Chalky residue on the cement section of the river (copy)

While the Hoosic River was running clear Wednesday, a white chalky residue remained on the banks of the river behind North Adams City Hall.

NORTH ADAMS — Waste from Specialty Minerals turned the Hoosic River white Tuesday, but authorities have not reported any environmental impacts.

The state Department of Environmental Protection said Thursday that it has not found any fish kills.

“No other impacts have been reported,” a DEP spokesperson said in an email. Authorities will monitor the river for a week, the DEP said.

Industrial waste from Specialty Minerals leached into the Hoosic River on Tuesday, turning the water milky white as it flowed from the company’s Adams location and into North Adams and to the Vermont border.

The company stopped operations and said it self-reported the discharge of calcium carbonate.

“It is an inert, non-toxic and natural form of calcium carbonate also known as chalk or limestone,” Michael Landau, director of corporate communications for the company, said in an email. “The mineral will create a white or cloudy appearance when dispersed in water as was the case in the Hoosic River.”

Specialty Minerals reported that the discharge was caused by a “process upset,” according to an email from the DEP. In a statement sent Thursday, the company said it “has been conducting an investigation, with the support of the MassDEP, to identify the root cause of the release.”

A person first reported the leak in an email just after 11:36 a.m., and the company reported it at 1:11 p.m., according to the DEP.

When asked about how much calcium carbonate was discharged and for more information on what caused the problem, Landau responded in an email: “The investigation is ongoing in close coordination with the MassDEP, and we will start-up the relevant operations at our site following the DEP’s guidance.”

Greta Jochem can be reached at or 413-496-6272.


Greta Jochem, a Report for America Corps member, joined the Eagle in 2021. Previously, she was a reporter at the Daily Hampshire Gazette. She is also a member of the investigations team.