US EPA has announced its intention to propose rules for the implementation of the 1 hour standard for sulfur dioxide. This rule is intended to provide state, local agencies, and tribes with the necessary information to comply with the 1-hour SO2 NAAQS. The rule will address the State Implementation Plan (SIP) requirements necessary for states to submit approvable maintenance SIPs as required under section 110(a)(1) of the Clean Air Act (CAA).
EPA anticipates the rule will address the requirements for adopting an emissions inventory, an attainment demonstration using refined air quality dispersion modeling, a contingency plan, control measures, as well as information on how states with areas designated as unclassifiable, which are required to submit maintenance SIPs under section 110(a)(1) of the CAA, can be redesignated to attainment.
Currently, EPA anticipates publishing a notification of proposed rulemaking (NPRM) in July 2012.