UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX 

75 Hawthorne Street 

San Francisco, CA 94105·3901 

JUN 1 4 Z012 

Mr. Patrick E. Flynn 

Vice President, Governmental & Corporate Affairs 

Resolute Natural Resources Company, LLC 

1675 Broadway, Suite 1950 

Denver, Colorado 80202 

RE: Installation and Operation of Triethylene Glycol Dehydrator Unit, McElmo Creek Facility, 

Navajo Nation 

Dear Mr. Flynn: 

Thank you for your letter dated March 17,2011, requesting a determination regarding the applicability of 

certain Clean Air Act requirements, 42 U.S.C. Sections 7401-7671q, to a project that your company is 

proposing to install and operate at the McElmo Creek Facility in Navajo Nation land in San Juan 

County, Utah. 

We understand that your company intends to install and operate the following equipment: 

• one new 25 MMSCFD triethylene glycol dehydration unit with a 1.000 MMBtu/hr reboiler 

burner to replace an existing lower-capacity dehydrator; 

• one new air-assisted, ground level, refractory lined, enclosed flare unit; and 

• three new electric-powered screw compressors with a combined compression capacity of up to 

50 MMSCFD to replace the four existing electric-powered reciprocal compressors. 

Furthermore, we understand that: 

• the new dehydrator will replace the existing dehydrator at the McElmo Creek Facility; 

• emissions from the project will not be routed to the McElmo Creek Facility Main Flare and will 

not cause an exceedance of the existing Consent Decree's Main Flare emission limits [see 

Consent Decree, U.S. v. Mobil Exploration & Producing U.S. Inc. (No. 2:05-CV-319, Central 

District of Utah, June 8, 2005)]; · 

• greenhouse gas emissions from the new project will not exceed the EPA's Greenhouse Gas 

Tailoring Rule's significance thresholds (see 75 Federal Register 31514-31608); 

• McElmo Creek Facility's Prevention of Significant Deterioration ("PSD") significance 

thresholds and existing PSD permit limits will not be exceeded by the replacement of the existing 

dehydrator with the new dehydrator and enclosed flare; and 

• the new project will be located in an area that is in attainment or unclassifiable for all National 

Ambient Air Quality Standards. The table below contains the attainment area permitting 

thresholds as presented in Table 1 of 40 C.P.R. Section 49.153 (Tribal Minor New Source 

Review), the PSD thresholds under 40 C.P.R. Section 52.21, and the project's potential to emit 

("PTE") from the information your company provided. We note that the PTEs are based on 

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Mr. Patrick Flynn- June 14, 2012 

Page2 

emission factors for the specific units or those found in AP-42- Compilation of Air Pollutant 

Emission Factors. 

Emissions Summary 

Project MinorNSR PSD PTEs Thresholds Thresholds (tons (tons per (tons per per year) year) year) 

co 3.01 10 100 

NOx 0.78 10 40 

so2 0.14 10 40 

voc 11.31 5 40 

PM 0.076 10 25 

PMw 0.076 5 15 

PM2.s 0.076 3 10 

Lead 0 0.1 0.6 

Fluorides 0 1 3 

Sulfuric acid mist 0 2 7 

Hydrogen sulfide <0.01 2 10 

Total reduced sulfur N/A 2 10 

Reduced sulfur NIA 2 10 

compounds 

C02e 1,202 NIA 75,000 

As the table shows, the project's PTEs are expected to be below major modification thresholds that 

require a PSD permit. However, the project's PTE for VOC exceeds the minor NSR thresholdrequiring a minor NSR permit. The minor NSR program differs from the PSD program in several ways. 

For one, the degree of technology review to show compliance with national standards may generally be 

less stringent than that for a Best Available Control Technology analysis. Furthermore, an Air Quality 

Impact Analysis for a minor modification permit application may not be required unless the project can 

cause or contribute to a National Ambient Air Quality Standard or PSD increment violation. Based on 

the information your company provided, the issuance of a minor modification permit would obviate the 

need for a PSD permit for a major modification. We recommend that you submit an application for a 

minor NSR permit as soon as possible. 

Also, as you already know, the project after installation will be required to obtain a revised Part 71 

permit from Navajo Nation if a national standard such as a NESHAP requires one. Your company must 
Mr. Patrick Flynn -June 14, 2012 

Page3 

submit an application for such to their office within 12 months after the source becomes subject to the 

permitting program ( 40 C.P.R. § 71.5(a)(l)(i)). We encourage you to continue working with our staff to 

help ensure that the project would comply with any applicable requirements. 

Ifyou have any further questions, please contact Andrew Chew at (415) 947-4197. 

cc: John Jacus, Esq. 

~ Gerardo C. Rios 

Chief, Air Permits Office 

Air Division