Document 06wZVjeXp5Lm709nVLJ8Ko10d

USCA Case #24-1190 Document #2062093 Filed: 06/27/2024 Page 7 of 92 Colstrip's unique ownership structure. Talen Montana has already begun the process of expending funds to study the compliance options and timelines, and millions of dollars will be required to continue engineering and design efforts later this year, ramping up further next year as construction would need to begin. i. Per the above points, Talen Montana will directly experience material irreparable harm. These points are discussed in further detail in the remainder of this Declaration. TAIJEN MONTANA AND COLSTRIP OWNERSHIP 12. Talen Energy is an independent power producer that owns and operates approximately 10.7 gigawatts of power infrastructure in the United States. Talen Energy (through its subsidiaries) produces and sells electricity, capacity, and ancillary services into wholesale U.S. power markets, including PJM Interconnection, LLC ("PJM") and the Western Electricity Coordinating Council ("WECC"), with Talen Energy's generation fleet principally located in the MidAtlantic and Montana. Talen Energy's generation fleet includes wholly owned and partially owned assets that use nuclear, coal, oil, and natural gas as fuels. 13. Talen Montana is one of six owners, and is the operator, of Colstrip. Each of Colstrip's six owners have differing business models, which impacts their priorities and considerations for decidin; whether to install required costly controls under the MATS Final Rule and will complicate and lengthen the decision-making process. 6 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000309-00007 SC_EVERSPLIT0006170