For most of the last century, clean water meant water free of pathogens and visible pollution. Chlorine, sand filters and settling tanks did that job well. Today the challenge is different. Utilities are being asked to remove contaminants measured in parts per trillion, chemicals that persist for decades and that conventional treatment was never designed to catch. The most prominent are PFAS, the so-called forever chemicals, but they sit within a wider group of emerging contaminants that includes pharmaceuticals, industrial micropollutants and microplastics.
This article looks at how regulation is evolving in 2026, which treatment technologies are being deployed at scale, and what the shift means for suppliers and investors.
Regulation Is Changing Shape, Not Disappearing
In the United States, the 2024 national drinking water rule set enforceable limits for six PFAS. In May 2026, the Environmental Protection Agency proposed significant changes. It would keep the limits of four parts per trillion for the two best-known compounds, PFOA and PFOS, but allow utilities that meet certain criteria to extend their compliance deadline from 2029 to 2031. It also proposed rescinding the limits for the four other compounds covered by the original rule. Alongside the proposals, the agency announced nearly one billion dollars in grants to help small and disadvantaged communities address PFAS and other emerging contaminants. The public comment period closed on July 20.
For the treatment market, the key point is that the strictest limits remain in place. Utilities may have more time, but the investment is still required. Europe is moving in parallel. Under the recast Drinking Water Directive, limits for PFAS in drinking water apply across the European Union from January 2026, which is pushing utilities in member states to test, plan and invest.
Removing What Conventional Treatment Misses
PFAS are difficult to remove because they are small, stable and highly mobile in water. Three technologies dominate full-scale treatment today.
- Granular activated carbon is the most widely used option. It is well understood and effective for longer-chain PFAS, but it needs frequent media replacement, and shorter-chain compounds break through faster.
- Ion exchange resins can remove a broader range of PFAS in a smaller footprint, often with longer run times, although resin costs and disposal need careful management.
- High-pressure membranes, meaning reverse osmosis and nanofiltration, remove PFAS along with many other contaminants. They provide the most comprehensive treatment but use more energy and produce a concentrate stream that must be managed.
The choice depends on the water source, the mix of compounds present, the size of the system and the cost of disposing of spent media or concentrate. Many utilities are piloting more than one option before committing, which is one reason the extended deadline has been welcomed.
The Problem of Where PFAS Go Next
Removing PFAS from drinking water does not destroy them. They end up in spent carbon, used resin or membrane concentrate, and those residuals have to be handled safely. This has created strong interest in destruction technologies, including supercritical water oxidation, electrochemical oxidation and high-temperature processes, that can break the carbon-fluorine bond. Most are still early in commercial deployment, but they are likely to become an important part of the PFAS treatment chain as regulators look more closely at residuals.
Membranes and UV Beyond PFAS
Emerging contaminants are not only a PFAS story. Pharmaceuticals, personal care products and industrial chemicals appear in many water sources, especially where treated wastewater returns to rivers that supply drinking water.
Membrane filtration, from microfiltration and ultrafiltration through to reverse osmosis, is becoming a standard part of advanced treatment trains. Ultraviolet treatment plays a complementary role. UV disinfection inactivates pathogens without adding chemicals, and UV combined with an oxidant, known as advanced oxidation, breaks down many organic micropollutants. UV-LED systems are an emerging part of this market. They contain no mercury, switch on instantly and suit smaller and decentralized systems, although conventional mercury lamps still dominate large municipal installations.
Cost and Who Pays
The central challenge is cost. Upgrading treatment for parts-per-trillion contaminants is expensive, and the burden falls hardest on small systems with limited budgets. Public grants, revolving loan funds and settlements from PFAS manufacturers are all helping to fund projects. Operating costs matter as much as capital costs, because media replacement, energy use and residual disposal continue for the life of the plant.
This is pushing interest toward service-based models, where suppliers manage media changeouts, monitoring and disposal under long-term contracts. For technology providers, recurring service revenue may prove as valuable as the initial equipment sale.
What Buyers and Investors Should Watch
- Final regulatory decisions. The outcome of the 2026 United States proposals and any related litigation will shape the timing of utility spending.
- Short-chain performance. Technologies that handle shorter-chain PFAS effectively will be favored as monitoring becomes more detailed.
- Residuals management. Suppliers that can offer safe disposal or destruction of spent media and concentrate will have an advantage.
- Energy efficiency. Lower-energy membranes and efficient UV systems reduce operating costs and strengthen sustainability credentials.
- Small-system solutions. Compact, packaged and service-based treatment for smaller utilities is likely to be one of the fastest-growing parts of the market.
Clean water technology is entering a period where the standard is no longer simply safe water, but water free of contaminants that were barely measurable a generation ago. The timelines may shift, but the direction is clear. Utilities will need more advanced treatment, and the suppliers that combine effective removal with manageable costs and safe residual handling are best placed to meet that demand.