Air Plan Approval; Colorado; Addressing Remanded Portions of the Previously Approved Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards

Publication Date: 
Friday, May 6, 2022 - 4:00am

On January 5, 2021, the United States Court of Appeals for the Tenth Circuit granted the Environmental Protection Agency's (EPA) motion for a voluntary remand without vacatur of two parts of EPA's 2020 final rule approving Colorado's infrastructure state implementation plan (SIP) submission for the 2015 8-hour ozone national ambient air quality standards (NAAQS) (2020 final rule). In this document, EPA proposes to address those two remanded parts of the 2020 final rule: EPA's conclusion that Colorado's infrastructure SIP submission met the State's good neighbor obligation under Clean Air Act (CAA) section 110(a)(2)(D)(i)(I); and EPA's conclusion that Colorado's infrastructure SIP submission provided ``necessary assurances'' of the State's authority to regulate agricultural sources under CAA section 110(a)(2)(E)(i). EPA is proposing to approve Colorado's infrastructure SIP submission pursuant to CAA section 110.

Environmental Protection Agency