Rules you must follow if your septic tank or small sewage discharge treatment plant releases (discharges) liquid to a surface water.

Published 16 June 2015
From:
Environment Agency
Contents
Rules for existing and new treatment systems
Additional rules for new treatment systems installed and in use on or after 1 January 2015
Enforcement and sanctions
You must read septic tanks and treatment plants: permits and general binding rules before you follow this guidance.

New rules came into force on 1 January 2015. If your system was installed and discharging before 31 December 2014 you have an ‘existing discharge’. If your system was installed and discharging on or after 1 January 2015 you have a ‘new discharge’.

Rules for existing and new treatment systems
Use the correct treatment system
You must use a small sewage treatment plant to treat the sewage if you’re discharging to a surface water such as a river or stream. A small sewage treatment plant (also known as a package treatment plant) uses mechanical parts to treat the liquid so it’s clean enough to go into a river or stream.

Discharges from septic tanks directly to a surface water are not allowed under the general binding rules.

If you have a septic tank that discharges directly to a surface water you will need to replace or upgrade your treatment system by 1 January 2020, or when you sell your property if before this date.

If the Environment Agency finds evidence that your septic tank discharging to a surface water is causing pollution, you will need to replace or upgrade your system earlier than 1 January 2020. You will usually have to do this within 1 year, although this will be agreed on a case-by-case basis.

You may be able to:

connect to mains sewer – where available
install a drainage field (also known as an infiltration system) so the septic tank can discharge to ground instead
replace your septic tank with a small sewage treatment plant
Contact the Environment Agency to discuss your options.

Further information general-binding-rules-small-sewage-discharge-to-a-surface-water