The D.C. Circuit added to federal air quality regulators’ winning streak on Friday, upholding a 2013 rule that revises air quality standards for fine particulate matter.
The rule lowers the National Ambient Air Quality Standard (NAAQS) for fine particulate matter from 15.0 µg/m3 to 12.0 µg/m3, and also tightens monitoring requirements for particulate air pollution. Writing for a unanimous court, Judge Kavanaugh cited the “great deference” given to EPA’s evaluation of “competing bodies of scientific research” in rejecting the National Association of Manufacturer’s challenge to the revised standard. The court also upheld revisions to the NAAQS that eliminate the use of “spatial averaging” of monitoring data to demonstrate compliance with the standard and require additional monitoring locations near heavily traveled roads in large metropolitan areas, as well as rejecting several procedural challenges to the sufficiency of EPA’s notice of the proposed rule and its response to industry comments.
The court’s decision is the latest in a string of cases in the D.C. Circuit (previously discussed here and here) and Supreme Court (discussed here) upholding EPA Clean Air Act rules. The common theme running through the majority decisions in each of these cases is the court’s willingness to defer to EPA’s technical expertise in setting air quality and emissions standard under the Clean Air Act. EPA has achieved these positive judicial outcomes notwithstanding criticism that EPA at times requests technical deference to mask imperfections in the rule making process and that EPA staff lacks adequate industry-specific experience to be entitled to such deference.
The biggest test of judicial deference to EPA expertise in the field of air quality regulation is still to come, when the Supreme Court issues its ruling on a challenge to EPA’s “tailoring rule” for the regulation of greenhouse gas emissions from power plants and large industrial facilities. As Morgan Gilhuly and I have previously discussed in our commentary on the Supreme Court’s EPA v. EME Homer City Generation decision, proponents of the federal regulation of greenhouse gases hope that that these recent decisions foreshadow the outcome of the tailoring rule case. A decision in that case, Utility Air Regulatory Group v. EPA, No. 12-1146, is anticipated before the end of the current term in June.
The challenge to the fine particulate NAAQS was brought in National Manufactures Association v. EPA, No. 13-1069. The court’s opinion is available here.