Exempt Private Water Supplies

Most small, domestic supplies are classed as exempt supplies. If you or the other users on your supply do not use the water for commercial purposes it is likely that you are on an exempt supply.

The legal definition of Exempt supplies is those that fulfil the following criteria:

  • domestic supplies providing less than 10m3 of water per day, or
  • supplying less than 50 people.

If any of the properties on your supply are used for commercial purposes (including holiday lets) or the supply serves more than 50 people, your supply is classified as a ‘Regulated supply’ and you should refer to this section for advice.

Local authorities have a duty to take action if the quality of water from a private supply to any premises in their area poses an immediate risk to health.

Your local authority does not have a duty to take annual water samples or update risk assessments, but if you have concerns about the quality of the water they must test it for you.

It is still important that you improve your supply to ensure you and your family and guests all have access to wholesome water.

Risk Assessment

Exempt supplies are not required to have risk assessments carried out, but your local authority must provide advice on request. Information on risk assessments can be found in Section 4 of the PWS Technical Manual.

To help you identify the risks present on your supply and how you can improve it, simple risk assessment case studies are available here.

All supplies are different and so it is not possible to provide a ‘one size fits all’ treatment solution for your supply. Technical advice is available for:

Your local authority environmental health department can help you to conduct a more detailed risk assessment to look at the risks present on your supply and give advice on how to improve it. There may be a charge for this service, water quality analysis costs will depend on the analysis carried out. Contact the relevant local authority for further information.


Non-means tested grant funding is available for upgrading your supply and details for this can be found here.

If there is more than one property on the supply you can combine the grant funding to fund more expensive or collaborative treatment options (e.g. sinking a new borehole or replacing lead pipes).