Greensboro investigating source of chemicals found in water supply

GREENSBORO, N.C. -- "I live in Greensboro, drink the water, raise my children on it, my grandchildren now as well. I care about it," Greensboro Water Resources Department Director Steven Drew. "These substances should not be in our environment."

Drew is talking about the perfluorooctanoic and perfluorooctanesulfonic acids, or PFOS and PFOA, found in the city's drinking water. In early 2015, the city found one site in the watershed that tested above a recommended healthy level. Water Resources has been testing several sites ever since and has never seen readings above that recommended level, which has also been dropped to a lower threshold. That single test was an outlier, but did concern the city about where these chemicals come from, and Drew wanted to learn more.

"In the drinking water business, you always want to remove contaminants at the source if we can," Drew said.

So where do PFOS and PFOAs come from? Turns out the man-made chemicals are related to a lot of things like teflon that create a "non-stick surface." They're in pizza boxes, non-stick skillets and even in the lining of a microwave popcorn bag.

The chemicals have also been in foams used by fire departments and airports doing fire safety training. When the foam gets on the ground, it eventually runs off or washes away, finding it's ways into our waterways. Water Resources believes that may be the source of these chemicals in Greensboro water, highlighting several sites around the airport and the greater watershed where fire department training has taken place in the past.

Since learning about these chemicals, there is still a lot we don't know about them. Fire departments have begun using substitute compounds in their training foam that don't contain PFOS or PFOA. Drew says Piedmont Triad International Airport is also actively working with his department to rid the chemical from any practice.

"I have full faith and confidence in all the partners that we're working with, in the upper watershed," Drew said. "Everyone is taking this very seriously."

The chemicals are carcinogens, which means they have been linked to, in high doses of exposure, possibly causing cancer or tumors. The levels in the Greensboro water supply aren't even close to high enough where that would be a factor; the drinking water is safe.

Think of it as 20 to 40 drops of these chemicals in a tank the size of two Olympic-sized swimming pools. The one test that was above the recommended level at the time was the equivalent of 92 drops.

"You really have to take it in every day at above a permissible exposure limit for a really long time, so that's why I want to emphasize this was one anomalous hit, and we're way below any health advisory," Drew said.

The department has highlighted 19 sites in the watershed it will be testing thoroughly over the next six months, and will rotate to incorporate different sites depending on new research and data. They're also working on a pilot project which would allow them to partially break down the chemical at the Mitchell Treatment plant, but that would require time and funding. The main goal is to identify the sources and minimize the exposure, even if the amounts are currently harmless.