Risk assessment of private water supplies

Last Updated: 7 September 2021

We carry out risk assessments for private water supplies. We charge for risk assessments.

  • you have to get a risk assessment if you have a newly registered supply, you will need a new risk assessment every five years
  • you don't have to get a risk assessment if your supply is for a singe domestic dwelling. But you can still ask us to do one for you

Charges for risk assessments

A risk assessment identifies potential risks to your water supply.

A risk assessment involves assessing:

  • the supply source, the surrounding area, identifying any potential or present forms of contamination
  • storage tanks and pipework are in good condition and free from ingress or contamination
  • treatment systems and maintenance records
  • general standard of the private water supply in accordance with the regulations

You will be given a report with the findings of the risk assessment. It will let you know what you need to do to bring the supply up to standard.

If the risk assessment reveals that there is a risk to public health we may issue an improvement notice.

Risk assessments for landlords, tenants and businesses

If you are a landlord or tenant, or you own or run a business that has a private water supply, you have responsibilities to make sure your staff, visitors, tenants and guests have access to safe water.

Your supply must:

  • be risk assessed by us at least every five years, and your risk assessment must be kept up to date
  • have at least one sample taken by us annually to show that your supply is safe and complies with the legislation

The number of water tests carried out on your supply during a year will depend on the number of people drinking from it.

Testing your private water supply

If you have a single domestic dwelling with no commercial interests, you don't have to do a risk assessment. 

Drinking water safety plan

A Drinking Water Safety Plan (DWSP) is usually needed once you have done your risk assessment. 

A DWSP is essential so that, if something goes wrong with your supply or water quality, everyone on the supply knows what needs to be done. It helps show who is responsible and helps to ensure maintenance is carried out.

We will help you produce the plan, there is no additional charge. You can also find advice on DWSP's from The World Health Organisation.  

A DWSP looks at each part of the water supply and outlines:

  • a layout of the supply and what properties it supplies
  • explains each part of the supply for example source, storage tanks, treatment system
    • is it fit for purpose?
    • can it cope in normal circumstances?
    • can it cope in an emergency?
    • what maintenance is needed?
    • who maintains it and are they sufficiently trained?
    • who checks work is completed?
    • what to do if the system breaks down?
    • can it be vandalised or terrorised?
  • in an emergency, what is the alternative source of water?