Chicago, Illinois (WiredPRNews.com) –Chicago is looking to ‘go green’ in a project that mixes nature and technology in a city project called Green Alleys.
CNN reported that the Green Alleys project in Chicago is a true example of environment-friendly engineering. The aim of the project is to stop polluted rainwater in the alleyways of the city from funneling into the adjacent Michigan Lake. The 13,000 alleys in Chicago that allow access to buildings were built in the 1800s and spread over 1,900 miles.The back alleys provide access to loading, parking and garbage collection. These alleys also make up around 3,500 acres of impermeable surface that has given rise to a serious problem.
Most of these alleys were constructed without connecting them to the storm sewers; as a result, the rainwater puddles collect over the pavement and run into the buildings, sometimes even flooding the basements. The sustainability coordinator of the Chicago Transportation Department, Janet Attarian said, “We wanted to come up with a different way of solving that problem other than reconstructing, putting in a sewer system and adding water to our already full sewer system.”
Concrete, paving stones and asphalt are being used to resurface the alleys as these materials are permeable and water can run through them. Microbes that prosper on oils and fertilizers are seeded to the pavements or they naturally migrate there. These help in cleansing the water from lawns and cars of the pollutants. The clean water goes into ground water and flows into the Lake Michigan.
Attarian said that about a billion gallons of water is taken out of the lake every year and only one percent goes back into it. So, infiltration of the rainwater can help in sending a large percentage of water back to the lake. In addition to that, the Green Alleys pavements have the ability of reflecting light as the surface is light in color so it reflects more sunlight and absorbs less.
In the Green Alley project, recycled materials are used to make the pavements and the light fixtures energy-efficient enabling it them to direct the light downwards reducing light pollution. Until now, 40 alleys have been “greened” and 48 are scheduled to be treated this year.