This rule modifies the Agency's procedures for delegating hazardous air pollutant (HAP) standards and other requirements to State, local, and territorial agencies, and Indian tribes (S/L/T). Under section 112(l) of the Clean Air Act (Act), EPA is authorized to approve alternative S/L/T HAP standards or programs when such requirements are demonstrated to be no less stringent than EPA's rules. Today's changes to section 112(l) revise our procedures and criteria for approving alternative S/L/T measures. Today's action amends our existing regulations that implement section 112(l) of the Act. The changes will help S/L/T's by offering a range of options for demonstrating equivalence with the Federal requirements and expediting the approval process. These changes are in response to requests we received from State and local air pollution control agencies to reconsider our existing regulations in light of implementation difficulties that they anticipate or have experienced. We believe this effort is consistent with the President's regulatory "reinvention" initiative. It will result in less burden to S/L/Ts, regulated industries (by avoiding duplicative requirements), and the Federal Government, without sacrificing the emissions reduction and clean air enforcement goals. This rulemaking also addresses requirements that apply to S/L/Ts, should they choose to obtain delegation or program approval under section 112(l). (Note that obtaining delegation under section 112(l) is voluntary). This rulemaking does not include any requirements that apply directly to stationary sources of HAP or small businesses that emit HAP.