水库上漂9600万个黑球是为了什么？

shade ball, 96 million

life vest

they are filled with water, because the strong wind in L.A reservoir can have them bounce on the 5 freeway.

when you disinfect the water with ozone, that bromide溴离子（harmless, almost impossible to move） becomes bromate溴酸根离子（carcinogenic致癌的).

filter plant

within 10 micrograms per liter limit set regulators

bromide with chlorine 氯which is supposed to be safe, in bright sunlight form bromate even more thaan ozone.

tarp防水布

trampoline蹦床 with poly聚 like PVC聚氯乙烯 pipe

high density polyethylene聚乙烯 pipe

carbon black 炭黑（stable)

it will not leach material out, inert惰性的不反应的，food grade

without sunlight

control the algae藻类 growth

put in basically no chlorine

1.exposed surface

2.airflow

3.contain mostly air, a good thermal insulator

reduce evaporation by eighty to ninety percent

three for a dollar

save

hexagonal六边形的 balls