BREAKING: New analysis indicates that toxics were present in Wilmington drinking water at extreme levels

By: - October 9, 2019 2:52 pm

Tests of samples collected between 2014 and 2016 reveal sky-high PFAS readings

Astronomical concentrations of toxic compounds commonly known as PFAS were present in the Cape Fear River near Wilmington, years before researchers had the technology to detect them.

According to a new analysis of preserved samples from 2014 to 2016, PFAS that contain an ether molecule were found at concentrations of at least as high as 130,000 parts per trillion near Lock and Dam No. 1, near the drinking water intake for the City of Wilmington. The contamination originated at the Chemours/DuPont facility more than 80 miles upstream.

The samples at Lock and Dam No. 1 were taken in 2015 near by NC State and EPA researchers. But only now, with advanced technology, can scientists more accurately measure the concentrations of PFAS in water.

The newly detected compounds are among the 5,000 types of PFAS. For this study, researchers broaden the scope of their search and discovered 11 that contained ether molecules. These include PFMOAA and Nation Byproduct 2. PFMOAA composed the greatest percentage of the ether subtypes contamination, with 110,000 ppt.

Since traditional water treatment methods can’t remove these compounds, they would have been present in drinking water that flowed from taps in tens of thousands of homes and businesses.

Prof. Detlef Knappe – Image N.C. State

“That’s the best estimate of what people in Wilmington were drinking for 37 years prior,” NC State professor and scientist Detlef Knappe told Policy Watch.

By comparison, state health and environmental officials have recommended that no one should drink water with levels of PFAS of any type above 70 ppt combined or above 10 ppt for a single compound.

The research team of NC State professor Detlef Knappe, graduate students Chuhui Zhang, Zachary Hopkins and James McCord, and Mark Strynar of the EPA in Research Triangle Park, published their findings this month in the peer-reviewed journal Environmental Science & Technology Letters. The research was partially funded by the NC Policy Collaboratory.

Chemours, which until 2015 was DuPont, discharged these perfluorinated and poly-fluorinated compounds into the Cape Fear River in its wastewater. The discharge contaminated the public drinking water supplies of people living downstream, as well as private wells that tap groundwater for drinking.

Chemours had not reviewed the research team’s findings by the Policy Watch deadline, and declined to comment. 

Vaughn Hagerty, spokesman for the Cape Fear Public Utility Authority issued a statement:

“We’re grateful for researchers such as Dr. Knappe, whose work continues to provide a more complete picture of how Chemours and DuPont chose to operate before regulators stepped in.

As troubling as these numbers are, they also may help explain a number of things, such as why we find still PFAS from Chemours and DuPont in raw and finished water we have analyzed. Or why we find their PFAS in our groundwater here in New Hanover County. Or the staggering concentrations of their PFAS in the groundwater under the Fayetteville Works, groundwater that regulators say migrates to the Cape Fear River. Or why researchers are confident that PFAS is in the miles of river sediment between the Fayetteville Works and our raw water intake.

Before the public outrage and regulatory scrutiny began in June 2017, the only thing Chemours said was done to address their PFAS discharges was “additional water emissions abatement technology” they said was added in November 2013 – after researchers found GenX in the Cape Fear. The 130,000-parts-per-trillion sample mentioned by Dr. Knappe was taken in 2014.

And, more to the point, I haven’t seen anything that indicates either Chemours or DuPont planned to do more after November 2013.

We’ve already spent millions of dollars to deal with their actions and we’re embarking on a $43 million project to add new granular activate carbon filters at Sweeney Water Treatment Plant to reduce PFAS. We’ll spend another $2.9 million a year to operate those enhancements.

Chemours speaks about its commitment to sustainability and the equipment it’s adding at the Fayetteville Works to address its PFAS releases. OK. But, look, if your kid has broken windows all over the neighborhood while hitting baseballs over the past few years, you haven’t solved the problem by simply getting her a batting cage. You still have to pay to fix all of those broken windows.”

Chemours ostensibly stopped discharging PFAS, including GenX, into the Cape Fear River in 2018, months after the Department of Environmental Quality revoked its permit. In April 2018, DEQ asked a Bladen County judge to intervene.

Sharon Martin, DEQ spokeswoman also released a statement:

“DEQ’s actions to stop the wastewater discharges and reduce GenX air emissions had an immediate impact as current sampling by DEQ and by the PFAST Network shows concentrations of PFOA and PFAS below the EPA lifetime Health Advisory Limit and concentrations of GenX below the DHHS provisional health goal.

Under the consent order, Chemours is also required to develop a PFAS loading reduction plan for the Cape Fear River, complete a sediment study and develop methods to test for additional PFAS compounds going forward.

Beyond Chemours, DEQ is requiring publicly owned utilities with pretreatment programs and industrial dischargers in the Cape Fear River Basin to screen for PFAS compounds as part of a larger effort to detect and control PFAS pollution.

GenX and emerging compounds are a priority issue. Though we have significantly reduced the contamination from Chemours, we are not done. We will continue to track the sources of PFAS contamination and take action to protect North Carolinians and improve water quality in our state.”

DEQ and Cape Fear River Watch entered a consent order with Chemours to  sharply curb both water and air emissions.

Many PFAS, though, persist in the environment, giving rise to the term “Forever Chemicals.”

Exposure to two types — PFOA and PFOS — have been linked to an increased risk of testicular cancer, kidney cancer, thyroid disorders, elevated cholesterol and high blood pressure during pregnancy.

Scientists suspect that based on the molecular make up, other types of these compounds are also toxic, but more study is needed.

Knappe had the foresight to preserve the old samples in case technology would some day allow researchers to re-analyze them. Previously, the lab didn’t have “standards,” meaning samples of the compounds used to calibrate the equipment, such as high-end, sensitive mass spectrometers.

“We couldn’t tell people what the concentration was,” Knappe said. “The main thing that’s new here is that then we didn’t have analytical standards to calibrate the instruments. We were finally able to put concentrations to each one of these compounds, and it gave us these really astounding kind of levels.”

Researchers also re-analyzed Cape Fear River samples taken in 2014 85 miles upstream, near the Chemours facility at the Huske Lock and Dam. The total concentrations of ether compounds were even higher: 990,000 ppt. (This paragraph has been corrected to reflect the extreme levels were detected only in 2014, not 2018.)

Knappe said these astronomical concentrations could have occurred because the river water and the wastewater discharge had not fully mixed.

In 2015-2016, the EPA’s method of testing drinking water for PFAS targeted only 14 compounds —and none of them with the ether molecules.

“If the water would have had Nafion byproducts or GenX, would you have been able to tell? The answer is no,” Knappe said.

Researchers also found low levels of Nafion Byproduct 2, which Chemours discharged in its wastewater as part of the manufacturing process. However, those concentrations could be misleading. “Chemours didn’t run all of the processes all of the time,” Knappe said. And since the samples are several years old, some of the compounds, like Nafion Byproduct 2 may have degraded over time, causing the concentrations to appear artificially low.”

Even though PFMOAA might not be detected in people’s blood, they may still have been exposed. PFMOAA does not accumulate in the body, Knappe said, but if people drink water with this level of contaminants every day, it could harm their health.

More toxicology studies are needed, Knappe said, to fully understand how these compounds affect human health and the environment.

In addition, scientists and regulators need more comprehensive testing methods to detect as many PFAS compounds as possible.

These samples were collected in 2015 from near Lock and Dam No. 1, near Wilmington.
The first column indicates the concentrations for the compounds before researchers applied a chemical process called oxidization. The second column shows the concentrations after oxidization, which was applied in 2019 to the samples, which had been preserved.


These samples were collected in 2014  from near the Huske Lock and Dam near the Chemours facility. The first column indicates the concentrations for the compounds before researchers applied a chemical process called oxidization. The second column shows the concentrations after oxidization, which was applied in 2019 to the samples, which had been preserved.

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Lisa Sorg
Lisa Sorg

Assistant Editor and Environmental Reporter Lisa Sorg helps manage newsroom operations while covering the environment, climate change, agriculture and energy.