Smoke from wildfires is covering much of the United States and Canada, according to NOAA satellite data. Wildfire smoke, even at low concentrations, can be a health hazard.
Shade balls are the chosen answer to several problems faced by the Los Angeles Department of Water and Power with their open air reservoirs in the area. The EPA has mandated that such reservoirs be covered. Sunlight has been causing a reaction turning bromide in the water into bromate. a suspected cancer causing chemical. And, in the wake of multiple years of severe drought, open air reservoirs lose millions of gallons of water to evaporation.