City officials of the Los Angeles area have deposited 20,000 shade balls into the Los Angeles Reservoir, an effort that will save more than 300 million gallons of water annually.
The shade balls, created by a Los Angeles Department of Water and Power (LAWDP) employee, were deployed to "prevent sunlight-triggered chemical reactions, deter birds and other wildlife and protect the reservoir water from rain and windblown dust," a news release stated.
LAWDP added that this project saves more than $250 million in water infrastructure compared to other engineering concepts considered to bring the LA reservoir into compliance with new regulations.
The project also helps the LAWDP to meet quality mandates set by the United States Environmental Protection Agency (EPA) to ensure that the water is of highest drinking quality.
Council-member Mitchell Englander stated in the news release that "In addition to cutting back on the need to chemically treat our water to prevent natural occurrences like algae, these shade balls are a cost effective way to reduce evaporation each year by nearly 300 million gallons, enough to provide drinking water for 8,100 people for a full year."
The EPA requires LADWP to cover, replace or take offline all of its open-air reservoirs and with the expansive surface of the LA reservoir, it was not practical or possible to use a single floating cover to meet the water quality standards.
Instead of splitting the reservoir in two with a bisecting dam and installing two floating covers that would have cost more than $300 million, LADWP used the 4-inch black plastic balls that cost 36 cents each to meets its regulation standards.
"The shade balls require no construction, parts, labor or maintenance aside from the occasional rotation," the LADWP press release said.
The shade balls are approved for direct contact with drinking water, are BPA free and are expected to last up to 10 years. They can also reduce evaporation off the reservoirs surface by 85 to 90 percent.
Marty Adams, LADWP Senior Assistant General Manager of the Water System, stated in the news release that "not only do the balls protect the water and reduce evaporation losses, but they have also allowed us to virtually eliminate the need to add disinfecting chemicals directly into the LA Reservoir, saving approximately $28,000 each month in chlorine costs and reducing the amount of chemicals needed on hand."
LADWP has been using the shade balls in open-air reservoirs since 2008 to block sunlight, prevent chemical reactions and curtail algae blooms. They are currently being used at Upper Stone, Elysiand and Ivanhoe reservoirs in California.
The LA Reservoir is located in LADWP's Van Norman Complex in Sylmar, Los Angeles, California, and holds 3.3 billion gallons, enough to supply the entire city of Los Angeles for up to three weeks.