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APPENDIX A Page 2 thick bentonite seal was placed in the well annulus above the filter pack. A grout seal consisting of a Portland Cement and bentonite slurry was tremied into the well annulus above the bentonite seal. Each well was completed with a locking well: cap and a flush-mounted, traffic-rated well cover. As-built well diagrams are presented on Plates 21 through 23. Monitorin2 Well Development, Purging and Sampling w. After well construction was completed, the water level in each well was measured with an electronic well sounder and the wells were checked for free product using a clear bailer. The wells were subsequently developed using a vented surge block. Approximately three well volumes of water were then removed by hand bailing until temperature, pH and conductivity readings stabilized and/or the water cleared of sediment. After a minimum of 24 hours from the time of development, the water level in each well was measured, and the water checked for visual signs of free product using a clear bailer. Approximately three to five additional well volumes of water were purged using a clean bailer until temperature, pH, and conductivity �.�., readings stabilized and/or the water cleared of sediment. The water samples were then collected using new polyethylene disposable bailers. Water from the bailers was decanted into appropriate sample containers provided by the laboratory. The samples were immediately placed in an ice-chest with ice, along with a travel blank, and submitted under chain-of-custody to a California-certified laboratory for analysis of Total Petroleum Hydrocarbons (TPH) using EPA method 8015, and Benzene, Toluene, Ethylbenzene and Total Xylenes (BTEX) using EPA method 602. The travel blank provided by the laboratory also was analyzed for TPH and BTEX. Equipment was cleaned prior to development and purging of each well with a solution of La trisodium phosphate and distilled water to minimize the potential for cross contamination. All water removed during development and purging operations was stored in sealed, labeled 55- gallon drums. ' Subsequent to installation and completion, well locations and elevations were surveyed by a `'f California-licensed surveyor to aid in the determination of the hydraulic gradient and flow direction. WALLACE•KUHL &ASSOCIATES INC.