Septic tanks and private sewage treatment systems

What is a private sewage system?

It deals with waste water not served by the mains sewer. For example, a septic tank.

It should not affect the environment if you look after it.

But if you do not look after it, it can affect:

  • human health
  • drinking water
  • protected areas

We have a simple information tool that explains everything you'll need to know. New users can register for the site at: Register - eNetLearn. Existing users can sign in at: sign in with Netregs. Once there go to your 'Workspace' and search for 'Septic Tanks'.

If you have a private sewage system you need to register it with us.

You’ll need proof of registration for new builds or as part of a sale.

Register a private sewage system

You can register your system online if the system:

  • is more than two years old; and
  • serves up to nine properties.

Alternatively, submit an application via our Registry mailbox if the system:

  • is less than two years old; or
  • serves more than nine properties.

Please email application forms, along with supporting information, to

Meeting the conditions of registration

If your application is successful we’ll confirm your registration.

You must meet the conditions of registration, which includes regular maintenance. Information on maintenance of septic tanks is available in the Septic Tank Guide. The British Water Guide for Users of Packaged Wastewater Treatment Plants is available on the British Water website along with other useful guidance documents. 

In England septic tanks need to be upgraded by 2020. This does not apply in Scotland.

Read the full Water Environment (Controlled Activities) (Scotland) Regulations 2011

Read the amendments to the regulations

Or read our summary of the regulations

Restarting private sewage treatment systems following shutdown

British Water have produced guidance for restarting package sewage treatment plants and a list of suitable maintenance engineers can be found on their website.

COVID-19 will have resulted in a period of low or no flow of sewage effulent to a number of private sewage treatment plants. Restarting the plant could cause pollution due to the biological processes not yet working properly to treat the effulent. If you are unsure of how to proceed, then tou are advised to seek technical advice on restarting.

Get further help

Please contact us if you:

  • are registering a system serving three or less properties, has been in use for two or more years and need help completing the application contact us.
  • have another enquiry that is urgent and requires resolution in the next three weeks.