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Mr. Jeffrey Wong
<br /> March 27, 2001
<br /> Page 2
<br /> Soil samples were collected into stainless steel sample sleeves with a push-driven soil
<br /> sampler at 65, 70 and 74 feet bgs. The samples were sealed with Teflon° film and plastic
<br /> end caps, labeled, and transported in an iced cooler with chain-of-custody documentation to
<br /> Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste testing laboratory
<br /> (Certification 42236). Kiff analyzed all three soil samples for Total Petroleum Hydrocarbons
<br /> (TPH)-as-gasoline, benzene, toluene, ethylbenzene, xylenes (BTEX), methyl tertiary butyl
<br /> ether(MTBE), di-isopropyl ether(DIPS), ethyl tertiary butyl ether(ETBE), tertiary amyl
<br /> methyl ether (TAME), tertiary butanol (TBA), 1,2-dichloroethane (1,2-DCA) and 1,2-
<br /> dibromoethane (EDB) by EPA Method 8260B.
<br /> All three soil samples contained relatively low concentrations of at least one compound
<br /> analyzed. The sample collected at 65 feet contained 10 milligrams per kilogram (mg/kg) of
<br /> TPH-as-gasoline, 0.15 mg/kg of benzene, 0.14 mg/kg of toluene, 0.26 mg/kg of
<br /> ethylbenzene, and 0.73 mg/kg of xylenes. The sample collected at 70 feet only contained
<br /> 0.0071 mg/kg of toluene, and the sample collected from 74 feet only contained 0.02 mg/kg of
<br /> toluene, 0.0068 mg/kg of ethylbenzene and 0.05 mg/kg of xylenes. The five oxygenate
<br /> compounds, 1,2-DCA and EDB were not detected in any of the three soil sample analyses.
<br /> The certified laboratory report is enclosed.
<br /> Based on the CPT and pore pressure dissipation data, groundwater-bearing sand and gravel
<br /> sequences were identified beneath the groundwater table at approximately 60 and 105 feet
<br /> bgs. Gregg discretely sampled the groundwater interval at 60 feet bgs using a SimulProbe.
<br /> The SimulProbe is deployed under back pressurization to prevent sample interference from
<br /> overlying groundwater intervals. The sample was collected into laboratory supplied
<br /> containers, which were labeled, packaged in an iced cooler, and transported with chain-of-
<br /> custody documentation to Kiff for analysis. Kiff analyzed the groundwater sample for TPH-
<br /> as-gasoline, BTEX, MTBE, DIPS, ETBE, TAME, TBA, 1,2-DCA and EDB by EPA Method
<br /> 8260B. As directed by the PHSIEHD inspector, the groundwater interval at 105 feet was not
<br /> sampled.
<br /> The groundwater sample collected at 60 feet bgs contained 5,700 micrograms per liter (pg/l)
<br /> of TPH-as-gasoline, 76 µg11 of benzene, 61 µg/1 of toluene, 53 pgll of ethylbenzene, 280 µg11
<br /> of xylenes, and I 1 µg/l of 1,2-DCA. The five oxygenate compounds and EDB were not
<br /> detected in the groundwater sample. The certified laboratory report is enclosed.
<br /> Following sampling, Gregg sealed the boreholes with cement grout, placed by the tremie
<br /> method.
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