One day in July 2007, Katie Coleman found herself upside down in the Chicago River. Her kayak had hit a submerged tree stump and flipped.

Coleman, 26, a grant writer for the Environmental Law and Policy Center, spent 15 minutes in the water pushing herself out of her craft, righting it and then reboarding.  It was several hours before she showered.

She called in sick to work the next morning with gastrointestinal problems, she says.

Coleman and other environmental advocates say incidents like that illustrate problems with water quality caused by the Metropolitan Water Reclamation District of Greater Chicago. It’s one of the country’s few large sewage authorities that does not disinfect the effluent it pumps into waterways.

The MWRD faces increasing pressure from environmental advocates, and from state regulators, to begin doing so.  They say the district is required to disinfect under the federal Clean Water Act of 1972, which was designed to support healthy fish and wildlife populations and recreation on the nation’s waterways.

“We feel that it’s necessary to protect people that are recreating in the water, which has increased quite a bit over the last 30 years,” says Scott Twait, an engineer with the Illinois Environmental Protection Agency’s Bureau of Water.

District officials say installing and operating disinfection equipment would cost nearly $1 billion over 20 years. Further, they say, there’s no proof disinfection will cut illnesses among people exposed to river water.

The district is conducting studies on the benefits of disinfection, as well as the feasibility of installing the technology.

 “All of these studies need to be generated and complete before we feel comfortable as a technical organization that we are in making a decision,” says Thomas Granato, an MWRD assistant director.  “We have billions of dollars at stake.”

To proponents of disinfection, the measure is a matter of basic public health and safety.

Although all MWRD plants remove pollutants from sewage, the effluent may still contain bacteria and other microorganisms that can cause disease.

Disinfection by chlorination or UV irradiation reduces bacteria, viruses and parasites.

It’s viewed as  “standard” for publicly owned wastewater plants, says Dale Kemery, press officer for the U.S. Environmental Protection Agency.

“Most publicly owned treatment plants do disinfect their effluent,” he says.

Sewerage districts in the nation’s two other most populous metropolitan areas, New York City and Los Angeles, have been disinfecting their effluent for the past several decades.

 The 14 plants operated by the Department of Environment in New York City serve eight million people and treat 1.3 billion gallons of water per day, a volume roughly equivalent to the 1.5 billion gallon flow that the MWRD cleans every day.

Even if disinfection were not required by state regulators, DEP Assistant Commissioner Vincent Sapienza says he’d still recommend it, as a matter of public health and safety for the New Yorkers. Many city residents swim at the city’s beaches and come into contact with treated water.

The MWRD’s disinfection issue hinges on how the Chicago River is classified under the Clean Water Act.  Some waterways will never meet what are known as the “fishable, swimmable” goals of the federal law. They are allowed to meet lower water quality standards.

That’s the situation for the Chicago River. Its heavy waste load and physical modifications -- 57 of the 78 miles controlled by the district are man-made --  exempt it from the highest Clean Water Act standards.

But state regulators are seeking to reclassify the river as suitable for incidental contact, including fishing, boating and wading.  That change would require the MWRD to begin disinfecting the effluent that it discharges into the river at the Calumet, Stickney, and Northside reclamation plants, from March through November.

The Illinois EPA recommended disinfection after conducting a five-year study to review existing and potential uses of the river.  The study found more people than ever are using the river for recreation.

The river’s status has changed dramatically since it served as an open sewer for the city’s waste in the 19th century.

In the 1980s, the district made major progress on its Tunnel and Reservoir Project, designed to combat water pollution and flooding.  TARP’s 109 miles of deep tunnels direct sewage and storm water run-off into reservoirs, where they are held for treatment and release into the river.

The engineering feat keeps billions of gallons of diluted sewage out of the river system and has contributed to a resurgence of herons, egrets, river otters, and up to  70 species of fish.

In  2005, the city endorsed disinfection as necessary for achieving an ambitious agenda of recreational amenities, habitat improvements and improved public access points, including boat launches and the Chicago River Walk, a downtown path along the main branch.

Even so, MWRD officials say disinfection doesn’t necessarily make sense given the river’s main uses.

“We need to remember that this river was primarily designed for treating wastewater effluent, draining urban stormwater runoff and supporting commercial navigation,” says District General Superintendent Richard Lanyon.

Lanyon also says the district is demonstrating leadership by determining scientifically whether the public health impact justifies a massive expenditure of public funds.

 “We don’t know if people are getting sick by coming in contact with this water, or how they’re getting sick,” says Lanyon. “If you don’t know, how can you say that spending a lot of money to provide bacterial treatment is going to provide a benefit? “

According to Lanyon, disinfecting will strain funds already committed to completing two TARP reservoirs and upgrading aging treatment plants.

He calls the disinfection plan “premature” until the 2010 completion of an epidemiologic study being conducted by the UIC School of Public Health.

The study will assess health risks for participants in recreational activities that involve limited water contact, such as boating and fishing. Results could be used to set bacterial water quality standards for the river.

It’s necessary, say district officials, because the federal EPA doesn’t have a bacterial standard for waters designated as suitable for incidental contact.

Many environmental groups, however, don’t consider the study a prerequisite to the new regulation.

“There are very severe limits to what one can show with an epidemiological study …it’s very hard to demonstrate, that because somebody used the waterway and didn’t get sick that that shows that the water is safe,” says Ann Alexander, senior attorney with the Natural Resources Defense Council.

Proponents of the recommendations note that it’s been almost 30 years since the IEPA thoroughly reviewed uses and water quality criteria in the Chicago River.

If disinfection is nixed now, they say, it could be another 30 years before the issue reappears.

“We have a once-in-a generation opportunity right now,” says Margaret Frisbie, executive director of the Friends of the Chicago River.

The Illinois Pollution Control Board, the agency charged with adopting the state’s environmental regulations, continues to hear testimony on both sides in hearings that began in January 2007. Hearings resume with witnesses for the district on Oct. 27 and Oct. 28 at the Will County Courthouse in Joliet.