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Chicago, the largest urban area on the lakes,
lies on the southwestern edge of Lake Michigan, the
second largest of the great lakes. The most important river system is the Chicago
River, but the Calumet River
runs through the city as well. The Des Plaines River to
the northwest also plays a major role in Chicago’s
wastewater management. The Chicago Sanitary and Ship Canal carries Chicago’s
treated sewage to the Des Plaines River, where it goes on to the Illinois
River, then the Mississippi River. Chicago
sits on the continental divide between the Mississippi River
and Great Lakes watersheds. Because of this, the Chicago
Sanitary and Ship Canal was constructed to redirect the flow of water away from
Lake Michigan and towards the Mississippi
River. Chicago’s main
source of municipal water is Lake Michigan, so there
were a series of cholera and typhoid outbreaks due to unsanitary water from the
1850’s until 1900 when the canal was completed.
Chicago’s
sewer system was one of the first comprehensive combined sewer systems to be
constructed in the United States
along with Brooklyn in the late 1850’s (Burian et al,
43). The construction of this sewer system was a phenomenal feat because of the
topography of Chicago: “Chicago’s
topography, being unusually flat, was unfavorable to sewer construction…In
reality, the task on constructing underground sewers required raising the city”
(Cain, 360). Thus, in the late 1850’s, the city of Chicago
was literally “raised” a few feet to accommodate the new sewer system.
Sewage treatment
plants were constructed in Chicago
in the early 1900’s, but prior to this the combined sewage had flowed directly
into the surrounding waterways (IDNR). The diversion of the Chicago
River via the construction of the Sanitary and Ship Canal stopped
the dumping of sewage into Lake Michigan, but the rivers
were still receiving heavy loads of pollutants (IDNR). By the 1950’s, however,
the Sanitary District’s treatment plants “could capture and treat about a
billion gallons per day” (IDNR).
Dealing with Sewer Overflows
Chicago’s
sewer treatment system was originally designed to treat about 2 billion gallons
of wastewater per day, but it “may be inundated with more than 5 billion
gallons of rainwater runoff (about 1" of rain) during a single rainstorm”
(TARP). This resulted in many sewer overflows until a solution was found in the
1970’s. Engineers came up with a plan that “selected as best and most
cost-effective was the Tunnel and Reservoir Plan — or TARP. Under this plan,
109 miles of huge underground tunnels would be burrowed under the city to
intercept combined sewer overflow and convey it to large storage reservoirs.
After the storm had subsided, the overflow could then be conveyed to treatment
plants for cleaning before going to a waterway” (TARP). The first stages of
this grand plan were put into service in 1985, and it was immediately heralded
as a huge success (TARP). Now over 20 years later, there have been significant
improvements in the water quality of the Chicago River,
the Calumet River,
and other waterways in the area (TARP). Furthermore, the project “was named by
the USEPA as one of the nation's top Clean Water Act success stories, and is
serving as a model urban water management tool worldwide” (TARP).
TARP
was certainly an effective method to mitigate dumping of raw sewage into Chicago’s
waterways. However, despite the gleaning reports from its advocates, greater Chicago
still dumps huge amounts of wastewater in overflows every year. For instance,
in 2004 alone, the greater Chicago
area dumped over 1 billion gallons of untreated combined sewage in 15 separate
overflow events (MWRDGC PS Activity). The year 2005 was slightly better, with
just over 700 million gallons dumped in just 4 overflow events (MWRDGC PS
Activity). While Chicago’s
discharged waste no longer flows directly into Lake Michigan,
it does flow down the (redirected) Chicago River, to the
Illinois, Des
Plaines, and Mississippi
Rivers, causing equal if not
greater devastation.
Today
Chicago’s wastewater treatment is
somewhat decentralized, using a system of seven different wastewater treatment
plants (MWRDGC Facilities). These seven plants have the capacity to treat
billions of gallons of wastewater every day, and serve an area of hundreds of
square kilometers and millions of people (MWRDGC Facilities). However, in times
of heavy rain or snowmelt, Chicago’s
vast sewerage system can still be overwhelmed, as we have seen evidence of.
Just
because Chicago’s wastewater does
not enter Lake Michigan does not mean that the lake
water and beaches near and around Chicago
are clean or safe. Chicago’s
sanitation problems are compounded by the natural flow of currents within Lake
Michigan. The wastewater dumped by the city of Milwaukee
(which DOES flow into Lake Michigan) occasionally finds
its way down south to Chicago. A
number of lawsuits in the past few decades have held Milwaukee
responsible for polluting waters which eventually reach Chicago.
A lawsuit from 1977 first forced Milwaukee
to begin investing in a new system to mitigate sewer overflows, when “a federal
judge ruled that Milwaukee was
potentially harming Illinois
residents by routinely dumping untreated sewage into Lake Michigan
(Rohde). However, more recent lawsuits, particularly one in 2004, have
dismissed claims by the city of Chicago
that Milwaukee’s overflow events
are causing beach closings in the Chicago
area (Alliance).
Citizen Environmental Action:
There
are many citizen based groups working for the protection of Chicago’s
lakes and waterways. These include: the Friends of the Chicago River,
the Nature Conservancy – Great Lakes Office, the Great Lakes Water Quality
Network, and the Alliance for the Great
Lakes.
Recently,
the Alliance for the Great
Lakes led an effort to push the Bush administration to drop its
proposed federal sewage policy. This policy “would permit sewage treatment
plants to divert sewage around secondary treatment operations anytime it rains,
allowing largely untreated sewage to ‘blend’ with fully treated wastewater
before discharge to waterways” (Alliance). Treatment plants are already allowed
to divert sewage, but only under extreme circumstances. According to the
citizen groups involved, the proposed policy “the proposed policy would provide
a disincentive for treatment plants to upgrade their facilities and make
necessary repairs” (Alliance). The Alliance
for the Great Lakes organizes citizen groups to form a
strong front in fights such as this one. The citizen groups were eventually
victorious, when the proposed plan was thrown out by congress “in the face of
98,000 public comments” (FMR 1).
The
Alliance also provides citizens
with information regarding water quality and news of overflow activity and
environmental risks. Furthermore, it provides citizens with information and
resources required to make a difference. It gives addresses and dates of public
hearings, phone numbers, addresses to send letters, and email addresses to
which comments can be made. It provides opportunities for volunteering and
citizen action such as an “Adopt-a-beach” program. Finally, it partners up with
local Chicago businesses (like
Shaw’s Crab House) as well as international businesses (like Patagonia)
to build support both in and out of the community.
Downtown Chicago, Illinois from the air. (http://rst.gsfc.nasa.gov/Sect6/chicago2.jpg)
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Satellite image of Chicago
Downtown Chicago from Lake Michigan
(http://www.terragalleria.com/america/
mid-west/illinois/picture.usil6675.html)
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