Cesspools and Septic Tanks – What Is The Difference?

Understanding the difference between a cesspool and a septic tank can be vital to householders to fully understand and manage their drainage system, or to help you make an informed decision when purchasing a property.

Septic Tanks

Tilley, E., Ulrich, L., Lüthi, C., Reymond, Ph., Zurbrügg, C.

A septic tank is often a popular solution to sewage treatment for home owners not on the mains sewer system. Modern septic tanks tend to be made of reinforced fibreglass although older tanks may be constructed of concrete. The tank is water tight and sewage coming in from the property separates out into three distinct layers. Organic matter which floats to the surface as scum gradually becomes liquified through bacterial action. Waste matter or sludge from that decomposition process settles at the bottom of the tank, and the remaining clear water is able to flow slowly out through the outlet of the tank and back through the soil into the water table.

Cesspools or Cesspits


Olek Remesz

Cesspools are more primitive holding tanks for raw sewage and simply allow tainted water to leach out through the walls of the pit into the surrounding ground. Solids should decay and compost at the base of the pit, but because the tank is sealed it will require much more frequent emptying than a similar sized septic system Cesspools are also much more vulnerable to flooding from heavy rains or snow melt, and can be at risk of allowing untreated water to contaminate the water table. Tree roots are another risk to cesspools which can be penetrated by root growth which can cause blockages and overflows resulting in raw sewage backing up into the property, or breaching the hatch and flooding the garden where the cesspit is usually located in a domestic situation.



Considerations For Off Grid Sewage

When selecting a sewage system for your home or business it is important to fully understand the requirements in terms of access, number of users, and potential ongoing costs and maintenance. Septic tanks are the better solution as they comply with modern environmental regulations and will need much less maintenance and less frequent sludge removal than cesspools. At South West Drainage Services we can provide expertise in repairing or replacing cesspools and septic tanks, and can identify and resolve blockages in your system. We have a tanker available as part of our vehicle fleet for disposal of sludge and sewage materials and all materials are disposed of at licenced sites in accordance with our Environment Agency registration.

Get in touch for help with septic tank sludge removal or any other septic tank or cesspool related queries.