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i TABLE 2 .::....... :..: .. ems. . .:PERCOLATION'TEST, RESTS VQW.THUDISPOSAL AREA WITH CORRESPONDING APPLICATION RATES,IN GALLONS /FT i ,D z 42 INCH DEEP PERC TEST BORING: 41.7 n/inch / 0.472 gallons/ft'/day 144 INCH(12 FT)DEEP PERC TEST BORING 'n/inch / 1.029 gallons/ft/day 300 INCH(25 FT)DEEP PERC TEST BORING 5.6 nn/inch 1 1.029 gallons/ft/day Application Rates adapted from: California State Water Resources Con of and Guidelines for the Design of Sewage Systems. D. GROUNDWATER INFORMATION NLS§ 2.1, SSS§ 4.1. Groundwater depths and elevations throughout San Joaquin County are illustrated on ma .s blished by the County Flood Control and Water Conservation District. The most recent Lines of Equal Depth map (1999) indicates the groundwater depth to be approximately 75 feet. This groundwater depth corresponds with the sounding of the on-site domestic well. The 2003 Lines of Equal Elevation Map illustrates the groundwater directional flow to be generally in a north-northwesterly direction. Two well logs for domestic wells near the subject property illustrates varied geological strata of clay, sand and some shale. Standing well water levels measured in one of these wells in 1972 was found to be 68 fl; and in the other well in 1976 to be 76 fl. NLS§ 2.�,3.1` , SSS§2.1� 4.2. Since surrounding properties have been intensely farmed for several decades, the potentia�l:fo� i to contamination in the underlying groundwater can be considered significant. However,well water obtained directly from the aquifers underlying the property indicate high low-to-medium nitrate impact at 18 ppm nitrate,below one-half of the MCL at 22 ppm nitrate. This relatively low concentration may be attributed to the denitrification potential within the underlying aquifers. Groundwater research in the scientific literature suggests there may be significant denitrification potential within aquifers or saturated zones composed of a fine clay soil fraction. A potential rise in the water table elevation could occur from the cropland surrounding the property to the south,west and north, along with the surrounding partially concrete-lined O.T.D. Canal. Irrigation recharge can have an influence on the underlying and surrounding water table. The critical issue regarding the groundwater elevation is: 1.) There must be sufficient distance between the soil/effluent interface and the highest anticipated depth to groundwater for sufficient treatment of effluent to occur. This is generally accepted to be five feet for leachlines and 10 feet for sumps and seepage pits, and 2.) The water table cannot encroach upon the septic tanks, which may cause buoyancy. These two issues are inconsequential to this project. NLS§ 2.3, SSS X4.3 4.4 4.5. On October 14, 2007, the on-site domestic well was sampled under the following p oc e z 5 Chesney Consulting