Around the Water Cooler: Soaking up Rainfall and Reducing Sewage Overflows

By Katie Lubinsky

Did you know that 14 billion gallons of untreated sewage overflows each year into Mill Creek from Cincinnati’s combined sewer system? Such overflows can harm environmental and public health and put cities, including Cincinnati, in violation of the Clean Water Act, resulting in costly fines.

In an attempt to mitigate this issue, EPA hydrologist Dr. Bill Shuster is leading a team of scientists to explore how cities can tap rain gardens and other types of “green infrastructure” in Cincinnati and other cities with combined sewer systems.

Combined sewer systems involve a network of grates and pipes that combine storm water runoff and wastewater—from streets, homes and businesses—into one major underground pipe where it flows towards a treatment plant. When heavy rains lead to too much water for the system to handle, the excess overflows directly into a nearby water body, untreated.

I met and filmed Dr. Shuster to explore how cities like Cincinnati can reduce the amount of water flowing into sewer systems. While traveling to a rain garden with Dr. Shuster, I noticed row-after-row of vacant lots. Where buildings had once stood, the lots are now filled with hard soil that acts like impermeable cement, shedding rainfall into the combined sewer system. Dr. Shuster’s research shows how green infrastructure could replace these vacant lots and reduce runoff.

While filming, I learned about Dr. Shuster’s research: green infrastructure soaks up stormwater and reduces the amount and rate of water going into the combined sewer system. Rain gardens are Dr. Shuster’s specialty. He helps install and measure their effectiveness in reducing runoff. Green Infrastructure combines good soils with plants that are tolerant of both drought and heavy rains. The rainfall is stored and infiltrated into the gardens, where it can provide water to other plants near by keeping excess water out of the sewer system!

His research is gaining momentum in other areas with combined sewer systems, most recently in Omaha, Nebraska. It not only helps the systems work well, but these rain gardens and green spaces aesthetically enhance communities and provide other important ecosystem services such as habitat and food for pollinators.

Instead of row-after-row of vacant lots or abandoned houses in our neighborhoods, green infrastructure can replace them and have positive effects for all.

About the author: Katie Lubinsky is a student contractor working with EPA’s Office of Research and Development.

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