Fearing climate change and worse air, Allegheny County to propose new pollution regulations

A temperature inversion that trapped pollutants close to the ground late last month was only the fourth such weather phenomenon in more than a decade.

But after air quality in the Mon Valley exceeded federal standards for particulate matter for six consecutive days last week because of the inversion, heavy fog and light wind, the Allegheny County Health Department is planning new regulations, beefing up its weather forecasting tools and working with Harrisburg on air quality legislation.

“Prior to December’s inversions, the county was on track for the second year in a row — and in our history — to be in compliance with air quality standards,” Ronald Sugar, interim director of the health department, said in a statement Thursday. “That accomplishment is now at risk.”

From 2008 to 2018, Allegheny County experienced four similar weather-related events that affected air quality. The health department said temperature inversions like the one last week could become more frequent because of climate change.

“ACHD recognizes that the increasing frequency of these temperature inversions is associated with climate change,” Sugar said. “We also recognize that industry isn’t the only contributor to poor air quality, as things like vehicle exhaust have a significant impact upon pollution.”

But Shannon Hefferan, a meteorologist at the National Weather Service in Pittsburgh, said climate change will not necessarily lead to more frequent temperature inversions, just the general warming of the atmosphere. Hefferan said a temperature inversion will only occur under certain circumstances, when warm air traps cold air near the Earth’s surface.

“You need a specific set-up with the weather to have that,” Hefferan said. “And that prolonged setup could cause some issues.”

The health department has increased staff, tools and procedures dedicated to monitoring air quality in recent years. Now, Sugar said the department plans to increase its advocacy for healthy air quality standards, implementing new regulations to correct short-term, weather-related pollution events.

The health department will propose new air quality regulations in 2020 to change the emission mitigation requirements for industry during weather-related pollution episodes. According to the health department, the goal is to have emission reduction plans in place that could be implemented within 24 hours notice from the health department.

During last week’s inversions, U.S. Steel reported no unusual activity at its plant in Clairton. The plant was on pace to set a record for fewest stack exceedences in December, the company said in a statement.

“These extended exceedences and higher pollution levels are a clear threat to the health of the county’s residents, but ACHD’s current regulations do not provide options to address this issue,” Sugar said.

The health department plans to enhance its weather forecasting abilities and include more public notifications.

The health department said it will work with elected officials to produce more air quality legislation, including a Senate bill that would increase fines for facilities that exceed pollution thresholds.