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<br /> Phase 11 Environmental Site Assessment
<br /> Mountain House Neighborhood G
<br /> July 9,2002
<br /> Page iii
<br /> mevinphos, tetrachlorvinphos, and tokuthion were detected below the laboratory reporting limits and the
<br /> reported values are estimated concentrations. All constituents were detected below the United States
<br /> Environmental Protection Agency Region 9 Preliminary Remediation Goal values. PRGs are not
<br /> established for the organochlorine pesticides endosulfan I, endosulfan II, and endrin aldehyde or for the
<br /> organophosphorus pesticides azinphos-methyl, bolstar, coumaphos, ethoprop, famphur, fensulfothion,
<br /> fenthion, mevinphos, 0,0,0-triethylphosphorothioate, thionazin,tokuthion, and trichloronate.
<br /> Gamma-BHC, DDD, DDE, DDT,endosulfan I, endosulfan II, endrin, endrin aldehyde, heptachlor, kepone,
<br /> MCPP, azinphos-methyl, bolstar, chlorpyrifos, coumaphos, demeton, diazinon, dimethoate, disulfoton,
<br /> ethoprop, ethyl parathion, famphur, fensulfothion, fenthion, merphos, methyl parathion, mevinphos,
<br /> 0,0,0-triethylphosphorothioate, tetrachlorvinphos, thionazin, tokuthion, and thrichloronate were identified
<br /> as chemicals of potential concern (COPC) based on their varied presence in several on-site composite and
<br /> discrete samples and underwent human health risk assessment(HHRA).
<br /> For each COPC with published toxicity reference values, lifetime cancer risk (risk) and/or hazard quotient
<br /> (hazard) were calculated for soil and air using screening equations found in the Preliminary Endangerment
<br /> Assessment Guidance document published by DTSC. Lifetime cancer risk and the hazard quotients for soil
<br /> and air exposure media associated with each COPC were summed for all constituents to obtain the total
<br /> lifetime cancer risk and total hazard index which would be posed by the COPC identified at the site. The
<br /> total calculated cancer risk is 4.57E-07 and total hazard is less than unity(1.00E-01).
<br /> This assessment has revealed no evidence of recognized endangerment in connection with the property that
<br /> may result in a lifetime increased cancer risk greater than one-in-a-million or in non-cancer hazard greater
<br /> than unity. Based on the laboratory analytical results of soil samples collected as part of this Phase II
<br /> Environmental Site Assessment, Condor recommends no further action.
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<br /> +i I CONDOR
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