Environmentalists plan to raise concerns at a public hearing tonight about water-quality issues caused by Ameren Missouri's Rush Island Energy Center in Festus.
The Missouri Department of Natural Resources is in the process of renewing a water discharge permit for the Rush Island plant. But for the first time, the plant will be required to conduct groundwater monitoring as part of the state's efforts to increase oversight of contamination caused by ponds that coal-fired power plants use to dispose waste. Coal ash waste contains arsenic, mercury and other heavy metals that can harm human health. Rush Island has one pond, which the company plans to close by 2020.
The Sierra Club Missouri Chapter and Washington University lawyers want state environmental regulators to take stronger action to address contamination from Rush Island's coal ash pond.
"Our main concern is that we feel like this permit is legalizing groundwater contamination because we know there is existing contamination that has been found at that site," Edgar said, "and we want to make sure that is dealt with sooner rather than later."
Ameren Missouri recently released groundwater monitoring reports that describe the risks that its 15 coal ash ponds pose to the environment.
"The underlying conclusion is that there's no harm to human health or the environment as a result of the activities at Rush Island," said Craig Giesmann, manager of water quality at Ameren Missouri.
Edgar also expressed concerns about the plant's thermal pollution, the heated water that the plant discharges into the nearby waterways, and the risks that could pose to aquatic wildlife. Ameren officials pointed to data collected in 2016 that indicated that the water temperature only rises by 0.3 degrees Fahrenheit.
The hearing will take place at 6 p.m. at the Quality Inn in Festus.
Follow Eli on Twitter: @StoriesByEli