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i 1 I 18 November 2004 AGE-NC Project No 97-0301 ' Page 2 of 6 2 1 WELL MONITORING AND PURGING ' . Soo a I rigs a r,-M-mac (,I Va 101 APP" On 17 June 2004, depth to ground water was measured in each well from the top of the well casing to the nearest 0 01-foot utilizing a Solinst water level meter It was noted that the probe would not pass below 37 feet in well MW-9A On 18 June 2004, single-completion monitoring wells MWA through MW-7 and multi-level monitoring wells MW-8 through MW-12 were purged by lowering and raising a 3/8-inch outer diameter, length-discrete polyethylene hose equipped with a ball-valve water tip through the top ' chambers into the specific water-charged screened section A Waterra Hydro-Lift II pump equipped with a mechanical arm was utilized to surge each well with $/a-inch diameter polyethylene hose Approximately 3 to 27 gallons of ground water(a minimum of three casing-water volumes per well) were purged from single-completion wells MW-1 through MW-7 and approximately%2 to 3 gallons were purged from multi-level wells MW-8 through MW-12 Temperature,pH,and conductivity were measured for stabilization at regular purge-volume intervals from each well using an Oakton water analyzer Field data and logs are included in Appendix A All purged ground water was transferred to Department of Transportation (DOT)-approved model 17H 55-gallon drums and stored on-site in an area lacking general public access 1 � I 2 2 GROUND WATER SAMPLING After each well was purged, ground water levels were re-measured to verify the amount of ground I water recharge Upon achieving at least 80% ground water recharge, samples were collected from ' wells MW-1 through MW-12 utilizing the techniques described above in purging each well Ground water samples from each well were transferred into three 40-milliliter(ml) EPA-approved volatile ' organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid solution as a sample preservative and one 1-liter amber bottle without sample preservative Care was taken to ensure that visible air bubbles were not present in the vials after filling and capping Ground water sample ' containers were labeled with the well designation, date, time, and sampler's initials 2 3 LABORATORY ANALYSIS OF GROUND WATER SAMPLES Following collection and labeling,each ground water sample was logged on a chain of custody form, ' placed in a chilled container, and transported to Cal Tech Environmental Laboratories (CTEL), a California Department of Health Services (DHS)-certified laboratory, for analysis for • Total petroleum hydrocarbons quantified as gasoline,diesel,kerosene,and motor oil(TPH-g, . TPH-d, TPH-k, and TPH-mo, respectively) by EPA Method 8015M, and ' ' Advanced GeoEnvironmental,Inc