Drinking water distributed by the Richardson Water Treatment Plant continues to show no detections of PFAS compounds, according to recent monitoring conducted by Cape Fear Public Utility Authority.
Richardson, which provides water to the second-largest of CFPUA’s three drinking water-distribution systems, serves customers in northern New Hanover County, including Murrayville, Wrightsboro, Porters Neck, and parts of Castle Hayne and Ogden. Its source is groundwater drawn from wells tapping the Castle Hayne and PeeDee aquifers.
On March 27, CFPUA sampled finished water at Richardson, two wells serving it, and an emergency well that currently does not provide drinking water as part of an effort to monitor potential movement of PFAS compounds that have been detected in and near our Aquifer Storage and Recovery (ASR) well. Results are available here.
The ASR well was designed to store finished drinking water from the Sweeney Water Treatment Plant in the Upper PeeDee Aquifer. During periods of high demand, that water could have supplemented CFPUA’s normal water supply.
In 2017, CFPUA suspended a pilot program to inject water into the ASR after GenX from Chemours was detected in water from the well. Subsequent analysis has found several other PFAS compounds there and in nearby wells, the overwhelming majority of which are found only downstream of Chemours’ Fayetteville Works chemical plant, about 100 miles up the Cape Fear River from Wilmington.
In late March, CFPUA tested drinking water from Richardson and three wells, two of which provide water to Richardson. While no PFAS compounds were detected in finished water from Richardson, they were found in water from the wells.
For the two Richardson wells, the totals of all PFAS compounds were 36 parts per trillion and 65 ppt. No PFAS was detected in samples of finished water drawn the same day at Richardson.
Richardson WTP contains state-of-the-art membrane technology recognized as one of the best available filter technologies. CFPUA had tested water from Richardson for GenX in 2017 and found none.
The third well tested in March had a total PFAS concentration of 180 ppt. This well is meant as an emergency source for the distribution system served by the Sweeney Plant, CFPUA’s largest system serving about four-fifths of our customers. This well is not in operation or otherwise contributing to CFPUA’s drinking water system.
Not enough information is available to determine whether the PFAS found in the water from the three wells migrated from the ASR. Groundwater typically migrates relatively slowly – perhaps 15 feet a year – and the wells are 2 to 3 miles from the ASR.
The majority of the PFAS compounds in the wells are found only downstream from Chemours’ plant and make up a significant portion of the PFAS that CFPUA routinely finds in raw river water. These compounds are among those singled out in “Attachment C” of a recently approved consent order between the state and Chemours. The consent order includes provisions requiring Chemours to pay for filter options for owners of private wells where these compounds have been detected above 10 ppt singly or 70 ppt collectively.
As with past results, these have been shared with the North Carolina Department of Environmental Quality. CFPUA also has asked NCDEQ for guidance and assistance in addressing the groundwater affected by Chemours’ PFAS.