PFAS in Drinking Water: New UK Limits and What Water Companies Must Do

PFASDWIDrinking Water QualityWater TreatmentAMP8

What Are PFAS and Why Do They Matter?

PFAS — per- and polyfluoroalkyl substances — are a group of over 4,000 man-made chemicals used in everything from non-stick cookware and firefighting foam to waterproof clothing and food packaging. They don't break down naturally, which is why they've earned the name "forever chemicals."

In drinking water, PFAS are a significant and growing concern. Research links long-term exposure to increased cancer risk, immune system disruption, thyroid problems and developmental effects in children. The challenge for UK water companies is that PFAS contaminate source waters — rivers, reservoirs and groundwater — and standard treatment processes were not designed to remove them.

The DWI's New Limits — August 2024

In August 2024 the Drinking Water Inspectorate (DWI) introduced significantly tightened PFAS limits for England and Wales, aligning with the direction of travel in EU and US regulation. The new parametric values are substantially lower than previous guidance, meaning water sources that were previously compliant may now require treatment.

The DWI's position is clear — water companies must demonstrate a credible programme for achieving compliance. Where they cannot, the DWI is issuing statutory improvement notices that require investment plans and delivery milestones.

What Treatment Technologies Are Being Deployed?

There are three primary treatment technologies currently being deployed or evaluated by UK water companies for PFAS removal:

Granular Activated Carbon (GAC)

GAC is currently the most widely used PFAS treatment technology in the UK. Carbon granules adsorb PFAS compounds as water passes through a filter bed. The key operational cost is spent carbon replacement or reactivation — which creates a significant and recurring supply chain opportunity for carbon suppliers and reactivation service providers.

Puragen Ltd won a five-year multi-site PFAS treatment contract with a UK water utility in March 2025, competing against more established rivals specifically on the strength of their UK-based carbon reactivation facility. This is exactly the kind of specialist supply chain opportunity that Water Industry Hub exists to surface.

Powdered Activated Carbon (PAC)

PAC is dosed directly into the treatment process and is particularly effective for episodic PFAS events or as a complementary treatment alongside GAC. Scottish Water awarded a £7.1m, eight-year PAC supply framework to Charles Tennant & Company Ltd in February 2026 — a contract directly driven by PFAS compliance requirements.

Ion Exchange (IX)

Ion exchange resins are highly selective for PFAS and can achieve very low effluent concentrations. They are more expensive than GAC per unit volume but may be preferred where space is constrained or where the highest removal efficiency is required. Puraffinity Ltd, a London-based Imperial College spinout that raised £17m in Series A funding, has developed selective PFAS adsorbent materials that offer a next-generation alternative.

High-Pressure Membranes (Nanofiltration / Reverse Osmosis)

Nanofiltration and reverse osmosis can achieve high PFAS rejection rates but generate a reject stream that requires further treatment. They are typically used where other technologies are insufficient or as a final polishing step.

The Water Company Procurement Response

PFAS treatment is now embedded in AMP8 business plans across the sector. Water companies are procuring across several categories simultaneously:

Procurement Category	What's Being Bought	Frequency
Capital — Treatment Plant	GAC contactors, IX vessels, membrane systems, civil works	One-off / AMP8
Carbon Supply	Virgin GAC, PAC supply contracts	Annual / framework
Carbon Reactivation	Spent carbon collection, reactivation, return	Ongoing / 5-year+
Analytical Services	PFAS laboratory testing (UKAS accredited)	Routine / compliance
Consultancy	Treatment process design, options appraisal	Project-based
Emergency Treatment	Mobile GAC and IX hire units	As required

What This Means for Suppliers

The PFAS treatment market in UK water is not a single large contract — it is hundreds of smaller procurement events spread across all fourteen affected water companies over the next five to ten years. Every water treatment works serving a PFAS-affected catchment needs a solution. The supply chain requirements range from specialist technology providers through to carbon logistics, laboratory services, civil engineering contractors and MEICA specialists.

Companies active in any of these categories should be monitoring Find a Tender and the individual water company procurement portals closely. The procurement volume in this category will be substantial throughout AMP8 and into AMP9.

The Regulatory Outlook

The DWI's direction of travel is clear — limits will tighten further over time, consistent with the trajectory in the EU's revised Drinking Water Directive and US EPA's Maximum Contaminant Levels published in 2024. Water companies that invest in treatment infrastructure now are making long-term assets that will serve compliance requirements well beyond AMP8.

The Water (Special Measures) Act 2025 and the Independent Water Commission's 88 recommendations published in July 2025 both reinforce the direction of increasing regulatory stringency on water quality. PFAS is at the top of that agenda.