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MOUND DESIGN WORK SHEET (For Flows up <br />to 1200 <br />gpd) <br />Lwdina Rata <br />Gallo! <br />Per dsypar <br />Absorption <br />RaUo <br />A. Average Design FLOW <br />ramsand <br />htadlum Sand <br />InunY Sand <br />1.20 <br />079 <br />1.00 <br />1 So <br />1o <br />,A -l: Estimated Sewage Flows In Gallons per Day <br />Estimated 14 S 0 gpd (see figure A-1) <br />number o <br />bedrooms Clan I Clan 11 Class III <br />Class IV <br />or measured x 1.5 (safety factor) = gpd <br />2 <br />300 225 <br />180 <br />60% <br />Silty say <br />SaM ary <br />3 <br />450 300 <br />218 <br />of the <br />B. SEPTIC TANK Ca <br />Capacity <br />p t y <br />4 <br />600 375 <br />256 <br />values <br />5 <br />750 450 <br />294 <br />In the <br />6 <br />900 525 <br />332 <br />Class 1, <br />a - /000 gallons (see figure C-1) <br />7 <br />1050 600 <br />370 <br />11, or iii <br />I - ISoo -auati y}g,�y(,�y_ y+,us� <br />8 <br />1200 675 <br />1 408 1 <br />columns. <br />C. SOILS (refer to site evaluation) <br />011 Se ilc @ak Ca adties flil <br />alions <br />r i t <br />1. Depth to restricting layer = /��, feet <br />Numbuof Minimum liquid <br />Bedrooms opacity <br />Liquidcapacity with <br />subaso disposal <br />th <br />wrthdicapacty <br />2. Depth of percolation tests = /• o feet <br />iaslae <br />3. Texture Lt,{ tail. n <br />2orless 750 <br />7or4 1000 <br />nu <br />1500 <br />1500 <br />Percolation rate 5.2 mpi <br />7, or 9 2W 300 <br />3°p°° <br />30M <br />4S <br />4. Soil loading rate .gpd/sgft (see figure D-33) <br />5. Percent land slope Mi <br />D. ROCK LAYER DIMENSIONS <br />011 <br />3. <br />Multi ply average design flow (A) by 0.83 to obtain required crock layer area. <br />L4 <br />0 gpd x 0.83 sgft/gpd =, U 3 sgft-wo*o gOcP <br />Determine rock layer width = 0.83 sqft/gpd x linear Loading Rate <br />0.83 sqft/gpd x tZ _gpd/sqft = )0 ft <br />Length of rock layer = area + width = <br />1,0 sgft (D1) + Jo,_ ft (D2) = u 1 ft <br />E. ROCK VOLUME <br />1. <br />2. <br />3. <br />(LLR <br />Mound LLR <br />< 120 MPI <12 <br />> 1,20 MPI < 6 <br />Multiply rock area (Dl) by rock depth of 1 ft to get cubic feet of rock <br />4) 0 sgft x 1 ft = 910 cuft <br />Divide cuft by 27 cult/cuyd to get cubic yards <br />4) 0 cult + 27 cuyd/cult = ) S' cuyd <br />Multiply cubic yards by 1.4 to get weight of rock in tons <br />—ice cuyd x 1.4 ton/cuyd = - ;Q_ tons <br />SEWAGE ABSORPTION WIDTH <br />ption width equals absorption ratio (See Figure D-33) <br />rock layer width (D2) <br />a c� x Jct ft = a� ft <br />D-33: Absorption Width Sizing Table <br />Per lattan Rate <br />In MI�per <br />1 <br />soil Texnus <br />Lwdina Rata <br />Gallo! <br />Per dsypar <br />Absorption <br />RaUo <br />Faster than <br />ramsand <br />htadlum Sand <br />InunY Sand <br />1.20 <br />079 <br />1.00 <br />1 So <br />1o <br />.00 <br />.< <br />46w60 <br />swlra.y <br />Slit Clay Lam <br />0,45 <br />2.67 <br />1 to 120 <br />Silty say <br />SaM ary <br />0.24 <br />5.00 <br />ower Wet 1204 <br />•a umdd tartaw nth rnM haanm Put.= <br />