Digester could drop costs

A local trade waste company owner says using SA Water's new anaerobic digester for co-digestion to process trade waste in Port Lincoln could save local businesses thousands in transport costs.

DIGESTER: SA Water's Nathan Trezise and Kellie McDonald inspecting a lagoon within the Billy Lights Point wastewater treatment plant. Image supplied.

DIGESTER: SA Water's Nathan Trezise and Kellie McDonald inspecting a lagoon within the Billy Lights Point wastewater treatment plant. Image supplied.

The upgrade to the Billy Lights Point wastewater treatment plant will allow high-saline organic waste from local seafood industries to be processed but the new digester will not initially be used to co-digest waste from local businesses.

Local Liquid Waste Removal owner Andrew Foster is one of two licensed local trade waste contractors and transports his liquid waste to SA Water's co-digestion facility in Glenelg after the Environment Protection Authority shut down the local grease pond.

Mr Foster said the majority of the cost for his customers - about 60 per cent - was for transport.

"As close as we can work out, between Veolia Environmental Services and Local Liquid, there is approximately 1300 kilolitres of water transferred to Adelaide each year...this equates to around $260,000 dollars a year wasted in transport alone," he said.

SA Water asset operations and delivery manager Mark Gobbie said high-strength organic waste was inappropriate for discharge to sewerage networks due to the impact on infrastructure and odour.

"Co-digestion involves the digestion of high-strength organic waste from industry, which is combined with waste sludge from the sewage treatment process, to increase the production of a renewable energy source called biogas," he said.

"If local industrial waste is deemed suitable, there could be an opportunity for it to occur within the digester being built at the Billy Lights Point plant."

He said SA Water would consider the viability of co-digestion in the coming months.

Mr Foster said waste he sent to Glenelg had been deemed viable there.

"When we pick up trade waste from a restaurant or a fish factory it all goes into the tanker and is put through the co-digester at Glenelg."