Laserfiche WebLink
RE" NaElVED <br /> Super Center Mart - 4- 17 March 2016 <br /> 701 East Charter Way 1 a n <br /> Stockton, San Joaquin County <br /> HEAI_T,. . -c-ARTMENT <br /> 6. The Site meets the State Water Board's LTCP's Direct Contact and Outdoor Air Exposure <br /> media specific criteria. The Site is an active retail gasoline station. Soil analytical data is <br /> presented in Table 3. Maximum soil sample concentrations are below the commercial soil <br /> screening values established in the State Water Board's LTCP. Maximum soil <br /> concentrations are detailed in the table below. <br /> Chemical Residential Commercial/Industrial Utility Site Maximums <br /> Worker <br /> 0to5ftbgs 5to10ftbgs 0to5ftbgs 5to10ftbgs 0to10ftbgs 0to5ftbgs 5to10ftbgs <br /> (mg/kg) (mg/kg) m /k (mg/kg) (mg/kg) (mg/kg) (mg/kg) <br /> Benzene 1.9 2.8 8.2 12 14 <0.6 <0.005 <br /> Eth (benzene 21 32 89 134 314 40 <0.005 <br /> Naphthalene 1 9.7 9.7 1 45 45 11 219 --- --- <br /> PAH 0.063 NA 1 0.68 NA 1 4.5 --- <br /> 1-Sampling <br /> --1-Sampling and analysis for PAH is only necessary where soil as affected by either waste oil or Bunker C fuel. <br /> NA=not applicable <br /> Based on the maximum concentrations detected in soil samples, the Site meets the State <br /> Water Board's LTCP criteria for direct contact and outdoor air exposure for commercial <br /> workers. The property is an active service station, and future land use is not anticipated to <br /> change; use of commercial screening levels is appropriate. Soil samples were not analyzed <br /> for naphthalene. Since none of the soil samples exceed the LTCP screening levels for <br /> benzene and ethylbenzene, risk to human health from naphthalene is unlikely. <br /> The shallow soil sample that contained ethylbenzene above the residential screening level <br /> was collected in 1998, and before implementation of DPE at the Site. At this time, the <br /> residual shallow ethylbenzene concentrations are most likely significantly lower than the <br /> historically detected maximum of 40 mg/kg, due to active remediation (DPE) and natural <br /> degradation. <br /> 7. The Site meets the State Water Board's LTCP's Petroleum Vapor Intrusion to Indoor Air <br /> media specific criteria. The Site is an active service station and therefore is exempt from <br /> this media specific criterion, unless site specific conditions indicate there may be an <br /> unacceptable risk. The benzene impacts at this site are confined to the station property and <br /> City of Stockton Right-of-Way, and in the vicinity of the dispenser islands. Based on <br /> available data, site specific conditions do not indicate an unacceptable risk due to vapor <br /> intrusion to indoor air. <br /> Soil gas samples were collected from four locations, SV-1 through SV-4, at the site in <br /> August 2008. Soil gas results are compared to LTCP vapor intrusion screening criteria for <br /> direct measurement of soil gas in the table below: <br /> Scenario 02>4% Depth of Soil Benzene (ug/m ) Ethylbenzene (ug/m ) Naphthalene (ug/m ) <br /> Gas Sample <br /> feet Residential Commercial Residential Commercial Residential Commercial <br /> 4a No 5 <85 <280 <1,100 <3,600 <93 <310 <br /> SITE Unknown 5 <25 <25 <25 <25 Not Not <br /> Analyzed Analyzed <br />