What this really ignores is all the inland cities that use the same water source, one down-stream from the next, from the great lakes to the gulf of Mexico. I toured one of those sewage treatment plants in 1993 (1). It remains one of the most beautiful visions of my life: clear water flowing over algea-covered wooden beams, glowing in the natural sunlight, no odor whatsoever.

You can't make this stuff up. Civil engineers are amazing.

Edit: also, as per my other comment, urine, in the voided stream, is not sterile, and even if it were, certainly contains all the building blocks for bacterial growth.

(1) https://encrypted.google.com/maps/place/Johnson+County+Waste...