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06/92/1993 16: 17 FROM ROGER FOOTT A55 WSRG TQ 12394640135 P.03 <br /> Mr.John Pollock <br /> June 2, 1993 <br /> Page 2 <br /> the gasoline range,benzene, toluene.etbylbeazerle,and ethylene dibromide were not <br /> detected in the sail sample at or above the detection limits. <br /> PROPOSED INVESTIGATION <br /> Additional investigation is required to evaluate the potential tb reat of soluble <br /> lead leaching to the groundwater surface. The groundwater surface at the site is <br /> expected to be located at depths ranging between 120 ft and 150 ft beneath the <br /> ground surface. <br /> Our proposed scope of work includes drilling, lagging„and sampling one soil <br /> boring to a depth of 15 ft,laboratory analysis of one sail sample for soluble lead,and <br /> appropriate reporting. <br /> SO Borin <br /> The baring will be drilled by a licensed well-driller using a SIMCO portable <br /> drilling rig equipped with 4-in hollow-stent augers. Drilling equipment,including <br /> augers add sarnplers,will be Steain-cleaned prior to use in the boring. Sail samples <br /> will be collected at 5-ft intervals and/or at lithologic contacts is the boring using a <br /> California-modified split-spoon sampler fitted with clean stainless steel sleeves. The <br /> sampler will be cleaned in an Alconox solution and rinsed with deionized water <br /> between.samples. A phatoionizing organic vapor meter(OVM)will he used during <br /> sampling to detect potential hydrocarbon concentrations in the soul samples. <br /> Drilling operations will be supervised by a qualified environmental geologist <br /> and soils will be logged using the Unified Soil Classification System. Drill cuttings <br /> will be placed on plastic sheeting,covered with plastic,and left onsite pending the <br /> results of laboratory analyses. The soil boring will be abandoned by.backrAling with a <br /> slurry of neat cement with less than 5%bentonite powder. <br /> At least one sample sleeve from,each sample interval will be trimmed of <br /> excess soil,sealed with aluminum foil,plastic caps,and airtight tape. The sample will <br /> be labelled,and placed into iced storage. A soil sample selected from the baring will <br /> be analyzed for lead using a waste extraction test(WET)and EPA Method 7421. <br /> These methods are recommended by the California Environmental Protection <br /> Agency,and will be performed by a Cal EPA-certified environmental laboratory. <br /> FMTT <br /> �55CrCrA tf,5 <br />