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Biogas Systems Australia


Garden Island Landfill Project

October 29, 2018

LFG Remediation and Lo-Cal Flare Supply


The Garden Island landfill remediation project was undertaken to mitigate fugitive gas emissions from the site in order to protect surrounding sensitive receptors and comply with surface gas emission standards. Biogas Systems were engaged to design, construct and operate a staged gas mitigation system in order to meet regulatory compliance, allowing for carbon credits to be generated under the ERF.


The first stage involved undertaking a pumping trial in order to assess the
effectiveness of an active system and prove the novel and award winning
pin well design. The pin well system involved the installation of 6 m deep pin wells by modified earth moving plant. A pin well maker was adapted to an existing excavator mounted hydraulic hammer. The pin well maker was simple in design but highly effective in creating pin wells in a very short period of time, making the overall process cost effective.


The project also involved undertaking cap rectification works, and installation of a thick compost layer to facilitate biological methane oxidation. An ‘Ecoblanket’ was applied to the recently reinstated steep clay embankment using an express blower system. The Ecoblanket has the combined effect of providing a medium for vegetation establishment, which limits wind and water erosion in the steep areas, but also provides a medium to allow microbes to function and oxidise methane. The total area reinstated and covered with the Ecoblanket was over 3,000 square meters, and was highly successful in meeting compliance criteria for fugitive emissions.


The end flare design was based on a 250 m3/hr Lo-Cal HT flare, which has demonstrated to combust LFG with a methane concentration of 12 %v/v whilst maintaining combustion temperatures of 1,0000C. This is understood to be the first true Lo-Cal flare operational in Australia capable of continuous operation without a requirement for supplemental LPG.


Biogas Systems continues to undertake monthly monitoring and maintenance of the system, which has been a great success and meets the regulatory objectives.