A water sample taken in Sept. 2019 from the Sanford Sewage Treatment Plant that discharges into Deep River uncovered high concentrations of per- and polyfluoroalkyl substances (PFAS), according to documents from North Carolina’s Department of Environmental Quality (DEQ).
The sample contained perfluorooctanesulfonic acid (PFOS) at 1,000 parts per trillion (ppt), which is greater than the U.S. EPA’s health advisory of 70 ppt for drinking water, reported the Carolina Public Press.
Since 2014, the Division of Water Resources has been sampling for 1, 4 dioxane in the Cape Fear River Basin after seeing elevated concentrations.
Between July and Sept. 2019, the DEQ required 25 utilities in the basin to test for 19 or more different types of PFAS at their wastewater treatment plants. The data was made public in mid-January.
The highest level of total PFAS detected was in Sanford at a concentration of 4,026 ppt in September. Burlington saw nearly 2,296 ppt in a sample from August. 19 of the 25 recorded total PFAS levels were above 100 ppt at different periods in the reporting cycle, according to the Carolina Public Press. No data was provided for one of the 25 utilities, Columbus County.
It is unclear where the contamination came from, according to officials with the DEQ and Scott Siletzky, Sanford’s water reclamation administrator.
The DEQ’s plan is to identify the amount of the chemicals flowing into the sewer treatment plants and then determine which industries are responsible for putting them there, reported Carolina Public Press. As part of the second phase, industrial dischargers are being asked to monitor for releases of PFAS and 1,4 dioxane.
The state has taken actions against Greensboro and Reidsville, which the DEQ cited for violating their pollution permits due to failure to notify the state and downstream water utilities about large releases of 1,4 dioxane in a timely manner. The citations were issued because the chemical showed up downstream in the town of Pittsboro’s drinking water, according to the Carolina Public Press.
Currently, no action has been taken against Sanford, even though PFOA and PFOS could have flowed downstream and impacted the levels in Sanford’s drinking water. The PFOS contamination could be coming from firefighting foam, according to Siletzky.
Siletzky did not notify downstream utilities because he “wouldn’t know how to do it.”
Sanford is voluntarily undergoing at least another six months of monthly monitoring and evaluation of the potential sources of PFAS.
The DEQ has not taken action against Burlington. Instead, the Southern Environmental Law Center filed a notice of intent to sue Burlington over PFAS contamination on behalf of the Haw River Assembly, for violating the Clean Water Act and the Resource Conservation and Recovery Act.
The data does acknowledge that test results for the other 24 wastewater treatment plants showed concentrations of PFOA and PFOS that would not exceed the EPA health advisories. Test results for the other 22 sewer plants in the monitoring program were not anticipated to cause levels of 1,4 dioxane to exceed the EPA’s health advisory of 35 parts per billion in drinking water.
