The water near graveyards can be quite contaminated. I guess drinking it might "heal the community from the burden of an unpleasant member", so to speak.
I read somewhere, that there have been cases of people doing laundry downstream of graveyards, because the water cleaned the textiles unusually well -- this being due to the corpse wax, or adipocere, which has soap-like properties, was getting into the water. Can't seem to find the article, but here's wikipedia: