The Environmental Protection Agency (EPA) is taking direct final action to approve revisions to the State of Maryland's Clean Air Act (CAA) section 111(d)/129 State Plan for municipal waste combustors (MWCs). The revisions contain Maryland's amendments to Regulations .07 and .08 under the Code of Maryland Regulations (COMAR) 26.11.08. These amendments update the MWC references to opacity compliance. The Maryland Department of the Environment (MDE)'s discontinued Technical Memorandum (TM 90-01) is no longer applicable and the regulations now refer to COMAR 26.11.31, which codifies quality assurance (QA) and quality control (QC) procedures for continuous opacity monitors (COMs). EPA is approving this revision to remove TM 90-01 from Maryland's CAA section 111(d)/129 State Plan in accordance with the requirements of the CAA.