Laserfiche WebLink
w I 91 11 <br /> Previous Investigations Two 5,000-gallon and two 8,000-gallon steel USTs and associated piping <br /> were removed from the site in December 1988 and January 1989 Samples T-1 through T-8 were <br /> collected at a depth of approximately 15 feet below grade (fbg) beneath the former tanks <br /> Concentrations of Total Petroleum Hydrocarbons calculated as Gasoline (TPH-G) ranged from not <br /> detected (ND) to 4,880 parts per million (ppm) In January 1989, samples were collected from <br /> beneath the product lines and dispenser islands during product line excavation Sample T-3, collected <br /> beneath the western dispenser island contained TPH-G at a concentration of 1,510 ppm <br /> In August 1989 a site investigation was performed to evaluate the extent of petroleum hydrocarbons <br /> identified during UST and product line removals Wells MW-1 thorough MW-3 were installed in the <br /> vicinity of the former USTs TPH-G, benzene, toluene, ethylbenzene, and xylenes (BTEX) were ND <br /> for soil samples collected from 56 5 fbg in these well borings Soil boring SB-1 was drilled near the <br /> western fuel dispenser island sampling location T-3 Samples from 11 5 fbg and 41 5 fbg from this <br /> boring were ND for TPH-G and BTEX Soil boring SB-2 was drilled near the southern dispenser <br /> island, in the vicinity of sampling location T-I Samples from 115 fbg and 41 5 fbg from this boring <br /> were ND for TPH-G and BTEX Soil boring SB-3 was drilled through the former UST backfill <br /> location, in the vicinity of sample locations T-5 and T-7 Samples from 26 5 fbg were ND for <br /> TPH-G and BTEX <br /> Quarterly ground water monitoring and sampling has been performed at this site since October 1990 <br /> Ground water samples from MW-1 through MW-3 have been ND for TPH-G and benzene since May <br /> 1990 <br /> INVESTIGATION RESULTS <br /> Personnel Present Geologist Tom Magney directed the field sampling, working under the <br /> supervision of California Professional Engineer Diane Lundquist <br /> Permit A boring permit was obtained from the SJCPHS A copy of the <br /> permit is presented in Appendix A <br /> Drilling Company• Gregg Drilling of Martinez, California (C57 License # 485165) <br /> Drilling Date December 16, 1997 <br /> Drilling Methods 2 inch hydraulic percussion hammer probe (Geoprobe } <br /> Sampling Methods. Soil lithology was logged using the Unified Soil Classification System <br /> and the Munsell Color chart Encountered lithology is described on <br /> the exploratory boring logs presented in Appendix B The soil <br /> 240-0832 2 <br />