A Wireless, Near Real-Time Dry Weather Alert System Under Conditions of Unreliable Data Transmission

In order to monitor compliance with its consent decree, level sensors (pressure transducers and ultra sonics) at combined sewer overflows (CSOs) around the Cincinnati metropolitan area provide level data to a central server over a cellular network and send alarms when programmed thresholds are exceeded. In order to distinguish dry from wet weather events, a near real-time dry weather alert system has been implemented by integrating continuously uploaded rain radar data for the entire county, aggregated by sewershed (see figure), with decision support logic. The decision support logic assesses current rainfall as well as past response and the geographic distribution of rain among other considerations to minimize the occurrence of false dry weather alarms under conditions of unreliable data transfer and complex sewer response. This dry weather alert system, comprising level sensors, radar rain data, and some basic decision logic reduces the number of alarms that human operators must process to virtually none.