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 l eaks, 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 confi rm 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 E PA’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 co

- located emission sources that are commonly owned or operated. However, the GHGRP has devel oped 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, footnot e 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 evaluati ng 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, c ompressor, 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 t hat 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 late r 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 would help to ensure the appropriate level of control for the material and provide the flexibility that a “one

- size

-fits

all” approach cannot achieve. Additionally, while the TCEQ encoura ges 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 t o 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, cost

- effective 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 volume s 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) 239

- 1922, o r 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

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- 239

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