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WATCHDOG REPORT: PA Regulators’ Struggle to Implement Clean Air Act Requirements for Regional Power Plants Continues

Today, we want to take you back to 2008, when the U.S. Environmental Protection Agency (EPA) revised the National Ambient Air Quality Standards (NAAQS) for ozone.  

The revision to that standard triggered an obligation for all major sources of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in ozone nonattainment areas to submit determinations that they have Reasonably Available Control Technology (RACT) in place to limit their emissions, which cause ozone pollution.  

Because the 2008 revision to the ozone NAAQS was the second such revision to trigger an obligation to perform RACT determinations, the determinations that it triggered are referred to as RACT II.  

They are submitted to state air pollution regulators like the Pennsylvania Department of Environmental Protection (DEP) and Allegheny County Health Department (ACHD), and if approved by them, are further submitted to EPA for final approval and inclusion in the applicable State Implementation Plan (or SIP for short).  

EPA’s Final Rule implementing the 2008 NAAQS for ozone required states with designated nonattainment areas to submit revisions to their SIPs to include RACT II determinations within 24 months of a nonattainment designation, and to require sources subject to the RACT II requirement to implement RACT II within five years of a nonattainment designation.  

All areas of Pennsylvania were designated as non-attainment for the 2008 ozone standard on July 20, 2012.  

“That means that DEP should have made RACT II determinations for all major sources in Pennsylvania by July 20, 2014, and those sources should have implemented RACT II by July 20, 2017,” GASP senior attorney John Baillie explained.


If you are looking at those 2008 and 2012 dates and asking yourself, “But what do deadlines matter?” we hear ya. Because just last week, EPA published a proposed rule that would disapprove RACT II determinations made by one now-shuttered coal-burning power plant in our region (the Homer City Generating Station) and two still-active coal burning power plants in our region (the Conemaugh and Keystone Generating Stations) - all three of which are major sources of NOx emissions.   

Yes, we also blogged about the harm resulting from these power plants’ sulfur dioxide emissions last week.  

“EPA’s proposed disapproval means that the three power plants still have not implemented the RACT II requirement that was triggered by the 2008 ozone NAAQS revision,” Baillie said.

In a nutshell, in its disapproval EPA found that DEP (and the power plants) failed to justify why the plants’ NOx emission rates were the lowest reasonably achievable, given that emissions data for the plants showed they could (and often did) achieve lower rates of NOx emissions.  

“The apparent problem here is that for cost reasons, the plant operators do not want to control NOx emissions at all times using what’s known as selective catalytic reducers that are already installed at the plants,” Baillie explained. “DEP was poised to let them, however, EPA would not allow it.”

If finalized, EPA’s proposed disapproval will require that either:  

  1. DEP explain and justify why lower NOx emission rates are not feasible despite the three power plants’ having achieved them when they operated their selective catalytic reducers; or 

  2. revise the RACT II determinations for the power plants to lower their emission limits for NOx to meet the lower rates that they achieved when operating their selective catalytic reducers.  

“Remember, all of this was supposed to have been over and done with by July 2017 at the latest; the regulators’ failure to get their acts together resulted in six-and-a-half years’ of ozone pollution that should have been prevented,” GASP Executive Director Patrick Campbell said.

Editor’s Note: You can send a message to the regulators that it is well past time to make these power plants use their emission controls at all times to reduce ozone pollution. Members of the public are invited to comment on EPA’s proposed rule by March 22, 2024.  

You can submit comments to EPA, identified by Docket ID No. EPA-R03-OAR-2024-0047 at or via email to

GASP continues to follow this issue closely. Stay tuned, we’ll keep you posted as the process proceeds.

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