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Drilling of boreholes will be accomplished using a mobile drilling rig equipped with four <br /> inch diameter hollow stem augers. The boreholes will be extended to groundwater at an <br /> estimated maximum depth of sixty (60) feet. The San Joaquin County Flood Control <br /> District (Mr. Bryan Jones)reports that the depth to ground water in the vicinity of the <br /> subject property is 60 feet and the ground water flow direction is from east to west <br /> (Kleinfelder Preacquisition Site Assessment- Southeast intersection of March and West <br /> Lanes, Job No. 24-2115-10). Drilling will be terminated if ground water is encountered at <br /> a lesser depth <br /> During drilling, a geologist from pH7 will direct the field operations and log the soil <br /> samples as they are obtained using the Unified Soil Classification System. Soil samples <br /> will be collected at a maximum of five foot intervals or and at significant changes in <br /> lithology using a modified California sampler with brass sample tubes. The ends of the <br /> brass tube will be covered with aluminum foil, then plastic end caps, and finally wrapped <br /> with a non-petroleum containing tape. Samples will be screened in the field using a <br /> portable organic vapor analyzer(VOA)to check for the presence of fuel compounds to <br /> assist in sample selection for laboratory analysis. Negative results with the VOA will <br /> exclude a sample from laboratory analysis. Selected soil samples will then be immediately <br /> double plastic bagged to prevent possible dilution, and placed on ice or dry ice for transport <br /> to a DHS certified laboratory (Clayton Environmental in Pleasanton). The remaining <br /> samples will be immediately refrigerated for possible laboratory analysis within the <br /> following 5 days. Samples will be analyzed for Total Petroleum Hydrocarbons as <br /> Gasoline (TPHg) utilizing EPA Method 5020, BTEX utilizing EPA Method 8015. Formal <br /> chain-of-custody records shall be maintained and submitted to the San Joaquin County <br /> Public Health for each sample analyzed <br /> Water samples will be collected using a clean Teflon bailer equipped with a flapper valve <br /> and cotton cord. The bailer will be decontaminated before sampling by washing in a <br /> trisodium phosphate solution followed by a distilled water rinse. New cotton cord will be <br /> used in each borehole. Samples will be carefully decanted into 40 ml volatile organic <br /> analysis container(VOA) sample bottles provided by the laboratory,placed in a shipping <br /> cooler with ice, and transported to Clayton Environmental in Pleasanton, CA. Chain of <br /> custody procedures will be observed. Laboratory analysis on the samples will be EPA <br /> methods 5030 and 8015 for TPH as gasoline and BTEX. <br /> A composite sample of surficial soils will be collected and submitted to Clayton <br /> Environmental for analysis by EPA Method 8080. <br /> SCHEDULE <br /> A drill rig from Bay Area Exploration in Fairfield has been scheduled for October 18, <br /> 1990. This work plan and the Application for Permit have been hand carried and submitted <br /> to San Joaquin Public Health Services on this date. We understand that it takes 3 to 5 days <br /> for permit issuance (Eleanor Ratliff, San Joaquin County Public Health Services). If <br /> permitting is delayed, the drilling date will have to be rescheduled. <br /> The Level I Environmental Assessment will be completed on or before October 25, 1990. <br /> Any negative findings will be verbally reported as they are encountered <br /> -2- <br /> 18211 Bollinger Canyon Road San Ramon CA 94583 415-831-1957 Telecopy 415-838-2151 i H7 <br /> R0 NDA <br />