Digital Detection for MS4 Program Efficiency: Leveraging Dollars and Data

As a component of the Louisville Metropolitan Sewer District's (MSD) Municipal Separate Storm Sewer System (MS4) permit, illicit discharges are to be detected and eliminated in a variety of ways. Water quality is severely impacted because of illicit discharges to Waters of the United States. MSD has utilized aerial imagery datasets to produce faster, and more cost-efficient analyses to meet permit requirements. Specifically, two MS4 minimum control measures benefit from the incorporation of Geographic Information Science (GIS) data: Total Maximum Daily Load (TMDL) monitoring and Illicit Discharge Detection and Elimination (IDDE). Employing GIS-based aerial analysis reduces both cost and time spent in the field. MSD was able to locate, pursue correction, and eliminate failing septic systems and illicit connections. Using these technical approaches, MSD will be able to better prioritize MS4 program activities and do more to improve water quality.