CFPUA has expressed concerns to state regulators “about the apparent ineffectiveness of measures Chemours has taken so far to reduce the mass loading (see below) of its PFAS into the Cape Fear River.”
In a letter submitted February 3 to Sheila Holman, Assistant Secretary of the N.C. Department of Environmental Quality (NCDEQ), CFPUA cited:
- Operational failures at treatment installed in fall 2020 intended to reduce PFAS entering the river from Old Outfall 002 at Chemours’ industrial site. Chemours was compelled to install the treatment as part of its obligations under a Consent Order with the state and Cape Fear River Watch. According to a Notice of Violation NCDEQ issued to Chemours on January 26, Chemours’ treatment system at old Outfall 002 “was not properly designed to meet the requirements of the Consent Order to capture dry weather flow and treat it to at least 99% removal efficiency for the indicator parameters, GenX and PFMOAA. This design failure is shown, for example, by the inability of the treatment system to properly manage sediment loading, resulting in multiple days where the system failed to capture dry weather flow and periods where the system was completely shut down.”
- Operational failures at treatment installed in mid-November that was supposed to reduce PFAS from Seep C, one of four seeps that leak groundwater with high levels of Chemours’ PFAS into the Cape Fear River. On three separate occasions since that installation, Chemours has notified regulators and downstream water users that high river levels had overwhelmed the Seep C treatment and impaired operation.
“For CFPUA and its customers, Chemours’ failures are particularly concerning given that, according to Chemours’ own data, Old Outfall 002 and the four seeps (designated A, B, C, and D in the Consent Order) are responsible for more than 75 percent of the mass loading of Chemours’ PFAS into the Cape Fear River,” CFPUA’s letter states. “Our analysis of data from our own monitoring of PFAS in raw water point to the failure of measures at Old Outfall 002 and Seep C to reduce PFAS mass loading in any meaningful way. Table 3+ mass loading has barely budged since October 1, when treatment at Old Outfall 002 was to begin operation; mass loading of PFMOAA has actually increased.”
CFPUA has requested information about what is being required of Chemours to correct these failures, as well as results of tests that document the effectiveness of the treatment measures Chemours is implementing to reduce PFAS mass loading.
In the meantime, work is proceeding to add eight new granular activated carbon filters at Sweeney Water Treatment Plant to effectively treat Chemours’ PFAS in raw water from the Cape Fear River. The $43 million project is expected to be complete by early 2022. CFPUA believes Chemours, not our customers, should pay for the filters and has filed a lawsuit in federal court to recover these and other costs.
What is “mass loading”?
CFPUA regularly monitors PFAS levels in water we draw from the Cape Fear River. It’s important to note that PFAS concentrations may fluctuate depending on volume of river flow: higher flows typically result in lower PFAS concentrations, even if the amount of PFAS that Chemours is contributing to the river remains the same. One measure that overcomes this shortcoming is called “mass loading,” which estimates the actual contribution in pounds per day to the river regardless of the river flow rate. This illustration may help explain how mass loading works and its relationship to concentration: A teaspoon of sugar in a 12-ounce glass of iced tea will have a much higher sugar concentration than a teaspoon of sugar in a gallon of iced tea. The “mass load,” however, is the same in both: one teaspoon.
CFPUA staff have been calculating PFAS mass loading in the river at our raw water intake to monitor what effects, if any, Chemours’ mitigation measures are having on the amount of PFAS that Chemours is contributing to the river. So far, our data indicate no meaningful change in the mass loading. In fact, for one of Chemours’ compounds – PFMOAA – the mass load has actually increased since October 1, 2020, when treatment Chemours was forced to install at Old Outfall 002 supposedly became operational.
Graphs showing CFPUA’s mass loading calculations for Table 3+ PFAS compounds (those linked by regulators to Chemours) and for PFMOAA are included with the letter to NCDEQ.