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' Mr Harlan Knoll September 20, 1993 Page 4 ' Selected soil samples from each boring will be analyzed for TPHd and BTEX using EPA Method 8015 (modified) and EPA Method 8020, respectively These methods are recommended by the California Environmental Protection Agency (Cal EPA), and will be ' performed by a Cal EPA-certified environmental laboratory ' Monitoring Well Construction Monitoring wells will be constructed in two selected borings using flush-jointed, 2- in inner diameter, schedule 40 polyvinyl chloride (PVC) casing No chemical cements, glues, or solvents will be used in well construction The base of each well will be fitted I with threaded PVC plugs The screened portion of the well will consist of factory- perforated casing with 0 020-in-wide slots The well screen will be set through the augers ' and will extend from the total depth of the bonngs to approximately 5 to 8 ft above the groundwater surface at the time the well is installed This will allow sampling near the air- water interface in the formation during seasonal fluctuations of groundwater elevations The annular space of each well will be packed with sorted #3 Monterey san dtoa point approximately 1 to 2 ft above the top of the perforated casing A 2-ft thick plug consisting of bentonite pellets or chips will be placed above the sand in each well and hydrated to restrict entry of cement into the sand pack The remaining annulus will be Ibackfilled with a mixture of neat cement and powdered bentonite (<5%) to grade A cast-aluminum utility box with a sheet metal apron will be placed over the well head and set in concrete flush to slightly above the surrounding grade Utility boxes such as these have a watertight seal to protect against surface-water infiltration, the cover to the box is secured by countersunk bolts The well head will be fitted with a locking well cap to protect against unauthorized disturbance of the well This design discourages vandalism and reduces the possibility of accidental disturbance of the well The existing well MW-1 was not installed with this type of watertight utility box The existing box will be removed and replaced with a more secure cover Groundwater Sampling After each well is constructed, a subjective inspection will be performed by lowering a clean bailer to the groundwater surface and retrieving a groundwater sample The water will be examined for floating product, sheen, or odor If floating product is detected, the well will not be developed or sampled If all three wells do not show floating ROGER I 323-001 ww FMT T ASSOCIATES