Western University Researchers to Investigate Greenhouse Gas Emissions at City Landfill

The Western Institute for Earth and Space Exploration is leading a new project to measure methane released by London’s dump, with a multi-disciplinary team of researchers helping to track the potent greenhouse gas.

The team will use drones, satellites, as well as stationary and hand-held devices to determine exactly how much methane is produced at the city landfill on Manning Drive – officially named W12A – and whether any of it is escaping the collection system currently in place.

Federal funding of $200,000, announced this week, will help the team collect the crucial data over the next two years.

Head shot of Sarah Gallagher

Sarah Gallagher

“It’s very important we limit methane emissions as much as possible because it is a really potent greenhouse gas. Dumps make methane, that’s just a normal process of decomposing – it’s not like you can prevent that from happening,” said Sarah Gallagher, an astrophysicist and director of the Institute for Earth and Space Exploration.

“The ultimate goal is to provide information to the City of London and to the company that runs the methane collection system, so they can do the best job they can to capture all the methane and reduce emissions into the atmosphere.” – Sarah Gallagher, director of the Institute for Earth and Space Exploration

The team, which includes engineers, geographers, computer scientists and other experts, will use the information gathered using different methods to determine the best and most accurate way to measure and monitor methane emitted when Londoners’ trash rots at the dump:

  • Satellite imaging of the landfill will show methane emissions viewed from space, using equipment from GHGSat, a company that describes itself as a pioneer and global leader in “high-resolution remote-sensing of greenhouse gas from space.”
  • An autonomous drone equipped with an instrument to analyze gases will fly over the landfill to map methane concentrations at high resolution using a specialized detector called a tunable diode laser absorption spectrometer (TDLAS).
  • “Ground-based” detectors, some set at fixed locations around the landfill and others carried by a person essentially walking across the landfill.

Each approach has its own benefits and drawbacks, like the low-resolution of the satellite maps or the labour-intensive, difficult and smelly job of walking over the landfill holding the portable equipment.

The Western researchers will also monitor any changes in methane emissions across seasons or areas of the landfill to see what variables, if any, have an impact.

“Does it change by time of year, such as July in the heat of summer versus January in the depth of winter, covered with snow?” asked Jamie Skimming, the city’s manager of energy and climate change.

He’s eager to see the results to help with the city’s work managing greenhouse gases at the landfill.

“Tackling methane emissions from landfills will help clean our air and achieve the Government of Canada’s 2030 target to reduce overall greenhouse gas emissions by 40 to 45 per cent below 2005 levels. Successful demonstration of these technologies will provide Canadian landfill operators more tools to monitor landfill methane, identify leaks, and improve landfill gas recovery,” Minister of Environment and Climate Change Steven Guilbeault said of the funding.

Western’s project is among five receiving a combined $575,748 from the federal government’s fund for reducing methane emissions at landfills.

Right now, London doesn’t know exactly how much methane is produced by its dump. Estimates are based on mathematical modeling for emissions from decomposing organic matter – or trash – but may not be accurate.

This project will determine the real numbers.

“We estimate the methane emissions from our active and closed landfills is somewhere around five per cent of all of our locally generated greenhouse gas emissions. We’ve got a good handle on how much methane we’re capturing and flaring. But the other half of that equation is how much methane is being generated in the landfill overall,” Skimming said.

Methane flaring at London landfill

Methane produced by the W12A landfill in south London is collected and then burned off. (City of London photo)

It’s possible some methane is seeping out around the equipment that’s used to capture and collect it for burning. Skimming describes that system as similar to a series of giant straws, that penetrate the “lid” of each area of the landfill – a layer of soil and clay that sits on top of the garbage – and are used to pull out the gas generated.

Once or twice a year, the operator of the methane collection system checks for gaps through which gas could be escaping, but tracking emissions using the three technologies Western plans to deploy will give much more frequent and accurate results.

Partnering with Western is a key part of the municipality’s climate emergency action plan and its goal to “advance knowledge, research and innovation,” Skimming said.

“The beauty of this project is the researchers at Western are going to be doing all the hard work to test the satellite and drone measurements and how all that tech works,” Skimming said, calling it an “really interesting” endeavour that staff will highlight to city council.

The approach to the landfill measurements is innovative not just because of the new equipment being deployed and compared, but because of the people driving the work.

“We have the expertise in hand – these are all experts who are already present at Western – but we’re coming together to work on this problem that’s really important,” Gallagher said.

“The idea is to develop the methodology to allow us to answer these questions – how much methane is being emitted by the city of London landfills? Where and when is it emitted? – so they can go after the largest sources and develop methods for dealing with it.”

 

MEET THE TEAM

Western researchers:

Chemical and Biochemical Engineering: Franco Berruti, ground-based instruments

Computer Science: Anwar Haque, drone

Electrical and Computer Engineering: Jayshri Sabarinathan, drone-based TDLAS

Geography and Environment: James Voogt and Jinfei Wang, data integration and mapping

Institute for Earth and Space Exploration: Sarah Gallagher, team lead and Eric Pilles, project management

Mechanical and Materials Engineering: Eric Savory and Kyle Graat, ground-based instruments

Partners:

City of London: Jamie Skimming

GHGSat: Eric Choi

Comcor Environmental: Denise Burgess