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NLS§ 2.3, SSS§ 4.3, 4.4, 4.5. On January 24, 2008, the domestic well was sampled under the r�{,�.r following procedures: The well was pumped for one-half hour. Consequently, aquifer water and not stagnant well water was sampled. Well water was sampled from a sampling port on top of the discharge pipe from the well casing. A one pint plastic bottle was used for the nitrate analysis and three VOA vials with preservative for DBCP analysis. r' " After sampling, the sample bottles were placed in a cooled ice chest, then transported to A&L Western Agricultural Laboratory in Modesto under the attached Chain of Custody. As referenced, the constituents tested were for nitrate, and DBCP. The following Table summarizes the test results: TABLE 3 UNDERLYING GROUNDWATER ANALYSIS FROM THE ORIGINAL OLD WELL AND THE RECENTLY DRILLED NEW ON-SITE DOMESTIC WELL ANALYTE ON-SITE WELL Nitrate 12 ppm DBCP BDL Below Detectable Limits-Non Detect Calculation of Alkalinity Requirement for Nitrification The nitrate-nitrogen loading calculations on Page 10 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. y Alkalinity in wastewater effluent is derived from the domestic well water supply in addition to the introduction of wastes. Nitrification consumes approximately 7.1 mg of alkalinity for every mg of ammonia-nitrogen (NH4-N) oxidized. Nitrification of the average Total Nitrogen (TN) concentration of 103 mg/L would require: 103 mg/L NH,-N x 7.1 mg CaCO3 = 731 mg/L alkalinity. The alkalinity of the underlying aquifers supplying the domestic water supply is much lower than this concentration based upon previous analyses. Therefore, the low alkalinity concentration may theoretically inhibit nitrification to an indeterminable degree. E. SURFACE WATER INFORMATION Rainfall and indigenous subsurface soil water has caused the subsurface soils to be very moist, as observed in the 25 foot test boring. This subsurface soil water may create a dilution factor to the underlying water table receiving the downward migration of nitrate. In addition, since the groundwater directional flow is to the south, percolating rainwater runoff from the future structures north of the disposal area into the top aquifer mixing layer may create a dilution effect to the downgradient percolating septic system effluent. 5 __2j Chesney Consulting