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DEC 07 SG 1::8 LEV IHE-FF E, H. B. p .3 LEVINEFRICKE survey for well N-16 was used as the datum for the re-survey and the top of steel casing for all the remaining wells were surveyed relative to the N-16 bench mark. These new elevations are listed in Table 1 along with the elevation of the top of PVC well casing, where PVC casing exists. Water levels and product thicknesses in existing wells were also measured on the same day using a water-sensitive probe coated with gasoline gauging paste. The depth-to-water, product thickness, calculated water elevations, and calculated equivalent water elevations incorporating the thickness and density of petroleum on the water table are listed in Table 1. Hydraulic Testing Hydraulic slug testing of three wells (N-6, N-7, and N-16) Was conducted on July 19, 1988 to assess the hydraulic conductivity of shallow sediments. A slug of water was withdrawn from each well using a clean Teflon bailer. Prior to withdrawal, a pressure transducer was inserted in the well and timed measurements of the hydraulic reaction (water level) in the well were electronically recorded. The data from the tests were evaluated using a computer code developed by Dr. Mansour sepehr of Levine•Fricke that evaluates four conventional hydraulic analyses. The code solves the Theis equation using the methods of: Hvorslev (1951), Ferris and Knowles (1963), Cooper, Bredehoeft, and Papadopulos (1967), and Bouwer (1978). The data from the slug tests are listed in Appendix A along with the resulting hydraulic conductivity values calculated for each of the methods. DATA EVALUATION Water elevations were recalculated using product thickness to calculate their equivalent potentiometric head. These data were mapped and contoured to estimate direction of ground-water flow and to calculate hydraulic gradients (Figure 2). Flow directions as suggested by Figure 2 are convergent toward Cook Road. The slough appears to be recharging ground water on both the north and west sides of the Arcady site. The local low at Cook Road may be caused by irrigation of nearby fields or by perimeter subdrains at the edges of the farm fields. The water-elevation data are supported by the evidence from petroleum product on the water table. The product does not appear to have migrated away from the area previously reported to have been affected in December 1987 by the Mark Group (see previous reports).