As PFAS levels raise concern in UK water, new monitoring tools and advanced treatments offer hope. The question is whether regulators will act fast enough
PFAS “forever chemicals” are widespread in UK surface and groundwater, entering rivers and aquifers via industrial discharges, firefighting foams, and wastewater plants that cannot fully remove them. Because PFAS persist and build up in catchments, utilities increasingly rely on proven treatments such as granular activated carbon, ion exchange for low-level targets, and reverse osmosis for complex mixtures. Risk-based monitoring led by the DWI is expanding, with clearer reporting and hotspot prioritisation.
What are PFAS, and why does UK water matter?
PFAS—per- and polyfluoroalkyl substances— is a vast family of thousands of synthetic “forever chemicals” that resist environmental breakdown and can remain in the human body over time. Their durability makes them a long-term concern for public health and environmental management, especially when they reach drinking water systems intended to supply drinking water safely.
UK regulators are moving toward clearer oversight, including guidance from the Drinking Water Inspectorate (DWI) to improve detection and management. The challenge is both technical and financial: many conventional water treatment methods were not designed to capture these chemicals. As seen in approaches promoted by the Environmental Protection Agency (EPA) and others, targeted filtration and exchange technologies are increasingly central to reducing exposure and compliance costs.
Where does PFAS enter UK water sources?
Where, then, do PFAS infiltrate the UK’s rivers, reservoirs, and aquifers? Evidence points first to industrial discharges, where manufacturing effluent and the use of PFAS-containing products introduce persistent chemicals into nearby water sources. A second major entry route is firefighting foams used at airports and military bases. Wastewater treatment plants also act as a continuing pathway. PFAS from homes and businesses enter sewers, yet conventional treatment often fails to remove them, allowing releases into receiving rivers and downstream abstractions.
Monitoring underscores the extent of this presence: around 80% of UK surface water samples and 50% of groundwater samples have tested positive for PFAS. Their detection in all tested fish further indicates accumulation within aquatic ecosystems connected to these water sources across the UK.
How does PFAS travel from source to tap?
Once PFAS enter rivers, reservoirs, and aquifers from industrial discharges, firefighting foams, or wastewater effluent, they can be carried onward through leaching into groundwater and runoff into surface waters that feed drinking-water abstractions. Because PFAS resist biodegradation, they persist for long periods, moving with water flow and gradually accumulating in catchments and aquifers. From there, the compounds can pass into raw-water intakes and remain through conventional clarification and disinfection steps. Many common processes are not designed to capture these highly stable chemicals, so concentrations may be only weakly reduced without targeted treatment. Where sources are affected, utilities may need specialised treatment and source-management actions to limit transfer from environment to tap.
How is PFAS monitored in UK drinking water?
How are PFAS tracked once they enter the drinking-water system? In the UK, the DWI oversees surveillance through water company sampling and reporting, designed to quantify PFAS levels and flag emerging risks in drinking water. New DWI guidance introduces a risk-based three-tier system, helping utilities prioritise where and how often to test, and how to interpret detections.
Companies must also measure 6:2 fluorotelomer sulfonamide alkylbetaine (FTAB), expanding the list of routinely checked substances. Utilities are required to notify the DWI of unidentified PFAS detected at levels below 0.01 µg/l, to support broader intelligence on precursor chemicals and analytical gaps.
Beyond treated supplies, UK monitoring programmes collect data from groundwater, surface water, and wastewater sites to map sources and pathways. Regulatory frameworks may be updated under the Environment Act 2021, aligning practice with evolving science and approaches used by an environmental protection agency (EPA).
How does granular activated carbon (GAC) remove PFAS?
Tracking PFAS through UK drinking-water networks helps utilities decide when monitoring must be matched with treatment. Granular activated carbon is widely used to remove PFAS because its porous structure and very large internal surface area provide numerous adsorption sites. As water passes through a GAC bed, hydrophobic PFAS compounds preferentially cling to carbon surfaces, lowering their dissolved concentration and improving water quality.
Performance depends on the specific PFAS compounds present, flow conditions, and the rate at which the media becomes loaded. In controlled studies, GAC has achieved removal efficiencies above 90% for some PFAS, demonstrating strong potential when properly designed and operated. Systems can be customised by selecting carbon type, bed depth, and contact time to target local contamination profiles. However, adsorption capacity is finite: as the carbon approaches saturation, breakthrough occurs and effluent concentrations rise. Regular replacement or regeneration is thus essential to sustain reliable PFAS reduction over time.
When do ion exchange or membranes work better for PFAS?
In what situations do ion exchange resins or membrane systems outperform granular activated carbon for PFAS control in UK drinking-water treatment? Ion exchange can excel when contamination is at lower concentrations and the PFAS profile is well characterised, because selective binding targets specific ions while letting much of the background chemistry pass. This often suits smaller or modular water treatment upgrades where cost control matters and rapid PFAS removal is required.
Membranes, including reverse osmosis, tend to perform better when a broader mixture of PFAS and co-contaminants must be addressed, delivering higher overall rejection. However, membranes may require pretreatment to limit fouling and maintain throughput, thereby increasing operational complexity. In some designs, Advanced Oxidation Processes can be added upstream to weaken PFAS compounds and improve downstream capture.
How is PFAS cleaned up in UK groundwater sites?
Cleaning up PFAS at UK groundwater sites typically combines source control with targeted remediation, reflecting the pollutant’s persistence and the need to protect drinking-water supplies. Investigations first map groundwater contamination, then prioritise actions where receptors are most vulnerable.
For PFAS remediation, pump-and-treat systems commonly route extracted water through activated carbon, particularly granular activated carbon, to capture long-chain compounds and reduce PFAS levels. Where site chemistry or PFAS profiles limit carbon performance, ion exchange resins provide higher capacity and can target shorter-chain substances, while advanced oxidation processes may be applied as part of treatment trains to break down precursors.
Regulators such as the Environment Agency can propose discharge limits that drive compliance-focused designs and verification sampling. Alongside established methods, innovative treatment solutions—including electrochemical treatment and nanomaterial-based filtration—are being researched to improve removal efficiency and reduce waste burdens at challenging sites.
How do you build a long-term UK PFAS risk plan?
How can a long-term UK PFAS risk plan stay credible as evidence and exposure pathways evolve? It should combine routine surveillance with transparent prioritisation. England would monitor and report on 2,400 PFAS samples each year across freshwater to track PFAS levels, identify hotspots, and evaluate whether remediation strategies are protecting the water supply.
By 2026, the Environment Agency’s PFAS GIS prioritisation map should be public, enabling local authorities and operators to align actions and funding with risk. A wider evidence base should follow: a feasibility study for PFAS monitoring in soils and a full assessment of estuarine and coastal contamination by February 2028.
Governance also matters. Collective ownership across government, industry, and the public supports consistent standards and accountability, informed by international benchmarks such as those set by the Environmental Protection Agency (EPA). This structure turns the PFAS challenge into a pathway toward a PFAS‑free market with significant economic opportunity by 2040.
