Coming Clean: What the EPA Knows About the Dangers of Coal Ash

The report analyzes the EPA's 2007 risk assessment, finding that unlined coal ash ponds and landfills pose severe cancer and non-cancer risks to humans and aquatic ecosystems. It specifically highlights that residents near unlined ponds mixing ash and coal refuse face a 1 in 50 cancer risk from arsenic, 2,000 times the EPA's regulatory goal. The document also notes that boron levels in surface waters can reach 2,000 times safe thresholds for aquatic life. It argues that the EPA underestimated these risks by ignoring direct surface water releases and inhalation pathways, and calls for the phase-out of ash ponds within five years and the mandatory use of composite liners for landfills.

• Unlined surface impoundments (wet ponds) that mix coal combustion waste with coal refuse present the highest human health risks, with a predicted lifetime cancer risk of 1 in 50 for nearby residents due to arsenic leaching into drinking water. This risk is 2,000 times the EPA's regulatory goal of one additional cancer per 100,000 people.
• Unlined coal ash ponds cause non-cancer health risks by exposing residents to toxic metals above safe levels. Lead exposures can reach 9 times the federal maximum contaminant level (MCL), while cadmium and cobalt exposures can reach 9 times and 8 times their respective hazard quotients (HQ), potentially causing kidney disease, fragile bones, and heart or lung damage.
• Coal ash disposal poses extreme risks to aquatic ecosystems. Boron is predicted to leak into surface waters at concentrations up to 2,000 times the safe hazard quotient for aquatic biota. Additionally, lead in surface waters can reach 20 times the HQ for river otters, and lead in sediments can reach 200 times the harmless threshold.
• While landfills are generally predicted to be less risky than ponds, unlined landfills still pose a cancer risk from arsenic that is 50 times the EPA's regulatory goals. Some 'dry landfills' have already caused documented drinking water contamination, such as a site in Anne Arundel County, Maryland, and a Superfund site in northern Indiana.
• The EPA's 2007 risk assessment likely underestimated actual risks because it failed to account for several critical factors: direct releases to surface water (including unpermitted discharges), inhalation pathways, the interaction of pollutants, and the likelihood of liner failure.
• The use of composite liners—combining plastic membranes with clay—significantly reduces the risk of toxins leaking into groundwater. The report recommends that these liners be required for all dry landfills along with leak detection systems.

APA

Schaeffer, E., Evans, L., & Widawsky, L. (2009). Coming Clean: What the EPA Knows About the Dangers of Coal Ash. Earthjustice. https://earthjustice.org/sites/default/files/library/reports/final-coming-clean-ejeip-report-20090507.pdf

Chicago

Schaeffer, Eric, Lisa Evans, and Lisa Widawsky. Coming Clean: What the EPA Knows About the Dangers of Coal Ash. Earthjustice, 2009. https://earthjustice.org/sites/default/files/library/reports/final-coming-clean-ejeip-report-20090507.pdf.

Wikipedia

{{cite report |last1=Schaeffer |first1=Eric |last2=Evans |first2=Lisa |last3=Widawsky |first3=Lisa |title=Coming Clean: What the EPA Knows About the Dangers of Coal Ash |publisher=Earthjustice |date=May 2009 |url=https://earthjustice.org/sites/default/files/library/reports/final-coming-clean-ejeip-report-20090507.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{schaeffer2009coming, author = {Schaeffer, Eric and Evans, Lisa and Widawsky, Lisa}, title = {{Coming Clean: What the EPA Knows About the Dangers of Coal Ash}}, institution = {Earthjustice}, year = {2009}, month = may, url = {https://earthjustice.org/sites/default/files/library/reports/final-coming-clean-ejeip-report-20090507.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }