PFAS contamination is no longer a problem limited to specialist laboratories or industrial sites. These persistent chemicals have been detected in rivers, groundwater, drinking-water sources, soils and even household products. For water companies, businesses, local authorities and private well owners, the practical question is increasingly clear: what should we do when PFAS are suspected or detected?
A robust PFAS plan does not begin with buying a filter. It begins with understanding the contamination, identifying who may be exposed, and choosing controls that can be tested and maintained over time. The most effective response combines monitoring, source control, treatment, communication and regular review.
What a PFAS management plan needs to achieve
PFAS, or per- and polyfluoroalkyl substances, are a large family of synthetic chemicals used for their resistance to heat, oil, water and stains. Some were used in firefighting foams, metal plating, textiles, paper coatings, non-stick products and industrial processes. Their carbon-fluorine bonds are exceptionally strong, which is why many PFAS persist in the environment for years or decades.
A practical plan should answer five basic questions:
- Which PFAS are present, and at what concentrations?
- Where did the contamination come from?
- Who or what could be exposed?
- Which treatment technology is appropriate for the water chemistry?
- How will performance, waste and changing regulations be managed?
This structure is important because PFAS contamination rarely behaves like a simple spill. It can move through groundwater, remain in sediments, and pass through conventional water-treatment processes. A single sample can also give a misleading impression if sampling locations, timing or laboratory methods are poorly selected.
Start with a site and source assessment
The first step is to create a clear picture of the site. Review current and historical activities, not just what is happening today. Former industrial operations, airports, military facilities, fire-training areas, landfills, wastewater discharges and sites where firefighting foam was stored may all require attention.
Useful information includes:
- Historical land use, permits and chemical inventories.
- Locations where aqueous film-forming foam, or AFFF, may have been used.
- Industrial drains, lagoons, storage tanks and waste-disposal areas.
- Groundwater flow direction and nearby surface-water bodies.
- Abstraction points, private wells and drinking-water intakes.
- Existing data from regulators, water companies or previous investigations.
PFAS can travel beyond the original release area. A contaminated source zone may therefore affect a downstream river or a groundwater abstraction point several kilometres away. Mapping the hydrology is as important as mapping the suspected source.
Where the source is uncertain, a phased investigation is usually more efficient than immediately drilling numerous monitoring wells. Begin with a screening assessment, then use the results to refine the sampling programme. This avoids spending heavily on data that do not help answer a management question.
Build a sampling programme that can withstand scrutiny
PFAS sampling is not simply a matter of filling a bottle. These compounds can be present at very low concentrations, and contamination can be introduced by sampling equipment, waterproof clothing, cosmetics, packaging or certain tubing materials.
A credible programme should be designed with an accredited laboratory and, where relevant, an environmental consultant or regulator. The plan should specify sampling points, frequency, target compounds, analytical methods, quality controls and reporting limits.
Sampling teams commonly use field blanks, equipment blanks, trip blanks and duplicate samples to identify contamination or variability. Chain-of-custody records should document who collected, handled and analysed each sample.
It is also essential to define which PFAS will be tested. A narrow list may miss compounds that are important at a particular site, while a broader analytical suite can provide a more useful fingerprint of the source. Some laboratories also report precursor compounds or use total organic fluorine and extractable organic fluorine techniques as additional lines of evidence. These methods are not interchangeable with targeted PFAS analysis, but they can help identify contamination that targeted testing does not capture.
Results should be interpreted alongside the applicable standard or guideline. Limits differ between jurisdictions and may change as scientific evidence develops. In the UK, organisations should monitor guidance from the Drinking Water Inspectorate, the Environment Agency, UK Health Security Agency and relevant devolved administrations. A result that is below one regulatory threshold is not automatically “safe” for every use or every jurisdiction.
Assess exposure and prioritise risks
Risk assessment should focus on how people and ecosystems may come into contact with PFAS. Drinking water is often the main concern, but it is not the only pathway. Food grown with contaminated irrigation water, fish from affected rivers, accidental ingestion of soil and exposure during industrial work may also be relevant.
For drinking-water supplies, consider:
- The concentration and composition of PFAS detected.
- How often people drink or use the water.
- The number of people served by the supply.
- Whether infants, pregnant people or other sensitive groups may be exposed.
- Whether the water is used for cooking, food preparation or only non-potable purposes.
- Whether contamination is stable, increasing or declining.
PFAS are often discussed as a group because many individual substances share characteristics such as persistence and mobility. However, toxicity and environmental behaviour vary between compounds. Short-chain PFAS may move more readily through water, while some long-chain substances may bind more strongly to sediments or biological tissues. A management plan should therefore avoid treating every PFAS result as identical.
When a drinking-water result raises concern, communication should be prompt and specific. People need to know what was detected, what it means for drinking and cooking, what alternative water is available, and when further information will be provided. Vague reassurance can damage trust; so can alarming language unsupported by the evidence.
Control the source wherever possible
Removing PFAS from water can be technically difficult and expensive. Preventing further releases is usually the most sustainable control.
Source-control measures may include replacing PFAS-containing materials, improving chemical storage, inspecting drainage systems, containing contaminated runoff and safely managing legacy firefighting foams. Facilities that use firefighting agents should maintain an inventory, prevent accidental discharge and ensure that emergency response procedures account for PFAS risks.
Industrial sites should examine processes where PFAS may be used as surfactants, processing aids or performance additives. Suppliers should be asked for current composition information rather than relying solely on old safety data sheets. “PFOA-free” or “PFOS-free” does not necessarily mean PFAS-free: a product may contain alternative PFAS compounds.
Waste management is another critical point. Activated carbon, filter media, contaminated soil and concentrated treatment residues can contain PFAS even when the treated water meets its target. These materials must be handled, transported and disposed of under applicable hazardous-waste and environmental rules.
Choose treatment based on the water, not the marketing
No single treatment system is ideal for every PFAS problem. The correct choice depends on the PFAS profile, concentration, flow rate, competing contaminants, water chemistry, available space, operating budget and waste-disposal route.
Granular activated carbon
Granular activated carbon, or GAC, is widely used for PFAS removal. It can be effective, particularly for longer-chain compounds, and is available at community and industrial scale. Performance depends on empty-bed contact time, carbon type, organic matter, competing substances and the concentration of PFAS entering the system.
GAC is not a “fit and forget” solution. Breakthrough can occur when the media becomes exhausted. Monitoring should be carried out at the inlet and outlet, with replacement schedules based on evidence rather than assumptions. Spent carbon must also be regenerated or disposed of safely.
Ion exchange
Ion-exchange resins can remove many PFAS efficiently and may require less space than GAC. They can be particularly useful where high flow rates or stringent targets apply. However, resin selection matters, and organic matter or other ions in the water may affect performance.
Like activated carbon, ion exchange transfers PFAS into a concentrated waste stream or spent medium. Disposal and regeneration arrangements should be agreed before installation.
Reverse osmosis and nanofiltration
Membrane processes, including reverse osmosis, can achieve high removal across a broad range of PFAS. They are often considered for small drinking-water systems, point-of-use devices or situations requiring very low concentrations.
The trade-offs include energy use, membrane fouling, maintenance and the production of a concentrated reject stream. Reverse osmosis does not destroy PFAS; it separates them from the treated water. That concentrate still requires controlled management.
Emerging destruction technologies
Research is progressing on technologies designed to destroy PFAS rather than capture them. These include electrochemical treatment, supercritical water oxidation, plasma processes and advanced photochemical methods. Some are promising, but full-scale performance, energy demand, by-products and regulatory acceptance must be assessed carefully.
Be cautious with claims that a device “eliminates all PFAS” without independent performance data. Ask for test conditions, the compounds tested, detection limits, operating capacity and evidence from water that resembles the site’s own supply.
Use point-of-use treatment carefully
Under-sink reverse-osmosis units and certified activated-carbon filters can reduce PFAS in individual homes or small facilities. They may provide a useful short-term measure while a wider investigation is under way. However, household filters require correct installation, regular cartridge replacement and confirmation that the product has been tested for the relevant PFAS claims.
A filter that removes chlorine or improves taste is not automatically effective against PFAS. Consumers should look for independent certification or transparent laboratory data, and should avoid devices that provide only general statements such as “advanced purification.” Poorly maintained filters can also become a source of microbial growth or lose effectiveness without the user realising it.
Monitor, document and review
A PFAS plan should remain active after treatment begins. Create a monitoring schedule covering raw water, treated water, distribution points and, where appropriate, nearby groundwater or surface water. Sampling frequency should reflect risk, seasonal changes, treatment performance and regulatory requirements.
Keep records of:
- Laboratory results and detection limits.
- Filter or resin installation and replacement dates.
- Flow rates, pressure changes and operating conditions.
- Waste volumes and disposal documentation.
- Complaints, incidents and communication with affected users.
- Changes in legislation, guidance and site activities.
Set trigger levels before results arrive. For example, a rising trend at the treatment outlet may require immediate resampling, media replacement or a temporary change in water use. Pre-agreed actions reduce delays during an incident and make responsibilities clear.
Build trust through transparent communication
PFAS contamination can cause understandable concern because the chemicals are persistent and invisible. Effective communication should explain uncertainty without hiding behind technical language. Share what is known, what is not yet known, what action is being taken and when the next update will be available.
Useful communication avoids two extremes: treating every detection as an emergency, or suggesting that a result is unimportant simply because it is low. A clear factsheet, public monitoring dashboard or regular community briefing can help residents understand trends and treatment performance.
For organisations, the strongest PFAS plan is not a one-time technical report. It is a living system that links scientific evidence to practical decisions: stop releases, measure carefully, protect people, select treatment realistically and verify results over time. PFAS may be persistent, but poor monitoring and weak planning do not have to be.