The Environmental Protection Agency (EPA) is converting its September 22, 2017 conditional approval of revisions to the Texas State Implementation Plan (SIP), addressing Oxides of Nitrogen (NO<INF>X</INF>) Reasonably Available Control Technology (RACT) for the TXI Operations, LP (Texas Industries, Inc., TXI) cement manufacturing plant in Ellis County, to full approval. We are approving an August 21, 2018 SIP submittal which satisfies Texas' commitment which was the basis for our conditional approval. We are taking this action in accordance with the Clean Air Act (CAA, the Act).