With approximately 1,900 miles of public alleys, Chicago has one of the most extensive and important pieces of infrastructure of any city in the world. That’s approximately 3,500 acres of paved impermeable surface that provides an opportunity to better manage resources and improve the environment.

Chicago’s Green Alley Handbook, 2010 | Chicago.gov

Chicago’s Green Alley Handbook

PFAS, per- and polyfluoroalkyl substances, are a group of man-made chemicals that includes PFOA, PFOS, and others. PFAS have been around since the 1940’s. They can be found (unnaturally) in food, commercial household products, workplaces, drinking water, and any living organism.

EPA.gov

What are PFAS?