Kansas City, Missouri Overflow Control Plan Summary

Kansas City began building the basic sewer infrastructure that would allow the City to grow and prosper over 150 years ago. Amazingly, some of that infrastructure is still in use today. While focused on controlling overflows, a significant portion of the Overflow Control Plan addresses repairing, improving, and maintaining the City's basic sanitary sewer system so that it can be used by Kansas Citians for years to come. Kansas City's overall sanitary sewer system is comprised of both combined and separate sewer systems. A combined sewer system is simply a single sewer system that carries both sewage and stormwater. Kansas City has 58 square miles of combined sewers. Typically these systems are in the oldest areas of the City and are not capable of carrying the large amounts of stormwater that now run off of our urban landscape. During moderate to heavy rainfall events, the system will reach capacity, overflow, and discharge a mixture of sewage and stormwater directly to our streams and rivers. Although there is a desire to minimize these overflows, the discharge of combined sewer overflows is not uncommon from combined sewer systems and is allowed under a National Pollutant Discharge Elimination System (NPDES) permit issued to Kansas City's Water Services Department by the Missouri Department of Natural Resources.