Risk assessing your private water supply

Last updated: 4 September 2018

A risk assessment checks the condition of your private water supply.

It involves:

  • assessing your supply's source, and the surrounding area, to identify potential sources of contamination
  • checking your storage tanks, any treatment systems and pipework
  • testing the quality of your water

Risk assessing your water supply will increase your knowledge of it.

Using the information from your risk assessment to take appropriate action will help protect, and improve, your water quality.

If you are a landlord or tenant, or you own or run a business that is served by a private water supply

You have specific responsibilities to make sure your staff, visitors, tenants and guests have access to wholesome water.

Your supply:

  • must be risk assessed by your local council at least every 5 years, and your risk assessment must be kept up to date
  • must have at least one sample taken by your local council annually to show that your supply is 'wholesome' and complies with the legislation (you may be charged for this)

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

So, for example, a large estate with 10 rented cottages will be tested more often than a single cottage.

Contact your local council for more information.

Whether you pay for these tests or pass them on to your tenant(s) will depend on what you have agreed. Sometimes landowners who own a lot of land charge all cottages a standard fee to use a water supply.

Drinking Water Safety Plan

A Drinking Water Safety Plan (DWSP) lists all the risks for a supply and what is being done, or needs to be done, in order to make sure your water supply stays safe.

Your local council can help you develop one.

If you have a small, domestic, non-commercial private water supply

If you have a small, domestic supply, having a risk assessment carried out by your local council isn't mandatory.

But you should consider asking your local council to carry out a risk assessment for you.

Things to consider include:

  • the quality of the water at the source under all conditions
  • ways that contaminants could enter the supply throughout the system
  • materials used in the supply and how they might affect the quality
  • any treatment processes - how appropriate and resilient are they?
  • your system's design. Does it keep the water safe after it has been treated?
  • is the maintenance of the system adequate?

Once you have identified the risks you can start to prioritise them, and list things that need to be done in order to control them.