Today I was watching this video ( http://www.youtube.com/watch?v=2hsGb1SXLuc ) and then panicked!
I've been watering my garden all spring and summer with the garden hose - of course hooked up to the chlorinated city water. Then I started searching and found this: http://www.ext.colostate.edu/ptlk/1548.html.
So maybe there's nothing to worry about, other than the top inch or so? But I think it's time to start storing water in little buckets or a big barrel and then using the water the next day for the watering. I feel, more educated but a bit silly for not thinking of it before, too. Even when I change the fish tank water I'd let the water sit overnight. That wasn't just to get it up to room temperature, but also to let the chlorine evaporate away, too. I'm going to do the same with the garden water starting as soon as possible. More buckets needed!