An innovative phytocapping trial has shown positive results at a local landfill, not only minimising the generation of leachate but creating habitat for wildlife.
Bundaberg Regional Council has implemented sustainable capping technology which, over time, is set to transform the landfill landscapes of the region.
Known as a phytocap, this pioneering technology uses scientific modelling to select a combination of native plants and soils which act as an efficient bio-pump system.
This controls the amount of rainfall that can access the compacted waste, reducing the percolation of water and protecting local groundwater supply.
The Qunaba Waste Management facility’s phytocapping trial began two years ago and after showing positive results, planning for stage two is underway.
Senior Environmental Technical Officer Victoria McKay initiated the trial and said the site looked vastly different after two years of growth.
“Our sensors are showing the tree and grass species which survived the earlier drought are now able to extract moisture from the soil profile down to 1.5 metres below the surface,” she said.
“This has effectively reduced drainage into the waste mass and minimised the generation of leachate.”
Victoria said she was pleased to see the trial site had also created a habitat that attracted more wildlife.
Trial cameras have captured a burrowing bandicoot at night and a local pheasant coucal investigating the bandicoot burrows, possibly for nesting.
“Burrowing bandicoots increase the organic carbon content and aeration of the soil, in turn improving soil quality and supporting healthy root growth,” she said.
“A busy bandicoot can move upward of 13kg of soil a night, burying the dry fuel load of dead grasses and leaf litter on the surface as they forage and burrow.
“This also helps to reduce the risk of fires. “
Phytocapping trial moves ahead
The design for the next stage of the project is complete and will increase the trial area to around 2.6 ha toward the northern end of the landfill along Grange Road.
An onsite nursery is under construction to raise the 3200 native trees for the next stage.
Soils and mulch are being stockpiled to begin a staged construction program for the additional trial site which will begin around October 2023.
While new mulch stock won’t be available to the public this round, the material is a vital resource for the trial, helping the soil to retain moisture and native trees to get established.
Methane emissions will be monitored from the stage two trial area to ensure the greenhouse gas emission profile is managed effectively with the new cap design.
Council's waste and recycling portfolio spokesperson Cr Tanya McLoughlin said the innovative phytocapping trial was a whole-of-council initiative.
She said the Parks and Land Protection teams provided their skillset in the design of the nursery while the GIS and Survey teams had been tracking the progress of the canopy coverage using drone technology and mapping software.
“Through some fantastic team work, the results of this two-year trial have shown how phytocapping can sustainably manage our landfill sites while boosting the environment,” Cr McLoughlin said.
“Congratulations to those involved.”