Laserfiche WebLink
4 <br /> i <br /> } <br /> Subsequent to purging, groundwater was sampled and transfe"'rred to appropriate sample <br /> i containers, using clean, disposable bailers with bottom emptying devices to reduce volatilization. <br /> Sample containers were then labeled with sample identification, placed on ice, and shipped under <br /> i ,. <br />' [[ chain-of-custody to State-certified AEN laboratory for chemical analysis. The water sample was <br />! L. analyzed for TPHg, BTEX, oxygenate fuel additives, and total�lead. ' <br /> + At the request of PHS/EHD, the on site domestic water supply well was sampled on November <br /> 24 1997. <br /> The groundwater sample was collected using a 1/2-inch bailer. The bailer encountered � <br /> an obstruction at approximately 30 feet bgs and the groundwater sample was collected from this <br /> depth. The groundwater sample was labeled with sample identification, placed on ice, and <br /> _ shipped under chain-of-custody to State-certified AEN laboratory; for chemical analysis. The <br /> water sample was analyzed for TPHg, BTEX, oxygenate fuel additives, and total lead. <br /> I <br /> Groundwater analytical results are summarized in Table 2, and' laboratory data sheets are <br /> presented in Appendix D. <br /> 3.0 SUBSURFACE CONDMONS <br /> Soils encountered beneath the site consist primarily of silts and sands to a depth of approximately <br /> 35 feet below grade, the maximum depth explored. An apparent lean clay layer was noted at a <br /> depth of approximately 25 feet to 29 feet below grade in borings SB 1, SB3, and SB4. <br /> Lr <br /> Groundwater beneath the site was first encountered at approximately 19 feet below grade. After <br /> well completion, the piezometric surface stabilized to 17.83 feet below grade. Based on the San <br /> Joaquin County Flood Control and Water District, Spring_1995 report, groundwater flows to the <br /> north-northeast. <br /> 4.0 RESULTS <br /> 4_1 Soil Contamination <br /> Results of laboratory analyses performed on selected soil samples indicate that total lead, detected <br /> ii oi <br /> L in soil samples SB2-25, SB3-5, SB4-15, SB4-25, SB5-15; and MW1-25, is present beneath the <br /> site at concentrations ranging from 3 to 7 milligrams per kilogram (mg/kg). The analytical results <br /> for total lead were consistent with the typical U.S. Mean andtypical Bay Area concentrations in <br /> soil as presented in Summary of Typical Metals Concentrations in Soils and Surficial Materials, <br /> from U.S.G.S Professional Paper 1270 for the Conterminous'�United States. Total lead was not <br /> L <br /> w:\90954\90954.03\reports\psi-doc 5 <br /> -t � SMTH <br />