This action will amend the Taconite Iron Ore Processing National Emission Standards for Hazardous Air Pollutants (NESHAP), 40 CFR part 63, subpart RRRRR, as required by the Clean Air Act (CAA). This action will address Louisiana Environmental Action Network v. EPA, 955 F.3d 1088 (D.C. Cir. 2020) (“LEAN”), in which the court held that EPA must set limits on uncontrolled hazardous air pollutant (HAP) emissions when the Agency conducts technology reviews under CAA section 112(d)(6), 42 U.S.C. section 7412(d)(6). The Taconite Iron Ore Processing NESHAP was promulgated pursuant to section 112(d) of the CAA on October 30, 2003. The residual risk and technology review (RTR) for this source category was promulgated pursuant to CAA sections 112(f) and 112(d)(6) on July 28, 2020. The NESHAP establishes emission limitations and/or work practice requirements based on maximum achievable control technology (MACT) for controlling emissions of HAP from new and existing major sources of HAP within the source category, including taconite ore crushing and handling operations, pellet indurating furnaces, finished pellet handling operations, and ore dryers. Pursuant to the D.C. District Court's April 15, 2021 order in Blue Ridge Environmental Defense League v. Regan, Case No: 1:16-cv-00364-CRC (D.D.C. filed Feb. 24, 2016), the EPA must complete the final action for the Taconite Iron Ore Processing NESHAP by December 18, 2023.