Air Plan Approval; District of Columbia; State Implementation Plan for the Interstate Transport Requirements for the 2008 Ozone Standard

The Environmental Protection Agency (EPA) is approving a state implementation plan (SIP) revision submitted by the District of Columbia (the District) that pertains to the good neighbor and interstate transport requirements of the Clean Air Act (CAA) for the 2008 ozone national ambient air quality standards (NAAQS). The CAA's good neighbor provision requires EPA and states to address the interstate transport of air pollution that affects the ability of other states to attain and maintain the NAAQS. Specifically, the good neighbor provision requires each state in its SIP to prohibit emissions that will significantly contribute to nonattainment, or interfere with maintenance, of a NAAQS in another state. The District submitted a SIP revision on June 13, 2014 that addresses the interstate transport requirements for the 2008 ozone NAAQS. On July 5, 2018, EPA published a proposed rule for just the good neighbor provision of the District's June 13, 2014 submittal. EPA is approving the District's SIP as having adequate provisions to meet the requirements of the good neighbor provision for the 2008 ozone NAAQS in accordance with section 110 of the CAA.