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i LEEDSHILL NEAKENHOFF, INC All samples were obtained under the supervision of a professional engineer A detailed boring log was kept at all times noting soil types encountered, using the Unified Soil Classification System, and noting moisture conditions, location, and depth for each sample. Copies of the boring logs are presented in Appendix A. All drill cuttings were containerized in 55-gallon drums with lids, and stored on site awaiting the results of the analytical testing. 3.2 MONITORING WELL INSTALLATIONS Two groundwater monitoring wells were installed b LH on November 21 and 28 1989. Hollow-stem angering techniques were used to install these two, 4-inch diameter monitoring wells at the locations shown on Figure 2. Monitoring Well #4 (MW4) is located near the southwestern corner of the property. Monitoring Well #5 (MW5) is located in the northeastern corner of the property. Each monitoring well was constructed of nominal 4-inch diameter, flush ,joint, Schedule 40 PVC. MW4 and MW5 were constructed to a total depth of approximately 63 feet each. Both wells were constructed with a thirteen foot length of well screen. The well screen had a slot size of 0.020-inch and was placed such that it extended in and above the depth at which water was first encountered during drilling operations. A uniformly sized sand pack was placed from the bottom of the well to a point approximately 1-foot above the top of the highest screen perforation. A 1'/,-foot bentonite pellet seal was placed above the sand pack, and a grout-cement mixture was placed in the remaining annular space to the ground surface. All drilling was conducted dry with no fluids added to the borehole or lubrication to the drilling equipment. All drilling equipment was thoroughly cleaned with high-pressure, hot water prior to use, to prevent potential cross- contamination. The PVC well casings were capped with lockable, water-tight seals, within a flush-mounted, water tight cover. The drill cuttings produced from each of the boreholes were containerized in 55-gallon drums with lids, appropriately labelled and stored on-site to await future disposal based on the result of the analytical testing. Well construction details are presented in Figure 4. Both monitoring wells were developed usin e block swab 9 a surge block/swabbing technique Surge block development involves pressurizing and depressurizing the well by moving a 4-inch rubber swab flange up and down within the well , forcing water in and out of the well screens. The agitation created by this development method helps to remove fine grained and/or suspended material from the well . After swabbing, ten to fifteen well volumes of water were bailed from each well to further develop these monitoring wells. The bailed water was containerized in 55-gallon drums with lids, appropriately labelled, and stored on-site to await disposal based on the results of the analytical testing. nQ4