Representatives from the Iowa Department of Natural Resources will hold a meeting to discuss water quality improvement plans for Hickory Grove Lake, the body of water located approximately 2.5 miles southwest of the city of Colo that was placed on the impaired waters list in 2018.
Hickory Grove Lake is on the list of impaired waters after a report found high levels of E.coli bacteria in more than 30 samples taken from the lake — with as many as 24,000 E.coli cells per 100 mL of water at one point in August 2018.
The DNR announced on Friday meetings would be held this month to address water quality issues in Hickory Grove Lake, as well as Nine Eagles Lake in Davis City, and Clear Lake in Cerro Gordo County.
On March 24, representatives from the DNR will be in the Nevada Senior Community Center to discuss plans for the Hickory Grove Lake.
The meetings are designed to identify the amounts and contributing sources of bacteria entering the lake and offer potential solutions to reduce those levels and work toward fixing the problems that lead to contamination, according to officials with the DNR.
Since 2018, the interior of Hickory Grove Park has been under construction — including closures to the entire lake,beach, concessions, open shelter houses on the north side of the lake — as a part of a $3.4 million lake restoration project. The project includes draining and restoring the lake.
In 2015, the Iowa DNR started a two-year water quality study to assess the relationships between the nearshore beach environment and open lake conditions.
E. coli and other harmful pathogens can be found in a lake or stream, and can originate from point or nonpoint sources of pollution, or a combination of both.
A point source of pollution can be traced to sources that enter a stream or lake at a distinct location, such as a wastewater treatment plant discharge.
Nonpoint sources are often more difficult to locate and quantify.
According to the report, Hickory Grove Park’s open park environment could be a contributing factor to the prevalence of E. coli in its water.
“The alternate transect on this lake was established along a shoreline, which was routinely mowed and sloped steeply to the water,” said an excerpt from report. “This open park-like area was frequently observed being used as a grazing/loafing area for 30 to 60 geese.”
DNR staff told the Tribune the number of E. coli cells should not exceed 200 per 100 mL of water on average over a 30-day period.
According to the report, the mean average of E.coli cells in the Hickory Grove Lake is 704 cells per 100 mL.