Greenhouse Gas Reduction
RDN Landfill Gas Reduction and Utilization
Landfill gas (LFG) is produced when microbes decompose garbage in a landfill, most of which occurs anaerobically or in the absence of oxygen. This process generates roughly equal amounts of methane and carbon dioxide. Methane is a powerful greenhouse gas, with a global warming effect 21 times greater than carbon dioxide.
The RDN has introduced several innovative technologies to collect, monitor, reduce and eventually utilize LFG emissions at the Regional Landfill through its LFG Management Plan. This has resulted in reducing annual greenhouse emissions from the landfill by roughly 21,606 tonnes of carbon dioxide equivalent.
Landfill Gas Collection System
|Landfill gas collection piping.|
In 2002, the RDN received a $500,000 grant from the Green Municipal Investment Fund to expand the Regional Landfill’s LFG collection system and increase LFG recovery by 65 per cent.
The LFG gas collection field consists of 30 vertical extraction wells, two horizontal extraction trenches and a network of collection piping. A centrifugal blower creates a vacuum to extract the LFG from the collection field.
Landfill Gas Monitoring
|Soil gas sampling.|
An on-site monitoring program monitors and analyzes landfill gas at the Regional Landfill in accordance with BC Ministry of Environment guidelines and WorkSafe BC requirements.
The LFG monitoring program determines the volumes of LFG collected and destroyed. Sampling and monitoring is critical to maintaining the effectiveness of the LFG collection and treatment system.
Landfill Gas Utilization
|Landfill gas flaring station.|
Methane collected at the Regional Landfill is currently burned at an on-site flare station to reduce greenhouse gas emissions and other impacts such as nuisance odours. The RDN has entered into an agreement with Cedar Road LFG Inc., which is constructing a facility at the Regional Landfill that will use methane collected to produce electricity.
The electricity generated at the Regional Landfill will be fed into the BC Hydro power grid. It’s anticipated that plant operated by Cedar Road LFG Inc. will produce 1.5 megawatts of green power, sufficient to supply 1,200 homes.
|Landfill capping program construction.|
The RDN has constructed an interim cap along the Regional Landfill’s east slope. Completion of the cap in the area no longer receiving waste generates several environmental benefits by reducing greenhouse gas emission and leachate caused when water filters through garbage.
The landfill capping project used a multi-layer system to contain landfill gases, improving LFG utilization and reducing pollution. By acting as a lid, the cap reduces oxygen intake, contains landfill gases, and minimizes water infiltration. An organic biocap, one of the first of its kind to be installed at a BC landfill, promotes the growth of methane-consuming bacteria for methane that infiltrates the cap. Field studies are being conducted to evaluate the effectiveness of landfill capping project in containing subsurface methane and reducing ambient methane emissions.
|Landfill equipment is now powered by biodiesel.|
Diesel-powered equipment at the Regional Landfill and Church Road Transfer Station has now been switched to an ultra-low sulfur biodiesel fuel blend, reducing both tailpipe and greenhouse gas emissions. Nanaimo Regional Transit is supplying the biodiesel fuel blend to the RDN Solid Waste Facilities through its participation in BC Transit’s biodiesel program.
No modifications to the diesel-powered compactors, loaders, backhoe, and mower in use the Regional Landfill and Church Road Transfer Station. The equipment consumed 155,418 litres of diesel fuel in 2006 and the cost of using biodiesel will be the same or less than regular diesel fuel.