A legal battle over the regulation of 1,4-dioxane, a likely carcinogen, has escalated into a showdown between the Environmental Protection Agency (EPA) and North Carolina, with the city of Asheboro at the center. Following a judge’s ruling that halted state-imposed discharge limits, Asheboro has dramatically increased its release of the chemical into the Cape Fear River watershed, raising concerns for downstream communities.
1,4-dioxane, a synthetic chemical used in various industrial processes, including the manufacturing of polyester plastics, has become a significant environmental concern in North Carolina, which has the third-highest concentration of the chemical in the country. In 2016, the North Carolina Department of Environmental Quality (DEQ) imposed discharge restrictions on wastewater facilities in Asheboro, Greensboro, and Reidsville, identifying them as major contributors to the chemical’s presence in the state’s waterways.
However, in September, Chief Administrative Law Judge Donald van der Vaart ruled in favor of Asheboro in a lawsuit challenging these restrictions. The municipalities argued that the limits placed undue financial burdens on their wastewater facilities and local industries, claiming DEQ overstepped its authority by regulating 1,4-dioxane without explicit numerical limits codified in state law. This ruling led to a surge in Asheboro’s 1,4-dioxane discharges, with tests in December showing levels far exceeding the EPA’s cancer risk threshold.
The discharges flow into the Deep River, a tributary of the Cape Fear River, impacting drinking water supplies for communities including Sanford, Fayetteville, Brunswick, Pender, and New Hanover Counties. Downstream communities, including the Cape Fear Public Utility Authority, have strongly opposed the increased discharges.
The EPA has now stepped in, issuing a letter to DEQ demanding the reinstatement of 1,4-dioxane discharge limits within 90 days or face federal takeover of permit enforcement. The EPA refuted Judge van der Vaart’s interpretation of the Clean Water Act, asserting that the act does not require a chemical to be formally designated as a carcinogen for regulation if toxicological data demonstrates a threat to human health.
This dispute has also brought scrutiny to the role of experts and lobbying. The municipalities’ expert witness, Michael Dourson, has faced criticism for his industry ties and research funded by companies with a vested interest in 1,4-dioxane regulation.
The situation remains fluid, with DEQ reviewing the EPA’s letter and an appeal of the original ruling pending in Wake County Superior Court. This case has significant implications for environmental regulation in North Carolina and the nation, potentially setting a precedent for the regulation of other emerging contaminants like PFAS.
