Two types of sewer systems support Kansas City: combined and separate.

In the combined sewer system, stormwater and wastewater are collected in the same pipe, and routed to a wastewater treatment plant for treatment. These are the oldest pipes in our system and are located in the older parts of our city.

As technology advanced, it became best practice to use more than one pipe. In the separate sewer system, stormwater and wastewater are collected in two different pipes. Wastewater is collected and conveyed to a wastewater treatment plant for treatment, and stormwater flows directly to nearby creeks, streams, and rivers without treatment.

When it rains, the combined sewer system that uses one pipe to convey both wastewater and rainfall can quickly fill up and reach its capacity — and even overflow at established outfall locations, discharging a mix of wastewater and stormwater directly into our local streams and rivers.

KC Water’s Smart Sewer program — the City’s largest infrastructure investment — is committed to constructing nearly 100 wet weather overflow control projects to reduce the volume of overflows and protect our natural environment.