Wells are for emergency use only, but concentration of contaminants up 260% in one sample, compared with last year
Levels of toxic perfluorinated compounds, also known as PFAS, have surged in several groundwater monitoring wells in New Hanover County recent data show, prompting state regulators to investigate potential sources.
All of the wells are for emergency use only, said Vaughn Hagerty, spokesman for the Cape Fear Public Utility Authority, and are not providing water for public consumption at this time. The utility also has taken the Seaspray and Sea Pines wells out of service.
The Peedee Aquifer is the source of the well water.
As part of routine monitoring, the Cape Fear Public Utility Authority tested water from the groundwater monitoring wells in April. The utility presented the findings at its May board meeting and notified the NC Department of Environmental Quality about the increases. CFPUA regularly reports sampling data on its website.
The utility and DEQ provided year-to-year comparisons to Policy Watch, dating from 2019 when well monitoring began (see map, right). Here are the recent figures from 2021:
- Sea Pines, 694 ppt
- Seaspray, 462 ppt
- Elkmont, 46 ppt
- Queens Point, 69 ppt
Known as “forever chemicals,” PFAS persist in the environment, particularly in groundwater and drinking water. Exposure to these compounds has been scientifically linked to many health problems, including thyroid disorders, liver damage, a suppressed immune system, low-birth weight, decreased fertility, high cholesterol and kidney and testicular cancers.
There at least 5,000 types of PFAS. They are found in hundreds of consumer products, including microwave popcorn bags, fast food containers, nonstick cookware, as well as compost and some firefighting foams.
These compounds are widespread in the environment, not only in North Carolina, but nationwide and globally.
PFAS are not regulated in drinking water, although the EPA is making final determinations to regulate two types of the compounds in drinking water, PFOS and PFOA.
The EPA and DEQ have issued a health advisory goal of a maximum of 70 parts per trillion (ppt) for PFOA and PFOS combined in drinking water.
Rick Bolich, groundwater resources section chief for the state Division of Water Resources, told Policy Watch in an email that levels of PFOA and PFOS in the wells were below that threshold.
However, the EPA and DEQ have previously advised against drinking water with levels of any individual PFAS above 10 ppt.
Bolich said the agency is analyzing the data for trends and to identify potential sources. Since newer testing methods allow labs to detect more types of PFAS, DEQ is also investigating whether that could have factored into the increases.
The division “intends to re-sample some of the wells with those objectives in mind,” Bolich said. It will also attempt to sample private water supply wells, but can only do that with permission from the well owners.
For decades, Chemours, which is 100 miles upstream, discharged PFAS into the Cape Fear River, the drinking water supply for Wilmington. The river also feeds the groundwater and aquifer system.
Chemours no longer discharges wastewater from its manufacturing processes into the river. A 2019 consent order between the state, the company and Cape Fear River Watch required Chemours to build a treatment system to remove residual contaminants from entering the river.
However, that system has failed. In March, state regulators fined Chemours nearly $200,000 for failing to meet conditions of the Consent Order and violations related to the treatment system.
An aquifer storage well in Wilmington could also contribute to the contamination, Hagerty said.
In 2017, the Cape Fear Public Utility Authority pumped water from the Sweeney water treatment plant into an aquifer storage well to keep finished drinking water that could be used during times of high demand. The utility suspended the project after it learned that it had unknowingly contaminated the aquifer well because water from the Sweeney plant was contaminated with GenX and other PFAS from Chemours.
That storage well remains contaminated.
Coastal hydrology is complex: Tides, soil types, groundwater withdrawals, and flooding or droughts can affect the movement and pathways of water beneath the surface. PFAS can also travel long distances in the air, according to a paper issued last month by scientists from UNC Wilmington and UNC Chapel Hill, which are part of the NC PFAST Testing Network.
The utility has installed an advanced low-flow membrane technology at the Richardson water treatment plant to remove PFAS. April 6 sampling data showed “no detections” of PFAS in treated water at Richardson.
At the Sweeney treatment plan, testing last month showed the presence of 14 types of PFAS, totaling 74 ppt. The utility previous installed equipment to reduce the concentrations; a $46 million project that will include new granulated activated carbon filters is scheduled to come online next year to remove the compounds.