FEATURED TOPIC – LANDFILL MANAGEMENT
The Shoal Bay Leachate Treatment Plant is believed to be the first global permanent facility treating PFAS in leachate, coupled with biological and ecological treatment and zero disposal.
Natural selection
CITY OF DARWIN IS HOME TO A WORLD FIRST LEACHATE TREATMENT THAT COMBINES ENGINEERING AND NATURE-BASED SOLUTIONS.
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wenty years ago, it might have been okay to divert leachate to a pond and hope that it evaporated away. Today, leachate management requires more thought, says David Leinster. The Wastewater and Solutions Development Manager for The Water & Carbon Group, David, says leachate is an ongoing problem that needs a continuous, sustainable solution. The Water & Carbon Group has commissioned a global first per- and polyfluoroalkyl substances (PFAS) and leachate treatment plant for the City of Darwin at Shoal Bay that combines 32 / WMR / October 2023
engineered and ecological solutions. David says while the combination is not new, it’s underrepresented in the industry. In the case of Shoal Bay, the combination is suitable to convert the leachate into a usable water source. The plant uses the Water & Carbon Group’s patented LEEF (Low Energy Evaporative Fractionation) System to remove PFAS from the leachate. Treated effluent from the LEEF system is moved through biological treatment stages, including a wetland. From there, the leachate is used to irrigate a capped landfill planted
with Vetiver grass that is salt tolerant and can uptake residual nitrogen and metals from the water. “A lot of leachate treatment technology produces other waste streams that need to be disposed,” David says. “The Shoal Bay plant was designed to create as little waste as possible. “While the water application is not a high flow, it adds value because it’s producing a Vetiver crop and the organic matter produced will have some value.” As a by-product of waste and rainfall capture, leachate contains