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A. Underlying Water Table and Lake Water Test Results <br /> A groundwater sample (Sample ID: GWUFLF-Groundwater Under Future Leachfield)was retrieved from <br /> this exploratory boring for analysis. After retrieving the water table sample, the soil boring was <br /> backfilled with hydrated bentonite pellets. The water table sample from the exploratory boring and <br /> a lake water sample from the western shore line,reveals nitrate concentrations of 0 mg1(ppml. or <br /> Below Detectible Levels.,(BDU for both samples. The Maximum C ptaminant Level (MCL) for <br /> nitrate is 45 ppm (as nitrate). The alkalinity was comparatively hi at 403 ppm. or nitrification <br /> to occur, alkalinity must be consumed, as calculated below. <br /> Chloride was also quantified in the groundwater and found to be in an inexplicably, excessive <br /> concentration. High chloride in top iyoundwater may indicate impact from septic systems. Human <br /> wastes are generally high in chloride content and chloride is not absorbed by the soil, in the way <br /> clay soil traps the ammonium found in septic effluent. Chloride may,travel faster in the saturated <br /> zone than nitrate, and thus may be a first indicator of septic effluent contamination. However, <br /> there are no septic systems in this area. <br /> B. Supplied Domestic Water Test Results <br /> As referenced, the domestic water supply was available for analysis from the existing Brown <br /> Sand office well. The attached well log for this well indicates intervening strata of sand and <br /> clay, with water being drawn from 168 to 188 feet. Test results reveal te well water also <br /> contain no nitrate (BDL), and a ow alkalinity of <br /> C. Calculation of Alkalinity Requirement for Nitrification <br /> The nitrate-nitrogen loading calculations below are contingent upon the environmental factors <br /> required for nitrification to occur. Alkalinity in wastewater effluent plays a role in nitrification <br /> and is derived from the domestic water supply and the introduction of wastes to the wastewater. <br /> Nitrification consumes approximately 7.1 mgOf�dkdlinity for every milligram of ammonia- <br /> nitrogen(NH,-1) oxidized. Water chemistry for the existing domestic well for the project is 158 <br /> ppm, while the water table possesses 403 ppm. <br /> Nitrification of the average Total Nitrogen(TN)concentration of 88 mg/L is determined in Section <br /> IV C,below. Considering that ammonium typically composes 70%the -wiT?be <br /> �heSptal nitrogen in septic <br /> tank effluent: 88 mg/L x 80%= 70 mg/L NH4 N x 7.1 mg CaCO3mg/Lkalinity required. <br /> Therefore the alkalinity in the domestic water supply is deficient iapproximately 88 <br /> ppm,and nitrification may be inhibited,because there is insufficient alkalinity. <br /> D. Mounding Analysis <br /> Due to the fact that the groundwater is comparatively deep below the proposed location of the <br /> disposal area on top of the embankment, Mounding Analysis is not required or necessary. If it is <br /> L <br /> ned at some time in the future that mounding effects from the effluent encountering the <br /> g soil strata are preventing proper effluent treatment and disposal, the 100%replacement <br /> y have to be activated. This may occur prior to failure of the primary filter bed. <br /> Pa a-5- <br /> Chesney Consulting <br />