North Carolina regulators have ordered the chemical company Chemours, spun off by DuPont in 2015, to take additional steps to prevent pollution from PFAS chemicals from entering the Cape Fear River—including construction of a 1.5-mile subsurface barrier wall and groundwater extraction system.

Under an agreement reached Aug. 13 with the North Carolina Dept. of Environmental Quality and environmentalists, the company that manufactures chemicals such as Teflon and freon must reduce the level of toxins by 99% at four identified “seeps” that account for more than half of the contaminated groundwater reaching the river.

In 2018, Chemours said it would spend more than $100 million at its Fayetteville, N.C., plant to control air and wastewater emissions from PFAS chemicals, known as per- and poly-fluoroalkyl substances, and also referred to as "forever chemicals" because they do not break down easily in the environment.

PFASs were discovered in 2017 in the Cape Fear River, the source of drinking water for Wilmington, N.C., and two counties. DuPont informed state officials of testing that indicated the chemicals had seeped into groundwater under the plant soon after production began in 2002. 

Results of studies by seven state universities released last month showed high PFAS levels in the river, according to an Aug. 3 report in the Port City Daily newspaper.

The agreement is an addendum to a 2019 consent order that ended process wastewater discharges from the company’s Fayetteville plant and required reducing air emissions by 99.99%.

Chemours must have an interim measure to filter at least 80% of PFAS chemicals from the first seep completed by April 2021.

The permanent mitigation, the subsurface barrier and extraction system to get to 99% removal in groundwater, must be completed by March 2023. The company also must install filters in contaminated streams flowing into the river to remove at least 99% of PFAS pollution.

A capture-and-treat system must be installed to remove 99% of PFASs from onsite storm water that is adding residual pollution to the river.

The agreement contains penalties for missing construction deadlines including $150,000 for not completing the barrier wall followed by $20,000 a week until it is finished.

A $500,000 fine will result from failure to meet the barrier wall’s 95% loading goal in the initial demonstration and an additional $100,000 fine for failure to meet any of four remaining demonstrations.

Under the 2019 consent decree, Chemours developed a plan to demonstrate the maximum PFAS reduction from the plant that can be achieved in two years.

The new agreement will be filed with the Bladen Country Superior Court after a 30-day comment period.

North Carolina Attorney General Josh Stein on Aug. 10 launched an investigation into the extent and causes of PFAS contamination in the state, including the number of water bodies affected and sources of release.

PFAS chemicals are used as additives in nonstick coatings and in fire suppression foams, among other things.