The Ministry of Environment says it was only notified Wednesday afternoon of a spill last week at the Packaging Corporation of America’s mill in International Falls.
The M-O-E issued a statement about the spill only after inquiries earlier in the day by Acadia News.
The agency says between 2,000-3,000 gallons of sulphuric acid spilled into Rainy River last Wednesday.
The spill was neutralized and Minnesota Pollution Control Agency inspectors found no adverse impact to the river, but had not contacted Ontario authorities.
The M-O-E says it has made municipalities aware and will be coordinating with the mill to monitor potential long-term risks.
It also wants to review reporting protocols with M-P-C-A.
