top of page

Recent Air Quality Standard Amendment Will Further Limit Mercury Emissions at U.S. Steel Facility

Updated: Sep 14, 2022

U.S. Steel’s Braddock-based Edgar Thomson Works is one of 11 integrated iron and steel manufacturing facilities in the country to be subject to amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAPs) that were finalized recently by the U.S. Environmental Protection Agency.

These amendments didn’t just come out of the blue: Section 112 of the Clean Air Act directs the EPA to categorize sources of hazardous air pollutants (HAPs) and develop NESHAPs for them in order to minimize or eliminate emissions from sources in those categories.

Here’s how it works procedurally: Within eight years of the promulgation of a NESHAP, EPA must review (and if necessary, revise) the standards to incorporate any new and improved “practices, processes, and control technologies” in the source category. 

The EPA must also determine whether the emissions allowed under the NESHAPs still pose an unacceptable risk to the public health or environment (after incorporating any new and improved practices, processes, or control technologies), and if they do, revise the standards to further limit emissions.

The recent amendments, which are a result of such technology and residual risk review, will add limits on emissions of mercury from major sources in the iron- and steel-making industry, effective July 13, 2021. 

Airborne mercury causes harm to wildlife and to the human brain and nervous system, especially in fetuses and young children. Mercury can be present in emissions from the iron- and steel-making process when a facility charges the iron or steel it produces with automotive scrap if mercury-containing switches and devices have not been removed from it. 

The Edgar Thomson Works’ Title V Operating Permit currently does not include an emission limit for mercury but does prohibit the facility from using “#2 automotive scrap” (a term that does not appear to be defined by the permit) in any charge. The Edgar Thomson Works is otherwise allowed to use up to 40,000 pounds of “galvanized scrap” (also apparently undefined) per charge.

“Going forward, the Edgar Thomson Works will either be subject to a stringent emission for mercury or need to certify that none of the automotive scrap it uses contains mercury,” GASP Senior Staff Attorney John Baillie explained.

The recent amendments will also eliminate exemptions to the emission limits imposed by Subpart FFFFF for startup, shutdown, and malfunction events. This change was spurred by a 2008 federal appeals court decision – Sierra Club v. EPA – that determined such exemptions violate the Clean Air Act.

“That means that startup, shutdown, and malfunction exemptions for sources in the category will cease to have effect beginning Jan. 11, 2021,” Baillie said. 

bottom of page