Cesspools and cesspits: the rules in England
How a cesspool differs from a septic tank, how often gov.uk says to empty it, who can make you fix it, and the size a new one must be.
Updated 15/10/2026. Every fact links to its source at the end of the page.
Cesspool or septic tank?
A septic tank is an underground tank where solids sink to form a sludge and the waste water flows out to a drainage field 2. If your system releases sewage into the ground or into surface water, it is not a cesspool 1.
If you are not sure which you have, gov.uk says to ask a local installation or maintenance company 1.
The rules for a cesspool
The general binding rules for septic tanks and treatment plants do not apply to cesspools 1. Instead you must maintain your cesspool and make sure it 1:
- is emptied regularly, for example once a month, by a registered waste carrier
- does not leak or overflow
You do not need a permit unless the Environment Agency tells you that you do 1.
If it is in poor condition
The Environment Agency or your local council can make you repair or replace your cesspool if it is in poor condition 1. You are breaking the law if your cesspool causes pollution 1.
Checking the firm that empties it
The firm must be a registered waste carrier 1. The Environment Agency publishes information about permissions on public registers that anyone can see. Its page says to check the public register to find registered waste carriers, brokers and dealers 3.
Putting in a new cesspool
You must get planning permission and building regulations approval 1. A new cesspool must hold at least 18,000 litres for 2 users, plus 6,800 litres for each extra user 1.
What we don’t cover
We have not found an official source for what emptying or replacing a cesspool costs, so we do not quote a figure.
Sources
- Septic tanks and sewage treatment plants: your property has a cesspool GOV.UK (Environment Agency) (gov.uk). Checked 15/10/2026.
- General binding rules: small sewage discharge to the ground GOV.UK (Environment Agency) (gov.uk). Page updated 23/07/2026. Checked 15/10/2026.
- Access the public register for environmental information GOV.UK (Environment Agency) (gov.uk). Page updated 07/04/2026. Checked 15/10/2026.