Laserfiche WebLink
Strata may grade laterally and vertically in the region and is typical San Joaquin Valley sediment <br /> depositional environments The site borehole data indicate that the uppermost shallow aquifer <br /> and underlying aquitard have some lateral continuity but are assumed to have some leakage <br /> Chemical Analysis <br /> Ten soil samples and three groundwater samples were analyzed at Kiff Analytical LLC, a <br /> certified analytical laboratory Samples were tested for the following, Total Petroleum <br /> hydrocarbons as Gasoline (TPHG), Benzene (B), Toluene (T), Ethylbenzene (E), Xylene (X), and <br /> Volatile Organic Compounds (VOC), Methyl-tert-butyl-ether (MTBE), and fuel oxygenates tert- <br /> Amyl-Methyl-Ether, Ethyl-tert-Butyl-Ether, Di-Isopropyl Ether and tert-Butyl Alcohol (TAME, <br /> ETRE, DIPE, TBA), Methanol, Ethanol, 1,2-Dichlorethane and Ethylene Dibromide using EPA <br /> Methods 3550, 351018015, 5030, 8020 and 8260 The analytical reports are attached and the data <br /> is presented in Tables 1 and 2 below <br /> Discussion <br /> So ermcal data show that TPHG and TPHD contaminants were detected TPHG was detected <br /> -� a i 70)Rg/kg and TPHD at 9,000 mg/kg at about 11 feet, assumed to correspond to the <br /> capillary fringe region Very low detections of Ethylbenzene and Xylenes were present in B-2 <br /> and B-3 soil samples MTBE and related fuel oxygenates were not detected in any soil or <br /> groundwater sample Contaminants were not detected in the underlying aquitard strata at depths <br /> of 26 and 32 feet <br /> The groundwater samples showed that contaminants were not detected in B-1 High dissolved <br /> concentrations of TPHG (34,000 ug/1) and TPHD (750,000 ug/1) were present in B-3 <br /> samples The B-3 sample also showed 1,600 ug/l Xylenes B-2 data showed 450 ug/l TPHG and <br /> 8,100 ug/1 TPHD The groundwater measurement data did not allow for gradient mapping, <br /> however the assumed groundwater flow direction is northerly toward the Delta property The <br /> dissolved plume shows the highest concentrations at the sidewalk, effectively at the Delta <br /> property line <br /> The laboratory reported that the chromatographic pattern of the water samples did not match the <br /> Diesel standard This indicates that the TPHD in the samples is highly degraded and depleted in <br /> volatile content A small dissolved plume of TPHG and TPHD has migrated from the tank pit <br /> and was present at Boring B-3 in the sidewalk near the Delta Disposal property line <br /> Page 3 of 6 <br />