Laserfiche WebLink
`J I ne owniana for oration 9110 Thornton Road Stockton GA A nl 4 1995 <br /> January 1993 all 11 confirmation soil samples collected from 9 borings under the supervision of the <br /> SJPHS,did not contain detectable concentrations of benzene and TPHg (Figure 5,Table 2B) <br /> January 13, 1994 soil vapor extraction test to determine if hydrocarbons are present in the subsurface <br /> soil,to verify past radius of capture of vapor extraction, and to estimate potential hydrocarbon mass <br /> extraction rates <br /> The laboratory analytical report(attached) indicates in air samples,the only BTEX component <br /> detected was xylenes (less than 2 micrograms/liter), and the highest TPHg concentration was 74 <br /> micrograms/liter(pg/l)(Table 3) <br /> Results of vacuum pressure response indicate that the lateral reach of the previous vapor extraction <br /> system covered the site adequately A very conservative estimate of TPHg removable by SVE is 0 5 <br /> lbs/day(using the highest measured TPHg concentration), likely to drop significantly over time <br /> COSTS TO DATE <br /> As of February 1995, The Southland Corporation has spent$1,226,610 on environmental costs for this <br /> site <br /> RATIONALE FOR SITE CLOSURE <br /> Results of site remediation activities, for both soil and groundwater, have documented the decrease of <br /> petroleum hydrocarbons in the subsurface conditions beneath the site The presence of <br /> separate-phase hydrocarbons in soil or groundwater is no longer detected The detection of low levels <br /> of BTEX and TPH-G concentrations in groundwater samples has been reported occasionally since <br /> 1990 Results of sampling indicate levels of hydrocarbon constituents have been at or below California <br /> action levels for drinking water since 1989 Sod confirmation samples were collected in 1993 under <br /> SJPHS supervision,and did not contain detectable levels of TPHg and benzene <br />