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18 September 1998 AGE-NC Project No 95-0173 ' Page 3 of 8 2 14 Monitoring Well Completion Soil borings MW-10, MW-11 and MW-12 were completed as ground water monitonng wells utilizing 2-inch diameter, schedule 40, blank polyvinyl chloride (PVC) casing and 2-inch diameter screened PVC casing (0 020-inch slot) Each well was completed by placing the PVC well casing assembly through the hollow stem of the augers to the total depth of the boring The augers were incrementally raised as #3 Lonestar Lapis Luster sand(filter pack) was slowly poured down the annulus between the well casing and the inner wall of the hollow stem auger The filter pack was placed adjacent to the screened casing from the bottom of the boring to a point approximately two feet above the top of the screen Following placement of the filter pack, a surge block was inserted into the PVC casing and was Iowered then raised (surged)repeatedly for approximately 10 minutes Thereafter, the depth to the top of the filter pack was measured and bentonite chips placed above the filter pack and hydrated with clean tap water to serve as an annular seal The remaining annular space was sealed with portland type 11 cement As-built well construction diagrams are included as Figures 3, 4 and 5 lie 2 1 5 Surveying of Monitoring Wells On 15 July 1998, a California licensed survey engineer from Baumbach & Piazza, Inc surveyed a reference point on the top of each ground water monitoring well at the site to the nearest 0 01 foot relative to the City of Stockton Bench Mark Datum# 25 The results of the monitoring well survey are contained In Table 2 The surveying report (Baumbach & Piazza Job No 9797) is presented in Appendix B 2 1 6 Well Development On 17 July 1998, monitoring wells MW-10 through MW-12 were developed utilizing a two-stage submersible pump Ground water was purged from each well until the water produced was essentially sediment free Approximately 20 gallons of ground water were purged from each monitoring well, monitoring well M W-11 produced approximately 1 gallon of ground water prior to being pumped"dry" Purged ground water was contamenzed in properly labeled D O T-approved model 17H 55-gallon drums and was stored on-site in an area lacking public access. 2 2 QUARTERLY MONITORING AND SAMPLING ACTIVITIES On 17 July 1998, quarterly ground water monitoring and sampling was performed Ground water Advanced GeoEnvironmentel,Inc