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4010#al fetlocks l", Page 2 Monitoring Well Installation Work Plan Valley Wholesale Drug Co.,Inc. �r Project No.989.2 November 21, 2001 +• 2.1 Water Table Monitoring Well Installation The two water table wells, MW-7 and MW-8, will be drilled using an 8.00-inch outside diameter continuous flight hollow stem auger owned and operated by V&W Drilling (C57# 658786). Soil cuttings will be placed in 55-gallon steel DOT approved drums and stored on site until their removal can be arranged. A professional geologist under the supervision of a LN licensed registered geologist will supervise all drilling, sampling, and well construction. The monitoring well will be constructed using 2.0 inch diameter PVC casing with flush threads. The screened interval will extend from five feet below grade to twenty feet below grade. Groundwater is expected to be located at approximately eight feet below grade. if a significant clay unit is encountered during the drilling of the well, the well may be seated no greater than 3 ft into that fine-grained unit. A #3 sand filter pack will surround and extend one foot above the 0.020" screened interval. A granular bentonite transition seal will be installed and hydrated. A surface seal will be achieved by pumping a neat cement grout (augmented with < 4%bentonite) via a tremie tube. The well will be secured with a locking watertight cap encased in flush mounted traffic rated well box. (See Figure 3 for a �. schematic of shallow monitoring well construction). After the well sealing materials have set (>24 hours), the well will be developed (using L, mechanical surging and pumping methods) until a clear stream of water is obtained. The well will be purged and groundwater samples collected no sooner than 48 hours after well development. All development and purge water will be containerized in 55-gallon DOT approved containers andstored on site until their disposition can be arranged. A competent surveyor will survey the top of casing measuring point for each well into an arbitrary plane. Lo 2.2 Deep Monitoring Well Installation We propose to install one deeper screened monitoring well (MW-101) which will be located a few feet from MW-1 (Figure 2, Site Map). The well boring will be drilled down to a total depth of approximately 40 feet. The exact �. depth of this well will be determined by the field geologist in conference with the registered geologist supervising the project. Soil cuttings will be placed in 55-gallon steel DOT approved drums and stored on site until their removal can be arranged. The well will be constructed using 2.0 inch diameter schedule 40 PVC casing with flush threads. A 2.5 foot screened interval will extend from 37.5-40 feet below surface grade (Figure 4 Deep Well Construction Schematic). A #12 sand filter pack will surround and extend 2.5 feet above the 0.010" screened interval. A three-foot granular bentonite transition seal will be installed and hydrated. A surface seal will be achieved by pumping a neat cement grout (augmented with < 4% bentonite) via a tremie tube. . The well will be secured with a locking watertight cap encased in a flush mounted traffic rated well box. (See Figure 4 for a schematic of deep monitoring well construction) w.. LO