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RE[AIlCX�-[fRJYER <br /> ' Mr. Bill Vizza <br /> 30 November 1993 <br /> ' Page 4 <br /> hydrocarbons. The results of field screening for organic vapors and of visual indications <br /> {, of staining are noted on the boring logs. <br /> Monitoring Well Installation <br /> Three two-inch diameter monitoring wells were installed and completed within an 8-inch <br /> diameter boring. The wells were constructed with a threaded end-cap placed at the bottom <br /> ' of a 15-foot length of Schedule 40 PVC well screen with 0 020-inch factory-cut slots. <br /> Approximately ten feet of this 15-foot length of slotted screen was positioned below the <br /> F' static water level to accommodate potential seasonal variations in groundwater levels. The <br /> remainder of the well casing consisted of Schedule 40 PVC blank casing. A two-inch <br /> diameter lockable cap was placed on the top of the well casing which was completed below <br /> grade inside of a watertight valve box. <br /> All well casing materials were assembled above ground and placed in the well through the <br /> auger. Using the auger as a tremle pipe, 2/12 Lonestar sand was poured between the well <br /> casing and the auger to form the filter pack around the screened interval. The sand was <br /> extended approximately one foot above the top of the screen. Above the filter pack, <br /> approximately one foot of 1/4-inch bentonite pellets was placed as a transition seal. These <br /> pellets were hydrated with potable water and allowed to sit for approximately one hour. <br /> The remaining annular space was filled to lust below the surface with a neat cement grout <br /> r, Monitoring Well Develoi)ment and Sampling <br /> ' Once the monitoring well was installed and allowed to sit undisturbed for several days to <br /> allow the cement seal to harden, it was developed to remove accumulated fine materials <br /> from the well casing and filter pack After measuring the water level in the well, a <br /> translucent polyethylene bailer was used to visually inspect the groundwater surface for <br /> a product layer or sheen No sheens or free product was detectable on water obtained from <br /> each of the three constructed monitoring wells. <br /> After inspection, the well was developed using a combination of bawling and surging <br /> techniques. The surging tool was moved up and down within the water column to agitate <br /> and remove fine sediments from the well. After approximately five minutes of surging, the <br /> bailer was Iowered through the water column and raised vigorously to draw the fine <br /> material into the well for removal Alternating surging and bailing were continued until <br /> 1' the development water was relatively free of sediments. Approximately 55 gallons of <br /> water was removed from each well during development Development water was placed <br /> in 55-gallon drums, labelled and stored on site <br /> Upon completion of well development and after allowing for the aquifer to equilibrate <br /> another 5 days, the monitoring well was purged of standing water using a clean, disposable <br />