Before revision: Combined sewer overflows (CSOs) Combined sewer outflow into the Anacostia River in Washington, D.C. These relief structures, called "storm-water regulators" (in American English - or "combined sewer overflows" in British English) are constructed in combined sewer systems to divert flows in excess of the peak design flow of the sewage treatment plant.
After revision: Ratcliff Beach CSO discharges into the River Thames in LondonCombined sewer overflows (CSOs) Combined sewer outflow into the Anacostia River in Washington, D.C. These relief structures, called "storm-water regulators" (in American English - or "combined sewer overflows" in British English) are constructed in combined sewer systems to divert flows in excess of the peak design flow of the sewage treatment plant.