WILMINGTON — A North Carolina State University research team is testing water in New Hanover and Pender counties after tests indicated potentially dangerous compounds could be leaching out of utility filtration devices even after discharges had ceased upstream, the Wilmington Star News reported Tuesday.
Detlef Knappe, who was part of a team that wrote a 2016 study identifying GenX and six other perfluorinated compounds in the lower Cape Fear River, recently said a pair of associated compounds had persisted in finished drinking water during late June and July even as their levels dropped in raw water.
That could indicate compounds have become trapped in the carbon or microbes over time and are leaking into the cleaner water as it passes through. In the Sweeney Water Treatment Plant’s finished water, the compounds PFO2HxA and PFO3OA were found at levels of 1,170 parts per trillion (ppt) and 778 ppt, respectively, during the week of July 24 even as the level of GenX dropped to 70 ppt.
Now, both Cape Fear Public Utility Authority (CFPUA) and Pender County Utilities have asked Knappe to test water samples to determine whether the levels of all the chemicals, including the Nafion byproducts that have received attention in recent weeks, have fallen. Knappe also found elevated levels of the chemicals in question in the Pender plant’s finished water, albeit at lower levels than Sweeney’s.
Jim Flechtner, CFPUA’s executive director, said Knappe’s testing will go hand-in-hand with the utility’s continued effort to understand what kind of filtration can best handle the emerging contaminants.
A key question for CFPUA is whether the conditions from the June and July samples have persisted in the river. The raw water samples indicated levels of GenX-related compounds had “dramatically” dropped since late June.