Sewage System Components and Guide to Developing Your Own
Septic tank
A septic tank is a two or three chamber system, which retains sewage from a property for sufficient time to allow the solids to form into sludge at the base of the tank, where it is partially broken down. The remaining liquid in the tank then drains from the tank by means of an outlet pipe.
Effluent from a septic tank is normally disposed of by soakage into the ground, provided that the disposal does not generate a pollution risk to surface waters or groundwater resources (underground water). The most commonly used form of soakaway is a subsurface irrigation area, comprising a herringbone pattern of land drains laid in shallow, shingle filled trenches. The soakaway drains should be located at as shallow a depth as possible, usually within 1 metre of the ground surface
Cesspool
A cesspool is a covered watertight tank used for receiving and storing sewage and has no outlet. It relies on road transport for the removal of raw sewage and is therefore the least sustainable option for sewage disposal. Because of this, a cesspool is best regarded as a temporary measure pending a more satisfactory solution, such as the provision of mains drainage. It is essential that a cesspool is, and remains, impervious to the ingress of groundwater or surface water and has no leaks.
Building your own Sewage System
You must provide evidence that a connection to the public sewer is not feasible.
Other than very exceptionally, providing non-mains drainage as part of your Planning or Building Regulation application will not be allowed unless you can prove that a connection to the public sewer is not feasible. Non-mains drainage systems are not considered environmentally acceptable in publicly sewered areas. You should note that the existence of capacity or other operating problems with the public sewer are not valid reason for non-connection where this is reasonable in other respects.
Where connection to the public sewer is feasible, agreements may need to be obtained either from owners of land over which the drainage will run or the owners of the private drain.
