Chicago Sanitary Canals, anything but sanitary

by |July 12, 2010

A story by Dan Egan in the Milwaukee Journal Sentinel on July 6, 2010 pulls together threads of sewage, drinking water, commerce, ecosystem deterioration, politics, health, geography, and Asian carp to create a picture of how big a mess we humans are capable of making for ourselves.

Source: Wikimedia

Source: WikimediaTo say a mess might be an understatement.  It begins with Chicago’s decision in 1900 to reverse the flow of the Chicago River so that it flowed not into Lake Michigan, but inland toward the Mississippi river basin.  To accomplish this, they created a system of canals and locks.  Why did they do it?  So that their open sewers wouldn’t flow directly into their drinking water supply.  There is a reason they are called the Chicago Sanitary and Ship Canals.

The article explains, which I hadn’t known despite spending significant time in the Windy City, that Chicago’s sewage treatment system discharges only lightly treated fecal matter into the canals and river.  The city drew water from Lake Michigan to create enough flow in the canals to keep the disgusting sludge moving away from the city, like a great flushing toilet tank.

Egan says, “Chicago has a rare distinction among major American cities: It does not employ a disinfection stage at its three main sewage treatment plants.  The result is a river and canal system running so thick with fecal coliform that signs along the banks warn that the contents below are not suitable for ‘any human body contact.'”

Chicago Sanitary and Ship Canal, Looking east from Pulaski Road, Chicago, IL:

Source: muledriver on Flickr
Source: muledriver on Flickr

As if that weren’t a big enough mess to contemplate, those are the canals that are allowing the Asian Carp to migrate from the Mississippi toward the Great Lakes, as I discussed in a previous blog post.  The dire pollution used to be an effective barrier to the invasive species, but as Chicago has begun to make an effort to treat its sewage more thoroughly (though still not disinfect it), fish, native and foreign, have been moving back into the canal waters.  To replace the sewage barrier, in recent months they have been desperately dumping poison into the water, killing everything in an attempt to keep the Asian Carp out.

Egan says, “The poisoning is part of a $78 million federal emergency plan to buy the Great Lakes some more time. It includes three electric fish barriers in the canal and research into beating back the invaders with bubbles, lights and even noise.”

The Mississippi and Great Lakes are two separate hydrological systems, which have evolved in isolation to each other, so the canals can allow not only the Asian invasive fish into the lakes, but also native ones that simply were not meant to cohabit in that ecosystem.

States bordering on the Great Lakes are clamoring, and suing, to get Illinois to close the canals and locks permanently, cutting off the artificial connection between these two great basins.  But how then would Chicago dispose of its effluent?  And another question, what would it mean for the shipping industry that depends on navigating through the Great Lakes and into the American heartland via those canals?

Lockport Lock:

Source: wikimedia

Source: wikimedia

And if Chicago doesn’t figure out another way to dispose of its sewage, what will the city drink?  They have been limited by the Supreme Court to taking 2.1 billion gallons of water per day from the lake – which must be split between consumption and the Big Flush.

Egan quotes Josh Ellis, from the nonprofit Metropolitan Planning Council, “Over the next 100 years Chicago will be at a disadvantage in terms of water supply,” says Ellis. “And I think that’s the real reason to build a separation – it’s about the water.”

A very big mess indeed, and one that will require a lot of ingenuity and money to fix.

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LCurtJulia Apland HitzE. RothenbergSabi Recent comment authors
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Wow, I had no idea! Thanks for the enlightening (albeit disgusting) insight into the Windy City’s water problems!

I guess it just highlights that we’re wrong if we think very serious water problems are something that affects only the developing world.



I appreciate you writing about this story. I’ve lived in Chicago most of my life, including currently, and the news coverage on the asian carp and fish kills does not cover the entire history.

Do you know of anything responsible Chicagoans could do to help this situation?

E. Rothenberg
E. Rothenberg

I just want to clarify, as a former Chicago resident (and native), that the reversal took effect in 1900, not “1990” — I believe that was a typo in this article. Ironically, it was in 1990 that Mayor Daley begin efforts to clean up the river to a usable status. It is much less disgusting than it used to be in terms of garbage and industrial pollutants. That said, it is true that we flush our waste down the Mississippi like a giant, public toilet (why not send it towards the poor people of the South, of course?) What’s more,… Read more »


The other day me and a brother Vietnam . Went to the canal trying a new fad using magnets to recover metal from the waterway around Chicago, How sick never again. They need to post warning signs or don’t they care about the people in the State of I’ll.


Thank you for this informative article. I grew up in Evanston, literally right next to the canal — McDaniel between Davis and Church Streets (black middle class neighborhood). When I was about eight a kid was walking on the ice, which broke and he was swept away. We did understand there was an undertow but still we played along those banks all the time (a miracle we all survived it). There were no signs and no barriers and nothing to prevent us from falling in at any time. Fortunately, we moved when I was 14 to Glencoe. Of course back… Read more »