Laserfiche WebLink
Technical Data Summary <br /> The Southland Corporation 9110 Thornton Road Stockton,CA z <br /> A hl 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 2BY. <br /> 4 <br /> s <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 microgramsAiter), and the highest TPHg concentration was 74 <br /> micrograms/liter(Ng/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 /> fbs/da <br /> y(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$1,226,510 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. Soil confirmation samples were collected in 1993 under <br /> SJPHS supervision, and did not contain detectable levels of TPHg and benzene. <br /> F <br /> DOW GROUNDWATER <br /> DOE]TECHNOLOGY <br /> w <br />