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 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
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REGION 8
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1595 Wynkoop Street
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Denver, CO   80202-1129
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Phone 800-227-8917
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www.epa.gov/region8

Ref:  8ARD-PM

Mr. Gerald Wagner 							
Environmental Director
Blackfeet Tribe
457 Hospital Road
Browning, Montana  59417

Re:	NorthWestern Energy Corporation, Meriwether Compressor Station, 
	Permit # SMNSR-B-000005-2022.003, Proposed Synthetic Minor New Source Review Permit

Dear Mr. Wagner:

The U.S. Environmental Protection Agency Region 8 is proposing to issue a permit in accordance with the Tribal Minor New Source Review (MNSR) Permit Program at 40 CFR part 49, for NorthWestern Energy Corporation's proposed construction and operation of one maximum 2,500 horsepower compressor engine at the existing Meriwether Compressor Station. The purpose of the compressor engines is to take natural gas from the transmission pipeline to use as fuel in order to further boost compression along the pipeline. The proposed project is estimated to be a synthetic minor source of criteria pollutants with respect to the Clean Air Act title V operating permit program at 40 CFR part 71.

The proposed permit contains emissions limitations, associated monitoring, recordkeeping and reporting requirements for the new pollutant emission-generating unit proposed to be approved for construction and installation, as well as our review of existing relevant regulations and existing federal and state permits for similar types of operations. 

A public comment period for the proposed permit will begin on September 29, 2022, and end on October 31, 2022. 

The proposed permit and supporting documents are available in the electronic docket at regulations.gov (Docket ID # EPA-R08-OAR-2022-0345), and we ask you that you please assist members of the public who contact you with instructions on how to access the material available for public review until the end of public comment period. Comments may be submitted via mail, via email to R8AirPermitting@epa.gov, or through https://www.regulations.gov (Docket ID #EPA-R08-OAR-2022-0345). In addition, we have provided copies of the bulletin board public notice announcement and would appreciate it if you could post this announcement in prominent locations in your area. All of these documents will also be available for review in electronic format on our website at: https://www.epa.gov/caa-permitting/caa-permit-public-comment-opportunities-region-8.  




If you have any questions concerning the proposed permit or technical support document, please contact Claudia Smith, of my staff, at (303) 312-6520 or at smith.claudia@epa.gov.   

						Sincerely,
                                    
						Monica Morales
                              Acting Director
                                    Air and Radiation Division



