The Department of Environmental Protection is seeking public comment on its proposed recommendations to the EPA for the designation of areas not meeting the revised annual health-based National Ambient Air Quality Standards (NAAQS) for fine particulates (PM2.5).

Reducing concentrations of this pollutant is important because levels above the health-based standard are a serious human health threat and can cause or contribute to other negative environmental impacts.

The EPA established a revised NAAQS for PM2.5 in February 2024. The annual standard for PM2.5 was made more protective and changed from 12 micrograms per cubic meter of air (µg/m3) to 9 µg/m3. An area does not attain the annual standard if the annual concentration, averaged over 3 years, is more than 9 µg/m3. Following promulgation of new or revised air standards, states are given the opportunity to submit recommendations for attainment/nonattainment areas, supported by the most recent quality-assured and quality-controlled monitoring data.

The proposed designation recommendations are based primarily on air quality ambient monitoring (2021—2023), as well as emissions data, meteorology, geography/topography and jurisdictional boundaries. Based on this information, the Department is seeking comment on recommending that the EPA designate as ”nonattainment” areas in Greater Pittsburgh; Harrisburg-Carlisle-York; Lancaster County and Greater Philadelphia. The Department is also seeking comment on recommending that the EPA designate the areas monitoring below the standard as ”attainment” areas and the remaining areas in this Commonwealth as ”unclassifiable/attainment.”

DEP will be submitting recommendations by March 2025. The EPA is expected to make final designations in February 2026. The Department would then have 18 months to develop a plan for any areas designated as nonattainment to meet 2024 Primary PM2.5 NAAQS. This proposal is available on the Department’s web site at http://www.ahs.dep.pa.gov/eComment.

DEP will provide the opportunity to hold three public hearings, if requested, to receive comments on the proposals. The first hearing will be held from 1 p.m. to 3 p.m. on Jan. 21, in the Delaware River Room, in the Department’s Southeast Regional Office, 2 East Main Street, Norristown, PA. The second hearing will be held from 1 p.m. to 3 p.m. on January 21, 2025, in the Waterfront Room, in the Department’s Southwest Regional Office, 400 Waterfront Drive, Pittsburgh, PA. The third hearing will be held from 1 p.m. to 3 p.m. on January 23, 2025, in the Susquehanna Room, in the Department’s Southcentral Regional Office, 909 Elmerton Avenue, Harrisburg, PA.

Persons wishing to present testimony should contact Amanda Rodriguez at P.O. Box 8468, Harrisburg, PA 17105, (717) 787-7677 or amarodrigu@pa.gov no less than 24 hours in advance of the public hearing to reserve a time. Witnesses will be limited to 10 minutes and should provide two written copies of their comments.