Environmentalists Challenge Gallia County SO₂ Designation

Environmentalists are challenging the EPA's designation of Gallia County and portions of Meigs County, Ohio, alleging the area is not in attainment for the 2010 sulfur dioxide National Ambient Air Quality Standards (NAAQS). Before the United States Court of Appeals for the District of Columbia Circuit, the Sierra Club contests EPA’s designation of the area as "unclassifiable." According to the Sierra Club, EPA made mistakes with technical analysis which rendered its designation unlawful and, thus, the area should be listed as being in nonattainment. EPA considers those areas that have air quality worse than the NAAQS as nonattainment. Nonattainment areas are required by EPA to, among other requirements, implement a plan to meet the standard or face penalties from the federal government.

In 2010, EPA revised the primary, or health-based, NAAQS for SO₂. EPA’s promulgation of the 2010 SO₂ NAAQS triggered the agency’s statutory obligation to “designate” all areas of the country according to whether they comply with the standard. Areas that comply are designated “attainment.” Areas that do not comply must be designated “nonattainment.” In some cases, EPA is not able to determine an area's status after evaluating the available information and designates an area "unclassifiable."

EPA had previously concluded that Ohio had inappropriately used a 38 percent bias adjustment in its calculation of background concentrations. However, EPA determined the information provided by Ohio did not clearly indicate whether the use of unadjusted background concentrations without the bias adjustment would have violated the standards and thus designated the region “unclassifiable.” The Sierra Club contends that, without the bias adjustment, the area would be in nonattainment.