Corn Plus, a major ethanol cooperative in southern Minnesota, was charged Friday with reporting that its pollution control equipment was working properly in late January when company officials knew it was not.

The alleged felony offense took place Jan. 27, less than a week after the U.S. Department of Agriculture awarded Corn Plus a grant of $128,658 from its Bioenergy Program for Advanced Biofuels.

The alleged offense also took place while the company was on probation for a previous environmental law violation.

Corn Plus, which produces 49 million gallons of ethanol a year 35 miles south of Mankato in Winnebago, pleaded guilty two years ago to a misdemeanor for negligently discharging polluted water into Rice Lake. U.S. Magistrate Judge Jeanne Graham placed the company on three years' probation in October 2009 and ordered it to pay a $100,000 fine, plus a $50,000 "community service payment" to a critical habitat program run through the Minnesota Department of Natural Resources.

Corn Plus also paid $861,000 to settle a dispute with the Minnesota Pollution Control Agency last year over alleged water quality violations that took place from 2006 to 2008. It paid a $200,000 civil penalty and agreed to spend at least $691,000 on plant improvements designed to protect the environment.

According to the latest charge filed in federal court in Minneapolis, Corn Plus falsely certified that it was complying with its permit requirements knowing that its pollution control equipment was allowing excessive discharges into the air, a violation of the Clean Air Act. The company was charged by "felony information" rather than indictment, which generally indicates that a plea bargain will follow.

Corn Plus referred a reporter to its attorney, Dustan Cross, who did not respond to a message seeking comment.

A USDA spokesman, reached late Friday, said no one was immediately available to comment on the grant.

Dan Browning • 612-673-4493