Document N2w5OLp8qGvn5dGK8EdzvjaMV

USCA Case #24-1190 Document #2062093 Filed: 06/27/2024 Page 11 of 92 Colstrip to serve customers in Washington and Oregon, with those laws becoming effective in 2026 in Washington and 2030 in Oregon. b. Unlike the PNW Owners, Talen Montana and NorthWestern are not subject to these regulations promulgated by the applicable utility commissions in Oregon and Washington. 22. The Colstrip units are governed by a 1981 ownership agreement. Each Colstrip Owner's respective ownership interest in Colstrip is as follows: Chvner ..Av ista . NorthWestern Pact tiCorp PGE PSE Talen Montana Unit 3 I 5' a -100 0 20O lzqo a 300 G Unit 4 . I 0 300 n 1 0 0 - 20 o i5 n -- NorthWestern has agreed to acquire Avista's share as of January 1, 2026.5 23. Each of the regulated utility owners will evaluate compliance with the MATS Final Rule differently, largely because of their separate state's commissions and stakeholders and regulatory frameworks, i.e., laws in those states regarding use of electricity from coal fired power plants. Some owners, like North Western, must engage with their respective public utility commissions to determine what action would have the least impact on grid reliability and electricity costs to customers, See Declaration by John D. I lines ("NorthWestern Decl.") at J' 8, 37, 68. 10 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000309-00011 SC_EVERSPLIT0006174