Nine AGs Filed Amicus Brief Defending EPA’s Authority to Address Interstate Air Pollution

DECEMBER 18, 2023

New York Attorney General Letitia James led a coalition of nine attorneys general—along with Harris County, Texas and the City of New York—in filing an amicus brief in the Sixth Circuit defending the Environmental Protection Agency’s (EPA) authority to address interstate air pollution. Under the Clean Air Act’s Good Neighbor Provision, states are required to limit emissions that will interfere with neighboring states’ ability to meet air quality standards. Kentucky challenged EPA’s authority to administer this provision after the agency disapproved of Kentucky’s State Implementation Plan (SIP). In their amicus brief, the AGs defended EPA’s authority to substantively review and evaluate State Implementation Plans. The AGs argued that, contrary to Kentucky’s claims, EPA’s disapproval of Kentucky’s implementation plan was reasonable and well-founded. The AGs also argued that the case should be transferred to the D.C. Circuit under the Clean Air Act and to avoid piecemeal review.