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MOUND DESIGN WORKSHEET <br /> (For Flows up to 1200 gpd) <br /> ' <br /> A. FLOW Estimated Sewage Flow in Gallons per Day(gpd) <br /> 1 <br /> Estimated ?SD gpd Number <br /> fType <br /> or measured x 1.5 = gpd. Bedrooms �YPe 1 II Type III Type IV <br /> 2 300 225 180 60% <br /> 3 450 300 218 of <br /> B. SEPTIC TANK LIQUID VOLUMES 4 600375 256 .� <br /> 5 750 450 294 N <br /> i- )a J o 40 1-100 O gallons 6 900 525 332 'n <br /> 7 1050 600 370 ��• <br /> if 8 1200 675 408 <br /> C. SOILS (refer to site evaluation) u ss l y <br /> Number .m..srwZrk p iyw <br /> 1. Depth to restricting layer = 19 a. inches of Bedrooms . <br /> 2. Depth of percolation tests = 1 D. inches `p°m'' `pliant) <br /> 3. Percolation rate l o,$ mpi 2less <br /> 3 750rl4 <br /> 1.000 1.5 0 <br /> 4. Land slope y % s or 6 <br /> 1.500 2.250 <br /> 7 or 8 2.0003,000 <br /> over 9 See fig.C-6 (x 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 /> '' <br /> 'SO gpd x 0.83 sq. ft./gpd = Lark sq. ft.+)v`'?0=G.g1 <br /> 2. Select width of rock layer (10 feet or less) = /0 ft. <br /> 3. Length of rock layer = area-width = Rock Bed <br /> tg cd LI sq. ft.÷ 10 ft. = <br /> (a ft. ati-=-a•bi..._..b_•bla b�bb��..bia_a.b_a.bb%rb %ib ."1tititiftitibli ti. <br /> rti%tivv.v.titiitiititii{itiititiitititw <br /> idth <_10 ft. <br /> . • •l•l•t•a••a••r•a••lVY•r•r•l•r•f•1 <br /> 1•b•:::;:t b•b•b•b•b•b•b•b•b•b•b•b• <br /> 1_f.'r:l_f_f:f:r:f1.0:0,01....:.....t.,:d.„?., <br /> E. ROCK VOLUME I Length 1 f <br /> 1. Multiply rock area by rock depth to get cubic feet of rock; <br /> (.,u y sq. ft. x /.os ft. _')i c cu. ft. <br /> 2. Divide cu.ft.by 27 cu. ft./cu. yd. to get cubic yards; <br /> '))4' cu. ft. y 27= a') cu. yd. <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons; <br /> 2.7 cu. yd. x 1.4 ton/cu. yd. = 3 B' tons. <br /> F. ADSORPTION WIDTH �l-A 1..0A"WI absorption Width siring Table <br /> 1. Percolation rate in top 12 inches of soil is mpi Percolation Rate Callan. Ratio a/ <br /> Minutes per inch Soil Texture a t., o?kit`m <br /> (mpi) feet ab:=1 <br /> 2. Select allowable soil loading rate from table; Faster than 0.1 Coarse Sand 1.20 1.00 <br /> 0.1 to 5 Sand 1.20 1.00 <br /> pis gpd/ft2 0.1 toy Fine Sand'"` 0.60 2.00 <br /> 6 to 15 Sandy Loam 0.79 1.52 <br /> 16 <br /> 3. Calculate adsorption width ratio by dividing rock layer 31 to 30 Loam 0.60 2.00 <br /> 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 t0 120 Clay 0.24 5.00 <br /> 1.20 gpd/ft24- '`4•• gpd/ft2= a-(o') . Slower than 120 Clay - - <br /> -.Soil 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 /> �_.1,') x )O ft=a(,•r) ft <br />