Is California still experimenting with those "shade balls?"
I think I read that there's some reservoir, maybe near L.A., that's so massive, a liner is ~10x more costly than filling the surface with floating black balls. I also recall something about natural bromine in the reservoir and concerns that it might react in the presence of sunlight and chlorine additives to form bromate, which is unhealthy. I'm not sure if I remembered that correctly, but if I am close it'd be cool if a resident chemist (@Cincydawg?) could detail the mechanism.