Earlier this month, the Ninth Circuit affirmed the dismissal of environmental groups’ Clean Air Act (CAA) citizen-suit actions against US EPA.  The court held that US EPA does not have a nondiscretionary duty to promulgate revised Prevention of Significant Deterioration (PSD) regulations when it revises a National Ambient Air Quality Standard (NAAQS).

The Plaintiffs – WildEarth Guardians, Midwest Environmental Defense Center, and Sierra Club – filed suit under the CAA’s citizen suit provision, seeking to compel US EPA to issue revised PSD regulations for ozone.  The provision authorizes suits against US EPA only for actions alleging the agency failed to perform a nondiscretionary duty.  The Plaintiffs asserted that because US EPA amended the NAAQS for ozone in March 2008, it had a nondiscretionary duty under CAA Section 166(a) to promulgate revised PSD regulations for ozone no later than March 2010.  However, the district court disagreed holding that the statute permits, but does not require, US EPA to issue such regulations and dismissed the Plaintiffs’ claim for lack of subject matter jurisdiction.  Plaintiff’s appealed this decision to the Ninth Circuit.

Plaintiff’s theory is premised on Section 166(a) of the CAA which requires US EPA to issue regulations implementing the PSD program.  For ozone and certain other pollutants, the agency must “conduct a study and not later than two years after August 7, 1977, promulgate regulations to prevent the significant deterioration of air quality which would result from the emissions of such pollutants.”  The statute immediately then provides:  “In the case of pollutants for which NAAQS are promulgated after August 7, 1977, the Administrator shall promulgate such regulations not more than two years after the date of promulgation of such standards.”

US EPA argued that the first and second sentences apply to two mutually exclusive sets of pollutants:  (1) those for which NAAQS were already promulgated as of August 7, 1977, and (2) those for which NAAQS would not be promulgated until sometime later.  Thus, US EPA interpreted Section 166(a) as mandating it to promulgate PSD regulations within two years after NAAQS are first issued only for a newly regulated pollutant. The Plaintiffs, on the other hand, contended that the second sentence covered all pollutants, including those for which NAAQS already existed.

The Ninth Circuit found that, while both parties’ readings were reasonable, it did not have to choose the “correct” interpretation because Section 166(a) was ambiguous about whether US EPA’s duty was mandatory in the first place.  The Court reasoned that when a plaintiff sues US EPA under the citizen-suit provision for failure to perform a duty, the nondiscretionary nature of the duty must be clear-cut or readily ascertainable from the statute giving rise to the duty.  Thus, the Ninth Circuit affirmed dismissal of Plaintiffs’ claims for lack of jurisdiction.

Interestingly, the Panel’s decision coincides with US EPA’s recent proposal for stricter NAAQS for ground-level ozone, which is discussed in more detail in our prior blog entry.  US EPA has proposed dropping acceptable levels of both primary and secondary ozone standards from the current 75 parts per billion (ppb) to a level in the range of 65 to 70 ppb.  Although US EPA did not include a standard of 60 ppb in the proposed range, it is taking comments on levels as low as 60 ppb.