The US Environmental Protection Agency (EPA) and the US Department of Justice announced a modification to a 2015 consent decree today between the United States and state of Michigan and the Cleveland-Cliffs Steel Corporation (formerly AK Steel) to resolve Clean Air Act violations at the company’s Dearborn, Michigan, steel manufacturing plant.

The decree required the Dearborn plant to implement certain measures to address visible air emissions from the plant. Because these measures failed to bring the plant into full Clean Air Act compliance, the modification requires Cleveland-Cliffs to undertake additional extensive measures at a cost of more than $100 million, which are expected to reduce visible emissions from the plant, as well as curtail emissions of manganese and lead.

Breathing lead and manganese pollution can cause various, negative health effects, including impacts to the central nervous system. In addition, breathing lead pollution has been linked to impacts to kidney function, and to the immune, cardiovascular, reproductive and developmental systems in humans. In anticipation of the agreement, Cleveland-Cliffs has already performed much of the required work.

The modification requires replacement of the plant’s electrostatic precipitator (ESP) that removes particulate matter from exhaust gases that stem from the plant’s operations and thereby controls visible emissions. It also requires routine testing of the new ESP to assure compliance with applicable emission limits, certain operational parameters and regular monitoring for visible emissions.

The company will also pay a civil penalty of $81,380 to the State of Michigan for violating the state permit’s opacity, lead and manganese limits. Additionally, Cleveland-Cliffs will implement a state-law supplemental environmental project in which nearby residents will receive home air purifiers, at an estimated cost of $244,000. The facility is located in an area with environmental justice concerns according to data from EPA’s EJSCREEN tool.

There will be a 30-day public comment period on the proposed modification.