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Ms Lon Duncan <br /> May 24, 2002 <br /> Page 3 of 5 <br /> Drilling and well installation will be conducted under the supervision of an experienced geologist Soil <br /> samples will be collected at five-foot intervals using a split spoon style core samp 1 er lined with <br /> brass sleeves Soil samples will he collected for field screening, logging and identification in <br /> accordance with ASTM Designation D2488-90, which is equivalent to the Unified Soil Classification <br /> System The portion of the sample to be analyzed will be immediately be capped, segregated and <br /> preserved by placing in an ice chest refrigerated to a temperature of approximately 4°C for <br /> submittal under chain of custody protocol to a California-certified hazardous waste testing laboratory <br /> Selection of soil samples for laboratory analysis will be based on field evidence of petroleum <br /> hydrocarbon contamination such as discoloration, odors, and photo ionization detector (PID) <br /> readings, as well as hthologic changes If no evidence of contamination is noted in the field, <br /> samples from the capillary fringe and bottom of the boring will be submitted for analysis All <br /> sampling and drilling equipment will be washed thoroughly with laboratory-grade detergent and <br /> water between uses to minimize the potential for cross contamination Drill cuttings and <br /> wastewater generated during drilling activities will be contained and labeled pursuant to 49 CFR <br /> part 172 and 40 CFR part 262, pending laboratory results and the determination of disposal options <br /> Selected soil samples will be analyzed for the presence of VOCs and oxygenated gasoline <br /> additives using EPA Method 8260B, benzene, toluene, ethylbenzene, xylenes (BTEX) by EPA <br /> Method 8020, total petroleum hydrocarbons as gasoline (TPHg) and diesel (TPHd) by EPA <br /> Method 8015M, and total recoverable petroleum hydrocarbons (TRPH) using EPA method 418 1 <br /> or equivalent <br /> Surveying, Well Development, and Groundwater Sampling <br /> The elevations of the well casing collars will be surveyed to an accuracy of 0 01 feet A minimum of <br /> 24 hrs after completion, an experienced field technician will measure static depth to water and then <br /> develop the new wells by pumping and surging until turbidity is minimized A groundwater sample will <br /> be collected from each well after pH, temperature, and electrical conductivity have stabilized and the <br /> wells have recharged to minimum of 80% of static levels After collection, the samples will <br /> immediately be capped, labeled, segregated and placed in an ice chest refrigerated to a temperature <br /> of approximately 4°C for submittal under chain of custody protocol to a Cahfonua-certified hazardous <br /> waste testing laboratory Samples will be analyzed for the presence of TRPH, TPHd, TPHg, BTEX, <br /> VOCs, and oxygenated gasoline additives by the appropriate methods <br /> All sampling equipment will be washed thoroughly with laboratory-grade detergent and water <br /> between uses to minimize the potential for cross contamination Wastewater generated during <br /> well development activities will be contained and labeled pursuant to 49 CFR part 172 and 40 CFR <br /> part 262, pending laboratory results and the development of disposal options <br /> Vertical Definition of the VOC Contaminant Plume <br /> Since the former UST was located inside the building, a limited access drilling rig would be required to <br /> investigate the vertical extent of VOC groundwater contamination in the source area Such limited <br /> GIData1GRoUNDzE1GABBAi2Dlworkplansl3_add_MW_WORKPLAN doc <br />