Dulles Airport’s PFAS levels hit 50x the federal limit. The reservoir serves 1 million people with no treatment removing the chemicals. What residents can do now.
Eleven of the sixteen industrial sites monitored in the Occoquan Reservoir watershed are releasing PFAS at levels exceeding federal and state drinking water standards, according to data obtained by the Prince William Times through a Freedom of Information Act request. The reservoir provides drinking water for approximately 1 million residents in Northern Virginia's Prince William and Fairfax counties.
The data, collected over the past year under a 2025 state law requiring industrial polluters to report their PFAS emissions, reveals that treatment to remove the chemicals from finished drinking water does not yet exist in the watershed. The contaminants flow from industrial outfalls through the watershed and into the reservoir that supplies the region's taps.
Airport and semiconductor plant lead emissions
Dulles International Airport recorded the highest contamination levels, with total PFAS concentrations reaching 6,469 parts per trillion. The airport's PFOS levels peaked at 195 parts per trillion, nearly 50 times the EPA's 4 parts per trillion limit that takes effect in 2029. PFOA levels at Dulles reached 148 parts per trillion.
Airports are known PFAS sources because they use aqueous film-forming foam, or AFFF, to extinguish jet-fuel fires. The foam contains PFAS chemicals that persist in soil and water. Joseph Olmo, a spokesperson for the Metropolitan Washington Airports Authority, said the authority is working on a compliance plan to evaluate treatment approaches.
Micron's Manassas semiconductor manufacturing plant ranked second, with total PFAS emissions as high as 1,391 parts per trillion from a single wastewater outfall. The plant's PFOA levels peaked at 66 parts per trillion, 17 times the federal standard. Semiconductor manufacturing requires PFAS because the chemicals withstand the high heat involved in chip fabrication. Tate Tran, a Micron spokesperson, said the company "takes its environmental compliance obligations seriously" and is evaluating additional wastewater treatment options.
Other emitters and a hard deadline
Beyond the top two polluters, elevated PFAS levels were also detected at a Sunoco fuel terminal in Manassas, a county-owned composting facility, Manassas Regional Airport, and a Lockheed Martin facility that builds undersea warfare technology. Prince William County spokesperson Nicole Brown said the composting facility will submit a remediation plan by July 2029.
The urgency behind the monitoring law comes from drinking water tests at Fairfax Water's Griffith Water Treatment Plant, which supplies eastern Prince William County. In 2023, PFOA levels at the plant reached 8.7 parts per trillion. PFOS levels hit 6.3 parts per trillion in 2024. Both exceed the federal standard that utilities must meet by 2029.
Who pays: ratepayers or polluters?
David Bulova, Virginia's secretary of natural and historic resources and a former state delegate, sponsored the effluent monitoring legislation while serving in the House of Delegates. He framed the choice facing regulators in direct terms.
"Your average family, your small businesses, they're ultimately picking up the tab for other groups putting PFAS into the water," Bulova said. "And so, for me, the polluter ought to pay."
The alternative would require Fairfax Water to install reverse osmosis or similar treatment at its plant, at an estimated cost of $400 million plus $25 million annually in recurring expenses. Those costs would be passed to ratepayers through higher utility bills. If industrial emitters reduce their output to federal limits, Bulova said, the region's drinking water should fall below the threshold without rate increases.
"This gives us a fighting chance to reduce those sources, which ultimately should mean that PFAS levels in our drinking water will go down," he said.
No treatment in place for finished water
The Griffith Water Treatment Plant, like most municipal facilities, was not designed to filter PFAS compounds. The burden falls on industrial emitters to treat their own discharges by the 2029 deadline. Until then, residents receive water from a reservoir fed by outfalls that exceed safety standards by orders of magnitude.
PFAS are known as "forever chemicals" because they do not break down easily in the environment or the human body. The CDC's Agency for Toxic Substances and Disease Registry has linked certain PFAS compounds to cancer, thyroid disease, liver damage, immune system effects, and developmental delays.
Are you affected? What to do
If you're in Prince William or Fairfax County:
- Request your utility's latest water quality report, which should include PFAS testing results from the Griffith Water Treatment Plant
- Consider a point-of-use filter certified for PFAS removal while awaiting watershed-level treatment
Check your own water:
- City water: Look up your utility's annual water quality report with the EPA's report search. EWG's Tap Water Database also shows results by ZIP code; its health guidelines are stricter than the legal limits.
- Private well: No one tests it for you. See the EPA's private well guidance.
- Testing for PFAS: For a home check, SpringWell's mail-to-lab PFAS test analyzes one sample for 25 PFAS compounds using EPA Method 533 (we may earn a commission).
- Choosing a filter: If testing shows PFAS in your water, choose a filter certified to reduce PFOA and PFOS (NSF/ANSI 53 or 58). Our PFAS filter guide lists certified picks by type.
For everyone:
- If your utility sources from a watershed with industrial emitters, request PFAS-specific test results, as many utilities did not test for these compounds until recently
What filters actually remove PFAS from tap water
PFAS contamination at the watershed level means the chemicals can reach your tap even when treatment plants meet other safety standards. Unlike bacteria or sediment, PFAS compounds are not removed by standard municipal treatment processes. For household protection, filtration must happen at the point of use.
Reverse osmosis systems certified to NSF/ANSI 58 are among the most effective options, with peer-reviewed studies showing removal rates above 90% for both long-chain and short-chain PFAS. Activated carbon filters can reduce some PFAS compounds, though performance varies significantly by filter type and contact time. Our reverse osmosis system reviews cover under-sink and countertop models that meet certification standards for PFAS reduction.
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