Ahead of the landfill's potential closure in 2046, use of waste shredders is one way the Regional District of Nanaimo hopes to extend the life of the dump.
Chad Hermanson, RDN solid waste engineer technologist, gave a presentation on an updated regional landfill design operation and closure plan at the June 18 solid waste management committee meeting. He stated that waste-shredding vehicles are prolonging the site's life. The plan was last updated in 2009, and a primary objective this time around was maximizing 'air space' – the area available for municipal waste disposal, he said.
Based on the 2009 plan, there would have been approximately 1.25 million cubic metres of air space left at this time, Hermanson told the committee, but based on the update, utilizing current landfill practices using "horizontal and vertical limits of the property to increase the remaining air space," it has increased to 1.65 million cubic metres.
Staff will now focus on the most efficient use of air space by increasing density of processed waste. The RDN is currently on its fourth trial with an industrial waste shredder.
"The results of the most recent six-month rental [shredder] were encouraging from a density standpoint, however we did find that [it] struggled a little bit at times to keep up with the volume of waste that we receive on a daily basis," Hermanson said.
On average, density in the landfill's active cell was increased from 0.95 tonnes per cubic metre to 1.17 tonnes per cubic metre when waste was pre-shredded, a 23 per cent improvement in the six months.
The RDN is testing a larger machine with more horsepower, Hermanson said, allowing for faster processing of waste. In three weeks, officials have seen an increase in efficiency and the production of smaller material size, potentially further improving density.
The 2023 overall air space consumption indicated an apparent density of just over 1 tonne per cubic metre, the highest ever, with the five-year average at 0.91 tonnes per cubic metre, noted a staff report, an improvement of 11 per cent. The mark was reached with use of a shredder for three months and Hermanson said the RDN is curious about what a full year will bring.
The RDN enlisted engineering consultant WSP E&I Canada Ltd. to author the updated closure plan. It stated the last area for "permitted expansion" is in the site's southeast. It's estimated to have a footprint of approximately 2.8 hectares and development of the area will increase the landfill's total footprint to 25 hectares, the consultant's report said. The report also stated the RDN is looking at possibility of expanding outside the landfill boundary, but that would require B.C. Ministry of Environment approval.
The landfill has been in use since the 1930s.
The committee unanimously recommended the board accept the report for information.