Swift Creek Reservoir

LG Sonic Ultrasound Technology

Advancing Water Quality through Innovation

Despite their natural occurrence, the high presence of algae can impact water quality and produce unpleasant smells and tastes. Some types of algae, such as blue-green algae (Cyanobacteria), may even produce toxins harmful to humans and aquatic life. Anabaena is present in many natural waters including the 1700-acre Swift Creek Reservoir.

The Chesterfield County Department of Utilities is vigilant in monitoring and managing Anabaena growth as well as other potential problem algal species. To tackle this challenge, Chesterfield County Utilities has placed a strong emphasis on innovative technologies, including the LG Sonic MPC-Buoy system. This system uses low-power ultrasound to create a constant pressure cycle around the algal cells, interrupting their buoyancy regulation and disrupting their ability to access sunlight and nutrients. (Ultrasound targets the problem algae, causing them to safely sink to the bottom of the reservoir without harming water quality. Due to the limited light at deeper water depths, the algae are unable to survive.)

The MPC-Buoy has no negative impact on aquatic life and is a cost-effective solution to maintaining water quality. The units are triangular in shape and work using environmentally-friendly solar power.

Consistent Water Quality, Trouble-Free Summer

Since the installation of LG Sonic technology in 2017 with two LG Sonic MPC-Buoys, the water quality in Swift Creek Reservoir has been consistently excellent in the intake bay where the MPC-Buoys have been strategically installed.Even during the hot summer months, when algae blooms are most common in the United States, the Swift Creek Reservoir Intake Bay remained to be good quality. Real-time water quality data collected by the buoys has showed positive results from July 1 to Sept. 30, with measurements consistently rated as "Excellent to Good."

_{The white triangles indicate the approximate LG Sonic buoy locations at the water treatment intake bay in the Swift Creek Reservoir.}

Advanced Monitoring Systems Above and Below the Surface

To further enhance its water quality monitoring capabilities, in November 2022, Chesterfield County Utilities added a third upgraded unit, the LG Sonic Vertical Profiler. This system provides high-resolution measurements of water quality parameters at multiple depths, giving an in-depth view of Swift Creek Reservoir. With this advanced monitoring system, Chesterfield County is even better equipped to monitor, predict, and control water quality in the reservoir. This is the first deployment of the LG Sonic Vertical Profiler in the entire United States. As this is a new technology, the Utilities Department is providing useful feedback to improve the software’s data display to increase its user friendliness.

Plant Manager David Sirois emphasizes the importance of a holistic approach to monitoring algae blooms, recognizing that it exists not only on the water's surface but throughout the entire water column: "The unit that we got this year is special in the fact that it can go up and down the water column. Being able to survey throughout the water column gives us a better picture of what's going on with blue-green algae and consequent water quality."

With cutting-edge technology and a commitment to improving water quality, Chesterfield County is setting a high standard for water management and ensuring that its residents have access to safe and high-quality water.

_{One of the LG Sonic buoys located in the water treatment plant intake bay.}

Environmental Engineering Swift Creek Reservoir Water Quality Reports

After 10 years of consistent monitoring, the Addison-Evans Water Plant laboratory took part in a review of the Swift Creek Reservoir water quality sampling and analysis program. View the Environmental Engineering Swift Creek Reservoir Water Quality Reports Archive.

It was decided more emphasis will be placed on newer technologies by use of probes and sensors. The laboratory uses more probe-based sondes in the field and monitors real-time numbers by way of the LG Sonic buoy system.

Currently, data end users and experts in interpretation of reservoir water quality place more emphasis on total phosphorus and total nitrogen. It was found that the time and effort to measure nitrogen and phosphorus components of orthophosphate and ammonia is less valuable; therefore these parameters will be dropped and more time will be spent measuring and reacting to the newer technology data.

These changes will ensure the reservoir program is current with technology/theory, data processing efficiency and enable staff to concentrate efforts on issues important to the continued monitoring of water quality in the reservoir.

For any questions please contact the Addison-Evans Water Plant laboratory at 804-748-1310 (press 3). For previous updates and reports, please email Department of Utilities.