Many sausages are made with the intestinal linings and viscera of animals who live in, root around in, and occasionally even eat their own feces. Shit that's passed through shit that's passed through shit.
And yet, few people bat an eyelash at hot dogs, brats, or cocktail weenies. Of course, there's that old chestnut about not wanting to know 'how the sausage gets made.' But, by and large, people cognitively distance the making-of-the-sausage from the sausage itself. Why? Because they've been trained to think of "sausage" as a wholly separate class of item from "pig's colon." And because they've first encountered -- and enjoyed -- sausage before anyone ever told them about how it got there.
We need to use similar psychology to fight the psychology of contamination thinking w/r/t treated wastewater. The message needs to be about how the input is apples, and the output is oranges. But we have to start with the oranges. It's very tough to sell the story when the story begins with the making-of-the-sausage and not the sausage itself.