500 fecal coliform bacteria (aka poop, shit, deuce, the brown) per liter of water is said to be safe for swimming. Personally, I prefer there to be no shit in my swimming water but accidents do happen.
100,000 fecal coliform bacteria per liter is the threshold for international recognition (by me) as an official River of Shit.
The Ganges in Varanasi checks in with a whopping 1,500,000 fecal coliform bacteria per liter. We may need to get a fecal coliform expert down here for verification, but I think that means there is more shit in this water than there is water.
Yet people travel to India to bathe in the Gange river.