The Duke researchers who discovered trace amounts of contaminants in water sources around the Triangle last year think they may be closer to understanding where they're coming from. The potentially toxic contaminants, known as perfluorinated chemicals, or PFCs, are known to be especially elusive and difficult to track.
But at a forum last month sponsored by the Sierra Club and N.C. Central, Lee Ferguson, an environmental analytical chemist at Duke University, said that his team might have some ideas. In some cases, the chemicals could be coming from sewage that is recycled and used for agriculture. The repurposed sewage can flow into tributaries of larger bodies of water. And since wastewater treatment plants aren't accustomed to looking for these little-known compounds, they're not especially good at removing them from drinking water. In other cases, the chemicals could be carried through rainwater or the air.
Durham's assistant director of water management, Vicki Westbrook, announced that Durham's latest tests showed low levels of PFCs in the water. However, Westbrook doesn't believe that they're coming from water runoff but rather "some sort of aerosolized deposit that's floating over when it rains, and it ends up there."
Ferguson and his colleague, Heather Stapleton, collected water samples from various sources, including their home faucets, last year. Most contained detectable levels of fluorinated organic chemicals referred to as PFOAs and PFOSs, which the Environmental Protection Agency says cause cancer, liver damage, and birth defects, among other possible health issues, at high enough levels. It's important to note that while Ferguson and Stapleton discovered these chemicals, they did so at levels well below what the EPA considers dangerous.
However, the combined level of a broader range of chemicals collectively known as PFAs, for which the EPA has not yet written a health advisory, was substantially higher in Cary and Jordan Lake. Ferguson says that's at least cause for further investigation.
Rachel Monschein, a laboratory supervisor for the town of Cary, won't speculate on the source of the PFAs but says that her team has been in touch with the scientists who discovered them.
A great deal of attention has been paid to GenX, a PFA that was recently discovered along the Cape Fear River. Created as a supposedly safer alternative to its predecessors, GenX was found emanating from the Fayetteville plant of Chemours, a spinoff of DuPont that manufactures Teflon and other nonstick coatings. The chemicals had likely been discharging as a byproduct since the 1980s. N.C. State is exploring the effects of the contaminant on residents in the Wilmington area, where the chemical has been frequently detected in drinking water.
Chemicals like PFOAs and PFAs are known as emerging contaminants because scientists have only recently developed the tools to identify them in water systems. Additionally, some of the substances are new; they've been created by manufacturers for a specific purpose, and it's difficult to keep track of them all.
There are eighty-five thousand chemicals used in commerce, according to the EPA's chemical substance inventory. And that's not including the multitude of byproducts that they transform into when they escape into the environment. Meanwhile, only sixty-five pollutants or groups of pollutants have been labeled toxic under the Clean Water Act, and the EPA has only ever banned nine chemicals.
Erin Carey, the coastal programs coordinator of the North Carolina chapter of the Sierra Club, says that disparity proves that there are lots of chemicals that regulatory agencies can't keep up with.
"The mix of chemicals that we're ingesting in our drinking water should be of the utmost concern because we have no idea how they interact with each other in the body or in the environment," Carey says. "In a lot of cases, that [health advisory level] is a shot in the dark, and it is not based on hard evidence. It is not based on long-term studies of humans. Often they are animal studies, and only partially released animal studies, because these companies claim that the information or the data is proprietary."
One potential problem, environmental advocates say, is that the state Department of Environmental Quality might not have the resources to effectively tackle elusive contamination patterns such as those discovered in Jordan Lake. At a recent tour for state representatives of DEQ labs, DEQ officials insisted that their staff members were working tirelessly to track PFAs and PFOAs across North Carolina, but the lack of state funding was making their job increasingly difficult.
The DEQ's evolving responsibilities, including the transfer of certain DEQ sections to other agencies, makes budget figures difficult to analyze. However, in 2009, the legislature appropriated more than $200 million to the DEQ's predecessor, the Department of Environment and Natural Resources. By 2017, that number had dwindled to just over $77 million.
In a blog post, Robin Smith, a former assistant secretary for the environment at DENR, wrote that those cuts have had lasting effects on the DEQ: about thirty administrative positions have been eliminated since 2015, and since 2009, three entire programs have been slashed.
Although the state House unanimously approved a bill in January to allocate more than $2.3 million to the DEQ for a new mass spectrometer and for several scientists to operate the new equipment, the Senate didn't take up the matter in a special session. Senate Republicans argued that scientific equipment could instead be borrowed from local universities and that research expenditures should fall on the companies responsible for the pollution rather than taxpayers. The bill will likely come up again when the legislature reconvenes next month for the short session.
DEQ officials acknowledge that their recording data could also use improvements. In the short term, they rely on simple plastic buckets to collect rainwater for their research on PFAs. The department plans to improve its accuracy by purchasing eight sophisticated rain collection tools, but each system costs roughly $6,500, and Chemours is only paying for half of them. The rest will fall on taxpayers.
Ferguson stressed that, compared to other states, North Carolina already has great potential to be a leader in the field of emergent contaminant detection. After all, the discovery of GenX would have never happened if North Carolina did not have superior research facilities in which to conduct experiments. But it's still difficult for scientists to screen for possible contaminants without knowing which chemicals they should be looking for.
Duke researchers say that monitoring equipment along the Rhine River, which serves as a source of drinking water for more than twenty million Europeans, could be a source of inspiration. At the Rhine's monitoring station, scientists collect data on emerging contaminants every day in order to identify larger trends. Sophisticated alarm systems also notify analysts when the concentration of dangerous chemicals surpasses a particular threshold.
Ferguson hopes to one day set up a similar system in North Carolina that could spot contaminants before they became a significant health issue, as in the case with GenX.
"GenX is one emergent contaminant, but we really should be thinking about this from a much more holistic standpoint," Ferguson explained. "So we propose the creation of what we would call the North Carolina Emergent Contaminant Observatory."
That plan would bring together state, federal, and academic actors to conduct research into how to best remove emergent contaminants from water systems. Ferguson says his colleagues have already discussed the possibility with state legislators and members of the DEQ and the EPA. So far, they're all on board, he says.
For now, though, Carey, of the Sierra Club, remains skeptical. "We've been disappointed and disheartened, and to a certain degree, people are angry that this seems to be a political vehicle at this point," she says. "The one agency that has been put in charge of protecting our drinking water has been cut over the last eight years."