I recall attending a brief but informative seminar of worms and worm-farming in Perth some years ago. The main new idea I came away with was the fact that earthworms are lead to their food sources primarily by soil microbes. This inter-relationship fascinated me.
Then, more recently I made the connection between watering the garden with tap water (chlorinated water) as opposed to rainwater. If a garden is watered using chlorinated water it stands to reason that some percentage of soil microbes would be lost through contact with the chlorine. Worms don’t seem to be affected as much as I get a visual on their presence quite often, but microbes are too small.
In my garden it is watered from grey water which is for all intents and purposed recycled tap water. It would be interesting to know whether some of this chlorine ( and what about fluorine? ) is broken down as it is used (clothes washing, dishwashing etc).