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MOUND DESIGN WORKSHEET <br /> • (For Flows up to 1200 gpd) <br /> A. FLOW Estimated Sewage Flows in Gallons per day <br /> (xpd) <br /> Estimated rioC>o gpd Number Type TnXH TypeOf <br /> I1ve <br /> or measured x 1.5 = gpd. a [V <br /> 2 300 225 180 60 <br /> Of the <br /> B. SEPTIC TANK LIQUID VOLUMES 4 6 0 33055 2256 abbe <br /> I SUU gallons 6 90 4525 33i p <br /> 7 1050 600 370 Type- <br /> u or <br /> 8 1200 675 408 W <br /> C. SOILS (refer to site evaluation) cohImn.* <br /> 1. Depth to restricting layer= 3o inches a• s feet Septic Masik C°p""``s(in gallow) <br /> 2. Depth of percolation tests = /a' inches Number of Minimum Liquid Liquid capacity with <br /> 3. Texture SAM Percolation rate 3 mpi Bedrooms capacity garbage disposal <br /> 2 or less 750 1125 <br /> 4. Land slope 2 - 6 % 3 or 4 1000 1500 <br /> 5 or 6 1500 2250 <br /> 7,8 or 9 2000 3000 <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply flow rate by 0.83 to obtain required area of rock layer: A x 0.83 = <br /> 6 w gpd x 0.83 sq. ft./gpd = Sh-o sq. ft. <br /> 2. Select width of rock layer(max 10' if<120 mpi max 5')'= /0 ft. <br /> 3. Length of rock layer= area+width= ... a <br /> Sov , sq. ft. + zo ft. ft. <br /> Width 1 U ft <br /> <120mpi <10' LenSth__,ro-ft <br /> E. ROCK VOLUME >120mpi <5' <br /> 1. Multiply rock area by rock depth to get cubic feet of rock;. tv sq. ft. x i.o <br /> ft. = sat cu. ft. <br /> 2. Divide cu. ft. by 27 cu. ft./cu. yd. to get cubic yards; <br /> S'�s cu. ft. +27= 19, tr cu. yd. <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons;J1.fcu. yd. x 1.4 <br /> ton/cu.yd. = ;1-3 tons. <br /> F. ABSORPTION WIDTH Absorption width sizing Table <br /> 1. Percolation rate in top 12 inches of soil is.mpi FercoladaRaft in Gallons RatioofAbsorpdon <br /> �-0Minutes per Inch Soil Texture per day per width to Rock <br /> Texture �4M (MPI) square foot Layer Width <br /> Faster than Q.1 coarse sand I.20 1.00 <br /> 0.1 to 5 Sand 1.201.00 <br /> 2. Select allowable soil loading rate from table; 0.1 tos Flne Sand 0.60 2.00 <br /> gpd/ft' 6t is saLons 0.79 1.52 <br /> v 16 to 30 Lam 0.60 2.00 <br /> �r 31 to 45 silt Loam 0.50 2.40 <br /> 46 to 60Gay L am 0.45 2.67 <br /> 60 to 120 Gay 0.24 5.00 <br /> 3. Calculate adsorption width ratio by dividing rock layer slower d-120 Gay 0.20 6.00 <br /> loading rate of 1.20 gpd/ft2 by allowable soil loading rate; <br /> 1.20 gpd/ftz+ gpd/ft2= a <br /> 4. Multiply adsorption width ratio by rock layer width to get <br /> required adsorption width; <br /> _x_ 8 ft=_eft <br />