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To minimize wastewater flows originating from the Mission, "low-flow" sinks and toilets should be installed in the restrooms. Sinks should have spring-loaded fixtures to prevent accidental overuse. If required by the Environmental Health Department, the diversion box (D-box) may have to installed with a manually operated valve to "rest" sections of the leachfield. It is assumed that there are no future expansion plans of the new Sant Nirankari Mission. If the possibility exists for expansion or the addition of kitchen facilities, the entire operation and design of the septic system must be reviewed and may have to be revised. VI. NITRATE LOADING To calculate the nitrate loading for the proposed project, it is important that accurate wastewater flow volumes be projected as best they can. The initial flow volume for the Mission has been established at 210 seats and 5 gals/person/Sunday. This is similar to a housing subdivision or industrial/commercial facility where the maximum flow can be determined initially and there is usually not much deviation from this initial flow volume. As sewage enters septic tanks, approximately 25% to 33% is part of protein, with the remaining portion as urea. In the septic tank and the soil environment, ammonia from urea and protein decomposition, combine with water to form the ammonium ion, the precursor to nitrate. Aerobic bacteria oxidize ammonium to nitrate usually within two to five feet of unsaturated (aerobic) soil. This is called nitrification. Virtually complete nitrification of ammonium nitrogen occurs in the unsaturated zone in well-aerated soils under leachfields or mound systems. The per capita ingestion and excretion of nitrogen can be considered reasonably constant with minor variations. Although there are several estimates of nitrogen inflows based upon per capita intake of total nitrogen per day, a conservative estimate is 17 grams N/capita/day. Concerning outflows, most literature evaluates nitrogen discharged from septic systems in concentration units of mg N/L (milligrams of nitrogen per liter of effluent). There are several estimates of nitrogen effluent concentrations, however, the conservative average is generally regarded as 62 mg N/L. If a projected maximum wastewater flow of 1,050 gallons is used, the following calculations indicate the potential nitrate loading per year: 1050 gallons/Sunday= 3,975 L/Sunday X 62 mg N/L= 0.246 kg N/Sunday X 52 Sundays/year= 12.8 kg N/yr or 28.2 lbs. N/yr. 6 Vaffey Aq 2csearch