MAYSVILLE – Officials here said Thursday that firefighting foam was the likely source of the man-made compounds detected earlier this week in the town’s drinking water supply.
Town officials had switched from the Maysville well to Jones County Water as the town’s source of drinking water on Monday after testing revealed the presence of the unregulated compounds, which are colorless, tasteless, odorless and otherwise undetectable in water without specialized equipment.
During a special meeting of the town commission called to discuss the detection of per- and polyfluoroalkyl substances, or PFAS, in the samples from the town well, researchers from Duke University and North Carolina State University and an engineer were connected to the meeting via internet call to discuss their findings.
Lee Ferguson, an environmental analytical chemist at Duke, said the samples were taken as part of a statewide monitoring project to better understand the occurrence of PFAS and similar compounds in drinking water supplies. The PFAS Testing Network had analyzed a sample from the Maysville well May 7 for 55 types of PFAS and detected a combination of perfluorooctanoic acid, or PFOA, and perfluorooctane sulfonic acid, or PFOS.
Ferguson said the chemical signature or fingerprint of detected compounds in Maysville’s water was consistent with aqueous film-forming foams used in firefighting.
“We cannot say definitively that firefighting foam is the source of this contamination without doing some additional analysis by high-resolution mass spectrometry,” Ferguson told meeting attendees via Skype, adding that such analysis was happening.
Ferguson said the compounds detected did not include GenX but were “legacy compounds” and that analysis completed could not determine how long ago the contamination occurred. But there were indications of compounds phased out during the early 2000s.
“It’s anyone’s guess how long this has been in the water,” said Detlef Knappe, professor of civil, construction and environmental engineering at N.C. State.
Maysville is one of only two water systems of the 60-70 systems tested so far to receive notices of exceedance, along with the Orange Water-Sewer Authority, which was a different source of contamination that was already known to officials there.
Ferguson said samples from the Wilmington area are still being analyzed.
“I’m afraid I have to say that yes, your sample, so far, is an outlier,” Ferguson said in response to an attendee’s question.
Ferguson said he collected a sample from the Jones County Water system on Thursday for analysis, finding no detectable levels of compounds for which the water was tested.
“That water should be free of PFAS compounds,” Ferguson said.
Ferguson, answering a question from an attendee regarding health implications, said available data for indicate there are risks from exposure to elevated levels of the compounds.
Knappe said health effects include toxicity to the immune system and links have been shown to certain types of cancer, such as testicular cancer. The compounds build up in the body over time, primarily in the blood, he said.
“One reason why these chemicals are of concern at these very low levels is that they have very long half lives in the human body,” Knappe said.
Town officials pledged transparency and full public disclosure regarding issues with the water supply.