For years, PFAS sat on the edge of most UK site investigations. Few labs tested for them, few consultants asked about them, and few buyers knew to check. That changed in 2026.
On 3 February, Defra published the UK’s first PFAS Plan, a national framework to reduce the environmental and health impacts of these chemicals. The plan rests on three pillars: understanding PFAS sources, tackling PFAS pathways, and reducing ongoing exposure.
If you own, buy, fund, or redevelop land in the UK, PFAS now belongs in your risk register.
How widespread PFAS is in UK groundwater
The monitoring data is hard to ignore. PFAS turned up in around 80% of surface water samples, about 50% of groundwater samples, and every fish sample tested.
PFAS are a large group of synthetic fluorinated chemicals that persist in the environment. They do not break down in normal conditions. They move easily through soil into aquifers, and they travel long distances once they reach groundwater.
Typical UK sources include airfields and fire training grounds that used firefighting foam, landfills, metal plating and coating works, textile and paper finishing, and some chemical plants. Many of these sites now sit in redevelopment pipelines.
What the PFAS Plan changes for site owners
The plan sets out several near term actions. Three matter most for landowners.
More data. England will keep sampling 2,400 PFAS samples a year from freshwater, and Scotland is expanding from about 300 to 500 samples in 2026.
A risk map. By the end of 2026, the Environment Agency’s PFAS prioritisation map will be available to all public sector bodies in England. Planning authorities and regulators will use the map to flag high risk areas, which means more sites will face PFAS questions at planning stage.
Tighter rules on sources. PFOA containing firefighting foams have been banned from use since July 2025, and the UK government is expected to consult on a statutory PFAS limit for drinking water during 2026.
Today there are no statutory limits for PFAS in surface water or groundwater. Do not read that as a free pass. The direction of travel is clear, and regulators already ask for PFAS data on sensitive sites.
The Environment Agency is building a consistent approach
Regulators are preparing for more PFAS cases. The Environment Agency’s National Groundwater Team noted that industry now carries out detailed quantitative risk assessments with a PFAS focus more often, and that a consistent review approach is needed. The agency commissioned work to support guidance on how to undertake a DQRA for PFAS contaminated groundwater.
For you, that means future submissions will face a defined standard. Reports based on thin data or generic assumptions will struggle.
Where hydrogeological consulting fit
PFAS risk is a groundwater problem first. Good hydrogeological consulting answer the questions regulators, lenders, and buyers will ask.
Desk study. Site history, past uses, foam use records, neighbouring sources, aquifer designation, and nearby abstractions or protected sites.
Targeted investigation. Boreholes and monitoring wells placed to intercept likely pathways, with sampling under PFAS specific protocols. PFAS appear in many everyday materials, so field teams must avoid cross contamination from clothing, equipment, and sample containers.
Conceptual site model. A clear picture of source, pathway, and receptor. This model drives every later decision.
Detailed quantitative risk assessment. Modelling of how PFAS move through the aquifer and what concentrations could reach a receptor such as a borehole, river, or spring.
Monitoring plan. Long term data to show whether conditions are stable, improving, or worsening.
Options for contaminated groundwater treatment
If the risk assessment shows a problem, contaminated groundwater treatment options for PFAS include several proven methods.
Pump and treat with granular activated carbon. Groundwater is extracted, passed through carbon filters, and discharged or reused. Spent carbon then needs proper handling.
Ion exchange resins. Often more effective than carbon for short chain PFAS, which move faster and adsorb less.
In situ barriers. Permeable reactive barriers or injected sorbents that capture PFAS as groundwater flows through.
The right option depends on concentrations, aquifer properties, receptor sensitivity, and budget. A feasibility study with site data should drive the choice.
When soil remediation are needed
PFAS often sit in the soil above the water table, especially near former foam use areas. That soil keeps feeding the groundwater plume for years. Treating groundwater without addressing the source rarely works long term.
Common soil remediation for PFAS include excavation and disposal, stabilisation with sorbent additives to lock PFAS in place, and soil washing to separate fine particles where PFAS concentrate. Each option carries different costs, waste implications, and regulatory steps under the Environment Agency’s Land Contamination Risk Management guidance.
Questions to ask before you appoint a consultant
Do you sample to PFAS specific protocols and use accredited labs?
Have you prepared DQRAs accepted by the Environment Agency, NRW, or SEPA?
Can you design and cost both groundwater treatment and soil remediation options?
How will you phase work to protect the development programme?
What to do now
Check site history for foam use, fire training, plating, landfilling, or textile finishing. Add PFAS to the analytical suite for any new ground investigation on higher risk sites. Review older reports and ask whether PFAS were tested. If they were not, plan a targeted round of sampling before the PFAS prioritisation map puts your site on a regulator’s list.
Early data costs far less than a late surprise at planning, sale, or refinancing.