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December 14,2005 <br /> NOA Project Number: E05116B <br /> V <br /> 3.5 Nitrate Loading Scenario <br /> A nitrate loading scenario was performed to determine the impact from the proposed project (Plate <br /> V10). The scenario utilizes the variables discussed previously which represent the estimated <br /> conditions and uses associated with this project. The following table presents a summary of the <br /> nitrate loading calculation. <br /> Table 3. <br /> Summary of Nitrate Mass Balance Analysis. <br /> r, <br /> Ecres Average Daily Effluent Concen- Leachfield Deep Percolation of <br /> (A) Flow(Q) (Table 1) tration(Nw) Denit�- Rainfall(R) <br /> (gpd) (mg/L-l) cation(d) (Plate 9) (in.) <br /> 5 560 45 25% 5.76 <br /> taminant level(N1CL) for nitrate in drinking water is 10 mg/L-N. <br /> /3.6 Impact of Nitrate Loading to Nearby Water Sources <br /> The result of the nitrate loading balance indicates that the proposed development will not potentially <br /> cause a buildup of nitrate in the ground water above 10 mg/L-N over the long term. The nitrate <br /> loading addresses domestic septic usage from each 5-acre parcel. According to the Hantzsche and <br /> Fennemore equation and assumptions discussed previously, there is a potential for a buildup of <br /> nitrates in the ground water to 7.8 mg/L-N which is below the drinking water maximum <br /> contaminate level of 10 mg/L-N. <br /> 4.0 DISCUSSION OF NITRATE LOADING RESULTS <br /> i. ✓4.1 Total Nitrate Impact <br /> According to the Hantzsche and Fennemore equation and approach there is a potential for a <br /> ` buildup of nitrates in the ground water to 7.8 mg/LN. The actual impact to ground water may <br /> actually be less than estimated. The equation assumes full build out (two residences) and full <br /> occupation of the property over the life of the property which is a conservative estimate. <br /> PThe well water test for nitrates indicated a result of 21.7 mg/L-NO3 which is well below the MCL of <br /> 45-mg/L. It appears that the aquifer at which the well is drawing is not experienced elevated nitrate <br /> concentration in ground water. <br /> 4.2 Methods of Mitigation <br /> No mitigation is proposed. <br /> 6 <br /> ti <br /> '404 <br />