The Sierra Club said Monday that it has filed an intent-to-sue notice against Minnesota Power, alleging that the utility has committed nearly 13,000 violations of the Clean Air Act at three coal-fired power plants in northeastern Minnesota.
The group alleges that the utility’s data show its Boswell, Taconite Harbor and Laskin plants have violated soot standards more than 10,000 times over the past five years. It also says the utility committed hundreds of violations of permit requirements related to the operation of pollution-control equipment, including mercury controls.
The environmental group is using a provision of the Clean Air Act that allows citizens to sue to seek enforcement of the law. It says it will sue unless the matter is resolved before the 60-day notice period ends.
The notice names Duluth-based Minnesota Power, parent company Allete and Sun Prairie, Wis.-based WPPI Energy, which owns a share of the Boswell plant.
Amy Rutledge, a spokeswoman for Minnesota Power, said the Sierra Club’s allegations were off-base.
The Sierra Club is using data on “opacity,” a measure of how much light can pass through a plant’s plume, as an indicator of particulate levels. But Rutledge said opacity is not a pollutant and can be caused by several factors, such water vapor in a stack on a cold day.