Randy Delorey says the Pictou County mill is still expected to meet the government's requirements by May 30, otherwise its industrial approval can be suspended or cancelled.
Mill manager Bruce Chapman has said the company contracted to install a new recovery boiler precipitator informed the mill last week they will no longer be installing the equipment.
Delorey says his department was informed when the contractor backed out but he does not know why it happened.
He says Northern Pulp has not requested an extension on the deadline.
In January, the province issued an industrial permit for Northern Pulp that introduced new environmental regulations for its mill in Pictou County.