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Cr �VLalues and Assumptions <br /> 900 gpd X=258d/ (From water Provision Declaration)=232,200 gals=total W W/yr=31,043 cu ft = 0.307in/yr <br /> 27.9 Ac x 43,560 sq ft/Ac x(1 ft/12 in.) <br /> Nw =62 mg N/L <br /> d = Assume 20% due to the fine-grained soil at the soil-effluent interface. <br /> R = 3.6 in/yr. <br /> Nb= Assumed to be 0.1 ppm NO,-N <br /> 0.307 in/yr(62 mg N/L) 0 - 0.20)+(3.6 in/yr x 0.1 my,/L) <br /> Nr = (0.307 in/yr+3.6 in/yr) <br /> Nr = 4.0 ppm as nitrate-nitrogen (NO3 N)or 17.8 ppm as nitrate(NO3) <br /> The calculated nitrate loading concentration in the recharge effluent from all nitrogen sources <br /> within the subject APN will to be 60%under the Maximum Contaminant Level limit for nitrate in <br /> drinking water, and is 2.5 ppm under the existing nitrate concentration in the on-site well water. <br /> IV. WASTEWATER DISPOSAL SYSTEM: <br /> OPERATIONAL PARAMETERS <br /> Septic Tank Sizing <br /> Influent from the proposed four Unisex Restrooms will gravity flow into a 2,000 gallon septic tank. <br /> The tank should be pumped on a prescribed interval basis depending on direct observations; e.g., <br /> every six months to every three years, depending on sludge/scum accumulation to be determined <br /> by a septic system contractor. <br /> Septic Tank Hydraulic Detention Time for the Septic Tank <br /> Detention Time=2 000ag 1 septic tank capacity x 0.70(30%volume lost to sludge/scum accumulation) <br /> 1.5 (Peaking Factor)x 900 gals/day ADF <br /> Detention Time = 1.0 days. The typically acceptable detention time is 1.0 days. <br /> Therefore, a 2,000 gallon septic tank is appropriate. <br /> Primary and 100% Replacement Filter Bed Areas for the proposed Four Unisex Restrooms: <br /> The filter bed area is calculated by the procedure described in EHD Document 42-01-004 <br /> Calculation Requirements for Commercial Septic Systems: <br /> Base Tank Capacity (BTC) = 1,200 gals <br /> Lineal Feet of Leachline (LFLL) = 1,200 BTC + 900 ADF from six Unisex Restrooms x 0.200 Soil <br /> Factor based on a sandy loam soil = 420 LFLL <br /> Filter Bed Area=420 LFLL x 3 (Sandy Loam Soil Factor)= 1,260 square ft, or 36 ft square. <br /> Sheet 2 of 26 from JToste Engineering illustrates the orientation of the proposed OWTS. <br /> However, the following changes are noted: <br /> 7 <br /> Chesney Consulting <br />