HAMMOND, Ind. (AP) - U.S. Steel will pay a $600,000 civil penalty and $630,000 to reimburse various federal agencies for costs and damages after one of its plants discharged wastewater containing a potentially carcinogenic chemical into a tributary of Lake Michigan, federal and state officials said Monday.

The U.S. Justice Department said those terms are contained in a consent decree filed Monday in federal court in which U.S. Steel promised to take steps to improve its wastewater processing monitoring system to resolve alleged violations of the Clean Water Act and Indiana law.

The April 2017 spill at a U.S. Steel manufacturing and finishing plant into the Burns Waterway near Portage, Indiana, contained hexavalent chromium, a toxic heavy metal that the U.S. Environmental Protection Agency has said might be carcinogenic if ingested. The Justice Department said the plant experienced a rupture in an expansion joint in wastewater pipes, discharging untreated wastewater into the tributary.

"Today's settlement with U.S. Steel appropriately penalizes the company for last year's wastewater spill, recoups the government's response costs and other losses, and requires significant actions by the company to prevent toxic spills like this from occurring again," Jeffrey H. Wood, the acting assistant attorney general for the Justice Department's Environment and Natural Resources Division, said in a statement.

As part of the agreement, U.S. Steel will reimburse the EPA $350,000 for its response costs and the National Park Service more than $250,000 for its response costs and damages resulting from weeklong beach closures along the Indiana Dunes National Lakeshore, the Justice Department said.

U.S. Steel said in a statement the steps it's taking include installing a new wastewater piping system and completing repairs to a containment trench; implementing new spill notification procedures.

The company said the consent decree also resolves violations from another wastewater discharge last October containing a less toxic form of chromium.

The settlement is subject to a 30-day public comment period and final approval by the court.

The EPA has said hexavalent chromium is used in a variety of industrial processes, including steelmaking and corrosion prevention, and as a pigment in dyes, paints and inks. It's also found in ash from coal-fired power plants.

A case involving the chemical was made famous by the 2000 film "Erin Brockovich," which was based on a utility's disposal of water laced with hexavalent chromium in unlined ponds near Hinkley, California. That disposal method polluted drinking water wells and resulted in a $333 million settlement.