DWP worker Manuel Martinez waits for the signal to empty out bales of black balls into the Ivanhoe Reservoir in Los Angeles. The Department of Water and Power released about 400,000 4-inch black plastic balls as the first installment of approximately 3 million balls that will form a floating cover over the reservoir. (Irfan Khan / Los Angeles Times)
The work of creating a floating cover for Ivanhoe Reservoir gets rolling. The black balls are designed to prevent the formation of harmful bromate in the water. (Irfan Khan / Los Angeles Times)
The Department of Water and Power’s plastic balls are 4 inches in diameter. About 3 million will be used to cover Ivanhoe Reservoir. (Irfan Khan / Los Angeles Times)
DWP workers empty bales of thousands of plastic balls into Ivanhoe Reservoir . Some residents are concerned about the appearance of the floating covering. (Irfan Khan / Los Angeles Times)
DWP security Sgt. Chris Schnyer looks over Ivanhoe Reservoir partially covered by plastic balls. (Irfan Khan / Los Angeles Times)
