G030: Septic tank and aqua privy design

Using water to flush faeces away from a toilet ensures that the waste is separated from the user, helping to control smells and flies. It allows the toilet facilities to be located inside the home, for the convenience and security of the user, especially women and housebound people. The water used for flushing however now needs to be treated and if public sewers are not nearby, a septic tank provides a simple but effective method of removing the worst of the contaminants. This guide is about disposing of human wastes and sullage using septic tanks and aqua privies. It describes how they work and discusses how they are designed and constructed.