UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

AIR, PESTICIDES & TOXICS MANAGEMENT DIVISION

61 Forsyth St., S. W.

Atlanta, Georgia 30303

FACT SHEET – July 9, 2014

ACTION: Preliminary Determination and Draft Outer Continental Shelf (OCS) Air 

Permit, OCS-EPA-R4012-M1, for Statoil Gulf Services, LLC (Statoil), 

DeSoto Canyon Drilling Exploration Project

Public Notice & July 9, 2014: Publication in the Panama City News 

Comment Period: Herald, Mobile Press Register, Pensacola News Journal, Florida 

Administrative Code and Register, emails to the OCS public notice list,

www.regulations.gov, and the EPA Region 4’s website at: 

http://www.epa.gov/region4/air/permits/ocspermits/ocspermits.html.

 

August 8, 2014: Close of Public Comment Period. If a public hearing is held, 

the public comment period will automatically be extended to the close of the 

public hearing.

Public Hearing: If there is a significant degree of public interest, a hearing will be held

August 14, 2014, from 5:30 pm – 7:00 pm at:

Bay County Public Library

898 W 11th St 

Panama City, FL 32401

(850) 522-2119.

If a public hearing is held, EPA staff will be available prior to the hearing, 

from 4:00-5:30 pm to answer questions and provide additional information on 

this proposed action during an informal public information session. 

Project: Statoil has applied for a modification of permit No. OCS-EPA-R4012, which 

was issued by EPA Region 4 on October 28, 2013 pursuant to section 328 of 

the Clean Air Act (CAA). The permit regulates air pollutant emissions from a 

proposed exploratory drilling operation within the eastern Gulf of Mexico of 

the OCS. The project, which has not yet begun operations under the existing 

permit, will include mobilization and operation of one of two deep water 

drilling vessels, the Maersk Developer or the Transocean Discoverer 

Americas, and associated crew and support vessels. Drilling operations may 

occur for up to180 days per year for a period of five to ten years. The proposed 

project is for exploratory drilling only and does not include the establishment 

of any permanent production platforms. 

Proposed Changes: Statoil has requested that the permit be amended to include best available 

control technology (BACT) limits for particulate matter with an aerodynamic 

diameter less than or equal to 2.5 microns (PM2.5), particulate matter with an 

aerodynamic diameter less than or equal to 10 microns (PM10) and volatile 

organic compounds (VOC) as well as revised BACT limits for nitrogen oxides

(NOX) for engines on the Maersk Developer drilling vessel based on recent 

source test data for these pollutants that was not available at the time of 
permitting. The respective control technology determinations for NOX

emissions from these engines are not being revised. However, determinations 

for control technologies related to VOC and particulate emissions (PM) are 

added to the permit. 

Statoil is also requesting that the permit be modified to include additional lease 

blocks in the same eastern Gulf of Mexico area, which meet location criteria

detailed in the draft permit and preliminary determination. Proposed language 

has been added to the permit to allow this flexibility for the Developer drilling 

vessel. Written notification to the EPA of all drilling locations prior to the 

commencement of operations remains a condition of the modified permit.

The requested permit modification does not constitute a change in the emission 

units or in operation of the source, nor does it waive any applicable air quality 

standards or requirements. While Statoil has made preparations to drill, 

including source testing, Statoil has not yet begun drilling operations on the 

lease blocks covered by the permit. This action is a proposed modification to 

include BACT limits for PM2.5, PM10, and VOCs and revise BACT limits for 

NOX for engines on the Developer to reflect data that is more representative of 

actual drilling operations, and to allow the Developer’s operations to be 

conducted in additional lease blocks subject to specific criteria. Permit 

conditions unrelated to the Developer’s updated BACT limits and operating 

location have not been modified in this draft permit except where necessary for 

clarification or to correct typographic errors.

Public comments are being accepted for these proposed changes only.

The EPA has completed review of Statoil’s application to modify the existing 

permit in addition to all supplemental materials provided and is proposing to 

issue Permit Number OCS-EPA-R4012-M1 to Statoil for a multi-year 

exploratory drilling program subject to the terms and conditions described in 

the draft permit. This project is considered a major source under the applicable 

Prevention of Significant Deterioration (PSD) regulations 40 CFR part 52.21 

and is subject to the title V program at 40 CFR part 71. The permit 

incorporates applicable requirements from the federal PSD and title V 

operating permit programs, New Source Performance Standards (NSPS), and 

National Emission Standards for Hazardous Air Pollutants (NESHAP) as 

required by the OCS air quality regulations in 40 CFR part 55.

Project Location: The Transocean Discoverer Americas will operate in the DeSoto Canyon area 

lease blocks 143, 187, 188, 230, 231, 625, 669, 670, 671, 715, 716, 759, 760, 

and 804. The Maersk Developer will operate in the same DeSoto Canyon area 

or in any eastern Gulf of Mexico area located further from the Breton 

Wilderness Class I area, east of longitude 87.5, west of the Military Mission 

Line (86°41’ west longitude), outside of the current Congressional moratoria 

area as specified by the Gulf of Mexico Energy Security Act of 2006, and not 

within 75 nautical miles of the state seaward boundary of Florida. These lease 

blocks are located in OCS waters of the Gulf of Mexico east of longitude 

87.5°, approximately 160 miles southeast of the mouth of the Mississippi 

River and 200 miles southwest of Panama City, Florida. The northwest corner 

of lease block 143, the closest point within the project area to any state’s 
shoreline, is located on OCS waters of the Gulf of Mexico east of longitude 

87.5 o W at latitude 28.85o N and longitude 86.42 o W. It is located beyond the 

area restricted by the Gulf of Mexico Energy Security Act Moratoria, which 

extends approximately 100- 125 miles off the coast of Florida.

Authority: EPA Region 4 is the agency responsible for implementing and enforcing CAA 

requirements for OCS sources in the Gulf of Mexico east of longitude 87.5°W.

The Department of Interior, Bureau of Ocean Energy Management, is the lead 

agency for leasing and drilling approvals, as well as implementation of the 

Clean Air Act west of 87.5° longitude.

Emissions: The following table lists the PTE for each regulated NSR pollutant from the 

Developer for which Statoil is seeking a new or revised BACT limit based on 

October 2013 source testing of the eight main generator engines, as well as the 

significant emission rate for these pollutants. 

 

 Potential to Emit for Regulated NSR Pollutants Based on Source Testing

 1 NOX and VOC are the measured precursors for the criteria pollutant ozone. NOX & SO2 are precursors for PM2.5.

A full air quality impact analysis was performed for the revised operation. A 

summary of the results of the air quality impact analysis is available in the 

preliminary determination (see additional information below).

Control Technology: Statoil is required to apply BACT for emissions of 

NOX, VOC, PM10, and PM2.5 while using the Developer to conduct activities 

under this permit. BACT for this project will include the use of engines with 

intake air cooling and turbo chargers, open crankshaft ventilation systems, 

good combustion and power management practices, and enhanced engine 

performance management and maintenance on the drilling vessels’ diesel 

engines. BACT for this project includes, among other things, the use of ultralow sulfur diesel fuel to limit sulfur dioxide and particulate emissions.

Additional Information: The draft permit and preliminary determination/statement of basis documents 

that explain the revised permit conditions are available on EPA Region 4’s 

website at: http://www.epa.gov/region4/air/permits/ocspermits/ocspermits.html

EPA Contact: For questions regarding the draft permit and public hearing, contact:

Lori Shepherd

Air Permits Section

Air, Pesticides and Toxics Management Division

U.S. EPA Region 4

Pollutant Scenario 1 

(Developer) 

Tons per Year

Significant Emission 

Rate 

Tons per Year

PSD Review 

Required

NOX

1

554.05 40 Yes

VOC175.65 40 Yes

PM10 17.47 15 Yes

PM2.5 16.03 10 Yes
61 Forsyth Street, SW

Atlanta, GA 30303

(404) 562-8435

Email: shepherd.lorinda@epa.gov

Comments on the draft permit and requests for a public hearing should be addressed to:

U.S. EPA Region 4

Air Permits Section, APTMD

61 Forsyth Street, SW

Atlanta, GA 30303

Attn: Rosa Yarbrough

Email: R4OCSpermits@epa.gov