Rather old design manual for onsite wastewater treatment options. However, valuable information on established systems such as septic tanks, sandfilters, aerobic treatment units (suspendend growth and fixed film), disinfection, nutrient removal as well as wastewater segregation and recycling are given. Additional information is given on disposal methods and appurtenances.
U.S. EPA (1980): Design Manual - Onsite Wastewater Treatment and Disposal Systems. (= EPA 625/1-80-0 ). United States Environmental Protection Agency and Office of Water Office of Research and Development URL [Accessed: 27.05.2019]