ELR Citation: 50 ELR 20121
No(s). 18-1285 (D.C. Cir. May 19, 2020)

The D.C. Circuit granted in part and denied in part Delaware's and Maryland's challenges to EPA's denial of their CAA §126(b) petitions requesting that the Agency impose additional limitations on certain upwind sources contributing to the states' nonattainment of ozone NAAQS. Maryland's petition argued that four coal-fired power plants that did not have catalytic controls should be required to operate their non-catalytic controls to curb releases of nitrogen dioxide. The court agreed, finding that the Agency couldn't claim that such controls were not cost-effective in light of the court's decision in Wisconsin v. Environmental Protection Agency. Delaware's petitions argued that three plants were not optimizing their existing controls, and requested a finding that the plants were violating the CAA's "good neighbor" provision with respect to both the 2008 and 2015 NAAQS. The court agreed with EPA that Delaware's own analysis showed the state was already meeting and maintaining the 2008 standard and would meet the 2015 standard by 2023 without requiring an additional upwind emissions limit, but acknowledged that the Agency impermissibly found that the state could not rely on out-of-state monitors to show a violation of ozone limits within its borders. It therefore granted and remanded to EPA the part of Maryland's petition to review that sought the use of non-catalytic controls on four power plants, but denied all other petitions.