Torrens Lake is the site today (Tuesday 10 March) of a further stage in an innovative trial testing the effectiveness of hydrogen peroxide for controlling blue-green algae.
The trial, between the University Footbridge and the Albert Bridge, involves adding low concentrations of hydrogen peroxide to the water from an SA Water boat specially designed for the purpose.
Torrens Lake upstream from the City Bridge (King William St) was closed this morning to allow operators to apply the hydrogen peroxide (H2O2), which will be active for a limited time before breaking down naturally to water (H2O) and oxygen (O2).
The section of lake upstream from the University Footbridge will remain closed until Thursday afternoon to allow for monitoring.
Katharine Ward from Natural Resources Adelaide and Mt Lofty Ranges said the trial was another step in determining whether hydrogen peroxide could be used to combat blue-green algal blooms in water bodies such as Torrens Lake.
“Since 2011 we’ve tested a variety of measures to reduce the impact of bluegreen algae in Torrens Lake, and by using flows of fresh water from upstream storages we’ve been able to keep the lake free from closure for the past five years, and improved water quality along the Torrens from the hills to the coast.
“The use of hydrogen peroxide provides another tool for controlling blue-green algae, which would be a great environmental outcome and an Australian first for recreational water bodies.”
Ms Ward said today’s trial followed laboratory tests, pond experiments and small scale use in the Torrens in 2016 and 2017. This allowed the project team to fine tune the application method and show that weak concentrations of hydrogen peroxide are effective in controlling blue green algae while not harming other aquatic life.
“We’re hopeful that as we build knowledge and expertise in using hydrogen peroxide, it might also become one of our methods for controlling blue-green algae, and so reduce our reliance on fresh water flows.”
The River Torrens Water Quality Improvement Project was developed with the support of the Adelaide and Mount Lofty Ranges Natural Resources Management Board, the Department of Environment and Water, SA Water, the Environment Protection Authority, CSIRO and the City of Adelaide.