“There’s very harmful landfill gas that is able to escape through the top of it. We need to cap it, we need to put three feet of clay on top of it."
Author of the article: Lauren Boothby
Publishing date: Nov 25, 2022 •
Heavy equipment is used to moved garbage at the Clover Bar landfill when it was still operating in 2005. Postmedia, file
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Edmonton’s Clover Bar landfill is still uncovered and releasing fumes more than a decade after closing to the public, and new capture technology is in the works to convert its methane into renewable biogas for sale.
City council’s utility committee met privately Friday to get an update on the landfill-gas-to-renewable-gas conversion project at the Clover Bar landfill. The project was approved in February 2021, also in private, and is expected to be complete by mid-2024.
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Edmonton’s Clover Bar landfill is still uncovered and releasing fumes more than a decade after closing to the public, and new capture technology is in the works to convert its methane into renewable biogas for sale.
City council’s utility committee met privately Friday to get an update on the landfill-gas-to-renewable-gas conversion project at the Clover Bar landfill. The project was approved in February 2021, also in private, and is expected to be complete by mid-2024.
What was discussed at Friday’s meeting isn’t known, but Edmonton waste services’ utility rate filing offers some details about remediating the landfill, the new renewable natural gas facility, and funding. The waste services branch plans to spend $9.7 million next year and $3.3 million in 2024, along with a $10-million provincial grant, the city confirmed. Some cash will come from the waste services liability fund collected over the years. $1 million has been spent to date.
Capital Power is paying for a portion of the costs and will co-own the site, sharing the profits with the city, although the city would not confirm the contribution or payout.
Capital Power already runs a collection system converting landfill gas into electricity but it is aging and captured less than half of the emissions as of 2018, according to a previous utility rate filing.
Capping landfill would have big impact on greenhouse gas emissions
Before the meeting, waste services branch manager Denis Jubinville told the utility committee that covering the landfill is likely the biggest impact waste services can have on reducing greenhouse gases in the region. This work will be done alongside creating the conversion system.
“There’s very harmful landfill gas that is able to escape through the top of it. We need to cap it, we need to put three feet of clay on top of it,” he told councillors. “That will be a significant reduction in greenhouse gas.”
In an interview, Jubinville couldn’t say why the site hasn’t been covered since 2009 — he only took over leadership about a year-and-a-half ago — but said it takes a long time.
However, doing so is a priority for Jubinville, especially because the old landfill is full of organic waste.
“When (organics) decompose they create gas, and that’s really, really bad greenhouse gas. That’s methane, and that’s really bad for the environment, and because we don’t have a really thick layer of dirt on top, it’s going into our atmosphere right now,” Jubinville told Postmedia. “We really need to cap it.”
The city did not confirm the expected emissions reduction by deadline. However, according to the 2021 utility rate filing, the renewable natural gas technology could reduce carbon dioxide emissions by 149,500 tonnes per year, and more than 2.5 million tonnes by 2040.
Postmedia files show the original plan for Clover Bar landfill was to cover it fully with native vegetation and link the site to trails in the river valley
Former waste management spokesman Gary Spotowski told the Edmonton Journal in 2009 that Clover Bar would continue releasing gas for 40 to 50 years, but it wasn’t a danger to the public.
At the time, Spotowski said “improved compaction” at the landfill meant when it’s fully covered it won’t create several small hills such as those in Rundle Park — which used to be the Beverly dump
Converting landfill gas to renewable natural gas, and putting it into the distribution network for sale, will be a first-of-its kind project in Alberta.
According to the capital profile in the 2023-2024 rate filing, the waste services branch chose a technology called pressure swing absorption because it is proven and reliable, conserving up to 98 per cent of the methane drawn out during the process.
Once collected, landfill gas is sent into a system to remove impurities like water, siloxane, ammonia, carbon dioxide, and hydrogen sulfide. This conditioned gas is fed into what’s called a pressure swing absorption upgrading unit that has a series of vertical towers connected by a complex network of valves and switches, cycling the gas between low pressure and high pressure where chemicals like carbon dioxide are absorbed, while others are captured in a filter.
This system is expected to generate up to 245,000 GJ per year for at least 20 years and bring in $3 million of revenue annually. The 2021 version of the capital profile said it would capture more than 75 per cent of the currently generated gas.
‘Pressure cooker’
While Jubinville thinks covering the landfill is important, it’s a complicated and long process. As they age, landfills can become unstable, he said.
“When you cap it, you’re creating a pressure cooker. It is still decomposing, and it’s creating pressure inside of this landfill, so we need a system to relieve that pressure.”
If the cover is too heavy, the sides could be pushed out and spill into the North Saskatchewan River. Reinforcing the riverbank is another part of the plan to prevent this from happening.
The methane created can be released, burned, or used for another purpose — in this case, drilling wells into the mound to pull out liquid and gas to be converted to renewable natural gas.
“If we can use this gas in an effective way in converting it into renewable natural gas, it is to the benefit of our community,” Jubinville said.
The Clover Bar landfill opened in 1975, closed in August 2009, and was Edmonton’s first engineered sanitary landfill. It lasted 20 years longer than expected after recycling programs were introduced in the late 1980s. The secondary landfill, which was built after the 1987 tornado, ceased operations in 2008
Capital Power is paying for a portion of the costs and will co-own the site, sharing the profits with the city, although the city would not confirm the contribution or payout.
Capital Power already runs a collection system converting landfill gas into electricity but it is aging and captured less than half of the emissions as of 2018, according to a previous utility rate filing.
Capping landfill would have big impact on greenhouse gas emissions
Before the meeting, waste services branch manager Denis Jubinville told the utility committee that covering the landfill is likely the biggest impact waste services can have on reducing greenhouse gases in the region. This work will be done alongside creating the conversion system.
“There’s very harmful landfill gas that is able to escape through the top of it. We need to cap it, we need to put three feet of clay on top of it,” he told councillors. “That will be a significant reduction in greenhouse gas.”
In an interview, Jubinville couldn’t say why the site hasn’t been covered since 2009 — he only took over leadership about a year-and-a-half ago — but said it takes a long time.
However, doing so is a priority for Jubinville, especially because the old landfill is full of organic waste.
“When (organics) decompose they create gas, and that’s really, really bad greenhouse gas. That’s methane, and that’s really bad for the environment, and because we don’t have a really thick layer of dirt on top, it’s going into our atmosphere right now,” Jubinville told Postmedia. “We really need to cap it.”
The city did not confirm the expected emissions reduction by deadline. However, according to the 2021 utility rate filing, the renewable natural gas technology could reduce carbon dioxide emissions by 149,500 tonnes per year, and more than 2.5 million tonnes by 2040.
Postmedia files show the original plan for Clover Bar landfill was to cover it fully with native vegetation and link the site to trails in the river valley
Former waste management spokesman Gary Spotowski told the Edmonton Journal in 2009 that Clover Bar would continue releasing gas for 40 to 50 years, but it wasn’t a danger to the public.
At the time, Spotowski said “improved compaction” at the landfill meant when it’s fully covered it won’t create several small hills such as those in Rundle Park — which used to be the Beverly dump
Converting landfill gas to renewable natural gas, and putting it into the distribution network for sale, will be a first-of-its kind project in Alberta.
According to the capital profile in the 2023-2024 rate filing, the waste services branch chose a technology called pressure swing absorption because it is proven and reliable, conserving up to 98 per cent of the methane drawn out during the process.
Once collected, landfill gas is sent into a system to remove impurities like water, siloxane, ammonia, carbon dioxide, and hydrogen sulfide. This conditioned gas is fed into what’s called a pressure swing absorption upgrading unit that has a series of vertical towers connected by a complex network of valves and switches, cycling the gas between low pressure and high pressure where chemicals like carbon dioxide are absorbed, while others are captured in a filter.
This system is expected to generate up to 245,000 GJ per year for at least 20 years and bring in $3 million of revenue annually. The 2021 version of the capital profile said it would capture more than 75 per cent of the currently generated gas.
‘Pressure cooker’
While Jubinville thinks covering the landfill is important, it’s a complicated and long process. As they age, landfills can become unstable, he said.
“When you cap it, you’re creating a pressure cooker. It is still decomposing, and it’s creating pressure inside of this landfill, so we need a system to relieve that pressure.”
If the cover is too heavy, the sides could be pushed out and spill into the North Saskatchewan River. Reinforcing the riverbank is another part of the plan to prevent this from happening.
The methane created can be released, burned, or used for another purpose — in this case, drilling wells into the mound to pull out liquid and gas to be converted to renewable natural gas.
“If we can use this gas in an effective way in converting it into renewable natural gas, it is to the benefit of our community,” Jubinville said.
The Clover Bar landfill opened in 1975, closed in August 2009, and was Edmonton’s first engineered sanitary landfill. It lasted 20 years longer than expected after recycling programs were introduced in the late 1980s. The secondary landfill, which was built after the 1987 tornado, ceased operations in 2008
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