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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. Danny Powers
Air Quality Program Manager
Southern Ute Indian Tribe Environmental Programs 
P.O. Box 737, Mail Slot #84
Ignacio, Colorado  81137-0737
Via email: dpowers@southernute-nsn.gov

Re:	Red Cedar Gathering Company, South Ignacio Central Delivery Point, 
Permit #SMNSR-SU-000031-2019.004, Proposed Synthetic Minor New Source Review Permit

Dear Mr. Powers:

The U.S. Environmental Protection Agency Region 8 is proposing to issue a revised synthetic Tribal Minor New Source Review (MNSR) permit for the existing Red Cedar Gathering Company (Red Cedar), South Ignacio Central Delivery Point (South Ignacio CDP) on the Southern Ute Indian Reservation. As requested by Red Cedar, this permit would incorporate several changes. First, it would reflect the removal of facility-wide hazardous air pollutant (HAP) and formaldehyde (CH2O) emission limits. Second, it would remove benzene emissions limits for the dehydration units. Third, it would correct the listed site horsepower (hp) rating and remove the CH2O emissions limit for the rich-burn compressor engine and remove the carbon monoxide (CO) and CH2O emissions limitations for each of the seven lean-burn engines. As a result of the requested changes, the four-stroke rich-burn reciprocating internal combustion engine (4SRB RICE) will now be subject to the compliance requirements of 40 CFR part 63, subpart ZZZZ (new, greater than 500 hp, 4SRB RICE, located at a major source of HAP). To better align compliance requirements with subpart ZZZZ, we are proposing to replace the quarterly nitrogen oxides (NOX) and CO monitoring requirements with semiannual NOX and CO performance test requirements. The monitoring frequency of the pressure drop across the catalyst bed would also be changed from once every seven days to once every 30 days. 

An initial public comment period for the proposed revised permit was conducted from June 19, 2020 to July 20, 2020, during which the Southern Ute Indian Tribe Air Quality Program commented that the public notice bulletin, technical support document and proposed revised permit incorrectly stated that proposed changes would not increase allowable emissions at South Ignacio Central Delivery Point. We have corrected such statements, reevaluated the impact of the proposed revisions, conducted an air quality impacts analysis of the increases in allowable emissions from the proposed changes, clarified certain permit conditions and added the tribe as a recipient of required reports. As such, we are making the proposed permit and supporting documents available for a second public comment period.

A public comment period for the proposed permit will begin on October 1, 2020, and end on November 2, 2020.

The proposed permit and supporting documentation are available in the electronic docket at Regulations.gov (Docket ID #EPA-R08-OAR-2019-0290), and we ask 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 the public comment period. Comments may be submitted via email to R8AirPermitting@epa.gov, or through https://www.regulations.gov (Docket ID #EPA-R08-OAR-2019-0290). 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 enclosed proposed permit or technical support documents, please contact Suman Kunwar, of my staff, at (303) 312-6095.   
                                          
                                       Sincerely,
                                                
                                      Carl Daly
                                      Acting Director
                                      Air and Radiation Division
                                      
                                      
Enclosures



