Medical Advocates for Healthy Air v. U.S. Environmental Protection Agency

MEMORANDUM

This case arises out of the Environmental Protection Agency’s (“EPA”) 1997 decision to change the measurement standard for setting the national ambient air quality standard (“NAAQS”) for the pollutant ozone. Prior to 1997, the EPA measured average pollutant concentrations hourly. In 1997, however, the EPA concluded that measuring average pollutant concentrations over an 8-hour span would better protect public health. The EPA also made the standard slightly more stringent, thus changing not only “the measuring stick [but also] the target.” South Coast Air Quality Mgmt. Dist. v. EPA (“South Coast ”), 472 F.3d 882 , 892 (D.C.Cir.2006).

Section 172(e) of the Clean Air Act (“CAA”) provides that when a NAAQS is “relaxed,” the EPA is authorized to approve controls that are “not less stringent” than controls previously in effect. The CAA does not address a change to the NAAQS that results in a strengthened standard.

This petition for review is a challenge by numerous environmental groups to the EPA’s approval of a revision to California’s State Implementation Plan (“SIP”) that authorized the San Joaquin Valley Unified Air Pollution Control District (“Pollution Control…