September 2, 2025
Toxic Coal Ash in Indiana: Addressing Coal Plants’ Hazardous Legacy
For many decades, utilities dumped billions of tons of coal ash — the toxic substance left after burning coal — in unlined ponds, landfills, and mines where the toxic pollution leaks into water and soil.
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Across the U.S., immense coal ash dumps are leaking hazardous chemicals including arsenic, chromium, lead, lithium, radium, and other heavy metals, which have been linked to numerous types of cancer, heart and thyroid disease, respiratory illness, reproductive failure, and neurological harm. In addition to those well-known health threats, in 2023, the Environmental Protection Agency acknowledged that coal ash contains levels of arsenic and radiation that pose cancer risks.
Coal ash remains one of our nation’s largest toxic industrial waste streams. U.S. coal plants continue to produce approximately 70 million tons every year. Coal ash is disproportionately located in low-income communities and communities of color.
Industry’s own data indicate that across the country almost all coal plants are polluting water above federal safe drinking water standards.
Despite regulations established a decade ago, the coal industry has failed to comply with federal safeguards and uses deceptive tactics to avoid cleaning up its coal ash.
Because of industry’s widespread violations of coal ash regulations, in 2023, the EPA ramped up enforcement after designating coal ash a national enforcement priority. The EPA reports that many plants are illegally closing coal ash ponds with toxic ash sitting in groundwater, threatening drinking water and the health of nearby residents.
The longer industry delays, the more toxic waste enters our water, and the more difficult cleanup becomes. But the coal industry is asking Trump’s EPA to let them off the hook.
Action Needed
Federal coal ash protections established in 2015 and 2024 require monitoring, closure, and cleanup of the more than 1,000 coal ash dumps across the country. Cleaning up coal ash now will not only prevent another billion-dollar catastrophic failure, it will preserve drinking water; protect rivers, streams, and lakes; and allow safe redevelopment of power plant sites.
The magnitude of harm from recklessly dumped toxic coal ash requires decisive action from federal and state regulators:
- Power companies must be required to comply with the law and immediately clean up their pollution, including removing any coal ash in contact with groundwater.
- When power companies retire coal plants, they must clean up their toxic mess and leave communities with sites that benefit rather than harm their health, environment, and economy.
- EPA and states must prohibit the use of coal ash as a substitute for clean soil in construction (known as structural fill), especially in residential areas, and ensure cleanup of areas where ash was used as fill.
Click on plant locations on the map to see industry reports
Coal Ash in Indiana
| A.B. Brown | SIGECO | 2 pond(s), 1 landfill(s), and 2 potential ash dump(s) | 2 potential ash dump(s) | 11,532,600 | Arsenic (x2), Boron (x7), Cobalt (x1), Lithium (x2), Molybdenum (x38), Sulfate (x28), Thallium (x1) | IN-08 (Mark Messmer) |
| AES Petersburg | AES Indiana | 3 pond(s), 1 landfill(s), and 1 potential ash dump(s) | 1 potential ash dump(s) | 9,883,216 | Arsenic (x6), Beryllium (x1), Boron (x18), Cadmium (x2), Cobalt (x65), Lithium (x51), Molybdenum (x64), Sulfate (x2), Thallium (x13) | IN-08 (Mark Messmer) |
| Bailly | Northern Indiana Public Service Co. | 4 pond(s), and 4 potential ash dump(s) | 4 potential ash dump(s) | 65,000 | Arsenic (x8), Cadmium (x2), Lithium (x2), Molybdenum (x16), Thallium (x5) | IN-01 (Frank Mrvan) |
| Breed | American Electric Power | 1 legacy pond(s), and 1 potential ash dump(s) | 1 legacy pond(s), and 1 potential ash dump(s) | Failed to report volume | No groundwater data reported | IN-08 (Mark Messmer) |
| Cayuga | Duke Energy Indiana, Inc. | 3 pond(s), 1 landfill(s), and 2 potential ash dump(s) | 2 potential ash dump(s) | 15,096,278 | Arsenic (x5), Boron (x5), Cobalt (x4), Lead (x4), Lithium (x11), Molybdenum (x45), Sulfate (x2) | IN-08 (Mark Messmer) |
| Clifty Creek | Indiana-Kentucky Electric Corp. | 2 pond(s), 1 landfill(s), and 1 potential ash dump(s) | 1 potential ash dump(s) | 8,184,566 | Arsenic (x7), Boron (x5), Lithium (x14), Molybdenum (x64), Sulfate (x2) | IN-09 (Erin Houchin) |
| Dean H. Mitchell | Northern Indiana Public Service Co. | 6 legacy pond(s) | 6 legacy pond(s) | 49,700 | No groundwater data reported | IN-01 (Frank Mrvan) |
| Dresser Station | Duke Energy Indiana, Inc. | 1 potential ash dump(s) | 1 potential ash dump(s) | 402,305 | No groundwater data reported | IN-08 (Mark Messmer) |
| Eagle Valley | AES Indiana | 3 pond(s), and 2 potential ash dump(s) | 2 potential ash dump(s) | 2,855,595 | Arsenic (x9), Boron (x4), Lithium (x3), Molybdenum (x6) | IN-04 (Jim Baird) |
| Edwardsport | Duke Energy Indiana, Inc. | 2 likely inactive pond(s), and 1 potential ash dump(s) | 1 potential ash dump(s) | 935,400 | No groundwater data reported | IN-08 (Mark Messmer) |
| F.B. Culley | SIGECO | 2 pond(s) | None estimated | 1,486,300 | Arsenic (x9), Boron (x27), Cobalt (x1), Lithium (x6), Molybdenum (x24), Sulfate (x3) | IN-08 (Mark Messmer) |
| Frank E. Ratts | Hoosier Energy REC, Inc | 3 legacy pond(s), and 2 potential ash dump(s) | 3 legacy pond(s), and 2 potential ash dump(s) | 5,700,000 | No groundwater data reported | IN-08 (Mark Messmer) |
| Gibson | Duke Energy Indiana, Inc. | 4 pond(s), 1 landfill(s), and 3 potential ash dump(s) | 3 potential ash dump(s) | 40,226,301 | Arsenic (x10), Boron (x22), Cobalt (x3), Lithium (x24), Molybdenum (x35), Selenium (x2), Sulfate (x3) | IN-08 (Mark Messmer) |
| Harding Street | AES Indiana | 4 pond(s), and 4 potential ash dump(s) | 4 potential ash dump(s) | 3,484,794 | Antimony (x2), Arsenic (x45), Boron (x21), Lithium (x13), Molybdenum (x18), Sulfate (x3) | IN-06 (Jefferson Shreve) |
| Merom | Hoosier Energy | 1 landfill(s), and 2 potential ash dump(s) | 2 potential ash dump(s) | 3,791,504 | Fluoride (x1) | IN-08 (Mark Messmer) |
| Michigan City | Northern Indiana Public Service Co. | 2 pond(s), and 5 potential ash dump(s) | 5 potential ash dump(s) | 1,670,000 | Arsenic (x4), Boron (x2), Selenium (x1), Thallium (x2) | IN-01 (Frank Mrvan) |
| Noblesville | Duke Energy Indiana. Inc. | 1 potential ash dump(s) | 1 potential ash dump(s) | 599,000 | No groundwater data reported | IN-05 (Victoria Spartz) |
| R. Gallagher | Duke Energy Indiana, Inc. | 3 pond(s), 1 landfill(s), and 12 potential ash dump(s) | 12 potential ash dump(s) | 6,351,000 | Arsenic (x6), Boron (x11), Cobalt (x2), Lithium (x1), Molybdenum (x31), Sulfate (x1) | IN-09 (Erin Houchin) |
| R.M. Schahfer | Northern Indiana Public Service Co. | 4 pond(s), 1 landfill(s), and 3 potential ash dump(s) | 3 potential ash dump(s) | 3,016,996 | Arsenic (x6), Boron (x17), Cobalt (x6), Fluoride (x10), Lithium (x7), Molybdenum (x76), Radium 226+228 (x2), Sulfate (x15) | IN-04 (Jim Baird) |
| Rockport | American Electric Power | 1 pond(s), 1 landfill(s), and 4 potential ash dump(s) | 4 potential ash dump(s) | 8,281,788 | Arsenic (x2), Boron (x13) | IN-08 (Mark Messmer) |
| State Line Energy | Sam Townline Development, Inc. | 1 legacy pond(s) | 1 legacy pond(s) | No data yet | No groundwater data reported | IN-01 (Frank Mrvan) |
| Tanners Creek | Tanners Creek Development, LLC | 5 legacy pond(s), and 1 potential ash dump(s) | 5 legacy pond(s), and 1 potential ash dump(s) | 3,257,000 | No groundwater data reported | IN-09 (Erin Houchin) |
| Wabash River | Duke Energy Indiana, Inc. | 4 pond(s) | None estimated | 7,375,000 | Arsenic (x2), Boron (x25), Cobalt (x3), Lead (x1), Lithium (x5), Molybdenum (x39), Sulfate (x3) | IN-08 (Mark Messmer) |
| Warrick | AGC Division of APG, Inc. | 1 likely inactive pond(s) | None estimated | No data yet | No groundwater data reported | IN-08 (Mark Messmer) |
| Whitewater Valley | Richmond Power & Light | 1 pond(s), and 4 potential ash dump(s) | 4 potential ash dump(s) | 395,700 | Mercury (x6), Molybdenum (x3) | IN-06 (Jefferson Shreve) |
* Total volume of coal ash at the site has been compiled from reports filed with the Indiana Department of Environmental Management as well as from reports posted by owners and operators, as required by federal coal ash rules.
** Parentheticals indicate magnitude of exceedance above federal health-based guidelines for drinking water based on industry data and analysis described in the report, Poisonous Coverup. See summaries of EPA reports.
Massive quantities of coal ash are stored at 24 current and former power plants sites in Indiana.
Most sites include older coal ash dumps that industry is only now beginning to quantify and monitor.
Power plant owners must report on an estimated 72 older coal ash dumps at 22 power plant sites in Indiana for the first time, under the safeguards established by the 2024 Legacy Coal Ash Rule. Those dump sites are in addition to 42 coal ash ponds (all but one of which have no protective liner to prevent leaks of hazardous chemicals) and 9 landfills that were covered by the 2015 Rule. In total, all these ash dumps contain more than 134 million cubic yards of toxic coal ash. That’s equivalent to a football field piled nearly 12 miles high with coal ash.
Groundwater contamination above federal safe drinking water standards was detected at every plant that provided monitoring results.
At Edwardsport, State Line Energy, Tanners Creek, and Warrick, utility companies failed to report on any coal ash ponds covered either by the 2024 or the 2015 Rule, which is potentially in violation of federal law. Earthjustice estimates there may be nine coal ash ponds at these four power plant sites.
For More Information
Christine Santillana, Senior Legislative Counsel, Earthjustice, csantillana@earthjustice.org
Lisa Evans, Senior Counsel, Earthjustice, levans@earthjustice.org.
About the Map
- EPA’s first coal ash regulations, issued in 2015, covered only some coal ash dumps, exempting older ponds and landfills at current and former coal plant sites.
- In 2024, EPA extended federal monitoring and cleanup requirements to hundreds of previously excluded older coal ash landfills and ponds leaking toxic pollution into groundwater and surface water. Industry is now required to monitor those older dump sites, filing initial reports on so-called ‘legacy’ ponds at former coal plants in 2024.
- In 2026, industry will be required to report on additional dump sites at operating power plants that did not receive ash after Oct. 19, 2015. Groundwater monitoring requirements are not yet in effect for these newly regulated dumps, so the table below may lack specific information about the number of units and the extent of contamination at a particular site.
More on Coal Ash in Indiana
- Poisonous Coverup: The Widespread Failure of the Power Industry to Clean Up Coal Ash Dumps (November 3, 2022)
- Cleaning Up Coal Ash For Good: Resources and Recommendations (July 8, 2021)
- Other states are making utilities dig up toxic coal ash. Indiana is letting it sit there. (February 10, 2021)
- Secrets in the Ash (December 14, 2018)
- New Tests Reveal 15 out of 15 of Indiana’s Coal Ash Sites Are Leaking (August 17, 2018)
- Groups to Sue to Compel Duke Energy to Stop Withholding Required Toxic Waste Spill Safety Information (September 20, 2017)
- Duke Energy Violates National Coal Ash Rule by Hiding Critical Dam Safety Information (September 20, 2017)
Coal Ash in States, Territories, Regions
Puerto Rico (En Español)
Earthjustice fights in the courts for a long-term solution to the toxic menace of coal ash. And we act on behalf of dozens of clients and over 100 coalition partners to defeat legislative attempts to subvert federally enforceable safeguards of coal ash.
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