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ONS�TC � <br /> SEwstia� Pr1111aIy SI� Job#� <br /> TREATM�NT <br /> PROfiRA/M ��" <br /> University of Minnesota Mound Design Worksheet <br /> Greaterthan 1%Siopes <br /> A FLOW <br /> Es6mated 900 gpd(see figure A-i) <br /> or measured x 1.5(safety factor)= 0 gpd <br /> B. SEPTIC TANK LIQUID VOLUMES <br /> Septic tank capacity 3000 gallais(see frgure G1) <br /> Number of tanks/compartments 0 <br /> Effluent Fifter (yes/no) yes <br /> C-1 Septic Tank Capacity in Gallons <br /> Number of Minimum Capacity with Capaaty with <br /> Bedro�ns Capacity Garb.Disp. Disp.and Lift <br /> 2 orless 750 1125 1500 <br /> 3 or 4 1000 1500 2000 <br /> 5�6 1500 2250 3000 <br /> 7,8 or 9 2000 3000 4000 <br /> C. SOILS(Site evaluafion data) <br /> 1. Depth to restricting layer= 1.8 feet <br /> 2. Depth of percolation tests= 12 inches <br /> 3. Texture loam <br /> 4. Soil Ioading rate(see Figure D-33) p.gp gpd/ft <br /> Percola6on rate 11 MPI <br /> 5. °�Land Slope 7.0 9�0 10°�6 upslope <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply average design flow(A)by 0.83 to obtain required area of rodc layer.ttem A x 0.83= <br /> 900 gpd x 0.83 ftlgpd= 750 ft <br /> 2. Detertnine rodc layer width =0.83 ft`/gpd x Linear Loading Rate(LLR)(see LLR chart) <br /> 0.83 ftZ/gpd x 12.00 = 10.0 ft <br /> LLR Chart <br /> Perk Rate LLR <br /> <120 MPI <=12 <br /> >=120 MPI <� <br /> 3. Length of rodc layer=area divided by width= <br /> 750.0 ft� / 10.0 feet= 75.0 ft <br /> E. ROCK VOLUME <br /> 1. Mul6ply rock area by rock depth to get cubic feet of rock <br /> 750.0 X 1.0 ft= 750.0 ft3 <br /> 2. Divide ft tiy 27 ft/yd3 to get cubic yards <br /> 750.0 ft3 / 27 = 27.8 yd3 <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons; <br /> 27.g yd3 X 1.4 toNyd3 = 38.9 tons <br /> Page 1 of 5 <br />