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11ft/ .1.01 FFam pth to the water table was measured in the test boring at approximately 10 feet below grade. A groundwater sample was retrieved from this soil test boring for analysis. After retrieval, a bag of bentonite pellets (two cubic feet)was poured down the boring, which a bentonite plug from the bottom of the boring to three feet below grade. Tap water was ed to hydrate the pellets. Cuttings from the boring were then used to backfill the remaining volume. Static groundwater depth of 10 feet as determined in the test boring corresponds exactly with the 1999 Lines of Equal Depth to Groundwater map. From the 1999 Lines of Equal Elevation of Groundwater, the groundwater elevation is approximately 32 ft MSL. The 1992 Lines of Equal Elevation of Groundwater show the groundwater to beat 30 ft MSL. Directional flow appears to be gradual toward the west, but with a dramatic decline to the northwest. Therefore, the predominant flow may be in the northwest direction. A. Underlying Groundwater Test Results The groundwater sample from the exploratory boring reveals a nitrate concentration of 62 mg/L (ppm), which is approximately 1.5 times the Maximum Contaminant Level (MCL) of 45 ppm(as nitrate.) The pH was taken in the field and found to be slightly alkaline at 7.3. Alkalinity was comparatively low at 145 ppm. Total Kjeldahl Nitrogen(TKN) is a measure of the organic and ammonium fractions of Total Nitrogen. Test results show 1.6 mg/L of TKN which indicates either, or both, of these nitrogen fractions are present in the water table. B. Supplied Domestic Water Test Results It is our understanding that the project will receive domestic water from the City of Manteca. Therefore, a water sample was obtained from the Kamps Propane Company adjacent to the north of the subject property. The domestic water source indicates a high nitrate concentration of 34 mg/L and a comparatively high TDS of 484 mg/L. Total Alkalinity within the domestic water is relatively low at 217 ppm and cannot account for the observed and required alkalinity needed to be consumed during the nitrification process. There must be a subsequent loss of 7.1 mg of alkalinity in the wastewater for every milligram of ammonium oxidized to nitrate. Consequently, alkalinity must be coming from the soil environment and the wastewater effluent. Calculation of Alkalinity Requirement for Nitrification All of the nitrate-nitrogen loading calculations below are contingent upon the environmental factors required for nitrification to occur. These conditions include soil pore-space oxygen content, soil temperature, pH, electrical conductivity, organic matter, cation exchange capacity, and alkalinity. Alkalinity in wastewater effluent is derived from the domestic water supply in Page-4- Chemey Consulting