After years of resisting government mandated standards, the Metropolitan Water Reclamation District of Greater Chicago has recently reversed its position by implementing new equipment to better treat the bacteria-laden water it routinely releases directly into the Chicago River. Despite successful efforts to transform the Chicago River into the city’s next great recreational asset, the amount of potentially tainted water that was previously pumped into the river is staggering. In some areas, the discharge of untreated water accounted for as much as 70% of the river's total flow, according to Josh Mogerman of the Natural Resources Defense Council. While the Metropolitan Water Reclamation District first rejected the adoption of new equipment on the grounds of being prohibitively expensive, a change in District leadership plus a 2011 order from the Obama Administration demanding that Chicago comply with nationwide standards saw the agency finally change its tune.

Despite initial complaints, the new technology — which involves the use of ultraviolet light to effectively kill the pathogens that routinely come into contact with the river’s increasing number of recreational users — has actually cost less than original projections. In September the District added the UV equipment to its south side Calumet Water Reclamation Plant and upgraded the north side O’Brien Plant in Skokie just last month. According to the Chicago Tribune, the O‘Brien facility services the Chicago River’s North Branch as well as the North Shore Channel, treating the waste of roughly 1.3 million Cook County residents living between Fullerton Avenue and Lake-Cook Road.

While clear efforts have been made to improve the quality of water flowing from treatment plants, raw sewage still finds its way directly into Chicago’s waterways after heavy summer rains often overwhelm the city’s infrastructure. When rainfall gets particularly bad, the city has no choice but to open the river locks and release the contaminated runoff directly into Lake Michigan — home of Chicago’s beaches and drinking water supply. Officials hope to curb (although not entirely eliminate) the runoff issue with the opening of the first phase of the so-called "Deep Tunnel" project in approximately one year’s time. The $3 billion project will connect to a new reservoir system in suburban McCook, Illinois that can store sewage-tainted stormwater during heavy rainfall for treatment later. The project, which was originally conceived in the 1970s, isn’t expected to be operating at full capacity until 2029. Despite these improvements, much work still needs to be done before the river is even close to being considered safe enough for recreational swimming.

·Chicago River cleanup makes waterway safer for recreation [Chicago Tribune]

·U.S. demands Chicago River cleanup [Chicago Tribune]

·Chicago urban planning archives [Curbed Chicago]