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(4] Cont. The percolation test pit on Parcel 2 was set at 13.5 feet below grade, where a silty sand was encountered during excavation. Perc test pit for Parcel 3 was set at 15.5 feet below grade where a silty sand was also encountered. The test pit for Parcel 4 was dug to 8 feet below grade where a much higher sand content soil with a greater porosity was encountered. Water seepage was high enough in this test pit that an accurate perc rate could not be determined. The percolation test results show comparatively fast rates considering the silty sand soil structure Ott the test depths, and will be discussed in the Conclusions section of this report. Our percolation tests were performed in accordance with San Joaquin County Department of Environmental Health regulations. The attached Field Test Data Sheets illustrate the perc test results. 151 LOCAL GROUNDWATER AND SURFACE WATER INFORMATION The groundwater is located at approximately 100 ft below grade according to maps published by the Flood Control District. There was no evidence of a perched water table condition during our percolation test boring procedures, although the soil was fairly moist. There are no nearby surface waters which may be impacted from septic effluent. However, the owner may build a tailwater pond on Parcel 3, but the location should be opposite the septic system. The Environmental Health Department stipulated the domestic wells at 12556 and 12352 South Van Allen Road be tested for the pesticide DBCP and nitrates. The results indicate the well at 12352 Van Allen has a nitrate concentration of 50 ppm which is over the maximum contaminant level of 45 ppm. The well at 12556 Van Allen has a nitrate concentration of 24 ppm. Both wells were non-detect for DBCP. nr (0 J1 Q-lity Control Inspection