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OSTP Mound Design u <br />NIVERSITY <br />Minnesota Pollution <br />Control Agency Worksheet > 1 % Slope op MrNNEsoTA <br />1. <br />2. <br />SYSTEM SIZING: Project ID: V 06.12.13 <br />A. Design Flow: 750 .· TABLE IXa <br />B. Soil Loading Rate: <br />I <br />I 0.45 <br />IGPD <br />=====:1GPD/ft2 LOADING RATES FOR DETERMINING BOTTOM ABSORPTION AREA <br />. AND ABSORPTION RATIOS USING PERCOLATION TESTS ===~ 1------..---=----~--=c-----'---,---:-,-.-,---{ <br />C. Depth to Limiting Condition: I <br />D. Percent Land Slope: I <br />E. Design Media Loading Rate: <br />1.0 <br />6.0 <br />ltt ===:::: <br />1% ===:::: <br />1.2 <br />Percolation Rate <br />(MPI) <br />Treatment Level C · Treatment.Level A, A-2, B, <br />·Absorption <br />. Mound Absorption • Mound Area Loading Area Loading <br />::Rate Absorption Rate Absorption <br />(gpd/ft2) . <br />·Ratio (gpd/lt') Ratio <br />. . I <br />F. Mound Absorption Ratio: I 2.70 <br />IGPD/ft2 <br /><0.1 =:::::::!1 ----------l 0.1 to5 <br />O 1 to 5 (fine sand <br />and loarnv fme sand\ <br />1 1 <br />1.2 1 1.6 1 <br />· f,\Qi;ISUf9d <br />P&rc Rat,;i <br />~ 60mpi <br />·.. Table I <br />MOUND CONTOUR LOADING RA TES: <br />.· <br />T&xturn • d,;,riw;,d <br />OR mound absorption ratio <br />1.0, 1.3. 2.0. 2.4. 2.6 <br />. <br />.contour <br />Loading <br />Ratll: <br />i12 <br />Gto 15 <br />1610 30 <br />31 to 45 <br />,tGloGO <br />61 to 120 <br />>120 <br />0.6 2 1 1.6 <br />0.78 1.6 1 1.6 <br />0.6 2 0.78 2 <br />0.5 2.4 0.78 2 <br />0.45 2.6 0.6 2.6 <br />. 5 0.3 5.3 <br />. <br />61-120 mpi OR 5.0 ;;12 <br />•systems with these values are not Type I systems. <br />2: 120 mpi" >5.0' !:6. Contour Loading Rate (linear loading rate) is a <br />recommended value. <br />DISPERSAL MEDIA SIZING <br />A. Calculate Dispersal Bed Area: Design Flow + Design Media Loading Rate = ft2 <br />I 150 IGPD + I 1.2 IGPD/ft2 = I 625 !n2 <br />If a larger dispersal media area is desired, enter size: I 630 jn2 <br />B. Enter Dispersal Bed Width: I 10.0 In Can not exceed 10 feet <br />C. Calculate Contour Loading Rate: Bed Width X Design Media Loading Rate <br />I 10 ln2 x I 1.2 jGPD/ft2 = I 12.0 jgal/ft Can not exceed Table 1 <br />D. Calculate Minimum Dispersal Bed Length: Dispersal Bed Area + Bed Width = Bed Length <br />I 630 ln2 + I 10.0 In =I 63.0 In <br />3. ABSORPTION AREA SIZING <br />A. Calculate Absorption Width: Bed Width X Mound Absorption Ratio = Absorption Width <br />I 10.0 In x I 2.1 I = I 21 .o In <br />B. For slopes >1%, the Absorption Width is measured downhill from the upslope edge of the Bed. <br />Calculate Downslope Absorption Width: Absorption Width -Bed Width <br />I 27.0 In -I 10.0 In =,-1 -17-.0---,lft <br />4. DISTRIBUTION MEDIA: ROCK <br />A. Media Volume: Media Depth X Length X Width <br />1.00 jft xi 63.o In x I 10.0 ltt = 1 630 1 ft3 + 21 = 1 23