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Aua- ^�y, 'w fim' ar.I$ 2-3 i Boreholes AL-3, AL-S, and AL-6 were destroyed by backfilling with a bentonite/cement slurry. Approximately 6 inches of concrete were placed on the hole for surface protection. Boreholes AL-1, AL-2, and Al-4 were completed as groundwater monitoring wells as described below. A monitoring well was installed in the boreholes by inserting a 2-inch-inside-diameter, Schedule 40 polyvinyl chlorideCIS (PVC) casing with 22 feet of 0.020-inch machine-slotted well screen attached to the bottom. The perforated casing extends approximately r feet below the water table and 2 feet above the water table in order to ctuations and to detect free-floating accommodate water table flu product. A bottom plug was installed. t To gravel pack the annular space of the well, coarse aquarium . sand was poured directly through the augers as the augers were gradually. removed from the borehole. A bentonite seal was placed immediately ab6ve the gravel pack, and the augers were then removed AJ from the borehole. The remaining annular space of each well was e filled with neat cement. Each well was completed. at grade with a r? : watertight utility box. The construction details for each well are ; included in Appendix B. Following installation, each well was developed using the mud pump on the rig until the water was relatively sediment-free. Each well was sampled on April 27, 1387, with a Teflon bailer equipped with a bottom-emptying valve. Prior to sampling, approximately 18 gallons of water (three well volumes) were removed, while monitoring { temperature, pH, and electrical conductivity, until these parameters f k had stabilized. The sample was then drained directly from the illiliter glass bottles with bottom valve into four 40-mTeflon-lined septums-and into a 1/2-liter plastic bottle containing nitric acid 3 preservative The samples were stored on rice from' the -time--o - groundwater collection through delivery to BC's laboratory. All g.