FPUD to get solar-powered mixing unit

The Fallbrook Public Utility District will add a solar-powered floating mixer unit at FPUD's Red Mountain Reservoir.

FPUD's board voted 5-0, June 19 to award Medora Corporation a $74,016 contract for the solar mixing unit.

"This will help so we can use more of the water in the reservoir if we ever have to drain it," said FPUD acting general manager Jack Bebee, who added that the solar floating mixer will also improve water quality.

Suspended solids settle out in Red Mountain Reservoir over time, which creates sediment on the floor of the reservoir. The sediment must be removed periodically to maintain water quality, which requires the draining of Red Mountain Reservoir. The bottom 24 feet, which equates to 65 million gallons, are at an elevation which does not provide adequate pressure to the system, so the water must be discharged into the nearby creek. The solar mixer will minimize the settling out process and reduce the need to drain the reservoir for cleaning.

The buildup of sediment also degrades the water quality, so in order to meet water quality standards, the reservoir's ultraviolet treatment system must increase the reactors' power output, which thus increases FPUD's electricity costs, and the water quality improvement will thus also reduce FPUD electric expenses.

A floor-mounted tank mixer was deemed not to be feasible for Red Mountain Reservoir. No power source for a tank mixer is readily available, maintaining a floor-mounted mixer would be labor intensive, and tank mixers lack the pumping capacity to mix a facility the size of Red Mountain Reservoir, which has a capacity of 440 million gallons.

FPUD staff review determined that Medora's Solar Bee unit was the only product capable of meeting the district's needs for Red Mountain Reservoir. The Solar Bee model is capable of mixing 5,000 gallons per minute.