NEW HANOVER COUNTY, NC (WECT) - Cape Fear Public Utility Authority officials said Friday they are trying to determine why levels of two compounds were higher in treated water than in the raw water at one of its treatment plants.
Two weeks ago, Dr. Detlef Knappe shared his most recent data on unregulated compounds in the water from the Sweeney Water Treatment Plant with CFPUA officials. Dr. Knappe's data showed the levels of PFO2HxA and PFO3OA were higher in the finished water supply as compared to the untreated water.
CFPUA officials said that staff is working with consulting firm Black & Veatch to determine the potential cause for the increase in levels in the treated water.
"One possibility is that compounds could be desorbing from existing carbon filters in the water treatment process," CFPUA stated in a release. "Sweeney Water Treatment Plant employs state of the art treatment technology, divided into several different phases of the treatment process. One phase is known as biofiltration — a process that uses carbon filters to adsorb organic material from the water. This process is one of the most important of the treatment processes. It is highly successful in removing the precursors to disinfection byproducts—substances that form when organic material reacts with disinfection chemicals. It is possible that these filters, while installed to fulfill a biofiltration purpose, have also been incidentally adsorbing per-fluorinated compounds over time. If the filters have become full, they could begin to desorb the compounds and release them into the water being treated through the plant."
CFPUA said its will send a second round of water samples to Dr. Knappe early next week for analysis.