Are firefighter helicopters allowed to take water from anyone's pool?

YES if they are trying to save homes in neighborhoods they can take water from anywhere they need to or the closest source to the fire and you should be very thankful for that.

It depends. I'm guessing that if the governor has declared a state of emergency then yes. Otherwise, no. But regardless, if there's a fire bearing down on your house are you entirely certain you want to get legal with people who are trying to save your house?

I don't know, I don't think it be a good idea though because the chemicals in the pool is probably not healthy for whatever they're dumping it on

Yes and be careful, if you are drinking water out of a glass and they see that, they can legally scoop that up too. So dont drink outside

Male is correct. i saw it in our own neighborhood.