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r. Hughes Hardwoods J <br /> May 5,2003 <br /> Page 8 <br /> 6.4 Nitrate Loading Balance <br /> A nitrate loading balance was performed to estimate the long term impact of using a standard <br /> type septic system on the property. All the previously described assumptions were unitized in the <br /> Hantzshe and Finnemore equation. The nitrate loading calculation is shown on Plate 9. The <br /> following is a summary of the nitrate loading balance. <br /> ■- Table 6. <br /> Summary of Nitrate Mass Balance Analysis. <br /> Scenario Result Acres Average Effluent Leachfield Deep Percolation <br /> (Nc)* (A) Daily Concen- Denitrifi- of Rainfall(R) <br /> Flow(Q) tration cation(d) (Plate 8) <br /> (Table 5) (Nw) <br /> Standard Septic 8.6 mg/L-N 2.5 149 gpd 75 mg/L-N 25% 5.01 in <br /> _ <br /> System Plate 9) <br /> * Maximum contaminate level(MCL)for Nitrate in drinking water is 10 mg/L-N. <br /> _ <br /> 7.0 DISCUSSION AND RECOMMENDATIONS <br /> _ Our office believes the site is suitable for development utilizing a standard type septic system <br /> with shallow leach lines and seepage pits. A satisfactory percolation rate was achieved from the <br /> "deep"percolation test conducted within the proposed septic system disposal field. According / <br /> the Sewage Standards and Percolation Test Procedures of the EHD, a septic system with shallow <br /> leach lines and 25-foot deep seepage pits should be utilized due to the presence of clayey surface <br /> ;Ottsoils. <br /> Based on the methodology, assumptions and limitations of the Hantzshe &Fi <br /> we believe the proposed project will not cause a long term buildup ofttitrates above 10 <br /> in the ground water. The proposed low average daily flow,the presence of fine grained soils, and <br /> the separation between ground water and seepage pits should provide some additional measure of <br /> _ <br /> protection. <br /> 8.0 LIMITATIONS <br /> The conclusions of this report are based on the information provided regarding the existing and <br /> proposed development, the use of the subject property, and the site conditions as they existed at <br /> _ the time we excavated our test hole and performed the percolation test. It was assumed that the <br /> test hole and percolation test results are representative of the subsurface conditions in the general <br /> area. <br /> pE RSOy <br /> Z � <br /> O � <br /> 7,qS O G♦ <br /> r <br />