Garden Island Landfill Gas Management

Garden Island Landfill Gas Management is a landfill gas project located at Garden Island, approximately 16 kilometers northwest of the Adelaide CBD in South Australia. It was registered in August 2015 and covers approximately 52 hectares.

Landfill gas methodology projects involve installing gas collection systems to capture methane generated by the decomposition of organic waste in landfills. Instead of venting into the atmosphere, the collected methane is combusted through flaring or used for electricity generation, effectively converting it into carbon dioxide, which has a significantly lower global warming potential.

Garden Island is a reclaimed area situated within the Port River estuary, characterized by a coastal and industrial landscape. The region experiences a Mediterranean climate with hot, dry summers and cool, wet winters. As a closed landfill site in a sensitive estuarine zone, the typical "soil" consists of a clay and soil cap installed over legacy waste, bordered by estuarine mud, mangroves, and marine waterways.

This project recommenced operations of a dormant gas collection system on a landfill that closed in 2001, focusing on managing legacy waste. Because the aging legacy waste produces landfill gas with unusually low methane concentrations (down to 12%), standard flares were ineffective and prone to repeated shutdowns. To overcome this challenge, the project utilizes specialized "Lo-Cal" (low calorific) flaring technology capable of autonomously and safely combusting low-concentration methane at over 1,000 degrees Celsius. This was a collaborative project by the Urban Renewal Authority (trading as Renewal SA) designed to mitigate lateral fugitive emissions and protect both nearby residents and the surrounding marine environment.