High rainfall over the last several weeks has caused the Metropolitan Water Reclamation District (MWRD) to pour untreated sewage into the Lake Michigan, further causing a shutdown of Gillson Swimming Beach on Memorial Day.
Per the MWRD, on May 29, floodwater from the Combined Sewer Overflow was discharged into Lake Michigan. Another possible overflow was recorded this moring June 1 and a previous possible overflow was recorded on May 26. The Wilmette Park District confirmed that high bacteria count was the cause of the Memorial Day shutdown of the Swimming Beach.
The MWRD has not released an indication of the volume of sewage allowed into the lake, nor has the bacteria count been provided to the public. The Illinois Department of Public Health has not updated bacteria counts on their website since September of 2010.