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1 - ' 01 October 2004 . AGE-NC Project No 95-0173 ' Page 2of10 ' 2 1 WELL MONITORING AND EVACUATION PROCEDURES On 06 July 2004, the depth to ground water was measured at each well from the tops of the well casings to the nearest 0 01-foot, utilizing a Solinst water level meter Ground water elevation at the site was calculated by subtracting the measured depth to ground water from the surveyed well casing elevations (Table 2) Ground water elevations were plotted and contoured on a scaled site map ' (Figure 3) After water levels were measured, approximately 3%z to 9 gallons of ground water (a minimum of three casing-water volumes per well)were evacuated (purged) from single-level monitoring wells MW-1 through MW-12,and air sparge wells AW-lA and AW-2A utilizing disposable polyethylene bailers Multi-level monitoring well MW-13 (A-C) and air sparge wells AW-IB and AW-2B 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 Watera Hydro-Lift H pump equipped with a mechanical arm was utilized to surge the polyethylene hose Approximately 2% to 4 gallons of ground water (a minimum of three casing- water volumes per well) were purged from multi-level wells MW-13 (A-C), and approximately 13 ' • to 18% gallons were purged from air sparge wells AW1-B and AW-2B, respectively Temperature,pH and conductivity were measured for stabilization at regular purge-volume intervals ' from each well using the Oakton water analyzer Field data and logs are in Appendix B Purged ground water from the above wells was transferred to 55-gallon drums and stored on-site in an area lacking general public access 2 2 GROUND WATER SAMPLING Following well purging,ground water levels in the wells achieved a minimum of 80 percent recharge prior to sample collection Subsequently, ground water samples were collected from each purged ' well utilizing new,disposable polyethylene bailers and transferred into 40-m1 EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid as a sample preservative, ground water samples were collected from multi-level well MW-13 (A, B and C) and air sparge wells AW-1B and AW-2B and poured directly into the 40-m1 VOA vials utilizing the Watera hose bailer 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 • Advanced GeoEn viron mental,Inc I