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MOUND DESIGN WORKSHEET <br /> (For Flows up to 1200 gpd) <br /> A. FLOW Estimated Sewage Flow in Gallons per Day(gpd) I <br /> Estimated 1,o 0 gpd Number <br /> of Type I Type II Type III Type IV <br /> or measured - x 1.5 = ` gpd. Bedrooms <br /> 2 300 225 180 60% <br /> 3 450 300 218 ' <br /> B. SEPTIC TANK LIQUID VOLUMES • 4 600 375 256 .,,,v <br /> 5 750 450 294 is <br /> oZ-/ODD gallons 6 900 525 332 <br /> 7 1050 600 370 or% <br /> `' a`/ 8 120µm � <br /> 675 408 <br /> C. SOILS(refer to site evaluation) ` Number T� � <br /> 1. Depth to restricting layer= 1 inches Bed°of <br /> 2. Depth of percolation tests = ) a inches `°""' (Whoa) <br /> 3. Percolation rate i t. (.• mpi 230<'4` 1.000 1.s o <br /> 4. Land slope a % 7 or 8 2.000 2.250 000 <br /> over 9 See fig.C-6 (z 1.5) <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply flow rate by 0.83 to obtain required area of rock <br /> layer:A x 0.83 = <br /> oo. gpd x 0.83 sq.ft./gpd = 1-1,02sq. ft.-1-►oho-.S V) <br /> 2. Select width of rock layer(10 feet or less) = /0 ft. <br /> 3. Length of rock layer = area s width= Rock Bed <br /> S4'7 sq. ft.÷ /o ft. = 5. ft. <br /> ti•ti•ti.ti•,.•�.,.•1•ti•ti•,,.,,•,.•�•ti•,.ti <br /> r•r•f•r•r•r•f•r•r•r ttte:r•:4•Z: .:width _<10 ft. <br /> \•ti•ti•tiKK•ti•tiKKK•1,•ti•ti•ti•ti•ti <br /> rzf~r20,31.ott24trozo:+1.01.0.te:#:0:011 I <br /> E. ROCK VOLUME �- Length <br /> 1. Multiply rock area by rock depth to get cubic feet of rock; <br /> s`-t') sq.ft. x /.oaf ft. = .S-7,4 cu.ft. <br /> 2. Divide cu.ft.by 27 cu. ft./cu. yd. to get cubic yards; <br /> Soy cu.ft. ÷27= a I cu. yd. <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons; <br /> a) cu.yd.x 1.4 ton/cu. yd. = tons. <br /> F. ADSORPTION WIDTH 41r4-`e )..01 0,1.1 Absorption Width Siring Table <br /> 1. Percolation rate in top 12 inches of soil is 1). �,mpi percolation nape cows Raded <br /> Minutes pe inch Soil Texture <br /> lar sr: m <br /> 2. Select allowable soil loading rate from table; Faster than 0.1 Coarse Sand 1.20 1.00 <br /> d <br /> d/ftz 0.1 toy Sand 1.20 1.00 <br /> 0.1 to 5 Fine Sand" 0.60 2.00 <br /> 6 to 15 Sandy Loam 0.79 1.52 <br /> 3. Calculate adsorption width ratio by dividing rock layer 16 to 30 Silt Loam 0.60am 2.40 <br /> loading rate of 1.20 gpd/ft2 by allowable soil loading rate; 46 to 60 Cla Loam 0.45 2.67 <br /> 61 120 <br /> 1.20 gpd/ft21 ,y gpd/ft2= a.Vr7 . SlowerOthan 120 Clay 0.24 5_00 <br /> ••Sod having 50%or more of fine or very fine sand <br /> 4. Multiply adsorption width ratio by rock layer width to get <br /> required adsorption width; <br /> x lo ft= at-e) ft <br />