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The details of the nitrate loading calculations are included in Plates 16 through 19. The results of the four calculations are presented in the following table. Table 5. Result of Nitrate Loading Calculations Variable Value Units Description Nc Long-term average concentration of percolating effluent, (Parcel 1) 0.3 mg/L-N Parcel 1 (No development, Plate 16) Nc Long-term average concentration of percolating effluent, (Parcel 2) 0.3 mg/L-N Parcel 2 (No development, Plate 17) Nc Long-term average concentration of percolating effluent, (Parcel 1) 0.5 mg/L-N Parcel 1 (Theoretical Future Houses, Plate 18) Nc Long-term average concentration of percolating effluent, (Parcel 2) 0.6 mg/L-N Parcel 2 (Theoretical Future Houses, Plate 19) Based on the method and assumptions described, maintaining zero development on each parcel would result in a buildup of nitrates in the aquifer up to 0.3 mg/L-N, equivalent to the measured rainwater concentration. Were two houses to be placed on each parcel, the maximum buildup of nitrates in the aquifer from the use of septic systems on the Site is predicted to be 0.5 mg/L-N for Parcel 1 and 0.6 mg/L-N for Parcel 2. This calculation assumes future houses which are not planned for the Site. The US EPA recommended MCL for nitrate in drinking water is 10 mg/L-N. In all four scenarios, the results of the nitrate loading calculation are well below maximum drinking water standard. Discussion of Nitrate Loading Results Total Nitrate Impact Based on the method and assumptions described, the results of the nitrate loading estimates indicate that impact to the ground water from no development or from the placement of two houses with up to eight bedrooms total on each parcel would be well below 10 mg/L-N. Based on the results of the calculations, no nitrate mitigation is recommended for any future primary and second unit dwellings on the Site up to eight bedrooms total per parcel. No construction is planned. LOGE 20-08 Page 13