Document oDz8E3Ogezaaa7xgpayDQrw

Hon. Lee M. Zeldin March 31, 2025 Page 8 astonishingly, excluded valid data as the process fell short of EPA's statutory obligation and precedent in setting MACT floors. Contrary to the plain language of the Clean Air Act and decades of precedent, EPA has turned the establishment and determination of MAC-IT Standards under the Clean Air Act Section 112 into a research and development statute. Because technology to meet the Taconite R-IR Rule mercury limits is currently unavailable, U. S. Steel and other sources will need to conduct research, including bench scale testing, to determine the potential technologies that could be used to meet the mercury limit. This research time could be extensive therefore the three-year time frame to meet the Taconite RJR Rule's mercury limits is insufficient. Congress envisioned a three-year time frame to install controls and meet new limits because it intended that the technology would be proven and known during the rule development. This is not the case for the Taconite MR Rule. C. S. Steel needs more time to better evaluate additional emission controls and to assess technical feasibility and to test, engineer, permit, fabricate, and install the new equipment and other controls before the date compliance is required. In addition, U. S. Steel needs more time to address unintended adverse environmental impacts from application of any technologies a task that is required by the Clean Air Act but was completely ignored by EPA. A two-year Presidential Exemption is necessary to account for these factors and to prevent irreparable harm to taconite iron ore processing facilities and the domestic steel industry; and is appropriate as EPA reconsiders the Taconite RTR Rule. B. Technology is unavailable to meet the new acid gas limits -- Hydrogen Chloride and Hydrogen Fluoride (See amendments to 40 (TR 63 Subpart RRRRR including hut not limiied to 40 (TR 63.9583(1), (1)(1)-(7); 40 (TR 63.9583(1), (1)(1)-(7); 63.9590(a), (h), (h)(1)-(h)(8); 63.9600(h), (h)(1)-(4) as applied to hydrogen chloride and hydrogen fluoride; 63.9610(d), (d)(1)-(d)(6) as applied to hydrogen chloride and hydrogen fluoride; 63.9620(1); 63.9621(a) as applied to hydrogen chloride and hydrogen fluoride; 63.9621(rd),(rd)(1)-(d)(9) as applied to hydrogen chloride and hydrogen fluoride; 63.9623(a)(8); 63.9623(j); 63.9630(a)-(e) as applied to hydrogen chloride and hydrogen fluoride; 63.9631 as applied to hydrogen chloride and hydrogen fluoride; 63.9634(i); 63.9634(k); 63.9634(1); 63.9637 as applied to hydrogen chloride and hydrogenfluoride; 63.9640 as applied to hydrogen chloride and hydrogenfluoride; 63.9641 as applied 10 hydrogen chloride and hydrogen fluoride; 63.9642 as applied to hydrogen chloride and hydrogen fluoride; 63.9650 as applied to hydrochloride and hydrogen fluoride; and ,S'uhpart RRRRR Tables 1 through 4 as applied to hydrogen chloride and hydrogenfluoride.) Without justification or reasonable explanation, EPA abandoned the decades old precedent that appropriately used particulate matter ("PM") as a surrogate for hydrogen chloride and hydrogen fluoride. Instead, EPA is inexplicably requiring the use of pH as an operating parameter for measuring acid gas removal efficiency. For acid gases, EPA recognized that it had been using PM as a surrogate for almost two decades, and that it had just recently "concluded there were no developments in practices, processes, and control technologies for indurating furnaces," 88 Fed. Reg. at 30,926, but proposed "to change the way we regulate hydrogen chloride and hydrogen fluoride emissions Sierra Club FOIA 2025-EPA-04883 ED_018388_00000151-00008 SC_EVERSPLIT0005888