PFAS Contamination in NC Groundwater Could Linger for Over 40 Years

A recent North Carolina State University study paints a concerning picture of groundwater contamination in Cumberland and Bladen counties. The study focuses on per- and polyfluoroalkyl substances (PFAS)—a class of chemicals often called "forever chemicals" for their extreme environmental persistence. Researchers estimate it will take more than four decades for the natural flow of groundwater to flush these chemicals out, even under the best circumstances. The prolonged contamination seriously threatens local populations, agricultural lands, and downstream water sources like the Cape Fear River.

New Insights into PFAS Contamination in North Carolina

The NC State research team employed a unique method by integrating data on PFAS levels, groundwater flow rates, and groundwater age-dating techniques. This allowed them to predict PFAS concentrations historically and in the future, particularly in groundwater discharging into streams that feed the Cape Fear River.

The researchers collected samples from two watersheds adjacent to the Fayetteville Works fluorochemical plant, a significant source of PFAS pollution. According to Dr. David Genereux, lead researcher and professor of marine, earth, and atmospheric sciences at NC State:

"This contamination spans a huge area, impacting private wells and agricultural land while also contributing to PFAS flow into the Cape Fear River."

More than 7,000 private wells are in the contamination zone, putting families and farmers at direct risk. Compounding this, the groundwater polluted with PFAS eventually reaches tributaries of the River, affecting downstream users, including the city of Wilmington and other nearby communities.

Key Findings from the Study

The study revealed alarming data about the concentration and longevity of PFAS chemicals in the region's groundwater:

• High PFAS Levels Detected: Two specific PFAS chemicals—hexafluoropropylene oxide-dimer acid (HFPO−DA) and perfluoro-2-methoxypropanoic acid (PMPA)—were found in groundwater at average concentrations of 229 and 498 nanograms per liter (ng/L), respectively. These levels vastly exceed the EPA’s maximum contaminant level (MCL) of 10 ng/L for HFPO−DA in drinking water.
• Groundwater Contamination Spanning Decades: The research found PFAS contamination in groundwater as old as 43 years, with much of the pollution likely stemming from high-emission periods between 1980 and 2019. Genereux warns that the natural flushing process could take even longer than 40 years if the chemicals have diffused into deeper, less permeable soil layers.
• Continued Risk of Contamination: Although PFAS air emissions from the Fayetteville plant have dropped significantly since 2019, the researchers caution that some deposition continues. This means the groundwater could remain contaminated for longer, posing ongoing risks to local and downstream populations.

Impacts on Local Communities and Water Supplies

This contamination presents a two-fold problem for the region. First, private well users in the area are directly exposed to PFAS through their drinking water. With more than 7,000 wells potentially impacted, residents face long-term health risks from chemicals linked to serious illnesses, including cancer, liver damage, and developmental issues in children.

Second, the contamination also affects surface waters. PFAS-contaminated groundwater flows into the Cape Fear River and its tributaries, important drinking water sources for downstream communities, including Wilmington. This pollution creates a cascade of health risks that could affect tens of thousands of people.

According to Genereux:

"Even with best-case scenarios, where no additional PFAS enters the system, we’re still looking at over four decades before the groundwater naturally flushes itself out."

This research underscores that the problem of PFAS is not just an immediate threat—it’s a multigenerational issue requiring sustained attention and remediation efforts.

What’s Next?

Looking ahead, the team aims to develop more detailed models that predict future PFAS levels in individual drinking wells. They also plan to collaborate with toxicologists to understand better how past PFAS levels in well water correlate with health outcomes. Such insights could help guide future public health policies and mitigation strategies.