Lowell’s Duck Island Clean Water Facility will immediately stop receiving contaminated wastewater, called leachate, from a landfill in New Hampshire. Environmentalists have raised concerns that once the water is treated and released into the Merrimack River, it might still contain dangerous chemicals.

Dan Graovac, president of the Merrimack River Watershed Council’s Board of Directors, called this “welcome and fantastic news.”

“Public reaction to this was very swift and very strong,” Graovac said. “Our elected officials up and down the river have all been in touch with the Watershed Council and they reacted in unison across party lines that this is unacceptable.”

Lowell’s decision also comes after a front-page article inThe Boston Globe highlighted concerns that a group of man-made chemicals known as PFAS were found in high levels in the landfill and were not filtered out of the water during the treatment process. PFAS is used in many household items and has been found in almost all humans. However, emerging research has linked PFAS to a variety of serious health concerns.

In an interview with WGBH News, the City of Lowell suggested the environmentalists’ concerns were premature. However, a spokesperson said the city decided to stop accepting the wastewater out of an abundance of caution.

"I haven't seen any data. I'd like to see data,” said Mark Young, the executive director for Lowell's Drinking Water and Wastewater Treatment Utilities, before the decision to stop accepting the wastewater was made.

This month, Lowell will begin testing Merrimack River water for PFAS, upstream and downstream from the treatment plant. The Massachusetts Department of Environmental Protection (Mass DEP) said results should be available within a few weeks.

If testing from the river showed high levels of PFAS, then it should “absolutely” be addressed, Young said, but right now, he said he did not have any data to indicate it was a problem. He added that the drinking water treatment plant has the ability to filter out PFAS if it is an issue.

The MassDEP said in a statement that the communities downstream of the treatment plant — Andover, Lawrence, Methuen and Tewksbury — also have the ability to address PFAS contamination if it's found in their water.

One of the challenges is that, although PFAS has been link to numerous health concerns, the federal government has not set any legally enforceable limit for PFAS. Massachusetts is now in the process of establishing new drinking water standards.

A statement from Waste Management, which owns the New Hampshire landfill, highlighted that those Massachusetts standards will be for drinking water and not wastewater.

“There are no wastewater standards for these compounds at this time and when they are established, we intend to meet them,” the statement said. “In the meantime, we are in the process of evaluating treatment technologies to address these compounds.”

But the EPA has not approved a method for testing PFAS in wastewater, said Lowell's Mark Young.

Duck Island has accepted truckloads of the contaminated wastewater since 2012 and were paid five cents a gallon. The permit was recently reissued and allows for up to 100,000 gallons of runoff to be delivered each day. However, Lowell said the actual average is closer to 24,000 gallons a day.

Graovac, of the Merrimack River Watershed Council, said his organization will be looking for funding to test the river for PFAS as well as bacteria. However, he said, he’s not particularly concerned about the treated wastewater that already ended up in the river. “Fortunately, the amount that has been put in is small,” he said.

Correction: An earlier version of this story incorrectly referred to the Merrimack River Watershed Coalition. It is in fact the Merrimack River Watershed Council.