Reservoir Inversion Solves City Water Problems
Bad taste and odor in the drinking water at Middletown, New York plagued residents for years. Also, a black coloration in the water often stained residents’ clothing during laundering. These problems were solved after Bill Johnson, Middletown’s Deputy Commissioner of Public Works, discovered high levels of manganese in water samples from their reservoirs. The manganese washes into the water with soil during heavy rains. He also knew that algae in the town’s reservoirs caused the taste and odor problems in the drinking water.
Johnson then consulted with CLEAN-FLO International to solve the coloration problem and find a better solution to the annual algae problem. CLEAN-FLO installed “continuous laminar flow inversion” systems in Highland and Monhagen reservoirs. CLEAN-FLO’s systems continuously bring water up to the surface from the reservoir bottom without creating turbulence. Turbulence would have mixed the low-oxygen bottom water and the toxic gases, that accumulate at the bottom of the reservoirs, with the rest of the reservoir water. Turbulence would create even worse problems than the residents already had. Within weeks of the installation, there were dramatic improvements in transparency, and manganese levels dropped to near-zero. The taste and odor problems disappeared and the residents stopped complaining.
“Algal growth, foul-tasting and odorous water are universal problems for people in charge of lakes, rivers and reservoirs. Manganese often stains clothing black. Taste and odor are usually caused by blue-green algae or by gases in oxygen-depleted bottom water that rise to the surface during spring and fall turnovers. Both problems are eliminated by continuously rolling the water over. Spring and fall turnover have been nature’s way of restoring water quality for centuries, but now the water bodies are so polluted that the process needs to be accelerated.
Clean-Flo’s inversion system gently turns the reservoirs’ water over. The inversion brings the foul-smelling gases up to the surface where they are neutralized by the atmosphere. Inversion also takes oxygenated surface water down to the bottom where the oxygen kills the bacteria that produce the foul-smelling gases. The algae, which only grow on the surface, are taken to the bottom where it cannot grow because of lack of sunlight. Finally, by oxygenating the entire reservoir, manganese that causes the discoloration of the clothing, is oxidized and deposited on the bottom. Both oxidized manganese and oxidized iron then become useful in binding the phosphorus and nitrogen to the bottom sediment, making it no longer available for algal growth.
Clean-Flo’s inversion process is more effective than ordinary aeration systems. It is less costly than treating all incoming water, which is impossible, anyway. Most incoming water, such as “non-point source” watershed runoff cannot be treated at all before it enters the reservoirs.
“The CLEAN-FLO system solved Middletown’s taste and odor problems in a more efficient and cost-effective manner,” said Johnson, “it also solved our black water problems which was an added bonus to the city. This technology has been a tremendous benefit to our water treatment efforts.”