Public Notices: MountainWest Pipeline, LLC (F000687/A0015852)

Wyoming Department of Environmental Quality  | view as a webpage

Wyoming Department of Environmental Quality

Public Notices: March 30, 2024




Electronic copies of all public notices, permit application analyses, and permit applications are now available through the IMPACT Public-Facing Website OpenAir.  For more information on OpenAir, please visit our website here


The Division of Air Quality, proposes to approve the following requests:

MountainWest Pipeline, LLC (F000687, P0037348):  

CHAPTER 6, SECTION 2 CONSRUCTION/MODIFICATION PERMIT - Department of Environmental Quality, Division of Air Quality PUBLIC NOTICE: In accordance with Chapter 6, Section 2(m) of the Wyoming Air Quality Standards and Regulations, notice is hereby given that the State of Wyoming, Department of Environmental Quality, Division of Air Quality, proposes to approve a request by MountainWest Pipeline, LLC to modify the CKN-Rock Springs Station with the addition of one (1) 13,088 hp Solar Mars 100-16000S gas turbine engine (ENG020), one (1) 2,264 hp Caterpillar G3516 emergency generator engine (ENG021), compressor blowdown emissions (BVC001, BVC005, BVC008, and BVC013), and an increase in fugitive components (FUG003). Additionally, MountainWest Pipeline, LLC proposes to modify the facility by revising operating hours from 250 to 100 hours per year for the following emergency generator engines: one (1) 521 hp Waukesha F-2895GSIU (ENG003), two (2) 435 hp Cummins GTA14-G2 (ENG010 and ENG015), and one (1) 1,334 hp Cummins GTA50G3 (ENG017); as well as including startup and shutdown emissions for the following existing gas turbines: one (1) 12,860 hp Solar Mars 100-15000S (ENG016), one (1) 13,088 hp Solar Mars 100-16000S (ENG018), and one (1) 4,680 hp Solar Centaur 40-4700S (ENG002). The CKN-Rock Springs Station is located in the NW ¼ SE ¼ of Section 24, T18N, R106W, approximately eight (8) miles southwest of Rock Springs, in Sweetwater County, Wyoming.

For the duration of the public comment period, the permit application, the agency’s analysis, and the public notice are available for public inspection online at, utilizing facility ID F000687 and permit number P0037348 under permits. This material may also be viewed online, at the above URL, utilizing a public computer at the Sweetwater County Library, Green River, Wyoming. Additionally, for the duration of the public comment period a copy of this public notice is available for public inspection at the Sweetwater County Clerk’s Office, Green River, Wyoming.

Written comments may be directed to Nancy Vehr, Administrator, Division of Air Quality, Department of Environmental Quality, 200 West 17th St., Cheyenne, Wyoming 82002 or by fax (307) 635-1784. Please reference A0015852 in your comment. Comments may also be submitted electronically through the Division’s website ( Comments submitted by email will not be included in the administrative record. All comments received by 5:00 p.m., Monday, April 29, 2024 will be considered in the final determination on this application. A public hearing will be conducted only if in the opinion of the administrator sufficient interest is generated or if an aggrieved party so requests. Para español, visite Americans with Disabilities Act: special assistance or alternative formats will be made available upon request for individuals with disabilities. Please provide at least fourteen (14) days before the close of the public comment period for such requests.

                   Please note that the Wyoming Department of Environmental Quality Cheyenne Office has moved. 
                                                                               The new address is:

                                                                               200 West 17th Street
                                                                              Cheyenne, WY 82002