Utility wants new limit for mercury releases to Lake Michigan

MILWAUKEE (AP) — A utility company wants to increase the amount of mercury it’s permitted to release into Lake Michigan from a coal-burning power plant in suburban Milwaukee.

The Milwaukee-based utility We Energies is seeking state regulators’ approval for a plan to dispose of as much as 4.1 parts per trillion of mercury from its Oak Creek power plant into Lake Michigan on any given day. That would be about three times more than the 1.3 parts per trillion threshold that’s considered safe for wildlife, Wisconsin Public Radio reported.

The request was the subject of a recent public hearing held by the Wisconsin Department of Natural Resources. More than 100 people then came out to express opposition to the plan.

Brendan Conway, We Energies spokesman, said new limits wouldn’t pose a health risk to humans or wildlife.

“We are not asking to be asked to be treated differently than anyone else along the lake,” Conway said. “Other permitees along Lake Michigan have received similar or higher mercury variances. People should also understand this variance we are talking about is allowed by the EPA and the DNR so this is not an imminent public health risk.”

The utility has seen its average amount of mercury emitted into the lake creep up, hitting an average of 1.26 parts per trillion a day over the past five years.

Both the department and We Energies said they don’t believe the utility will dispose of 4.1 parts per trillion of mercury more than once or twice a year.

“Mercury is a difficult pollutant, there is no way to sugar coat it,” said Jason Knutson, a wastewater section chief at the department. “Based on our experience, we are not aware of any treatment technology that is able to achieve the 1.3 parts per trillion water quality standards. Faced with that, we ask ourselves what is the best way to realize reductions to improve wastewater quality.”

The department has granted variances for other wastewater plants along Lake Michigan, including plants in Kenosha and Racine, allowing for emissions of 3.0 and 5.8 parts per trillion per day, according to Knutson.

The state requires plants that are granted variances to develop a pollutant-minimization plan. Knutson said the department will continue gathering information and public comments before deciding whether to change the utility’s permits.