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Septic tanks and Private Sewage Treatment Systems

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If your property isn’t connected to the public sewer, you likely use a private sewage treatment system—such as a septic tank or package treatment plant. These systems treat wastewater from one or more properties and discharge it to land or water. By law, all discharges must be registered with SEPA.

Types of discharges

  • New discharges: Systems less than 2 years old or not yet in use (for example, if you're still in the planning stage of building a house or business).
  • Existing discharges: Systems in use for more than 2 years

New discharges must connect to the public sewer where possible. If you have a new sewage discharge, you should contact Scottish Water for more information about connecting to the public sewer. If you can't connect to the public sewer, you will need to apply to SEPA to register your discharge.

If your discharge is grey water or liquid from a composting toilet, you can't apply online. Read composting toilets and grey water for more information.

How to register

Register a small sewage discharge

Registering a new discharge

You can apply to register online if your discharge is:

  • from up to 10 domestic properties; or
  • from a combination of domestic and non-domestic properties that serve a population equivalent (p.e.) of up to 50

Our online application service will help you decide what type of treatment system you need. You must pay a registration fee when you apply for a registration. The registration fee for a small sewage discharge is £190.

If your discharge exceeds these limits, you will need to apply for a licence instead. Please read how to apply for a licence to discharge sewage effluent (word 287kB).

All registered activities are subject to conditions. This is to prevent pollution.

When you register a small sewage discharge, you must meet the conditions of your registration. This includes properly maintaining your private sewage treatment system. To find out more about the conditions that apply to small sewage discharge registrations, please read our registration guidance.

Registering an existing discharge

You can apply to register online if your discharge is from nine properties or less.

If your existing discharge is from 10 properties, you can't apply online. You should apply for a registration by completing an application form and emailing it to our Registry Team.

If your existing discharge is from more than 10 properties, you will need to apply for a licence. Contact us by emailing the Water Permitting Team to discuss.

An untreated discharge is a discharge that doesn't go through any type of treatment before discharge to land or water. If your existing discharge is untreated, you should contact us by emailing the Water Permitting Team.

What you will need

  • Property addresses and contact details
  • Type and age of the treatment system
  • Discharge location (to land, water, or sea)
  • Soil percolation test results (for land discharges)
  • Population equivalent (for non-domestic use)

If you are unable to register using our online service

It's quicker and easier to register your sewage discharge online, if you are unable to you can still apply by completing one of the application forms listed below and emailing it to our Registry Team.

If our service told you that your registration could not be completed online, read our registration guidance for information about what to do next.

Maintaining your system

Proper maintenance is a legal requirement and helps prevent pollution. You should:

  • De-sludge annually
  • Follow manufacturer’s servicing instructions
  • Check soakaways and outfall pipes
  • Avoid flushing fats, oils, or non-biodegradable items

For shared systems, maintenance responsibilities are shared among connected properties. Read full maintenance guidance

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