NC State scientists: GenX will be in Cape Fear River, tap water for years to come; health effects need more study

By: - April 18, 2018 1:22 pm

Left to right: NC State scientists Jane Hoppin, Detlef Knappe and Nadine Kotlarz presented the results of a tap water study conducted in Wilmington. While none of the samples showed levels of GenX above the state’s health advisory goal, the tap water is not free of it, nor other fluorinated compounds. (Photos: Lisa Sorg)

Left to right: NC State scientists Jane Hoppin, Detlef Knappe and Nadine Kotlarz presented the results of a tap water study conducted in Wilmington. While none of the samples showed levels of GenX above the state’s health advisory goal, the tap water is not free of it, nor other fluorinated compounds. (Photos: Lisa Sorg)

The Cape Fear River is damaged, contaminated by decades of human malfeasance, negligence and ignorance.

For those reasons, NC State University scientists told a crowd of 75 New Hanover County residents last night, it will be years before their tap water is completely free of GenX and other fluorinated compounds.

Scientists from the university’s Center for Human Health and the Environment released the results of a month-long tap water study conducted in Wilmington in November and early December of last year. In addition to 198 tap water samples, researchers led by scientist Nadine Kotlarz collected blood and urine from 300 people who get their water from the Cape Fear Public Utility Authority. Study participants also filled out a health questionnaire to help inform researchers of any links between exposure and disease.

“We’ll have the first human data on what’s in the body,” said Jane Hoppin, who lead the Human Population team. “That’s the question we’re trying to answer because there is no data on how long the chemical stays in the body.”

Of the tap water samples, 194 were taken from homes that are served by the utility’s Sweeney plant, which gets its water from the Cape Fear River. Four samples were taken from homes served by the utility’s Richardson plant, where groundwater is its source.

Scientists also analyzed the samples for 17 other fluorinated compounds, both those known and newly identified, such as GenX. Levels of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) were also below the EPA’s drinking water standard of 70 parts per trillion. However, the cumulative effects of these compounds is still unknown.

While the blood and urine analyses is not yet complete, tap water results showed that none of the samples of Sweeney plant customers exceeded the state’s provisional health goal of 140 parts per trillion. The range was non-detect to 100 ppt, with an average of 45 ppt. (To protect the privacy of the participants, scientists didn’t reveal individual results, but discussed them in general terms.)

Kotlarz noted that the utility, which routinely monitors for GenX, showed levels of 29 ppt in treated water at the Sweeney plant during the testing period.

Samples from the Richardson plant did not detect any of these compounds.

“Each sample is a snapshot of what was in the water at that moment,” Kotlarz said. Concentrations can vary based on those entering the Sweeney plant from the river.

And scientists could not pinpoint concentrations of several compounds that were part of the study because they did not yet have the analytical tools to do so. It’s expected that they will be able to do that type of analysis with the blood and urine, Kotlarz said.

Fluorinated compounds that showed low levels in water may be higher in blood. “The blood can provide more information about long-term exposures,” Kotlarz said.

There are no human health studies on the effects of GenX. However, a study of 45,000 adults who were exposed to GenX’s precursor, C8, in Parkersburg, WV, showed significant increases in thyroid disorders and high cholesterol levels. Hoppin said the research team would be analyzing these health effects in this study, and will ask some recipients to return for a second round of health questions.

On this slide, the groundwater source is the Richardson treatment plant, operated by the Cape Fear Public Utility Authority. The Sweeney plant uses water from the Cape Fear River (right), and showed detections of GenX.

Levels of GenX in the river and drinking water have decreased “dramatically,” said NC State scientist Detlef Knappe, since Chemours stopped discharging contaminated wastewater from its Fayetteville plant upstream. Other contaminants originating from industries farther upstream that discharge into the Haw River also contribute to the pollutant load. For example, several years ago Knappe detected high concentrations of 1,4 dioxane in the Haw River and Pittsboro’s drinking water. Pittsboro has since installed an activated charcoal system to help reduce those levels.

“The Cape Fear is not pristine when it enters Chemours,” Knappe said. But in addition to the fluorinated compounds in the Haw, they are also coming from the plant.

Since it’s unlikely that these compounds will be eliminated from the drinking water, the scientists advised residents concerned about the contamination to buy under-sink reverse osmosis systems. In an unfunded study conducted last year, Knappe led undergraduate researchers in testing several types of removal systems. Reverse-osmosis significantly decreased the contamination levels in drinking water. The cost of an under-sink system ranges from $200 to $1,000, plus maintenance and replacement of the filters. (The cost creates an economic and environmental justice issue for low-income individuals and households, for whom $200 is equivalent to nearly three days’ gross pay at minimum wage.)

A slide presented by the scientists showed that under-sink reverse osmosis systems were the most effective and least expensive option for reducing contaminants in drinking water.

Other systems did not remove the contaminants as well as reverse-osmosis, or they presented their own set of problems. Most activated carbon block filters removed the contaminants, but the filters must be changed regularly. And these carbon systems don’t have a way to monitor the filters’ performance. “You’re kind of flying blind,” Knappe said.

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Brita filters, for example, did not remove 1,4 dioxane. And whole-house filtration systems can present their own problems. Those systems can remove chlorine from the water — added by the treatment plant to kill bacteria and other pathogens from the river — and leave people vulnerable to infections. They are also every expensive, well over $1,000.

Even though fluorinated chemicals are no longer leaving the Chemours plant via the company’s wastewater, they are still entering the air, where the contaminants then settle on the soil and can enter the river. Groundwater and river sediment are also contaminated. And ultimately, much of that pollution winds up in the Cape Fear and in the drinking water supplies of those living downstream.

“The contamination of land and groundwater will persist for decades,” Knappe said.

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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.