Chicago's Deep Tunnel Nears Completion

CHICAGO, Illinois, February 14, 2006 (ENS) - Terrence O'Brien, president of the Board of Commissioners of the Metropolitan Water Reclamation District of Greater Chicago, says with satisfaction that Chicago's Deep Tunnel is nearly finished after 30 years and the expenditure of $3 billion.

O'Brien said, "The Board of Commissioners adopted the Tunnel and Reservoir Plan (TARP) in 1972. After many years of construction, the end is finally in sight. We are extremely pleased with the performance of each section of the tunnel so far, capturing hundreds of billions of gallons of polluted water that used to go directly into the waterways.

Mining work is finished on the 7.9 mile Little Calumet Leg of the Deep Tunnel System, and final connections are scheduled for completion on March 1.

When the Little Calumet leg of the tunnel goes into operation, it will mark the total completion of all 109.4 miles of tunnel included under Phase I of the TARP project, and the culmination of 30 years of tunnel construction.

Stretching beneath Cook County, the tunnel is 15 feet in diameter, lined with concrete and is located at a depth of 150 to 300 feet below ground in limestone rock.


Terrence O'Brien is president of the Board of Commissioners of the Metropolitan Water Reclamation District of Greater Chicago. (Photo courtesy MWRD)
"We're picking up the outflows during a heavy rain event that normally would have flowed into the inland waterway system and polluted that waterway system. Now, we've actually created an underground river to capture that raw sewage and then to run it through the normal treatment like we do on a dry weather day," O'Brien says.

As a result of the Tunnel and Reservoir Plan, fish have returned to the Chicago River, the Calumet River and the Des Plaines River, he says.

Now, residents of the communities of Dixmoor, Riverdale, Harvey, Phoenix, Dolton, South Holland Calumet City and Lansing will benefit because polluted stormwater will go into the tunnel rather than into the Little Calumet River, O'Brien said.

The first of three huge terminal reservoirs - the O'Hare CUP near O'Hare International Airport - was completed in 1998. These reservoirs are a joint project of the Water Reclamation District and the U.S. Army Corps of Engineers.

Eventually, all the captured stormwater will flow by gravity to the Thornton Reservoir, and then will be pumped to the Calumet Water Reclamation Plant for treatment. "Capturing combined sewer overflows will keep the waterways healthy and reduce flooding in the area," O'Brien said.

Funding to complete the plan has been tough to obtain for the past several years. In its most recent budget statement in December, the District says, "Our long-term plans to reduce pollution, flood damage, and associated costs by completing the Tunnel and Reservoir Plan (TARP) hinge on continued funding by the United States Army Corps of Engineers."

The $230 million reservoir in Thornton is under construction, funded by the District to accelerate its completion by 2014.

In 2004, the Board of Commissioners authorized the District to fund the design and construction of the Thornton Composite Reservoir. This authorization was necessary due to concerns over the U.S. Army Corps of Engineers' inability to get adequate funding over the last three years and the continued uncertainty for future funding to complete the reservoir by 2014.


Inside the Chicago Deep Tunnel (Photo courtesy MWRD)
Design work on four projects with a combined value of $144.4 million will be started by the District in 2006 to ensure timely completion of the Thornton reservoir. The District will continue to pursue federal reimbursement for 75 percent of these expenses.

The White House did not request funding for the TARP project in its 2006 budget, and the project's 2006 funding came in at $27.5 million as a result of efforts by the Illinois Congressional Delegation.

The White House Fiscal Year 2007 budget request provides for $45 million in federal construction money for the first 3.5 billion gallon phase of a reservoir in McCook. If the appropriation is approved, construction would start in October.

The reservoirs collect combined stormwater and sewerage collected by the 109 mile long Deep Tunnel until it can be treated and safely released into the region's waterways. This avoids the diversion of fresh water from Lake Michigan to dilute the contaminated water.

When completed, the three reservoirs will increase the capacity of the TARP system by 15.6 billion gallons, providing flood relief benefits and additional pollution control improvements.

The District is a separate government agency - neither a part of the City of Chicago nor the Cook County government. The District collects and treats wastewater from more than five million people in Cook County and the industrial equivalent of another four million people.