Press Release

Stinson Beach Installs PAX Water Mixer in Storage Tank to Maintain High Water Quality

Mixer introduces nature’s flow pattern to eliminate stratification and prevent chlorine disinfectant loss


STINSON BEACH, Calif. – December 4, 2013 – PAX Water Technologies, the leader inadvanced technologies for water distribution systems, today unveiled the installation of a PAX Water Mixer in a potable water storage tank operated by Stinson Beach County Water District in Marin, Calif. Located off of Panoramic Highway, 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 “Steep Ravine” 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. 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.

“Stinson Beach enjoys great drinking water quality, and we want to maintain that high quality in our storage tanks,” said Ed Schmidt, General Manager of Stinson Beach County Water District. “We noticed an immediate difference after installing the PAX Water Mixer in the ‘Steep Ravine’ tank – the chlorine level has stabilized and the stratification inside the tank is gone.”

The PAX Water 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. 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. 

“Unlike lakes, which are mixed by the wind, drinking water storage tanks are sealed and very little mixing occurs,” said Dr. Peter S. Fiske, CEO of PAX Water Technologies. “The PAX Water Mixer reintroduces nature’s strategy for keeping water fresh and safe: constant motion. We are excited that our mixer is being used by one of our local municipalities to help keep water fresh and tasting great.”

The PAX Water Mixer was invented by Australian naturalist and entrepreneur, Jay Harman of PAX Scientific – a biomimicry-based engineering, research and design firm in Marin County. Mr. Harman recently published The Shark’s Paintbrush, a book on how nature inspires innovation.

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.