On August 28, 2017, the Ninth Circuit Court of Appeals rejected State challenges to a 2014 Consent Decree requiring EPA to complete designations for national ambient air quality standard (NAAQS) attainment status for sulfur dioxide (SO2) for all remaining areas in the country. This is the latest in an ongoing battle in the courts that started with the promulgation of the most recent SO2 standard in 2010.
After issuance of the standard, each state was required to submit recommended designations for areas within their state. Based on these recommendations, EPA is required to designate areas as attainment, nonattainment, or unclassifiable.
In August of 2012, EPA was granted a one-year extension to make designations based on insufficient or questionable data available in some areas. As this extended deadline approached, EPA had designated only 29 areas leaving over 3,000 counties across the country with essentially no designation status. A resulting lawsuit sought to order EPA to issue the designations, but instead, a Consent Decree was issued, allowing designations to be phased in over a seven year period. The agreement requires three rounds of designations in 2016, 2017, and 2020. The latest lawsuit filed by Kentucky, North Dakota, Texas, Arizona, Nevada, and Louisiana sought to overturn the Decree based on the claim that the Decree imposed duties and obligations on the States without their consent, among other arguments. In its recent action, the Ninth Circuit affirmed the Decree. This leaves EPA under an existing order to continue to issue the next round of area designations by December 2017, followed by the remainder in 2020.