San Francisco shares one nasty thing in common with New York, Chicago and Milwaukee. When big storms soak each city, millions of gallons of stormwater and raw sewage pour into nearby waterways.
It’s a legacy of how the cities were built over a century ago. Sewage and stormwater flow through the same pipes, and during large storms, the combined systems overflow, spilling into rivers, lakes and oceans. The federal government has mandated that the four cities clean up the water pollution.
This article from KQED in San Francisco looks at what San Francisco can learn from other cities, including Milwaukee, where the Milwaukee Metropolitan Sewerage District has implemented a series of Deep Tunnels and a broad green infrastructure program.