Document rpV0V1EGgD6qXQ5DZ5LJERrBe

chlorine and mercury limits to ensure. as EPA contends, the limits can be met with existing controls. As described in Section I.B.4, EPA must reconsider whether surrogacy determinations or work practice standards are more appropriate for newly regulated IIAP than new numeric MACT floor emission limits for Main Stacks. Work practice standards and surrogate emission limits were raised by EPA in the Final Rule, which prevented SunCoke from commenting on this point during the public comment period. Further, due to the inadequate notice and comment period discussed in Section I.A above, it was impracticable for SunCoke to conduct a full analysis of EPA's data issues and provide that analysis to EPA within the comment period. These data issues result in MAGI. floor limits that do not approximate the limits "achieved" by the best-performing five sources, and therefore do not comply with the CAA using EPA's interpretation of the rule's requirements. EPA should reevaluate and revise these MAGI. floor limits, including addressing the issues described in this section. Establishing appropriate MAD' floor emission limits is of central relevance to the rulemaking. 6. New MAC l' floor emission HRSG Bipass/Wasie Heal Slacks from existing HARlircilities are based on insufficient and unrepresentative data and .fail to differentiate between Main Stacks and Bypass Vent Stacks. (40 (11.12. 63.7298). The MACT floor emission limits that EPA set for I IRSG Bypass/Waste I Teat Stacks from existing FINR facilities arc burdensome and, in the event that SunCoke is required to install environmental controls to meet those limits, would negate the purpose of Bypass Vent Stacks as passive safety devices. EPA established new MACT floor emission limits for AG, formaldehyde, 11g, PAI I, and PM from Bypass Stacks in the same manner as Main Stacks, using an incomplete data set that is not representative of FINR's operating conditions. A limited subset of available data and the application of the UPI. (to the limited data set) cannot account for variability and uncertainty with such limited data and does not consider the variability of chlorine and mercury in coal.`' And for Bypass Stacks, the variability of chlorine and mercury in coal has an even greater impact on emissions than it does for Main Stacks. Like Main Stacks, EPA offered no explanation for its exclusion of relevant data and the result was unreasonably low emission limits that are not representative of SunCoke emissions and cannot be met.66 The additional stack test data submitted to EPA on May 21, 2024, included ByPass Stack data that EPA had not previously considered. In applying the same methodology to Main Stacks and Bypass Vent Stacks, EPA ignored a very material difference between the two sources of emissions. In IINR coke ovens, Bypass Vent Stacks act as a passive failsafe safety device. In the event of loss of negative pressure in the common 89 Fcd Reg at 55711-55712: for discussion of variability of Hg in coal, see, e g., Mercury in U S. Coal--Abundance, I)istrihution, and Modes of Occurrence, U.S. Cieological Survey (Sept. 2001), https.1 'pubs usgs.gov'fs'fs09501/1s095-01.pdf See SunCoke comment letter, pp. 33-34 - 12 - Sierra Club FOIA 2025-EPA-04883 ED_018388_00000109-00072 SC_EVERSPLIT0005746