Never Drink Downstream From …

Native Americans (aka "Indians") supposedly had a saying: Never drink downstream from a white man.

Why would they say that?

Link: Atlanta Journal Constitution |

The Chattahoochee River is Georgia’s most heavily used waterway. It supplies 70 percent of metro Atlanta’s drinking water, or 300 million gallons per day.

Metro Atlanta’s sewage treatment plants legally discharge more than 250 million gallons of treated wastewater into the Chattahoochee daily. In addition, storm runoff and leaking, broken and overflowing sewers add millions of gallons of polluted water to the river when it rains.