Public Source reported that a subcommittee of Allegheny County’s Air Pollution Control Advisory Committee is considering the draft of a rule that would require industrial polluters like US Steel to reduce emissions when a temperature inversion traps in pollution that exceeds EPA standards. The committee makes recommendations on air quality regulations to the Allegheny County Board of Health. During a December 8 meeting, the regulation subcommittee of the county’s Air Pollution Control Advisory Committee discussed a new draft regulation that air quality advocates hope could mitigate the impact of pollution on public health in the Mon Valley region, including the City of Clairton and McKeesport.
US Steel's Clairton Coke Works has been a central element in the debate over air quality in Allegheny County. In mid December, the state of Pennsylvania issued a warning to residents in the Mon Valley about the poor quality of its air during a temperature inversion. One day in November, air pollution in the Mon Valley reached 129 micrograms of fine particulate matter. The 24 hour standard set by the Pennsylvania Department of Environmental Protection is 35 micrograms per cubic centimetre. This level is considered especially unhealthy for sensitive groups like children, the elderly and people with asthma. The air also exceeded the state standard for hydrogen sulphide for seven days straight during a temperature inversion in early November.
US Steel has said it already is reducing emissions and that, during the most recent inversion, pollution was high in other parts of the county and state as well. US Steel external communications manager Ms Meghan Cox said “During the recent inversion, we were already operating at a reduced level. We made additional adjustments to our operations when the inversion began. Elevated emissions readings in other areas suggest region wide issues such as mobile sources and background levels from other areas are contributing to elevated levels during inversions."
Inversions, a weather phenomenon common during winter that traps cold air under a lid of warmer air, keeps pollutants from dispersing from sources such as cars, households and industrial facilities