Restoring Water Quality In A 13,500-acre Drinking Water Reservoir
Grand Lake St. Marys is a large 13,500-acre drinking water reservoir located in west central Ohio. This lake had high levels of phosphorus which led to the growth of cyanobacteria algae. This type of algae can create toxins that are harmful to humans, pets, and wildlife. In drinking water reservoirs, it can also cause unpleasant odors and affect the taste of the water. As a result of the poor water quality, government officials decided to seek out a water restoration method known as alum.
Applying Alum to Restore Water Quality
After learning about the long-lasting effects of alum and its safety, Ohio leaders decided to move forward with a multiyear water restoration project. This drinking water reservoir was the site of the two largest alum applications in the world! During the first year of the project, our team applied over 2.6 million gallons of alum and sodium aluminate to a 4,900-acre area of the lake in 29 days.
The following year, we applied over 2.7 million gallons of alum and sodium aluminate to the same section of the lake in 29 days. Both applications worked to mitigate the high phosphorus levels and balance water quality. With balanced water quality, toxic algae blooms cannot thrive.
Reducing Phosphorus Levels with Alum
After only 27% of the total aluminum dose had been applied, the internal phosphorus loading was reduced by 43% and water column phosphorus decreased by 30-43%.
A team of third-party scientists analyzed sediment samples throughout the lake and confirmed that SOLitude’s GPS-guided application process results in an even distribution of the target aluminum dose, despite high algal concentrations present at the time of application. Government leaders were thrilled to see their drinking water resource restored to a healthy state.
Want to know more about this project?
Click here for a detailed report of our restoration of Grand Lake St. Mary’s.
