{In Archive} FYI - EPA Letter

Shaheerah Fateen to: Gerardo Rios, Ann Lyons 04/06/2004 11:01 AM

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fyi 

----- Forwarded by Shaheerah Fateen/R9/USEPA/US on 04/06/2004 10:59 AM -----

Shaheerah Fateen

04/02/2004 02:02 PM

To: neil.j.ryan@exxonmobil.com

cc:

Subject: EPA Letter

Neil, attached is the letter I mentioned to you over the phone earlier this week. The purpose of the letter is 

to update the information in the Part 71 application for the McElmo Creek Unit. The letter was mailed 

today. Please let me know if you have any questions. Thanks.

Shaheerah Fateen

U S EPA Region 9, Air Division (AIR-3)

San Francisco, CA 94105

email: fateen.shaheerah@epa.gov

Phone: 415-947-4156

Fax: 415-947-3579
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX

75 Hawthorne Street

San Francisco, CA 94105

March 31, 2004

Neil J. Ryan

Regulatory Compliance Supervisor

ExxonMobil Production Company

U. S. Production

P. O. Box 4358

Houston, Texas 77210-4358

Subject: Request For Information To Update Part 71 Permit Application No. NN-OP 00-07

Dear Mr. Ryan: 

The purpose of this letter is to request information in response to the Part 71 application,

dated March 22, 2000, for the ExxonMobil McElmo Creek Unit (MCU) site. We are currently

drafting the Part 71 (Title V) permit for this facility and reviewing the requirements that may

apply to the source. Below is the information that will allow us determine the federal regulations

that apply to MCU and complete the Part 71 permit for this site. We request that you provide us

with responses by the date listed at the end of this letter.

1. Our records for this facility indicate one natural gas-fired turbine, which was used to

drive natural gas compressors at the site, is located at MCU and that the turbine is subject

to the performance standards for stationary gas turbines under 40 CFR Part 60 Subpart

GG. Please identify the status of the gas turbine. Specifically, identify whether the

emissions unit is currently operating at MCU or whether the unit is no longer operating

and has been removed from the site. If the gas turbine is not operational, identify the date

when the unit was permanently taken out of service.

2. Our records for this facility indicate that a natural gas liquids (NGL) plant was located on

the MCU site. The records also indicate that the plant was subject to the requirements of

40 CFR Part 60 Subpart KKK, which is the performance standards for equipment leaks of

volatile organic compounds (VOC) from onshore natural gas processing plants. Please

identify whether the NGL plant, and its associated equipment, is currently operating at

MCU or whether the plant is no longer operating and has been dismantled and removed

from the site. If the NGL plant is not operational, identify the date when the unit was

permanently taken out of service. 
2

3. Our records indicate that MCU contained affected sources as defined under 40 CFR Part

60 Subpart LLL, which is the performance standards for sulfur dioxide emissions at

onshore natural gas processing. The affected sources include a sweetening unit followed

by a sulfur recovery unit. Please identify whether sweetening units and/or sulfur recovery

units are currently operating at MCU, or whether the equipment are no longer operating

and have been dismantled and removed from the site. If the equipment are not

operational, identify the date when the units were permanently taken out of service. 

4. The Part 71 application for ExxonMobil states that MCU is not subject to the maximum

achievable control technology (MACT) standards under 40 CFR Part 63 Subpart HH,

which applies to oil and natural gas production facilities. The March 22, 2000 Part 71

application states that according to GRI-GLYCalc calculations, the facility is not major

for HAPs for the TEG reboiler. However, according to the GRI-GLYCalc attachment of

an April 30, 1999 letter from Mobil Exploration & Producing U. S. Inc. to the EPA,

uncontrolled emissions of n-hexane were estimated to be 12.2 tons per year, which

exceeds the major source threshold of 10 tons per year for any single hazardous air

pollutant and could potentially subject the glycol dehydrator and any other affected units

to the Subpart HH MACT standard. The compliance deadline for the Subpart HH was

June 17, 2002. At this time, any affected sources are required to comply with the

requirements under the MACT standard. 

Please provide the following information in which our office will use to determine

whether Subpart HH applies. 

(a) Identify each glycol dehydration unit, storage vessel with the potential for flash

emissions, any ancillary equipment that are intended to operate in volatile

hazardous air pollutant service as defined under § 63.761 and are located at the 

natural gas processing plant; and any compressors intended to operate in volatile

hazardous air pollutant service as defined under § 63.761 and are located at the

natural gas processing plant.

(b) Describe the current operation any glycol dehydrators, storage vessel with the

potential for flash emissions, any ancillary equipment that are intended to operate

in volatile hazardous air pollutant service as defined under § 63.761 and are

located at the natural gas processing plant; and any compressors intended to

operate in volatile hazardous air pollutant service as defined under § 63.761 and

are located at the natural gas processing plant.

(c) Complete the analysis under § 63.760(a). To estimate the emissions, you may use

the model GRI-GLYCalcTM version 3.0 or higher and the procedures presented in

the associated GRI- GLYCalcTM Technical Reference Manual for estimating

major HAP emissions from the TEG dehydrator. 
3

5. The prevention of significant deterioration (PSD) permit issued in 1991 contains

enforceable requirements for the equipment listed in Attachment A. Of this equipment,

only one TEG reboiler is listed in the Part 71 application. Aside from the equipment

identified in items 1 through 4 of this letter and the one TEG reboiler identified in the

Part 71 application, please confirm that the equipment listed in Attachment A and that are

not listed in the Part 71 permit application have been dismantled and removed and are no

longer operating at MCU. If the equipment are not operational, please identify the date

when the emissions units were permanently taken out of service. If any of the equipment

has not been removed, please inform us of the status of the equipment.

6. Please identify any of the following equipment that is located at MCU that either contains

or contacts a fluid (liquid or gas) containing benzene: pumps, compressors, pressure relief

devices, sampling connection systems, open-ended valves or lines, valves, connectors,

surge control vessels, bottoms receivers, and control devices or systems which contacts

benzene. Of the equipment identified, identify which equipment that either contains or

contacts a fluid (liquid or gas) that is less than 10 percent by weight of benzene as

determined using ASTM Method D-2267. (See 40 CFR 61.245(d).)

We request that you submit this information by April 19, 2004 in order for us to

determine whether the above federal regulations apply to MCU. If you need additional time

please contact our office as soon as possible. The above information is necessary to complete the

draft Part 71 permit for MCU. We appreciate your assistance and cooperation in providing this

information. 

Please contact me at (415) 972-3974 or Shaheerah Fateen, of my staff, at (415) 947-4156

or fateen.shaheerah@epa.gov if you have any questions or concerns. 

Sincerely,

/Signed by Gerardo C. Rios/

Gerardo C. Rios

Chief, Permits Office

Enclosure

cc: Jennifer Wilder Baird, ExxonMobil Production Company

Irene T. Garcia, ExxonMobil Production Company

Wilson Laughter, Navajo Nation

Christopher Lee, Navajo Nation
4

Attachment A

Table 1 of Pollutant-Emitting Equipment Authorized 

Under the April 1991 EPA PSD permit for MCU

Emission Point Size Listed In Part 71 Application?

T4500 Gas Turbine 4390 HP Not listed

Ingersoll Rand Engine 491 HP Not listed

Fairbanks Morse Engine 1712 HP Not listed

Fairbanks Morse Engine 1712 HP Not listed

Fairbanks Morse Engine 1848 HP Not listed

Fairbanks Morse Engine 1848 HP Not listed

DPC-540 470 HP Not identified in Part 71 application

Waste Heat Recovery Unit 11.0 MMBtu/hr Not listed

HC Liquid Reboiler 1.0 MMBtu/hr Not listed

Heat Medium Heater 4.0 MMBtu/hr Not identified in Part 71 application

TEG Reboiler 0.33 MMBtu/hr Listed as TEG Reboiler

TEG Reboiler 0.33 MMBtu/hr Not listed

TEG Reboiler 0.33 MMBtu/hr Not listed