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MOUND DESIGN WORKSHEET <br /> (For Flows up to 1200 gpd) <br /> IA. FLOW Estimated Sewage Flows in Gallons per day <br /> Estimated I o o gpd Number type i type II Type III <br /> or measured x 1.5 = gpd. Beof <br /> ce s <br /> 2 300 225 180 6o% <br /> B. SEPTIC TANK LIQUID VOLUMES 4 6 0 33055 22.'56 atm <br /> " <br /> 5 750 450 294 i' <br /> 1'50,0 gallons 6 900 525 332 Tyre'. <br /> 7 1050 600 370 11 or <br /> 8 1200 675 408 in <br /> C. SOILS (refer to site evaluation) columns <br /> 1. Depth to restricting layer= a inches a• feet Capacities(in gallons) <br /> 2. Depth of percolation tests = I a inches Number of Minimum Liquid Liquid capacity with <br /> 4�Am Bedrooms Capacity garbage disposal <br /> 3. Texture <br /> Percolation rate 3. a mpi <br /> 2 or less 750 1125 <br /> 4. Land slope 6 % 7 50 u' 3 or 4 1000 1500 <br /> 5 or 6 1500 2250 <br /> 7,8 or 9 2000 3000 <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply flow rate by 0.83 to obtain required area of rock layer: A x 0.83 = <br /> 600 gpd x 0.83 sq. ft./gpd = s0 o sq. ft. • <br /> 2. Select width of rock layer (max 10' if<120 mpi max 5') = /0 ft. <br /> 3. Length of rock layer = area=width = ...;:.-.:.:,.,..4.-..,.....::::.,, • a�"nd .�:ddrtao:�prd„ep.A.,,a:o.. 00 <br /> ';.;,yr4� <br /> Sou 1:, <br /> .S ft. _ �� ft. = J�� ft a a� �x4,� ��a. � rtx xn ..Ru..Rx`�n n _ nv <br /> q a .kms . A'. aRb. _ <br /> Y.� r,.x-.r 4 vis arm.09 r, Q 4°r..r, S <br /> Width ,0 ft <br /> <120mpi <10' Length -Co ft <br /> E. ROCK VOLUME <br /> >120mpi <5' <br /> 1. Multiply rock area by rock depth to get cubic feet of rock; so, sq. ft. x ho 3- <br /> ft. = .s.) <br /> ft. = s.)5' cu. ft. <br /> 2. Divide cu. ft. by 27 cu. ft./cu. yd. to get cubic yards; <br /> Sds' cu. ft. =27= (9.,--1 cu. yd. <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons; /. 9 cu. yd. x 1.4 <br /> ton/cu. yd. = a2,:z,tons. <br /> ..F. ABSORPTION WIDTH Absorption Width Sizing Table <br /> 1. Percolation rate in top 12 inches of soil is 2. 'k.. mpi Percolatice Rate in Gallons Ratio of Absorption <br /> Texture (UAr+, Minutes per Inch Soil Texture per day per width to Rock <br /> (MPI) square foot Layer Width <br /> Faster than 0.1 Coarse Sand 1.20 1.00 <br /> 0.1 to S Sand 1.20 1.00 <br /> 2. Select allowable soil loading rate from table; 0.1 to 5 Fine Sand 0.60 2.00 <br /> � 6 to 15 Sandy Loam 0.79 1.52 <br /> • (o U g p�d/1 l-2 316 to 30 <br /> Loam 0.60 2.00 <br /> to 45 Sim 0.50 2.40 <br /> 46 to 60 Clay Loam 0.45 2.67 <br /> 60 to 120 Clay0.24 5.00 <br /> 3. Calculate adsorption width ratio by dividing rock layer Slower than 120 Clay 0.20 6.00 <br /> loading rate of 1.20 gpd/ft2 by allowable soil loading rate; <br /> 1.20 gpd/ft2+ •c'v gpd/ft2 = ' . <br /> 4. Multiply adsorption width ratio by rock layer width to get <br /> required adsorption width; <br /> a x /v ft= av ft <br />