Groundwater

The Department of Environmental Quality directed Chemours to begin conducting sampling of 14 groundwater monitoring wells that are at the Chemours facility and not used for public purposes in July 2017. Thirteen of 14 industrial wells at the company’s Fayetteville Works facility had detections of GenX in violation of state groundwater standards. The wells tested are used for environmental monitoring at the facility and are not a source of drinking water. Based on those test results, the state departments of Environmental Quality and Health and Human Services notified local officials and initiated plans to start testing the private wells of residents nearest the facility on Sept. 15, 2017. The Consent Order signed in February 2019 directed Chemours, among other things, to determine the extent of the PFAS contamination related to the Fayetteville Works site and provide replacement water supplies to affected residents. DEQ will continue to direct Chemours to expand its sampling until the edge of the contamination plume is found.

Chemours' On-site Groundwater Sampling Sites

Tab/Accordion Item

    If you have been notified that your private well showed concentrations of GenX compounds above the state's provisional health goal (140 ppt) for drinking water, above 10 ppt for any individual PFAS listed in Attachment C to the Consent Order, or above 70 ppt for combined quantifiable concentrations of PFAS listed in Attachment C to the Consent Order, then you are qualified to receive bottled water. If you have questions about bottled water delivery, please call (910) 678-1101.

    The N.C. Department of Environmental Quality and Chemours tested granular activated carbon (GAC) systems installed at private residences in the Chemours Fayetteville Works area beginning in 2018 for a period of one year. Results from the study showed GAC systems to be effective at removing GenX and other PFAS from the water if properly maintained. 

    Maintenance is key

    • GAC systems must be maintained to be effective.
    • Filters can become a source and increase levels of PFAS in the water if they are not regularly changed.
    • The Consent Order requires Chemours to do the following to ensure GAC systems are working properly:
      • Test GAC systems quarterly between the filters to check for breakthrough of PFAS compounds. This allows data to be collected to determine the appropriate time for canister changeout while the second canister assures homeowners are protected.
      • Change GAC filters when levels of any PFAS compound reaches 100 ppt between the filters.

    GAC Sampling Data
    Department staff tested the untreated (before the filter) and treated (after passing through the filter) well water approximately every two weeks during this time. The GAC Pilot Study included six test sites for one year; however, a homeowner at one site left the study before the end of the study period. Only five sites were sampled for the full year of the pilot study. Samples were collected at each site for 33 per- and polyfluoroalkyl substances or PFAS compounds.

    Indoor water sampling at GAC system locations

    A law firm, representing a resident who is participating in the GAC pilot study, contacted the division Sept. 12 and provided sample results showing elevated levels of PFAS in water from the hot water tap inside a GAC pilot study home (location 71). DEQ sampled water from the indoor hot water tap at the five pilot study locations to see if they were having the same issue. Those results did not reflect similar issues as in Location 71. In response to residents’ concern, DEQ investigated and found a water softener connected after the GAC filters. After the water softener was cleaned out, results did not show elevated levels of PFAS in the finished water. To prevent this from happening at other residences, the finished water is tested at homes to make sure that systems are removing PFAS from drinking water.  In addition to that residence, DEQ resampled four other residences from the GAC pilot study. Results will be posted after the study concludes.

    In 2019, the N.C. Department of Environmental Quality began testing the Kinetico reverse osmosis (RO) systems being installed by Chemours in private residences in the Chemours Fayetteville Works area. Preliminary tests show the systems are effective at removing PFAS from the water.  

    Unlike GAC water treatment systems, which must be tested to determine when a filter change is necessary, RO systems slow down and eventually stop working to prevent breakthrough. Indicators on the systems let homeowners know when the system is nearing shutdown and they need to call for a filter replacement. The RO systems include a sediment removal and carbon polishing cartridge which will need to be exchanged approximately every 1 to 1.5 years based on average household drinking water usage rates. The primary RO membrane will need to be replaced every three to five years based upon the amount of water used, which is tracked by the number of sediment and carbon polishing filter changeouts.

    The department is testing the untreated (water before the filter) and treated (water after passing through the filter) well water approximately every month during the initial RO pilot study. Testing will also include systems nearing shutdown that require a filter change.

    Samples were collected at each site and tested for 35 per- and polyfluoroalkyl substances or PFAS compounds. The RO Pilot Study includes four test sites.

    Additionally, two new RO filter systems were approved by DEQ in October 2020 for use in locations where the other Kinetico RO systems do not fit. These systems will also be tested for PFAS removal efficiency.

    DEQ maps

    Area maps

    The N.C. Department of Environmental Quality performed a limited sediment characterization study in 2021 due to experimental design concerns with a 2020 Geosyntec Sediment Characterization Study funded by Chemours that included sampling in areas where per- and polyfluorinated substances (PFAS) were not likely to be found and using an analytical method that was not sensitive enough to detect several PFAS unique to the Chemours Fayetteville Works Site (Table 3+ compounds). These experimental design issues were thought to result in non-detect Table 3+ PFAS concentrations for several sediment samples in the Geosyntec study. Once the experimental design concerns were addressed in the NCDEQ study, a much higher percentage of samples had detectable Table 3+ PFAS compounds.

    The NCDEQ sediment characterization study detected Table 3+ compounds in more than 90 percent of samples as compared to the Geosyntec study, which detected Table 3+ compounds in 33 percent of samples. Legacy and other PFAS (some of which are present at, but not unique to, the Fayetteville works site) were measured with a sufficiently sensitive analytical method. As a result, legacy and other PFAS were detected in 100% of samples in both the 2020 Geosyntec study and the current DEQ sediment characterization study. 

    Read the study.

    View the Sediment Study Results Table in Excel.

    • Sampling Results
    • Note: This study does not meet the minimum sample guidance for a N.C. Department of Health of Human Services’ fish consumption study.
    • Note: The samples were collected prior to periods of active fish feeding and growth, and may not be representative of concentrations that would be found at other times of the year or in other fish species.
    • Note: Routine fish tissue collections typically occur at the end of the fish growing season, which in North Carolina is late summer to early fall when the potential uptake of contaminants would be expected to be at their highest yearly concentration.

    Post-Hurricane Florence Sampling Plan (Oct. 11, 2018) 

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