LAKE Macquarie City Council is trialing the use of crushed glass as a substitute for virgin sand in civil engineering works across the city – and other neighbouring councils might follow their lead.
The council believes the project makes financial and environmental sense, and could even prove to be part of a solution to the nation’s growing waste problem.
The Hunter-first project is on track to reuse thousands of tonnes of glass every year, with the potential to reuse all 12,000 tonnes collected across the region if other councils join the project.
Mayor Kay Fraser said glass bottles, jars and other items collected from household recycling bins would continue to be sorted and processed, as usual, at a materials recovery facility at Gateshead.
But, rather than seeking glass recycling solutions interstate, council would trial the reuse of “glass sand” manufactured at a custom-built plant at Wyong, she said.
The glass sand has similar applications to normal sand and can be used as bedding material in drainage projects and other civil works in public and private development.
“There is a growing need across Australia to find an end use for recycled glass,” Cr Fraser said.
“This is very sustainable, very environmental, and it’s about us looking after our own waste. We’ve heard about the war on waste, and this is Lake Macquarie leading the way.
“With companies finding it cheaper to import new glass than buy recycled, we need to start coming up with innovative, cost-effective alternatives.
“This collaborative project could help solve a national crisis in our own backyard.”
Council’s planning and sustainability manager Alice Howe said more than 5000 tonnes of glass were collected for recycling annually across Lake Macquarie.
“Our strategy is twofold: we are demonstrating the suitability of recycled glass sand for our own civil works program, and have amended our engineering guidelines to specify how this material can be used in development across the city,” Dr Howe said.
Delegations from seven neighbouring councils from the Hunter and Central Coast were at Fishing Point on Wednesday to see the glass sand up close, and witness it being used by CiviLake staff in a drainage project.
The washed glass sand feels like coarse builder’s sand. A close inspection revealed tiny granules of green, brown and clear glass, evidence of a variety of sources.
If the growing stockpiles of glass for recycling wasn’t reason enough to trial glass sand, the increasing cost of virgin sand driven in part by Sydney’s growing demand for the resource, made the trial doubly worthwhile, the council said.
“We think this is going to be a net beneficial arrangement for our waste services,” Dr Howe said.
“The cost of this product is comparable to, or cheaper than, the virgin product, so we’ll have savings in our civil works program.
“But it will also enable us to generate revenue from the container deposit scheme.”
Council was required to demonstrate that it had beneficially re-used materials that it had collected through the Return and Earn scheme.
“So that provides an income source to support cost reductions across our waste services.”
Dr Howe said council aimed to gradually increase the amount of recycled glass that is processed into glass sand.
“If the rest of the region follows our lead, this initiative could close the loop on thousands of tonnes of glass each year,” she said.
Previously, much of Australia’s recycled glass went interstate for processing and reuse. Recently, however, much of this material has been stockpiled.
Dr Howe said the glass sand complied with Australian standards, and was equivalent to virgin sand in engineering applications.
“And it’s actually got a lower silica content so, from a dust handling perspective, it’s safer than natural sand.”