An In-stream Smart Illicit Discharge Detection System

Illicit discharges of sanitary sewers into storm sewer systems are one of the problems facing surface water resources due to urbanization. The US EPA estimated the number of cases of sanitary sewer overflow in the United States is 23,000 - 75,000 cases each year. The typical protocol for identifying illicit discharge events relies heavily on citizen reporting and quarterly or biannual in-stream sampling by local water municipalities. This protocol does not provide enough temporal resolution to promptly identify and address problems relating to the sewer overflow. In some cases, the sewer overflow goes undetected for days, sometimes weeks. A continuous monitoring station was designed using cost-efficient sensors to the relevant collect data, filling in the temporal gaps between scheduled in-stream sampling interval. The monitoring system captures pH, conductivity, dissolved oxygen, and temperature every 10 minutes. Data logged from the station is sent wirelessly to a server for storage, display, and processing. The advantages and disadvantages of the system will be discussed. The continuous monitoring station showed potential as a smart continuous monitoring system to promptly capture illicit discharge events.