Laserfiche WebLink
MOUND DESIGN WORK SHEET(For Flows up to 1200 d) <br /> A. Average Design FLOW A-1: Estimated Sewage Flows In Gallons per Day <br /> number o <br /> Estimated (000 gpd(see figure A-1) bedrooms class I class II class III Class Iv <br /> or measured x 1.5 (safety factor) = gpd 2 300 225 180 60% <br /> 3 450 300 218 of the <br /> 4 600 375 256 values <br /> B. SEPTIC TANK Capacity 5 750 450 294 In the <br /> 6 900 525 332 Class I, <br /> a—/M Uallons (see C-1) 7 1050 600 370 II, or III <br /> g re 8 1200 675 408 columns. <br /> C. SOILS (refer to site evaluation) c-i: Septle tca ddes ons <br /> Number of Minimum la id la d with Lith d capacity <br /> 1. Depth to restricting layer= .yT-;o feet Bad== ity �p �'lifc�a& <br /> 2. Depth of percolation tests= /. y feet 2 or Its 750 1125 1500 <br /> 3. Texture � � �.o14we 3or4 1000 1500 2000 <br /> 5 or 6 1500 2250 3000 <br /> Percolation rate mpi 7,sor9 2000 3000 <br /> 4. Soil loading rate .4s'- gpd/sqft(see figure D-33) <br /> 5. Percent land slope 5 <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply average design flow (A)by 0.83 to obtain required rock layer area. <br /> (,00 gpd x 0.83 sqft/gpd = y-a),t� sqft- ic)% - <'Ll7 n <br /> 2. Determine rock layer width= 0.83 sqft/gpd x linear Loading Rate (LLR <br /> 0.83 sqft/gpd x. I L gpd/sqft= iv ft Mound LLR <br /> 3. Length of rock layer= area-:_width= <br /> S y 7 Sgft(Dl) = . 0 ft (D2) = ss ft < 120 MPI < 12 <br /> E. ROCK VOLUME > 120 MPI < 6 <br /> 1. Multiply rock area (D1)by rock depth of 1 ft to get cubic feet of rock <br /> 1411 sgft x 1 ft= IS L4 17 cult <br /> 2. Divide tuft by 27 tuft/cuyd to get cubic yards <br /> 1 1) - tuft +27 cuyd/cult= a o cuyd <br /> 3. Multiply cubic yards by 1.4 to get wei ht of rock in tons <br /> a cuyd x 1.4 ton/cuyd a tons <br /> 'D-33: Absorption Width Sizing Table <br /> F. SEWAGE ABSORPTION WIDTH Minuttees� Soil Texu re ��;g" Absorption <br /> per day M Ratio <br /> stere foot <br /> Fester than 5 Coarse Sand 1.20 1.00 <br /> Medium Sand <br /> Absorption width equals absorption ratio (See Figure D-33) FIM.Sen° <br /> 1.50 <br /> times rock layer width (D2) a1 to asi t am 00:60 2221006 <br /> Silt <br /> x 1 ft= �:�l�, ft a6 to 6o Sandy Clay 0.45 2.67 Low <br /> Sil Clay at <br /> 61 to 120 Silty day 0.24 5.00 <br /> Send a ay <br /> Slower than 120' <br /> •System datipnd for tbm soils twn be otbw m pmfonn mo <br />