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WZ1 INC 191 all over-drilled from five to 15 feet past the bottom of the screened interval to provide lithologic information at depth In each case, the over-drilled portions of the boreholes were backfilled with sodium bentonite pellets prior to well construction Screened intervals and borehole total depths for the monitoring wells are presented in Table 3 The annular space between the borehole wall and well screen in each boring was filled from the bottom of the screen interval to within 11 feet bgs with Clementina #3 filter sand A bentonite pellet sea[ was installed in each well from 11 to nine feet bgs, and a neat grout mixture of 94 pounds of Portland Type 11 cement and six gallons of clean, potable water was placed in each well from a depth of nine feet to ground surface A PVC slip cap was placed on the top of each well casing Well heads consisted of water- tight, locking, traffic rated, monitoring well vault boxes with a 10-inch wide cement pad to grade • Each monitoring well was developed immediately after the bentonite seal was installed and properly hydrated Monitoring wells MW-1 through -8 were developed with a five horsepower centrifugal pump Monitoring wells MW-9 and -10 were reportedly relatively low-yielding and were developed with a one and one-half-inch by three-foot stainless steel bailer Approximately 110 gallons of water was removed from MW-1 during its development The remaining monitoring wells were all developed by removing approximately 55 gallons of water from each well (McLaren, 1989a) Soil borings SB-1 through -5 were all drilled to a maximum depth of 17 5 feet bgs and were backfilled with the above-described cement grout mixture from total depth to ground surface All grouting operations were witnessed by a County Public Health site inspector • 19150011005 17