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On May 1, 1998, Morrow Surveying, a California-licensed land surveyor (#5161), surveyed each <br /> of the newly installed wellheads and all of the previously installed wells The surveyor located <br /> each of the wells and measured the elevation of the top of well casing and the nm of the stove- <br /> pipe or street box to the nearest 0 01 foot, referenced to the City of Stockton Bench Mark#22 <br /> The surveyor's report is included as Appendix D <br /> 2 2 4 Groundwater Monitoring, Sampling and Analysis <br /> On May 1, 1998, Ramage Environmental monitored and sampled the newly-installed wells (MW- <br /> 6 and MW-7) and the deep soil vapor extraction wells (VW-1D and VW-21D) Prior to purging, <br /> depth-to-groundwater was measured to within 0 01 foot in each well using a Waterline® water <br /> level indicator <br /> After measuring depth-to-groundwater, each of the wells was purged with an electric downhole <br /> (Grunfos) pump and sampled The newly installed wells (MW-6 and MW-7) were sampled after <br /> well development and full recharge The existing wells (VW-1 D and VW-2D) were sampled after <br /> at least three well casing volumes had been extracted and/or after groundwater temperature, pH <br /> and electrical conductivity values had stabilized Groundwater was sampled from the wells using <br /> disposable bailers and laboratory-supplied containers Each sample container was labeled, <br /> packaged in an iced cooler, transported under chain-of-custody documentation to AEN for <br /> analysis AEN analyzed each of the groundwater samples for TPH-as-Gasoline, BTEX and <br /> MTBE by modified EPA Method 8015/8020 <br /> 2 2 5 Waste Disposal <br /> Waste soil generated during drilling was stockpiled on-site and sampled for disposition <br /> Analytical results of sod samples collected during drilling indicated that the waste sod did not <br /> contain detectable concentrations of gasoline hydrocarbons As such, the waste sod stockpile <br /> was disposed of on-site <br /> Equipment nnsate wastewater and purge wastewater from the development of the newly- <br /> installed wells was contained in 55-gallon drums pending the results of the groundwater sample <br /> analyses Since the groundwater samples collected from MW-6 and MW-7 did not contain <br /> detectable concentrations of gasoline hydrocarbons, the wastewater was disposed of on-site <br /> The groundwater purged from VW-1 D and VW-2D was also contained in separate 55-gallon <br /> drums Since gasoline hydrocarbons were detected in the groundwater samples from these <br /> wells, the wastewater will be properly disposed or recycled <br /> i <br />