EPA Proposes More Stringent PM 2.5 NAAQS

On June 29, 2012, the EPA proposed a new, more stringent national ambient air quality standard (NAAQS) for fine particulate matter (PM 2.5). The proposed revision would reduce the current annual PM 2.5 standard from 15 micrograms per cubic meter (µg/m3) to a range of 12-13 µg/m3.

In February 2012, various environmental groups and several states filed suit against EPA to enforce its non-discretionary duty under the Clean Air Act (CAA) to complete a review of PM NAAQS every five years. 42 U.S.C. §7409(d)(1). The U.S. District Court for the District of Columbia ordered EPA to propose new PM 2.5 standards because the agency had violated its five-year deadline. Pursuant to this court order, EPA entered into a consent decree with the plaintiffs under which the agency agreed to issue proposed revisions by June 14, and to finalize a new PM 2.5 NAAQS by December 14.

In addition to strengthening the PM 2.5 NAAQS, the EPA is also proposing a new, separate PM 2.5 standard to measure haze of 28 or 30 deciviews. A deciview is a measure of visibility. The EPA has also proposed to retain its existing 24-hour PM 2.5 standard addressing short-term exposures (35 µg/m3) and the existing 24-hour standard for PM10 (150 µg/m3).

Industry groups argued against setting a more stringent PM 2.5 standard, citing adverse economic impacts. However, EPA countered that the health benefits far outweigh the costs of compliance. Further, an EPA press release regarding the new proposed standard states “[t]hanks to recent Clean Air Act rules that have and will dramatically cut pollution, 99 percent of U.S. counties are projected to meet the proposed [PM 2.5] standards without undertaking any further actions to reduce emissions.” The statement is referencing anticipated air pollution reductions as a result of the Cross-State Air Pollution Rule (CSAPR), which is currently stayed pending a decision from the U.S. Court of Appeals for the D.C. Circuit.

Comment on the proposed PM 2.5 rule must be received by August 31, 2012. EPA will hold two public hearings regarding the new standard: one in Philadelphia, PA on July 17, 2012, and one in Sacramento, CA on July 19, 2012. EPA plans to issue the final standards by December 14, 2012. We will continue to provide updates as additional information becomes available.