Re: White Papers on Methane and Volatile Organic Compound 

(VOC) Emissions in the Oil and Natural Gas Sector

Dear Sir or Madam:

On April 15, 2014, the U.S. Environmental Protection Agency (EPA) Office of Air Quality Planning and Standards 

released for external peer review five technical white papers on potentially significant sources of emissions in 

the oil and gas industry sector. These white papers focus on technical issues covering emissions and mitigation 

techniques that target methane and VOC emissions from compressors, well completions and ongoing 

production of hydraulically fractured oil wells, equipment leaks, liquids unloading, and pneumatic devices. The 

Texas Commission on Environmental Quality (TCEQ) appreciates the opportunity to comment on these white

papers. TCEQ’s comments are provided below.

In general, more data is needed to substantiate and confirm the emission estimates presented in the EPA’s 

white papers. While it is not unusual to establish control requirements based on expected emissions from a 

facility or single source, the studies and emission estimates used in the white papers rely on the EPA’s definition 

of “facility” as established for the EPA’s Greenhouse Gas Reporting Program (GHGRP). 

In general, a “facility” for purposes of the GHGRP means all co­located emission sources that are commonly 

owned or operated. However, the GHGRP has developed a specialized facility definition for onshore production. 

For onshore production, the “facility” includes all emissions associated with wells owned or operated by a single 

company in a specific hydrocarbon producing basin. [1] 

(1 Oil and Natural Gas Sector Hydraulically Fractured Oil Well Completions and Associated Gas during Ongoing 

Production, page 21, footnote 9; Oil and Natural Gas Sector Liquids Unloading Processes page 5, footnote 2; Oil 

and Natural Gas Sector Pneumatic Devices, page 20, footnote 11.)

The use of this definition makes determining emissions from each unit or piece of equipment difficult, if not 

impossible to verify. Since control is usually required for each individual piece of equipment, the lack of this 

information makes evaluating the cost effectiveness of any potential controls or mitigation techniques similarly 

impossible. 

Where the studies referenced in the white papers used a more traditional understanding of the term “facility”, 

meaning each individual piece of equipment, compressor, or controller, the TCEQ has concern about the limited 

data sets used and would recommend additional studies to verify the accuracy and representativeness of the 

numbers and factors derived. The great variation in the composition of oil and gas that exists across different 

fields can result in vastly different emissions profiles and thus additional research is warranted to verify the 

accuracy and representativeness of the expected emissions. Moreover, if the information in the white papers or 

later studies is relied upon to develop required controls or mitigation techniques, the TCEQ recommends 

consideration of a range of controls or techniques that would correlate to the differing standards, or factors 

based on the particular composition or characteristics of the material being handled or processed. This approach 

Steve Hagle <steve.hagle@tceq.texas.gov>

Mon 6/16/2014 6:21 PM

To:OilandGas.Whitepapers <OilandGas.Whitepapers@epa.gov>; 

Cc:Mike Wilson <mike.wilson@tceq.texas.gov>; Mike Hoke <mike.hoke@tceq.texas.gov>; Jayme Sadlier 

<jayme.sadlier@tceq.texas.gov>; Erin Selvera <Erin.Selvera@tceq.texas.gov>; Keith Sheedy <keith.sheedy@tceq.texas.gov>; 

Re: White Papers on Methane and Volatile Organ... - OilandGas.Whitepapers Page 1 of 2

https://pod51045.outlook.com/owa/OilandGas.Whitepapers@epa.gov/ 8/27/2014
would help to ensure the appropriate level of control for the material and provide the flexibility that a “one­sizefits­all” approach cannot achieve. 

Additionally, while the TCEQ encourages innovation and development of new processes and controls for air 

emissions in general, when establishing any standards or requirements it is crucial to rely on proven control 

technologies that are commercially available. The failure to do so may lead to a new standard or control that is 

not achievable for all of the affected facilities. For example, in the evaluation of Compressor Emissions 

Mitigation Techniques for Reciprocating Compressor Gas Recovery, EPA refers to a system developed by REM 

Technology, Inc. that captures gas that would otherwise be vented and routes it back to the compressor engine 

to be used as fuel. However, no cost data was available to properly evaluate the technology as a viable, costeffective control or mitigation technique and, although commercially available, it is unknown if this system is 

available to the scores of facilities that may need to use it if required. The TCEQ encourages the EPA to evaluate 

only proven control technologies that are commercially available in volumes that could support the industry as a 

basis for establishing any future standards or requirements.

If you have any questions about these comments, please contact Mr. Michael Wilson, P.E., Director, Air Permits 

Division, Office of Air, at (512) 239­1922, or at mike.wilson@tceq.texas.gov.

Sincerely,

Steve Hagle, P.E., Deputy Director, Office of Air

Texas Commission on Environmental Quality

steve.hagle@tceq.texas.gov

512­239­1295

Re: White Papers on Methane and Volatile Organ... - OilandGas.Whitepapers Page 2 of 2

https://pod51045.outlook.com/owa/OilandGas.Whitepapers@epa.gov/ 8/27/2014