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F e nitrogen loading rates anticipated from the St. Bernard's Church Complex with the subject property in agricultural production, we find that previous crops that may have the subject property have required between 175 and 255 pounds of nitrogen per acre m the Western Fertilizer Handbook: grain sorghum requires 250 lbs N, safflower ar beets 255 lbs N,beans 175 lbs N,tomatoes 180 lbs N). Using an estimate of 215 lbs of N/acre/yr for crop uptake with 33%nitrate-nitrogen leaching(Ref. 1)past the root zone= 71 lbs N/ac/yr potentially impacting the underlying groundwater from historical agricultural nitrogen fertilizer inputs. These inputs exceed the average calculated yearly nitrate-nitrogen loading anticipated from the Church Complex by 21% (71 lbs N/ac/yr vs. 56 lbs N/ac/yr). Comparing the nitrogen loading rates anticipated from the St. Bernard's Church Complex with the subject property if it were to be built-out as a residential subdivision on septic systems: Assuming the per capita nitrogen output is 6 kg N/person/year and total output percolates to groundwater= 13.2 lbs N/person/year x 3 people/house x 2 houses/ac = 79.2 lbs N/ac/yr. This is a 29%increase over the yearly nitrate-nitrogen loading anticipated from the Church Complex (79 lbs N/ac/yr vs. 56 lbs N/ac/yr). Calculation of Alkalinity Requirement for Nitrification All of the nitrate-nitrogen loading calculations above are contingent upon the environmental factors required for nitrification to occur. These conditions include soil pore-space oxygen content, soil temperature, pH, electrical conductivity, organic matter, cation exchange capacity, and alkalinity. Alkalinity in wastewater effluent is derived from the domestic water supply in addition to the introduction of wastes. As referenced,nitrification consumes approximately 7.1 mg of alkalinity for every mg of ammonia-nitrogen (NH4-I) oxidized. Although the effluent sampled from the three Churches all exhibited high alkalinity, domestic well water from deeper aquifers generally has a much lower alkalinity than shallower groundwater. Nitrification of the average Total Nitrogen concentration of 87 mg/L obtained from the three Church samples would require: 87 mg/L NH4 N x 7.1 mg CaCO3 =618 mg/L alkalinity. As noted in Table 11,the average alkalinity was 563 mg/L, which is insufficient. Comparing the alkalinity of the water table groundwater under the future disposal field at 293 mg/L and assuming the future domestic well water will have an alkalinity of approximately 120 mg/L, it maybe that nitrification will be inhibited if the Total Nitrogen concentration from the St. Bernard's Church Complex is similar to the three sampled Churches. 6. PRELIMINARY WASTEWATER DISPOSAL SYSTEM DESIGN AND OPERATIONAL CRITERIA The following information describes the preliminary details of the wastewater disposal system for the St. Bernard's Church and Multipurpose Building. Since the entire project is in the initial phases of planning, several facets of the project are subject to change, which in turn may cause changes to the wastewater disposal system. As the project continues and construction details are finalized, wastewater disposal design plans and an operational report will be submitted to St. Bernard's LChurch and EHD. Page -19- Chesney Consulting