Unitywater has awarded a contract for the $73.9 million upgrade to the Kawana Sewage Treatment Plant (STP) located on Queensland’s Sunshine Coast, which aims to increase capacity to the area.
The design and construction contract was awarded to engineering group Monadelphous and will increase the plant’s current treatment capacity from supplying around 90,000 people to 200,000.
The 35-year-old STP currently services communities from the southern end of its catchment at Pelican Waters through to Buddina, and the upgrade will mean sewage from South Buderim, Chancellor Park and Sippy Downs, which is currently treated at Maroochydore STP, will be sent to Kawana STP.
Unitywater Executive Manager Infrastructure Planning and Capital Delivery, Simon Taylor, said the upgrade would incorporate a biotechnical process that requires less infrastructure to be built.
“The moving bed biofilm reactor (MBBR) process is a type of wastewater treatment where small plastic pieces known as ‘carriers’ are used to grow special bacteria, which then consume the impurities from incoming sewage,” Mr Taylor said.
“This technology requires less space than other treatment processes as the bacteria can be concentrated into a smaller area.
“The upgrade will also include a new anaerobic digester where special bacteria turn sewage into methane-rich biogas, and a large gas engine that will turn the biogas into electricity.
“By using this engine, we expect to cut our electricity bills at Kawana STP by about one third.”
Mr Taylor said Unitywater was also carrying out a feasibility study at this STP to examine how other waste types, like fats, oils and greases from restaurants and cafes, can be turned into energy.
Construction will start in April 2017 and is expected to be completed in December 2018.