You know how wine is made? Well, they mix the ingredients and let it age in a keg for several decades. Imagine feces mixing with water and being stored like wine until it's ~50 years old. That's what the water in Louisiana tastes like.
One time, I was on a cruise, and they used charcoal filters for the sinks. It was just my luck that the charcoal filter broke when I used it, spilling black sludge everywhere. 
