The U.S. Court of Appeals for the District of Columbia Circuit ruled on Jan. 4 that the U.S. Environmental Protection Agency (EPA) made an error when applying the provisions of the Final PM2.5 Implementation Rules under the general execution provisions, or subpart 1, rather than the particulate-matter-specific provisions, or subpart 4. The rules include the Final Clean Air Fine Particle Implementation Rule for Particulate Matter equal to or less than 2.5 micrometers and the Implementation of the New Source Review Program for Particulate Matter Less than 2.5 micrometers.
Environmental groups challenged EPA’s decision to promulgate the Final PM2.5 Implementation Rules pursuant to subpart 1 instead of subpart 4. EPA said the PM2.5 standard should be implemented under subpart 1 since subpart 4 was added by Congress specifically to address PM10 NAAQS. The court ruled for EPA to re-release the rules pursuant to Subpart 4 and not Subpart 1 because Subpart 1 is too “vague.”
EPA finalized an update to its PM2.5 NAAQS, shifting the standard from 15 micrograms per cubic meter to 12 micrograms per cubic meter in December. A court required EPA to issue a final standard by December 1, 2012 because it did not review the standards every five years as required under the Clean Air Act. The 15 micrograms per cubic meter standard was first implemented in 1997 in addition to PM2.5, which was added as a NAAQS pollutant the same year. EPA said it anticipates making initial attainment and non-attainment designations for counties by December 2014, with the designations likely to take effect in early 2015. States then have until 2020 to comply with the revised standard or request a five-year extension to 2025 based on the severity of a county’s PM2.5 problem and the availability of emission controls.
To read the entire ruling, click here.
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