Development of the real-time control (RTC) system for Tokyo sewage system.

Tokyo Metropolitan government has decided to make the maximum possible use of the existing facilities while ensuring safety against inundation and to promote measures also from a software approach by introducing a system capable of minimizing combined sewer overflow, the real-time control system (RTC). A pilot RTC system was installed in August 2002 for the Shinozaki Pumping Station. The RTC system monitors the precipitation volume and the water level in the pipe. Simulations were carried out on the basis of these data. From the results, it was found that with the use of the RTC it is possible to reduce CSO by roughly 50% for small rainfalls with a total precipitation level of 20 mm or less by strong rainwater in the pipe routes at the beginning of the rain. It has also been shown that CSO can be reduced by about 80% through the use of rainfall forecasting.