Septic Tank Guidelines

Oxfam (2008) C1
A septic tank takes raw sewage in, allows the solids to settle (sludge) and allows the remaining liquid to flow into the surrounding soil by means of a soakaway. Scum on the surface is also prevented from leaving the tank. Microorganisms in the anaerobic environment in the tank digest the sludge and scum. The system consists of several stages, supply to the tank, the tank itself and the soak field.