Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is disapproving a State Implementation Plan (SIP) revision submitted by the State of Louisiana, through the Louisiana Department of Environmental Quality (LDEQ), on November 20, 2016, and supplemented on June 9, 2017. The submittals were in response to the EPA's national SIP call on June 12, 2015, concerning excess emissions during periods of Startup, Shutdown, and Malfunction (SSM).

The Environmental Protection Agency (EPA) is approving into the Ohio State Implementation Plan (SIP) a source-specific volatile organic compound (VOC) limit, excluding water and exempt solvents, for the applicable process lines at Forest City Technologies, Plant 4, in Wellington, Ohio as contained in the June 23, 2020, operating permit issued by the Ohio Environmental Protection Agency. On August 14, 2023, EPA proposed to approve this action and received no adverse comments.

The Environmental Protection Agency (EPA) is approving portions and disapproving portions of a state implementation plan (SIP) revision submitted by the State of Colorado to meet Clean Air Act (CAA) requirements for the 2008 8-hour ozone national ambient air quality standards (NAAQS) in the Denver Metro/North Front Range nonattainment area (DMNFR Area). Specifically, the EPA is approving the submitted enhanced monitoring SIP element as meeting applicable Serious area requirements for the 2008 8-hour ozone NAAQS, and is disapproving the contingency measure element of the SIP submittal.

The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the State of North Carolina through the North Carolina Division of Air Quality (NCDAQ) via a letter dated April 13, 2021. The SIP revision seeks to modify the State's emission control standards by amending several air quality rules and removing a redundant rule for electric utility boilers. EPA is approving these changes pursuant to the Clean Air Act (CAA or Act).