You are responsible for (the ‘operator’ of) a septic tank or sewage treatment plant if:

  • you own the property that uses the system
  • your property shares the system with other properties (you are jointly responsible)
  • you have an agreement with the owner of the property that you are responsible for the system, for example you’re renting and it’s in your tenancy agreement

If you connect your sewage system to the mains sewer (also called a ‘public foul sewer’) you do not need to do anything else and will not need a permit.

Your septic tank or treatment plant will treat your sewage and release liquid (‘sewage discharge’) into the environment. What you must do depends on:

  • whether the sewage discharge goes into the ground or into surface water
  • if the treatment system was installed or was changed significantly before 2 October 2023 (an ‘existing discharge’)
  • if the treatment system was installed or has changed significantly since 2 October 2023 (a ‘new discharge’)

There are different rules if you have a cesspool.

There are different rules for septic tanks and treatment plants in Northern Ireland, in Scotland, and in Wales.

Sewage discharges

A sewage discharge is where you release sewage to either:

  • the ground (for example in your back garden)
  • surface water (for example a river, stream, estuary, lake, canal or coastal water)

New discharges are ones that started or changed significantly since 2 October 2023. Check what counts as a new discharge and what to do if you have one.

Existing discharges are from systems installed before 2 October 2023 that have not changed significantly since then. Check what counts as an existing discharge and what to do if you have one.