Combined Sewer Overflow (CSO)
A combined sewer is designed to transport both stormwater and sewage in the same pipe. Normally, all of this wastewater and rainwater flows together to a wastewater treatment plant, where it is treated and released back into the environment. However, during times of heavy rainfall or snow melt, the capacity of the combined sewer system may be exceeded, causing untreated wastewater and stormwater to be released into a stream, river, or lake through a combined sewer overflow (CSO).
Many large cities, like Cleveland, still utilize combined sewers that were installed many years ago. When these sewers overflow into our local water bodies, they can cause significant water pollution and lead to beach closings.
For more information:
Ohio Environmental Protection Agency
United States Environmental Protection Agency
Local CSO Notifications
Northeast Ohio Regional Sewer District
City of Lakewood