EHS Administration, Enforcement and Inspection

Coal Ash Impoundment Closures

A leaked EPA list reveals more than 160 unlined coal ash ponds across the United States are under investigation for closure.

Coal combustion residuals (CCR), or coal ash, which is a byproduct of power plants that burn coal, contain contaminants like arsenic, cadmium, and mercury.

According to EPA estimates, more than 140 million tons of coal ash is generated annually, making it the second-largest wastestream in the nation, with mining waste being the largest. Approximately one-third of CCR is disposed of in dry landfills, just under 40 percent is recycled, 5 percent is used to fill abandoned mines, and about 20 percent is mixed with water and disposed of in “ponds,” some of which are actually lake-size.

In the past, it was common industry practice to utilize unlined ponds with earthen walls, known as “surface impoundments,” to store the toxic sludge.

Any pond with earthen walls is subject to failure; the walls can erode or breach, flooding can send the pond’s contents to surrounding land, and the contents can leach into groundwater.

Coal ash pond ruptures are devastating to public health and the environment. In 2008 in Kingston, Tennessee, after an earthen wall on a 40-acre coal ash pond ruptured, more than a billion gallons of waste contaminated 2 rivers and covered 300 acres. The EPA reported water samples tested after the spill contained 149 times the allowable standard of arsenic in drinking waters and other dangerous elevated levels of toxic metals.

In 2015, the EPA finalized the Coal Ash Disposal Rule, which established technical requirements for landfills and surface impoundments under Subtitle D of the Resource Conservation and Recovery Act (RCRA). One of the primary purposes of the rule was to protect groundwater from contamination. It requires:

  • Groundwater monitoring around surface impoundments and landfills;
  • Liner requirements for new surface impoundments and landfills to protect groundwater;
  • Groundwater cleanup from coal ash contamination;
  • The closure of unlined surface impoundments that are polluting groundwater;
  • The closure of surface impoundments that fail to meet engineering and structural standards or are located too close to a drinking water source;
  • Restrictions on the location of new surface impoundments and landfills so they cannot be built in sensitive areas, such as wetlands and earthquake zones; and
  • Proper closure of all surface impoundments and landfills that will no longer receive CCRs.

In January 2022, the Biden EPA announced it would take new actions to protect groundwater from CCR contamination, which included:

  1. Proposing decisions on requests for extensions to the current deadline for initiating closure of unlined CCR surface impoundments,
  2.  Putting several facilities on notice regarding their obligations to comply with CCR regulations, and
  3. Laying out plans for future regulatory actions to ensure coal ash impoundments meet strong environmental and safety standards.

Federal regulations called for unlined surface impoundments to stop receiving new waste and begin closure by April 2021 and included a process for plants to apply for extensions to allow more time for closure.

In the January announcement, the EPA reported receiving 52 complete extension applications, 3 of which were denied due to “several potential deficiencies with groundwater monitoring, cleanup, and closure activities, including a lack of monitoring wells, improper monitoring techniques, faulty identification of other sources of groundwater contamination, and insufficient evaluations of clean-up technologies, which could prevent adequate groundwater cleanup.”

The EPA maintains its consistent position has been that surface impoundments and landfills cannot be closed in locations where CCRs are in contact with groundwater.

These new enforcement efforts have been met with legal actions.

In April 2022, the Utility Solid Waste Activities Group (USWAG), a utility, trade, and operating association, sued the EPA in the U.S. Court of Appeals for the District of Columbia Circuit.

“The group argues that EPA’s current interpretation of the 2015 coal ash rule is based on a revision that didn’t go through an appropriate notice and comment period, and that federal law allows for closure of coal ash ponds in place along with groundwater monitoring and corrective actions,” says Greenwire.

“We don’t think they followed the rules,” asserts Dan Chartier, executive director of the USWAG. “So, since 2017, we’ve disagreed or we’ve made it clear that closure in place, even when [coal ash] material is in contact with groundwater, is allowed and addressed under the rule.”

Thomas Cmar, an attorney associated with Earthjustice, says the 2015 rule specifically states coal ash ponds cannot be closed in place when groundwater is infiltrating the pond. “They’re claiming that because EPA was silent during the Trump years that somehow means the new EPA is not able to enforce the regulations,” he says in the Greenwire article.

Long-standing industry practice has been to close these ponds utilizing cap-in-place methods, which involve draining the surface water and capping the ponds, leaving the waste in place. This process is easy to implement and is a relatively low-cost process, although EPA regulations require monitoring of these sites virtually forever.

An Earthjustice analysis, Cleaning Up Coal Ash for Good, compared the benefits, cost, and direct job creation of thoroughly removing the toxic pollution (clean closure) with leaving the ash in place with a cap to cover it. The report analyzed three power plant locations and concluded, in each case, that “the job creation, economic activity, and environmental benefits are far greater for clean closure than for cap-in-place.”

Given the public outcry and the Biden administration’s unyielding position against closing CCR landfills and ponds where there is groundwater contact and considering the disastrous results when ponds fail, industry appears to be fighting a losing battle. In the long run, it appears it would be more cost-effective for industry to move to dry-lined storage rather than spending years engaged in costly legal battles. Companies desiring harmonious community relations should consider developing clean removal methods and safe recycling options.

Many “forward-thinking utilities recognize that their communities and increasingly-stringent standards require more than leaving coal ash in polluting pits and have moved their coal ash to dry lined storage — a requirement even for the storage of the household garbage … ,” says Utility Dive. “Storing any waste, much less coal ash, in a dry, lined landfill away from water is the most basic form of modern waste disposal options.”