Understanding the Scope of PFAS in Urban Water Supplies
For decades, municipal water systems have been an invisible backbone of urban life—trustworthy, consistent, and safe. But an invisible threat is now forcing cities across the globe to re-evaluate their drinking water infrastructure: PFAS contamination.
PFAS, or per- and polyfluoroalkyl substances, are a class of over 4,700 synthetic chemicals widely used for their resistance to heat, water, and oil. Often referred to as “forever chemicals” due to their extreme persistence in the environment, PFAS are now found in everything from firefighting foams to non-stick cookware and industrial waste. The problem? They don’t break down, they accumulate in the body over time, and increasing scientific evidence links them to serious health risks—including cancer, liver damage, thyroid issues, and developmental effects in children.
Municipal water systems, especially in industrial regions or near military sites, have become hotspots for PFAS contamination, raising urgent questions: How do cities identify PFAS in their water? What tools are available to fix the issue? And who is taking the lead in deploying sustainable solutions?
Detecting PFAS: A Complex and Costly First Step
Before cities can treat PFAS contamination, they must first locate and quantify it—a task that has proven far from simple. Traditional water testing methods aren’t designed to detect PFAS, and advanced analytical techniques, like Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS), require both expensive equipment and highly trained personnel.
Yet, progress is being made. For example, in Michigan, the Department of Environment, Great Lakes, and Energy (EGLE) launched the Michigan PFAS Action Response Team (MPART), which includes routine statewide testing of public water supplies. This collaborative model—integrating government, science, and community reporting—has become a blueprint for other states navigating similar waters.
Filtration Solutions in Action: Beyond Activated Carbon
Historically, granular activated carbon (GAC) filters have been the go-to technology for removing organic contaminants from drinking water. But while GAC is somewhat effective against certain PFAS compounds, it falls short when tackling shorter-chain variants such as PFBS and GenX.
Cities are now turning to a mix of filtration technologies to boost efficiency:
- Ion Exchange Resins: These materials attract and bind PFAS molecules, especially shorter-chain varieties. Utilities in New Jersey, particularly in towns like Moorestown, have adopted ion exchange systems with promising results.
- Reverse Osmosis (RO): Once limited mainly to home systems, large-scale RO systems are gaining traction in municipalities like Orange County, California, where advanced purification plants treat billions of gallons annually.
- Advanced Oxidation Processes (AOPs): Combining ozone or hydrogen peroxide with UV light, AOPs are showing early promise in breaking down PFAS molecules entirely—rather than simply separating them from water.
Importantly, many cities are using these technologies in tandem. In Wilmington, North Carolina, the Sweeney Water Treatment Plant added multiple layers of defense, including both GAC and RO, targeting PFAS after the Cape Fear River was found to be heavily contaminated by Chemours’ discharges.
Case Study: Washington, D.C.’s Risk-Based Response
Washington, D.C. didn’t wait for federal enforcement to intensify its PFAS mitigation efforts. After preliminary sampling in 2020 identified hotspots near fire training and military facilities, the city implemented a “risk-based” prioritization strategy. This meant focusing resources on neighborhoods with elevated health vulnerabilities—such as areas serving schools, hospitals, and low-income housing.
Alongside targeted water system upgrades, the city launched a public awareness campaign, distributing faucet-mounted filters certified for PFAS removal to affected households. The approach highlighted a crucial but often overlooked facet of urban contamination response: equity.
Paying for Purity: The Financial Hurdle
One of the biggest challenges for municipal PFAS treatment lies not in science, but in funding. Installing full-scale filtration systems can cost tens of millions, placing strain on already tight public budgets. Smaller cities and rural utilities face an even steeper climb.
Some cities have managed to secure financial support through litigation. For instance, the City of Decatur, Alabama, reached a $98 million settlement with chemical manufacturers deemed responsible for PFAS discharges. Similar lawsuits have been filed across the U.S., and the outcomes could redefine how infrastructure upgrades are financed in the future.
In the UK, meanwhile, water companies are beginning to integrate PFAS testing and mitigation into existing capital investment programs. Thames Water, for instance, has undertaken enhanced PFAS monitoring in areas near historic industrial discharge points, though full-scale treatment remains in early stages.
Regulatory Momentum: Pushing Cities to Act
Another driver in municipal action is shifting regulation. In the United States, the Environmental Protection Agency (EPA) proposed new, enforceable Maximum Contaminant Levels (MCLs) for six PFAS compounds in March 2023. These limits—if finalized—would require utilities to remove PFAS down to parts-per-trillion levels, a move that’s pushing cities to adopt cutting-edge technologies sooner than they might have planned.
Across Europe, attention is also building. The EU’s Drinking Water Directive, updated in 2021, mandates member states to monitor 20 PFAS compounds and sets a combined limit of 0.5 µg/L. While enforcement varies by country, the directive signals a broader alignment in water quality standards—and the expectation that cities proactively comply.
UK regulators, such as the Drinking Water Inspectorate (DWI), have called on suppliers to intensify surveillance and develop action plans in areas where PFAS levels exceed 100 ng/L. While not yet a binding limit, these targets are already shaping public investment in filtration research and infrastructure upgrades.
Public Trust and Communication: Lessons Cities Have Learned
Ultimately, PFAS isn’t just a scientific problem—it’s a social one. Communities want to know that their water is safe, and they want transparency during any mitigation efforts. Cities that communicated early and clearly have earned more public trust.
Take the example of Ann Arbor, Michigan, where city officials launched an online PFAS dashboard providing real-time lab results, treatment updates, and historical data. Public meetings became a forum for scientists and residents alike, breaking down PFAS jargon into practical knowledge. The result? Less panic, more community buy-in for reforms, and even citizen-led water sampling initiatives that expanded monitoring coverage.
In contrast, cities that downplayed contamination issues or withheld information suffered setbacks—not just in public relations, but in the speed and scalability of their interventions.
Rethinking Long-Term Water Management Strategies
If one thing is clear, it’s that PFAS contamination is not a one-off crisis—it’s a generational challenge. And cities are beginning to plan accordingly.
From phasing out PFAS-containing firefighting foams in municipal use to collaborating on green infrastructure projects that limit wastewater runoff, urban water planners are weaving PFAS resilience into their long-term sustainability plans. Some are even reevaluating water sources, identifying new supply routes with lower contamination risks or investing in groundwater protection schemes upstream of treatment plants.
The city of Dordrecht in the Netherlands, for instance, not only upgraded filtration after PFAS pollution from a local DuPont plant but also rezoned nearby land to prevent future industrial development within its water catchment basin. It’s a preventative approach that echoes a simple question: Why treat what we could instead avoid contaminating in the first place?
What Comes Next?
The road ahead is fraught with scientific uncertainty, regulatory change, and financial hurdles—but it’s also one paved with innovation and collaboration. Cities are no longer asking “if” they should deal with PFAS; the question now is how fast and how effectively they can act.
From rural townships installing point-of-use filters to metropolitan hubs revamping entire water treatment protocols, real solutions are already underway. And while no single approach will work everywhere, the collective knowledge gathered across these initiatives offers a valuable resource for all cities facing the PFAS puzzle.
The only truly unacceptable response is inaction. Our water—our most basic public good—deserves no less than a comprehensive, science-driven, and community-centred defense.