The company’s Gallagher Station, along the Ohio River in west New Albany, is one of 15 or 20 coal-burning facilities that are shutting down across the state. Plans associated with the closing of Duke Energy’s Gallagher Station and others are under review by the Indiana Department of Environmental Management.

The utility company has proposed a variety of methods to deal with its five New Albany coal ash basins, or ponds that act as disposal sites for the byproducts of burning coal. Some coal ash will be excavated and stored in lined landfills, while other basins will be closed and sealed in place.

The close-in-place method involves dehydrating the ponds and containing its contents with a cap, both methods Duke Energy says reduces the potential for contamination.

But environmentalists claim leaving millions of tons of ash in a basin without a liner may cause it to soak below the water table, especially because of its proximity to the Ohio River. They say the safest method to close basins is to excavate coal ash and move it to dry, lined landfills away from waterways.

“The utility’s plan clearly fails to protect the environment and people’s health from dangerous contaminants leaking off the sites,” Indra Frank, environmental health and water policy director for the Hoosier Environmental Council, said in a news release. “The waste contains lead, arsenic and chromium, among other toxics, and it should be prevented from continuing to leak into Indiana waters.”

The public interest groups are also calling on Duke to prepare a “comprehensive cost-benefit analysis” that explores alternatives to its proposed close-in-place method.

“At every site Duke chose the cheapest option in the short-term, but failed to consider the high cost of cleaning up the pollution that is sure to result from simply covering the ash dumps in place,” said Sierra Club Hoosier Chapter Director Bowden Quinn. “Keeping the toxic ash away from water is the only proven way to prevent contamination.”

Duke Energy spokeswoman Angeline Protogere disputed that claim, saying the utility company’s closure plans are “based on extensive engineering and scientific studies by independent experts for each basin.”

“We have evaluated different closure options and developed customized solutions for each basin, guided by comprehensive study and engineering to meet strict state and federal requirements,” Protogere wrote in an email. “We did all this with consideration of the impacts on the surrounding community and broader environments.”

Removing water from the ponds “dramatically slows the process of transferring trace elements in the ash to the groundwater and begins improving groundwater quality,” she said. Installing a synthetic cap, versus a soil cap, is a step above EPA’s minimum requirements, she said.

Basins that are closed in place will be subject to 30 years of groundwater monitoring. Protogere said there’s only one drinking well near Gallagher Station, and it services the plant. Water from that well has been tested and meets health-based drinking standards, she said.

IDEM hosted a public meeting in May over Duke Energy’s closure plans for Gallagher Station. Its comment period has closed, though environmentalists are encouraging people to still contact IDEM with their thoughts.

IDEM spokesman Barry Sneed said the agency is currently reviewing the plans.

“Our staff of professional engineers and geologists evaluate these plans to ensure they meet state and federal rules and regulations and are protective of human health and the environment,” Sneed said in an email.

He added that Duke Energy’s coal ash landfills in Indiana have “in general” complied with requirements.

Duke Energy gained notoriety in 2014 when coal ash dumps in North Carolina spilled up to 39,000 tons of ash through a leaking stormwater pipe in a 70-mile stretch of the Dan River. The nation’s largest utility company pleaded guilty a year later to nine misdemeanor counts after ignoring repeated warnings about pollution issues at its facilities, according to a report published by the Chicago Tribune.

“Duke Energy should learn from its mistakes,” Pete Harrison, Waterkeeper Alliance attorney, stated. “Instead, the company is trying to abandon its coal ash in leaky pits next to Indiana’s biggest rivers, where it will endanger people, fish and the rivers for decades to come.”

The coal ash pits that spilled into the river were inactive but not yet drained and closed, Protogere said. Duke Energy has confirmed that there are no stormwater pipes under the Gallagher Station basins.

“Third-party engineering inspections and studies following the accident produced a list of projects we initiated fleet-wide to ensure ash basins continue functioning safely through closure,” she said.

Coal ash basins are inspected weekly by Duke Energy engineers and more thoroughly during annual inspections, Protogere said. Significant rainfall also requires special inspections.

Elevated levels of boron were found in residential drinking wells at Duke Energy’s Gibson station in Owensville. The federal EPA only sets guidelines, not requirements, for allowable levels of boron in drinking water. Protogere said Duke Energy “voluntarily” piped in municipal drinking water to all residents who drew water from the contaminated wells.