UK water firms ordered to curb PFAS in drinking water affecting over six million people

BBC News reports that UK water companies face enforcement notices to address potentially harmful PFAS in drinking water sources serving over six million people. PFAS, or forever chemicals, persist in the environment and have been linked to health risks at low levels. The Drinking Water Inspectorate (DWI) requires more testing, treatment upgrades, or removal of contaminated sources, with a 0.01 ug/L threshold used to flag danger. Tests show PFOS and PFOA appearing in hundreds of samples since 2024. Water UK asserts current drinking water safety but calls for a ban on PFAS to prevent accumulation. The process, ongoing since 2021, highlights the technical and financial challenges for water companies as policy discussions advance in England and Wales.

Overview and scope

Water companies in the United Kingdom have been served enforcement notices by the Drinking Water Inspectorate (DWI) over elevated PFAS levels in drinking water sources. These notices affect sources that supply water to households and other drinking-water sources, with a minimum reach of around six million people. Forever chemicals, or PFAS, comprise thousands of substances used in everyday products and are persistent in the environment. The BBC analysis of enforcement documents shows that when a test result breaches the 0.01 ug/L threshold, the DWI requires action such as increased testing, treatment upgrades, or even removing a water source from supply. The investigation notes that PFOS and PFOA were found in more than 350 tests among 2024 results obtained via Freedom of Information requests, underscoring the prevalence of PFAS in some supply networks.

What PFAS are and why they matter

PFAS have been widely used since the 1940s, found in cookware, medical devices, textiles and firefighting foams. They persist in the environment—entering drinking water through product wash-off, storm runoff, and industrial releases. Health concerns are rising for a subset of PFAS compounds, with the World Health Organization labeling PFOA as carcinogenic and PFOS as possibly carcinogenic. Although regulators insist that water remains safe, the presence of PFAS in source water continues to trigger vigilance and responsive treatment strategies.

Enforcement and industry response

The DWI says that sanctions trigger intensified testing, treatment modifications, or source removal, with several years often passing before sanctions are lifted. Water UK maintains that drinking water quality in the UK is among the best globally, but the group has called for stronger controls, including banning PFAS to prevent accumulation. In the policy arena, independent analyses and government reviews have pushed for stricter treatment requirements and tighter limits, potentially to be enshrined in law rather than guidance alone. A government white paper is anticipated to address the Drinking Water Inspectorate and related regulatory changes.

“This £70m we are spending each and every year should be paid for by the chemical companies, it is really unfair for people through their water bills to have this added on top,” - David Henderson, Water UK Chief Executive.

Technical challenges and cost considerations

Experts acknowledge that removing PFAS is technically challenging with conventional treatment. Technologies such as nanofiltration can reduce PFAS levels but come with high capital costs and substantial energy demands. As water companies navigate elevated monitoring and more stringent requirements, debate continues over how to fund these upgrades and whether broader regulatory tightening is warranted. An independent review commissioned by the government has already signaled the need for stricter treatment requirements to protect public health and the environment. The BBC notes that the government is preparing a white paper in response to that review, which could reshape PFAS regulation and the responsibilities of the DWI.

“There are technologies such as nanofiltration occasionally deployed by the water industry which could be used more widely, but these came with high costs and huge energy demands,” - Prof Peter Jarvis, Cranfield University.

Outlook and unanswered questions

While the DWI emphasizes that public drinking water is safe under current safeguards, charities and chemistry researchers argue for legally binding limits to ensure accountability. The ongoing monitoring program and enforcement activity reflect a broader shift toward tighter PFAS controls in the UK, with policymakers weighing health protections, infrastructure investments, and industry costs. For consumers, the central takeaway is that PFAS management remains a long-term priority for water suppliers, with potential changes on the horizon as England and Wales refine their regulatory framework.