Just 10 years ago, a heavy rain in Atlanta could turn Tanyard Creek into a river of raw sewage. “You would sometimes see toilet paper hanging from low branches along its banks,” recalls Gonzalo Vazquez-Prokopec, a disease ecologist in Emory’s Department of Environmental Sciences.
Few fish or turtles were evident in the stream, which flows alongside expensive Buckhead real estate. But larvae from the Culex quinquefasciatus mosquito, the main vector of West Nile virus in Atlanta, thrived in the polluted waters.
Today, that scene is largely reversed, following the remediation by the city of Atlanta of a combined sewage overflow (CSO) facility connected to Tanyard Creek. A five-year study led by Emory researchers gathered the before-and-after data to prove it.
“This is the first study that shows how the construction of a deep storage tunnel for a CSO system not only improves stream health and water quality but reduces the mosquitoes that spread West Nile virus,” Vazquez-Prokopec says.