New EPA Testing Method Identifies Higher Coal Ash Threat; Must Drive Agency's Rulemaking

Arsenic, among others, leached at 1,800 times federal safe drinking water levels


Raviya Ismail, Earthjustice, (202) 667-4500, ext. 221 

A new testing method by the U.S. Environmental Protection Agency reveals that pollutants such as arsenic, antimony, chromium and selenium, can leach from coal ash at levels dozens and sometimes hundreds of times greater than the federal drinking water standard. This news comes on the heels of EPA’s proposal to regulate coal ash, in which the agency offered two options: a plan to regulate coal ash as hazardous waste and another to regulate it as non-hazardous.


According to EPA’s new testing data, cited in the agency’s proposed rule released yesterday, pollution from coal ash can shatter the "hazardous waste" threshold, an important factor as the EPA is facing pressure from industry to avoid defining coal ash as hazardous waste. The new testing procedure emphasizes the need for the EPA to make the right decision and choose the stronger of the two proposals for federally enforceable coal ash safeguards that use the strongest limits of the law to protect the communities living near coal ash sites.

In December 2009, the EPA produced a report examining the fate of pollution captured in smokestacks at coal-fired power pants. The report was quietly posted to the EPA’s website, but offered groundbreaking results. The EPA tested over 70 samples of ash and sludge from numerous power plants. The results revealed the potential for some ashes and sludges to release large concentrations of toxic chemicals. According to new testing methods on coal ash applied by the EPA’s Office of Research and Development:

  • Arsenic, a potent carcinogen, leached from one coal ash at 1,800 times the federal safe drinking water standard, more than 3 times the threshold of hazardous waste and over 76 times the level of previous leach tests;
  • Antimony, which causes heart, lung and stomach problems, leached from a coal ash at 1,800 times the federal safe drinking water standard and over 900 times the level of previous tests;
  • Chromium, which can cause cancer and stomach ailments, leached from one coal ash at a level 73 times the federal safe drinking water standard, over 1.5 times the hazardous waste threshold, and 124 times the level of previous leach tests; and
  • Selenium, which causes circulatory problems in humans and is a bioaccumulative toxin extremely deadly to fish, leached from one coal ash at nearly 600 times the federal drinking water standard, 29 times the hazardous waste threshold and nearly 66 times the level of previous leach tests.

"The writing is on the wall, the floor, the ceiling, everywhere," said Lisa Evans, senior administrative counsel at Earthjustice. "Coal ash pollution poses a significant threat to human health and our environment. The EPA’s new testing methods are much more precise and clearly determine that arsenic, selenium and other pollutants from some coal ashes pose a toxic threat to drinking water, fish and wildlife populations, and our health."

Adding air pollution controls to existing power plants is shifting toxic pollution from the smokestacks to the fly ash, FGD gypsum and other air pollution control residues commonly referred to collectively as "coal ash." Increased concentrations of toxic metals in coal ash increases the potential for them to leach into water.

Read an Earthjustice report summarizing the EPA’s findings 

"This new EPA report confirms just how significant the threat is to aquatic life," said A. Dennis Lemly, Research Professor of Biology at Wake Forest University. Dr. Lemly is an expert in aquatic toxicology of selenium. "It shows that selenium quickly moves into water, often at levels that are thousands of times greater than what is necessary to poison fish.  With this degree of contaminant mobility, concentration, and toxicity, coal combustion waste, or coal ash, is an extremely hazardous material."

These new testing methods show that arsenic can leach from coal ash at 3 times, chromium can leach over 1.5 times, and selenium can leach at 29 times the threshold of what is considered hazardous waste. For decades, the EPA, state agencies and industry relied on a 1990 leach test, known as the Toxicity Characteristic Leaching Procedure (TCLP), which often failed to accurately predict levels of pollutants leaching from coal ash. For years, the National Academy of Sciences and the EPA’s own Science Advisory Board questioned the reliance on such an inaccurate testing method for coal ash and explicitly recommended that EPA replace the old test. In 2006, the EPA itself acknowledged the need for a more accurate and sensitive test and began using an alternate framework. The new EPA proposed coal ash rule explicitly states that "a considerable body of evidence has emerged indicating that the TCLP alone is not a good predictor of the mobility of metals in CCRs under a variety of different conditions."

The EPA’s new test method provides a more accurate assessment of the potential of toxic chemicals to leach from the waste, showing that coal ash pollution is an obvious threat to drinking water and in some cases, far exceeds the thresholds for hazardous waste.

"Sound science should inform decision making," said Mary Fox, PhD, MPH, Assistant Professor at the Johns Hopkins Bloomberg School of Public Health. "Reliable scientific testing methods ensure the most accurate data are available to regulators when they set protective standards. The EPA’s new testing methods clearly show the threat coal ash poses to drinking water supplies and the communities that rely on them. These findings provide critical information for establishing coal ash waste management strategies that protect water supplies." 

"The new leaching data is cited in EPA’s proposed rule, and this should end, once and for all, the reliance on a test that has no scientific basis." Evans said. "The utility industry and coal ash reuse industries argue that coal ash is not hazardous waste, relying on obsolete testing methods that are nearly 20 years old. But there is new science now being used by the EPA that shows unequivocally that some ashes and sludges behave just like hazardous waste."

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