sing siphon Typical pump curve Digging an absorption trench Cross section of an absorption trench Gravel voids filled with dirt Installing filter fabric Distribution pipe configurations Distribution box Drop boxes Measuring the slope of the trench bottom with a carpenter's level Measuring the slope of the trench bottom with an "Arkansas" level Backhoe bucket with side teeth to rough up sides of trench Cemented gravel Clay pipe joints Deep trench Seepage pit Seepage pit liner construction Seepage pit outlet pipe Looped distribution system in a seepage bed Leaching chamber Alternating fields Diversion box Elevated drain field Elevated drain field on a slope Sand mound system components Cross section of a mound Available absorption areas on flat and sloping ground Example mound design Example mound design Example distribution system design Laterals located below manifold Lateral extension for access Flood irrigation system Sprinkle irrigation system Trickle irrigation system and emitter Shallow subsurface irrigation system Low pressure system loading rates Shallow subsurface plot and distribution system Cross section of a shallow subsurface trench Tamped earth dams Elevated sand filter Uncollected sand filter trench Sand filter in highly permeable soil Effective size and uniformity of sand Collected subsurface sand filter Intermittent sand filter Recirculating sand filter Proportional flow controls Evapotranspiration system United States evaporation rates Effects of plants on evaporation rates Change in water levels in ET bed Polyethylene sheeting joints Pipe penetration of liner ET distribution system Distribution system cross section Large volume composting toilet Small volume composting toilet Grey water system components Separate grey water tank Simple sand filters Cartridge filtration Disinfection unit Contact chamber Troubleshooting Flush toilet List of Tables Comparison of typical septic tank and aerobic unit effluents Soil classification Example percolation rate calculation Relationship between soil type and