Politics & Government

DEQ is proposing these limits on PFAS, 1,4-dioxane in drinking water supplies

DEQ is proposing rules that would limit forever chemicals in groundwater and surface water, as well as 1,4-dioxane in surface water. Pittsboro’s water treatment plant, shown here, has struggled with both chemicals in recent years.
DEQ is proposing rules that would limit forever chemicals in groundwater and surface water, as well as 1,4-dioxane in surface water. Pittsboro’s water treatment plant, shown here, has struggled with both chemicals in recent years. ssharpe@newsobserver.com

N.C. Department of Environmental Quality officials are trying to limit eight forever chemicals in water supplies throughout the state, as well as 1,4-dioxane in surface water.

Per- and polyfluoroalkyl substances, commonly referred to as forever chemicals, are long-lasting manmade compounds that have been linked with a spate of human health effects. The U.S. Environmental Protection Agency recently passed drinking water standards for six of these, and DEQ Secretary Elizabeth Biser said last week that the agency’s proposal will help utilities meet the new rules.

The EPA classifies the other chemical, 1,4-dioxane, as a likely human carcinogen. North Carolina residents, particularly those in the Cape Fear River basin, have some of the highest exposure to the industrial solvent of anyone in the country.

DEQ’s proposed limits on PFAS in groundwater include:

  • GenX chemicals: 10 parts per trillion
  • PFBA: 7,000 ppt
  • PFBS: 2,000 ppt
  • PFHxA: 4,000 ppt

  • PFHxS: 10 ppt
  • PFNA: 10 ppt

  • PFOA: 0.001 ppt

  • PFOS: 0.7 ppt

DEQ’s proposed limits on PFAS in surface water that supplies drinking water include:

  • GenX chemicals: 20 ppt
  • PFBA: 6,000 ppt
  • PFBS: 2,000 ppt
  • PFHxA: 3,000 ppt
  • PFHxS: 10 ppt
  • PFNA: 9 ppt
  • PFOA: 0.001 ppt
  • PFOS: 0.01 ppt

DEQ’s existing, non-enforceable target values for 1,4-dioxane in surface water are:

  • Fish supply consumption (for surface waters that are not drinking water supplies): 80,000 ppt
  • Drinking water supplies: 350 ppt

DEQ’s proposed 1,4-dioxane surface water standards as part of its triennial review are:

  • Fish supply consumption (for surface waters that are not drinking water supplies): 73,000 ppt
  • Drinking water supplies: 330 ppt

This story was produced with financial support from the Hartfield Foundation and Green South Foundation, in partnership with Journalism Funding Partners, as part of an independent journalism fellowship program. The N&O maintains full editorial control of the work. If you would like to help support local journalism, please consider signing up for a digital subscription, which you can do here.

This story was originally published May 8, 2024 at 5:10 AM with the headline "DEQ is proposing these limits on PFAS, 1,4-dioxane in drinking water supplies."

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Adam Wagner
The News & Observer
Adam Wagner covers climate change and other environmental issues in North Carolina. His work is produced with financial support from the Hartfield Foundation and Green South Foundation, in partnership with Journalism Funding Partners, as part of an independent journalism fellowship program. Wagner’s previous work at The News & Observer included coverage of the COVID-19 vaccine rollout and North Carolina’s recovery from recent hurricanes. He previously worked at the Wilmington StarNews.
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