Syracuse Department of Water mitigates algae with ultrasonic technology
The Syracuse Water Department (SWD) is responsible for managing an unfiltered drinking water supply for Syracuse, New York. The source water is Skaneateles Lake, located in the Finger Lakes region of New York State, approximately 20 miles southwest of the city.
Open water presents challenges
SWD’s water distribution system includes one open water reservoir that has a capacity of approximately 120 million gallons. Open water reservoirs are challenging to manage during the summer and fall months due to elevated water temperatures and abundant sunlight, which can stimulate uncontrolled algae growth.
Historically, the city would apply copper sulfate to the reservoir during elevated algae counts or spikes. Treatment effectiveness varied depending on environmental conditions, algae species targeted, and uniformity of dispersion.
Because algae levels rise significantly during warmer months, SWD consistently treated the reservoir with between 6,000 and 15,000 pounds of copper sulfate per year to manage algae counts. However, once the copper sulfate was depleted, favorable conditions for algae growth would return. Algae counts would frequently return to pre-treatment levels within several days of applying copper sulfate and the process would continue until water temperatures decreased significantly in late fall.
Watch a video interview with Rich Abbott, public health sanitarian with the Syracuse Water Department, discussing the project.
Ultrasonic treatment solution
Looking for alternatives to copper sulfate, a new approach to algae control employing ultrasonic devices was tested. The units emit sound waves with various frequencies that interfere with buoyancy regulation.
During this work, SWD’s ultrasonic units were supplied by SonicSolutions LLC, now SonicSolutions Algae Control LLC. In 2022 the city deployed its latest ultrasonic unit, a Pulsar 4000 unit by WaterIQ Technologies. This unit emits more than 2,000 ultrasonic frequencies from four separate transducers to suppress algae and has been effective in controlling blue-green algae counts.
Weather conditions throughout the summer and fall of 2022 were extremely warm, resulting in Skaneateles Lake temperatures reaching 80 degrees Fahrenheit. Even with the favorable conditions for algae growth in the reservoir, a copper sulfate treatment was not necessary.
Compared to ultrasonic systems that suppress algae growth, SWD found that, although copper sulfate works immediately to knock down algae counts, it fails to provide sustainable effects. Several days after treatment, the target algae “rebounds” to levels similar to the original algae counts. SWD’s transition from copper sulfate to ultrasonic devices has resulted in consistently improved water quality, without the reliance on a short-term, cost prohibitive algaecide.
Results
WaterIQ Technologies’ Pulsar 4000 has demonstrated to be effective in controlling blue-green algae in the SWD’s open water reservoir in 2022 without resorting to chemical applications. It has also proven effective in controlling that algae after initial application.
Deployment of advanced ultrasonic systems, coupled with diffused aeration by Syracuse Water Department, has been a success. The result is enhanced water quality and significant financial savings. WW
Editor’s Note: A video interview with Rich Abbott about this project will publish online in April on www.waterworld.com/videos.
