LUDINGTON, Mich. (AP) — Operators of a 63-year-old coal-fired passenger ferry that carries people and cars across Lake Michigan between Wisconsin and Michigan have made the necessary environmental improvements to keep the vintage vessel in service, U.S. regulators announced Thursday.

The 410-foot SS Badger launched in 1952 can carry 600 passengers and 180 vehicles. It’s the last coal-fired steamship operating on the Great Lakes and normally runs from May to October. It is scheduled to resume service Friday between Ludington, Mich., and Manitowoc, Wis.

The U.S. Environmental Protection Agency said inspectors this week confirmed that Lake Michigan Carferry Service Inc. “has taken all the steps necessary to permanently stop the discharge of coal ash” into the lake.

In September 2013, the EPA had given the Badger’s operators until this year to stop dumping ash into the lake. Operators have spent about $2.4 million on an onboard system to move ash from the ship’s four boilers to four retention bins on the car deck, the EPA said in a statement.

“The Badger car ferry is now in compliance with the Clean Water Act and will no longer discharge coal ash to Lake Michigan,” EPA regional Administrator Susan Hedman said in a statement. “EPA is pleased that we were able to find a solution that protects Lake Michigan and preserves jobs along the Michigan and Wisconsin shoreline.”

Previously, ash was transported from the boiler to an onboard retention area, mixed with Lake Michigan water and discharged in a slurry into the lake. The ash will be sold for use in cement-making, according to Chuck Leonard, vice president of Lake Michigan Carferry.

The Badger was built to the standards of its day, which once allowed trash and sewage of all lake vessels to be jettisoned overboard, Chuck Cart, chief engineer on the Badger for 19 years, said in January. It’s been modified as new standards have come into place, he said.