In December 2018, the Wyoming Air Quality Division (AQD) published revisions to their Oil and Gas Production Facilities Permitting Guidance, which will apply to facilities with associated wells that begin production or are modified on or after February 1, 2019. The changes range from clarifying in nature to more significant revisions for pneumatic controllers, modified facilities, and fugitive emissions.

Wyoming air quality regulations require that all new or modified sources or facilities that may result in air emissions obtain a permit and apply Best Available Control Technology (BACT); exemptions to these requirements are very limited. In recognition of the difficulties inherent in estimating emissions at oil and gas production sites prior to start up, the AQD established a permitting program specifically for these operations. This program provides for the start up or modification of some oil and gas production facilities prior to permitting, as long as specified emission control requirements are met. Wyoming calls this "Presumptive BACT."

Wyoming's Oil and Gas Production Facilities Permitting Guidance ("Guidance") is a comprehensive document that describes what the AQD considers to be Presumptive BACT for typical production site emission sources, as well as give direction for how to prepare permit applications and estimate emissions.

Major changes to the Guidance

  • Industry requested that intermittent bleed pneumatic controllers, in addition to low and zero bleed pneumatic controllers, be considered Presumptive BACT. The AQD reviewed studies that indicated properly maintained intermittent controllers actuate less frequently over time as production declines, and emit less than low bleed controllers over their lifetime. As a result, the Guidance now specifies that intermittent bleed pneumatic controllers are Presumptive BACT, and no longer are subject to the limit of six (6) standard cubic feet per hour (scf/hr).
  • The definition of "modified facility" has been significantly revised. AQD removed activities not associated with increased emissions from the definition, including acidizing and CO2 flood/water flood. They also established an emission threshold for when fracturing, recompletion, or introduction of artificial lift at an existing well would be considered a "modified facility". The new definition is an important change that operators should review carefully to understand when permitting and Presumptive BACT is triggered.
  • AQD has specified semiannual monitoring in accordance with 40 CFR Part 60 Subpart OOOOa (as published in the Federal Register on June 3, 2016) as Presumptive BACT for fugitives. In the Upper Green River Basin, if fugitive emissions exceed 4 tons per year of VOCs, the operator must also submit a Fugitive Emissions Monitoring Protocol to the State for approval.

The Guidance was first published in June 1997 and has gone through several revisions. It defines Presumptive BACT in three different areas of the state; areas in the southwest part of the state which have experienced difficulties with ozone attainment have more stringent standards than in the rest of the state. The Guidance does not apply to greenhouse gases or "major" sources. Also worth noting is that Presumptive BACT is not defined for sour oil and gas production sites (except in limited circumstances), reciprocating internal combustion engines greater than 50 horsepower, or other specified exceptions when the AQD has determined that emissions are known or predictable. For these activities preconstruction permitting is required. Owners and operators also have the option of going through preconstruction permitting as an alternative to following the Guidance.

The new Guidance, as well as a Fact Sheet and the agency's response to comments on the draft guidance released in August 2018, are available on the Wyoming AQD website. If you have questions about the Guidance or permitting in Wyoming, please contact Lori Bocchino in Trinity's Wyoming office at (307) 421-0021.