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A second critical issue regarding the groundwater elevation in combination with the five-foot separation distance,' that the water table cannot encroach up to the septic tanks; which may cause �2Jf huoyancy. This is discussed in the "Conclusions and Recommendations" Section of this Report. NLS§ 2.3, SSS§ 4.3,4.4,4.5. As referenced, the referenced well was sampled at the time of air 'r purging for development. Several casings of water were purged before sampling ensuring that aquifer formation water was sampled, and not stagnant water that had been standing in the well casing for several months. Two one liter plastic bottles were used for the water sample. The sample containers were placed in a cooled ice chest and then transported to A & L Western Agricultural Labs in Modesto, under the 7� attached Chain of Custody. The constituents tested were for those listed on the EHD Form for the Requirements of Transient-Non Community (TNC) Water Systems. Chloride concentration was tested and found to be comparatively low and even lower than the City of Tracy's water supply. Chloride was analyzed since medium-to-high groundwater chloride concentrations may indicate contamination from septic system effluent. Human wastes are generally high in chloride content. Chlorides travel exceptionally well in the soil environment, even faster than nitrate, and can be an excellent indicator of septic effluent pollution. A partial list of the required constituents to be tested is illustrated below in Table 4: K) TABLE 4 �VATER;AN " YSIS OF -ONSTITUENT`S�OF CONCERN ANALYTE LEVEL FOUND MAXIMUM CONTAMINANT LEVEL(MCL) Nitrate ND-Non Detect "45 mg/L(PPM) ' Total Alkalinity 88 mg/L No Standard i '.Chloride' 41 ►ng&:� '560 mg/L Iron 1598 ug/L 300 pg/L Manganese 244 g/L 50µgIL Calculation of Alkalinity Requirement for Nitrification The nitrate-nitrogen loading estimation on Page 12 is 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 aforementioned water well supply in addition to the introduction of wastes. Nitrification consumes approximately 7.1 mg of alkalinity for every mg of ammonia-nitrogen (NHQ N) oxidized. :N trification of the average Total Nitrogen (TN) concentration of 89.4 mg/L, as determined on Page 11 would require: 89.4 mg/L NH4-N x 7.1 mg' ;CaCO3 635 mg/L alkalinity. The alkalinity in the domestic water supply is presently 88 ppm, which may theoretically retard nitrification to an indeterminable degree. 6 Chesney Consulting