Coal-ash waste poses risk across the nation
Hundreds of landfills and slurry ponds – like the one that failed in Tennessee – are dotted across the US, endangering communities and water supplies.
The billion-gallon wave of toxic coal-ash sludge that burst from a power-plant retention pond and buried 300 acres of rural Tennessee hints at a far larger problem: hundreds of similar threats nationwide.Skip to next paragraph
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More than 1,300 coal-ash waste sites are dotted across the United States, about half of them actively used, federal data show. Some are landfills. The rest are “surface impoundments” (storage lagoons), which, like the one in Tennessee, mix ash with water.
Coal ash has some beneficial uses. It can be mixed with concrete to make roads, for example. But storing coal ash in a retention pond – common at coal-fired power plants nationwide – can be a threat to the environment and humans as well: The ash contains many toxic metals, including arsenic, lead, and chromium.
At least 67 coal-ash sites have been found to be damaging drinking-water supplies in communities across 23 states, the US Environmental Protection Agency reported last year. But those EPA-identified sites grossly understate the threat, environmentalists say.
EPA study finds only 13 'safe' coal-ash waste dumps
Among an additional 155 landfill and surface-impoundment sites in 36 states reviewed by the EPA in 2007, all but 13 had no liner or an inadequate clay liner. Most – two-thirds of them – had no liner at all. (An impermeable liner is needed to keep toxic metals from leaching from the ash into groundwater supplies.)
This concerns Kevin Madonna, who, with his law-firm partner, Robert F. Kennedy Jr., keeps a close eye on water-pollution issues. Using last year’s EPA data, Mr. Madonna cross-checked coal-ash lagoons and landfills that had either a clay liner or no liner to see which ones were close to human populations and waterways.
One-third are close to human populations
Of the 155 waste sites, more than one-third were close or very close to significant human populations; two-thirds were near or very near key waterways, Madonna found. About half of the sites were coal-ash surface impoundments (lagoons).
“You have toxic wastes leaking into water bodies from probably every single one of these lagoons,” Madonna says. “It’s a huge mess.”
Little is known about coal-ash storage sites, which are lightly regulated by states and exempt from federal hazardous-waste regulations. Many are decades old, which increases the potential for leakage and containment failure, experts and environmentalists say.
Lisa Evans, an attorney for Earthjustice, an environmental group, says the EPA underestimates the problem. “Most impoundments are not monitored at all,” she says. “The list of sites identified by the EPA in 2007 is far from comprehensive.”
Needed: impermeable liners for waste sites
An earlier EPA report to Congress in 1999 showed that about three-quarters of some 300 active surface impoundment sites were unlined, Ms. Evans says. Of those that were lined, most were probably lined with clay, which is an inadequate barrier to toxic metals and invites contamination oflocal ground water, says Charles Norris. Mr. Norris is head of Geo-Hydro Inc., a Denver-based consulting company that has analyzed the hydrogeology of such structures. An impermeable composite (plastic) liner is what’s required, he and others say.