The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the State of Maine. This revision amends the definition of ``Ozone Transport Region'' in the State's Chapter 100 Definitions Regulation and revises language in the State's Chapter 113 Growth Offset Regulation regarding applicability of Nonattainment New Source Review in areas that, at a future date, may not be within the Ozone Transport Region. The intended effect of this action is to approve the submittal into the Maine SIP.

The Environmental Protection Agency (EPA) is approving the Clean Air Act State Plan revisions for Large Municipal Waste Combustors (MWCs) submitted by the Massachusetts Department of Environmental Protection (MassDEP) on December 18, 2018. The revised State Plan is in response to amended emission guidelines (EGs) for Large MWCs promulgated on May 10, 2006. MassDEP's State Plan is for implementing and enforcing provisions at least as protective as the EGs applicable to existing Large MWCs. This action is being taken under the Clean Air Act.

The Environmental Protection Agency (EPA) is finalizing approval of a State Implementation Plan (SIP) revision submitted by the State of South Carolina, through the South Carolina Department of Health and Environmental Control (SC DHEC or Department), on April 24, 2020. The SIP revision updates the definition of ``Spec. Oil (Specification Oil)'' and makes minor updates to formatting and numbering. EPA is finalizing approval of these changes pursuant to the Clean Air Act (CAA or Act) and implementing federal regulations.

Under the Clean Air Act (CAA), the Environmental Protection Agency (EPA) is granting requests by the California Air Resources Board (CARB or ``State'') to reclassify three nonattainment areas in California from ``Moderate'' to ``Serious'' for the 2015 ozone national ambient air quality standards (NAAQS). These three areas are herein referred to as the Eastern Kern, Sacramento Metro, and Western Nevada nonattainment areas.