Not later than 12 months after November 15, 1990, the Administrator shall promulgate regulations or interpretive rulings to revise requirements under section
7411 of this title and parts C and D, as appropriate, to facilitate projects consistent in this subsection. With respect to parts C and D, such regulations or rulings shall apply to all areas in which EPA is the permitting authority. In those instances in which the State is the permitting authority under part C or D, any State may adopt and submit to the Administrator for approval revisions to its implementation plan to apply the regulations or rulings promulgated under this subsection.