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IAX� GEOMATRIX The borehole for well TW-1 was advanced to a depth of 25 feet bgs and a soil sample (TW-1-5.5) was collected from the boring at a depth of 5.5 feet bgs for laboratory analysis. The soil sample was analyzed by AEN for BTEX using EPA Method 8020, PAHs using EPA Method 8310, and TEPH using EPA Method 8015M quantified against a San Joaquin Valley crude oil standard provided by CPL. Following completion of the boring, a temporary well was constructed of 2-inch diameter Schedule 40 polyvinyl chloride (PVC)blank casing and 12 feet of factory slotted PVC well screen with 0.02-inch slots. Well TW-1 was screened across the water table between 13 and 25 feet bgs. The sand filter pack(Lonestar Lapis Lustre 2/16) was placed from the bottom of the boring to 2 feet above the top of the screen. A 1-foot bentonite pellet transition seal was placed above the sand filter pack. A cement-bentonite grout mixture (3 to 5 percent bentonite powder) was used to fill the remaining annular space under the supervision of a PHS-EHD representative. The temporary well was capped with a 2-inch expandable water-tight cap, locked and completed at grade level with a 12-inch traffic-rated well box. On 17 June 1997, well TW-1 was developed in accordance with Geomatrix protocols. The well was developed using a combination of bailing and surging to remove sediments that accumulated in the casing during well installation, consolidate the filter pack, and enhance hydraulic communication between the formation and the well. Well TW-1 was developed until the recovered water was clear(less than 30 NTU). Groundwater samples from well TW-1 were collected on 17 and 27 June and 31 July 1997. Prior to sampling,well TW-1 was purged until water quality parameters such as pH, temperature, and specific electrical conductance stabilized. Well TW-1 was resampled on 27 June 1997 because the contract laboratory lost some of the water samples collected on 17 June 1997. Groundwater samples were analyzed for BTEX using EPA Method 8020, PAHs using EPA Method 8310, TPPH using EPA Method 8015M quantified against a gasoline standard, and IAWPD0CS\4097TADDLINVB.D0C 6