Heartland Corn Products, a southern Minnesota ethanol producer, has agreed to pay a $53,000 fine for a number of state environmental violations.

The violations were discovered when Heartland conducted its own environmental audit in 2018 after a change in management at the Winthrop co-op, according to the Minnesota Pollution Control Agency (MPCA)."The audit turned up many violations that in total exceeded the discretionary threshold for civil penalties," the MPCA said in a statement.

The plant had not been doing proper performance testing, record keeping and reporting on the operation and maintenance of its pollution control equipment. Also, Heartland had not fulfilled requirements for managing stormwater and dust on its property, as well as for handling hazardous waste and used oil, the MPCA said.

"However, MPCA officials credited the company's new management for voluntarily undertaking the audit knowing that penalties would probably result," the statement said.

Heartland could not be reached for comment.

The fine is the largest Heartland has received from the MPCA, with the previous high being a nearly $15,000 fine in 2002, MPCA records show.

Heartland Corn Products is the fourth largest of Minnesota's 18 operating ethanol plants, with annual production of 113 million gallons, according to the Minnesota Bio-Fuels Association, a trade group. Heartland, owned by its farmer members, employs about 50 people, its website says.