Sewer Overflows: Heavy Rain, Old Pipes, More People Make A 'Perfect Storm'

New York City is not alone. Older communities across the U.S. sit atop aging combined sewer and stormwater systems, and are subject to increasingly frequent extreme rain events that come with the changing climate.

http://www.huffingtonpost.com/2011/08/08/rain-sewer-oveflows-dirty-water_n_920940.html