The water at the dump is the same as is in the rest of the camp. The difference is in the possibly contaminated hose, from being used to flush/ rinse waste. Thats why the sign 'Not Drinking Water' is there.
If you look closely, in nearly all camps/ states you will see a device on the water riser that looks a lot like a regulator. It is an anti siphon device, AKA backflow preventer that will not allow water in contaminated hoses back into the system.
SD law (44:02:09:10-13) requires these devices on ALL water taps, and a potable supply at the dump cannot be closer than 25' to the dump. If a hose is supplied by the camp it cannot be longer than 15' at either the dump or the potable supply.
So. Next time tou see a gadget on the hose bib, know it is not a regulator the last camper left behind, it is a health safety device to protect the water supply.
Noone can do anything about stupid, when you see it, but education of facility is a topic easily broached with the proper manners.
I worry more about those who take the BF preventers assuming they are regulators.