Saltwater Creek landfill capacity expanded
19 September 2019
The Saltwater Creek landfill will be able to hold an extra 260,000 tonnes of rubbish following the completion of work on a new one-hectare cell.
Cr Anne Maddern said the project took a little more than four months to complete.
“When the cell is full, it will form a small hill 14 metres high, level with the cells beside it,” she said.
“We estimate that at the current rate waste is collected, it will take two years to fill the cell, but its life could be extended if we all recycled and reuse more.”
Cr Maddern said almost 175,000 tonnes of waste was brought to the site last year, but only 70,000 tonnes went into landfill. The rest was recycled.
“Council has made improvements to the layout of the site to help us store waste so it can be sorted and we’re embarking on an education program to encourage residents to sort their load before they reach a transfer station or landfill site,” she said.
“The more people sort their load, the easier it will be to recover and recycle, the faster they will dispose of their waste onsite and the less they will have to pay.
“While people know they can sort out for recycling e-waste, steel, timber and green waste they can also sort out concrete and clean fill.
“The concrete is crushed and the rock reused as fill and the steel recycled.
“Builders also should sort their waste. Rather than dumping everything into one skip, they can cut costs by sorting out steel, copper, wood, roof tiles, bricks and concrete at the building site, while Council has set up new storage areas to accept builders waste.”
Building the cell requires good planning, as the work has to be finished just in time it is needed.
“We cannot build the cell too far ahead of time as it could fill with rain water before we start using it,” Cr Maddern said.
To make the new cell, which follows the latest design standards to protect the environment, a hole was dug six metres into the clay base of the site.
Work then started on layering a clay and rubble base to stop rainwater and liquid waste oozing out of the waste leaching into the environment.
The 1.4 metre think base is made of layers which consist of an 300mm of compacted clay covered by, engineered liner, 300 mm of crushed concrete, 300 mm of drainage rock and finally 500 mm of mulch is spread on top.
The liquid is collected and recirculated back into the site. The treated water is then pumped to the Aubinville Waste Water Treatment Plant for further treatment.
Before the cell is full, Council will start work on the next cell, the ninth on the site.
“Our investigations indicate that the site has approximately seven years of working life left,” Cr Maddern said.
“We will then be left with a small mound about 20 metres high at its highest point.”
Methane gas generated under anerobic conditions within the cell, and other cells at the site, is collected, treated and harnessed by an on-site power plant to generate electricity.
The Landfill Gas to Energy plant is owned and operated by LGI Limited, can generate 14,900MW per year to the electricity grid, delivering power to over 3,200 homes within the region.
Electricity generated by the landfill gas to energy plant and regional solar farms have reduced our carbon footprint, Cr Maddern said.
“Power generated by local solar farm which feed into the grid during the day and power generated by methane gas is feed into the grid 24/7,” she said.
The site is expected to generate power for the next 20 years.