Redesignation of Portions of Westmoreland and Cambria Counties, Pennsylvania for the 2010 Sulfur Dioxide (SO2) National Ambient Air Quality Standards (NAAQS)

The Environmental Protection Agency (the EPA or the Agency) is finalizing the redesignation of portions of Cambria County and Westmoreland County, Pennsylvania, to "nonattainment" for the 2010 1- hour primary sulfur dioxide (SO<INF>2</INF>) national ambient air quality standard (NAAQS or standard). Westmoreland County was previously designated "attainment/ unclassifiable," and Cambria County was designated "unclassifiable." The EPA notified the Commonwealth of Pennsylvania of its intended redesignation of portions of Cambria and Westmoreland counties on February 17, 2023, and published a Notice of Availability (NOA) for this action on February 12, 2024. The EPA's redesignation of portions of these counties is based on modeled violations of the 2010 1-hour primary SO<INF>2</INF> NAAQS.