Toxics Release Inventory (TRI) Program
Urban Communities:
Chicago Metropolitan Area
![]() TRI facilities in Chicago Metropolitan Area |
Quick Facts for 2010:
|
The Chicago-Joliet-Naperville, IL-IN-WI metropolitan area is the third largest in the United States with a population of 9.5 million. It includes nine counties in northern Illinois, four counties in northwest Indiana, and one county in southeast Wisconsin. The metropolitan area covers 9,581 square miles on the Chicago Plain, a flat and broad area along the southwestern curve of Lake Michigan. Principle cities in the metropolitan area include: Chicago, IL; Joliet, IL; Naperville, IL; Elgin, IL; Gary, IN; Evanston, IL; Arlington Heights, IL; Schaumburg, IL; Skokie, IL; and Des Plaines, IL.
Lake Michigan is the drinking water source for over five million people in the area. Heavy traffic, industrial pollution and sewage overflows threaten the health of the lake. Air pollutants from industries and power plants are also a pollution source as they are deposited from the atmosphere into the lake. Other important waterways in the metropolitan area include the Chicago River, the Des Plaines River, the Fox Chain O'Lakes, and the Fox River.
The Chicago metropolitan area is one of the major industrial centers in the United States, manufacturing chemicals, petroleum products, machinery, food, steel and other metal products, automobiles and other transportation equipment, printed materials, plastic and rubber products, computers, and telecommunications gear. The area is a major electric power producer with several large electric power plants, many coal-fired. It is also an important transportation hub; the Port of Chicago connects the Great Lakes to the Mississippi River via the Illinois River.
Primary metals facilities (such as iron and steel mills and smelters) had the largest surface water discharges, on-site land disposal or other releases, and on-site underground injection of all sectors in 2010. This sector accounted for more than three-quarters of each type of disposal or other releases listed above in the metropolitan Chicago area. This sector's chemicals with the largest disposal or other releases included nitrate compounds released to water, zinc and manganese and their compounds to on-site landfills and ammonia and phenol in underground injection wells. Electric utilities reported almost 41% of total air releases in the metropolitan Chicago area for 2010. Over half of the air releases from electric utilities was hydrochloric acid.
Total on-site disposal or other releases for the Chicago metropolitan area decreased by 17% from 2001 to 2010 but increased by 9% from 2009 to 2010. Air releases decreased 23% from 2001 to 2010 but increased by 8% from 2009 to 2010. Surface water discharges decreased by 38% from 2001 to 2010 but increased by 22% from 2009 to 2010. The primary metals total on-site disposal or other releases decreased by 10% from 2001 to 2010, but increased by 13% from 2009 to 2010. This sector reported a 39% increase in surface water discharges, a 9% increase in on-site land disposal or other releases and a 4% increase in underground injection from 2009 to 2010. Electric utilities' air releases increased by 72% from 2001 to 2010 including an increase of 8% from 2009 to 2010.
Top Five Chemicals by Environmental Medium
Chicago Metropolitan Area, 2010
These charts represent the top five TRI chemicals in pounds released for this urban community, and do not include all chemicals of concern nor the priority or importance of those chemicals within the urban community.

