An environmental study by the Iowa Department of Natural Resources in spring 2017 reported the main body of Cedar Lake was safe for human recreation, but sought additional study in the west cell where elevated levels of contaminants were found.
Fully vetting the lake was deemed necessary before ownership transferred from Alliant Energy, which for decades used the 100-plus acre lake as a cooling pond for the now-decommissioned Sixth Street SE power plant, to the city of Cedar Rapids.
City officials have been working with an advocacy group, Friends of Cedar Lake, for several years on a restoration plan. A master plan calls for fishing and kayaking and enhanced aesthetics.
What’s happened since
Additional studies have been completed and more investigations are being sought.
Alliant hired Burns & McDonnell Engineering Company of Madison, Wis., to conduct a sediment investigation in August 2017 to help determine the source of contaminants, such as banned pesticides, chlordane, polychlorinated biphenyl or PCBs, cadmium, arsenic, chromium, lead and mercury. After revisions and additional sampling, that was completed in July.
Dan Cook, senior environmental specialist with the Iowa DNR, said sampling showed elevated concentrations of metals and polycyclic aromatic hydrocarbons, or PAHs, in the west lake, which received the outflow of the power plant, and lower concentrations in other parts. Toxins such as chlordane, banned pesticides and PCBs — which are consistent with stormwater runoff — showed up in higher concentrations near the Kenwood ditch and McLoud Run and lower concentrations in the west portion, he said.
“Contaminants in the rest of the lake don’t look like they came from the power plant,” Cook said. “It looks like it came from the Kenwood ditch or the creek on the north side. Chemicals in the rest of the lake are runoff from streets: pesticides, small spills, things put on the yard.”
While the west section poses the greatest threat, the Iowa DNR remains concerned about ecological risks to fish and microorganisms throughout the lake, he said. He reiterated the lake remains safe for human use.
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Iowa DNR recommended a screening-level ecological risk assessment of the west lake. Alliant plans to have a workplan for that ready in October, and when approved, begin the work, Cook said. Alliant ultimately will be responsible for a remediation plan once investigation is completed, he said.
Because no party could be identified as responsible for contaminants in other parts of the lake, some organization, possibly the city, should step up to address it, Cook said.
“If they want full and unrestricted use of the lake, it should be done,” he said of additional ecological studies.
Cook said additional studies in the overall lake could be avoided by simply dredging, which would remove the PAHs.
Bill Micheel, assistant director community development for the city of Cedar Rapids, said the latest study is consistent with previous findings. He acknowledged the timetable for transfer has been pushed back, but said the city still is looking forward to a transfer of property. The city has committed $5 million — pending Friends of Cedar Lake can come up with the rest of the money — to a $20 million project to restore Cedar Lake and construct a Smokestack Bridge using old Rock Island Railroad bridge piers south of downtown over the Cedar River between New Bohemia District and Czech Village.
Mike Wagner, a spokesman for Alliant, said once additional sampling is complete, “we can begin conversations with the city on the next steps for property ownership.”
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