Air quality still a concern in Mon Valley 3 weeks after Clairton Coke Works fire

No excess sulfur dioxide has been found in the air around the fire-damaged Clairton Coke Works for more than a week, officials said Wednesday, but they continued urging residents with respiratory issues to limit their time outside.

The Dec. 24 fire at the U.S. Steel-owned facility caused severe damage, but Allegheny County Health Director Dr. Karen Hacker said efforts to reduce harmful sulfur dioxide – or SO2 – emissions have been successful.

Hacker said the health department receives hourly updates on air-quality readings throughout the county, and the last reading that showed excess SO2 in the Mon Valley was recorded about 4 a.m. Jan. 8 in Liberty.

“Out of an abundance of caution, we want the public to know that there remains a potential risk for future exceedances,” Hacker said. “We are continuing to encourage Mon Valley residents to be aware of this risk, especially sensitive populations, those with asthma, individuals with bronchitis or emphysema, children and the elderly.”

U.S. Steel spokeswoman Meghan Cox said outside investigators continue working to determine the cause of the fire, but preliminary findings suggest the fire “was likely caused by a mechanical failure.”

Cox said there is significant structural damage.

“We are working around the clock to make the necessary repairs and to bring the facility back to normal operations,” she said. “We remain committed to employing measures only after it is determined that they are safe for our employees, contractors and the public.”

Health officials warned Jan. 9 that the fire had sent harmful gases into the air, which could affect residents in 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.

“We know that we need to do a better job of communicating information to impacted residents,” Hacker said in the statement. She noted that health officials have been in touch with community advocates, local government officials and environmental groups in the affected communities.

Until repairs are finished, she said, the health department will provide daily updates at 3 p.m. on the department website and Facebook page. Updates will also be issued through the county’s Allegheny Alerts system, for which one must create and account and choose how they would prefer to be notified.

Megan Guza is a Tribune-Review staff writer. You can contact Megan at 412-380-8519, mguza@tribweb.com or via Twitter @meganguzaTrib.