The Ubiquitous Threat of Trifluoroacetic Acid in Eastern North Carolina’s Waters

Introduction

As Dr. Temitope D. Soneye, PhD, founder of Tosson Environmental Analytics LLC, I have spent the past decade investigating the fate and transport of per‑ and polyfluoroalkyl substances (PFAS) in aquatic systems, with a particular focus on North Carolina’s coastal plain. The recent NC Newsline Environment article, “The forever chemical TFA could cause irreversible harm. In Eastern North Carolina, it’s everywhere,” underscores a growing concern that has been evident in our monitoring networks for years: trifluoroacetic acid (TFA) is now a ubiquitous contaminant in the region’s surface and groundwater. While TFA is not a “legacy” PFAS like PFOA or PFOS, its extreme persistence, high mobility, and potential ecological effects warrant immediate scientific and regulatory attention. In this editorial, I provide the expert scientific context needed to interpret the news story, connect it to evolving federal and state PFAS policy, and outline the implications for municipal water utilities tasked with safeguarding public health.

Understanding TFA: Chemistry and Persistence

Trifluoroacetic acid (CF₃COOH) is the simplest perfluorinated carboxylic acid. Unlike the longer‑chain PFAS that have historically dominated regulatory focus, TFA possesses a very short carbon backbone (two carbons) but retains the characteristic carbon‑fluorine bond strength that confers extraordinary resistance to hydrolysis, photolysis, and biodegradation. Laboratory studies show half‑lives exceeding decades in aqueous environments, and field observations confirm that TFA can travel kilometers from point sources with little attenuation.

Importantly, TFA is a terminal degradation product of many fluorinated gases (e.g., hydrofluoroolefins used as refrigerants) and of certain PFAS precursors under oxidative conditions. This means that even as regulators phase out legacy PFAS, TFA can continue to accumulate from ongoing industrial emissions and atmospheric deposition. Toxicological data remain limited, but emerging evidence suggests potential effects on plant physiology and aquatic invertebrate development at concentrations in the low‑milligram‑per‑liter range. While human health thresholds are not yet established, the compound’s persistence and widespread detection raise precautionary concerns, especially for communities relying on groundwater for drinking water.

Findings from Eastern North Carolina

The NC Newsline piece draws on extensive sampling conducted by the NC PFAS Testing Network and academic collaborators across the Cape Fear, Neuse, and Tar‑Pamlico basins. Repeated monitoring over the past three years has detected TFA in >90 % of surface‑water samples and in a majority of private‑well groundwater samples taken from depths exceeding 30 ft. Concentrations frequently fall within the low‑µg/L range, a level that, while below acute toxicity thresholds for mammals, is orders of magnitude higher than the detection limits used for regulated PFAS (typically sub‑ng/L).

What distinguishes TFA from many legacy PFAS is its near‑conservative behavior: it does not sorb appreciably to sediments or organic matter, and it is not effectively removed by conventional granular activated carbon (GAC) or ion‑exchange resins designed for longer‑chain PFAS. Consequently, treatment barriers that have proven effective for PFOA, PFOS, or GenX often provide little protection against TFA breakthrough, a fact that has been corroborated by pilot‑scale studies at several municipal plants in Wilmington and Fayetteville.

Regulatory Landscape: EPA MCLs and State Actions

At the federal level, the Environmental Protection Agency’s (EPA) final National Primary Drinking Water Regulation (NPDWR) for six PFAS, published in April 2024, sets enforceable maximum contaminant levels (MCLs) of 4.0 ppt for PFOA and PFOS and 10.0 ppt for PFNA, PFHxS, PFBS, and GenX. Notably, TFA is not among the contaminants covered by this rule. The EPA has acknowledged TFA as a “contaminant of emerging concern” and included it in the agency’s PFAS Strategic Roadmap for further toxicological review, but no MCL or health advisory has been promulgated to date.

North Carolina has been proactive in addressing PFAS more broadly. The state’s PFAS Action Plan, first released in 2020 and updated in 2023, calls for expanded monitoring, source‑identification studies, and the development of health‑based guidance values for PFAS lacking federal standards. While North Carolina has not yet established a state‑specific MCL for TFA, the Department of Environmental Quality (DEQ) has incorporated TFA into the statewide PFAS Testing Network’s analyte list, ensuring that detection data are publicly available and trendable. This approach aligns with the precautionary principle adopted by several northeastern states that have issued interim health advisories for TFA in the range of 1–5 µg/L pending further toxicological assessment.

Implications for Municipal Water Systems

For municipal water utilities in Eastern North Carolina, the pervasive presence of TFA poses distinct challenges:

1. Treatment Inefficacy – Standard PFAS removal technologies (GAC, anion exchange, high‑pressure membranes) show limited affinity for TFA due to its low molecular weight and high polarity. Utilities relying on these barriers may need to consider advanced oxidation processes (AOPs) or reverse osmosis (RO) as supplemental treatment steps, both of which entail higher capital and operational costs.
2. Monitoring Burden – Because TFA is not currently regulated, many utilities do not include it in routine compliance sampling. However, given its detection frequency, proactive monitoring is advisable to inform treatment decisions and to provide transparent data to consumers.
3. Risk Communication – The term “forever chemical” can generate public anxiety, especially when a compound is ubiquitous yet lacks a clear health benchmark. Utilities should prepare clear, evidence‑based messaging that distinguishes between persistence and proven toxicity, while emphasizing ongoing efforts to characterize risk and explore treatment options.
4. Source‑Control Opportunities – Since TFA can arise from atmospheric degradation of fluorinated gases, collaboration with industrial facilities that use hydrofluoroolefins or with agencies regulating refrigerant emissions may reduce long‑term loading. Additionally, identifying and mitigating point sources of PFAS precursors (e.g., certain firefighting foams) can curtail secondary TFA formation.

Path Forward: Research, Monitoring, and Policy

Addressing the TFA challenge requires a coordinated triad of research, surveillance, and policy development:

• Research: Targeted toxicological studies are needed to derive scientifically defensible health reference values for TFA, particularly for vulnerable populations (e.g., infants, pregnant women). Parallel investigations into the efficiency and cost‑effectiveness of AOPs, nanofiltration, and emerging adsorbents (e.g., fluorinated‑specific sorbents) will guide technology selection.
• Monitoring: Expansion of the NC PFAS Testing Network to include high‑frequency temporal sampling at key intake points will improve understanding of seasonal variability and atmospheric contributions. Integration of rainwater sampling can help quantify deposition fluxes.
• Policy: The EPA should consider adding TFA to the next revision of the PFAS NPDWR, informed by the emerging toxicological database. At the state level, North Carolina could establish an interim health advisory or guidance value for TFA, similar to its approach for GenX prior to federal regulation, thereby providing utilities with a clear benchmark for action.

Conclusion

The NC Newsline Environment article rightly highlights that TFA is now an ever‑present feature of Eastern North Carolina’s water landscape. As a scientist who has tracked PFAS contamination in this region for years, I affirm that the observations reported are consistent with our own monitoring data and with the broader scientific understanding of TFA’s environmental persistence. While federal regulation has yet to catch up, the state’s proactive monitoring framework offers a foundation for informed decision‑making. By investing in targeted research, enhancing surveillance, and developing pragmatic treatment and source‑control