AWP vs. Method 21

Nov 30, 2021

AWP vs. Method 21

As it’s currently written, the Alternative Work Practice (AWP) is not the most cost-effective method to use for your LDAR compliance.



EPA has defined required methods and work practices to monitor leaks from equipment.  These programs are known as Leak Detection and Repair (LDAR).  Current most regulatory required monitoring is accomplished using EPA Method 21.  Advancements in technology allow for alternative monitoring methods to identify leaks using optical gas imaging (OGI). This Alternative Work Practice (AWP) can be approved for monitoring programs required in all subparts 40 CFR parts 60, 61, 63, and 65.


Current Approved Monitoring Practice

Current regulations require the use of a flame-ionization detector (FID) or photo ionization detector (PID) instrument which meets the performance specifications of EPA Reference Method 21. Using a portable instrument capable of detecting VOC and HAP leaks emissions, a trained technician manually samples equipment leak interfaces to detect the presence of leaks.  Applicable subparts define the leak rate definition, frequency of monitoring, as well as components subject to monitoring (e.g., pumps, valves, connectors, and closed vent systems).  Regulated components are “tagged” and placed in an inventory to assist in the monitoring on each applicable piece of equipment.


Alternative Work Practice for Monitoring

The AWP allows facilities to identify leaking equipment using Camera instead of an FID or PID as prescribed in 40 CFR part 60, Appendix A-7 (i.e., a Method 21 instrument). Optical gas imaging is the use of a special thermal infrared camera to visualize leaks from organic gases.


Is AWP the right choice for you?

There is a reason why the largest LDAR programs in the nation have not implemented use of the AWP for their LDAR monitoring. While some may tout AWP as being the more cost-effective solution to find leaks, there are several pitfalls associated with the AWP, which may be why EPA continues to evaluate the AWP and alternative methods.


On November 2, 2021, EPA unveiled a proposed New Source Performance Standard (NSPS) specifically intended to set emission guidelines to reduce GHG and other pollutants from the Oil and Natural Gas industries only.


What are the benefits? 

  • OGI is a more state-of-the-art technology.
  • A greater number of components can be monitored in a day, when compared to traditional Method 21.
  • Monitoring can be done at a distance decreasing the amount of unsafe-to-monitor (UTM) or difficult-to-monitor (DTM) components.
  • PROtect implements OGI technology at several facilities currently.
    • This work is performed currently for several upstream oil and gas clients where those

facilities are not required to conduct an annual Method 21 inspection.



What are the pitfalls?

  • Most facility’s permits do not allow AWP without permission from the administrator or regulatory authority.
    • A facility would need to request permission from the state via a Construction Permit approval and modify the Operating Permit in order to be authorized to implement the AWP.
  • The current AWP still requires an annual Method 21 test on all LDAR equipment, including difficult to monitor components which require the scaffold, manlifts and other expensive additional measures to reach and monitor each of those components.
  • Additionally, due to the requirement to perform Method 21 annually, a facility will still incur the expense of the LDAR database, the FIDs, calibration gas bottles, and tagging.
  • Expenses associated with annual Method 21 monitoring, coupled with rental or purchase cost of a new OGI camera (which is approximately $100,000), and including the electronic storage and data collection equipment associated with the AWP, prevents a facility from saving time and money using the AWP.


Bottom Line

PROtect is a fully qualified provider of OGI and AWP services.  If you are considering a pilot program or study of your facility, please reach out to us as we would appreciate the opportunity to assist you with this.  PROtect will continue to evaluate new regulations and more efficient alternatives to save you time and money while keeping you in compliance.   While the use of OGI certainly has its benefits, it may not be the best choice while the annual Method 21 validation remains part of a compliance demonstration. PROtect is committed to each facility’s compliance as well as implementing state-of-the-art technology when it makes sense for a customer’s operations.

If you are evaluating your options, please contact our compliance experts.



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