Per- and polyfluoroalkyl substances, commonly referred to as PFAS, have garnered increasingly urgent attention due to their widespread contamination of drinking water sources and ecosystems. A recent study conducted by researchers at North Carolina State University highlights a disturbing revelation regarding the persistence of these chemicals in groundwater, specifically in Cumberland and Bladen counties. Utilizing an innovative approach that combines historical data with current groundwater analysis, this study outlines just how long communities in North Carolina may be affected by PFAS contamination.
The research focused on two watersheds near the Fayetteville Works fluorochemical plant in Bladen County. By sampling groundwater from these areas and employing age-dating tracers alongside atmospheric contamination data from the North Carolina Department of Environmental Quality, the researchers sought to create a model to predict future PFAS concentrations in tributaries that feed into the Cape Fear River. This approach not only provided insights into the current status of PFAS in groundwater but also allowed the scientists to forecast its trajectory.
Throughout their research, the team unearthed PFAS in groundwater that is up to 43 years old. They identified alarmingly high levels of two prominent PFAS compounds—hexafluoropropylene oxide-dimer acid (HFPO-DA) and perfluoro-2-methoxypropanoic acid (PMPA)—which averaged 229 and 498 nanograms per liter, respectively. For context, the U.S. Environmental Protection Agency has established a maximum contaminant level (MCL) for HFPO-DA in public drinking water at just 10 ng/L, underscoring the gravity of the contamination levels being faced by local communities.
The ramifications of this investigation are significant, particularly for residents relying on private wells for their water supply. With over 7,000 private wells in the affected region, the implications for health and safety cannot be underestimated. Not only are these wells a direct source of PFAS contamination for households, but the eventual discharge into tributaries of the Cape Fear River exacerbates the issue for downstream users, including those in Wilmington.
David Genereux, the lead researcher and professor of marine, Earth, and atmospheric sciences at NC State, noted that the extensive area of contaminated groundwater poses dual risks: direct exposure to polluted water sources and the downstream impact on larger water bodies, which are critical for other communities. This interplay of localized and broader impacts accentuates the need for immediate and effective remediation strategies.
The newly developed model predicts an unsettling timeline for the natural flushing of PFAS from the groundwater. According to Genereux, it could take over 40 years for the chemicals to dissipate, assuming no further atmospheric deposition occurs. This projection raises pressing questions about environmental policies and the management of PFAS emissions moving forward. Although emissions have diminished since 2019, they have not ceased entirely, and lingering atmospheric PFAS deposition continues to contribute to groundwater contamination.
The study emphasizes that the extent of groundwater PFAS contamination may be understated. If PFAS chemicals are diffusing into and out of lower permeability layers in the groundwater system, the flushing timeline could extend even further than the 40 years predicted. The challenge becomes one of not only monitoring and assessment but also implementing proactive measures to mitigate the ongoing contribution of PFAS from atmospheric sources.
The North Carolina State University study serves as a clarion call for awareness regarding the pervasive nature of PFAS contamination and its long-term implications. Communities situated near contaminated sites must grapple with both immediate health risks and the prolonged timeline for remediation that could span several decades. Effective strategies need to be urgently developed to address PFAS presence in groundwater, safeguard public health, and protect local ecosystems. As research continues in this critical area, it is essential for policymakers, scientists, and communities to collaborate in addressing the ongoing challenges posed by these stubborn pollutants.