Dear Administrator Regan: The Environmental Protection Agency (EPA or Agency) has proposed a Revocation of the 2020 Reconsideration, and Affirmation of the Appropriate and Necessary Supplemental Finding for EPA’s Mercury and Air Toxics Standards. 87 Fed. Reg. 7,624 (Feb. 9, 2022). EPA’s 2016 Supplemental Finding followed the Supreme Court’s decision in Michigan v. EPA, which held that EPA must consider costs in evaluating whether it is appropriate and necessary to regulate EGUs. EPA is correct to restore the “appropriate and necessary” determination underpinning the Mercury and Air Toxics Standards (MATS) given the industry’s full implementation of MATS. Such a restoration provides critical regulatory and business certainty to the industry regarding regulation under Clean Air Act (CAA or Act) section 112.
Driven by several factors—including customer demands, declining costs for renewable energy, technology developments, and federal and state regulatory obligations—the electric power industry is in the midst of a transition of its electric generating fleet that will continue over the next decade and beyond. Concurrent with this transition, electric companies, public power utilities, and electric cooperatives are making significant investments to make the energy grid smarter, cleaner, more dynamic, more flexible, and more secure in order to integrate and deliver a balanced mix of central and distributed energy resources reliably and provide resilient electricity to customers.