Laserfiche WebLink
A. <br />Trench a Bed Design Worksheet <br />SYSTEM SIZING: <br />A. Design Flow: <br />C. Loading Rate: <br />UNIVQM$ITY or MNm,strm <br />600 IGPD B. Maximum Depth: I 24 inches <br />0.60 Ift2/GPD <br />D. Required Bottom Area: Design Flow (1.A) + Loading Rate (1.C) = Required Bottom Area <br />I 600 I_ I 0.60 I= I 1000 ft2 <br />E. Select Dispersal Media: <br />F. Select Distribution Method : <br />G. Select Dispersal Type : <br />TRENCH CONFIGURATION: <br />Required trench Sidewall <br />bottom area (ft2): Absorption <br />(from 4A) (inches) <br />6 to 11 <br />1000 <br />B. Select Sidewall Height : <br />C. Required Bottom Area : <br />D. Select Trench Width: <br />❑ Rock ❑ Chambers 0 Gravelless Pipe <br />❑ Other Approved Media I rock or geo covered chambers <br />❑ Pressure (required for rapidly permeable soils) <br />❑ Gravity -Drop Box <br />❑ Gravity -Other <br />❑ Trench ❑ Bed (<6% Slope) <br />Bottom Area Bottom Area <br />Reduction Multiplier <br />0% 1 <br />Reduced <br />trench <br />bottom area <br />1000 <br />12 to 17 20% 0.8 800 <br />18 to 23 34% 0.66 660 <br />24 40% 0.6 600 <br />12 inches = I 1.00 Ift <br />800 Ift2 <br />3.0 Ift <br />gravity - drop box <br />}Cover <br />0 Distribution <br />Width <br />E. Total Required Trench Length: Bottom Area (2.C) : Trench Width (2.D) = Total Required Trench Length <br />F. Select Trench Spacing <br />G. <br />H. <br />800.0 I ft2 _ I 3.0 I = I 266.7 Ift <br />8 Ift (typically 5 - 12 ft) <br />Calculate Lawn Area: Trench Length (2.E) X Trench Spacing (2.F) = ft2 lawn area <br />I 266.7 ( X I 8.0 I = I 2133.3 ft2 lawn area <br />If using rock or subsitutue, select Depth Required to Cover Distribution Pipe: <br />0.5 Ift (0.33 for pressure, 0.5 for gravity) <br />Sidewall <br />I. Calculate Rock Volume: (Sidewall Height (2.B) + Depth to Cover Pipe (2.H)) X Bottom Area (2.C) = cubic feet <br />(I 1.00 I + I 0.50 <br />X <br />800.0 <br />Divide ft3 by 27 ft3/yd3 to calculate cubic yards: <br />1200 I ft : 27 = ( 44 Iyd3 <br />1200 <br />ft3 <br />