UPDATED 10/27/11 9:50 a.m.

CHICAGO (CBS) — A new study from the University of Illinois at Chicago has concluded that even though the Chicago River is full of wastewater, it has no greater risk of making people sick than other waterways.

The study, which was funded by the Metropolitan Water Reclamation District of Greater Chicago, concluded that canoeing, kayaking, rowing, boating and fishing on the Chicago River pose the same risk of contracting gastrointestinal illness as performing those activities on other local waters.

LISTEN: WBBM Newsradio’s Lisa Fielding reports

But the study says the risk turns out to be higher than for people who immerse themselves in the water while swimming at Lake Michigan beaches.

Federal regulations protect swimmers at beaches, but not for people who use boats in waterways not approved for swimming, the study said.

Principal investigator Samuel Dorevitch said in a news release that given that sewage discharge makes up most of the contents of the river, “It was a surprise that the occurrence of illness was similar” for limited-contact users of the river compared with other local waterways, the study said.

“What was somewhat surprising is that we found a similar rate (of development) of gastrointestinal illness after using other waters in the area, like the Fox River, the Des Plaines River, the Skokie Lagoons or Lake Michigan beaches,” Doretivch told WBBM Newsradio’s Lisa Fielding.

The rates of infection for the Chicago River were also similar to those for small inland lakes such as Tampier Lake in Palos Township, Busse Woods Lake near Elk Grove Village, and Crystal Lake in the town of the same name.

The U.S. Environmental Protection Agency says beaches are safe to swim at a level of bacteria in which eight people in 1,000 get sick. Dorevitch is not sure why activities that do not involve entering the water exceeded that risk on the Chicago River and the other rivers and inland lakes.

“The fact that 14 people per thousand, instead of eight per thousand, on average, are getting sick due to their use of the water is concerning,” he said. “It means that we may have a higher rate of illness at inland waters than would be acceptable at coastal waters. This raises the question, should the EPA be doing more to protect people in those inland waters?”

In May, the EPA demanded that parts of the river be clean enough for “recreation in and on the water,” which means activities from swimming to canoeing. The order also applies to the Cal-Sag Channel and the Little Calumet River.

Around the same time, the Chicago River also made the “America’s Most Endangered Rivers” list from the conservation group American Rivers, which called the river a “health threat.”

But estimates put the cleanup cost at $425 million, which will likely mean higher sewer bills in Chicago and suburban Cook County, where such bills are among the nation’s lowest, according to published reports.

The Chicago River system runs 156 miles, and is the waterway that first drew explorers to the area. French explorers Louis Jolliet and the Rev. Jacques Marquette explored the Chicago River in 1673, and Jean-Baptiste Point du Sable, the first permanent settler in Chicago, set up his farm on the north banks of the river in the 1780s.

But for longer than anyone has been alive today, the river has been associated with sewage and stink. In 1900, the Sanitary District of Chicago reversed the flow of the Chicago River, after sewage emptying into Lake Michigan from the river’s main branch caused a public health crisis.

For most of the century afterward, the river was widely regarded as dirty and stinky, but beautification efforts have improved some parts of the river in the past 20 years.

Chicago is the only major city in the United States that does not disinfect human and industrial waste in the sewers before it ends up in the waterways, according to published reports.