MUNDOLIMPIO11

Those are municipal workers in Los Angeles pouring "shade balls" into one of the city's reservoirs. The black plastic balls help maintain water quality by blocking sunlight, thereby preventing hazardous reactions with the chlorine and bromide in the water. (The shade balls also cut down on evaporation, though this is a relatively minor benefit.) Yes, shade balls. Fun to say. Fun to watch. But also surprisingly useful A brief history of shade balls Black plastic shade balls have been used for all sorts of purposes over the years. Catherine Kavanaugh of Plastic News  reports that they've been deployed  to "keep birds out of water near airport runways, control vapors in industrial ammonia tanks, or stop water from evaporating at petroleum operations." And in recent years, the city of Los Angeles has realized that shade balls can be useful for protecting drinking water from contaminants. Back in 2007, the LA Department of Water and Power  discovered i