Levels of two compounds remain high in treated water at Sweeney plant

WILMINGTON, NC (WECT) - While levels of two unregulated compounds in the Cape Fear River have dropped considerably since June, data also shows they haven't dropped as much in treated water at the Sweeney Water Treatment Plant.

According to the Cape Fear Public Utility Authority's Friday afternoon update, Dr. Detlef Knappe, an NC State researcher who is studying the local water supply, emailed CFPUA on Thursday about ongoing water testing at the Environmental Protection Agency lab in Research Triangle Park.

Data shows estimated levels of PFO2HxA and PFO3OA, which are structurally similar to GenX, in the Cape Fear River have dramatically dropped since late June.

However, the levels of the compounds, while still trending downward, have not dropped as much in Sweeney's treated water.

CFPUA said the information has been distributed to the NC Department of Environmental Quality, the NC Department of Health and Human Services, UNCW faculty who are helping with the study and CFPUA's consultants at engineering firm Black & Veatch.

"We have asked these experts to weigh in on the results and prioritize trying to determine the cause," CFPUA said. "We would like to be careful to note that this test data appears to be from earlier this summer, and though definitely of interest, may or may not represent current conditions (with respect to quantities in today's water). That too is something we are trying to determine."

CFPUA, the DEQ and EPA continue to test raw water from the Cape Fear River as well as treated water in an effort to confirm whether Chemours has stopped or reduced discharges of unregulated chemicals into the river at its Fayetteville Works site.

CFPUA said it has taken deliberate steps to address two critical issues: unregulated chemicals in the river and the utility's ability to treat for them.

Those steps are:

  • Working with researchers at UNCW to identify and quantify compounds in the river that could affect drinking water, paying special attention to compounds that Knappe detected in his original 2016 study. This work is expected to be complete in mid-2018.
  • Contracting with Black & Veatch, which also designed the Sweeney Water Treatment Plant, to find solutions to protect water at its source, treating it and delivering it to homes and businesses.
  • Working with Black & Veatch to test different materials to find out whether CFPUA's filter system at the Sweeney plant could be upgraded to remove various compounds. Granular activated carbon has proven effective at other plants in filtering compounds such as those detected in the river. Preliminary results should be available within six months.

CFPUA Director Jim Flechtner said Friday the utility is doing all it can to give its customers the best product.

"We are always concerned about providing the best possible water we can," Flechtner said. "We will take this information, and make sure we design the next step in the treatment process for our plant with the information. If we can, then we will certainly filter it out."

Flechtner added he hopes the news will help the utility better understand what is in the water.

"Our efforts with the researchers at UNCW will answer one of the big questions that comes up here," he said. "What else is in the river, and what does it mean to us as the consumers of the drinking water? We are getting to those answers, and that will help us design the best solutions to filter the water even further."

Read Knappe's email in the PDF below and note that ppt stands for parts per trillion. NCDHHS established a health goal for GenX at 140 ppt.

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