following up on this story...there are voices predicting these spheres will be a natural breeding ground for bacteria. will this be a multimillion dollar boondoggle? I'm not sure but I wouldn't be a supporter at this point
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 water is treated to control algae and bacteria.