Septic systems

The first component of a septic system is a septic tank. This is a big (generally around 3,000 litres) concrete or brick tank that is buried in the ground. There is a layer of scum with sludge below it. In the sludge, microbes break down the wastes before the treated sewage moves into agricultural pipes that allow the wastes to be gradually absorbed by the soil in the garden. Microscopic bacteria, both in the septic tank and in the soil, play an important part in the gradual treatment of sewage that enters a septic system. However, this is not as effective as the treatment provided by a modern sewage treatment plant and problems often occur when septic systems are not maintained regularly. Such problems can result in untreated sewage flowing into the sea through creeks and streams.