A well-documented record can be critical in demonstrating compliance, rebutting inaccurate interpretations of data, and positioning the facility effectively in the event of regulatory scrutiny or litigation.
By Michael Mims
In late 2025, landfill operators saw satellite-based methane detection move from emerging technology to regulatory reality, with states beginning to tie compliance obligations directly to remotely detected methane plumes.
In November 2025, California approved amendments to its Landfill Methane Regulation requiring operators to respond to remotely detected methane plumes. Weeks later, Colorado adopted a similar rule. And Oregon lawmakers passed legislation requiring a major landfill to adopt advanced methane detection technologies such as drones and satellite-based monitoring.
At roughly the same time, private satellite operators—including Carbon Mapper and GHGSat—continued launching new methane-detection systems, which they claim can detect, map, and quantify methane emissions from landfills. Meanwhile, federal regulators have increasingly adopted a deregulatory approach to methane policy.
This article summarizes state regulators’ recent embrace of satellite-based methane detection at landfills and provides an attorney’s perspective on how landfill operators can mitigate their risk in the face of this evolving legal and regulatory landscape.
The Historical Standard and its Limits
For decades, landfill methane compliance has been built around quarterly surface emissions monitoring (SEM), paired with efforts to model estimated methane generation and capture.
Critics have long argued that these historical standards provide a limited snapshot of methane activity at landfills. Common criticisms of SEM are that it is conducted only at portions of a landfill, is done infrequently, is heavily influenced by human behavior, and is not designed to quantify total emissions. Likewise, modeling efforts may depend on assumptions about waste composition, decay rates, and gas collection efficiency.
Emerging Technologies: Monitoring by Aircraft, Drones, and Satellites
Over the past several years, multiple private companies have invested heavily in technology aimed at monitoring methane emissions at landfills based on methane’s detectable spectral signature, as viewed from a satellite, aircraft, or drone. In simple terms, certain sensors can “see” methane by measuring how sunlight is absorbed as it passes through a methane plume. These companies claim that their data can reveal where the plume originated and, in some cases, how much methane is being released.
Using this technology, a 2024 Science study used airborne imaging to survey hundreds of landfills across 18 states. The study noted:
• Methane plumes were detected at 52 percent of surveyed landfills;
• Emissions were often persistent across multiple observations, sometimes lasting months or years;
• A subset of landfills exhibited large, concentrated point-source emissions; and
• Measured emissions showed weak correlation with reported emissions under EPA’s Greenhouse Gas Reporting Program.
The study also highlighted that methane emissions are often tied to specific, dynamic conditions, including working face operations, gas collection system performance, and maintenance and construction activities.
Similarly, a 2025 satellite survey published in Nature noted significant uncertainty in landfill methane emissions worldwide, including a lack of consistent correlation between facility-level observations and reported or modeled emissions. These research findings will inevitably be used as ammunition by state regulators and environmental justice organizations pushing for increased regulation of methane at landfills.
California and Colorado: Using Satellite Data to Trigger Regulatory Obligations
California and Colorado provide two early examples of how state regulators are using remote methane detection to impose obligations on landfill operators. Through its California Satellite Methane Project (CalSMP), the California Air Resources Board (CARB) recently began using satellite data to identify methane plumes and notify operators. CARB claims that the program has already helped identify and resolve 10 large methane leaks, with some repairs occurring within 24 hours.
California is not collecting this data on its own. CARB is contracting with private satellite operators and data analytics partners to obtain methane plume observations. The program is designed to take advantage of the rapidly expanding private fleet of satellites, rather than build a standalone state system. At the same time, CARB has emphasized transparency: plume detections and related information are increasingly being made available through public-facing platforms and dashboards, allowing regulators, operators, and third parties (such as environmental justice groups) to view methane emissions data outside the traditional SEM and GHGRP reporting frameworks.
Crucially, California is using this technology to impose regulatory obligations on landfill operators. Under the November 2025 amendments to the Landfill Methane Regulation, when CARB notifies an operator of a remotely detected methane plume, the operator must
• Conduct targeted monitoring within five days
• Investigate the source of emissions
• Take corrective action if necessary
• Report findings and mitigation efforts
By comparison, Colorado’s Regulation 31 (enacted in December 2025) takes a broader approach. Rather than building the rule around a named state satellite program like CalSMP, Colorado defines “remote methane monitoring” as detections from satellites, aircraft, or mobile monitoring platforms—including those conducted by third parties. Colorado’s explicit reference to third parties is striking. The implication is that these emerging technologies not only expand how methane emissions are measured, but also who can contribute to the evidentiary record.
Regulation 31 requires that any remote detection be conducted with technology approved by the regulator or that has obtained third-party certification under EPA’s Methane Super Emitter Program. As with California’s framework, Regulation 31 provides that, if the regulator notifies a landfill operator of a remotely detected methane emission, the operator must investigate and respond within a short timeframe.
The key point is that California and Colorado are using satellite data not just for information gathering, but also to trigger obligations for the regulated community.
Oregon: Mandating Advanced Detection Technology
Oregon’s 2025 legislation is notable as, rather than focusing on enforcement triggers, it places remote monitoring obligations directly on the landfill operator. Specifically, Oregon has required a single, major landfill to conduct its own advanced methane detection methods, including tools such as drones, aircraft, or satellites. While early drafts of the legislation proposed imposing such obligations to landfill operators broadly, the enacted law applies to one prominent Oregon landfill and goes into effect on January 1, 2027.
Unlike California and Colorado, Oregon has not yet built a broad statewide satellite-triggered enforcement framework. Instead, it is combining a site-specific statutory mandate for advanced methane detection with traditional enforcement pressure to accelerate improved monitoring at a prominent facility.
Third Parties Enter the Fray
Regulators and operators are not the only ones with access to methane plume data, as companies such as Carbon Mapper are increasingly releasing their data to the public. Through Carbon Mapper’s open data portal, observations of alleged methane “super-emitters” are accessible to researchers, journalists, and advocacy groups. Once that data is public, it is almost inevitable that it will be used to pressure both regulators and the regulated community.
For example, UCLA’s Emmett Institute—an academic center active in climate advocacy—publishes an annual list of its “Top 25 Methane Plumes,” based on data provided by Carbon Mapper. Using that data, the Institute highlights what it characterizes as gaps between observed emissions and existing compliance frameworks, and calls attention to facilities it views as potential enforcement priorities. As companies continue to market their methane plume data, they will surely catch the attention of additional advocacy groups in search of ammunition for pressuring regulators into action.
Federal Uncertainty Could Spur Further State and Local Action
In contrast to the state regulators discussed previously, the federal government has provided less certainty on how it intends to regulate methane at landfills, which could spur further action from state regulators and advocacy groups.
EPA under the Biden administration began exploring whether advanced methane monitoring technologies—including satellite, aerial, and continuous monitoring tools—should play a larger role in landfill emissions regulation. But this never resulted in formal rulemaking, and recent Trump-era deregulatory moves in methane policy suggest that it may be left to state and local regulators to push for industry adoption of remote methane detection technologies.
An Attorney’s Perspective: Managing Risk in the Face of New Data
Landfill operators are moving into an environment where methane emissions can be observed externally, sometimes repeatedly, and potentially by parties other than the regulator. That reality changes how risk should be managed day-to-day.
#1: Operators Should Closely Track Emerging Regulations at the State and Federal Level
As California, Colorado, and Oregon demonstrate, methane rules are evolving quickly—and not always uniformly. What begins as a pilot program or site-specific requirement can quickly become a broader compliance expectation. Staying ahead of those developments allows operators to adjust practices before enforcement becomes an issue.
#2: Real Value in Engaging Proactively with Regulators
Remote detection technologies are still developing, and regulators are aware of their limitations—false positives, attribution challenges, and variability in plume interpretation. Operators who can credibly demonstrate good-faith compliance, robust monitoring, and prompt response protocols are better positioned to shape regulator expectations and avoid being treated as outliers when plume data surfaces.
#3: Operators should Actively Monitor for Potential Enforcement Triggers.
This includes those that originate outside traditional inspection channels. As discussed previously, satellite-based methane plume data is increasingly public and accessible. That means enforcement risk may arise not only from agency inspections, but also from third-party submissions, advocacy reports, or media attention. Early awareness of potential issues can allow operators to investigate and address conditions before they escalate.
#4: The Basics Still Matter
Maintaining well-functioning gas collection systems, cover integrity, and routine monitoring programs remain the most effective way to mitigate risk. Some of the emerging data on alleged “super-emitters” of methane suggest that large emissions events are often tied to identifiable operational issues. Preventing those issues—or addressing them quickly—remains the best defense against both regulatory and reputational exposure.
#5: Operators Should Consider How and When to Involve Counsel
Consider this particularly as remote detection data becomes part of the compliance landscape. Questions around internal investigations, data analysis, and response strategies may implicate privilege considerations, especially where third-party data is being evaluated alongside internal information. Thoughtful involvement of counsel can help ensure that sensitive analyses are appropriately protected where possible.
#6: Operators Should not Overlook the Broader Community and Government Relations Context
Methane emissions rarely exist in a vacuum. Issues such as traffic, truck queuing, dust, and odor can sensitize surrounding communities and amplify the impact of any perceived emissions problem. In that environment, even a single satellite-detected plume can become a focal point for broader concerns. Proactive communication, responsiveness to community complaints, and attention to overall operational impacts can help reduce the likelihood that methane issues escalate into enforcement or litigation.
As always, documentation matters. In a world where emissions may be independently observed, operators should ensure they are creating a clear, defensible record of monitoring, maintenance, investigation, and response. A well-documented record can be critical in demonstrating compliance, rebutting inaccurate interpretations of data, and positioning the facility effectively in the event of regulatory scrutiny or litigation. | WA
Michael Mims is an environmental lawyer at Liskow & Lewis APLC who helps waste industry clients and other industrial clients navigate environmental regulations. He is also an accomplished trial lawyer and is frequently called on by clients when environmental disputes result in litigation. Michael has litigated in Texas, Louisiana, Washington, D.C., and beyond. He can be reached at [email protected].
References
17 California Code of Regulations § 95469(b): ww2.arb.ca.gov/sites/default/files/barcu/regact/2025/LMR/app%20a-1.pdf
SB 726 (Oregon Legislative Assembly): https://olis.oregonlegislature.gov/liz/2025R1/Downloads/MeasureDocument/SB0726/Enrolled?
5 Code of Colorado Regulations 1001-35, Part E: www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=12387&fileName=5%20CCR%201001-35
Daniel H. Cusworth et al., “Quantifying Methane Emissions from United States Landfills,” Science 383, no. 6689 (Mar. 29, 2024): 1499–1504, https://doi.org/10.1126/science.adi7735
Matthieu Dogniaux et al., “Global Satellite Survey Reveals Uncertainty in Landfill Methane Emissions,” Nature 647, no. 8089 (Nov. 13, 2025): 397–402, https://doi.org/10.1038/s41586-025-09683-8
UCLA Emmett Institute on Climate Change & the Environment, “Spotlight on the Top 25 Methane Plumes in 2025: Landfills” (Apr. 20, 2026), https://law.ucla.edu/news/spotlight-top-25-methane-plumes-2025-landfills
California Air Resources Board, California Satellite Methane Project, ww2.arb.ca.gov/our-work/programs/california-satellite-methane-project (last visited May 4, 2026)
References
www.science.org/doi/10.1126/science.adi7735
www.nature.com/articles/s41586-025-09683-8
ww2.arb.ca.gov/our-work/programs/california-satellite-methane-project
ww2.arb.ca.gov/sites/default/files/barcu/regact/2025/LMR/app%20a-1.pdf
www.sos.state.co.us/CCR/GenerateRulePdf.do?ruleVersionId=12387&fileName=5%20CCR%201001-35
https://olis.oregonlegislature.gov/liz/2025R1/Downloads/MeasureDocument/SB0726/Enrolled?