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22� CONCLUSIONS There are three significant issues with this project that require resolving provision conflict: Issue 1. The existing onsite well must be destroyed under EHD permit and a new must be installed in the extreme northwest corner of the subject property. Issue 2. The nitrate loading criteria were determined to be under the Maximum Contaminant Level (MCL) of 10 mg/L. Soil analytical test results indicate denitrification occurring at the deeper soil depths. Therefore, it can be assumed that nitrogen in percolating effluent that nitrifies to nitrate, will undergo denitrification. Nitrate well analysis in five water wells surrounding the property, as indicated on the EHD Nitrate - Land Use Data Map in Appendix E, indicate two wells have nitrate concentrations between 5.1 and 10.0 Mg/L and three wells have concentrations of 0.1 and 5.0 Mg/L nitrate. Two wells downgradient to the subject property possess concentrations exceeding 10.0 Mg/L nitrate; however, given the significant amount of upgradient agricultural production land and a medium density of OWTS,this would be expected. To mitigate nitrate loading from the proposed OWTS,the design utilizes a double-depth filter bed, an 8 ft sump and a retaining partition separating the filter bed and sump. The partition acts as a dam retaining effluent within the filter bed. When the filter bed fails,the effluent will flow over the partition and into the sump. The retaining partition is protected from erosion by an impermeable geotextile fabric. The filter bed gives the smallest footprint for effluent disposal needed since the property area is highly constrained. By not specifying seepage pits to be installed,the filter bed and sump structures maintain the maximum distance between the floors of these structures and the groundwater depth that exceeds 100 ft. Issue 3. As referenced,the new onsite well is to be installed in the extreme NWC of the property. This location places the new well 50 ft to the west of the proposed 100%replacement area, as illustrated on the Design Plans. The domestic well located adjacent to the north of the subject property at 1999 Patterson appears to be in the back of the property, as highlighted in the EHD files found in Appendix G, but was never located. These two wells (the new well to be drilled and the well at 1999 Patterson) will be upgradient to the proposed OWTS, based on the groundwater directional flow data on Page 2. The well located south of the subject property at 1867 Patterson is approximately 20 ft from the property line. This well will be approximately 50 ft from the proposed OWTS and will be considered cross gradient to the proposed OWTS also as referenced by the groundwater directional data on Page 2. Page -6- Chesney Engineering, Inc.