Chatham County

Duke to study PFAS contamination in Pittsboro. How to protect your home drinking water

Duke University

Heather Stapleton was called to Robeson County in 2017 to test the water for contaminants that might be causing kidney diseases.

One of the contaminants in question was PFAS — perfluoroalkyl and polyfluoroalkyl substances — a group of chemicals found in household products, food packaging and firefighting foams.

Stapleton, a researcher at Duke University’s Nicholas School of the Environment, tested the Robeson water and then tested her own water at home as a control.

What she found changed the scope of her future research and made her buy a water filtration system for her house:

The levels of PFAS in her home’s water from Jordan Lake were much higher than in Robeson County.

PFAS in Pittsboro

Since then, studies have found PFAS levels in the lake and across the Triangle. Concentrations of over 70 parts per trillion, the EPA health advisory level, have been found in the Haw River near Pittsboro.

On Aug. 15, the town agreed to begin notifying residents of the possible contamination in their drinking water. There are about 4,000 residents in Pittsboro.

Town Commissioner Brett Wilson Foley said the town is trying to remove the chemicals.

“It’s not something that we are required to do, but we are doing it because we care about the people of Pittsboro,” she said.

The town also stressed that while the EPA does have a health advisory for the chemicals, they are still unregulated.

In an email, Pittsboro Town Manager Bryan Gruesbeck said, “The Town continuously seeks improve its raw water treatment processes and outcomes.” The town’s water treatment plant has earned five consecutive N.C. Area Wide Optimization Awards, he also noted.

PFAS contamination is a growing concern nationwide.

On Thursday, Pennsylvania approved $3.8 million to treat PFAS in drinking water.

Similarly, Wisconsin Gov. Tony Evers recently issued an executive order to create a PFAS action plan for the state. He had already proposed an enforcement standard of 20 parts per trillion, well below the federal advisory level.

Current Research

Duke and NC State University researchers have been testing 12 spots on the Haw River for PFAS contamination every Monday from Jordan Lake to Burlington. While Stapleton declined to discuss the findings, she said they had identified some “hot spots” along the river.

The higher concentration of PFAS may be partly due to drought earlier this summer, she said, but she doesn’t think that’s the leading cause.

Researchers will also be testing PFAS levels in the blood of some Pittsboro residents and comparing it with levels in the river. This will help researchers understand of how much PFAS stays in the system of a resident drinking Haw River water.

Another study that will be starting soon at Duke will expose rabbits to Pittsboro drinking water to see if it harms their offspring.

An NIH study in January found pregnant women exposed to PFAS had a higher risk of preeclampsia, a condition with symptoms like high blood pressure and the swelling of hands and feet.

According to the University of Michigan, PFAS may also affect the growth, learning, and behavioral development of children and increase the risks of certain cancers.

Once finished with the studies, Duke and N.C. State researchers hope to provide policy recommendations for the town and the state.

haw river.jpg
Duke researchers collecting water samples in the Haw River in July, 2019. They are collecting samples from 12 spots on the river to test for PFAS contamination. Dr. Kateri Salk-Gundersen Duke University

Filtration systems

Stapleton will be publishing a study soon on filtering out PFAS in the home.

She tested water in Pittsboro, Durham, Raleigh, Cary, Apex and Chapel Hill.

The best form of filtration is a reverse osmosis system, she said. These can run from $200 to $400 and are the only effective system for combating PFAS. Stapleton installed one in her own home after finding the contamination in 2017. The filter must be replaced annually, which costs between $100 and $200.

The system goes under the sink and can be installed in a few hours.

“Unfortunately reverse osmosis systems are expensive, so they’re not an economically viable option for some people,” Stapleton said. “So that’s why there’s a lot of tension trying to create technologies for the drinking water plant. The goal is to stop the chemicals before they get to anybody’s home.”

Systems like a refrigerator filter collect some of the chemicals but must be replaced very often.

Activated carbon systems, such as a faucet-mounted Brita filter, can filter out the chemicals fairly well, but high concentrations of PFAS that have collected in the system can break loose into the water if it gets overly saturated, she said.

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Trent Brown covers the Town of Cary and other odds and ends. He graduated from the University of North Carolina at Chapel Hill in 2019 and is a Collegiate Network fellow.