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ofIVcli _IfRNf8 . Mr. Sill Vizza 30 November 1993 Page 4 hydrocarbons. The results of field screening for organic vapors and of visual indications of staining are noted on the boring logs. Monitoring Well Installation Three two-inch diameter monitoring wells were installed and completed within an 8-inch diameter boring. The wells were constructed with a threaded end-cap placed at the bottom of a 15-foot length of Schedule 40 PVC well screen with 0.020-inch factory-cut slots. Approximately ten feet of this 15-foot length of slotted screen was positioned below the static water level to accommodate potential seasonal variations in groundwater levels. The remainder of the well casing consisted of Schedule 40 PVC blank casing. A two-inch diameter lockable cap was placed on the top of the well casing which was completed below grade inside of a watertight valve box All well casing materials were assembled above ground and placed in the well through the auger. Using the auger as a tremae pipe, 2/12 Lonestar sand was poured between the well casing and the auger to form the filter pack around the screened interval. The sand was extended approximately one foot above the top of the screen Above the filter pack, . approximately one foot of 1/4-inch bentonite pellets was placed as a transition seal. These pellets were hydrated with potable water and allowed to sit for approximately one hour. The remaining annular space was filled to just below the surface with a neat cement grout. Monitoring Well Development and Sam lin Once the monitoring well was installed and allowed to sit undisturbed for several days to allow the cement seal to harden, it was developed to remove accumulated fine materials from the well casing and filter pack After measuring the water level in the well, a translucent polyethylene bailer was used to visually inspect the groundwater surface for a product layer or sheen. No sheens or free product was detectable on water obtained from each of the three constructed monitoring wells. s. After inspection, the well was developed using a combination of bailing and surging techniques. The surging tool was moved up and down within the water column to agitate and remove fine sediments from the well. After approximately five minutes of surging, the bailer was lowered through the water column and raised vigorously to draw the fine material into the well for removal. Alternating surging and bailing were continued until the development water was relatively free of sediments Approximately 55 gallons of water was removed from each well during development. Development water was placed in 55-gallon drums, labelled and stored on site. • Upon completion of well development and after allowing for the aquifer to equilibrate another 5 days, the monitoring well was purged of standing water using a clean, disposable