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MOUND DESIGN WORKSHEET <br />(For Flows up to 1200 gpd) <br />A. FLOW <br />Estimated 73"0 gpd (seepages D-7 or I-3, 4, 5) <br />or measured gpd. arc 900 C-po <br />B'.SEPTIC TANK LIQUID VOLUMES <br />/1 So A /D 00 gallons (see pages C-3 or C-5) <br />/ZJ.9 ir,4ti v PNMIivG f, Aht <br />C.' SO11S (refer to site evaluation) <br />1. Depth to restricting layer = 2,2 inches <br />2. Depth of percolation tests = /6 inches <br />3. Percolation rate _ 13.7 mpi <br />4. Land slope I % <br />D. ROCK LAYER DIMENSIONS <br />I. Multiply flow rate by 0.83 to obtain required area of rock <br />layer: A x 0.83 = <br />0 D gpd x 0.83 sq. ft./gpd = 7S0 sq. ft, . <br />2. Select width of rock layer (10 feet or less) _ /0 ft. <br />3. Length of rock layer = area + width = <br />75-41 sq. ft. + 10 ft. = 7- . Oft. <br />E. ROCK VOLUME <br />1. Multiply rock area by rock depth to get cubic feet of rock; <br />7So sq. ft. x / ft. = 7So cu, ft. <br />2. Divide cu. ft. by 27 cue ft. /cu. yd. to get cubic yards; <br />7SO cu. ft. + 27 =.27.78 cu. yd. <br />3. Multiply cubic yards by 1.4 to get weight -of rock in tons; <br />27.78 cu. yd. x 1.4 ton/cu. yd. =3� tons. <br />r. AUbUX. FTION WIDTH <br />1. Percolation rate in top 12 inches of soil is /is 7 mpi <br />2. Select allowable soil loading rate from table on page E-16; <br />afE o.60. gpd/ft2 <br />3. Calculate adsorption width ratio by dividing rock layer <br />loading rate of 1.20 gpd/ft2 by allowable.soil loading rate; <br />1.20 gpd/ft2+0. 60 gpd/ft2 = 2 . o O <br />Check this value on page E-16. <br />4. Multiply adsorption width ratio by rock layer width to get <br />required adsorption width; <br />2, go x / 0 ft = 20. Oft <br />E-19 <br />D-7 <br />C-3 <br />.w lw. IAl1A GA/ACITIES. IN GALLONS <br />N i , op LIOYIo C"ACRt <br />mum r .14 Y.e•s, <br />tmemom LN*M OAIAel1. 6,09sI <br />v clause <br />is* <br />/ul <br />emle <br />lose <br />logo <br />some <br />lose <br />list <br />T. e. m s <br />veto <br />etoo <br />Rock Bed <br />•r•�.r.r rer.r r r r r r r r r <br />i.r•r.+•+.r.r.i.r•i.i•r•r•r•r <br />I•ti.I.� ti.ti. Idth SlUft. <br />I--,�3iI <br />•hh .r•f.I•Hh� I~rtirtir <br />e Lw8th <br />E-16 <br />WMM•e Aowomoo.•Ies OF •011 W.". lo—es <br />,- <br />Ah- <br />f-• <br />-- <br />l.N <br />!M <br />N <br />•". <br />eM <br />eel• <br />.N <br />.l ..e <br />!.N <br />•N <br />; N <br />;.N <br />• . N <br />•l .INsit•.N <br />•.N <br />e <br />•.I! <br />.o <br />•N I <br />I.•t <br />•,N <br />