Cookie consent

We use cookies to track how you use our website to help improve your experience and show you personalised content. You can accept the use of all cookies or manage them individually. You can find out more about your options by clicking “manage cookies".

Strictly necessary/functionality cookies

Necessary cookies enable core functionality. The website cannot function properly without these cookies, and can only be disabled by changing your browser preferences.

Find out more about our cookies

Drinking Water

Due to their properties, PFAS build up in the environment and may be present in water resources (surface water and groundwater) used to abstract drinking water.

There are no regulatory standards for PFAS in drinking water in England and Wales. Water quality regulator the Drinking Water Inspectorate (DWI) has issued non-statutory guidance to water companies on managing PFAS concentrations with the latest version issued in March 2025. It states that the maximum recommended level for a total concentration of 48 different PFAS is 0.1 ug/l, which is also the proposal for a new regulatory standard outlined in the recommendations of the Water Quality Standards Advisory Panel. 

In our laboratory, we monitor PFAS in drinking water to UKAS (United Kingdom Accreditation Service) accredited standards.  Since this began in 2023, we have carried out over 7164 tests. 

To date, we have not identified any point source pollution of our sources, and any low-level detections are associated with the ever present and persistent nature of these compounds.  We continue to monitor all our sources so that we can respond to any future changes in regulatory expectations or guidance.

The DWI’s guidance outlines actions required depending upon sampling results and these are split across three Tiers.

Tier 1: sources in this category are considered to be low risk, where monitoring is carried out quarterly. Most of our water treatment works fall into this category.

Tier 2: we carry out enhanced monitoring and either already have treatment in place to ensure that the final treated water supplied to customers is in Tier 1 or have committed through our investment plan to install additional treatment between 2025 and 2030. 

Tier 3:  these sources are considered to be the highest risk where action must be taken to ensure that the water supplied to customers is reduced to Tier 2, or below, as soon as possible, with a longer-term strategy to achieve Tier 1.  We have no sites in this Tier. 

We have ensured PFAS is included in our drinking water risk assessments and included in our Drinking Water Safety Plan. This assesses where potential sources of PFAS could pose a risk to our catchments and raw water sources and what actions we can take in response. We will continue to participate in the latest research to improve our understanding of treatment options for PFAS in drinking water.