Storage tank water mixer helps CA city maintain high water quality

A potable water storage tank operated by Stinson Beach County Water District in Marin, CA, received a water mixer to maintain high water quality.

STINSON BEACH, CA, Dec. 4, 2013 -- A potable water storage tank operated by Stinson Beach County Water District in Marin, Calif., recently received a water mixer to maintain high water quality.

Provided by PAX Water Technologies, a company specializing in technologies for water distribution systems, the mixer mimics nature's flow patterns, observed in whirlpools and air currents, to eliminate thermal stratification and blend fresh water entering the tank with water already stored inside the tank.

The 210,000-gallon Steep Ravine tank contains potable drinking water for Stinson Beach residents and reserves for emergency situations, such as fires and earthquakes. During periods of low water usage, water in the tank becomes thermally stratified. This layering and separation of different water temperatures can cause chlorine disinfectant to evaporate from the upper water layer in the tank.

Unmixed tanks can create water quality issues like high water age, residual loss, bacteria growth, and microbial contaminants. To deal with these issues, municipalities typically dose additional chemical disinfectant into tanks and in serious cases, flush or dump water. Before the mixer was installed, operators at Stinson Beach measured a 3 °F difference between the upper and lower layers of water inside their storage tank. After just three hours of operation, the mixer had fully blended the entire storage tank and created homogenous water temperature.

"We noticed an immediate difference after installing the PAX Water Mixer in the teep Ravine tank -- the chlorine level has stabilized and the stratification inside the tank is gone," said Ed Schmidt, general manager of Stinson Beach County Water District.

Dr. Peter S. Fiske, CEO of PAX Water Technologies, added, "Unlike lakes, which are mixed by the wind, drinking water storage tanks are sealed and very little mixing occurs. The PAX Water Mixer reintroduces nature's strategy for keeping water fresh and safe: constant motion."

About PAX Water Technologies

PAX Water Technologies delivers innovative water quality solutions, inspired by nature and backed by science, to safeguard drinking water for municipalities and the communities they serve. The company’s biomimetic mixing technology efficiently circulates the water held in storage tanks to eliminate thermal stratification and reduce high water age, disinfection byproducts and nitrification.


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