UNITED STP-.TES ENVIRONMENTAL PRCTECT10r\l AGENCY**REGIO~** VIIi 999 18th STREET-SUITE 500 DENVE8 COLORADO 80202-2405
REF: 8AT-AP FEB 0 2

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### FES051987 CERTIFIED MAIL 

### [ETORNRECEIpT REQUESTED 

### Mr. G. A. Cresswell Mobil Oil Corporation P. O. Box 5444 Denver, Colorado 80217-5444 DearMr. Cresswell: Wehavecompleted our final review of your application to construct and operate amodification to MobilIsMcElmo Creek Unit, and hereby issue conditional approval pursuant to the U. S. Environmental Protection Agency (EPA) Regulations for the Prevention of Significant Deterioration of Air Quality (PSD), 40 CFR 52.21. The conditional permit shall become effective in accordance withArticle IV of the enclosed permit. Construction and operation may not take p1ace if this permit or any part thereof is rejected. Ifyou have any questions, please contactMr. Marius Gedgaudas ofmy staff at (303) 293-1762. Sincerelyyours,

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# - Irwin L. Dickstein, Director Air and Toxics Division Enclosures cc: Burnell Cordner, Director Bureau of Air Quality Utah Department of Health Arlene Luther Navajo NationCONDITIONAL PERMIT TO COMMENCE CONSTRUCTION AND OPERATE 40 CFR 52.21 Prevention of Significant Deterioration of Air Quality Mobil Oil Corporation P. O. Box 5444 Denver, Colorado 80217-5444
I. INTRODUCTION
Mobil 

## on Corporation (hereinafter litheApp1icantil) proposes to construct and**ope~ate** amodification to Mobil's McElmo Creek Unit on the Navajo Indian Reservation in San JuanCounty, Utah. On**t~ay** 13, 1986, the Applicant submitted to the U. S. Environmental Protection Agency, Region VIII (hereinafter litheEPAII ) a Prevention ofSignificant Deterioration (PSD) application to construct the proposed modification pursuant to 40 CFR 52.21. The EPA issued a public notice on December 17,1986, in the San JuanRecord and the Salt Lake Tribune, newspapers of general circulation in the area. The notice proposed to approve the application and issue aconditional air quality permit for the source and providedopportunity for public corrments during the ensuing 30 calendar days. The permit app1ication, the proposed permit, and its supporting analysis were available for pUblicinspection at the Office of the San JuanCounty Clerk in Monticello, the Utah Bureau of Air Quality in Salt Lake City and the EPA Region VIII office in Denver. The only comnents concerning the permit were received from the Applicant and contained only minor clarifications. II. FINDINGS On the basis of information in the administrative record, EPA has determined that: 1. The Applicant is a major source and this modification will result in a significant emission increase of oxides of nitrogen (NOx) and volatile organic compounds (VOC). 2.- The Applicant will meet all of the applicable requirements of the PSD regulations. 3. No applicable emission standard,ambient air quality standard, ormaximum allowable increase, will beviolated by pollutant emissions from this source. 4. EPA has good reason to believe that the Applicant can comply with the conditions of this permit. However, ifthe conditions of this permit are not metby the Applicant, EPA does not assume any risk of losswhich may occur as a resul t of the comnencementofconstruction and operation by the Applicant.III. CONDITIONAL PERMIT TO CONSTRUCT AND OPERATE On the basis of the findings set forth in II above, and pursuant to the authority (as delegated by the Administrator) of 40 CFR 52.21 (i){l), EPA herebyconditionally authorizes the Mobil Oil Corporation to commence construction of the modification to theirMcE1mo Creek Unit as outlined in the Applicant1s permit application ofMay 13, 1986. This approval is expressly conditioned as follOW5: 1. The owner or operator shall abide by all representation, statements of intent, and agreements contained in the application from Mobil Oil Corporation and in all additions and amendments thereto, as follows:
a. May 13, 1986

- PSD PermitApplication for the McElmo Creek Unit C02 Project, Stage 2. b. September 2, 1986

- Supplementary information related to NOx emi5Sion rates. c. November 4, 1986

- Supplementary information correcting

## voe emission rates. 2. Each of the three 1730 hpengines shall belimited to maximum emission rates as follows:

a. NOx - 3.0 g/hp-hr at 15% oxygen on a dry basis and referenced to standard atmospheric conditions. b. 

## voe- 1.0 g/hp-hr of non-methane hydrocarbons at 15% oxygen on a dry basis and referenced to standard atmospheric conditions. 3. Stacktesting for NOx shall heperformed according to Method 20, as modified in .theproposed NSPS for Stationary Internal Combustion Engines (44FR 43152, July 23, 1979). Stack testing for

## voe shall beperformed according to Method 25 or an equival ent procedure. If the Applicant can adequately demonstrate to EPA that emissions from the three engines are essentially the same, a stack test demonstrating compliance for one engine would be sufficent to deem the other two engines in compliance. 4. At all times, including periods of start-up, shutdown, and equipment malfunction, owners and operators shall maintain and operate the facility in amanner consistent with good air pollution control practices for minimizing emissions. Determination ofwhether acceptable operating and maintenance procedures are being used will be basedon information available to the Administrator,which may include, but not be limited to, monitoring results, review of-

.. operating and maintenance**procedures~** and inspection of the source.- 2 -
5. The Applicant shall notify EPA notmore than 48 hours after discovery (or as soon as possible) of excess emissions during periods of start-up, shutdown, equipmentmalfunctions, or process upset. Not more than 10days after discovery, all of the fol1owing shall be provided to EPA in writing:

a. The identity of the stack or other emissionpoint where excess emissions occurred. b. The magnitude of excess emissions expressed in terms of permit conditions.
c. Pertinent operating data during the time of upset. d. The time and duration of excess emissions.

e. The identity of the equipment or process causing the upset and the suspected reasons for the upset. f. Steps and procedures taken during the upset period to minimize excess enissions. g. Steps and procedures taken or anticipated to be taken to prevent recurrence of the upset conditions. h. Ifthe Administrator determines that the information submitted does not evidence malfunction or upset conditions, failure to meet limitations described in this permitwill be considered 

### a violation of the permit. 6. This permit shall expire if construction is notcommenced within the time specified, or once commenced, construction is delayed for the time specified in 40 CFR Section 52.21 (r)(2). 7. All performance testing required pursuant to this permit shall be conducted in accordance with the time schedules and procedures contained in 40 CFR Section 60.8. Performance test results shall be submitted notmore than 45 days after the testing date. 8. Atest protocol outlining a plan for the initial canpliance demonstration tests shall be submitted to EPA 45 days in advance of any .scheduled testing. 9. EPA and its authorized representatives may inspect the permitted facility during normaT business hours for purposes of ascertaining compliance with all conditions of this permit.- 3 -
10. Nothing in this approval shall excuse the Applicant, the owner, and/or operator from complying with all other applicable Federal, State and local regulations. IV. GENERAL This permit is issued in reliance upon the canpleteness and 'accuracy of the information set forth in the Applicant's application to EPA for permission to modify their McElmo Creek plant. On the effective date of this permit, the conditions herein become enforceable by EPA pursuant to any remedies it now has or may have in the future under the Clean Air Act. Each and every condition of this permit is amaterial part hereof and is not severable. This permit is tmnedfately effective, unless you notify this Regional Office, in writing (Attention: Mr. Marius 

### J. Gedgaudas, Air Programs Branch, 8AT-AP), that this permit or a term or condition of it is rejected. Such notice should bemade notmore than ten (10) days after receipt of the permit and should include the reason or reasons for rejection.
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION VIII

# BY:~ __

# 0( · rwlnT. Dicksteln, Director Air and Toxics Division
DATE: 

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