Laserfiche WebLink
Ms.Lori Duncan <br /> C A M B R I A September 9,2005 <br /> cause groundwater to exceed applicable groundwater clean-up levels and that remaining <br /> constituents do not pose significant risks to human health or the environment. The background <br /> levels for all organic chemicals are assumed to be less than the standard analytical reporting limit. <br /> For the purposes of this CAP, Cambria assumes that the petroleum hydrocarbons detected in soil <br /> at the site may pose risks to groundwater quality, human health, and/or the environment. <br /> Cambria presents the COCs, background levels, the SSTLs determined by RBCA analysis <br /> (Attachment D), and maximum detected concentrations in soil below. <br /> © COC Background SSTLs Maximum <br /> Level Determined Detected <br /> (mg/kg) by RBCA Concentration <br /> Analysis (mg/kg) <br /> (mg/kg) <br /> TPHg < 1.0 NA 19,000 <br /> Benzene <0.005 0.097 400 <br /> Toluene <0.005 140 800 <br /> Ethylbenzene 50.005 100 200 <br /> Xylenes <0.005 19,000 1,000 <br /> mg/kg=Milligrams per kilogram(ppm) <br /> NA=Not applicable <br /> Cambria proposes that the SSTLs determined by the RBCA analysis for BTEX compounds be <br /> adopted as the soil clean-up goals. As discussed above,based on the complex mixture and varied <br /> nature of TPHg, there is no calculated SSTL for it. Guidance from the San Francisco Bay <br /> RWQCB (Screening For Environmental Concerns at Sites With Contaminated Soil and <br /> Groundwater [Interim Final — February 20051) provides a soil screening level of 100 ppm to <br /> protect drinking water. Therefore,Cambria proposes a soil clean-up goal of 100 ppm for TPHg. <br /> Although significant reductions of COCs in soil concentrations can be attained by various <br /> remedial alternatives, attainment of the approved soil clean-up levels may prove to be technically <br /> or economically infeasible. Thus, soil clean-up may be limited to that which is technically or <br /> economically feasible. <br /> 11 <br />