A Publication of WTVP

The Illinois River has a rich economic, social and cultural history in the city of Peoria. It provides a water supply for industry, recreational opportunities for boaters and fishermen and an important habitat for fish, waterfowl and other wildlife.

Once virtually abandoned, the Peoria riverfront is being reclaimed and revitalized. Amenities include a visitor’s center, city park, boat landing, restaurants, sports and entertainment venues and retail space, while the proposed Central Illinois Regional Museum and Caterpillar Visitor Center will draw thousands of additional visitors annually. With thousands of visitors each year, the Peoria riverfront requires a river that is a healthy, attractive and sustainable resource.

Despite this progress along its banks, the Illinois River does not meet Clean Water Act goals. According to the Illinois Environmental Protection Agency, swimming, jet skiing and water skiing are not safe due to bacteria contamination. Contributing to bacteria problems are Peoria’s older sewers, which combine stormwater and sanitary sewage in the same pipe—a pipe that can overflow when it’s overwhelmed by incoming rainwater.

The City of Peoria is conducting a required study of the river’s water quality, focusing on the bacteria impacts of sewer overflows. Both the Illinois River and sewer outfalls are being sampled for bacteria (fecal coliform and E. coli), dissolved oxygen, temperature and other parameters. The study, required by the city’s permit with the Illinois EPA, seeks to understand how sewer overflows affect water quality in the river and what can be done to reduce overflows at an affordable cost to Peoria residents and businesses. By December 2008, the city must complete a long-term plan to reduce sewer overflows and meet Clean Water Act requirements.

A Legacy of the Past

Like many other cities, Peoria built storm sewers in the late 1800s and early 1900s to carry rainwater and melting snow away from homes, businesses and streets. In those horse-and-buggy days, cities didn’t have sewage treatment or even indoor plumbing.

Later, when indoor plumbing came, homeowners and business owners hooked their sewage lines to the existing storm sewers, combining storm water and raw sewage into one pipe, a standard practice at the time. With the formation of the Greater Peoria Sewer District in 1929, modern sewage treatment became available to the citizens of Peoria. The existing combined sewers were connected to a large interceptor sewer along the riverfront and sewage flowed to the new treatment plant.

During dry weather, a “combined” sewer system works much like a separate sewer—carrying all sewage to the plant for treatment. When it rains or when snow melts, the sewers can be overloaded with incoming stormwater. In these cases, sewage flows over a dam in the sewers and into the Illinois River without treatment. If sewers did not have this release mechanism, raw sewage would back up into basements and streets.

Today, when building new sewer systems, we build separate sewers for storm- water and sewage. Yet these older, “combined” sewers remain in Peoria and in many older cities throughout the country.

Peoria is Not Alone

According to the U.S. Environmental Protection Agency, 746 communities in the United States have combined sewer systems. Most communities with combined sewer systems are located in the Northeast and Great Lakes regions and in the Pacific Northwest. More than half of them are found in four states: Illinois, Indiana, Ohio and Pennsylvania. Illinois has more than 100 communities with combined sewers. Like Peoria, they are required to develop plans to reduce sewer overflows.

Raw sewage overflows from Peoria’s sewer system in 15 locations along the Illinois River, beginning upstream at Spring Street and ending downstream at Darst Street near the Greater Peoria Sanitary District treatment plant.

During the late 1970s and early 1980s, Peoria built many sewer system improvements that reduced both the frequency and volume of sewer overflows. Today, the sewer system overflows an average of 28 days per year.

Public Input Needed

Because each city’s overflow problem is unique, the Illinois EPA and U.S. EPA encourage public involvement in developing the solution. To help the city sort through the options, we have formed a Clean River Committee that includes representatives from the Chamber of Commerce, the business community, health department, park district, school districts, environmental advocacy groups, government agencies, citizens and Bradley University.

The committee will meet periodically this year and throughout 2008 to advise the city on the alternatives for reducing overflows, reviewing the financial analysis of what we can afford and reaching out to the public. Committee meetings are open to the public and are held at the Greater Peoria Sanitary District offices.

Meetings for the general public will be held next summer to review the options for reducing overflows and their costs and benefits. In the meantime, members of the project team are available to speak to civic groups and organizations about sewer overflows and what might be done to address them.

At this stage of our study, we don’t yet know the full scope of the problem, the long-term options or the costs we may face to meet state and federal requirements. We do know that state and federal funding is very limited, and that ratepayers will be required to foot all or most of the bill. Our goal is to negotiate a long-term plan that is both cost-effective and affordable for Peoria ratepayers.

For more information on sewer overflows, the Clean River Committee and the city’s plans, visit, or call Project Manager Jane Gerdes, P.E., at 494-8819. IBI