underlying the new technology. Installers must consider siting, design, construction, installation, operation, and maintenance. This book provides easy-to-understand methods of proper septic system practices suited to a broad range of site conditions, and the reasons for using them. Potential problems, both with the system compo- nents and the people who regulate septic systems, are described and potential solutions provided. Contents Chapter 1 Introduction PART I: AN OVERVIEW OF ONSITE WASTEWATER DISPOSAL 2 Regulations and Processes Codes and Regulations The Treatment Process The Disposal Process 3 Selection of Site and System Site Evaluation System Selection System Location PART II: SYSTEM DESIGN, CONSTRUCTION, AND MAINTENANCE 4 Waste Process Septic Tanks Dosing Chambers Conventional Waste Disposal Systems Conventional Drain Fields Deep Absorption Trenches Seepage Pits Cesspools Absorption Beds Leaching Chambers 6 Modifications of Conventional Systems Alternating Drain Fields Elevated Drain Fields Sand Mounds Land Application Sand Filters 7 Low-Impact Systems Evapotranspiration Holding Tanks Composting Toilets Grey Water Systems Disinfection PART III: SYSTEM SUPPORT 8 Solving Problems Toilet Won't Flush Liquid Ponded Over Drain Field Siting and System Problems Infiltration Problems 9 Water Conservation Leaks Retrofits Behavior Appliances 10 Lot Evaluation Appendix: Formulas Bibliography Index List of Figures Typical septic tanks Typical aerobic treatment unit Drain field under construction Typical plot plan Determining number of people in household Moist sand cast Dry loam cast Ribbon of moist loam Clay ribbon Soil texture triangle Root depth and soil drainage capacity Soil peds Aggregated blocks of clay Clod of sandy loam Movement of water by capillarity Percolation test water supply Measuring drop in water level Determining soil conditions Measuring ground slope "Stacked" pipes Typical septic tank design Gas baffles Risers Measuring the scum layer Measuring the sludge depth Typical dosing chamber Automatic do