The Garden Island landfill opens today (11 September) after almost 12 months of planning and preparation.
The landfill uses low calorific flare through Australian company Biogas Systems – the first time this technology is being employed in Australia.
The Garden Island Landfill Closure & Rehabilitation project has been a collaborative effort between the Western Region Waste Management Authority (WRWMA) and Renewal SA, with contractors Leed Engineering and Construction, and McMahon Services with Pacific Environment, and Tonkin Consulting as technical advisor, designer and Superintendent.
Previous investigations had demonstrated that landfill gas (LFG) is still in an active stage of generation at the site, and given the age and size of the site, landfill gas was expected to be produced beyond 2030.
The project team had monitored surface emissions and established that these did not require control due to performance of the deep soil cover system. Lateral emissions were found to need control at two locations due to historic construction practices at the site boundaries. These were needed to control emissions and to mitigate the potential human health and environmental risks at these discrete locations.
WRWMA and Renewal SA opted to solve these issues through the installation and management of a perimeter Gas Collection System (GCS) that would effectively extract and safely combust landfill gas using appropriate flaring technology. The Gas Collection System and flaring plant has been designed, installed and commissioned within approximately 12 months, and within the deadline of the end of August 2015.