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' 15 February 1999 AGE-NC Project No 96-0229 Page 3 of 9 2 14 Monitoring Well Completion Soil borings MW-7 MW-8 and MW-9 were single-completed and soil boring MW-10 dual - completed completed as ground water monitoring wells utilizing schedule 40, 2-inch diameter blank polyvinylchlonde (PVC) well casing and perforated, 2-inch diameter PVC well casing (0 020-inch slot) Each well was installed 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 Lonestar Lapis Luster sand (filter pack)was slowly poured down the annulus between the well casing and the inner wail 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 filter pack placement, a surge block was inserted into the well casing and lowered then raised (surged) repeatedly for approximately 10 minutes Approximately two to three feet of bentonite chips (annular seal) were placed above the filter pack and hydrated with clean tap water The remaining annular space from MW-7, MW-8 and MW-9 were backfilled with portland cement, the above mentioned well construction procedures were repeated from the top of the annular seal at well MW- 10 (dual-completed) As-built well-construction diagrams are included as Figures 7 through 10 2 1 5 Surveying of Monitoring Wells On January 11 1999, a California state-licensed survey engineer from Baumbach & Piazza, Inc I surveyed a reference point on the top of wells MW-7, MW-8, MW-9, MW-I OA and MW-1 OB to the nearest 0 01-foot relative to the City of Stockton Bench Mark Datum # 15 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 r 2 1 6 Well Development Activities On 15 October 1998, monitoring wells MW-7, MW-8 and MW-9 were developed utilizing a Teflon hand bailer and a two-stage submersible pump. on 19 October 1998, monitoring well Mw-10 was developed utilizing a Teflon hand bailer and a two-stage submersible pump Prior to well development activities on 15 and 19 October 1998, depths to ground water and total well depths from MW-7, MW-8, MW-9, MW-IOA and MW-IOB were measured to the nearest 0 O1-foot utilizing a Solinst water level meter Approximately 18 to 28 gallons of ground water were purged from MW-7,MW-8, MW-9,MW-I OA and MW-1013 Ground water was purged from each well until the water produced was visually Advanced GeoEnvironmental,Inc