gth X width Circle: Area = pi X radius² ONSITE WASTEWATER DISPOSAL Volume Rectangular Parallelepiped (box): Volume = length X width X height Cylinder: Volume = 1/3 X end area X height Sphere: Volume = 4/3 X radius3 Water Formulas Pounds day gpd 0.00000834 X flow in X concentration (mg/L) per = % availability pounds Concentration in mg/L = 8.34 X gallons per day X 1 million Gallons in a cylinder = (diameter in inches)2 X length in feet X 0.0408 Water horsepower = per Gallons minute X feet of head 3960 X efficiency Bibliography General Bender, W.H. "Soils and Septic Tanks," Agricultural Information Bulletin 349, U.S. Department of Agriculture Soil Conservation Service, Washington, DC (1971). "Design Manual: Onsite Wastewater Treatment and Disposal Sys- items," Office of Research and Development, Municipal Environ- mental Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH (1980). Goldstein, S.N., and W.J. Moberg, Jr. "Wastewater Treatment Sys- items for Rural Communities," Commission on Rural Water, Wash- ington, DC (1973). Hansel, M.J., and R.E. Machmeier. "On-site Wastewater Treatment on Problem Soils," J. Water Pollut. Control Fed., 52(3): 548-558(1980). Kaplan, O.B. Septic Systems Handbook (Chelsea, MI: Lewis Pub- lishers, Inc., 1987). Laak, R. Wastewater Engineering Design for Unsewered Areas (Ann Arbor, MI: Ann Arbor Science Publishers, Inc., 1980). Machmeier, R.E. "Town and Country Sewage Treatment," Exten- sion Bulletin 304, Agricultural Extension Service, University of Minnesota, St. Paul, MN (1980). "Manual of Septic-tank Practice," Public Health Service Publication No. 526, U.S. Department of Health, Education and Welfare, Washington, DC (1967). "Onsite Wastewater Management and Groundwater Protection," in Proceedings of the Third Annual Midyear Conference, February, 1988, Mobile, AL, National Environmental Health Association, Denver, CO (1988). 240 ONSITE WASTEWATER DISPOSAL Proceedings of the (1st.-8th) National Individual Onsite Wastewater Sys- tems Conferences, National Sanitati