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CeofaBicafTmgnics Inc. Page 2 City of Escalon Soil&Groundwater Report Project No. 750.2 March 15, 1999 p On February 23, 1999 three boreholes were drilled on site (HP-2, HP-3 & HP-6). The , boreholes were extended to the capillary fringe. A hydropunch type sampling tool was then advanced into the ground water to obtain a ground water sample. The depth to groundwater in this area was approximately 60-61 feet below grade. After the groundwater samples were collected, the boreholes were closed by pumping a neat cement grout, containing <4% bentonite to the surface by pumping the grout through the augers as they were removed from the borehole. Soil cuttings were added to the existing stockpile. Decontamination rinse water was !� containerized in DOT approved 55 gallon, steel drums and placed along side the building. 1.2 Sail Sampling Procedure During drilling, soil samples were collected for geological and analytical evaluation at five- foot intervals. Boring logs providing sediment description using the USCS and field observations were maintained by Ray Kablanow, a California Registered Geologist and �-+ Certified Hydrogeologist and Michael Niemi, geologist for GTI, working under the supervision of Ray Kablanow. Boring logs are attached in Appendix B. Soil samples were collected in 6.0-inch brass liners using a 2.0 inch modified California split spoon sampler. All soil samples were sealed with Teflon sheets, capped, labeled and placed ' -� in a cooler at 4° Celsius for transport to the laboratory following Chain of Custody protocol. Because every soil sample collected was not to be submitted for laboratory analysis, a screening process was used to gather additional information through field observation. The following was noted: sediment type, especially grain size and clay content 0 moisture content • visible evidence of contamination, i.e., color change due to reduction of iron or discoloration from hydrocarbons and other pollutants readings above background on a organic vapor meter(OVM) The OVM is a portable photo ionization detector that uses a 10.0 eV lamp to detect compounds with ionization potential below 10.0 eV (hydrocarbon range). 1.3 Groundwater Sampling i I Once the capillary fringe soil sample was collected, a hydropunch type groundwater sampling tool was advanced approximately four feet into the saturated zone. The tool was retracted approximately two feet to expose the screen. A narrow Teflon or stainless steel bailer was used to recover representative groundwater samples. Care was-taken to minimize sample agitation from the initial filling of the bailer to the transfer of the sample to the sample containers. Once the sample container was filled and capped, the bottle was inverted, tapped, and checked for head space bubbles. The sample container was identified and labeled with a unique designation, inserted into foam holders and placed in an ice chest cooled to 4°C for transport to the laboratory. � G