Toxic Coal Ash in Wyoming: Addressing Coal Plants’ Hazardous Legacy

For decades, utilities disposed of coal ash — the hazardous substance left after burning coal for energy — by dumping it in unlined ponds and landfills. Wyoming has 26 coal ash dumpsites.

Coal ash contains hazardous pollutants including arsenic, boron, cobalt, chromium, lead, lithium, mercury, molybdenum, radium, selenium, and other heavy metals, which have been linked to cancer, heart and thyroid disease, reproductive failure, and neurological harm.

Industry’s own data indicate that across the country 91% of coal plants are currently polluting groundwater above federal health standards with toxic pollutants.

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.

Despite EPA’s 2015 Coal Ash Rule, which created the first-ever safeguards for coal ash disposal, many coal ash dumps remain unregulated due to sweeping exemptions for legacy coal ash ponds and inactive landfills.

The exempted coal ash dumps are sited disproportionately in low-income communities and communities of color. The EPA issued a proposed rule to address most of these exemptions on May 17, 2023.

The Naughton Power Plant in Kemmerer, Wyoming,
The Naughton Power Plant in Kemmerer, Wyoming, in 2010. (Nancy Nehring / Getty Images)

Action Needed

The magnitude of harm from recklessly dumped toxic coal ash requires decisive action from federal and state regulators.

  • Utilities must be required to comply with the law and immediately clean up their pollution.
  • EPA and states must make enforcement a priority and act quickly to ensure that utilities leave communities with sites that benefit rather than harm their health, environment, and economic status.
  • EPA must swiftly strengthen the Coal Ash Rule to address the many legacy ponds and inactive landfills that are unregulated, and to prohibit coal ash used as fill unless protective measures are put in place, to ensure all Wyoming communities are protected from coal ash pollution.
Coal ash dump sites across the United States. Use this map to understand where coal ash might be stored near you and how a given site may be impacted by EPA's expansion of the federal Coal Ash Rule. (Caroline Weinberg / Earthjustice)

18 Regulated Coal Ash Disposal Sites in Wyoming

Wyoming utilities operate 18 federally regulated coal ash ponds and landfills containing more than 53 million cubic yards of toxic waste at four power plants.

Coal ash has caused groundwater contamination at all of Wyoming’s regulated dumpsites.

Some of these dumps are contaminating water at dozens or even hundreds of times the safe levels of certain pollutants.

Two of them, Naughton Power Plant and Jim Bridger Power Plant, are the 3rd and 4th most contaminated coal ash sites in the U.S., respectively.

Despite the serious and widespread water contamination, no Wyoming company, to date, has initiated a plant-wide cleanup to restore groundwater, despite the legal requirement to do so.

Dave Johnston Glen Rock PacifiCorp 1 lined pond, 1 unlined pond, 1 landfill Arsenic (x1), Boron (x4), Cadmium (x2), Cobalt (x3), Lead (x2), Lithium (x1), Molybdenum (x10), Sulfate (x2)
Jim Bridger Point of Rocks PacifiCorp 2 unlined ponds, 1 landfill Antimony (x1), Arsenic (x4), Boron (x9), Cadmium (x3), Cobalt (x92), Fluoride (x3), Lead (x4), Lithium (x164), Molybdenum (x10), Radium 226+228 (x2), Selenium (x85), Sulfate (x125), Thallium (x11)
Laramie River Wheatland Basin Electric Power Coop 5 unlined ponds, 1 landfill Boron (x2), Lithium (x3), Molybdenum (x5), Sulfate (x9)
Naughton Kemmerer PacifiCorp 2 lined ponds, 4 unlined ponds Antimony (x2), Arsenic (x10), Barium (x1), Beryllium (x2), Boron (x16), Cadmium (x2), Chromium (x3), Cobalt (x13), Lead (x16), Lithium (x242), Molybdenum (x3), Radium 226+228 (x1), Selenium (x150), Sulfate (x66), Thallium (x9)

All data on groundwater contamination from coal ash derived from the utilities’ publicly accessible CCR Compliance Data and Information websites, and exceedances were calculated by Environmental Integrity Project.

For more information on regulated coal ash sites in Wyoming, see Mapping the Coal Ash Contamination.

Eight Unregulated Coal Ash Legacy Ponds and Inactive Landfills in Wyoming (ash dumps exempted from the 2015 Coal Ash Rule)

In addition, Wyoming hosts at least eight unregulated inactive coal ash landfills and legacy ponds that escape federal regulation. The exact number remains unknown because utilities are not required to report these sites.

These dumps are almost certainly contaminating water and threatening health and the environment; however, monitoring data are not currently available for most unregulated sites.

As we anticipate EPA’s proposed rule on legacy ponds and unregulated landfills in May 2023, a concern remains that the agency will not address coal ash that was dumped off site or used as fill.

Jim Bridger Point of Rocks PacifiCorp 0 1 Yes – Industry data
Naughton Kemmerer PacifiCorp 0 1 Yes – Industry data
Osage Osage City of Osage 2 2 Unknown
Wyodak Gillette PacifiCorp 1 1 Unknown

These data were developed by using EPA datasets relied upon in their 2007 and 2014 CCR risk assessments (Human and Ecological Risk Assessment of Coal Combustion Residuals) and comparing those datasets to the universe of regulated units.

“Industry data”: All data on groundwater contamination from coal ash derived from the utilities’ publicly accessible CCR Compliance Data and Information websites, and exceedances were calculated by Environmental Integrity Project.

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.

Earthjustice’s Clean Energy Program uses the power of the law and the strength of partnership to accelerate the transition to 100% clean energy.