SA Water’s $18 million, three-year program of sewerage network upgrades in Port Lincoln will progress to its final stages in July 2019, with construction to commence on a new anaerobic digester and associated infrastructure at the Billy Lights Point wastewater treatment plant.
The new wastewater treatment infrastructure will increase the plant’s ability to accept waste produced by local industry, as well as reducing methane emissions and improving odour management.
Anaerobic digesters are large, sealed concrete tanks that heat the solid organic waste from sewage—known as sludge—in an oxygen-free environment, to promote the natural bacterial metabolic processes that break it down.
The older style evaporative sludge lagoons will be decommissioned, with the new digester built within a lowered part of the plant before being painted to blend with the surrounding environment, and screened with additional native vegetation plantings.
SA Water General Manager Asset Operations and Delivery, Mark Gobbie, said the wastewater treatment plant upgrade actively prepares the town’s sewerage network to support growth, particularly in the significant fishing and seafood industry.
“We’ve worked closely with the local industry over the past few years to identify a sustainable solution, paving the way for continued expansion of Port Lincoln’s major economic contributors,” Mr Gobbie said.
“Recently increasing the sewerage pipe network’s capacity has enabled them to discharge previously unsuitable high saline waste from seafood processing into our sewer network, saving local businesses on costly transport to other facilities.
“Combined with our new digester, it ensures we’re improving the long-term operability of the treatment plant for the benefit of our customers.
“Local neighbours can also expect to notice a reduction in periodic odours from the plant once the lagoons are removed—which were intensified by wind and during hot weather—and the more efficient digester and associated infrastructure is constructed.”
With the new anaerobic digester in place SA Water will be able to consider introducing co-digestion at the treatment plant, to further support local industry.
“Organic waste—which would be sourced from local seafood processors and other businesses for co-digestion to help them further reduce transport costs—is combined with sewage sludge in the digester, offering a sustainable alternative that makes use of the otherwise difficult to treat waste,” Mr Gobbie said.
“The co-digestion process is already in place at a few of our larger wastewater treatment plants such as Bolivar and Glenelg, and at those locations helps to increase the renewable energy generated by harnessing the power of biogas, a by-product of treating sewage.”
As part of the wider program, SA Water invested $6 million to increase the capacity of the sewerage pipe network, which included the upgrade of a wastewater pumping station and four kilometres of new sewer main around the Port Lincoln Marina.Construction will be led by South Australian company Guidera O’Connor, with support from local contractors, and is expected to be complete by December 2020.