New Mexico Board (EIB) Approves Ozone Rules

Updated: Apr 27

The New Mexico Environment Department (NMED) petitioned a new ruling with the Environmental Improvement Board (EIB) for ozone precursors in May 2021. Approximately 2 years after stakeholder review and public outreach, the rule has been approved. This new ozone precursor rule follows the Energy, Minerals and Natural Resources Department’s methane rule that recently went into effect and will work in conjunction to reduce methane emissions for the state of New Mexico. The rule applies to counties under the board’s jurisdiction that exceed 95% of NAAQs for ozone. To learn more about ground-level ozone and the EPA’s recent decision to maintain current NAAQS thresholds for the criteria pollutant, check out our post here.

Leak Detection

Of particular importance are the changes/implementation of LDAR (leak detection and repair). Well sites, tank batteries, gathering and boosting stations, natural gas processing plants and transmission compressor stations, are subject to LDAR. Components in water and air service are not subject to LDAR, e.g., instrument air pneumatics, freshwater tanks, etc.

Per NMAC, leak detection methods include:

· AVO (audio, visual and olfactory)

· Method 21

· Optical Gas Imaging


The AVO inspection frequency is set by facility throughput. Sites with greater than 10 barrels of oil per day or an average of 60 MCF/d of natural gas, shall conduct AVO inspections on a weekly basis. For sites equal to or less than 10 bbl/day the survey requirements are monthly. The requirements for “The Proximity Proposal,” i.e., well sites within 1,000 feet of an occupied area, have been simplified to quarterly monitoring. Leaking equipment detected during the AVO inspections, must be tagged, and repaired; however, the 3-day repair requirement has been waived.

Method 21 & OGI The U.S. EPA Method 21, or OGI (optical gas imaging) are required per a site's potential to emit (PTE) of VOCs. The following is excerpted from from the rule:

For well sites and standalone tank batteries:

  • annually at facilities with a PTE less than ten tpy VOC

  • semi-annually at facilities with a PTE equal to or greater than ten tpy and less than twenty-five tpy VOC

  • quarterly at facilities with a PTE equal to or greater than twenty-five tpy VOC.

For gathering and boosting stations and natural gas processing plants:

  • semiannual at facilities with a PTE less than 25 tpy VOC

  • quarterly at facilities with a PTE equal to or greater than 25 tpy VOC.

Repair requirements for leaks detected during Method 21 or OGI are not new to those who have been subject to leak detection and repair rules, such as OOOOa. Leaks need to be repaired within 30 days of discovery and must be re-monitored no later than 15 days after the repair.

Impacts of the rule will result in significant reductions of VOC and NOx, (ozone precursor pollutants), reductions in smog, and improved ambient air quality. The NMED predicts the ruling will reduce volatile organic compounds (VOCs) by approximately 112,915 tpy and nitrogen oxides (NOx) by approximately 18,008 tpy. This would be the equivalent of taking 8 million passenger cars off the road per year. Furthermore, this rule coincides with New Mexico’s goal of achieving their GHG reduction target of 45% statewide by 2030.