PFAS in UK Drinking Water – What Every Household Should Know

This guide was written by Keith, a mechanical engineer with over 20 years of hands-on experience working with reverse osmosis and water filtration systems.

A clear, calm guide by FilterAuthority.co.uk

Written by Keith
Updated:
📖 20 min read

In January 2025, The Guardian published an investigation that made headlines across the UK: "Drinking water sources in England polluted with forever chemicals." The analysis revealed that 199 untreated water samples from major suppliers—Thames Water, Anglian Water, Affinity Water, Southern Water—exceeded safe PFAS thresholds.

My inbox filled with worried questions: "Is my tap water safe?" "Should I buy a filter?" "Why isn't anyone talking about this?"

Here's what I told them—and what I'm telling you now: UK tap water is treated and meets current standards, but those standards are 25 times weaker than the US's proposed limits. Many families are deciding they want an extra layer of protection, especially for young children.

What This Guide Covers

This guide explains, in plain English, what PFAS are, what the Guardian investigation found, how UK standards compare to the US and Scotland, and what you can realistically do at home to reduce your exposure.

No scare tactics.

No complicated chemistry.

Just clarity—and practical options.

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What Are PFAS? (Simple Explanation)

PFAS (Per- and Polyfluoroalkyl Substances) are man-made chemicals used since the 1940s in:

Non-stick cookware
Waterproof clothing
Firefighting foam
Food packaging
Electronics
Household goods

They're known as "forever chemicals" because they don't break down easily — either in the environment or in the human body.

Over time, PFAS can build up in:

  • Water
  • Soil
  • Wildlife
  • People

Research suggests long-term exposure may affect:

Hormones
Cholesterol
Immune function
Pregnancy
Child development

This guide helps UK households understand what's happening and what options exist.

The Guardian Investigation (January 2025): What Was Found

🚨 Key Findings

The Guardian and Watershed Investigations analyzed sampling data from water companies, the Environment Agency, and the Drinking Water Inspectorate (DWI). Here's what they found:

  • 199 untreated drinking water samples exceeded 100 ng/L (the DWI's safe threshold)
  • Anglian Water: 137 samples above threshold (supplies Bedfordshire, Cambridgeshire, Essex, Lincolnshire, Norfolk, Suffolk)
  • Affinity Water: 54 samples above threshold (supplies parts of London, Hertfordshire, Surrey, Berkshire)
  • Thames Water, Southern Water, South East Water, Wessex Water: At least one sample above threshold

📍 Where PFAS Contamination Was Found

RAF Bases & Airports (Firefighting Foam)

  • RAF Mildenhall (West Suffolk): 1,670 ng/L PFOS detected (16x the safe limit!)
  • RAF Marham (Norfolk): 211 ng/L PFOS
  • Duxford airfield (Cambridgeshire): High PFAS levels confirmed as source of contamination for South Cambridgeshire water supply
  • 17 airports in England: Elevated PFAS in ground and surface water

Industrial Areas

  • Ulceby & Barrow (Lincolnshire): Near oil refineries and heavy industry, Humberside airport. PFOS and PFOA (banned carcinogens) found above threshold
  • Halstead (Essex): Anglian Water's Parsonage Street works flagged by DWI

Affinity Water High-Risk Areas

  • Letchworth, Baldock, Wheathampstead: High PFOS concentrations
  • Denham: Source taken out of service entirely due to contamination

⚠️ What Water Companies Do About It

When PFAS are detected above safe limits in untreated water sources, companies:

  • Blend contaminated water with clean water to dilute PFAS levels below the threshold
  • Install treatment systems (activated carbon, RO) at treatment works
  • Shut down highly contaminated sources (like Affinity Water did at Denham)
  • Receive DWI notices requiring preventive action (United Utilities, South West Water, Severn Trent, Wessex Water, South Staffordshire all received notices)

Bottom line: The water reaching your tap is treated and meets current UK standards. But those standards are much weaker than other countries—which is why many families want their own filter.

📰 Source:

The Guardian: "Revealed: drinking water sources in England polluted with forever chemicals" (January 16, 2025)

Environment Agency Update (July 2025): PFAS in English Rivers, Lakes & Fish

🚨 New Findings: 94% of English Waters Exceed Proposed Safety Limits

In July 2025, analysis by Wildlife and Countryside Link and the Rivers Trust revealed alarming PFAS contamination across England's water bodies:

  • 110 of 117 water bodies tested (94%) would fail the EU's proposed new safety standard
  • 85% contain PFAS levels at least 5x higher than proposed limits
  • PFOS in fish averaged 322x higher than planned wildlife limits
  • Just one portion of freshwater fish per month would exceed safe annual PFOS consumption for humans

📊 What the Numbers Mean

The Proposed EU Standard

The EU has proposed limiting the combined toxicity of 24 PFAS to 4.4 nanograms per litre, calculated as "PFOA-equivalents" — a method that weights each substance by its toxicity relative to PFOA, a particularly hazardous carcinogen now banned.

The EU is also planning to regulate approximately 10,000 PFAS as one class because there are too many to assess individually, and none break down in the environment.

UK vs EU Approach

The UK has no plans to follow the EU's group-based PFAS restrictions. Environmental groups are urging the government to align with EU standards and ban PFAS in food packaging, clothing, cosmetics, toys, and firefighting foams — following examples from Denmark, France, and the EU.

🏥 Health Concerns Highlighted

Health and environmental charities have joined forces to call for urgent action:

  • Breast Cancer UK: "Evidence points to the potential for some PFAS to be related to health issues, including increasing breast cancer risk"
  • Wildlife and Countryside Link: "PFAS are linked to an explosion of impacts for wildlife and public health, from cancers to immune issues"
  • 59 PFAS experts urged the government in 2024 to regulate all PFAS as a single class, warning their extreme persistence poses a serious environmental threat

🏛️ Government Response

The Environment Agency says it is running a "multi-year programme" to improve understanding of PFAS pollution sources. DEFRA states the government is "committed to protecting human health and the environment" and is "working at pace" to assess PFAS levels.

Translation: Studies are ongoing, but no new regulations are imminent. For now, household filtration remains the most practical option for families wanting to reduce exposure.

📰 Source:

The Guardian: "Toxic PFAS above proposed safety limits in almost all English waters tested" (July 11, 2025). Analysis by Wildlife and Countryside Link and the Rivers Trust using Environment Agency data.

Do UK Water Companies Test for PFAS?

It depends where you live.

Here is a simple breakdown:

England

Some water companies test regularly, others test selectively.

Wales

Welsh Water has conducted PFAS tests across various regions, though results vary.

Northern Ireland

NI Water has carried out PFAS sampling but updates are not always frequent.

Scotland

Scottish Water has historically done limited PFAS testing. This does not mean PFAS are absent — only that fewer tests are published.

Are PFAS Found in UK Tap Water?

Short answer: In many areas, yes — at varying levels.

Not everywhere, but enough for reasonable concern.

When PFAS are detected, suppliers may:

  • Blend water
  • Fluctuate abstraction sources
  • Adjust treatment
  • Publish further sampling

But there is no nationwide PFAS removal system across the UK.

This is why many households prefer home filtration for peace of mind.

UK vs US vs Scotland: How PFAS Standards Compare

Here's where it gets interesting—and why many UK families are choosing to install their own filters rather than wait for government action.

📋 PFAS Limits Comparison

RegionPFAS LimitStatus
United States4 ng/L (proposed)Strictest
Scotland & Northern Ireland60 µg/L (EU standard)Legally binding (since 2022)
England & Wales80 µg/L (proposed)Voluntary guidance only
England & Wales (current)100 ng/L (individual PFAS)25x weaker than US

⚠️ The UK Standards Gap

UK's current standard: 100 ng/L for individual PFAS in treated drinking water.

US proposed standard: 4 ng/L — that's 25 times stricter than the UK.

Dr Shubhi Sharma from Chem Trust: "The standards currently in place in the UK are outdated and not protective enough."

🏴󠁧󠁢󠁳󠁣󠁴󠁿 Scotland Ahead of England

Scotland & Northern Ireland: Already embedded EU Drinking Water Directive standards (2022) — legally binding limits.

England & Wales: Still using standards from 1998, relying on voluntary guidance that's not legally enforceable. If you're in a hard water area like London, Birmingham, or Bristol, you might want extra protection for your family.

A 2025 industry report headline: "Scotland and Northern Ireland may be ready for 2026, but England and Wales face unresolved questions: Will new limits for lead, PFAS and HAAs be enacted in time? Or will regulators rely on voluntary guidance?"

✅ My Take: Why This Matters

If you live in England or Wales, you're getting weaker PFAS protection than Scotland—and far weaker than the US.

UK tap water is treated and meets current standards. But when those standards are 25x weaker than the US, and when England/Wales are relying on "voluntary guidance" while Scotland has legally binding limits, many families are deciding: "I'll install my own filter and not wait for the government to catch up."

That's not fear-mongering—that's a reasonable response to a regulatory gap that's been acknowledged by scientists, water companies, and industry bodies.

📰 Sources:

  • • Envirotech Online: "Is the UK ready for the Drinking Water Directive to come into force?" (October 2025)
  • • Chem Trust: "Regulating PFAS 'Forever Chemicals' in the UK" (July 2025)
  • • The Guardian: PFAS investigation (January 2025)

Which Water Filters Remove PFAS?

Two technologies consistently help:

1. Activated Carbon Block Filters

These adsorb PFAS onto the carbon surface.

Good for:

  • Everyday use
  • Renters
  • Under-sink and countertop systems
  • Improving taste + reducing chlorine

Look for:

  • Solid carbon block (not loose carbon)
  • Independent test data where available
  • Mention of PFAS or short-chain PFAS reduction

2. Reverse Osmosis (RO)

RO membranes physically block PFAS molecules.

Good for:

  • Baby formula
  • Health-conscious households
  • High-PFAS concern areas
  • Strongest overall reduction

RO is considered the most effective option for PFAS removal.

Do Brita or Basic Jugs Remove PFAS?

Most standard jug filters do not meaningfully reduce PFAS.

Only advanced carbon block filters or RO systems show reliable performance.

Should UK Families Be Worried?

A calm, realistic answer:

No need for panic — but awareness is wise.

UK PFAS risk is:

  • Low to moderate in many areas
  • Higher near industrial or airport zones
  • Harder to estimate where testing is limited (e.g., parts of Scotland)

Many families choose filtration simply because:

It improves taste
It reduces chlorine and microplastics
It offers peace of mind
It protects babies and vulnerable users
It's cheaper than bottled water

How to Check PFAS in YOUR Area

Two simple options:

1. Check your water supplier's annual quality report

Search for:

"PFAS", "PFOS", or "PFOA"

2. Use our upcoming Postcode Water Checker

This will identify:

  • Your water supplier
  • Hardness
  • PFAS testing notes (where available)
  • Likely risk factors

Or simply:

Best Home Options for Reducing PFAS (Based on Your Needs)

Best All-Round Option

Under-sink carbon block system

Affordable, simple, reliable PFAS reduction.

Highest Protection

Reverse Osmosis (RO) with remineralisation

Ideal for baby bottles, health concerns, or high-PFAS areas.

Best Budget Option

Countertop carbon block filter

Not as strong as RO, but good everyday PFAS reduction.

PFAS Questions People Often Ask

Is PFAS in the UK water supply legal?

There are currently no statutory standards for PFAS in drinking water in England and Wales, nor is there a World Health Organisation guideline value. The Drinking Water Inspectorate (DWI) has taken a precautionary approach and produced tiered guideline values for water companies to adhere to.

Read DWI's Official PFAS Guidance →

Do all UK water suppliers test for PFAS?

No — testing varies by region.

Is PFAS harmful for babies?

Studies suggest PFAS exposure may affect development. Many parents choose RO for formula preparation.

Does boiling water remove PFAS?

No. PFAS are heat-stable.

Can shower filters remove PFAS?

No — PFAS reduction requires drinking-water filtration (carbon or RO).

About the Author

Keith is a trained mechanical engineer with over 20 years of hands-on experience working with reverse osmosis (RO) and water filtration systems.

At FilterAuthority, he translates technical filtration knowledge into clear, practical guidance for UK households.

Conclusion — Your Best Next Step

PFAS in UK drinking water isn't a reason to panic, but it is a reason to be informed.

Filtering your water at home:

Reduces PFAS
Improves taste
Removes microplastics
Reduces chlorine
Supports peace of mind

If you're not sure which system suits your home, try:

About Keith

Mechanical engineer with 20+ years of water filtration experience

Keith has spent over two decades working with reverse osmosis and water filtration systems, helping UK families make informed decisions about water quality. His engineering background and hands-on experience with PFAS research, Guardian investigations, and UK vs US standards provide the technical foundation for Filter Authority's evidence-based, no-nonsense guidance.

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