Street sweepings once destined for landfill will be recovered through innovative washing plants in Melbourne.
Cleaning up Victoria’s streets cost more than $90 million in 2010-11 – or $16.04 for every ratepayer in the state.
That’s according to statutory authority Sustainability Victoria’s 2010-11 data, which puts the price of street sweeping services at more than $58 million a year – covering by 76 per cent of the metro region.
It goes on to say that collecting 39,693 tonnes of roadside litter and illegally dumped rubbish cost local governments almost $10.6 million annually to collect.
The pricey burden to councils drew the attention of Melbourne resource recovery specialists Repurpose It and integrated infrastructure and environmental services provider Citywide, which two years ago opened the nation’s first street sweeping and recycling plant at Dynon Rd, in West Melbourne.
“We need to be educating the community on where litter ends up, because quite often it ends up on our road network and that comes at an increased cost to councils,” says Repurpose It’s George Hatzimanolis explains.
“This is ratepayers’ money that could be spent and invested in critical infrastructure for our communities.”
Street sweepings comprise grit, plastic, paper, cardboard, timber, litter and glass, with much of it recoverable with the right technology in place.
With the capacity to process about 22,000 tonnes of materials per annum, Citywide’s Dynon Road facility is operated in partnership by Repurpose It. It is a dedicated street sweeping and pit cleaning waste plant for the Melbourne Central Business District and surrounding areas.
Matthew Whelan, Citywide’s Executive Commercial and Innovation, says the partnership has allowed the companies to maximise productivity and the facility’s sorting capability. He says this allows the organisations to continue to grow their volumes, products and recyclable streams for the plant.
“All of our clients are experiencing increased volumes of street sweeping and other waste streams and the ongoing development of the facility is part of the commitment of Citywide to provide leadership in the areas of resource recovery, sustainability and liveability in our cities and local municipalities,” Matthew says.
George says a typical local government area will produce about 3500 to 5000 tonnes of street sweepings per annum. He estimates 95 per cent of the street sweepings generated through standard road maintenance are recoverable, with the remaining residuals containing litter such as paper, plastics and cardboard. Other areas of road maintenance are also part of its street sweeping recovery, including catch basin cleanings and pit cleanings comprising sand, grit, coarse organics and silt/fine organics.
“Catch basin cleanings and even pit cleaning can cause issues in urban environments, particularly if you’ve got an oil spill – which can mean material emerging from the pits and drains is contaminated. These are particular challenges in Melbourne’s Central Business District, so there is often stringent environmental compliance required and that’s why street sweepings can only be disposed of at a licenced facility with regimented testing,” George says.
Repurpose It’s washing plant technology will focus primarily on manufacturing sand and washed aggregates at high output. George says it complements the Citywide facility.
“While our facility will wash a number of materials, we focus predominately on excavated materials to make manufactured sand,” George says.
“We partnered with CDE Global who offered a turnkey solution and the world’s leading construction and demolition washing plant.” The plant, which won’t be operational until October this year, will wash and recycle the ordinarily difficult to recover sand, silt and aggregates through advanced screening, scrubbing and water treatment. Glass fines will also be a notable feature of the washing plant, eliminating contaminants such as alcohol and cane sugar caught up in glass through the commingled bin.
At full capacity, it will handle up to 250,000 tonnes per annum comprising a variety of waste materials from the construction industry.
“Excavated materials will go over a wet screening, scrubbing and sand processing plant and we’ll be able to recover any of the available sand and grit for reuse which really closes the loop. Industrial ecology is the core of our business,” George says.
“We are able to wash and produce this material to specification – it’s a direct substitute for natural sand.”
He says Repurpose It has made arrangements to partner with Australia’s leading construction material providers, as the material will be sold on to owners of asphalt and concrete plants and developers of road base. These companies will turn the materials into a finished product for use in road building.
This article appeared in the May 2018 issue of Waste Management Review.