It’s the classic conundrum. Do you get a cesspit installed for your property, or a septic tank? Although both cesspits and septic tanks collect wastewater and sewage from households and businesses that are not connected to the mains sewer, there are significant differences between the two.
We’ve put together some information about how they work and which one might be best for you. If you’ve already got one, we’ve also got some tips on how best to use and maintain your septic tank or cesspit to ensure it runs smoothly.
When a household cannot connect to the mains sewerage system, wastewater can be disposed of via a septic tank or cesspit. Although there are similarities and differences between the two systems, you might find that one will suit your situation better than the other.
Below, we’ve attempted to explain a little more about how both work, how to maintain them and when you might want to use one over the other.
What is a cesspit?
A cesspit is a sealed, fully-enclosed tank that collects wastewater and sewage. Cesspits don’t process or treat the waste in any way. A cesspit is usually located underground with a manhole cover giving access for waste collection.
If you have a cesspit on your property, you don’t need to register it. However, if you plan to install a new one you will need building regulations approval and planning permission before you start.
How does a cesspit work?
A cesspit is purely a holding tank without an outlet. The cesspit is connected to the drainage pipes within the property. It will have an exhaust or vent to allow the escape of gases which build up in the tank. Cesspits are discreetly buried underground with a single manhole cover for access by the waste collection team.
Cesspit Maintenance and Emptying
Cesspits need to be emptied regularly to prevent them from overflowing. Depending on the size of the property, this could be at monthly, quarterly or annual intervals. This can only be done by a professional waste removal team and a tanker, and it can be pricey. It’ll cost the average person about £2,000 a year in emptying charges. This goes up to about £8,000 a year for a family of four.
No matter how much it costs, do not attempt to empty a cesspit yourself! Even opening the manhole is a bad idea as the fumes can quickly overpower you. Always get a waste removal company to do it.
When should a cesspit be used?
Rarely if possible. Cesspits are generally used where the ground is unsuitable for the waste to be treated by a soakaway. This is could be because of the lack of a ditch, stream or surface water drain. It can also include sites close to water sources or drinking water supplies. If the property is only used infrequently, like a rural church for example, then a cesspit may be the most cost effective option. Otherwise, avoid their use where you can.
Cesspits are not an option for most modern houses as they require a lot of room for the installation. Cesspits can also smell very badly as they are vented to allow excess sewage gas to escape. There is also the risk that they will overflow or leak, which can land you with a £20,000 and 3 months in prison.
If you’re thinking of buying a property with a cesspit, make sure you get a full survey carried out. This will identify if there are any holes or leaks in the tank. You should also think very carefully about the enormous running costs of having a cesspit.
What is a septic tank?
A septic tank is a tank that collects wastewater and sewage from properties that are not connected to the mains server. Septic tanks are buried underground and contain two chambers. A well designed and maintained concrete, fiberglass, or plastic tank should last about 50 years.
You need to make sure you meet the ‘general binding rules’ of owning a septic tank. These rules state that the sewage must be domestic, and must not cause pollution. If you don’t meet these general binding rules you need to apply for a permit from the Environment Agency.
How does a septic tank work?
A septic tank will separate the waste it into different chambers within the tank. Unlike cesspits, they use a simple treatment process on the waste. As wastewater enters the first tank, solids settle at the bottom and begin to decompose. The liquid flows through to the second chamber.
Here, the treated liquid is able to drain away to a soakaway or stream. A soakaway is a hole dug in the ground and filled with rubble and coarse stones, designed to disperse water back into the surrounding ground without flooding.
Septic tank Maintenance and Emptying
It’s advisable to have waste removed from the septic tank regularly, ideally every six months but at least once a year. Bacteria in the tank is vital to the biological decomposition process, so over-use of biological cleaning products and bleach is not recommended. Always use a professional waste removal company to maintain and empty your septic tank.
Failure to empty a septic tank can result in solid waste emptying into the soakaway soil. This very quickly blocks the air spaces in the soil so the effluent cannot soak away. A soakaway failure occurs and the septic tank fills up, backing up the system.
Most common septic tank problems and failures, with both brick and fibreglass ones, are due to the soakaway drainfield and not to the septic tank itself.
Eventually a septic tank soakaway drainfield will fail. How quickly the septic tank soakaway becomes a failure depends on several factors. These factors include the nature of the soil, how often the septic tank has been emptied, heavy rain periods and the deterioration of the septic tank itself, amongst others.
All septic tanks whose effluent finds its way into ditches or streams, either directly, or by mistake, have to be replaced with sewage treatment plants by 1 January 2020, or before this date if the property is sold.
When should a septic tank be used?
In the UK, septic tanks are generally used in rural areas, away from the mains server. If your property is out in the sticks, a septic tank is a much better option than a cesspit due to their efficiency, longevity and lower associated costs.
If you’re thinking of buying a property with a septic tank, make sure an inspection of the tank is part of the survey. A faulty tank can damage the environment, damage your home and land you in hot water with the environment agency.
If you’ve got a cesspit or septic tank that you need emptied or maintained in London, Middlesex or Hertfordshire, call in the experts.
Whether you require a regular or one-off waste removal service, you can rely on Drain 247 and our experienced, insured and licensed engineers. Our engineers are on call 24 hours a day, 7 days a week, 365 days a year. We also have an emergency response service that can get our engineers to you rapidly for urgent requirements.