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Fof of Alkalinity Requirement for Nitrification rate-nitrogen loading calculations above are contingent upon the environmental factorsitrification to occur. These conditions include soil pore-space oxygen content, soil pH, electrical conductivity, organic matter, cation exchange capacity, and alkalinity. 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(NH;N) 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 concentration87 mg/L obtained from the three Church samples referenced in the Primary Report on Page would require: 87 mg/L NH4 N x 7.1 mg CaCO3=618 mg/L alkalinity. As noted in Table 11 of the Primary Report, the average alkalinity was 563 mg/L, which may be slightly 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 may be that nitrification will be inhibited if the Total Nitrogen concentration from the Multipurpose Building is similar to the three sampled Churches. Mounding Analysis Since the groundwater was determined to be 57.5 feet below existing grade in the 2003 drilling investigation, mounding potential should be nonexistent and inconsequential. Additionally, since a gravel stratum was encountered in the two backhoe test pits at eight feet below grade, this also would in all likelihood prevent the formation of the mound phenomenon under the disposal area. E. SURFACE WATER INFORMATION One drainage retention basin for Phase I is to be located 90 feet north-northeast of the future disposal area, with another basin 600 feet southeast of the disposal area. The 100%Reserve/ Replacement Disposal Area, is to be adjacent to the south of the Primary Disposal Area. The surface water retention pond for the complete development of the project will be at the northeast corner of the subject property. There should be no impact to impoundment water from the proposed filter bed due to the separation distances. Depending on the directional flow upper groundwater aquifers, which likely follows the terrain of the land surface,places the retention basin downgradient to the future filter bed. Regardless of the precise groundwater directional flow, percolating rainwater from the basin into the top aquifer mixing layer may create a dilution effect to the percolating septic system effluent. However,this can only be truly discerned with complicated groundwater monitoring and modeling. According to a scientific paper authored by Shaw and Turyk(See References), reduction of nitrate concentrations in groundwater can occur primarily through dispersion, or by percolating rainwater recharge. CliTData amfall vers s Evapotranspiration NL9§3.2 The(Primary Repo for this project discusses in detail, applicable climatic data since the original aste ter disposal esign was to take advantage of evapotranspiration. While the design criteria for the tipurpo Building expressed in this report is partially dependant upon evapotranspiration, t e ata in the Primary Report discusses its beneficial aspects. Page -8- Chesney Consulting