Image from 2023 Blast Furnace Casthouse Emissions Control System Evaluation Report When discussing major air polluters in Allegheny County, U.S. Steel’s Mon Valley Works (composed of the Clairton Coke Works, Irvin Works and Edgar Thomson facilities) is among the first to come to mind. And for good reason: The Clairton Coke Works has been in the news for perennially polluting air in the Mon Valley and beyond for YEARS, with mounting enforcement actions issued by the Allegheny County Health Department for everything from hydrogen sulfide exceedances to pushing violations. But Edgar Thomson’s impact on Mon Valley ambient air quality cannot (and should not) be ignored. Operations at the facility have largely gone under the radar since a high-profile 2022 consent decree reached by the U.S. Department of Justice (DOJ), EPA, ACHD, and U.S. Steel that addressed waning compliance. Until now. As part of our watchdog work, GASP staff researched the history of Edgar Thomson’s air quality violations, revisited the terms of the consent decree, and made public records requests to help shed light on what required operational, equipment and maintenance changes have been made, what’s still in the works, and what’s still up in the air. The four-part series you are about to read is months in the making and includes information gleaned from online research and scores of documents obtained through the Right to Know process. While the high-profile settlement agreement was finalized in December 2022, the story of Edgar Thomson’s descent into noncompliance with air quality rules began years earlier. So, we need to rewind all the way back to 2016: Donald Trump had just been elected to his first term as President of the United States. Brexit was making international headlines, and right here in Pittsburgh, the Edgar Thomson Works came out of the gates that year with a spate of air quality violations that spanned the entire year. U.S. Steel racked up enforcement actions for everything from violating opacity limits to blowing past fugitive emissions standards. Here’s a look at one of those enforcement actions: After an employee complaint spurred an OSHA investigation, U.S. Steel was also fined $170,000 for how it handled asbestos abatement at Edgar Thomson. From the OSHA report: That pattern of noncompliance continued into the new year, with ACHD issuing the first of many notices of violation to U.S. Steel just four days into 2017. The issue? Inspectors noted visual emissions opacity violations at the facility - an issue U.S. Steel would be dinged for again in February. Air quality troubles continued for the company in April of 2017, ACHD deemed U.S. Steel’s annual certificate of compliance for 2016 as non-compliant. Not only did U.S. Steel got tagged with three more notices of violation for visible emissions violations and for violating other terms of its Title V operating permit. The problem regulators flagged? For one, that U.S. Steel failed to properly maintain and repair inoperable rotary valves necessary for the proper operation of Edgar Thomson’s air pollution control equipment on both Feb. 4 and Feb. 17, 2017. U.S. Steel continued to rack up enforcement actions for violating local air quality rules as well as the terms of its Title V - with ACHD noting two such infractions in May, six more in June, and another two in July. This flurry of activity culminated with a Nov. 17, 2017 announcement that made headlines here in Pittsburgh and beyond: That EPA and ACHD had issued a joint notice of violation against U.S. Steel for myriad violations related to blast furnace and BOP Shop operations – among other things – at Edgar Thomson from 2016 through July 2017. An ACHD press release regarding the NOV explained, “The nature of the violations includes excessive visible emissions, failure to maintain equipment and failure to certify compliance with the plant’s Title V operating permit.” Via open records requests, GASP determined that 2015 and 2017 site inspections showed several blast furnace equipment deficiencies. You can view six examples here. As for EPA’s role, ACHD explained: “To enhance the Health Department’s enforcement efforts, ACHD has actively engaged the EPA over the course of the last nine months. The EPA brings an expanded level of federal expertise, as well as additional enforcement capacity that will support stronger action by utilizing the Department of Justice and EPA’s capacity to enact more stringent penalties.” What happened next? A bunch of silence from regulators - for YEARS - even as U.S. Steel continued to buck air quality rules and violate the terms of Edgar Thomson’s operating permit. Now, let’s fast forward to 2020 - when GASP began demanding an update from regulators about the status of that 2017 enforcement order and what exactly they were doing to force U.S. Steel to FINALLY bring Edgar Thomson into compliance with air quality rules following myriad pollution episodes at the facility. For example: U.S. Steel on March 26, 2020, made a report to the U.S. Coast Guard National Response Center (NRC) at 9:11 p.m. concerning a release into the open air of approximately 100 pounds of anhydrous ammonia. CREATE Lab/Breathe Project - BreatheCam.org Then, on June 17, 2020, GASP flagged a dark brown plume emanating from the Edgar Thomson Works and demanded information from the company and ACHD. On June 25, 2020, ACHD announced a sulfur dioxide (SO2) exceedance at the North Braddock air monitoring station that occurred that day. It also announced the brown plume emanating from the Edgar Thomson Works June 17 was the fault of a valve failure at the plant. In early August, GASP announced the launch of a petition demanding EPA and ACHD to provide a formal update - noting four years of radio silence from the regulators. Despite those pleas, regulators stayed mum, all while Edgar Thomson’s history of fouling the Mon Valley’s air continued. In January of 2021, ACHD issued an enforcement order against U.S. Steel for a failed stack test at Edgar Thomson and assessed an $8,000 civil penalty. Remember that report U.S. Steel made regarding that release of 100 pounds of anhydrous ammonia? ACHD issued an enforcement order against U.S. Steel for failing to report that breakdown in a timely manner as required by its Title V operating permit in February 2021. A $4,165 civil penalty was assessed. Then in August 2021, there was another high-profile air pollution incident at the facility. In an interview with WESA, then-Executive Director Rachel Filippini said: “This lack of transparency… is very frustrating for people that have to live with the brunt of this pollution day in and day out. People deserve to have answers, they deserve to know what caused it and how it will be addressed. And ultimately, how can they know that it’s not going to happen again?” GASP’s and others’ calls for transparency continued through 2021 and 2022 via public comments to the board of health, conversations with ACHD, social media posts, and rallies. Then came the big news May 17, 2022: A deal had been reached. U.S. Steel had agreed to pay a $1.5 million penalty and make extensive improvements at its Edgar Thomson facility in Braddock Borough as part of a consent decree announced with EPA and ACHD to settle those longstanding air pollution violations. Here’s what a release issued by the EPA said: "Everyone has the right to clean air, and the Allegheny County Health Department continues to work to ensure that right for all residents,” said ACHD Director Dr. Debra Bogen, Director of the Allegheny County Health Department. “This settlement is another step toward that goal in Braddock and surrounding communities, many of which are designated environmental justice communities. We are pleased that a large portion of the Health Department’s share of the civil penalty will directly benefit Braddock and other Mon Valley communities that experience a disproportionate share of the environmental impact of the pollution this consent decree concerns." The settlement mandated U.S. Steel make numerous improvements in training, monitoring and work practices to increase compliance and timely response to air pollution. Additionally, the company was tasked with conducting studies on potential improvements to its pollution control systems. The settlement also includes a supplemental environmental project solely credited against ACHD’s share of the penalty in which U.S. Steel would provide funding to the Allegheny County Department of Economic Development for a specific environmental project. Specifically, U.S. Steel will provide $750,000 in funding to the Allegheny County Department of Economic Development in support of the creation of a multimodal connection trail for hikers and bicyclists that links the Great Allegheny Passage in Rankin Borough to the Westmoreland Heritage Trail in Trafford Borough through the Turtle Creek Valley. The project’s aim was to create another multimodal connection to communities near U.S. Steel Edgar Thomson Works, including Rankin, Braddock, North Braddock, East Pittsburgh, Turtle Creek, Wilmerding, Monroeville, Pitcairn, and Trafford, North Versailles, East McKeesport and Wall. The then-draft settlement was subject to a public comment period. Despite robust comments submitted by residents and nonprofits like GASP, the deal was finalized Dec. 16, 2022, with zero changes made, reflecting that ACHD and EPA declined to implement any input gleaned from that process. What exactly did the consent decree mandate? GASP will explore that and more in Chapter 2.

U.S. Steel has contested citations issued by the U.S. Occupational Safety and Health Administration (OSHA) stemming from the deadly August 2025 explosion at the Clairton Coke Works. The OSHA website shows the company has contested all 10 of the violations - nine of which were related to subpar safety procedures and employee training, and one was for failing to provide the agency with required reports as required. U.S. Steel was fined $118,000 for those violations. One of U.S. Steel’s contractors - MPW Industrial Services - was cited nine times in relation to the explosion and fined $68,000. The OSHA website shows MPW also contested those violations. We continue to follow this issue closely. For more information on the explosion, visit GASP’s resource page here. Editor’s Note: The OSHA website also shows OSHA again inspected the Clairton Coke Works on April 8 based on a complaint made to the agency. It is still listed as open. Here’s what we know:

We wanted to issue a HUGE SHOUT OUT to all the folks who joined us on our walk-and-talk with Allegheny Land Trust last week at Churchill Valley Greenway. It's spring in Pittsburgh - this time of year, you never know what you’re gonna get. Could be blue skies and sunshine, could be gray and drizzly. This time around, we got the latter. Extra special thanks to Sara Klingensmith at ALT for all her help co-leading the walk! Despite a little rain and overcast skies, yinz were all great sports! Until the next one!

Gov. Josh Shapiro this week announced that the Pennsylvania Department of Environmental Protection (DEP) was seeking final court approval of a consent decree that will allow two generating stations in the Commonwealth to reopen and operate through 2032.   The Keystone and Conemaugh Generating Stations are both coal-fired power plants having the same operator. Keystone is in Armstrong County and Conemaugh is in Indiana County. Both plants had been slated to close at the end of 2028, when compliance with stricter federal wastewater and coal ash disposal regulations that were promulgated in 2015 would have become mandatory. When it made the decision to close the plants in 2021, the plants’ operator determined it was too expensive to comply with those regulations. Increased demand for electricity brought on by data centers has changed the analysis that led to the decision to close the plants.   Also playing into the plants’ decision to reopen: a still-proposed U.S. Environmental Protection Agency (EPA) rule that would allow DEP - as the Clean Water Act permitting authority for the plants - to extend the deadline for the plants to comply with the 2015 federal wastewater and coal ash disposal regulations, provided that DEP finds an “unexpected” change in electricity prices or a surge in demand for electricity has occurred. Nothing in the Consent Decree purported to alter the plants’ obligations under the air pollution laws and regulations, so, presumably, the plants will operate pursuant to their existing Title V Operating Permits (which you can access here and here).  Although both plants’ Title V Operating Permits have expired, the plants may still operate under them because the plant operator submitted timely renewal applications (which DEP has not acted on). “Although the reopening of the plants might help ease the strain on the electric grid, it will be bad for air pollution in areas downwind from the plants,” said GASP Senior Attorney John Baillie. “For 2024, the Conemaugh plant reported 1,508 tons of sulfur dioxide emissions and 1,234 tons of oxides of nitrogen emissions, and the Keystone plant reported 7,322 tons of sulfur dioxide emissions and 1,112 tons of oxides of nitrogen emissions.”   More information regarding those emissions is available here.

Several months ago, we blogged about the U.S. Environmental Protection Agency’s proposal to redesignate Allegheny County from nonattainment of the 2012 National Ambient Air Quality Standard (NAAQS) for fine particulate matter to attainment. We have an update: In the April 16 edition of the Federal Register, EPA published a Final Rule that does, in fact, redesignate Allegheny County to attainment of the 2012 NAAQS for PM2.5. To put it another way: It’s official, official now. Two things to note:  Achieving attainment does not mean that sources of PM2.5 and regulators can take their feet off the gas, as the regulations that achieved attainment remain on the books as part of what’s known as the Maintenance Plan for Allegheny County.   However, any new major sources of PM2.5 in Allegheny County, or any new major modifications to existing major sources of PM2.5, will be subject to Prevention of Significant Deterioration requirements rather than stricter Nonattainment New Source Review requirements. Prevention of Significant Deterioration requirements are designed to ensure that a new source does not knock an area out of attainment of a NAAQS. April 16’s Final Rule caps a long process that resulted in the closure of several sources of PM2.5 and the installation of improved emission controls at many others – those are outlined in the November 20, 2025 Proposed Rule for the redesignation.   “EPA’s redesignation of Allegheny underlines how the Clean Air Act works, albeit slowly, to promote public health,” said GASP Senior Attorney John Baillie.

Standing shoulder-to-shoulder with local families and environmental advocates, the   Group Against Smog and Pollution (GASP)  on Monday attended a public hearing to challenge the installation permit for the EQT Leto Well Pad and Dehydrator in West Deer Township. GASP joined our partners at   Concerned Residents of West Deer (CROWD) , a dedicated group of neighbors who have spent years fighting to protect their community from heavy industrial shale gas operations in residential and densely populated areas. We also collaborated with the   Environmental Health Project (EHP)  and   Protect PT   to raise concerns regarding the Leto project’s potential air quality and public health impacts. This hearing marked the latest chapter in a long-standing battle for some concerned residents of West Deer Township. The Leto project has been a lightning rod for controversy since its inception. While West Deer supervisors initially approved the conditional use for the well pad in 2023, some residents have remained steadfast in their opposition. Local advocates argue that the site is fundamentally unsuitable for   hydraulic fracturing , commonly referred to as fracking because of its density and potential for noise, light, and—most critically—air pollution. Most recently, on Monday, April 13, the Allegheny County Health Department (ACHD) accepted public comment on the permit, which governs how air -pollution- control equipment will operate on-site. Those pieces of equipment are known sources of Volatile Organic Compounds (VOCs) and Hazardous Air Pollutants (HAPs), which can contribute to respiratory issues and other long-term health complications. CROWD said health impacts were a major concern. "EQT's Leto well site, where they plan to build the dehydrator that will spew approximately 70 tons of toxic pollutants yearly, is surrounded by old coal mining "patch" homes; the houses are built close to one another, with 855 people living in this small community. These pollutants are known to cause acute & chronic health issues, as well as contributing to cancer, especially in children and elderly, which make up 53% of this neighborhood," the group said in a statement. They added: "The cumulative effect of gas operations in this small area, including fracking wells, an approved compressor station, an interconnect, and nonstop diesel truck traffic, is very concerning.  Adding a TEG dehydrator to this industrial buildout in a residential area is unacceptable. With over $2 billion in profit, EQT can certainly afford better technology that is less polluting and will be more protective of the families and vulnerable populations living in this area." Environmental Health Project agreed. “Given the vast body of scientific research linking shale gas development to adverse health outcomes, combined with EQT's history of health and safety violations, we hope the Allegheny County Health Department exercises its authority to ensure adequate precautions are taken at this site,” Talor Musil of EHP said. "We see companies like EQT add polluting equipment to communities in a piecemeal fashion in order to hide the true pollution burden from the community and local government,” Gillian Graber of Protect PT said. “That is why it is imperative that the ACHD consider the full buildout of polluting infrastructure and employ the precautionary principle to protect the health of the community.” GASP was proud to stand with community members and support their grassroots work. “Public health should never be a secondary consideration to industrial expansion,” GASP Executive Director Patrick Campbell said. “We were there to help ensure the Allegheny County Health Department (ACHD) hears the community's demand for the most stringent protections possible under the law.” You can read   GASP’s full comments here.

The Allegheny County Health Department (ACHD) has issued a $7,140 civil penalty against NCP Carbon for repeated air quality violations and failure to report equipment breakdowns in 2025. Located in Jefferson Hills, the facility specializes in carbon products, including carbon raiser, injection carbon, and metallurgic coke. According to a March 9 ACHD enforcement order, between June and October 2025, department representatives documented several instances of excess emissions originating from the facility’s baghouse and thermal dryer.  While the emissions themselves are a concern, NCP Carbon is specifically being cited for failing to notify ACHD - on five separate occasions - about equipment breakdowns as its permit requires. In fact, the enforcement order indicates ACHD only received reports after contacting the operator themselves. NCP Carbon has been ordered to: Correct all violations immediately. Report all future breakdowns within the mandatory 60-minute window. Submit written notices   within seven days of any original notification. You can read the entire enforcement order here. Editor’s Note: The Allegheny County Health Department periodically updates its website to include documents related to air quality enforcement actions. As part of our watchdog work, GASP monitors this webpage and reports on the air quality violations posted there. However, the docket has not been updated since December 2025. GASP is filing Right to Know requests for enforcement documents each month. “Timely transparency is needed,” GASP Communications Manager Amanda Gillooly said. “It would be ideal if the county updated the Air Quality Program enforcement docket each month, so residents know what our local regulator is doing to protect the air we all breathe from bad actors. As it stands, the docket has not been updated yet this year.”

Remember that breakdown at U.S. Steel’s Clairton Coke Works this past January - the one that prompted the Allegheny County Health Department to issue this public statement? Because a GASP public records request has revealed new information: That the breakdown resulted in a demand for $10,000 in stipulated penalties against U.S. Steel. Why? Because of provision in a high-profile 2021 consent decre e  reached between the company, our friends at PennEnvironment, and the Allegheny County Health Department (ACHD). The caveat: That U.S. Steel would be fined $10,000 for the first consecutive calendar day for excess H2S grain loading where sulfur dioxide emissions at Clairton Coke Works exceed 20 tons. Fines increase if the violation runs more than one day. According to ACHD’s March 10 demand for stipulated penalties, the Clairton Coke Works emitted 22.6 tons of excess SO2 thanks to the Jan. 27 breakdown. You can read the entire demand letter here. For those who'd like to take a deeper dive into the incident, here are some other docs we received through the Right to Know process: The  initial breakdown report  U.S. Steel submitted to ACHD  The 24-hour written notice  U.S. Steel submitted to ACHD ACHD’s notification to U.S. Steel that there was an exceedance of the H2S 25-grain standard An email chain  between ACHD and U.S. Steel discussing flaring during the event Editor’s Note: The Allegheny County Health Department periodically updates its website to include documents related to air quality enforcement actions. As part of our watchdog work, GASP monitors this webpage and reports on the air quality violations posted there. However, the docket has not been updated since December 2025. GASP is filing Right to Know requests for enforcement documents each month. “Timely transparency is needed,” GASP Communications Manager Amanda Gillooly said. “It would be ideal if the county updated the Air Quality Program enforcement docket each month, so residents know what our local regulator is doing to protect the air we all breathe from bad actors. As it stands, the docket has not been updated yet this year.”

An enforcement action by the Allegheny County Health Department (ACHD) serves as a stark reminder that public health regulations aren't optional—even for state agencies. Here’s what happened: During a routine inspection in April 2025, ACHD representatives visited the I-376 Bridge over Boyce Road and determined that while the site already held a permit for sandblasting structural steel, crews were also performing unpermitted abrasive blasting on rusted rebar for concrete repairs. The penalty? According to March 9 ACHD enforcement order, PennDOT and Northeast Paving on were hit with a $4,030 fine.  Northeast Paving, the general contractor, admitted they had been blasting the rebar for days without providing prior notification to ACHD as required. It is unclear why it took nearly a year for the enforcement action to be issued. Under Allegheny County’s air pollution control laws - known collectively as Article 21 - any abrasive blasting project exceeding 1,000 square feet requires the ACHD to be notified at least 30 days in advance. In this case, the notification was submitted nearly a month after the work was already finished. Why do we care? Because abrasive blasting can release fine particulate matter and other pollutants into the air if not properly managed.  The 30-day notice period ensures ACHD can review the project to protect the air we breathe. You can read the entire enforcement order that GASP obtained through a Right to Know request here . You can read more about ACHD’s abrasive blasting regulations here. Editor’s Note: The Allegheny County Health Department periodically updates its website to include documents related to air quality enforcement actions. As part of our watchdog work, GASP monitors this webpage and reports on the air quality violations posted there. However, the docket has not been updated since December 2025. GASP is filing Right to Know requests for enforcement documents each month. “Timely transparency is needed,” GASP Communications Manager Amanda Gillooly said. “It would be ideal if the county updated the Air Quality Program enforcement docket each month so residents know what our local regulator is doing to protect the air we all breathe from bad actors. As it stands, the docket has not been updated yet this year.”