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' 25 April 2000 • AGE-NC Project No, 98-0520 Page 3 of 7 recorded on the boring logs. Soil was visually described in accordance with the Unified Soil ' Classification System (Boring Logs, Appendix A). 3.4. GROUND WATER MONITORING WELL COMPLETION ' Pilot borings MW-I through MW-5 were completed as ground water monitoring wells using two- inch diameter PVC casing with 0.020-inch slotted screen installed from 35 feet to 15 feet bsg and with blank casing extending to the surface. The filter pack(No. 3 Lonestar sand)was installed from ' 35 feet to approximately 12 feet bsg.The wells were then developed using a surge block to settle the sand pack. A nominal 3-foot bentonite pellet plug,was then installed above-the filter pack and hydrated.The wells were then grouted to near the surface with portland cement. Water-tight,traffic- rated well boxes were then installed over the wells. The ground water monitoring well design is presented in Figure 4. 3.5. MONITORING WELL PURGE PROCEDURES t• On 15 December 1999, a Solinst water level meter was used to measure the depth to ground water `in the five wells relative to the tops of the well casings. The ground water elevations and gradient were determined from this data(Table 1). After recording water level measurements, a two-stage submersible pump was used to purge each monitoring well of standing water. Approximately 9 gallons of water were removed from each well (approximately 3 well casing volumes). Ground water temperature, pH and conductivity were measured at 3-gallon intervals during the purge process using a Hydac water analyzer. Field data sheets are included in Appendix B. Purged water was stored on site in labeled, 55-gallon DOT- approved drums. ' 3.6. COLLECTION OF GROUND WATER SAMPLES ' Water samples were collected from each purged well using new disposable plastic bailers. Each water sample was transferred into 40-m1 VOA vials containing 0.5 ml 18% hydrochloric acid as a sample preservative,and into 1-liter glass amber bottles without apreservative.After collection,the ' samples were properly labeled,placed in a chilled container and transported under chain-of custody to Alpha Analytical Laboratories, Inc. The samples were analyzed for: ' 0 TPH-g and TPH-mo in accordance with EPA Methods 5030/8015m and 3550;- i + Volatile aromatics including BTEX with MTBE in accordance with EPA Method 60218020; Advanced GeoEnvironmental,Inc.