Collecting food and yard waste might be necessary in order to avoid building costly landfill gas collection systems at the Alberni Valley Landfill, says a solid waste management consultant.
The B.C. environment ministry has limits as to how much methane gas a landfill can safely emit, and the Alberni-Clayoquot Regional District’s landfill is perilously close to hitting that limit, says Carey McIver of Carey McIver & Associates Ltd.
“The Ministry of Environment says that landfills that emit a certain amount of emissions have to put in a landfill gas collection system,” said McIver, who was hired by the ACRD to implement their 2007 Solid Waste Management Plan.
“McGill Engineering has looked at a very high preliminary, very high level cost estimate of about $5.5 million to construct the system,” she said.
The operating costs would be approximately $5.6 million for the 70-year lifespan of the system.
“So it could be that an organics diversion program, while it might be expensive, may not be as expensive as a landfill gas collection system. So you really need to compare the two.”
According to Al McGill of McGill Engineering, the ACRD is very close to needing to build the landfill gas collection system.
“We are so close that your fingernail is the thickness of the amount that we have,” said McGill.
“I’ve done some projections ahead but we could defer landfill gas by going into a wood waste ban at the Alberni landfill until about 2023.”
Collecting kitchen waste, McGill said, would have even more drastic results.
“If we divert organics, we could go to end of the current landfill life at the current rate of growth without any landfill gas collection system.”
According to an ACRD report, the maximum life span of the landfill will end in 2104. The ACRD will have to close the present landfill and find another location by then.
The cost of the landfill gas collection system will have to be balanced against that of building a compost processing facility.
According to a preliminary report from McIver, 5,780 tonnes of food waste and compostable paper were delivered to the Alberni Valley landfill in 2014. The majority of that (5,100 tonnes) was food waste.
However, the composting process requires a half-and-half split of carbon (food waste) and nitrogen (yard waste). Given the mere 341 tonnes of yard waste and 291 tonnes of land clearing waste delivered to the landfill in 2014, a source for more nitrogen producing waste will need to be found.
Cost estimates for a composting facility for the entire Alberni Valley are $2 million in capital costs and $450,000 annually in operational costs.
However, cost estimates for just the city of Port Alberni are much more modest. With a processing capability of only 1,500 tonnes annually, capital costs would be down to $600,000 and $150,000 annually for operation.
Citing the much lower costs, city of Port Alberni engineer Guy Cicon said that he believed that implementing a food and yard waste ban just within the city would be enough to extend landfill life.
“I suspect that even if we just took the amount from the city away, there would still be enough taken away from the landfill that we wouldn’t have to put in a landfill gas collection system,” said Cicon.
McGill stated that while he hadn’t crunched the precise numbers for that scenario, that was probably correct.
However, McIver pointed out that while economically isolating the city made sense, environmentally the regional district should all attempt to go to organics diversion.
“If you’re just worried about economics, then you can just do the city of Port Alberni. If we’re trying to have a big environmental impact and reduce emissions, then we should get it all out.”