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V F e the extent of nitrate impact to deeper groundwater(15 to 30 feet below grade) and rinking water aquifers, two other water samples were taken: The first sample was m the domestic well (Reference: 140 Klo Road)that serves the Central Valley office. A Well Log was not found at the Environmental Health Department for this ed in their September 10, 2001 memorandum to the Community Development Department, the Health Department expressed concerns regarding arsenic and Trichloroethylene (TCE) in the drinking water. Analytical test results reveal these two constituents to be Below Detection Limits (BDL). In addition, nitrate levels were also Below Detection Limits. Total Dissolved Solids (TDS) concentration was 1,536 ppm, which can be considered high. The depth of the well was measured with an electronic water level measurement device, and it appears the well is 75 feet deep. However, it was difficult to determine if the probe was touching the bottom of the well, or possibly the pump. The second water sample was taken from the on-site Monitoring Well #I after purging the well of 20_ gallons. The attached Well Log for this well produced by John P. Cummings& Associates, indicates the well screen extends from 13 feet down to 28 feet. Test Results (Reference: MW 1) indicate arsenic at Below Detection Limits (BDL). Trichloroethylene testing of this well was not required by the Health Department. Total Dissolved Solids concentration was 1,132 ppm, which is 26% lower than the TDS found in the deeper aquifers. Interestingly, the nitrate concentration was measured at 20.6 ppm,which is approximately 8 times lower than the water table nitrate concentration (21 ppm vs. 168 ppm). The test results are summarized as follows: DOMESTIC AND MONITORING WELL ANALYTICAL TEST RESULTS ANALYTE DOMESTIC WELLJANTAE MONITORING WELL #1 NITRATE Below Detectable Limits(BDL20.6 mg/L AS NO, Below Detectable Limits(BDLBelow Detectable Limits(BDL) Below Detectable Limits(BDLNot Tested per EHD 1,536 mg/L 1,132 mg/L GROUNDWATER DEPTH, GRADIENT AND VELOCITY The 1999 Lines of Equal Depth map produced by the San Joaquin County Flood Control District illustrates the groundwater depth under the subject properties to be 10 feet below grade. The static water level in the on-site domestic well was measured at 13 feet below grade and 12 feet below grade in MW#1. Lines of Equal Elevation map in 1999 indicates the groundwater directional flow to be north- northeast, and is very flat. The Groundwater Gradient Map produced by John P. Cummings from the on-site Monitoring Wells indicate the groundwater gradient also to be North 33' East. Consequently, at present, the Sh_pr e Army Depot can be considered cross-gradient to the subject properties. 7 CFiesney Consulting