USCA Case #24-1190 Co strip PM Evaluation -- Final Document #2062093 Apri 29, 2024 Filed: 06/27/2024 TABLE OF CONTENTS Page 29 of 92 TOC Page No. 1.0 EXECUTIVE SUMMARY 1-1 1.1 Capital Cost Analysis 1 -1 1.2 O&M Cost Analysis 1-3 2.0 INTRODUCTION 2-1 2.1 Colstrip Steam Electric Station 2-1 2.2 Cost Development 2-1 2.3 Limitations and qualifications 2-2 3.0 EMISSION REDUCTION TECHNOLOGY DESCRIPTION 3-1 3.1 Pulse-Jet Fabric Filter 3-1 3.1.1 Process Description 3-1 3.1.2 Pulse-Jet Fabric Filter Advantages 3-3 3.1.3 Pulse-Jet Fabric Filter Disadvantages 3-3 3.2 Dry Electrostatic Precipitator 3-4 3.2.1 Process Description 3-4 3.2.2 Electrostatic Precipitator Advantages 3-6 3.2.3 Electrostatic Precipitator Disadvantages 3-6 4.0 EMISSION GUARANTEES 4-1 5.0 COST EVALUATION 5-1 5.1 Capital Costs 5-1 5.1.1 General Estimate Basis 5-3 5.1.2 Discipline Information 5-3 5.2 Operation and Maintenance, Levelized Costs 5-7 5.2.1 O&M Cost Basis 5-7 6.0 SUMMARY 6-1 6.1 Summary 6-1 6.1.1 Balance of Plant Impact Analysis 6-1 APPENDIX A - DRAWINGS APPENDIX B - VENDOR QUOTES * ** * * Talen Montana TOC-1 Sierra Club FOIA 2025-EPA-04883 Bums & McDonnell ED_Ol 8388_00000309-00029 SC_EVERSPLIT0006192

USCA Case #24-1190 Co strip PM Evaluation -- Final Document #2062093 Apri 29, 2024 Filed: 06/27/2024 Page 39 of 92 Emission Reduction Technology Assessment Figure 3-3: Typical Dry Electrostatic Precipitator Process Flow Diagram Dirty Gas INLET Clean Gas OUTLET ESPs offer an advantage of operating at a very low pressure drop across the system.

USCA Case #24-1190 Document #2062093 Filed: 06/27/2024 Page 15 of 123 the electricity needed to serve customers.

Minnkota Power Cooperative, Inc.

THE MATS RTR CREATES GRID RELIABILITY CONCERNS DUE TO EARLY RETIREMENTS OF COAL-FIRED UNITS 59.

Message From: Sent: To: Subject: Noonan, Jenny [Noonan.Jenny@epa.gov] 3/21/2025 6:25:34 PM Dunkins, Robin [Dunkins.Robin@epa.gov]; Do, Bebhinn [do.bebhinn@epa.gov]; Cortelyou-Lee, Jan [CortelyouLee.Jan@epa.gov] RE: 2025.03.21_Presidential Exemption Directions_ Edits.docx Thanks Robin.

Message (Digitally Signed) From: Sent: To: CC: Subject: Attachments: Malcolm Langlois [mlanglois@anduril.com] 3/31/2025 5:36:37 PM AirAction [AirAction@epa.gov] Brian Cruz [bcruz@anduril.com]; Ann Marie Rosas [amr@anduril.com]; Suhas Gowda [sgowda@anduril.com ] Presidential Exemption: National Emission Standards for Hazardous Air Pollutants from Hazardous Waste Combustors: Anduril Industries, Inc. - Mississippi smime.p7s Environmental Protection Agency personnel.

March 28, 2025 Ionorable Lee Zeldin Office of the Administrator (1101A) United States Environmental Protection Agency 1200 Pennsylvania Avenue, N.W.

March 28, 2025 U.S.

From: Western Caucus Foundation rsvp@westemcaucusfoundation.org To: "leila gefto@ios.doi.gov" leila getto@ios.doi.gov Subject:[EXTERNAL] Tomorrow: VIRTUAL Western Caucus Foundation Monthly Staff Breakfast Date: Thu, 09 Jul 2020 20:14:14 +0000 This email has been received from outside of DOI - Use caution before clicking on links, opening attachments, or responding.

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Document 3 From : Se nt: To: Cc: Subject: Matthew Boyle Thu, 3 Apr 2025 13:29:11 +0000 Hebert, Ashley Dietderich, Ben; Lamanna, Isabelle; Woods, Andrea [EXTERNAL] Re: Breitbart event details -- Hey guys wanted to check in again here on locking in a date for May or June Sent from my iPbone On Mar 31, 2025, at 8:06 PM, Matthew Boyle <mboyle@breitbart.com> wrote: Ok great - I'm gonna be overseas next week so would be great if we can lock something in by the end of this week if possible Keep me posted Thanks for your guys help here - we are very much looking forward to this Sent from my iPhone On Mar 31, 2025 , at 7:36 PM, Hebert, Ashley <ashley.hebert@hq.doe.gov> wrote: Great!

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From: Sent: To: Subject: Tatulyan, Kevin Mon, 21 Jul 2025 19:14:20 +0000 Duckman, Ashley Accepted: To discuss natural gas issues Document 29 Sierra Club v.

From: Sent: To: Subject: Rapp, Andrew Thu, 26 Jun 2025 19:49:53 +0000 Brewer, Tracy Accepted: EPNG Arizona Document 42 Sierra Club v.