Using a gas extraction and flaring system, the Benaraby Landfill's Carbon Abatement Project is just one example of Gladstone Regional Council's forward-thinking approach to responsible waste management.
Of all Council activities, Benaraby Landfill is the largest source of greenhouse gas emissions due to the methane released from the decomposition of buried waste. Landfill gas contains carbon dioxide and methane, which is a more harmful greenhouse gas.
Council has been proactively working towards reducing its greenhouse gas emissions and potential carbon liability since the introduction of the Carbon Pollution Reduction Scheme in 2008.
A carbon pricing assessment of Benaraby Landfill was undertaken to assist in calculating anticipated costs under the government's carbon price mechanism.
Efforts to reduce the effects of methane emissions will save millions of dollars by lowering Council's carbon tax liability.
In 2012, Council awarded a contract to Landfill Gas Industries Pty Ltd for the installation of a landfill gas collection, destruction and electricity generation system at Benaraby Landfill.
From 9 August 2012 to 29 January 2013 - 1,074,925 cubic metres of landfill gas were destroyed, with an average methane concentration of 54.88 per cent.
On 25 January 2013, the Clean Energy Regulator advised the 'Capture and Combustion of Landfill Gas from Benaraby Landfill Project' had been declared an eligible offsets project, an eligible Kyoto offsets project and first new abatement project registered in Australia.
Landfill cell development
In November 2012, Council started using its $1.9m landfill cell development, which will accept the region's (community, business and industrial) waste until 2018-19.
As part of the landfill cell development, 53,000 cubic metres of soil was removed to create 470,000 cubic metres of airspace capacity to service waste collection.
Cost savings were achieved by using clay extracted from earth works for a nearby stormwater/sediment dam to line the base of the new cell.
The landfill cell design incorporates environmental management features including a clay base, geo-synthetic clay liner, geo-membrane, protection layer, aggregate/rock leachate collection and drainage layer.
Overall, the Benaraby Landfill development enforces strong environmental management practices with an emphasis on minimising impacts on human health and responsible waste management incorporating innovative processes.
Design to such high standards minimises the potential of contaminants escaping from the site and into the environment.
Leachate (naturally created when water comes into contact with waste) is captured and reused to breakdown organic waste. A series of drainage pipes across the cell base transports collected leachate to a recovery sump to re-circulate into the waste mass via a series of vertical wells.
Gas extraction and flaring system
One of the most effective mechanisms to abate greenhouse gas emissions from landfills is destruction of methane by flaring collected landfill gas or combusting it in a generator to produce power.
Council commissioned a landfill gas extraction and flaring system at the site in August 2012, offering the ability for Council to halve its greenhouse gas emissions.
This will destroy about 95 tonnes of methane monthly, equivalent to abating around 2000 tonnes of carbon dioxide.
In addition, the system is due to start producing power and will also generate carbon credits to further help offset Council's carbon tax liability.
