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MOUND DESIGN WORKSHEET <br />(For Flows up to 1200 gpd) <br />A. FLOW <br />Estimated (,oyo gpd (seepages D-7 or I-3, 4, 5) <br />or measured gpd x 1.5 = <br />B. SEPTIC TANK LIQUID VOLUMES <br />gallons (see pages C-3 or C-5) <br />C. SOILS (refer to site evaluation) <br />1. Depth to restricting layer = 2"I inches <br />2. Depth of percolation tests = r Z inches <br />3. Percolation rate 1 o mpi <br />4. Land slope S % <br />D. ROCK LAYER DIMENSIONS <br />1. Multiply flow rate by 0.83 to obtain required area of rock <br />layer: Daily Flow x /on = <br />&;iJ gpd x 0.83 sq. ft./gpd = -'o sq. ft. <br />2. Select width of rock laver (10 feet or less) = /G ft. <br />3. Length of rock layer = Area = Width = <br />Seo sq. ft. + /o ft. = ,5(D ft. <br />E. ROCK VOLUME <br />1. Multiply rock area by rock depth to get cubic feet of rock; <br />sq. ft. x / ft. = -42y cu. ft. <br />2. Divide cu. ft. by 27 cu. ft./cu. yd. to get cubic yards; <br />cu. ft. + 27 = -/5-15'cu. yd. <br />3. Multiply cubic yards by 1.4 to get weight of rock in tons; <br />2. S cu. yd. x 1.4 ton/cu. yd. = Z-� tons. <br />F. ADSORPTION WIDTH <br />1. Percolation rate in top 12 inches of soil is LO mpi <br />2. Select allowable soil loading rate from table on page E-; <br />0'"7! gpd / f t2 <br />3. Calculate adsorption width ratio by dividing rock layer <br />loading rate of 1.20 gpd/ft' by allowable soil loading rate; <br />1.20 gpd/ft2+ 0,79 gpd/ft2= /.G2 <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 />/,,52- x / ft = /S.2 ft <br />Estimated Sewage Flows in Galluns per day <br />Qpd) <br />um ber <br />fiedr f <br />Type I <br />Type Il <br />Type lit <br />Type <br />2 <br />300 <br />225 <br />180 <br />3 <br />450 <br />300 <br />218 <br />6" <br />4 <br />600 <br />375 <br />256 <br />°f A. <br />5 <br />750 <br />450 <br />294 <br />rv<. <br />6 <br />900 <br />525 <br />332 <br />�r•1• <br />7 <br />1050 <br />6W <br />370 <br />m <br />8 <br />1200 <br />675 <br />dog 1 <br />cd- <br />Scp.c T..k Capcil" i. aad-. <br />N-bv of <br />%fi. u n t.ig..d <br />I..qud c.pac.ty voa <br />11.dr.nm. <br />Cray <br />area. d�poaal <br />2 a le.. <br />750 <br />1125 <br />5 a. • <br />1000 <br />150o <br />4.6 <br />1500 <br />2250 <br />7.1 or 9 <br />20M <br />3000 <br />.19 9 <br />...... <br />Rock Bed <br />• {.� • ti.ti.�.., . ti.ti.t.ti.ti.�. Midth S10 ft. <br />• Length ---i <br />Absorption Width Sling Table <br />P01010d a Raw <br />is Min.ttltt per <br />Inch ("r I <br />Soil Teatafe <br />Gallon. <br />per day per <br />,gore root <br />RYb of <br />Ahaa 01- width <br />to Rock Dyer <br />Wdlh <br />Parr 6" 0.1 • <br />caarac Sand <br />a I to 5 <br />sad <br />1.20 <br />1.00 <br />0.1 IDS •• <br />Piss Sand •• <br />0.60 <br />2A0 <br />6w15 <br />Smdy ts <br />0. <br />2 <br />16 to 30 <br />Loom <br />o <br />2.W <br />31 io 45 <br />Sik Lam <br />0.50 <br />L40 <br />46,060 <br />Clay Lars <br />0.45 <br />167 <br />60 to 120 <br />CLy <br />0.24 <br />5.U0 <br />S101111e►thrr <br />clay <br />- <br />- <br />120 <br />