The Bondi Gobbler cutting carbon in Waverley

12 December 2013 — Lettuce scraps, spring onion tops and some very ravenous algae are among the allies Waverley Council is working with to achieve a targeted 30 per cent reduction in carbon emissions by 2020.

Working with Sustainable House sustainability coach Michael Mobbs, the council is trialling an Australian-first food waste composting system with restaurants and cafes in and around Bondi Pavilion, which will take on average 600kg of food scraps produced each day and convert it into compost in just 24 hours.

Waverley Mayor Sally Betts has named the innovative composting unit the “Bondi Gobbler”, and says there are several ways in which the pilot will reduce the carbon footprint of food waste and contribute to council’s ambitious greenhouse target.

First, there is the reduction in truck movements for removal of the waste, which when processed by the Gobbler weighs in at 10 per cent of the raw food scrap mass.

Second, there is the reduction of food waste going to landfill, where the waste would generate carbon emissions as it decays. Instead, the compost produced is being used on the Waverley municipal gardens, and being trucked out to a farmer at Picton, John Fairley, who will use it to fertilise pasture for his dairy herd.

The amount of carbon the fertilised paddocks sequester will be measured to create data on the effectiveness of the whole system for reducing carbon footprints. The use of the compost fertiliser also reduces Fairley’s footprint by reducing the need for chemical fertilisers.

The third carbon-reduction aspect is the data which will be collected on how much power the Gobbler uses, and how much carbon is created by truck movements out to Picton. The Fifth Estate columnist Michael Mobbs has pledged to sequester two tonnes of carbon for every tonne the system creates, practically guaranteeing a carbon-negative outcome.

“We win [with this project] because it is helping us reach our carbon reduction targets,” Cr Betts said.

“It will also have an impact on the bins – council owns and operates and staffs the waste collection service, and currently food waste contaminates things in the regular waste bins which could otherwise be recycled.

“This is a trial, and we will work closely with Michael [Mobbs] to work out any bugs.

“One of the important things about this technology is it doesn’t smell. We did a trial of a small unit in my office, and it didn’t smell. The restaurants at Bondi Pavilion [previously] put the food scraps out at night and they are collected in the morning, so there was a smell issue out the back of The Pavilion. When you take the food waste out of the bins it makes such a difference, which is important for a major tourist attraction.”

The technology uses heat and some very efficient algae to turn any food scraps, including meat and dairy, into compost in 24 hours. The speed is a major advantage, allowing restaurants to contribute their large daily volumes and have them rapidly converted.

There is a business advantage for the restaurants and cafes, as waste disposal fees in Waverley are charged by weight, and food scraps form a significant proportion of the weight. Take them out of the equation and the financial saving is considerable. Mobbs estimates this could result in as much as a 5-10 per cent reduction in business costs.

For Betts, the goal is to successfully refine the system, and then educate and encourage other Campbell Parade cafes and restaurants and wider community members to use The Bondi Gobbler. This fits into council’s other big sustainability goal of a 75 per cent reduction in waste going to landfill by 2020.

Waverley Council is working closely with Randwick and Woollahra councils on a range of carbon-reduction, waste minimisation and sustainability strategies.

For Betts the motivation is simple: she and her local government colleagues aim to make their community a leading example of sustainability.

The Bondi Gobbler from Digital Storytellers on Vimeo.