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TABLE E-'la GROUNDWATER SCREENING LEVELS FOR EVALUATION OF POTENTIAL VAPOR INTRUSION CONCERNS (volatile chemicals only) "Residential — ammerc a n ustria Land Use Land Use Vadoso Zone Soil Type Vadose-Zone Soil Type High LowlModerate High LowfModerate Physical Permeability Permeability Permeability Permeability CHEMICAL PARAMETER State (uglL) (uglL) (ugll-) (ug1L) TRICHLOROETHANE 11,1- V L 13E+05 52E+05 36E+05 13E+06 TRICHLOROETHANE,1 1 2- V L 3 5E+02 7 6E+02 1 2E+03 2 5E+03 TRICHLOROETHYLENE V L 5 3E+02 2 OE+03 i 8E+03 6 9E+03 RICHLOROP14ENOL 2 4,5 V S 8 3E+05 7 3E+05 i ZE+06 1 2E+06 TRICHLOROPHENOL 2,4 6- NV S VANADIUM ANV S VINYL CHLORIDE G 3 8E+00 i 7E+01 1 3E+01 5 8E+01 XYLENES L 16E+05 16E+05 16E+05 16E+05 INC S Red >25 change In comparison vu y 2003 t ano added to February 2005 IFSLs Notos 1 "Residential"screening levels generally considered adequate for other sensitive uses(e g,day-care centers,hospitals,etc) 2 High permeability soil model One meter dry sandy soil(92%sand,5%silt,3%clay)over one meter moist clayey loam(33%sand 34%silt,33%cla } 3 Low/Moderate permeability soil model One meter dry loamy sand(83%sand,I I%silt,6%clay)over one meter moist silt(7%sand 87%silt,6%cl } For inclusion in Tier 1 screening levels,all groundwater assumed to potentially migrate under a residentlaI area Screening levels for protection of Indoor air under a residential exposure scenario carred forward for use at both residential and commercialllndustrtai sites(see Table F series) Screening levels calculated using spreadhseet provided with User's Guide for the Johnson and Effinger Indoor Arr model(1991)for Subsurface Vapor Intrusion Into Buildings(USEPA 2003) Assumed vadose-zone thicknessfdepth to groundwater three meters See Appendix 1 text for model details Physical state of chemical at ambient conditions(V-volatile,NV-nonvolatile S-ld L-liquid G-gas) Chemical considered to be"volatile"if Henry's number(atm m3fmole)>0 00001 and molecular weight X200 Dibromochloromethane dibromochloropropane and pyrene considered volatile for purposes of modeling(USEPA 2004) Target cancer risk=f E-OG Target Hazard Quotient=0 2 V" Nonchlerinated VOCs(except MTBE)adjusted upwards by factor of ten to account for assumed biodegradation in vadose zone prior to emission at surface INTERIM FINAL-February 2005 SF Bay RWQCB Page 4 of 4 Table E-1a(GW to IA)