Laserfiche WebLink
1992 Third Quarter Groundwater Monitoring Report <br /> ort ��--- <br /> Western Stone Products, Tracy, California <br /> lop August 28, 1992 <br /> r, Page 2 <br /> Joaquin County Public Health Services was present to witness the sampling. Disposable bailers <br /> were used to collect the samples. Purge logs are included in Attachment 1. <br /> The samples were collected, preserved and transported under chain-of-custody and in accordance <br /> with EPA and DHS protocol. The samples were analyzed by RESNA Environmental <br /> Laboratories (DHS cert. #1211) for TPHD and BTEX utilizing EPA methods 3510/8015 and <br /> 503018020, respectively. Table 2 summarizes analytical results. Attachment 2 contains <br /> laboratory data sheets, and chain-of-custody documentation. <br /> The water sample collected from well MW3 contained toluene at 0.55 parts per billion (ppb) and <br /> MW4 contained 0.60 ppb toluene, 1.2 ppb Ethylbenzene, 0.57 ppb total xylenes. No other <br /> petroleum analytes were detected. <br /> SOIL BORINGS <br /> On July 27, 1992 RESNA personnel supervised the drilling and sampling of two soil borings. <br /> The borings were installed within the former tank pit (SB1) and east of the former tank pit (SB2) <br /> by Spectrum Exploration. The borings were drilled to 10 feet below grade (drive sampling to <br /> -fes <br /> 11.5 feet), with samples collected at 5.5 feet, 8.0 feet and 11 feet below grade from boring SB1, <br /> and at 5.5 feet, 8.5 feet and 11 feet from boring SB2. Clayey silt was encountered from surface <br /> grade to total depth in both borings. Samples were collected in brass sleeves with a modified <br /> California split spoon sampler, sealed with teflon tape, and a plastic cap, placed in a plastic bag <br /> on crushed and blue ice in a cooler. Samples were transported to RESNA Environmental <br /> Laboratories, (DHS cert.# 1211) for analysis. Subsequent to completion, the borings were <br /> abandoned by backfilling to the surface with a 10 sack sand/cement grout over bentonite. Boring <br /> logs are included in Attachment 3. <br /> Soil samples collected from SBI and SB2 were analyzed for BTEX and TPHD by EPA methods <br /> 5030/8020 and 3550/8015 respectively. TPHD was detected in soil samples collected from the <br /> former tank pit (SB1). TPHD was detected in samples SBI-5.5' (740 ppm), SBI-8' (53 ppm), <br /> and SB1-11' (2.2 ppm). Low concentrations of aromatics were also detected in these samples. <br /> No petroleum hydrocarbon analytes were detected in the samples collected from boring SB2. <br /> Soil sample results are summarized in Table 3. Laboratory data sheets and chain-of-custody <br /> documentation are included in Attachment 2. <br /> Depicted on Figures 3 and 4 is the estimated extent of residual soil contamination in the former <br /> tank pit area. The estimated extent is based upon concentration levels detected in the soils <br /> QR081292.DRF <br /> i <br />