Mount Gambier City Council enables ultrasonic technology to remove harmful blue and green algae in city valleys.
- Water tests reveal harmful blue and green algae in Valley Lake
- Ultrasound used to control algae levels does not affect other aquatic life
- Algae levels are higher in warmer months
This follows months of testing on the lake, which is a popular spot for waterskiing and recreational boating activities.
Two floats were installed on Valley Lake in January, one to monitor water quality and the other to emit ultrasound.
The council worked with a water testing company to collect physical samples and measure water quality at various depths.
Testing revealed the presence of harmful blue algae, green algae and cyanobacteria.
The council’s Environmental Sustainability Officer Aaron Izzard said the algae would be controlled by ultrasonic technology.
“[The float] Sends an ultrasonic signal into the water that targets only algae and bacteria,
“[It] Destroy the components within those organisms that allow them to float. So they sink to the bottom and die. ”
Ultrasound tests were performed in cool weather.
The council is currently waiting to see how effective this technology is during the summer months when algae are more prevalent, and will consider using it long-term.
Ultrasonic floats will be operational in September and will continue through the fall.
algae can cause disease
Izzard says it’s important to control algae levels.
“There are many types of algae, most of which are benign, but some of which are harmful to humans,” he said.
“There are certain species of algae that can make people sick—not very sick, but a little nauseating.
“We want the lake to be usable for water recreation, so ideally we want to control the harmful algae and bacteria there.”
The technology specifically targets algae and won’t harm other aquatic life, Izzard said.
“It has been tested and not found to be harmful to other types of aquatic life. It only targets bacteria and algae.
“Does not affect insects, animals or fish of any kind.”
Boats are less susceptible
The floats are clearly marked and Izzard said they are unlikely to affect recreational users of Valley Lake during the summer months.
“We tried to make them clearly visible. They’re not that big in the grand scheme of the lake,” he said.
“People can still go around the lake on jet skis and boats. There is still plenty of room for water sports on the lake.”
Izzard said ultrasonic technology is a cost-effective way to control algae levels.
“If you look at the annual cost, it’s not a big investment, especially if you want to make the lake available for more water sports,” he said.
“We went out to bid on this project and had all sorts of proposals, some cost more, but this one was very cost effective.”