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WINONA LAKE – On Sept. 2, the Lilly Center for Lakes & Streams was alerted to a potential point-source pollution incident on Cherry Creek in Winona Lake.
Testing by the Lilly Center’s research lab confirmed dangerous levels of E. coli present at the source. The Lilly Center conducted additional sampling of Cherry Creek in the following weeks to track E. coli in the water. This report provides on update on the follow-up research.
The town of Winona Lake responded immediately to this incident and has taken steps to identify the source of the pollution and fix the problem, according to a news release from The Lilly Center.
The first set of samples were taken on Sept. 4.
Samples were taken again by the Lilly Center at all five locations the following week on Sept. 10. Results of those tests showed improvement since the town repaired the clogged line and operations returned to normal.
E. coli concentrations at the discharge pipe measured 2,419.6 MPN/100ml, 2,500 MPN/100ml 60 meters downstream, 2,419.6 MPN/100 ml at the Lilly Center site and 1,553.1 MPN/100ml at the mouth of Cherry Creek. The location upstream of the discharge was 686.7 MPN/100 ml. The values at the discharge and downstream are all substantially lower than recorded the previous week, according to the release.
On Sept. 15, the Lilly Center collected another set of samples upstream of the discharge, downstream of the discharge and at the mouth of Cherry Creek where it enters Winona Lake. A sample was not collected at the discharge because no effluent was exiting the pipe.
E. coli levels continue to decrease at the sample sites but are still above the IDEM standard of 235 MPN/100ml. At the site approximately 60 meters downstream of the discharge, the E. coli concentration was 2,419.6 MPN/100ml. This is slightly lower than levels recorded five days prior. Similarly, E. coli levels at the mouth were roughly 500 MPN/100ml lower on Sept. 15 compared to the previous sample on Sept. 10. The site upstream of the discharge was also lower compared to the previous sample.
A fourth round of sampling was conducted by the Lilly Center on Sept. 22. Samples were collected at all five of the locations sampled on the Sept. 4 and 10.
Results from Sept. 10 showed that E. coli concentrations were still near the maximum values the test could provide without diluting the samples. Consequently, samples collected on Sept. 22 were diluted by a factor of 10 to ensure that precise values could be recorded.
E. coli concentrations at all sites were still well above the EPA safety threshold of 235 CFU/100 ml. The most upstream site increased substantially from the previous week and may have been influenced by the rain event that occurred Sept. 20, the release states. No water was flowing out of the discharge pipe and the sample was collected in the stream immediately beneath the pipe. At this location, the E. coli concentration was 2,380.0 MPN/100ml and concentrations were similar at the next two downstream sampling locations. At the confluence of Cherry Creek and Winona Lake, E. coli measured 780.0 MPN/100 ml. While this is substantially lower than the upstream locations, this level is still over three times the acceptable concentration.
The Lilly Center will continue to investigate this situation and provide relevant updates.
For more information on The Lilly Center, visit lakes.grace.edu.
