Ten years after the B.C. government ordered Campbell Mountain Landfill and others like it to install gas-capture systems, there appears to be a safer, more cost-effective way to do it, and it was developed right here in Penticton.
Later this spring, the Regional District of Okanagan-Similkameen will submit to the Ministry of Environment an application seeking permission to use biocover – composed of sand, wood chips and biosolids from wastewater treatment plants – to cut down on how much methane gas escapes from organic waste as it decomposes at the Campbell Mountain Landfill.
Specialized bacteria in the biocover feed on methane, which is a greenhouse gas, and break it down into water and carbon dioxide.
However, the only way larger landfills are currently permitted under provincial regulations to capture methane is to use a series of wells and pipes to collect the gas, which can then be used to produce energy.
But that method isn’t suitable for Campbell Mountain Landfill, because it poses a fire risk, according to RDOS engineering manager Liisa Bloomfield.
“We’re a very arid climate and underneath the landfill it’s all fractured bedrock. So if you put in something that sucks out air, you’re eventually going to get air coming up from underneath and you’re going to have a fire,” Bloomfield told the board at its March 19 meeting.
“So we were really concerned about that, which is why we pursued the biocover.”
Pursuing biocover meant proving to the B.C. government that biocover can be as good – or better – than a standard gas-capture system.
To do that, the RDOS worked with consultant Sperling Hanson Associates to set up a test site at Campbell Mountain, where an experiment using different formulations of biocover ran from April 2017 to May 2018.
The results, which were compiled in a final report in August 2019, showed the biocover soaked up an average of 77% to 83% of the methane produced below it – more than enough to meet provincial requirements.
Bloomfield noted the biocover does not give off a noxious odour – “it smells like dirt” –and is relatively cheap.
According to her calculations, setting up biocover will come with a $1.4-million price tag and carry operating costs of $12 million over the life of the landfill. That compares to $4.8 million for setup, and $25 million for operation, of a regular gas-capture system.
The drawback to biocover is the methane can’t be put to use, but RDOS chairwoman Karla Kozakevich said the amount of gas produced at Campbell Mountain – about 1,200 tonnes per year – isn’t enough to make generating power cost-effective anyway.
Kozakevich said the Ministry of Environment has been supportive of the RDOS’s efforts and “seems really positive about the results.”
The next step in the process is a 30-day public consultation period during which people can comment on the application to vary provincial regulations, after which the application can finally be submitted.
“It would be a monkey to get off our backs, for sure,” said Kozakevich.
“I’m extremely proud of the engineering team at the RSDOS, along with our consultants Sperling Hanson Associates, for coming up with an innovative solution.”