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TABLE E-2 'SHALLOW SOIL GAS SCREENING LEVELS FOR EVALUATION OF POTENTIAL VAPOR INTRUSION CONCERNS (volatile chemicals only) FResidential Exposure Commercial/lndustrial Land Use Lowest Carcinogenic Noncarcinogenic Lowast Carcinogenic Noncarcinogenic Physical Residential Effects Effects C/I Effects Effects CHEMICAL PARAMETER State (ug/m) to 1m)) (ug/m') u /m' (uglm) u !m') (CHLOROETHANE 1 1 2- V L 1 5E+02 1 5E+02 2 8E+03 5 0E+02 5 0E+02 8 2E+03 TRICHLOROETHYLENE V L 1 2E+03 1 2E+03 1 2E+05 4 1 E+03 4 1E+03 3 5E+05 TRICHLOROPHENOL 2,4 5- V 5 7 3E+04 7 3E+04 2 0E+05 2 0E+05 TRICHLOROPHENOL 2 4.6- NV S VANADIUM NV S INYLCHLORIDE V G 32E+01 32E+01 21E+04 11E+02 11E+02 58E+04 LENES V L 15E+05 15E+05 41E+05 41E+05 INC NV S Red change in comparison to u y_T6UTr:SL EthunciT—added to February 2005 ESLs Notes 1 Shallow soil gas defined as soil gas sample data collected within 1 5 meters(five feet)from a budding foundation or the ground surface Assumes very permeable(e g sandy)fill h material is present below building foundation or could be present below future buildings following redevelopment Evaluation of deeper soil gas data(e g,>1 5m bgs)should be canted out on a site-specific basis "Residential"screening levels generally considered adequate for other sensitive uses(e g day care centers,hospitals etc) Sod gas screening revels intended to be prolective of indoor air quality,calculated for volatile chemicals only Physical state of chemical at ambient conditions(V-volatile NV-nonvolatile S solid L-liquid G-gas) Chemical considered to be"volatile"if Henry's number(atm m3/mole)>0 00001 and molecular weight<200(see Table E-1) Dibromochlaromethane dibromochloropropane and pyrene considered volatile for purposes of modeling(USEPA 2004) Target cancer risk c 1 E-06 Target Hazard Quotient=0 2 for all chemicals except TPH(HQ of 0 5 used,see Sections 13 and 3 4 of text) Residential soil gas indoor air attenuation factor=0 001(111000) Commercialfindustnal soil gas indoor air attenuation factor=0 0005(112000) Sod gas screening level for ethanol based on potential indoor air nuisance concerns(refer to Section 5 3 3 and Table H series Soil gas screening levels do not address mass-balance Issues May be overly conservative for stles with low permeability shallow ods or limited soil impacts and no groundwater source of VOCs indoor air sampling and/or passive vapor mitigation measures may be prudent for sites where concentrations of chemicals In soil gas approach but do not exceed screening levels f INTERIM FINAL-February 2005 SF Say RVVQCB Page 4 of 4 Table E-2 (Soil Gas to IA)