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assembly. The well screen consists of . 01 machine-slotted schedule-40 PVC. A sand pack of # 2/12 filter sand was placed in the annular space from the bottom of the well boring to 2 feet above the top of the screened interval. The sand was slowly poured down the hollow-stem augers while the augers were slowly withdrawn. This method minimized the possibility of bridging and ' helped assure that the filter sand would surround the well casing before the native materials could collapse into the borehole. After the screened portion of the well casing was backfilled with filter sand, the hole was sealed with approximately 2 feet of 3/8-inch bentonite pellets followed by a slurry of neat cement grout. A traffic rated, bolt-locked, vault box with a cover indicating " Monitoring Well " was set in concrete to protect each the well and a water tight, locking well cap with lock was installed on each well casing. The traffic boxes were typically set about an inch above the existing ground surface to help ' divert surface water away from the well . 3 . 2 .2 Monitoring Well Development Wells MW-1 through MW-5 were developed between July 28 and 29, 1992 . Each well was checked for floating product prior to development using a dedicated polyethylene bailer. No floating ' product or sheen was noted in any of the wells . Each well was developed by surging and using a 4-inch O. D. PVC bailer until the water was clear of sand, silt, and turbidity or no change in improvement was noted. Development water was stored on site in 55-gallon DOT steel drums. The drums were labeled to show contents, suspected contaminant, date filled, company name, ' contact person, and telephone number. 3 . 2 . 3 Monitoring Well Sampling ' Groundwater samples were collected from all 5 wells on August 3 , 1992 . Prior to sampling, the wells were measured for depth-to- water to the nearest 0 . 01 foot using an electronic Solinst water level meter. A minimum of 3 repetitive measurements were made for each level determination to ensure accuracy. Each well was checked for floating product using a dedicated polyethylene ' bailer; no floating product, sheen, or odor was noted. Each well was purged a minimum of 4 well volumes with a 4-inch O. D. dedicated PVC bailer or until temperature, pH, and electrical ' conductivity of the purged water stabilized. After purging was completed, the water samples were collected with a 2-inch PVC disposal bailer. The samples were decanted ' into preserved; clean 40 ml glass vials with teflon lined screw caps; immediately sealed, and labeled to include: date, time, sample location, project number, and sampler. The samples were immediately stored on ice for transport to DHS certified Trace Analysis Laboratory. The samples were accompanied by chain-of- ' 6