Chicago’s Sewer Woes Highlight a Serious Great Lakes Problem

Sewer overflows like this one near Chicago are common in the Great Lakes. (Alliance for the Great Lakes photo)

Chicago may be the new poster child for failing sewer systems in the Great Lakes basin.

The Chicago Tribune reported this week that the city’s Deep Tunnel System, a $3 billion project that was supposed to halt the discharge of untreated sewage into Lake Michigan, has failed to do the job.

Between 2007 and 2010, Chicago dumped nearly 19 BILLION gallons of untreated sewage mixed with storm water into Lake Michigan. The lake happens to be the source of drinking water for 7 million people in the greater Chicago area.


The problem is that Chicago, like many other Great Lakes cities, captures rainwater and sanitary sewage in combined sewer pipes.

When it rains, the resulting stormwater can overwhelm sewage treatment facilities. Cities respond by dumping the bacteria-laden mix of stormwater and untreated sewage into the nearest surface water to prevent the filth from backing up in basements and flooding streets.

These combined sewer overflows, known as CSOs, are a threat to human health and a blatant violation of the Federal Clean Water Act.

Sadly, they are also quite common.

A 2010 National Wildlife Federation study found that Great Lakes cities discharged 41 billion gallons of untreated sewage and storm water into the lakes in 2009 (Chicago and Detroit were among the worst offenders). That volume equals the amount of water that flows over Niagara Falls over the course of 18 hours.

Federal officials are now investigating Chicago’s repeated sewer overflows.

The focus on Chicago’s sewer overflows comes as President Obama and Congress are considering deep funding cuts to the Great Lakes Restoration Initiative. The initiative is part of a burgeoning effort to restore the lakes, a magnificent natural resource that contains 20 percent of all surface freshwater on the planet.

Cutting funding for the GLRI at a time when Chicago and other cities need federal help to upgrade inadequate sewer systems makes no sense.

How can we expect to restore the Great Lakes if the cities that line their shores continue to use these wondrous lakes as sewers every time it rains hard?