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May 9, 2006 <br /> NOA Project Number:E05144B <br /> Page 2 <br /> Table 2. <br /> Weighted Average of Residential / Commerical <br /> Total Nitrogen Concentration <br /> 45 mg/L-N x 420 gpd= 18,900 mg/L-gal <br /> PS Xmg/L-N x 128 gpd= 10,880 mg/L-gal <br /> 528 gpd 29,780 mg/L-gal <br /> 29,780 m /L- al/ 528 =56.4 m /L-N <br /> Nitrate Loading Scenario <br /> This nitrate loading scenario was completed in order to estimate the impact from the proposed <br /> project using the total nitrogen concentration value the EHD has requested. The scenario utilizes <br /> the variables discussed previously which represent the estimated conditions and uses associated with <br /> this project. The following table presents a summary of the nitrate loading calculation for the parcel. <br /> Table 3. <br /> Summary of Nitrate Mass Balance Analysis. <br /> Parcel Result Acres Average Daily Effluent Leachfield Deep <br /> (Nc) * (A) Flow(Q) Concen- Denitrifi- Percolation of <br /> (mg/L-N) (Table 3) tration(Nw) cation(d) Rainfall(R) <br /> (gpd) (mg/L-N) (Plate 9) (in.) <br /> 1 6.0 45 548 56.4 20% 1.27 <br /> * Maximum contaminant level(MCL) for nitrate in drinking water is 10 mg/L-N. <br /> Impact of Nitrate Loading to Nearby Water Sources <br /> Based on the method and assumptions described,in addition to the geologic setting,we do not <br /> believe the proposed project will cause a build up of nitrate in the ground water above 10 mg/L-N <br /> over the long term. Since the Site is relatively flat,we do not foresee percolating effluent affecting <br /> any surface water resources. <br /> DISCUSSION OF NITRATE LOADING RESULTS <br /> Total Nitrate Impact <br /> Based on the method and assumptions described, the result of the nitrate loading balance indicates <br /> that the proposed development on the proposed parcels should not cause a build up of nitrate in the <br /> ground water above 10 mg/L-N over the long term. <br />