"tainted irrigation water"
I have seen lots of that in the U.S. It is "treated" water from the sewage treatment plants and pumped to irrigation systems. Where I used to live in FL, that is what they used to keep the golf course nice and green. I called it natural fertilizer.
If not treated properly, or if there is some real bad nasties in the water, it WILL end up back into the water system. My, how we trust our government.
They are talking about running treated water back to our cooling towers for us to recycle...... I am not looking forward to going into them to clean them out. It is our annual duty during the winter months....