Air emissions management
Download August 21, 2018

Updated Directive 39 (Benzene Emissions) - June 19, 2018

The AER officially released the updated Directive 39 (benzene emissions reporting regulation) on June 19, 2018. It can be found at

We have reviewed the Directive and key issues and changes are summarized in this article.

We submitted a number of clarifications when the draft was released in December, as did CAPP and other parties – these clarifications and the AER responses are outlined at

Executive Summary

This is an abbreviated summary of key changes:

  • There are new DEOS Sheet and Inventory List templates.
  • There are new requirements for the person completing the DEOS and Inventory List ("qualified person") and the senior authority signing off on the inventory list ("person responsible"). Every DEOS needs to be signed by the “qualified person”.
  • The progressive introduction of emissions limits is complete and there is now one table which clarifies them. The emissions limits are consistent with the previous AER published limits.
  • There are many new clarifications regarding controls, including flares, incinerators, VRUs, condensers, and newly-identified controls which route still overhead vapours to the regenerator or a compressor engine. Where a VRU was previously specified with no further clarification, some additional review will likely be needed.
  • An exact distance is required to be reported for residents (including work camps) within 1500 m of the facility, although notification requirements are still applicable for residents within 750 m of the facility. These notification requirements have been clarified in the Directive. Documentation must be maintained verifying that notification was completed.
  • It may be possible to adopt a different extended gas analysis schedule, with justification.

Here are the details:

DEOS / Inventory List

There is a new DEOS Sheet (to be used starting May 1, 2019) which has some significant changes:

  • New layout
  • New graph for refrigeration facilities
  • Requirement to report benzene emissions assuming 365 day/yr operation (fundamentally no change, but just a different way of reporting)
  • Identification of Primary and Secondary Control
  • Signature of Qualified Person (see below)

There is a new Inventory List (to be used starting May 1, 2019) which has some significant changes:

  • Many changes in columns/data
  • Distance to Surface Development identified if below 1500 m
  • Requirement to show AER and Petrinex Identifier
  • Requirement to display glycol circulation rate and wet gas water content
  • Requirement to display methane emissions
  • Significant change in the reporting of controls
  • Requirement to identify prorated benzene limit based on number of operating days (and be below that limit).
  • Signature of Qualified Person and Person Responsible (see below)

There is a new requirement for the DEOS to be completed by a "qualified person" - "A licensee-appointed technical person who has the necessary training, expertise, and technical knowledge of dehydration operations and air emissions management to complete or oversee others completing the tasks to ensure licensee adherence to the requirements of Directive 039." The Directive identifies in detail key competencies in the areas of Operational Data Collection, Benzene Emission Calculation, Reporting, and Communication.

The Inventory List requires signature of both the "qualified person" and the "person responsible for the licensee". A "Person responsible" is "A senior employee of the licensee who represents the licensee and has the authority to allocate funds toward corrective actions and the authority to direct facility operations, including shutting in production (e.g., vice president of operations), in Alberta."

An alternative extended gas analysis schedule may be adopted in the case where the gas sources and benzene content of the gas do not change over time, but this will need to be justified.

Benzene Emissions Limits

  • The progressive introduction of new benzene emissions limits is complete as of Jan 1, 2018, and there is now one table which clarifies the emissions limits (consistent with previous AER updates).
  • Benzene emissions limits for flares/incinerators now include reciprocating engines in this category.
  • The inventory list will now show a pro-rated benzene limit adjusted for actual operating days. On the other hand, the DEOS will show the emissions projected for 365 days/yr operation (fundamentally no difference, just different ways of reporting).
  • Emissions limits are based on actual tonnes emitted in a calendar year. If the limit is exceeded part way through the year, the noncompliance would be required to be reported to the AER immediately.
  • Effective Jan 1, 2021, there will be new site-wide benzene emissions limits. According to the AER, “All source-site emissions limits are for use in the case where there may be benzene-related concerns such as odour and where there may be a need to investigate benzene emissions sources other than glycol dehydrators.”


  • In the new Directive, still overhead vapour recovery to reboiler burner as well as to reciprocating engine have been assigned a maximum benzene emission control efficiency (90% for burner, 95% for reciprocating engine). Coordination with the AER and further testing is required to claim a higher reduction.
  • To claim benzene reductions for a flare, it must be designed as per Directive 60 (Section 7) requirements, including 12 m stack height. There are stack height requirements for incinerators and compressor engine stacks as well.
  • VRU is still an acceptable control, but the licensee must ensure “that no benzene emissions are released to the environment or directed to another control under normal operating conditions.”
  • The new Directive now includes very specific requirements around Condenser system control and testing, including the requirement for "site-specific testing" every five years and requirement to notify AER 2 weeks before a Total Capture Test.
  • Benzene Control Efficiency is defined as A x B, where A is the maximum acceptable benzene control efficiency, and B is the control technology uptime or benzene removal time. For controls such as those that route still vent emissions to a reboiler burner, factor "B" must be determined, which is the reboiler burner uptime. This will reduce the standard 90% reduction efficiency. Also, if (e.g.) a flare is down for a portion of the year, the B factor would be applied to correct the standard 90% flare factor.
  • GHG/methane emissions should be considered when selecting control technology.

Resident and AER Notification

  • An exact distance is required to be reported for residents within 1500 m of the facility (the initial Directive indicated 750 m, and previous communications from the AER indicated 3000 m). Notification is still required for residents within 750 m of residents.
  • Specific resident notification requirements are incorporated in the new Directive, stipulating notification timelines and documentation requirements, as well as a clearer definition of a "close proximity development".
  • The new Directive indicates that the licensee must immediately report a noncompliance to the AER and take immediate steps to bring operations back into compliance.
  • Documentation verifying that notification was completed as required must be kept.

If you have any questions, feel free to contact us at

By James Holoboff, M.Sc., P. Eng.

James has over 30 years of experience in process engineering and emissions management for the chemical and petroleum industries. He brings a strong background in the development and application of computer simulation models to Oil & Gas industry challenges. James worked for Hyprotech/Aspentech for almost 10 years in various capacities including Global Technical Support Manager and Business Development Manager for the Project Services Division. He then spent 5 years providing process engineering and simulation consulting to a number of operating companies and engineering firms. James has been a Managing Partner for Process Ecology for almost 20 years, during this time providing process engineering services, emissions reporting, project management, and software development support. James is a Chemical Engineering graduate from the University of Calgary and holds an MSc in Chemical Engineering from the same institution. In his spare time, when he’s not playing ice hockey or cycling, he is recovering from injuries incurred from those sports.



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