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��µ <br /> OSTP Trench Design UNIVERSITY <br /> Minnesota Pollutbn Worksheet OF MINNESOTA <br /> tontrol Agency ��� <br /> 1. SYSTEM SIZING: Project ID: v 07.14.15 <br /> A. Design Flow: 225 GPD <br /> B. Code Maximum Depth: 24 inches Designers Maximum Depth: 24.0 inches <br /> C. Soil Loading Rate: 0.45 GPD/ft2 Contour Loading Rate: 12.0 gal/ft <br /> D. Required Bottom Area: Design Flow(1.A)=Loading Rate (1.C) = Initial Required Bottom Area <br /> 225 GPD= 0.45 GPD/ft2 = 500 ftZ <br /> E. Select Dispersal Media: ❑ Rock <br /> (selection required) p Registered Product <br /> F. Select Distribution Method: 0 Pressure ❑Gravity-Drop <br /> ❑Gravity-Other <br /> G. If distribution media is installed in contact with sandy or loamy sand or with a percolation rate of 0.1 to 5 mpi <br /> indicate distribution or treatment method: <br /> 2. TRENCH CONFIGURATION: ROCK <br /> q. Initial required Sidewall gottom Area Bottom Area Design <br /> trench bottom area Absorption trench <br /> Reduction Multiplier <br /> (ftZ): (from 1.D) (inches) bottom area cover <br /> 6 to 11 1 500 <br /> Q Distribution <br /> 12 to 17 20% 0.8 <br /> 500 <br /> 18 to 23 34% 0.66 5idewalt <br /> 24 40% 0.6 <br /> B. Select Sidewall Height: �inches = �ft <br /> widcn <br /> C. Design Bottom Area (2.A): �ftZ <br /> D. Select Trench Width: �ft <br /> E. Total Designed Trench Length: Bottom Area :Trench Width =Total Required Trench Length <br /> �ft2 -� ft= �ft <br /> I. Calculate Minimum system length based on Contour Loading Rate: Design Flow =Contour Loading Rate = <br /> ��Pd:��al/ft = �ft <br /> F. Select No. of Trenches: �trenches <br /> G. Select Trench Spacing : �ft (typically 5 - 12 ft from center to center) <br /> H. Calculate Lawn Area:Trench Length (2.E)X Trench Spacing (2.G)=square feet of lawn area <br /> � ft X�ft = �ft2 lawn area <br /> J. Select Depth Required to Cover Distribution Pipe: <br /> �ft (0.33 ft for pressure, 0.5 ft for gravitY) <br /> K. Calculate Rock Volume: (Sidewall Height(2.6) + Depth to Cover Pipe (2.J))X Bottom Area (2.C) =cubic feet <br /> ( �ft +�ft� X�ftZ = ft' <br /> Divide ft'by 27 ft'/yd'to calculate cubic yards: <br /> �ft3 + 27 = �yd3 <br />