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What You Need to Know About Allegheny County’s Proposed Coke Oven Regulation Revisions & How to

Updated: Sep 13, 2022

Editor’s Note: The public comment period for Allegheny County’s draft coke oven regulations closed as of 4 p.m. Jan. 21. THANK YOU to all who submitted comments!

If you are concerned about emissions from U.S. Steel’s Clairton Coke Works, there is no better time than now to let the Allegheny County Health Department (ACHD) know how you feel.

ACHD is now accepting public input on long-awaited revisions to its air quality regulations governing coke oven emissions. GASP will be submitting formal, legal comments, but we’re not writing just to let you know what *we* plan to do.

We want to help you understand some of issues so that *you* feel comfortable and confident providing your own comments to the health department.

Emissions from coke ovens have been an essential ingredient in our region’s poor air quality for over a century. Both ACHD and US Steel need to hear the public demand cleaner air. 

Here’s what you need to know to do just that:

First, Just a Bit of Housekeeping

Details of the proposed changes and supporting documentation are available online. The video on this webpage does provide a good overview of the changes.

Also, save the date: Comments must be submitted to ACHD by 4 p.m. on Jan. 21.

With that out of the way, let’s start at the beginning…

Coke Oven Emissions 101

Simply put, coke is produced by baking coal in an air-tight oven at very high temperatures for about 17 hours. Without oxygen, the coal doesn’t burn but essentially sweats out all of its impurities. Because of the high temperatures, those impurities evaporate and are collected as coke oven gas.

Coke oven gas is toxic, flammable, and carcinogenic because of ingredients like tar, benzene, ammonia, hydrogen cyanide, and hydrogen sulfide. This mixture is processed to remove some of the more acutely toxic constituents and the remainder is then burned to heat the coke ovens.

The problem from a public health standpoint is that this operation simply isn’t air-tight. Pipes leak. Oven doors leak. Emissions escape when loading and emptying the ovens. Equipment breaks down. And at every such point, the emissions could be extremely hazardous.

Because of a host of factors, not every molecule of air pollution emitted at the facility ends up affecting ambient air quality, but frequent odor complaints linked to hydrogen sulfide (H2S) near Clairton Coke provide strong evidence that some of those emissions are finding their way into local communities.

Hydrogen sulfide is a colorless, flammable gas with a distinct rotten-egg odor. Industrial sources of H2S include petroleum and natural gas extraction and refining, pulp and paper manufacturing, and waste disposal. 

The largest emitter of hydrogen sulfide in Allegheny County is U.S. Steel. According to Pennsylvania Department of Environmental Protection (DEP) Air Emissions reporting, Clairton Coke Works emitted about 156 tons of H2S in 2019—the most recent year for which data is available. For some perspective, all other sources of H2S in Pennsylvania combined only emitted 59 tons.

That level of emissions makes H2S both a potential indicator of less odorous but more dangerous pollutants in the air as well as a problem all unto itself. Pennsylvania has an ambient air quality standard for hydrogen sulfide, which is monitored by ACHD. Air quality exceeded that standard 28 times in 2020, according to preliminary data.

GASP has long called on ACHD to get a handle on those exceedances, last year petitioning the department to create stronger coke oven regulations – a move Air Quality Program officials said would help solve the problem. 

ACHD’s Coke Oven Regulations: What’s New & What They Will Do 

Presently, ACHD coke oven regulations spell out limits on emissions for aspects of the coking process where there is a potential for emissions such as when the ovens are loaded (called charging), when they are emptied (called pushing), and when the red-hot coal is cooled (called quenching). ACHD also has procedures for inspectors to follow to correctly determine compliance with those limits but they aren’t fully spelled out in the current regulations.

In revising its coke oven regulations, ACHD indicated it had four primary goals in mind:

  1. Incorporate inspection procedures for coke ovens;

  2. Address “issues of stringency” with federal and state requirements;

  3. Correct the coke oven gas standards; and

  4. Remove outdated language

GASP staff reviewed the proposed revisions at length. Our staff attorneys determined that modifications will essentially do three things:

  1. Retain existing limits on “fugitive emissions” from the coke ovens as well as concentrations of particulate matter in emissions from “combustion stacks.” FYI: Fugitive emissions include visible emissions from leaking doors, piping, etc., and the combustion stacks are essentially the chimneys for the ovens.

  2. Reduce limits on the sulfur content of coke oven gas burned at the facility in two steps – the first when the rule becomes effective and the second occurring on Jan. 1, 2025.

  3. Revise inspection protocols for fugitive emissions from the coke ovens.

Easier Said than Done

GASP supports ACHD’s efforts to reduce H2S and other coke oven emissions. In taking this step, we believe ACHD is acting to protect the health and safety of local residents and communities. Unfortunately, the revisions to the coke oven regulations fell short of our expectations.

We know that when regulators create new rules or retool existing regulations, they must keep many (sometimes contradictory and conflicting) factors in mind. For ACHD, one of those factors is language in the 2019 settlement agreement with U.S. Steel, which requires the department to be able to demonstrate that revisions made to coke oven regulations would reduce concentrations of both hydrogen sulfide and benzene at the Liberty air quality monitor.

The agreement also requires coke oven regulation changes to be “technically feasible.”

“What this means exactly in any given situation is anyone’s guess, but it’s safe to assume that an engineer or other industry expert has to be willing to testify that a required control or measure could be done, with a realistic cost-benefit ratio,” GASP senior attorney John Baillie explained. 

And guesswork isn’t something we should be engaging in at this point.

In the documentation accompanying the revisions, ACHD didn’t show its work. As a result, there’s no data establishing that the revisions will ultimately make the air in the Mon Valley any cleaner.

“ACHD has not attempted to demonstrate that the new rule conforms to the 2019 Settlement Agreement, specifically the requirement that any revisions result in reduced H2S levels,” Baillie said. “Rather, it justifies the rule based on a purported need to incorporate applicable federal and state standards into the county regs.”

But here’s the thing: GASP’s review shows that Allegheny County’s air pollution control regulations (known as Article XXI) already incorporate those rules by reference.

“This means facilities are already subject to such rules,” Baillie explained.

While there is no need to spell them out expressly in Article XXI, doing so may make it easier for industry, the public, and regulators to determine exactly which limits apply.

“To the extent ACHD wants to incorporate applicable state and federal rules, it should incorporate all such rules for the sake of clarity. The new rules would not do this,” he noted.


The new rules also do not incorporate:

  1. A federal limit on the total dissolved solid content of quench water (no more than 1,100 mg/L); or

  2. Federal limits on fugitive emissions that are based on rolling 30-day averages of observed emissions rather than instantaneous observations.

The “new” limits on fugitive emissions are, in fact, existing emission limits so any air quality improvements from them will thus depend on increased enforcement and compliance, he added. 

Fortunately, it’s not all bad news: The proposed limit on the sulfur content of coke oven gas is likely to help reduce the concentration of sulfur compounds – including both SO2 and H2S – in the ambient air at the Liberty monitor and in the vicinity of Clairton generally.  

Unfortunately, while this limit may be technically feasible for U.S. Steel to achieve, ACHD has not demonstrated that it is the case as required by the 2019 settlement agreement. 

“This leaves the regs vulnerable to a legal challenge brought by U.S. Steel,” Baillie said.  “ACHD should provide such a demonstration so that the regs hold up in court.”

How You Can Make Your Voice Heard on Allegheny County’s New Coke Oven Regulations

If you’ve read this far, you already know: Regulations are complex and the terminology and process can be confusing. GASP is fortunate to have two staff attorneys who review all this stuff and explain it to the rest of the team in a digestible way.

So we get it if you’re thinking to yourself, “I know this is important. I know that crappy air quality impacts my life – I smell the stank all the time – but I don’t think I know enough about it to really submit comments.”

Please know: You don’t need to be a lawyer or an expert to weigh in. Regulators, the regulated community, and watchdog groups like GASP might know the technical details and understand the underlying rules, limits, and regulations but we aren’t on the frontlines – YOU are.

It’s important for ACHD to hear this unified message from residents: 

We’re hopeful the revisions will help stem fugitive emissions from coke ovens and H2S exceedances but we are concerned there’s no guarantee the proposed changes will lead to cleaner air in the Mon Valley. ACHD must continue to do all it can to protect the health of residents impacted by decades of poor air quality. The public deserves to know that these updates will improve air quality.

It’s equally important for residents to share their personal experiences – your first-hand accounts give you your own expertise. We hope you use that expertise to help decision-makers understand how industrial air pollution impacts your day-to-day life. 

We hear the stories all too often: About children who needed to be taken to the ER after playing outside on a bad air day, about people shuttering their doors and windows on unseasonably warm days to keep pungent industrial odors at bay, about people who fear they will have to sell their beloved homes to protect their families from egregious emissions.

Those experiences are important for public officials *and* U.S. Steel to hear, and we hope you will consider sharing them by testifying at a public hearing slated for 5 p.m. Jan. 20, by sending in written comments by the Jan. 21 deadline, or both.

We want to make it as easy as possible for you to submit comments and encourage you to do so through our online form. Your comments will automatically be routed to ACHD.

More instructions on how to submit public comments can be found here.

Those who would prefer to present verbal testimony at the hearing must register through Zoom at least 24 hours in advance of the virtual hearing. Please note that testimony is limited to three minutes. 

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