top of page

U.S. Steel Projects Emissions Increases Following Pollution Reduction Project at Clairton Coke Works

Updated: Mar 25

Editor’s Note: The deadline to submit public comments regarding the U.S. Steel permits was 11:59 p.m. March 15.


Right now, the Allegheny County Health Department is seeking public comment on a draft installation permit for an upgraded Pushing Emissions Control (PEC) Baghouse at U.S. Steel’s Clairton Coke Works – and we need YOUR help to ensure it does what it is intended to do: Reduce emissions coming from the Mon Valley-based facility.


The deadline to submit formal comments regarding the upgraded piece of equipment – known as a PEC Baghouse for short – is March 15. 


But let’s back up for a minute and explain: A PEC Baghouse reduces emissions that result when finished coke is pushed out of an oven by collecting them with a hooded vent and running the emissions stream through a fabric filter to collect particulate matter.


Those who’ve been following the issue may recall that this facility upgrade was mandated as part of the controversial June 27, 2019, settlement agreement between U.S. Steel and ACHD related to ongoing air quality issues at the Clairton Coke Works. Specifically, that agreement required U.S. Steel to upgrade the PEC Baghouse for Batteries 13-15 and 19-20 at the facility.


U.S. Steel claims that the upgraded baghouse should collect particulate emissions with about 95 percent efficiency, as opposed to the 90 percent efficient existing PEC system. Here’s the issue, though: Despite this so-called “upgrade,” the PEC Baghouse will remain subject to the same limit of particulate matter per ton of coke produced. 


“In its application for the Installation Permit, U.S. Steel projects that the volume of coke it produces at Batteries 13-15 and 19-20 will increase substantially following the installation of the new PEC Baghouse,” GASP senior attorney John Baillie explained. “Unfortunately, this means the projected increase in production will outstrip the pollution control benefits of the upgraded PEC Baghouse.”


Here’s what you need to understand:


U.S. Steel projects that following the upgrade, particulate matter emissions from the baghouse will increase by 30.8 tons/year, and that sulfur dioxide emissions from the PEC Baghouse will increase by 43.4 tons/year.


The Allegheny County Health Department (ACHD) announced earlier this year that all eight air quality monitors in Allegheny County have met federal air quality standards for carbon monoxide, nitrogen oxide, ozone, and particulate matter (PM2.5, PM10). Even though air quality monitors in the county have measured attainment for particulate matter, they have not for sulfur dioxide, and the EPA has not yet determined that the county is in fact in attainment for PM2.5.


“When it reviews an application for an Installation Permit, ACHD must determine whether any increased pollution from the new source will impermissibly hinder attainment of the NAAQS,” Baillie explained. “ In nonattainment areas, this determination is made under what’s known as Nonattainment New Source Review regulations. These regulations apply if installation of the new source would cause a ‘net emissions increase’ that is ‘significant.’” 


Because the Nonattainment New Source Review regulations impose additional burdens on major sources of air pollution when they apply, operators will do what they can to avoid claiming that a project will cause a “net emissions increase” that is “significant.”


For context: A “net emissions increase” occurs if the projected actual emissions from the new source will exceed the baseline actual emissions from what it replaced. A “net emissions increase” is “significant” if it exceeds 10 tons/year of particulate matter or 40 tons/year of sulfur dioxide.


Notably, in calculating projected actual emissions, the Nonattainment New Source Review regulations allow a source to request a “demand growth exclusion.” 


This type of exclusion allows it to exclude the portion of the unit’s emissions following completion of the project that existing units could have accommodated that is also unrelated to the particular project, including all increased utilization due to product demand growth. 


We noted above that the projected actual emissions of particulate matter and sulfur dioxide from the upgraded PEC Baghouse at Clairton will exceed the baseline actual emissions by 30.8 tons/year and 43.4 tons/year, respectively.  


“By themselves, those increases would trigger application of the Nonattainment New Source Review regulations,” Baillie said.


However, U.S. Steel has claimed demand growth exclusions of 21.9 tons/year of particulate matter (equating to 71 percent of the projected increased emissions) and 4.2 tons/year of sulfur dioxide (equating to less than 10 percent of the projected increased emissions). 


The claimed demand growth exclusions reduce the projected emission increases that are purportedly attributable to the PEC Baghouse upgrade to 9.9 tons/year of particulate matter and 39.2 tons/year of sulfur dioxide – increases that are just below the threshold that would trigger the application of Nonattainment New Source Review Regulations.


“The bottom line is that U.S. Steel’s permit application does not explain why the same projected increased demand for the Clairton Plant’s products is responsible for 71 percent of the projected increase in particulate emissions from the PEC Baghouse, but only 10 percent of the projected increase in the PEC Baghouse’s sulfur dioxide emissions,” Baillie said. 


“Indeed, U.S. Steel’s permit application for the PEC Baghouse upgrade does not explain or document the demand growth exclusions that it has claimed in its permit application at all,” Baillie added. “It thus appears that U.S. Steel may have jiggered the numbers to avoid application of those regulations.”


This is where we are asking for YOUR help: We’re calling on all Allegheny County residents concerned about emissions from U.S. Steel’s Clairton Coke Works to let ACHD know that this is not acceptable. If U.S. Steel wants to claim demand growth exclusions for the PEC Baghouse upgrade project at the Clairton Plant, it needs to document or otherwise justify those exclusions. If it cannot do so, the PEC Baghouse project must comply with the NNSR regulations.


GASP is making it as simple as we can to make your voice heard on this issue with the below form, which will route your public comment about U.S. Steel’s Clairton Coke Works directly to ACHD. Use our included sample language and add your own:


Editor's Note: The deadline to submit a public comment has passed.

bottom of page