The city of Bowling Green, Ohio, draws water from the Maumee River into its reservoir prior to treatment to supply safe potable water to its citizens. However, in summer, the Maumee River is typically overwhelmed by toxic cyanobacteria for several months. Toxic cyanobacteria bloom events can be serious.
Because the reservoir only holds about 30 days’ supply, the city is forced to draw this cyanobacteria ladened water into the reservoir. For several years this became a problem as cyanobacteria began to dominate the phycological profile of the reservoir to the same degree as it does in the reservoir.
To resolve the issue, in the late 2000’s a bottom based aeration system was installed in the reservoir, but this did not control the cyanobacteria and by 2016 it proved necessary to add the use of a peroxide-based algaecide to the reservoir.
These two interventions combined were unable to control the situation. In late 2016 the proportional dominance of cyanobacteria in the river and in the reservoir were still about the same at approximately 68%. The absolute numbers in terms of cell count were slightly reduced in the reservoir due to the application of algaecide, but this did nothing to constrain the dominance of cyanobacteria.
In April 2017, the City of Bowling Green decided to install Rapid Acting Dissolved Oxygen Restoration (RADOR) technology from Clean-Flo International, a US-based leader in biological water management solutions for managing water quality. Numerous studies have demonstrated that high, stable oxygen levels reduce nutrients and minerals in the water column and can keep phosphorus locked into the organic sediments.
“By increasing dissolved oxygen levels throughout the water column, the RADOR system initiates a sequence of events that bio-dredge mucky sediment, control aquatic weeds, improve water quality, reduce organic muck, nutrients, odor, harmful gases, and coliform bacteria. This helps to restore the nutrient clearing capacity of the food web by improving fish growth and health,” explains says Dave Shackleton, president of Clean-Flo International.
Clean-Flo designs its RADOR systems using compressors of various sizes based on the lake and application, along with self-sinking airline and diffusers that maintain full oxygenation from the bottom to the surface of the water.
Data collected a year later showed that the total phycological cell count was reduced by around 75% and cyanobacteria were all but eliminated completely. By 2018, despite having to draw water from the river at a time when cyanobacteria levels were extremely high, total cell count, and cyanobacteria levels were well controlled in the reservoir.
“The implementation of the… RADOR system enhanced water quality and it is an important tool for its reservoir management.” Daryl Stockburger, Assistant Director of Utilities, City of Bowling Green.
For more information, visit www.clean-flo.com; email [email protected]; or call 1-800-328-6656.