Mt. Dell Reservoir, Utah,  Treatment Equipment Installed

Aeration circulation device to freshen water stored in the reservoir

September 23, 2004

On July 15, 2004 the SolarBee® is lowered into Mt. Dell Reservoir, located in Parley’s Canyon, Utah

(Salt Lake City, Utah) This summer, Salt Lake City began testing a new mixing unit on Mountain Dell Reservoir, to help maintain the quality of water in the lake. Mt. Dell Reservoir is located 5 miles east of Salt Lake City, Utah in Parley’s Canyon. The 3,100 acre-foot storage reservoir provides drinking water supply to Salt Lake City water customers.

As a result of 5 years of drought, Salt Lake City Department of Public Utilities (DPU) has stored conserved water supply in Little Dell and Mt. Dell reservoirs to ensure adequate water supply for the City’s water customers in the event of an emergency or the continuation of the drought. Because of the drought and  this water management decision, the water in the two reservoirs has been aging. This situation led to a concern, especially in the smaller Mt. Dell Reservoir, that problems associated with anoxic (absence of dissolved oxygen) conditions may be developing in the lower water levels of the reservoir. An anoxic layer turnover can cause harmful algae blooms, taste and odor in the finished drinking water, inorganic chemical release from the sediments, fish kills and excessive shoreline vegetation. 

In an effort to avoid water quality problems in Mt. Dell Reservoir, which supplies water directly to the Parley’s Water Treatment Plant, DPU sought a means of de-stratifying the water layers within the reservoir and keep the reservoir water mixed. DPU water quality administrator Florence Reynolds and her staff reviewed alternatives to achieve the objectives, and selected a treatment device manufactured by SolarBee®. The treatment device was installed in Mt. Dell Reservoir on July 15, 2004.

A schematic of the operation of the SolarBee®. Water is circulated within the reservoir to a depth of 100 feet, de-stratifying the various layers of water quality within the lake and preventing eutrophication.

Looking much like a moon landing device with solar panels floating on the surface of the reservoir, the SolarBee® circulates the water to a  depth of  100 feet deep. at pumping rates  up to 10,000 gallons per minute. It is silent, solar powered and has no infrastructure requirements. Ideally, the unit will allow for the mixing of the reservoir so that the lake doesn’t stratify, turn over the heavy nutrients at the lake bottom and cause algal blooms. These blooms impact the treatability, and esthetic qualities ( taste and odor) of the water.  According to Reynolds, “Its our hope that by being pro-active we can halt or control eutrophication in the reservoir.” She adds, “It is more effective to treat the reservoir water so as to avoid water treatment problems and possible taste and odor problems in the water distribution system.”

Two month’s data indicate that the SolarBee® is meeting DPU’s expectations. Turbidity, temperature and dissolved oxygen data show that stratification within the reservoir is not taking place since SolarBee® has been in operation.

Additional information may be obtained from Salt Lake City Department of Public Utilities: florence.reynolds@slcgov.com