Section 111(d) of the Clean Air Act ("CAA"), 42
U.S.C. § 7411(d), governs air emissions from stationary sources of air pollutants. Section 111(d) explicitly
requires the U.S. Environmental Protection Agency
("EPA") to develop guidelines for the States to create
their own Section 111(d) plans to establish "standards
of performance" for controlling air emissions from any
individual "existing source." Section 111(d)(1) further
provides that EPA guidelines "shall permit" States, in
developing their plans, to "take into consideration,
among other factors, the remaining useful life of the
existing source to which such standard applies."
The question presented is: Can EPA promulgate
regulations for existing stationary sources that require States to apply binding nationwide "performance
standards" at a generation-sector-wide level, instead of
at the individual source level, and can those regulations deprive States of all implementation and decision
making power in creating their Section 111(d) plans?

Can EPA promulgate regulations for existing stationary sources that require States to apply binding nationwide 'performance standards' at a level, instead of at the individual source level, and can those regulations deprive States of all implementation and decision making power in creating their Section 111(d) plans?