Entry: Combined Sewer and Overflow (CSO) originally posted by xrahy
Combined Sewer Overflows (CSO): A combined sewer is a sewer that is designed to carry both sanitary sewage and storm water runoff. A discharge from a combined sewer system occurs during rainfall and/or snowmelt because the carrying capacity of the sewer system is exceeded. Both the combined sewer overflow structure and the discharge from the structure are referred to as "CSOs". High potential for dangerous sewer gases and other health hazards.