31-Oct-16 – After studying the tiniest of life for a few years, scientists say the Chicago River and other Chicago area waterways have a “healthy, diverse microbial community.”

Metropolitan Water Reclamation District of Greater Chicago and Argonne National Laboratory are about half-way through a seven-year study of the waterways. So far, they are seeing “generally stable” communities of micro-organisms such as bacteria. E. coli, for example, which can cause food poisoning, is present but harmless.

Microbial communities are “key players,” says MWRD, in maintaining the health of the Chicago Area Waterway System, which includes branches of the Chicago and Calumet Rivers.

MWRD President Mariyana Spyropoulos says the study will “tell us more about the quality of this improving water.”

“The river has become substantially cleaner over the past several decades, thanks to many interventions, but we still don’t have a very thorough understanding of what lives there,” says Dr. Jack Gilbert (left), an Argonne environmental microbiologist.

Samples are taken every month, March through November, from 16 locations. DNA in the samples is analyzed and microbes are identified and counted.

The report provides a baseline assessment of microbial communities before disinfection. The full study will be completed in 2019.