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' Mr. Fran Forkas January 13, 1989 Page 2 discharges a portion of the treated waste into Dredger Cut which connects to White Slough about a mile west to the plant . White Slough, an east-west trending slough, extends. about 10 miles west to the San Joaquin River. Land surrounding the plant is owned by the City and leased for non-food crop agricultural purposes. The land is irrigated with reclaimed water from the plant . As shown on the figure, ground surface elevations around the plant are about 5 feet above mean sea level . The San Joaquin County Flood Control and Water Conservation District has been monitoring groundwater levels in its area for several years . Shown in Appendix A are copies of plots prepared by the County showing lines of equal groundwater elevation. The plots indicate a generally southerly or southsoutheasterly hydraulic gradient in the area of the treatment plant . As part of its planning efforts for the Peripheral Canal, the California Department of Water Resources (DWR) has also been monitoring groundwater levels in the area since 1968 . The locations of the DWR monitoring wells near the plant are shown on Figure 1 . The well identification numbers shown on the Figure are those assigned by DWR. Little information is available regarding the DWR wells . DWR reports that, due to the large number of wells constructed for the Peripheral Canal project, not all of the wells were logged. No logs were found for any of the DWR wells shown on the figure, however well depth and historic water level information was available. This data that was obtained .by the City from DWR and made available for preparation of this report . Well logs for the two potable wells that the City has on the site are provided in Appendix B. These wells are located near the south east corner of the treatment process facilities about 150 yards west of DWR well. 20-26A. Tables 1 and 2 contain data for 8 of the wells near the plant . Table 1 shows well construction information and historic water surface data for 5 wells oriented in a north-south axis through the plant . Table 2 provides similar data for 4 wells oriented on an east-west axis through the plant with one well, 20-14, being common to both tables . The period from February, 1978 through May, 1982 was selected for presentation because it includes the greatest number of water elevation measurements common to all wells. The data on Table 1 indicate a net southerly hydraulic -gradient across the plant which is consistent with the San Joaquin Flood Control and Water Conservation District data . Surface elevations in well 19-36, at the north, are. consistently higher than those in well 21-14A, at the south side. The data also indicate a hydraulic "mound" in the area of the holding ponds . The mound is also apparent in the data