A new Environmental Protection Agency rule will require a westside power plant that used coal for decades to clean up coal ash storage ponds if they’re found to be contaminated.
The change would affect at least four coal ash ponds at the AES Indiana Harding Street Station, which have, for nearly a decade, gone without inspections and groundwater monitors.
When the plant burned coal for electricity, it left behind a residue called coal ash that contains toxic heavy metals, some of which have been known to cause cancer. That residue was stored in deposits, called impoundments, or ponds, just south of the plant and just a few hundred feet from the White River, threatening the water source for thousands of Hoosiers.
But we only know how much coal ash exists in half the ponds in Indianapolis and whether they’re safe. That’s because of a rule implemented in 2015. According to groundwater monitors, the ponds are leaking heavy metals into groundwater.
The 2015 rule, though, came with a loophole that exempted ponds that closed before the rule took effect.
Now the new EPA rule, which is expected to be implemented in six months, will close that loophole — and we’ll find out how much coal ash exists in the other half of the ponds, and potentially begin the process of cleaning them up.
“The Harding Street coal ash has been documented to have contaminated the groundwater significantly, including arsenic at levels that are more than tenfold above the drinking water standard for arsenic,” said Indra Frank, director of water policy for the nonprofit Hoosier Environmental Council. “Unfortunately, the groundwater doesn’t hold still, so the contaminated groundwater from the Harding Street plant flows toward the White River and gets into the White River that way.”
AES Indiana said it was too soon to know how the new rule would affect how the company would address the coal ash ponds at the Harding Street Station.
“We are currently reviewing the rule and supporting materials to determine potential impacts to AES Indiana. AES Indiana is committed to complying with environmental regulations and ensuring the safety of our work, people and communities,” said Kelly Young, public relations director of AES Indiana.
The rule change was spurred by a 2022 lawsuit filed by Earthjustice on behalf of the Hoosier Environmental Council, the Indiana State Conference and LaPorte County Branch of the NAACP, other environmental groups in Tennessee and Illinois, Sierra Club and the Environmental Integrity Project.
“We’ve definitely seen problems with enforcement here in Indiana, and my hope is that, with this revised rule, we will also see an uptick in enforcement from EPA and from IDEM (Indiana Department of Environmental Management),” Frank said.
The problem isn’t just in Indiana. According to Earthjustice, 91% of all coal-fired power plant sites nationwide are polluting groundwater at levels above the federal standards.
Coal ash in Indianapolis
In Indiana, there are 100 coal ash ponds spread over 16 power plants. According to nonprofit Earthjustice, the ponds have contaminated groundwater at all plants.
That includes the AES Indiana Harding Street Station at 3700 S. Harding St., which has eight total coal ash ponds that have operated since 1958.
Four ponds hold about 6.5 million cubic feet of coal ash. It’s unclear how much more coal ash is in four other ponds.
Groundwater monitors at the regulated coal ash ponds at the Harding Street Station have detected arsenic, lithium and molybdenum at levels above federal safety standards. The metals also have migrated offsite, into a neighboring quarry.
Arsenic has been linked to skin, lung, bladder, kidney and liver cancers, diabetes and preterm births; lithium is linked to kidney and neurological damage; and molybdenum exposure has been linked to high levels of uric acid in blood, which causes gout and achy joints.
At least two of the ponds there have been classified by independent contractors as posing “significant hazard potential” due to the environmental damage coal ash from the ponds could cause to downstream areas as a result of a failure or misoperation at the ponds.
“Those coal ash impoundments are all in the floodplain of the White River,” Frank said. “Technically, the berms around those impoundments are high enough to be above the 100-year flood level, but those berms themselves are made out of coal ash.”
It’s unclear how much coal ash is in the four unregulated ponds or how likely it is to fail. AES Indiana is not required to keep those records. More coal ash could also lie on plant property outside the pond.
“There’s a lot of coal ash that was used as fill on the Harding street site, so it was basically disposed of on the ground just to fill in low-lying areas,” Frank said.
Coal ash threats all over the state
Coal ash pond failures have occurred throughout the state.
In Martinsville, the AES Indiana Eagle Valley Generating Station sent 30 million gallons of coal ash mixed with water, called ash sluice, into the White River on two different occasions: once on Valentine’s Day 2007 and again a little less than a year later in January 2008.
The Indiana Department of Environmental Management found that both the internal and external levees at the impoundments failed, allowing the ash sluice to enter the White River via a water discharge canal.
AES Indiana, at the time Indianapolis Power & Light, had to pay a $23,800 civil penalty and perform a study of its ash pond levees. The company later petitioned the EPA to lower the classification risk for the coal ash ponds that failed from “high” to “significant.” All of the regulated ponds at the date are currently classified as posing “significant” hazard potential.
In northern Indiana, a landfill by the retired NIPSCO Bailly Generating Station that was used to store coal ash decades ago was found to leak many chemicals, mainly boron, into the Indiana Dunes National Park. High levels of boron can affect the stomach, liver, kidneys and brain in humans and can inhibit plant growth in the environment.
Mirror Indy reporter Enrique Saenz covers west Indianapolis. Contact him at 317-983-4203 or enrique.saenz@mirrorindy.org. Follow him on X @heyEnriqueSaenz
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