Duke Energy to resubmit plan to close Gallagher coal station basins

May 12—SOUTHERN INDIANA — Shutting down a coal-fired energy-generating facility takes much more than turning off the lights and closing a door.

Duke Energy had been working on plans to close its Gallagher Station years before it officially announced the decision in 2021.

The station was a two-unit, coal-fired generating facility that opened in 1958, according to Duke Energy's website. The station is located in New Albany off Jackson Street.

Submitted in 2016, the plans to close the six coal ash basins at the site were approved by the Indiana Department of Environmental Management in 2019 and 2021.

Concern for the closure of two of those coal ash basins, North Ash Basin and the Primary Pond Ash Fill Area, arose in 2020 by the Hoosier Environmental Council (HEC), and in 2021 by the U.S. Environmental Protection Agency (EPA).

The two groups stated that the two basins in question were subject to federal coal ash rules that the initial plan did not follow.

After Duke Energy received a letter from the EPA in January stating their opinion, the energy company made the decision to withdraw the initial closure plans and resubmit a new plan to the IDEM.

Not all of the basins still hold water, including the North Ash Basin and the Primary Pond Ash Fill. Because they do not impound water and haven't in a long time, Duke Energy spokesperson Angeline Protogere said they did not believe they were subject to the federal coal ash rules.

While Protogere said that they respectfully disagree that the two basins are subject to these rules, they are complying with the EPA in the interest of closing the plant in a timely manner.

In the letter the EPA stated that it has a different interpretation of what is considered to be a Coal Combustion Residuals (CCR) surface impoundment. CCR refers to coal ash.

"The definition of a CCR surface impoundment does not require that the unity prevent groundwater from flowing through the unit, but merely requires that the unit be 'designed to hold an accumulation of CCR and liquid,'" the EPA letter states.

Groundwater simply refers to the water underneath Earth's surface. The U.S. Geological Survey reported that groundwater is the source of about 37% of the water that county and city water departments use to supply households and businesses.

In 2020, the Hoosier Environmental Council (HEC) filed an administrative appeal, saying that IDEM should not have approved the original closure plans.

The Office of Environmental Adjudication rejected HEC's claims and approved the plan, according to Duke Energy's notice of withdrawal sent to IDEM. HEC filed a petition, and the parties are awaiting a hearing.

The EPA's letter stated that Duke Energy will need to implement engineering measures to remove groundwater from the unit before installing the final cover system; Duke Energy will also need to ensure that the basins are closed in a manner that will minimize infiltration of liquids and release of CCR to the maximum extent feasible.

The new plan that Duke Energy is looking to implement is not a foreign concept. In fact, the same plan was already in place for the other four basins at the Gallagher site.

Protogere said that the plan is to de-water the basin, remove hydraulic pressure, grade the area and install an engineered synthetic cap to prevent infiltration of rain after it is closed.

"The engineered solution is designed to ensure the long-term safety of the ash storage and protect groundwater," Protogere said.

With the caps, Duke Energy also plans to install a below-ground slurry wall made of bentonite clay, which has low permeability, Protogere said.

The slurry walls will only be added to the two basins in question and one other basin at the site.

"Slurry walls are a proven technology for controlling the movement of groundwater. We're following Indiana Department of Environmental Management established guidance for constructing the walls," she said.

After a basin is closed in place, Protogere said that in accordance with law Duke Energy will monitor the groundwater for at least 30 years. The results of the monitoring will be reported to state environmental regulators and the public.

Looking at effects of the coal ash basins, Protogere said that they have already been monitoring the groundwater down gradient, and they have reported no impacts from the coal ash reaching the Ohio River.

Down the gradient from the site there is only one drinking well that was used by the plant itself, Protogere said, and it has consistently shown no impacts from the coal ash.

A news release from HEC stated that "Duke Energy's own groundwater sampling, required by the federal coal ash rule, is consistently recording unsafe levels of contaminants such as arsenic, lithium, molybdenum and boron, in the groundwater at the site."

The news release said that the 20 feet or more of buried coal ash at the site is saturated resulting in the continuous leaching of toxic metals into the groundwater.

Protogere said that this statement is misleading.

"The wells that monitor groundwater down gradient between the ash basins and the Ohio River have not shown any impact from coal ash," she said, "There are monitoring wells right next to the ash basin, and not unexpectedly they do show an impact to groundwater."

She noted that Duke Energy is required to address any impact to groundwater, and they are responding to these impacts by capping the basins, adding synthetic liners and adding slurry walls.

Over time, Protogere said that groundwater quality will improve as Duke Energy executes the closure plan.

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