Three environmental groups intend to sue Alliant Energy subsidiary Interstate Power and Light, alleging that groundwater discharges from the Ottumwa coal plant's coal ash impoundment in Iowa violate the Clean Water Act.
The groups — the Iowa Environmental Council, Sierra Club, and Environmental Law & Policy Center — filed a formal notice to sue the utility on 12 March, initiating a 60-day period for the company to respond and comply with the Clean Water Act.
The environmental groups claim Ottumwa has continued to release groundwater with arsenic and other toxic pollutants into the Des Moines River through a drain under the plant's lined coal ash pond despite being told by Iowa regulators in 2023 that such releases were not allowed under the plant's stormwater permit. The utility also has not applied for a new permit since the Iowa Department of Natural Resources mentioned the issue, the groups claim.
"We want the unpermitted pollution to stop," said Environmental Law & Policy Center senior attorney Josh Mandelbaum. "We will evaluate any response by the utility, but if there continues to be unpermitted pollution, we intend to act."
Alliant said that it is abiding by all regulated and required groundwater monitoring processes. The company "proactively" reached out to the Iowa Department of Natural Resources about the permit and has been "actively communicating" with the department while "systematically working" toward a solution for the groundwater discharge. "The system under the landfill is engineered so the groundwater does not come into contact with the contents of the landfill," the coal plant operator said in its statement.
Still, environmental groups insist that "a solution has not been implemented and Alliant continues its unpermitted discharge".
The Ottumwa coal plant received 1.27mn short tons (1.15mn metric tonnes) of coal from four Wyoming mines in 2024, according to the most recent US Energy Information Administration data.
