DURHAM — Coastal communities don’t need to worry too much about hexavalent chromium in their drinking water, but there are other contaminants to watch out for.
This is according to statements Duke University professor of Earth and ocean science Dr. Avner Vengosh gave to the News-Times Wednesday in an interview.
Dr. Vengosh is one of several researchers who will provide updates and information at 10:45 a.m. Wednesday on threats to drinking water in North Carolina. Duke University is hosting the event, titled “Safeguarding the Water We Drink,” at the Duke University communications building at 614 Chapel Drive in Durham. Four Duke University faculty and one scientist from NCSU will provide updates and background on threats to drinking water sources in the state.
In addition to Dr. Vengosh, the scientists providing the updates and information include:
- Duke University associate professor of civil and environmental engineering Dr. Lee Ferguson
- Duke University Dan and Bunny Gabel associate professor of environmental ethics and sustainable environmental management Dr. Heather Stapleton.
- Duke University clinical professor of law Ryke Longest.
- NCSU S. James Ellen distinguished professor of civil, construction and environmental engineering Dr. Detlef Knappe.
Dr. Vengosh told the News-Times his part of the discussion will focus on two issues: coal ash contamination and hexavalent chromium contamination.
According to the Environmental Protection Agency, hexavalent chromium is an odorless and tasteless metallic element that may pose health risks if levels in drinking water exceed EPA standards. Coal ash, meanwhile, can contain contaminants such as mercury, cadmium and arsenic that, if left unregulated, may contaminate waterways, ground water, drinking water and the air.
Dr. Vengosh said evidence of coal ash has been found in a lake near Wilmington, and coal ash contamination is also possible in other lakes near the coast.
“There’s still much to do to protect people in North Carolina from coal ash,” he said.
However, hexavalent chromium is much less prevalent in coastal drinking water supplies, according to Dr. Vengosh. While levels have been exceeding EPA standards in wells in the Piedmont region in eastern North Carolina, the geology is different and wells aren’t as deep.
While chromium may not be a major concern for coastal communities, salinity is a different story. Dr. Vengosh said a study done “many years ago” on the Outer Banks showed excess salinity in drinking water, but it wasn’t because of the ocean but a longer-term, geological process.
A second significant risk to coastal communities’ drinking water is directly tied to salinity levels. Dr. Vengosh said older domestic community wells use chemicals, like chlorine, to purify their water. However, sometimes this can result in the disinfecting chemicals combining with salt in the water to create a disinfection byproduct that can be toxic.
Dr. Vengosh said coastal communities concerned about the chance of their drinking water being contaminated by these byproducts need to perform frequent testing. If evidence of a byproduct is found, they need to change their disinfection method.
“There are pros and cons in each (disinfection) method,” he said. “It depends on the circumstances (which one is best for a community).”
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