Front and Center: How Chicago's excrement is killing fish in the Gulf of Mexico

June 23, 2011

Produced by Eight Forty-Eight

Download Story
(Getty/Joe Raedle)
WBEZ's Gabriel Spitzer explained how Chicago's waterways affect dead zones.

Water has created prosperity in the Midwest, but it has also unleashed destructive forces. In this installment of Front and Center, WBEZ’s Gabriel Spitzer explained why what we flush is coming back to haunt us. He joined Alison Cuddy from Lacon, Illinois, some 130 miles southwest of Chicago.

The Illinois River is contaminated with heavy amounts of "nutrient pollution," chemicals such as nitrogen and phosphorus are causing problems along waterways from Illinois all the way to Louisiana. 

The chemicals, used commonly in fertilizer, allow algae and water plants to grow at an increased rate. As the aquatic flora bloom and die, the breakdown process sucks up the oxygen in the water, leaving behind "dead water" -- and dead fish.

Although agriculture accounts for the majority of nutrient pollution, Chicago is a major contributor of nutrient pollution in the Illinois River.  In short: Chicago's sewage, by way of the Chicago River, accounts for 3/4 of the phosphorus, according to Professor Mark David of the University of Illinois.  That amounts to about one pound of phosphorus per person, per year, in the Chicago area with a population of close to six million.

Even worse, the phosphorus is channeled from the Chicago River, through the Illinois River into the Mississippi River -- eventually ending up in the Gulf of Mexico.  The abundance creates a so-called "dead zone," where countless fish are killed at the mouth of the Mississippi River. This year's dead zone is anticipated to be the size of New Hampshire, the biggest forecast to date.

Although the pollution is mostly agricultural, on the watershed level, Chicago is the single largest contributor to the dead zone, according to the U.S. Geological Survey.  These dead zones are a major unintended consequence of linking the Great Lakes, via Chicago, to the Mississippi River.

The environmental damage is prompting regulators and interested groups to advocate for enhanced measures at wastewater treatment plants to remove the nitrogen and phosphorus. Officials anticipate regulation to curb nutrient levels will cost billions in the Chicago area alone.