Los Angeles was in the news last week when Mayor Eric Garcetti and Department of Water officials used 96 million "shade balls" costing about $34.5 million in the city's 175-acre Van Norman Complex reservoir in the Sylmar section.
Garcetti was of the opinion that the balls would create a surface layer that would block 300 million gallons from evaporating amid the state's crippling drought and save taxpayers $250 million.
But experts have various views on the subject.
"Black spheres resting in the hot sun will form a thermal blanket speeding evaporation as well as providing a huge amount of new surface area for the hot water to breed bacteria. Disaster. It's going to be a bacterial nightmare," said Matt MacLeod, founder of the California biotech firm Modern Moon Farms, Fox News reported.
"This is a blend of how engineering really meets common sense. We saved a lot of money, we did all the right things," said LADWP General Manager Marcie Edwards, according to ABC13.
Biologist Nathan Krekula, a professor of health science at Bryant & Stratton College in Milwaukee, said black balls will absorb heat, transfer it to the water and cause evaporation. "Bacteria required a few things to grow a dark, warm and moist environment. The balls will give them the perfect environment to live in. What works in backyard fish pond does not always transfer to large scale system such as this. Keeping the balls clean when covered in bacteria and mold slime will be a monumental task," Krekula said, according to The World 247.
Meanwhile Dennis Santiago, a risk analyst for Torrance-based Total Bank Solutions, feels that the real purpose behind the black-ball cover is to avoid steep Environmental Protection Agency fines. "This is not about evaporation. The water savings spin is purely political. What the black balls are really about is that [Los Angeles] needs to stay in-compliance with an EPA requirement to place a physical cover over potable water reservoirs," Santiago said.
