By Laura Hayes, Contributing Writer
SHREWSBURY — With a pilot program assessing the presence of hexavalent chromium in Shrewsbury’s water supply wrapping up, the town is about to start a second pilot program targeting PFAS.
“This is just continued effort in our focus in improving our public infrastructure for the benefit of the community,” said Town Manager Kevin Mizikar during a May 11 Board of Selectmen meeting.
According to the Centers for Disease Control and Prevention, hexavalent chromium is used in welding, chromate painting and electroplating. It can be harmful to the eyes, skin and respiratory system.
Hexavalent chromium had been detected in Shrewsbury’s Home Farm Water Treatment Plant wells. Three wells at the site were impacted, Water and Sewer Superintendent Dan Rowley said.
“We haven’t found it in all our well sites,” he clarified.
Between September and December, Shrewsbury’s pilot study was conducted by town water consultants Tata & Howard and sub-consultants AdEdge Water Technologies.
Two technologies were simultaneously piloted — a biottta® biological filtration system and an ion exchange filtration system — to remove hexavalent chromium. According to Rowley, the difference between the two is the ion exchange filtration would treat all of Shrewsbury’s flow, whereas the biottta® could be used at specific wells.
Rowley said both systems were successful in removing the hexavalent chromium.
Selectman Beth Casavant asked if hexavalent chromium could be found at wells in the future, even if it isn’t there at the moment.
Director of Public Works Jeff Howland said when the chemical was originally detected, all of the wells and finished water were tested. They determined that it was a “narrow plume” coming down Plantation Street toward the Home Farm wells.
“We’re confident that the hex chrome is isolated to the Home Farm well site,” Howland said.
As the pilot program wraps up, all of the wells are being tested, Rowley added.
Rowley said the consultants were reviewing the results from the pilot study and looking into operating and capital costs.
In the meantime, Paul Howard, co-founder of Tata & Howard, estimated that the upgrades might cost between $5-7 million.
Rowley said he expected that a report would be delivered to the selectmen in June.