Local regulators are urging residents who live near US Steel’s Clairton Coke Works to limit their exposure to outdoor air because of ongoing pollution problems stemming from a Christmas Eve fire at the plant.
In a release, the Allegheny County Health Department said Mon Valley residents “particularly those with existing respiratory and/or cardiovascular conditions, children and the elderly” should limit their outdoor activities “until further notice.”
The agency said a December 24th fire at the plant damaged two gas dispatcher stations, resulting in releases of the pollutant sulfur dioxide (SO2) in excess of federal standards.
Sulfur dioxide is “a colorless gas with a strong odor similar to a just-struck match,” according to the release. “(S)ulfur dioxide can affect breathing and may aggravate existing respiratory and cardiovascular disease. Sensitive populations include those with asthma, individuals with bronchitis or emphysema, children, and the elderly.”
The agency says it’s talking with the company about how best to address the problems, and has ordered the plant to enact additional mitigation strategies. The company has adjusted its operations to limit air pollution, but the plant has exceeded federal air quality standards a total of six times since the fire, said Jim Kelly, the county health department’s deputy director for environmental health.
Kelly said the plant’s adjustments “appeared to be working” for a time, but the county issued the warning after there were two more exceedances of federal air standards early Tuesday.
“Now that we’ve had six, we thought it was really important to let the public know that this is a concern,” said Kelly, at an Allegheny County Board of Health hearing. “Those people with impaired respiratory systems — especially asthma –they can be a concern,”
Meghan Cox, a spokeswoman for US Steel, said in an email that the December 24th fire broke out at 4:15 a.m. in a control room at the plant. The fire was extinguished and contained, and there were no injuries. According to Cox, the fire damaged equipment used to reduce SO2 emissions and the company is working to repair those systems.
The Clairton facility is the largest coke plant in North America. Coke is a key component of steelmaking. To make coke, the plant bakes coal at high temperatures for many hours. The process creates coke oven gas, which contains sulfur.
Kelly said the fire damaged equipment used to take sulfur out of the coke oven gas.
“Their ability to remove the sulfur has been halted,” Kelly said. “And so what that means is that there is an increased amount of sulfur in the coke oven gas that is remaining at the facility.“
In a Jan. 7 letter to the county, the company said it was trying to limit emissions by mixing cleaner natural gas into the fuel stream on units it heats with coke oven gas, and flaring “as much coke oven gas as possible.” In addition, it is increasing coking times–the amount of time it bakes coke–which reduces the amount of pollution created in the process. The company said the building where the fire broke out was still being evaluated for structural safety.
The company is currently appealing a June enforcement order from the county that would force the plant to idle parts of the plant if it doesn’t clean up its air pollution, as air near the plant continues to fail federal air pollution standards. The county’s order carries a $1 million fine for chronic emissions problems dating to 2014.
The areas affected include the communities of Braddock, Clairton, Dravosburg, Duquesne, East
McKeesport, East Pittsburgh, Elizabeth Borough, Elizabeth Township, Forward, Glassport, Jefferson Hills, Liberty, Lincoln, McKeesport, North Braddock, North Versailles, Pleasant Hills, Port Vue, Versailles, Wall, West Elizabeth and West Mifflin.
This story has been updated.
CORRECTION: A previous version stated there have been a total of four exceedances of air quality standards. There have been six.
This story is produced in partnership with StateImpact Pennsylvania, a collaboration among The Allegheny Front, WPSU, WITF and WHYY to cover the commonwealth's energy economy.