Well, here it is. Water ends up back at a plant where all the bits of junk are sieved out, then they add chemicals to kill the bacteria and such. Even if we don't get fish running out of our taps we still recieved the bill that it cost to clean out the water... The more people put stuff down their loos, the more work the water plant laborors have to do, the more you are charged for your water.i dont think water is recycled like that, if what you said is true, i wouldnt be too worried about water with a small dead fish in it because there are things that are worse that go down the toilet.
So I suppose thinking about it fish don't end up back in the system and all their nasites are cleaned up by chemicals... but we end up paying for it after all.