Coal ash is the toxic waste formed from burning coal in power plants to make electricity. The second largest industrial waste stream in the U.S., coal ash is linked to the country's four leading causes of death: heart disease, cancer, respiratory diseases and stroke.
Hundreds of contaminated sites and spills have been documented among the 1,400+ coal ash waste dumps across the country.
Contamination & spills (Known* cases). Coal combustion waste sites have contaminated groundwater, wetlands, and rivers.
High (81 dams) & Significant (250 dams) hazard coal ash ponds. The hazard ratings refer to the potential for loss of life or damage if there is a dam failure.

Spotlight State Fact Sheets:
Last updated: March 24, 2015.
Looking for exact coordinates? Locate on the larger maps: Contaminated Sites & Spills and High & Significant Hazard Dams
About the Contaminated Sites & Spills
* The 208 known cases of documented water contamination are likely to be only a small percentage of the coal ash-contaminated sites in the United States (last updated: February 2014). Most coal ash landfills and ponds do not conduct monitoring, so the majority of water contamination goes undetected.
According to U.S. EPA, there are over 1,000 operating coal ash landfills and ponds and many hundreds of "retired" coal ash disposal sites.
Contamination of groundwater, wetlands, creeks, or rivers could easily have been prevented with sensible safeguards such as phasing out leak-prone ash ponds and requiring the use of synthetic liners and leachate collection systems. Yet, ash and other coal combustion wastes are not subject to federal regulations that require these simple safeguards.
View contaminated sites & spills on a larger map.
Source documentation:
- EIP 12/2011 refers to Risky Business: Coal Ash Threatens America's Groundwater Resources at 19 More Sites (EIP; 2011).
- EIP 2/2010 refers to Out of Control: Mounting Damages from Coal Ash Waste Sites (EIP and Earthjustice; 2010).
- EIP 8/2010 refers to In Harm's Way: Lack of Federal Coal Ash Regulations Endangers Americans and their Environment (EIP, Earthjustice, Sierra Club; 2010).
- EPA 2007 refers to Coal Combustion Waste Damage Case Assessments (U.S. EPA; 7/9/2007).
- EPA 2013 refers to Environmental Assessment for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (U.S. EPA; 4/2013).
- EPA Database refers to Information Request Responses from Electric Utilities (U.S. EPA; 1/13/2012. Follow link to Database Results [Excel]).
- EPA ICR Data 3/2012 refers to EPA Office of Water data showing MCL [Maximum Contaminant Level] / state standard exceedances.
- EPA Superfund Response refers to Eden NC Coal Ash Spill, Regional IV, NRC#: 1073018.
- Groundwater Monitoring Data refers to individual websites hosting compliance data and information required by the U.S. EPA's Disposal of Coal Combustion Residuals Rule.
About the Hazard Dams
The U.S. EPA rates coal ash ponds according to a National Inventory of Dams criteria that categorizes the ponds by the damage that would occur in the event of a dam failure.
Coal ash dams are usually built from a combination of soil and ash and often impound millions of tons of toxic coal ash and wastewater. The majority are over 40 years old, and most do not have monitoring to detect leaks of toxic pollutants.
There are 331 High and Significant hazard coal ash ponds in the United States. (last updated: December 2014.)
View hazard dams on a larger map.
The NID hazard potential ratings refer to the potential for loss of life or damage if there is a dam failure:
- High / High* Hazard: Failure or mis-operation of these dams will probably cause loss of human life. (Designations of High* are based on state determinations. EPA considers the hazard potential of these dams to be Significant.)
- Significant Hazard: Failure or mis-operation of these dams results in no probable loss of human life, but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns.
For detailed information on the sites and state overviews, refer to the state fact sheets below.
For more information on coal ash ponds and landfills in the southeast, visit Southeast Coal Ash Waste, a website by Earthjustice's coalition partners at the Southern Alliance for Clean Energy.
How Safe is Your State?
In response to Freedom of Information Act requests filed by Earthjustice and our partners, the EPA has revealed the existence of more than 1,400 coal ash dump sites across the country. Fact sheets include detailed analysis based on data available and full citations for statistics. Download fact sheets: