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6 . 0 DETAILS OF SECTION III — FEASABILITY TESTS AND CORRECTIVE ACTION PLAN TASK I -INSTALL AN EXTRACTION WELL TO BE USED FOR THE PUMPING AND DUAL-PHASE TESTS In order to obtain the best possible data, ASE proposes installing a 6-inch diameter pumping well for the pumping and duel-phase tests This well will be constructed using a drill rig equipped with 12-inch diameter hollow-stem augers The well will be constructed within the hollow stem augers using 6-inch diameter flush-threaded, schedule 40, 0 020-inch slotted PVC well screen and blank casing The wells will be screened between approximately 4 and 19-feet bgs to monitor the first water bearing zone encountered The well casing will be lowered through the augers and #2112 filter pack sand will be placed in the annular space between the well casing and the borehole from the bottom of the boring to approximately 1-foot above the screened interval Approximately 0 5- feet of bentonite pellets will be placed on top of the sand pack prior to placing the cement sanitary seal The bentonite will be hydrated with water prior to placing the cement sanitary seal Cement mixed with 3 to 5 percent bentonite powder by volume will be used to fill the annular space between the bentonite layer and the surface to prevent surface water from infiltrating into the well and to prevent conduits for the migration of contamination from shallow groundwater into deeper zones The cement seal in this shallow well will be placed by simply pouring the seal into the boring without using a tremie pipe The well head will be protected with a locking well plug beneath an at-grade, traffic-rated well box (See Figure 5 - Typical Monitoring Well) The 6-inch diameter of this well will allow enough annular space for pumps and an interface probe to be placed in the well at the same time and will allow greater pumping rates TASK 2 -CONDUCT A STEP DRAWDOWN TEST A step drawdown test will be conducted to estimate sustainable pumping rates in the shallow water-bearing zone for a constant rate pumping test Pumping rates for this test will be determined in the field but rates of 0 5, 1, 2 and 4 gallons per minutes are planned Higher pumping rates will also be used if pumping at higher rates can be sustained Data will b e • collected manually as well as with a data logger and pressure transducer Groundwater produced during this test will be stored on-site in sealed a n d labeled 55-gallon steel drums until off-site disposal can be arranged Frank's One Stop Workplan — June 2000 -17-