Chicago's Back Alleys Filter Rainwater for Lake Michigan

[aaron38]

CHICAGO, Illinois (CNN) -- Environmentally friendly engineering is really right up Chicago's alley -- in a city project called "Green Alleys." The program aims to stop polluted rainwater in the city's alleyways from ending up in adjacent Lake Michigan.
So, the extreme alley makeover started with the pavement. The alleys are being resurfaced with concrete, asphalt, or paving stones that are permeable -- that is, water runs through them like a sieve to the dirt beneath.
Microbes that thrive on stuff like fertilizer and oil are either seeded into the pavement, or they migrate there naturally. They cleanse the water of pollutants that come from cars and lawns. The cleaner water eventually makes its way into the groundwater -- called an aquifer -- and then flows into Lake Michigan.
http://www.cnn.com/2008/TECH/biztech...ete/index.html

I don't know if this is old news, but this was the first I'd heard of this program, which sounds like a damn good idea.