BRUNSWICK COUNTY, NC (WECT) - Another unregulated chemical was found in water samples taken in Brunswick County, but the presence of it is 100 times lower than when water was sampled at one plant by the Environmental Protection Agency in 2015.
According to a release sent Friday afternoon, 1,4-dioxane was found in Brunswick County's raw and treated water samples taken at the Northwest Water Treatment Plant, which draws water from the Cape Fear River, on July 5. In raw water samples, 1,4-dioxane levels were listed at 1.3 parts per billion and levels were less than detectable (0.028 ppb) in the treated water.
Testing of water samples taken at the 211 Water Treatment Plant, which uses 13 wells to draw water from the Castle Hayne Aquifer, show the presence of 1,4-dioxane at 1.3 ppb in treated water.
Results from the Northwest Water Treatment Plant are 100 times lower than when water was sampled in 2015 as part of the EPA's Unregulated Contaminant Monitoring Rule (UCMR3).
Results from the 211 Water Treatment Plant are higher than the samples taken in 2015, but are still well below the EPA's noncancer adverse health effect advisory of 200 ppb, which is calculated for consistent daily exposure over a lifetime to the most vulnerable populations, like infants.
However, results from the 211 Water Treatment Plant are equal to a 3.7-in-a-million cancer risk level, according to the EPA's 1,4-dioxane technical fact sheet. This risk level was determined from animal studies. There are no U.S. regulatory maximum contaminant levels for 1,4-dioxane.
According to the EPA, parts per billion and micrograms per liter are equivalent to each other, and each form of measurement is equivalent to one drop in 50,000 liters or 13,208 gallons, of water.
"We are pleased with the results of the tests from the Northwest Water Treatment Plant as it shows that we effectively eliminated the 1,4-dioxane to undetectable levels," County Manager Ann Hardy said in the release.
In recent weeks, local and state agencies have focused mostly on testing for GenX, an unregulated chemical used in the production of Teflon at the Chemours Company in Fayetteville, and 1,4-dioxane wasn't included in Dr. Detlef Knappe's original report on chemical contamination in the Cape Fear River.
Friday's release stated that Brunswick County had no reason to suspect 1,4-dioxane in the wells drawing from the aquifer, and the county said it is working to locate and isolate the source of the chemical to determine appropriate corrective actions.
Brunswick County is also developing a plan for sampling of the source water as officials determine whether these results are a sampling anomaly. Staff is also working to determine why the number has changed from 2015 when the 211 Water Treatment Plant showed 1,4-dioxane at 0.04 PPB.