Cesspools, cesspits and Septic tanks - Effluent Removal

 

Cesspools and Cesspits

Cesspools and cesspits are storage tanks, usually underground, which store sewage until it can be disposed of.  They are usually found in rural areas where the normal sewerage systems cannot reach the property concerned.  Modern cesspits are made of fibreglass or other similarly study materials however old ones were often made of brick.

 

They operate via an inlet pipe from the property and must be watertight to prevent the leakage of odour and foul water as well as the ingress of groundwater.

 

Cesspools must be emptied frequently and this is done by a drainage contractor who will pipe the contents of the cesspool away via a tanker.  Melton Borough Council do not offer this service.

 

Common Problems

Some older cesspools will have an overflow pipe onto the surface.  These no longer conform to modern standards and must never be allowed to overflow as this will result in the release of raw sewage onto the land and permeate into groundwater.

 

Brick built cesspits can be prone to leakage, particularly as they are susceptible to deterioration.  Again care must be taken not to allow leakage and pollution.  To do so may be a prosecutable offence.

 

Leaking connections can occur from where the pipework leaves the property to where it joins the tank.  Regular checks should be made to avoid leakage and pollution.

 

Septic Tanks

A septic tank is similar to a cesspool, but has the important difference that it only stores the solid material and allows partly treated liquid (effluent) to run away from the tank, either to further treatment, or a system of underground land drains.

 

The raw sewage enters the septic tank via an inlet pipe, which slows down the velocity of the sewage and does not disturb the surface as it enters the tank. As the water slows, it cannot carry so much solid material in suspension and a sludge drops to the bottom of the tank. Due to the very slow movement through the tank, a scum (known as the crust) will form on the top surface of the tank. This allows the growth of anaerobic (oxygen hating) bacteria. This bacteria sets about digesting or breaking down the solid material at the bottom of the tank, and turns it into liquid form, which then leaves the tank via the outlet. Not all the solid material will be broken down by this action so that over a period of time there is a build up of sludge which has to be pumped out by a licensed contractor every 12 months depending upon usage.

 

The effluent that leaves the septic tank is untreated. The effluent is therefore passed into the subsoil via a network of drains which either have perforations or are laid in such a way that the effluent can trickle out of the drains into the surrounding ground.

 

Further information

For more general information on cesspits, cesspools and septic tanks please refer to this Septic Tank information leaflet.

 

A private drainage contractor should be sought for repairs, maintenance and emptying of cesspits.  Melton Borough Council cannot recommend particular businesses. ]