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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) <br /> Estimated 1,00 gpd Number of Type I type II Type III Type 1V <br /> or measured - x 1.5 = - gpd. Bedrooms <br /> 2 300 225 180 ars <br /> 3 450 300 218 et <br /> B. SEPTIC TANK LIQUID VOLUMES 4ec <br /> 600 375 256 <br /> 5 750 450 294 u <br /> "a..- /000 gallons 6 900 525 332 d10 <br /> 7 1050 600 370 a:- <br /> 8 1200 675 408 <br /> C. SOILS (refer to site evaluation) ® <br /> t1 Numb,f5 L <br /> 1. Depth to restricting layer = C inches sem , ,, <br /> 2. Depth of percolation tests = ' )x1 inches (pass) ` '' <br /> 3. Percolation rate /4-18 mpi 2«less <br /> 750 1.125 <br /> 3«4 <br /> 1.000 1.500 <br /> 4. Land slope y % s«61.500 2.250 <br /> 7«8 2.000 3.000 <br /> ova 9 See fig.C-6 (x 1.5) <br /> D. ROCK LAYER DIIv1ENSIONS <br /> 1. Multiply flow rate by 0.83 to obtain required area of rock <br /> layer:A x 0.83 = <br /> (£o(9c) gpd x 0.83 sq. ft./gpd = t. g sq. ft.two silt <br /> 2. Select width of rock layer (10 feet or less) = /o ft. <br /> 3. Length of rock layer = area_width = Rock Bed <br /> _s'i 1 sq. ft.i I o ft. = 5 S ft. .....................•............ <br /> �•1•r•r•!•1.1� t•t t•f•t•r•t•!•!•1 <br /> .......•.....tS...;............•tiidth 5.10 ft. <br /> r_1.._!_11 f1,l_1v111111111 <br /> E. ROCK VOLUME F--- Length .4 • <br /> 1. Multiply rock area by rock depth to get cubic feet of rock; <br /> S41 sq. ft. x/.o s'ft. = 5114 cu.ft. <br /> 2. Divide cu. ft.by 27 cu. ft./cu. yd. to get cubic yards; <br /> "5'74cu.ft. =27= a ) cu. yd. <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons; <br /> P. I. cu. yd. x 1.4 ton/cu. yd. = tons. <br /> F. ADSORPTION WIDTH 1..`-A`4 Lola rel Absorption Width Siring Table <br /> 1. Percolation rate in top 12 inches of soil is I L- ' mpi Percolation Rate CaNns RAO d <br /> Minutes°nixJ in Ci, Soil Texture 4.q „ <br /> tan asa er <br /> 2. Select allowable soil loading rate from table; Faster than 0.1 Coarse Sand 1.20 1.00 <br /> y < gpd/ft'- 0.1 toy Sand 1.20 1.00 <br /> 0.1 to S Fine Sande` 0.60 2.00 <br /> 6 to 15 Sandy Loam 0.79 132 <br /> 163. Calculate adsorption width ratio bydividingrock layer 31 to 30 loam 0.60 2.00 <br /> rp }' 31 to 45 Silt Loam 0.50 2.40 <br /> loading rate of 1.20 gpd/ft2 by allowable soil loading rate; 46 to 60 Clay Loam 0.45 2 .67 <br /> 61 tO 120 Clay <br /> 1.20 gpd/ft2i .14S gpd/ft2= 2 . 1.7 . Slower than 120 _ Clay -- - <br /> ••Soil having 509E 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 /> 21.,7 x /o ft= a1,7 ft <br />