The following table sets out on a state-by-state basis exactly which portions of each state's implementation plan have been approved or disapproved by the Administrator of the Environmental Protection Agency. The citations in entries down the left-hand side of the page are to sections of 40 C.F.R. Pt. 51, setting forth the requirements for a complete implementation plan. The numbers below each state's name are page references to the Federal Register at which the action noted occurred. In all cases, references are to Volume 37 of the Federal Register. This chart represents only materials published in the Federal Register and may not reflect informal agreements or court ordered changes that have not yet been promulgated. It includes all material published in the Federal Register through March 5, 1973. ELR readers should be aware that in the Federal Register of March 8, 1973, the Administrator added a new section of 40 C.F.R. Pt. 52, disapproving all state implementation plans on the grounds that they failed to include provisions to ensure procedures and regulations adequate to ensure that ambient air quality standards are maintained. See 38 Fed. Reg. 6279 and Advance Notice of Proposed Rule Making, 38 Fed. Reg. 6290.