My fellow methane policy wonks and I have been waiting for EPA’s long-promised supplemental proposed rule. The proposal, which was expected in late summer or fall, had us all sitting on pins and needles as we waited to see–what would EPA come up with for its latest effort to curb methane emissions from the oil and gas industry?
Well, the wait is over, and now that it’s here, there’s a lot to unpack
EPA’s groundbreaking new methane leak detection program
EPA’s first draft of proposed rules, released in November of last year, was a major shift in how the agency thinks about methane reduction. You can find my recap of that first proposed rule here. For the first time, EPA embraced new technology and provided a pathway for methane leak reduction using advanced techniques like aerial monitoring. However, as big of a leap forward as that proposal was, it came up short in a few critical ways.
First and foremost, EPA’s rule was too inflexible–the industry needs choices to design an efficient leak detection program. No inspection frequency or sensitivity will be best for every company’s operations, and setting a one-size-fits-all standard would artificially constrain new technology deployment.
Second, there was no clear basis for how EPA landed on its initial proposal for alternative screening technology. It required six (6) scans per year with an instrument capable of detecting methane emissions of 10 kg/hr, but it didn’t offer any evidence as to why this was the right balance compared to, say 5, 20, or 50 kg/hr, or why six surveys per year were the sweet spot.
Kairos and others argued in comments that EPA needed to allow multiple combinations of instrument sensitivities and survey frequencies to be used and that those combinations be determined through rigorous new modeling tools. Kairos’s comments laid out an example modeling framework using the latest peer-reviewed science and concluded to EPA that more frequent leak surveys at a higher detection limit could eliminate the same or more total methane by identifying the largest leaks faster.
This message was echoed by leading industry, academic, and environmental advocates. That’s because the science is clear: large methane leaks play an outsized role in the total methane footprint.
The framework developed by Kairos to evaluate the trade-offs between frequency and sensitivity clearly showed that six times per year at 10 kg/hr was not the only way to create an effective leak detection program.
But what did EPA ultimately propose?
Let’s take a look.
Facilities with processing equipment onsite
| Survey Frequency (per year) | Required sensitivity* |
| 4x Screening + Annual OGI** | ≤1 kg/hr |
| 6x Screening (No Annual OGI) | ≤2 kg/hr |
| 12x Screening (No Annual OGI) | ≤4 kg/hr |
| 6x Screening + Annual OGI | ≤10 kg/hr |
| 12x Screening + Annual OGI | ≤30 kg/hr |
*90% probability of detection
**OGI – Optical Gas Imaging
For wellhead only facilities
| Survey Frequency (per year) | Required sensitivity* |
| 2x Screening (No Annual OGI) | ≤1 kg/hr |
| 3x Screening (No Annual OGI) | ≤2 kg/hr |
| 3x Screening + Annual OGI | ≤5 kg/hr |
| 4x Screening + Annual OGI | ≤15 kg/hr |
| 12x Screening + Annual OGI | ≤30 kg/hr |
What does EPA’s methane proposal mean for the oil & gas industry?
Now, companies seeking to comply with EPA rules will have a choice in how to achieve that goal. That’s good because it drives competition and innovation and is also good for the environment. An efficient, cost-effective leak detection rule will reduce more methane without imposing excessive costs. EPA’s new proposal is a significant leap forward in both its flexibility for leak detection programs and its level of rigor in calculating the proposed alternative standards.
This rule has a lot more to digest, including the revolutionary new Super Emitter Reduction Program, which will allow community members and other organizations to identify and report large leaks (>100 kg/hr) directly to the industry. The program will also create a challenging new dimension of compliance for companies to navigate.
The experts at Kairos have been working on this rule and are ready to help companies understand how advanced technology can reduce methane, lower their compliance costs, and eliminate possible super emitters that might otherwise get reported by the public.