GenX: What Is Nafion, And Why Is It In The Water

Aug 31, 2017

The N.C. Department of Environmental Quality this week urged Chemours to stop discharging two additional chemical compounds into the Cape Fear River. EPA scientists told the state they have identified two compounds they are calling Nafion byproducts 1 and 2.

The following is a written statement from the North Carolina Department of Environmental Quality, released Thursday, August 31. 

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The compounds were identified in the company’s waste stream by a U.S. Environmental Protection Agency preliminary analysis, shared this week.

DEQ is looking at all legal options to stop the discharge.

EPA scientists told the state they have identified two compounds they are calling “Nafion byproducts 1 and 2” in Chemours’ waste stream and that estimated concentrations of these compounds are not decreasing.

The new information is the result of the EPA’s analysis of water samples submitted by DEQ to the EPA’s lab in Research Triangle Park. Information about the presence of the Nafion byproducts comes from preliminary analysis of water samples gathered by DEQ at Chemours’ wastewater discharge outfall near Fayetteville and finished drinking water at the Sweeney Water Treatment Plant in Wilmington. Scientists at the EPA lab are conducting further analysis of the water samples.

Preliminary results shared by the EPA this week also include three perfluorinated compounds that along with GenX were previously identified in the Cape Fear River by a 2016 study by the EPA and N.C. State University.

Estimated concentrations of these three perfluorinated compounds dropped significantly, similar to GenX levels after the company stopped discharging GenX. For that reason, state and federal officials believe the three perfluorinated compounds were part of the same wastewater discharge that included GenX and was stopped.

The accuracy of the laboratory analysis for the five chemicals included in the EPA’s preliminary results is more uncertain than those available for GenX because calibration standards for these chemicals are not commercially available. EPA is using new non-targeted screening methods to develop concentration estimates for these five chemicals. With non-targeted screening, researchers are able to test for and identify chemicals present, rather than testing to see if a particular chemical is present. This is different from the more commonly known targeted screening, which is when researchers identify what they are looking for in the water and then test for those specific things.

Little is known about the health effects of any of the five compounds—Nafion byproducts 1 and 2 or the three other perfluourinated compounds – included in this week’s analysis from the EPA.

Public health experts with DHHS used available studies to establish a health goal for GenX. Since the GenX discharge stopped, concentrations of GenX have dropped well below the state health goal of 140 parts per trillion.

No similar health studies have been identified for the Nafion byproducts or the other three perfluorinated compounds analyzed by the EPA, so DHHS is unable to establish a health goal for them at this time.

“I know how frustrating it is to all of us that we have very little scientific information about these unregulated, emerging compounds,” said Mandy Cohen, secretary of the N.C. Department of Health and Human Services. “We continue to work with the Environmental Protection Agency, the Centers for Disease Control and Prevention and other scientists to get more information as quickly as possible.”

As part of the ongoing investigation, DEQ requested that the EPA analyze water samples for GenX and other unregulated chemical compounds included in the 2016 study conducted by the EPA and N.C. State University. Among those chemicals are the perfluorinated compounds the EPA reported this week.

The EPA also chose to analyze the water samples for the Nafion byproducts based on a separate prior study by the federal agency. Specialists with the EPA’s lab in Research Triangle Park conducted the analysis using new technology and methodology and looked at water samples collected by DEQ over a six-week period starting June 19.

DEQ will review all this information as part of its investigation and the agency’s review of Chemours’ application for a new wastewater discharge permit.   

The EPA informed state officials this week that it is working on a report that will include concentrations of other compounds at multiple sampling locations over multiple weeks.

As with the results for GenX, DEQ will make public test results for all the compounds when final data is available.