Pollution Prevention and Mitigation: A Risk Based Assessment of LDAR AWP vs Method 21

August 16, 2022

Pollution Prevention and Mitigation

A Risk Based Assessment of LDAR AWP vs Method 21

EPA has defined required methods and work practices to monitor leaks from equipment.  These programs are known as Leak Detection and Repair (LDAR).  These programs must be implemented primarily as a condition of the required air permit and come with federally stipulated monitoring conditions. Currently, 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.

The AWP offers many positive attributes to monitoring for LDAR.  PROtect believes there are many beneficial applications using OGI and expects additional regulations and guidance to be developed in the near future to support various industries. With that being said, the AWP may leave gaps in program implementation and compliance and could be the reason why the largest LDAR programs in the nation have not implemented use of the AWP for their LDAR monitoring. While AWP may be touted as being the more cost-effective solution to find leaks, the pitfalls and considerations associated with the AWP may result in higher cost and additional risk.

Current Approved Monitoring Practice: Method 21

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 a specialized 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.

 What are the benefits of the AWP?        

  • OGI is a more state-of-the-art technology.
  • A greater number of components can be monitored in a day.
  • Monitoring can be done at a distance decreasing the amount of unsafe-to-monitor (UTM) or difficult-to-monitor (DTM) components.
  • Larger leaks may be detected sooner.
  • Equipment that isn’t normally monitored will get monitored under AWP, allowing more leaks to be found
  • Potentially substantial operational improvement to support sustainability and emission reduction programs.

What are the pitfalls?

  • Facility’s permits may not allow AWP without permission from the administrator or regulatory authority, requiring notification or permit modification.
  • From a regulatory standpoint, it is known as the “Alternative Work Practice”, which means, Method 21 is still the preferred and primary means of demonstrating compliance.
  • AWP still requires an annual Method 21 test on all AWP equipment, including DTM Components.
  • The facility will still incur the expense of the tagging, LDAR database, the FIDs, and calibration gas.
  • The AWP cannot be used on all regulated LDAR equipment within your facility.
  • Expenses associated with annual Method 21 monitoring, coupled with rental or purchase cost of a new OGI camera, and including the electronic storage and data collection equipment associated with the AWP, likely prevents a facility from saving time and money using the AWP.

Bottom Line

 PROtect is a fully qualified provider of OGI and AWP services and is committed to providing you with a world class LDAR program. If you are considering a pilot program or study of your facility, including a cost estimate of monitoring with the AWP, please reach out to us as we would appreciate the opportunity to assist you.  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.  Each facility needs to conduct the proper analysis that will allow the facility to determine if AWP makes sense.  If the AWP does make sense, or a facility just wants use OGI for fermenter leak evaluation, PROtect is here to help.  In addition to providing OGI monitoring, PROtect’s diverse service capabilities include:

  • Training – Associated with the AWP implementation and compliance requirements
  • Auditing – Third party audits can be completed for M21 or AWP program monitoring
  • Permitting – May be needed in order to have the approval to switch to the AWP, permitting activities and notifications will be required.
  • Compliance – Implementing OGI as part of a Finding of Violation or Consent Order will require specialized skills to navigate compliance and enforcement activities with the regulatory authority
  • Sustainability services – Associated with the reduction of volatile organic compounds and greenhouse gas emissions

Additional Technical AWP Considerations for Decision Makers

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.  If you are evaluating alternatives, you may not want to change to the Alternative Work Practice, quite yet. PROtect, LLC is certified in OGI monitoring methods, and by working with facilities has gained insight on some of the pros and cons of implementing the AWP, and how various states regard the implementation of the work practice.  PROtect professionals want to step you through this decision-making process to see if it the right decision for your facility.

 Why you might want to consider waiting implementing AWP:

  • One benefit of OGI is it has the ability to detect larger leaks faster, reducing the emissions associated from the larger leaks. However, OGI becomes much less accurate for leak concentrations less than 5000-1500 ppm. For smaller LDAR applications with lower leak rate requirements (such as biofuel facilities), OGI may not be effective in identifying leaks, especially for those subject to VVa.
    • If leaks are found during the Annual M21 check, those components must be rechecked using M21.
    • An increase in leaks found during the Annual M21 check could concentrate maintenance activities to once per year, which may lead to overburdening of resources and associated maintenance activities and cost.
  • Industry opinion exists that in the future actual volumetric leak rates will become the regulated standard, instead of leak counts and concentration. However, this is not the case now, and permits still require compliance with leak concentration and component count.
  • OGI does not yet have leaking vs non leaking emission factors, therefore, the process of calculating emissions for purposes of emission inventory/TRI needs to be considered.
    • If a leak is found during the M21 annual monitoring, one must assume it leaks for the entire year for emissions inventory calculation and reporting purposes. This could increase the annual VOC emissions and may impact permit limits or emission caps for the facility.
  • The technology is still “newer” as such, training requirements are significant for those to use AWP (associated employee/consultant cost/qualified technicians), and there will be a learning curve associated with those adequately knowledgeable in the technology and monitoring methods
  • There are currently only two vendors of OGI cameras that PROtect would recommend using. The cost associated with the FLIR camera is still significantly high.
    • High equipment costs and extensive training requirements essentially eliminates a facility’s ability to implement the AWP inhouse.
  • Is it important to note that the referenced available case studies validating cost savings have only been conducted at refineries and petrochemical plants
  • AWP only replaces the monitoring requirements. Facility owners/operators are still subject to difficult/unsafe to monitor, repair, recordkeeping, and reporting requirements.
  • Appendix K, which is the governing guidance for OGI use, has been proposed for application in the Oil and Natural Gas source category. This protocol for OGI use is still only proposed, and guidance for use in the chemical industry has yet to be developed.

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