Cumberland, Rhode Island popped up on a list of cities and towns that have unsafe levels of the chemical perfluorooctanoic acid, or PFOA. It’s used to make Teflon. It turns out those levels have dropped significantly in the town over the past year.
Now they're within a safe threshold.
And that's good news. The toxic chemical is linked to cancer, thyroid diseases and complications during pregnancy. Rhode Island Public Radio environmental reporter Ambar Espinoza has more on what we know and don't know about how this chemical got into Cumberland's drinking water.
"It's part of EPA's process to try to figure out what ought to be regulated in drinking water in the future," said June Swallow, chief of the Center for Drinking Water Quality at the Rhode Island Department of Health. "And that consists of evaluating health risks of a contaminant and also evaluating whether that contaminant occurs in drinking water at levels of concern in the country."
Last year, in the most recent round of testing in Rhode Island, the chemical PFOA showed up in one water sample from the Cumberland Water Department, which serves more than 22,500 people.
At that time, the EPA’s health advisory limit for PFOA was 400 parts per trillion. Cumberland’s water sample detected PFOA at 81 ppt.
But, the health department still asked Cumberland to monitor that particular water system by sampling it every quarter, even though as far as both offices knew at the time, the levels fell well below the advisory level. Water Superintendent Chris Champi agreed to the quarterly sampling.
“We wanted to take a proactive approach to see a) what the source of PFOA was in the water and b) create a baseline for what the actual level is in the water,” said Champi.
Fast forward to this May. The EPA revised its advisory level from 400 ppt down to 70 ppt. That’s a steep drop, and put Cumberland on the list of towns that exceeded the threshold - barely.
The PFOA levels have dropped since then. They’re down to the low 20s. (The first quarterly results detected PFOA at 24 ppt and 25 ppt; the second quarterly results at 21 ppt and 22 ppt.) Those are levels considered unsafe by state standards in Vermont, but well below the new EPA standard.
But where the PFOA is coming from is still a mystery. Champi's team had done repairs on that well system about a week or so before drawing water samples for the EPA survey. They used plumber’s tape, also known as Teflon pipe tape. He said that could have contributed to the problem.
“However, we didn't have hits at our other well sites which go through a very similar procedure to what happened at that site during regular maintenance, so I would discount that as being a source [of PFOA]."
So, what could the source be? In Merrimack, New Hampshire, high PFOA levels were traced to nearby factories that have made products with the chemical and to contamination from landfills. Champi said there aren't any similar industries or landfills near the well, but is looking into whether fire departments have put out fires with a foam that has PFOA.
“We're lucky with that [water] source because it only supplies about 9.5 percent of the water for our total system,” said Champi. “And as it enters the distribution system it's immediately blended with other water from other sources which all were absent for PFOA."
Johnathan Berard, the Rhode Island director of Clean Water Action, is pleased the health and Cumberland water departments took steps to be proactive about this issue by initiating quarterly sampling and publishing its results in the Consumer Confidence Report mailed out to residents this year.
“It's also refreshing to see a government agency doing the right thing, you know and acting in the best interest of their customers and of Cumberland residents," said Berard.
The Cumberland Water Department will continue to monitor that well. Should PFOA levels go up again, the water superintendent says they’ll look into treatment options to remove PFOA or take that well out of service until they figure out the source of the problem.
This report comes from the New England News Collaborative. Eight public media companies coming together to tell the story of a changing region, with support from the Corporation for Public Broadcasting.