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1 1 • • <br />' 17 Maich 1996 <br /> AGE-NC Project No 95-0128 <br />' Page 4 of 8 <br />' in monitoring wells MWA through MW-3 and vapor well VW-1 <br /> After ground water depth measurements, approximately 20 to 30 gallons of water (minimum of 3 <br /> well volumes) were removed from each well using a stainless steel Grondfos submersible pump <br /> Temperature,pH and conductivity were measured at 5-gallon intervals using an ICM water analyzer <br /> Monitoring well stabilization data and field sheets are included in Appendix C Purged water was <br /> temporarily stored on-site in 55-gallon DOT H-17 storage drums <br /> 2 3 2 MONITORING WELL DEVELOPMENT AND PURGING, FEBRUARY 1997 <br /> On 03 1~ebivary 1997, a Solinst water level metes was used to measure the depth to ground water in <br /> each well relative to the top of the well casings <br />' After ground water depth measurements were collected,monitoring wells MW-4 tluough MW-7 and <br /> vapor well VW-1 weie purged using a stainless steel Grondfos submersible pump Approximately <br /> 25 gallons of water were evacuated from each well Temperature, pH and conductivity were <br /> . aneasuied at 5-gallon intervals using an ICM model 52200 water analyzer Stabilization data and <br /> field logs are included in Appendix D <br /> 1 2 3 3 GROUND WATER SAMPLE COLLECTION <br /> IUpon stabilization, a water sample was collected from each purg,.d well using a new, clean, <br /> disposable plastic bailer Immediately upon retrieval, samples were transferred into chilled 40-m1 <br /> EPA approved VOA vials, pieserved with hydrochloric acid and a 1-liter amber bottle Sample were <br /> placed in a chilled container and transported under chain-of-custody to Alpha Analytical L <br /> Laboratories, Inc. (AAL) in Ukiah, California <br /> rAll samples weie analyzed for TPH-g,TPH-d,BTE&X and MTBE in accordance with EPA methods <br /> 5030/8015m and 602 MTBE confiimation was performed using EPA method 8240 <br /> 40 FINDINGS <br /> 41 STRATIGRAPHY <br /> During the installation of monitoring wells MW-4 through MW-7, tan to brown, moist, silty clay <br /> was encountered from the surface grade to depths of approximately 15 feet bsg in each boring Tan <br />`. to brown, dry, sandy silt was encountered from 15 to 35 feet bsg Gray, silty, poorly graded (coaise- <br /> i <br />