The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Rhode Island. This revision addresses the infrastructure requirements of the Clean Air Act (CAA or Act) for the 2015 ozone National Ambient Air Quality Standards (NAAQS). This proposed action includes all elements of these infrastructure requirements except for portions of the ``Good Neighbor'' or ``transport'' provisions, which will be addressed in a future action.

The Environmental Protection Agency (EPA) is approving SIP revisions submitted by the States of Maine and New Hampshire as meeting the Clean Air Act (CAA) requirement that each State Implementation Plan (SIP) contain adequate provisions to prohibit emissions that will significantly contribute to nonattainment or interfere with maintenance of the 2015 ozone NAAQS in any other state. This action is being taken in accordance with the Clean Air Act.

The Environmental Protection Agency (EPA) is approving volatile organic compound (VOC) reasonably available control technology (RACT) State Implementation Plan (SIP) revisions for the Illinois portion of the Chicago-Naperville, IL-IN-WI nonattainment area (Illinois portion) under the 2008 8-hour ozone National Ambient Air Quality Standard (``NAAQS'' or ``standard'') submitted by the Illinois Environmental Protection Agency (``Illinois'' or ``Illinois EPA'') on January 10, 2019 and supplemented on April 30, 2020. EPA is also approving the Stepan Co.

The Environmental Protection Agency (EPA) is approving elements of a State Implementation Plan (SIP) submission from Ohio regarding the infrastructure requirements of section 110 of the Clean Air Act (CAA) for the 2015 Ozone National Ambient Air Quality Standards (NAAQS). The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. EPA proposed to approve this action on March 9, 2021, and received no adverse comments.