PFAS discharges from Kalamazoo's wastewater treatment plant are now under the state limit of 12 parts per trillion for surface water.
That's down from a high of about 53 parts per trillion last summer.
The improvement comes after the state installed a carbon filtration system in a former plating plant. The plant was dumping large amounts of PFAS chemicals into the plant's treatment system.
PFAS is a class of chemicals associated with health problems.
Scott Dean is a spokesman for the Michigan Department of Environmental Quality. Dean calls it "an early win," in the state's effort to find sources of PFAS contamination, and clean them up.
"Because it's really important to break this cycle of PFAS in the water system," he says.
Dean says PFAS is a huge emerging problem in the state, so there's much more work to be done.
He says the state paid for the filtration system because there was no longer an owner.
"We do work very agressively to track down responsible parties and hold them to account," says Dean. "In this case the Production Plated plant went bankrupt many, many decades ago."
The state also connected the city of Parchment to Kalamazoo's drinking water and wastewater treatment systems, after high PFAS levels were found in the city's three wells.
Dean says the source of Parchment's PFAS contamination is likely a former paper mill.