Iowa’s largest utility is doing away with its coal ash ponds. Instead of putting the toxic dust in wet pits, the MidAmerican Energy Company will put it in sealed landfills, or recycle it.
The changes come after the rollout of an Obama-era rule that set new requirements for how power plants should get rid of the ash, which contains lead and arsenic and has been linked to cancer, kidney disease and other conditions.
Jerry Schnoor is an environmental engineer at the University of Iowa. He says the industry is phasing out the ponds because they’re more likely to allow the dust to leak into the groundwater.
“There won’t be any new ponds of these disposals. And the existing ones, the trend is to take care of the existing ones, likely for the same reasons MidAmerican is doing it: to take care of future liability and problems,” Schnoor said.
The change comes after two costly coal ash spills in recent years. The Tennessee Valley Authority Kingston spill in 2008 sent approximately 4.1 million cubic meters of ash sludge into the Emory and Clinch River System. In 2014, coal ash from a Duke Energy plant leaked into North Carolina's Dan River, which is a source of drinking water for residents in North Carolina and Virginia.
But the potential impacts of coal ash aren't always that obvious. Schnoor says over time the toxins can seep into the environment. But he says properly-lined dry landfills can contain the material better than the wet slurries can.
“If they’re not lined, it’s easier for the leachate, these metals that we talked about and metalloids, to impact to the groundwater, to leach into the groundwater,” Schnoor said.
He says the changes are a step towards preserving Iowa's water quality.
MidAmerican Energy has begun phasing out ash pond deposits at its plants and says it will continue to recycle as much of the material as it can, using it for concrete. The company will put the rest of the ash in lined landfills by this August.
According to the Iowa Department of Natural Resources, the state has 27 coal ash ponds.