Document OEzngoRvkor33J1kem6BJoZ7K

r TALEN ell MONTANA ar $49.7M (I3&M's estimates using EPA's cost approach), and with a limited lifespan and limited generation to recoup the costs, it is far more likely that Colstrip would suffer a premature retirement with the potential for serious economic disruption and impacts on grid reliability and transmission. C. Should EPA Finalize the Proposed 0.010 lb/NIMBtu fPN1 Limit, EPA Should Create Additional Subcategories. EPA should not finalize the 0.010 lb/MMBtu fPM limit. But should EPA do so, the Agency should establish subcategories so that it accounts for Colstrip's unique design and circumstances. Specifically, EPA should establish a subcategory for coal-fired units that use wet scrubbers to address both SO, and PM, and that do not have ESPs ar 1-Ts, where the f-PM limit for those units is no lower than 0.025 lb/MMBtu pursuant to its authority under 42 U.S.C. 7412(c)(5). As discussed above, application of the 0.010 lb/MMBtu fPM standard to Colstrip is not appropriate or warranted. At most, EPA should require Colstrip to optimize its existing control technology, consistent with the burden borne by other ECUs, as evaluated by the Agency. While Ialcn Montana believes that its efforts to reduce fPM have already been optimized, a limit of 0.025 lb/MMBtu fPM may be more achievable, especially as compared to the 0.010 lb/MMBtu fPM limit, as it would at least provide Colstrip an opportunity to try to meet the limit without new control technology. It also would provide for a more stringent limit for Colstrip, with additional emission reductions, and would be more appropriate for Colstrip given its unique circumstances. As an additional alternative, EPA should establish a subcategory with units making an enforceable commitment to retire, where the f-PM limit remains at 0.03 lb/MMBtu through retirement.('' This would be in line with how EPA is providing lead time for older sources in other nilemakings." Creating a subcategory in the MATS rule for units committing to retire would greatly assist companies with moving forward on retirement plans without running the risk of being forced to retire early, which could create reliability concerns or, in the alternative, deliberating whether to install controls and continue operation longer than planned to recoup investments in the controls. I Jere, EPA should create a retirement subcategory allowing units to continue to meet the existing 0.03 lb/MMBtu f-PM standard so long as they opt-in to the retirement subcategory within 18 months after finalization of the rule. with a retirement date no later than December 31, 2035 (and where continued operation after 2035 would later be permitted if (i) the unit is essential to maintain regional grid reliability, as determined by the Western Regional Adequacy Program, Regional Transmission Organizations, Independent System Operators, North American Electric Reliability Corporation, or other similar system reliability authorities; or (ii) or if EPA determines A unit should qualify for the retirement subcategory as long as it commits to cease burning coal by the proposed deadline of December 31, 2035. " SI'I' c g., Proposed GI IG Rule, 88 Fed. Reg 33,240, 33,245 (May 23, 2023) (near-term retirement units); Federal "Good Neighbor Plan" for the 2015 O7one National Ambient Air Quality Standards, 88 Fed. Reg 36,654 (June 5, 2023). 21 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000307-00022 SC_EVERSPLIT0006118