Document 3NOnm8xoobrdEZX7dVd7YkkeD

Hon. Lee M. Zeldin March 31, 2025 Page 6 Finally, it is significant to note that even if AC1 is later shown to be a technically feasible option, U. S. Steel estimates that the capital cost of such a system for Kcctac and Minntac could exceed $150 million, and that annual operating and maintenance costs will exceed S37 million. 'Ile -I-aconite R-I Rulc includes several new requirements and MAD' standards. However, the technology to control mercury is not available because no such technology has been demonstrated to control and meet the Taconite RTR Rule mercury limits for the taconite iron ore processing industry, either in the US or internationally. A Presidential Exemption is warranted for several reasons: No technologies employed at any taconite iron ore processing facility have demonstrated the ability to meet the Taconite RTR Rule's new MACT standards for mercury. No taconite iron ore processing facility has installed such controls for the new HAPs; nor are the facilities subject to any existing limits for the new HAPs. EPA's approach to completing the RTR and purported "gap tilling" pursuant to the LEAN decision are contrary to a plain reading of the Clean Air Act and are due no deference. Contrary to the Clean Air Act, the -I-aconite R I R Rulc imposes requirements that no source, domestically or globally, is known to acluallt achieve. 'Ile new mercury limits and requirements were erroneously determined, as more fully explained in U. S. Steel's comments to the proposed -I-aconite RTR Rulc and in our petition for reconsideration. EPA ignored data provided by U. S. Steel and other commenters that supports a finding that the new mercury limits were erroneously determined. C. S. Steel advised EPA that the mercury concentrations in taconite ore deposits vary widely both within each mine and between mines, which in turn affects mercury emissions. The primary source of mercury emissions from indurating furnaces is from the mercury contained in the greenballs (i.e., unfired taconite iron ore pellets). C. S. Steel and other commenters provided EPA with mercury concentration data for greenballs from each taconite iron ore processing facility and recommended that the EPA revise the proposed mercury limits for new and existing furnaces to address the variability inherent in the mercury concentration of greenballs. For this reason, C. S. Steel and other commenters suggested the EPA use the data to develop a raw material variability factor that could be used when calculating the MACT floor limits for mercury as EPA has done for other categories (e.g., see Brick MACE) instead of giving this information any consideration, EPA, in response, summarily dismissed the comment and suggested that the data were either insufficient or possibly invalid. Contrary to EPA's assertion, as U. S. Steel demonstrated in our petition for reconsideration and request for administrative stay, the data in the record is statistically sufficient to calculate a raw material variability factor. In fact, the data provided is equal to or of better quality than the data used to justify using a raw material variability factor in other rules. Sierra Club FOIA 2025-EPA-04883 ED_018388_00000151-00006 SC_EVERSPLIT0005886