In 1900, Chicago engineers reversed the flow of an entire river to push the city's sewage away from Lake Michigan; 126 years later, the river still runs backwards

• Chicago's founding problem had always been plumbing.
• The city drew its drinking water from Lake Michigan and emptied sewers into the Chicago River, which flowed straight into Lake Michigan.
• But every rainstorm flushed the stockyards and slaughterhouses and a million people's waste out toward the water intakes.