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DeBoer Family Trust 201 West 5th Street, Ripon, California June 20, 1995` : k Soil/Groundwater Workplan Page. S blank is listed on the Chain of Custody, but will be analyzed only if all samples contain' the same contaminants. .�a All sampling equipment including the pump, bailer, and cables, used by sampling; personnel, is disassembled, if appropriate, and steam-cleaned prior to commencement' .,, of sampling. These procedures are also followed between each well, sampling point, and at the end of the sampling day. De-ionized or organic-free water(also provided by the laboratory) is then introduced into the pump or bailer as a final stage of cleaning. This water is then pumped or gently poured into sample vials to be used as pump or, bailer blanks. These blanks are tested only if their corresponding samples were found to contain contaminants. Immediately prior to sampling, water levels and well depth measurements are recorded, in all wells at the site. Each well is evacuated using either a stainless steel bladder pump, which does not introduce air into the water column, or a Teflon bailer. The pH, temperature, and electrical conductivity of the water is monitored with instruments calibrated to known standards as the wells are evacuated. These parameters are noted on field logs. At least 5 well volumes are evacuated from each well, or more, as .. necessary, until the above parameters have stabilized. The wells, or other sampling points, are sampled in order of the least to the most contaminated, as best known or; estimated. The samples are pumped from a stainless steel bladder pump or carefully poured from a Teflon bailer into clean glass vials with Teflon-lined screw caps and half gallon plastic containers provided by the laboratory. Care is taken to ensure that no air, space exists in the vials by inverting to check for bubbles and re-sampling if necessary. r The samples will be analyzed or extracted within 14 days according to their EPA methods. Water samples collected for analysis will be analyzed by EPA method 6021 for BTX&E compounds and method 3 510 for diesel range hydrocarbons. The; minimum detection limits used for each analyte will be 0.5 gg/kg for BTX&E and 0.5 mg/kg for diesel. Analyses will be conducted by California Laboratory Services, Inc., a State certified laboratory in Rancho Cordova, California. 4.0 Geology The borings penetrated units of silt and sand. The upper unit, to 7 feet, is a micaceous sandy silt (ML) in MW-1 & 2, but grades to a micaceous silty sand (SM) in MW-3. The underlying unit, to the total boring depth of 40 feet, is a poorly graded micaceous- FE sand (SP) in MW-2 & 3, but grades to a well-sorted sand (SW) in MW-1 from 6 to 18 feet. Within this sand unit is a two foot silty sand (SM) at 12 and 14 feet in MW-2 & 3, respectively. There is also a silt(MH)unit of two and one-half feet in MW-2 and two feet