In June of 2008 the Santa Margarita Water District replaced a bubbler aeration system with four SolarBees on Oso Reservoir in Mission Viejo Califorina. The OC Register reported on November 2, 2009 that a “foul odor sniffed by residents of Mission Viejo and Rancho Santa Margarita since Wednesday”… “The stench is the result of an algae bloom in the Upper Oso Reservoir sparked by Wednesday’s cold weather and high winds, said Dan Ferons, chief engineer for the water district.”
The water district has taken several steps to bring oxygen levels back to normal and eliminate the odor. Mechanical aeration equipment has been used since Friday to pump air to the bottom of the reservoir. Four solar-powered pumps known as SolarBees have continued to aerate the water.
On Saturday, the water district started pumping fresh water into the lake at the rate of 200 gallons per minute; today, the rate was increased to 1,500 gallons per minute. Two boats were being used today to generate waves in order to spur oxygen intake at the surface. An external pump was also being used today to aerate the water. The water district is also considering use of a mechanical device to pump ozone, whose molecules include three atoms of oxygen, into the lake.