State EPA officials blame Lake Iroquois fish kill on 'lake turnover'

State EPA officials blame Lake Iroquois fish kill on 'lake turnover'

LAKE IROQUOIS — Illinois Environmental Protection Agency field staff believe naturally occurring "lake turnover" was to blame for thousands of fish dying at Lake Iroquois on a recent weekend, an agency spokesman said.

Testing of water samples from the lake near Loda detected "very low" levels of the herbicide atrazine, but otherwise came up clean, said IEPA spokeswoman Kim Biggs.

"The samples were tested for pesticides and showed 'No Detect' for all parameters with the exception of Atrazine," Biggs said Wednesday. "The atrazine detected was at very low levels, and well below both the maximum concentration level for drinking water and the aquatic-life-use attainment levels that have been established.

"Given the results, it is the opinion of our field staff that the fish kill likely resulted of lake turnover, which is naturally occurring."

Jim Shearl, chairman of the Lake Iroquois Association board's recreation committee, had said previously that he believed the July 8 fish kill was caused by the fish not getting enough oxygen due to lake turnover. Shearl noted that the lake's water appeared "very muddy," which lines up with the theory.

Shearl said routine testing of the water by the Illinois Department of Public Health showed there are no E.coli bacteria issues in the lake. Still, no swimming is allowed yet.

"The (swimming) beach will not be open for swimming even though we got one good test" from the IEPA after the fish kill, Shearl said. "We want at least one more, maybe two" before reopening it for swimming.

Will Brumleve is editor of the Ford County Record, a News-Gazette Media community newspaper. For more, visit