Scientists have discussed the possibility of deploying drones to detect methane gas emissions – a major source of global warming – for well over two years.  A seminal study published by the American Chemical Society in 2021 found that sensor-equipped aerial drones would likely be a “valuable complement” to ground-based detection systems.  Since 2019, a growing number of U.S. states and localities have acquired drones for site-specific methane gas detection, usually at local landfills.  Currently, drone-based systems are operational in 28 states and at more than 150 landfills. To date, some16,500 methane leak sources have been identified and at least partially remediated.

The demonstrated success of these efforts has finally prompted federal action.  Last January, the EPA approved the use of the first drone funded by a federal agency to monitor emissions at municipal waste sites.  The company chosen for the work, Ann Arbor, MI-based Sniffer Robotics, deploys an unmanned aircraft – dubbed SnifferDRONE – that collects air samples directly at the ground surface and correlates its measurements of methane emissions to latitude and longitude coordinates recorded during flight.  This “hyper-local” solution, as the company calls it, allows authorities to zero in on the source of the leak and to target remediation efforts with precision, reducing wasteful field resources.  The drone can cover multiple potential leak sites in a fraction of the time it would take ground surveyors.

Another key advantage is improved workplace safety.  In an average landfill, a ground surveyor may end up walking about 15 miles and become exposed to a wide array of hazards, from extreme temperatures to steep and uneven terrain and dense vegetation. Surveyors may also encounter dangerous animals, including snakes, rats, wild dogs and even alligators as well as ticks and scorpions. There’s also the ever-present threat of exposure to landfill gasses and other toxic waste that can leave them permanently injured.

Governments aren’t the only entities concerned about methane emissions. Another company, DroneDeploy, is assisting oil and gas concerns to perform their own methane gas emission surveys to comply with new and stricter guidelines from the APA.  Companies in this sector face both “intentional” emissions, which are unavoidable, and about 25% of the total, as well as “fugitive” emissions, the remaining 75%, which can be controlled.  As with landfill inspections, walking these facilities is labor-intensive, costly and potentially dangerous, while drones equipped with thermal cameras can use heat sensors and advanced data analytics to detect and verify a leak and then send out a field team to close it without having to walk the entire site.  Drones can also map an entire facility repeatedly and store and process the visual data and GPS coordinates to detect and model leak patterns over time at the touch of a finger.  With drones it is possible to anticipate problems in the facility – and not just methane leaks but also stress fractures, corrosion, and other issues – long before they become more serious problems.

Drones are allowing public and private entities the tools to reduce the largest source of carbon pollution in the world – an estimated 30% of all toxic emissions (far higher than carbon dioxide). But if methane emissions are getting easier to detect, controlling them is still a huge challenge.  Even energy companies that have begun developing systems to reduce their methane emissions aren’t able to measure their full magnitude, in part because they are measuring leaks for only a fraction of their operations.  Most experts say the actual degree of emissions is twice to three times the emissions estimates the companies currently produce.

The solution?  Expand the aerial surveys and make them mandatory.  Satellites and manned aircraft are also playing a key role in methane detection but drones offer a more precise site-specific means of performing the same work at a lower cost and with a smaller footprint.  The EPA’s pilot drone program with Sniffer Robotics will help spread awareness and could lead to tough new standards – but it’s only a start.  Time is running out.