Arie Feltman-Frank

Remote Sensing as a Supplement to Emissions Monitoring and Quantification

Feltman-Frank  By:  Arie Feltman-Frank

GHGSat CO2 sensor

According to a recent Bloomberg article, a company did not report an August 2023 air emissions event to state environmental regulators until December, just days after the company was asked by Bloomberg Green about a methane plume detected in August over one of its compressor stations.

The methane plume was observed via a remote sensing instrument onboard the International Space Station (“ISS”) and publicized in November 2023 by Carbon Mapper, a California non-profit that is planning to launch satellites that it states will persistently (i.e., on a daily to weekly basis) pinpoint, track, and make available to the public methane and carbon dioxide emissions at individual facilities located within “high-priority areas.”

The launch of the first Carbon Mapper Coalition satellites is expected in 2024. These satellites will join other recently launched or soon-to-be launched satellites with sensors that can detect methane and carbon dioxide emissions (e.g., GHGSat, MethaneSat). Notably, GHGSat describes its sensor, Vanguard, launched into orbit on November 10, 2023, as the first orbital sensor able to pinpoint carbon dioxide emissions from individual industrial facilities.  

With Carbon Mapper’s satellites not yet launched, the organization’s online data portal includes data from airborne surveys, as well as global observations by NASA’s Earth Surface Mineral Dust Source Investigation (“EMIT”) instrument onboard the ISS (which is the instrument that observed the methane plume over the compressor station).

What’s New?

Pollution monitoring by satellite is not new. What is new is the fact that remote sensing technologies are advancing in their ability to continuously monitor, detect, and quantify emissions and attribute the emissions to individual sources. Moreover, satellite data is becoming increasingly accessible to enforcement agencies and the public. As a result, we are seeing an increased effort by governments, non-profit organizations, and industry to harness remote sensing technologies to better understand and reduce pollution.

The incident highlighted above is but one example of what happens when satellite-derived data goes public, allowing a third party to discover an emissions event—in some cases, before the source. This type of incident is not necessarily rare.

For example, the possibility of third-party detection is incorporated into EPA’s final rule setting new source performance standards and emissions guidelines for oil and natural gas facilities under the Clean Air Act (the “Methane Rule”). Under this rule, EPA-certified third parties will be able to use EPA-approved remote sensing technologies to notify the Agency of “super-emitter events” (100 kg/hr of methane or greater), ultimately requiring owners and operators to investigate the events and, if necessary, take corrective actions.

Legal Risks

The availability of advanced satellite-derived emissions data can lead to legal risks that can materialize in enforcement actions (which are likely to become more common, particularly with respect to methane emissions at oil and natural gas operations and landfills), as well as citizen suits and tort actions. Third-party detection can also make it harder to favorably resolve violations pursuant to enforcement policies that favor voluntary self-disclosure. Finally, third-party detection is not good for a company’s reputation and can lead to increased public scrutiny.   

Importantly, these legal risks are not limited to oil and natural gas production operations and landfills (though methane emissions from these sources are certainty a primary focus so far). Nor are these legal risks limited to methane and carbon dioxide emissions. For example, Tropospheric Emissions: Monitoring of Pollution (“TEMPO”), an instrument that was launched into space in August 2023, measures pollutants including nitrogen dioxide, ozone, aerosols, and sulfur dioxide on an hourly basis during the daytime over North America at neighborhood scales.

Preparing for What’s to Come

Companies and investors associated with emissions-intensive operations should do the following to prepare for what’s to come.

  • Familiarize yourself with what remote sensing technologies are out there (or may be soon) that can detect emissions, as well as the extent to which the detected emissions can be attributed to the relevant operations and reliably quantified. Also, consider whether the emissions data will be available to the public.
  • If necessary, conduct a tailored analysis of the legal risks that remote sensing technologies pose to your current and future operations and consider the admissibility of satellite data in administrative and civil proceedings.
  • Consider whether it is worth utilizing remote sensing technologies to supplement current pollution monitoring and quantification efforts (e.g., to comply with monitoring requirements, as well as future climate reporting requirements). Indeed, under EPA’s Methane Rule, referenced above, owners and operators of oil and natural gas facilities will be able to use advanced methane detection technologies as an alternative to ground-based methods to comply with monitoring requirements. With respect to climate reporting, remote sensing technologies may be especially helpful for companies seeking to better understand emissions that are outside of their direct control.

Also, note that remote sensing technologies may make their way into settlements. For example, on December 12, 2023, the owner of a municipal sanitary landfill agreed to spend approximately $30,000 to use drone technology to monitor methane emissions to resolve alleged violations of the Clean Air Act. This was the first settlement involving the use of drones for surface emissions monitoring.

We will continue to track remote sensing technologies on the Corporate Environmental Lawyer. Please do not hesitate to reach out if you have questions.