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December 14, 2005 <br /> NOA Project Number: E05116B <br /> 3.5 Nitrate Loading Scenario <br /> A nitrate Ioading scenario was performed to determine the impact from the proposed project (plate <br /> 10). The scenario utilizes the variables discussed previously which tepresent 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 /> Summa. •of Nitrate Mass Balance Anal sis. <br /> Result Acres Average Daily Effluent Concen- Leacbficld Deep Percolation of <br /> (Nc) * (A) Flow(Q) (Table l) tratiou(Nw) De tittifi- Rainfall(R) <br /> (mg/L-N) (gpd) (mg/L-N) cation (d) (Platt 9)(in.) <br /> ?A 5 560 45 25% 5.76 <br /> %axdm=contaminant level(MCL) for rutrate in drinking water is 10 rag/I.iv. <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 Hantzscbe and. <br /> Fennemote 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/J_-N. <br /> 4.0 DISCUSSION OF NITRATE LOADING RESULTS <br /> 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/.1,:N. 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 /> The well water test for nitrates indicateda,result of 21.7 mg/J.NO3 wbicb is well below the 1v4CL of <br /> 45-mg/L. It appears that the aquifer at which the well is drawing is not experienced elevated citrate <br /> concentration in ground water. <br /> 4.2 Methods of Mitigation <br /> No mitigation is proposed. <br /> 6 "004 <br />