Ohio v. Environmental Protection Agency

Under the Clean Air Act’s “good neighbor” provision, aimed at addressing transboundary ozone pollution that can exacerbate health issues like asthma, bronchitis, and emphysema, the Environmental Protection Agency (EPA) in October 2015 set new air-quality standards for ozone pollution. This provision necessitates that “upwind” states mitigate emissions that could affect air quality in “downwind” states. Following this, states were required to submit plans indicating how they would meet these standards and reduce emissions impacting other states. However, the EPA rejected the plans from 21 states for proposing no changes and additionally addressed two states that had failed to submit plans. In response, it published a federal plan mandating power plants and other industrial facilities in these 23 states to implement existing controls more effectively from 2023 and adopt commonly used controls by 2026, along with requiring controls for other ozone pollution sources like cement kilns and industrial boilers. The plan also utilized an existing emissions trading program among the affected states.

This federal intervention sparked a legal challenge from three states, several companies, and trade associations, requesting a court to temporarily block the EPA rule. They labeled the federal rule a “disaster” that could lead to electric-grid emergencies, an assertion countered by the EPA and its supporters, who deemed such claims speculative. These supporters argued that delaying the rule’s enforcement would critically impede efforts in environmental protection and public health. Consequently, a dozen states initiated a lawsuit against the EPA’s rejection of their emission plans, highlighting the ongoing dispute over federal and state responsibilities in air quality management under the Clean Air Act’s provisions.