With a population of almost 124,000 people and up to 40,000 additional visitors each night, sustainable management of wastewater and domestic garbage generated is a key challenge for the City of Cairns. Faced with its landfill quickly running out of space, and no chance of gaining approval for a new site on the coast, Council sought out alternative technologies.
“With landfill an unsustainable method of disposal, and transporting waste to a new site on the Atherton tablelands economically prohibitive, Council has entered a 25 year contract, to compost kerbside waste with sewerage sludge from our waste water plants,” said Brian Smyth, General Manager Cairns Water.
Under this agreement, Council has provided the land for Bedminster Bioconversion Pty Ltd to construct its state of the art Resource Recovery Centre. The $27 million plant covers an area a little over the size of two football fields. Expected to come on line in April, organic materials are separated from the waste stream and the composted with sewerage sludge.
The Resource Recovery Centre, located in Cairns will process and recover valuable resources for the City of Cairns, and the neighbouring Shires of Mareeba and Douglas. With 30 years of experience, the Bedminster Technology has stringent environmental controls with all processing taking place inside the new complex. Its enclosed system means odour is totally controlled and there is no risk of contamination to stormwater or ground water.
The composting process is aerobic producing no methane, a key contributor to Greenhouse gases from traditional landfill operations. This process can reduce waste going to landfill by at least 70 percent. Materials that cannot be composted are deposited to landfill but without the problems of methane or leachate. The Bedminster end product is a fertility enhancing, safe and effective soil conditioner, ideal as a replenishment Australia’s depleted topsoils. The product can also be used as a renewable fuel source for local industry, such as sugar refining, for the generation of electricity.
Under this public/private partnership, Bedmister has built and will own and operate the process plant. The three Councils pay a monthly fixed fee and a set payment for every tonne processed. The Bedmister Technology was selected following a formal tender process. The contract is in three phases – gaining the necessary approvals; design and construction; and operation.
The plant, for all intents and purposes, looks like a large warehouse. Through Bedminster’s system of biofilters, comprising layers of gravel, compost and wood chips, any unpleasant odours are eliminated. The Cairns plant is the largest to be constructed in Australia to date, with a smaller plant in Port Stephen and another servicing the Southern Metropolitan Regional Council in Perth.
“This major project is more than meeting Government targets to reduce our waste to landfill by 50 percent,” Brian Smyth said. “It is also meeting community demands to protect the environment by reducing, re-using and recycling waste.”
