UNITED STP-.TES ENVIRONMENTAL PRCTECT10r\l AGENCY

REGIO~ VIIi

999 18th STREET-SUITE 500

DENVE8 COLORADO 80202-2405

REF: 8AT-AP

FEB 0 2 rm R'EOItVf!1

AiR QUAU, {

FES 051987

CERTIFIED MAIL

[ETORN RECEIpT REQUESTED

Mr. G. A. Cresswell

Mobil Oil Corporation

P. O. Box 5444

Denver, Colorado 80217-5444

Dear Mr. Cresswell:

We have completed our final review of your application to construct and

operate a modification to MobilIs McElmo 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 with Article

IV of the enclosed permit. Construction and operation may not take p1ace if

this permit or any part thereof is rejected.

If you have any questions, please contact Mr. Marius Gedgaudas of my staff at (303) 293-1762.

Sincerely yours,

~~@A--"---4- Irwin L. Dickstein, Director

Air and Toxics Division

Enclosures

cc: Burnell Cordner, Di rector

Bureau of Air Quality Utah Department of Health

Arlene Luther

Navajo Nation
CONDITIONAL PERMIT TO

COMMENCE CONSTRUCTION AND OPERATE

40 CFR 52.21

Preventi on of

Significant Deterioration of Air Quality

Mobil Oil Corporation

P. O. Box 5444

Denver, Colorado 80217-5444

I. INTRODUCTION

Mobil on Corporati on (herei nafter lithe App1 icantil) proposes to construct and ope~ate a modification to Mobil's McElmo Creek Unit on the Navajo Indian

Reservation in San Juan County, Utah.

On t~ay 13, 1986, the Applicant submitted to the U. S. Environmental Protection

Agency, Region VIII (hereinafter lithe EPAII

) a Prevention of Significant 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 Juan Record

and the Salt Lake Tribune, newspapers of general circulation in the area. The

notice proposed to approve the application and issue a conditional air quality permit for the source and provided opportunity for public corrments during the

ensuing 30 calendar days. The permit app1ication, the proposed permit, and

its supporting analysis were available for pUblic inspection at the Office of

the San Juan County 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, or maximum

allowable increase, will be violated 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, if the conditions of this permit are

not met by the Applicant, EPA does not assume any risk of loss which may occur as a resul t of the comnencement of constructi on and operati on by the Appl i cant.
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

hereby conditionally authorizes the Mobil Oil Corporation to commence

construction of the modification to their McE1mo Creek Unit as outlined in the

Applicant1s permit application of May 13, 1986. This approval is expressly conditi oned as foll OW5:

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

foll ows:

a. May 13, 1986 - PSD Permit Application for the McElmo Creek Unit

C02 Project, Stage 2. b. September 2, 1986 - Supplementary information related to NOx emi 5S i on rates.

c. November 4, 1986 - Supplementary information correcting voe

emission rates.

2. Each of the three 1730 hpengines shall be limited 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. Stack testing for NOx shall he performed according to Method 20,

as modified in .the proposed NSPS for Stationary Internal Combustion

Engines (44 FR 43152, July 23, 1979). Stack testing for voe shall

be performed accordi ng 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 a manner consistent with good air pollution control

practices for minimizing emissions. Determination of whether

acceptable operating and maintenance procedures are being used will be based on 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.
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5. The Applicant shall notify EPA not more than 48 hours after

discovery (or as soon as possible) of excess emissions during

periods of start-up, shutdown, equipment malfunctions, or process

upset. Not more than 10 days after discovery, all of the fol1 owi ng shall be provided to EPA in writing:

a. The identity of the stack or other emission point where excess

emissions occurred.

b. The magnitude of excess emissions expressed in terms of permit conditi ons.

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. If the Administrator determines that the information submitted

does not evidence malfunction or upset conditions, failure to

meet limitations described in this permit will be considered a

violation of the permit.

6. This permit shall expire if construction is not commenced 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 not more than 45 days after the testing date.

8. A test protocol outlining a plan for the initial canpliance demonstration tests shall be submitted to EPA 45 days in advance of

any .schedul ed testi ng.

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 a material 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

be made not more 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: ;(- /J--f7