“Mechanical stomachs” full of food-digesting micro-organisms are revolutionising the way Melbourne’s restaurants deal with the mountains of waste they generate each day.
When chef Mark Normoyle ran a waste audit on the major hotel and restaurant complex he was running a few years ago he was astounded by the results.
“We found out we were throwing out 300 to 500 kilograms of organic waste,” he said. “Every day.”
Mr Normoyle describes himself as a “green warrior” – but he is also a pragmatist and was charged with turning a profit.
“My first thought was: ‘wow that’s all money … in the bin,’” he said.
Until recently Mr Normoyle was executive chef at the RACV City Club, a role he held for 16 years.
“We’re a five-star hotel, we have multiple restaurants, we host functions for hundreds of people, so you’re talking offcuts, vegetable scraps, table scraps, leftovers from the breakfast buffet…”
The head chef set about searching for a means of disposing of all that organic waste on site.
The answer he came up with was a relatively novel technology in Australia – one which converts food waste to water.
Tas Papas, the Australian general manager of ORCA Enviro Systems, says the aerobic food digester is like a “mechanical stomach”.
“The unit itself has a tank inside it that houses natural micro-organisms … [that] digest the food aerobically to a liquid state,” he said.
“That liquid state is then disposed of through a grease trap, or grease arrestor, into the [sewage] system.”
The RACV City Club is one of hundreds of Australian companies to rent an ORCA since it entered the market two years ago.
The City of Melbourne began using one at its Degraves Street recycling facility in May last year.
Every month that facility alone reduced methane emissions by 4.85 kilograms and carbon dioxide emissions by 6.75 tonnes, the company claimed.
But it does not just divert food waste from landfill, Mr Papas said.
“Our big benefit is being able to, most efficiently, recycle food waste at the source, so that means we get away from big garbage trucks on the road burning up diesel and causing traffic.”
The company claims it saved 700 litres of diesel per month by not requiring garbage trucks to pick up the food waste that was turned to water at the Degraves Street facility.
He said that by dealing with all its food waste on site, RACV City Club was able to reduce the number of skip bins it required from three to two. Not only did that save the company money, it meant less smelly, vermin-attracting waste was stored on site.
“While we were only one venue in Melbourne, if you think about all the restaurants and the clubs and the hotels, if they were all producing more than 300 kilos of food waste a day like we were … that’s just an astronomical amount of food going into the bin.”