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Register your septic tank / package sewage treatment plant

Your home may use a septic tank or package treatment plant to deal with your domestic sewage because it cannot be connected to the public sewerage system. Find out if you need to register

Who needs to register

If your home or property is in Wales and has a septic tank or package sewage treatment plant, it is a legal requirement for you to register it with us.

For most people this is a free and a one-off registration, subject to certain criteria:

  • If your septic tank discharges into a soakaway in the ground and the domestic property or properties has less than 13 people living there
  • If your package sewage treatment plant discharges to a watercourse, and the domestic property or proprieties has less than 33 people living there
  • If the sewage system is not near a protected or designated area for the environment, groundwater or drinking water supply. For example, a Site of Special Scientific Interest (SSSI) or a Source Protection Zone for drinking water. We can check this for you once we have received your application

Septic tanks discharging directly to surface water do not qualify for an exempt registration. A septic tank discharging directly to surface water would not met our permitting requirements and the system would need to be improved.

Natural Resources Wales (NRW) does not have a specific date by which a septic tank discharging to surface water needs to be upgraded, but it could be done initially and included as part of the permit application. Or we could consider issuing a permit with an improvement condition that would require improvements to the system at a later date.

This date may be a short/long term depending on the sensitivity of the receiving environment and the specifics of each case.  

Any improvements do not necessarily have to be via a Private Treatment Plant system. A discharge to ground via an infiltration system may be required, for example.

Discharge in Sewered Areas:

You must connect to the public foul sewer where the discharge is within a sewered area (eg where a single dwelling is within 30 metres of the public foul sewer).  Registration of a new discharge is not possible where it is feasible to connect to the public foul sewer.

If you are in a sewered area and still want to apply for an environmental permit to discharge you should note that; we would only grant a permit where you can clearly demonstrate there are overall benefits for sustainability, there will be no environmental impact, and it is not feasible to connect to a public or other private foul sewer due to the cost and/or practicability.

If you meet the above criteria you will be able to register for a free exemption.

If you do not meet the above criteria you will not be eligible to register for a free exemption and you will need to apply for an Environmental Permit.

If your proposed discharge is into a main river you may require a Flood Risk Activity Permit or Exemption. You can find further information on environmental permitting for flood risk activities here.

Why we need you to register 

Most septic tanks or package sewage treatment plants do not cause problems if they are well designed, installed and maintained.

The discharge from poorly maintained systems could:

  • pollute rivers, streams or underground water
  • contaminate sources of drinking water
  • harm nature conservation sites

It is very important that as an owner, you keep your septic tanks and package sewage treatment systems in good order.

How to register:

Register your septic tank/package sewage treatment plant here.

Once registered your exemption details will appear on the water exemption public register

In registering an exemption you are agreeing that you will comply with Natural Resources Wales’ guidance for design, construction, siting and operation of your sewage treatment system and that you will adhere to the manufactures’ specification. You are also agreeing to keep all records of maintenance for 5 years after work has been carried out.

Refer to Natural Resources Wales’s guidance below before you apply for a registration.

Help with your application

If you have any questions about your registration please telephone us on 0300 065 3000 (Monday to Friday, 9am-5pm).

How do I get a National Grid Reference?

To find out the grid reference go to the UK Grid Reference Finder website

  • Enter your postcode
  • Locate the position of your septic tank
  • Click the right hand button on your mouse at this location
  • Your 12 digit grid reference will appear

What happens next?

We will inform you within 15 working days (three weeks) if your registration has been successful.

If we cannot accept the registration for any reason we will let you know. You may need to apply for an environmental permit. There is a one-off charge for a permit application for a small sewage discharge. This is our 'reduced application fee', which is currently £125.

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