For years, communities in North Carolina have struggled with high levels of PFAS in their water.
PFAS, often called “forever chemicals,” are harmful, man-made substances that do not easily break down in the environment or in the human body.
They have been linked to serious health problems and have been found in drinking water, rivers, soil, and even food.
Now, researchers at Duke University believe they have finally solved the mystery of where much of this contamination in the Piedmont region has been coming from.
The breakthrough came after scientists focused their attention on the city of Burlington.
At first, the source of the pollution was extremely difficult to identify because the chemicals being released were not the usual types of PFAS that are commonly tested for and regulated.
Instead, a local textile manufacturing facility was sending tiny solid particles known as PFAS “precursors” into the sewer system.
These precursors do not show up in standard tests, but over time they slowly break down into the harmful PFAS compounds that scientists normally measure in water supplies.
Even more alarming was the concentration of these particles. The researchers found levels as high as 12 million parts per trillion in some samples.
This is millions of times higher than the limit recently set by the U.S. Environmental Protection Agency for certain types of PFAS in drinking water.
Normally, these precursor particles transform into harmful PFAS very slowly. However, Burlington’s wastewater treatment plant had been using a special process that applies heat and pressure to break down waste.
While designed for other purposes, this method accidentally sped up the conversion of the “hidden” PFAS precursors into the dangerous forms that contaminate water. That is why the treated water coming out of the plant had much higher PFAS levels than the water flowing in.
Once researchers realized this, the city shut down that treatment process, and PFAS levels in the wastewater dropped quickly.
But the problem did not completely disappear. For years, the sludge left over from the treatment plant had been turned into fertilizer and spread on farmland across the region.
These biosolids contain PFAS precursor particles, which can continue to break down and leak chemicals into the soil and waterways for decades.
To track down the exact source, Duke researchers, led by Professor Lee Ferguson and his team, collected and tested sewage and wastewater samples from around Burlington. At first, nothing seemed unusual.
Then they put the samples through a process that mimicked the old treatment system. Suddenly, the PFAS levels in wastewater from one specific textile manufacturer skyrocketed by tens of thousands of percent. The team later discovered that the pollution came from tiny, solid nanoparticles used in fabric treatments designed to make textiles water- and stain-resistant.
With this information, Burlington worked with the manufacturer to change its practices and drastically reduce the release of these particles. Since then, downstream communities have also seen major drops in the amount of PFAS detected in their drinking water. This shows that solving the problem at its source can be more effective than trying to remove the chemicals after they have already spread.
However, concerns remain. The long-term impact of years of contaminated fertilizer on farmland is still unknown. Scientists are now calling for more research to understand how these particles move through the environment and how long they will continue releasing PFAS.
This discovery is both a warning and a lesson. It shows that dangerous pollution can come from unexpected forms, stay hidden for years, and require new ways of thinking to detect.
It also offers hope that, with careful science and cooperation, communities can take meaningful steps to stop “forever chemicals” at their source.
Source: Duke University.
