What is a Combined Sewer Overflow (CSO)?
Like many older cities throughout the Eastern U.S., Richmond’s sewer pipes carry a combination of sewage from homes and businesses and rainwater runoff to the city’s Wastewater Treatment Plant. That works just fine in dry weather, but when heavy rains come, to keep the sudden onslaught of water and sewage from backing up into homes, it is necessary to release some of the combined sewage into local waterways. This release is called a Combined Sewer Overflow, or CSO.
