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).