North Carolina court upholds DEQ authority to set 1,4-dioxane permit limits

The Wake County Superior Court has upheld the North Carolina Department of Environmental Quality’s (DEQ) authority to establish wastewater discharge permit limits for 1,4-dioxane, reversing a 2024 Office of Administrative Hearings decision that removed the limits from the City of Asheboro’s permit.

In its Feb. 5 ruling, the court found that DEQ followed proper state and U.S. Environmental Protection Agency protocols in developing the 1,4-dioxane limits and “created the criteria for the purpose of protecting the health and wellbeing of North Carolinians.”

DEQ had identified elevated levels of 1,4-dioxane — an industrial solvent classified as a likely human carcinogen — in discharges from Asheboro’s wastewater treatment plant. The agency has been monitoring municipal wastewater effluent and surface waters across 15 river basins, including the Cape Fear, to identify sources of the contaminant.

“Because 1,4-dioxane is a pollutant likely to cause cancer in humans, permit limits are necessary to protect North Carolinians’ drinking water and their health,” said DEQ Secretary Reid Wilson in a press release. “The court order vindicates DEQ’s decision to impose limits to protect downstream communities from this harmful carcinogen.”

Attorney General Jeff Jackson added, “The Superior Court was right to uphold DEQ’s ability to limit chemicals in our water, and my office will continue working with DEQ to make sure people have clean drinking water.”

The ruling reinforces state authority to impose contaminant-specific limits in National Pollutant Discharge Elimination System permits as utilities and regulators nationwide continue addressing emerging contaminants in wastewater effluent.