CINCINNATI — Research released Wednesday by University of Cincinnati students found "alarming levels" of human E. coli in Burnet Woods Park likely tied to combined sewer overflow events, according to a release from UC professor Bob Hyland.
The research was conducted by an interdisciplinary team of undergraduates at UC.
The students investigated E. coli levels in the soil at Burnet Woods Park after "a combined sewer overflow event" late Wednesday, April 2 and into early Thursday, April 3. During that time frame, many communities in the Tri-State were dealing with heavy rains that caused widespread flooding in the days that followed.
According the the U.S. Environmental Protection Agency, a combined sewer system collects everything, including rainwater runoff, domestic sewage and wastewater into one pipe; when the amount of runoff exceeds the capacity of the system, untreated storm and waste water can flow into nearby bodies of water.
The Ohio EPA no longer allows the installation of combined sewers, because of their pollution concerns, according to the agency's website.
At Burnet Woods, the UC students found that samples taken at 8 hours, 24 hours and 72 hours after the overflow event contained high levels of E. coli colony-forming units (CFUs).
A sample taken at the 8-hour interval found there was 130,400 CFUs per 100 mL of water — or 600 times the amount of E. coli permitted for recreational waters, according to the release.
The samples were taken at three different locations in the lower valley of the park, each at an increasing distance from the source of the overflow. The samples showed the E. coli levels spiked at 8 hours following the overflow, with "expected but incomplete declines" in the level of CFUs after 24 and 72 hours.
"More research should be conducted in Burnet Woods, as well as other Cincinnati parks with non-enumerated CSOs, to better understand the scope and severity of the risk, as well as the rate of CFU decline under different conditions," reads a preliminary report on the data found.
