Tyco proposes the same cleanup goal, 3,100 mg/kg, for copper in concrete. This is even more conservative than the soil cleanup goal, since there are fewer exposure routes to metals in concrete in an LAWOW690991GenemlTield WPIField Ave WPAugo3.2.dx 13 August 2003