Have become an active brewer of aerated compost tea for my vegetable garden. Using worm castings, a 5 gallon tub, dual air flow aquarium pump, and added molasses and liquid seaweed.
I typically use pond water as my base as I learned that my chlorinated tap water is going to hinder bacterial growth.
But leads me to a question. When I water my garden from the hose or sprinkler system (both of which come from the tap), am I killing the bacteria in the soil that I'm trying to encourage via the compost tea drenches?
Just seems odd that I'm using such a purist method to make the tea, but that every other day I'm drenching the soil with chlorinated tap water.
I think it depends on how much you water, how (amount of aeration), and which type of chlorination your water company uses (how fast it leaves the water), but yeah, chlorine kills stuff. I'd guess the soil system is more robust than the water-born bacteria the chlorine is designed to protect against, so I'd guess you don't kill the colony. (Maybe just knock off the weak ones.)
If you can use rainwater, that's probably best. They make dechlorinator sprayer end thingies, but I don't have any experience with them.
How serious are you? You could fill barrels and let them sit for a day while the chlorine goes away. Then drop in a simple low end sump pump and water from the barrels. If the need is great enough you could consider drilling a well.
Personally, chlorine from the tap is not that big of a deal. For a time, I would leave out water overnight, then water by hand. Too much work for no noticable difference. Never lost a plant from watering directly with the hose.
Rain and well water can easily have as much or more toxic chemicals in it. Rain is formed around dust particles in the air, including exhaust from cars and factories. Ground water often has unsafe concentrations of agrochemicals. That's why many municipalities have switched to surface water over the last decade.
That being said, if you have healthy soil, small amounts of toxins or chlorine will not be a problem. Soil microbes are pretty adept at breaking them down.