Downer EDI : Delivering solutions to Tasmania’s waste management challenge

06/10/2022

Downer General Manager Tasmania, Marcus Stephens, said the works involved construction of the final landfill cell that would be built at the Glenorchy site.

"We know that councils across Australia are faced with a significant challenge in managing waste generated in their communities. As landfill sites reach their capacity limits, communities need to look to alternative solutions for waste management," Mr Stephens said.

"Extending the life of the Jackson Street landfill site gives the Glenorchy City Council time to plan for sustainable waste management beyond the useful life of the facility."

Building a landfill cell is done in steps and significant preparation is needed to make sure the cell is robust and complies with the requirements of the Environment Protection Authority.

"The project presented technical challenges in terms of managing the interface between the existing unlined landfill and new landfill cell, and associated management of stormwater and leachate," Mr Stephens said.

"One of the most important things is to ensure that contaminated water from domestic waste can't find its way into the water table. To make sure it doesn't, there are many layers put in place in the bed of the cell before it becomes operational."

The base of the landfill cell is lined with certified clay, which is then compacted. On top of that sits a woven clay infused liner (X1000 GCL) product that swells when moisture gets into it, creating an additional seal. There's an engineered plastic liner (HDPE) on top of that, a cushioning layer (A84 Bidim) to protect the plastic, and finally a layer of drainage rock which contains a drainage system to capture any contaminated water generated by the waste within the cell and directs it away safely.

"Downer is actively delivering sustainability benefits to communities in Tasmania, not just through enabling waste management, but also through our road surfacing material ReconophaltTM which uses waste materials such as soft plastics, glass and toner that would otherwise be bound for landfill or stockpiled," Mr Stephens said.

"In producing ReconophaltTM we are helping communities turn their waste products into value-added material and avoiding use of virgin materials. Importantly, waste materials are diverted from landfill, extending the useful life of facilities like the one at Jackson Street in Glenorchy."