Core Summary

  • Environmental advocacy groups havesued the U.S. Environmental Protection Agency, alleging it failed to respond to a petition challenging the renewal of a clean air permit for the largest mill at U.S. Steel's Gary, Indiana, facility.
  • The plaintiffs—the Environmental Law & Policy Center, the Environmental Integrity Project, the Responsible Development Advocates for Gary, and the Northwest Indiana Just Transition Organization—seek a court order requiring the EPA to approve or deny theirpetition submitted on July 3, 2025.
  • The plaintiffs argue that U.S. Steel's Title V operating permit lacks sufficient monitoring and compliance provisions to ensure the plant can operate within specific air pollution limits. Under the Clean Air Act, the EPA has a 60-day deadline to respond to petitions. A spokesperson for the Environmental Law & Policy Center confirmed to Manufacturing Dive on Tuesday that, ten months later, the agency has still not acted on the petition.

In-Depth Analysis

This lawsuit comes as U.S. Steel seeks to strengthen its domestic operations under its Japan-based parent company, Nippon Steel.

Recently, U.S. Steel's board approved$475 million in fundingto install a quench-and-temper line at its Birmingham, Alabama, plant. The company also plans to investup to $2.5 billionin its Mon Valley Works facility in Pennsylvania and plans to restart the tin line at its Gary, Indiana, plant next year.

Meanwhile, Gary residents continue to pressure U.S. Steel to adopt technologies that reduce air pollution, improve worker health and safety, and extend the facility's lifespan. In late May, more than 120 people attended a town hall meeting where they expressed concerns that a significant portion of the$3.1 billiondesignated for Gary would go toward outdated coal-fired equipment.

"Environmental stewardship is a core value at U.S. Steel, and along with our more than 4,000 employees at the Gary Works facility, we remain committed to the safety of our communities," a spokesperson said in an email on Tuesday.

When asked about the environmental groups' air permit petition and its potential impact on the company's investment strategy, U.S. Steel declined to comment, stating it is not an active party in the lawsuit.

The U.S. EPA also declined to comment, citing the pending litigation.

In thecomplaintfiled in the U.S. District Court for the District of Columbia, the environmental groups argue that emissions of nitrogen oxides, volatile organic compounds, and hazardous air pollutants from the Gary Works facility exacerbate ground-level ozone pollution and adversely affect the health of nearby residents—such as increasing the risk of asthma, lung cancer, heart attacks, and strokes.

On April 29, 2024, they submitted public comments to the Indiana Department of Environmental Management regarding the draft renewal of the plant's clean air permit. The state submitted the proposed permit to the EPA for review on March 21, 2025, and issued the final renewal permit to the Gary Works facility on May 7, 2025.

On July 3, 2025, these organizations filed a petition urging the EPA to object to the permit. They argue that the permit lacks sufficient monitoring requirements to ensure compliance with particulate matter emission limits, Lake County opacity limits, and coal pulverizer limits. The organizations also claim that the permit lacks compliance monitoring, recordkeeping, and reporting requirements, as well as corrective action and maintenance plans, to ensure compliance with blast furnace limits.

"The EPA's inaction has hindered efforts to address our serious concerns and those of others about whether the Gary Works permit includes the monitoring and compliance measures necessary to protect public health," Max Lopez, deputy attorney at the Environmental Law & Policy Center, said in a statement.

According to the company's website, the Gary Works facility is U.S. Steel's largest manufacturing plant, with an annual capacity of up to7.5 million net tonsof steel.