CSO Warnings

Stay in the Know About CSOs

During Combined Sewer Overflows (CSOs), untreated sewage is released into the Illinois River. CSOs occur throughout the year and on average, Peoria experiences between 20 and 30 overflow events per year at 16 locations. CSOs cause elevated bacterial levels in the river exceeding the levels considered safe for contact. Learn more about CSOs.

Stay current on CSOs by signing up for CSO notifications and visiting this page.