BLADEN COUNTY, N.C. (WECT) – The North Carolina Department of Environmental Quality has approved a permit for a granular activated carbon (GAC) water treatment system to remove some pollutants from the contaminated groundwater at the Chemours Fayetteville Works site.
A National Pollutant Discharge Elimination System (NPDES) permit is required anytime pollutants are discharged into water in the United States and are used to enforce the Clean Water Act, per the Environmental Protection Agency. After an initial period of 180 days, the limits will be 10 parts-per-trillion (ppt) for GenX, 10 ppt for PMPA and 20 ppt for PFMOAA. In other words, the removal needs to be over 99.9% effective.
“Currently, the contaminated groundwater flows untreated directly into the Cape Fear River. This project is designed to reduce the largest ongoing source of PFAS contaminating the river and reaching downstream water intakes and must be operational by March 15, 2023,” said the NCDEQ in a release.
The DEQ has also approved the design of a barrier wall, which would require monitoring and management of the contaminated groundwater during construction.
The NCDEQ explains the NPDES permit in more detail below:
The NPDES permit includes weekly monitoring upstream and downstream of the treatment system during barrier wall construction to track progress and efficiency. It also allows for an evaluation after one year to incorporate new data and further tighten limits if appropriate. The permit can also be reopened to add limitations based on new toxicity data, introduction of federal or state PFAS standards, and if another PFAS compound breaks through the treatment system more quickly than the three current indicator parameters
The massive remediation project is the largest of its kind to address PFAS. The system involves a mile-long underground barrier wall, more than 70 extraction wells, and the GAC treatment system to intercept and treat groundwater contaminated by years of pollution at the facility. The groundwater will be pumped and treated to ultimately remove an estimated 99.9% of PFAS compounds before being released into the river.