The EPA is promulgating this interim final rule to clarify the scope of the monitoring required in operating permits issued by State and local permitting authorities or by EPA under title V of the Clean Air Act (Act). Specifically, this interim final rule clarifies that under the sufficiency monitoring rules, all title V permits must contain monitoring sufficient to assure compliance as required under sections 504(a), 504(b), 504(c), and 114(a)(3) of the Act, in cases where the periodic monitoring rules are not applicable. The EPA believes this interim final rule is necessary to address claims of confusion on the part of some source owners and operators, permitting authorities and citizens as to the scope of EPA's title V monitoring regulations while EPA conducts a notice-and-comment rulemaking to consider adopting as a final rule the same changes made by this interim final rule.