Coal Ash: EPA Can’t Decide If It’s Hazardous
by Bill Chameides | December 1st, 2010
posted by Erica Rowell (Editor)
A team of Duke scientists has tested the Emory River a dozen times for contaminants since a toxic sludge of coal ash was released into it from the Kingston Fossil Plant in December 2008. Nearly two years after the accident, contamination is still present.
While the government dithers, a new study documents potentially long-term contamination from coal ash.
The Coal Ash Saga
Time was, many Americans, myself included, knew little about coal ash. All that changed on December 22, 2008, when more than a billion gallons of coal waste broke through a dike at the Tennessee Valley Authority’s Kingston Fossil Plant and gushed into the Emory River and surrounding areas in Tennessee. (See details in the TVA’s Corrective Action Plan [pdf].) With the spotlight suddenly illuminating coal ash we learned that:
- Since 2001, the United States has produced more than 120 million short tons of coal waste annually;
- Roughly 60 percent of that waste is disposed of in some 600 impoundments (a k a ponds) and 300 landfills scattered around the country;
- Currently, of the 431 units checked so far, a number of the 49 surface ponds ranked as a “high hazard” have been in fair or poor condition. (Note that the dike that failed at the Kingston plant wouldn’t have made EPA’s “high hazard” list.)
We also discovered that other little informational tidbit about coal ash: there are no federal regulations on storing the stuff. While it’s well known that coal ash is loaded with toxic metals, EPA has yet to consider it a hazardous substance and so the regulation of its storage and disposal has been left up to the states. (Read more on the history of EPA’s non-regulation of coal ash.)
The New Regulatory Track: A Work in Progress
Following the Kingston spill, EPA Administrator Lisa Jackson promised swift action, pledging to pen a new rule on managing coal waste and hinting at revisiting the “hazardous” label by the end of 2009. Well, December 2009 came and went sans proposed rules.
In May 2010 EPA proposed two different tracks to regulate coal waste — hazardous or non-hazardous.
But here we are on the cusp of another December in pretty much the same boat as last year.
With the latest comment period on coal-waste regulation closing last month, industry and environmentalists are anticipating a final ruling, and, fearing the “worst,” outlets for the energy industry (including the Wall Street Journal) have already begun crying foul, predicting undue hardship if coal ash is labeled “hazardous.”
Kingston Spill ‘Remediated’
While all that’s been happening, the Kingston spill has conveniently and quietly withdrawn from the national spotlight.
Shortly after the spill, the TVA launched a dredging/cleanup operation to remove the coal ash and then sent much of it to a landfill in Alabama. By summer’s end, TVA’s CEO Tom Kilgore announced that dredging was complete, declaring, “We’ve got everything out of the river and it’s probably left better than it was before the spill.“
But Was the Cleanup Really Successful?
That’s a question my Duke colleagues Laura Ruhl, Avner Vengosh, and others decided to investigate.
View photos from testing expeditions.
They had gone to Tennessee immediately following the spill and documented high levels of contaminants like radioactive radium and arsenic in the spilled ash and arsenic in the affected waters of the Emory and the Clinch Rivers.
But they didn’t stop there. They returned to the area 11 more times between January 2009 and June 2010, collecting more than 220 samples of river water and the pore waters that lie in the sediments along the river bottoms. They published their results last week in Environmental Science & Technology. Their findings:
- There remain enhanced concentrations of contaminants such as arsenic downstream of the spill; however, the concentrations are below EPA’s safety thresholds for drinking water and environmental health.
- The amount of arsenic present varies with the river’s flow rate. The lower the river flow, the higher the arsenic concentration (presumably because there is less dilution). Under low-flow conditions, arsenic concentrations at some locations downstream of the spill were within a factor of three of EPA’s drinking water stand
- Much higher concentrations of arsenic existed in sampled pore waters as well as areas of the river with restricted water exchange. The pore-water concentrations were well above EPA standards, on average by more than a factor of 10.
The data indicate that, in spite of TVA’s dredging, significant amounts of coal ash remain in the sediments, and over time, contaminants like arsenic are leaching out of the ash and into the pore water and from there into the flowing river water.
In the authors’ words:
“the massive remediation efforts of TVA by dredging and removing over two million cubic meters of coal ash from the Emory and Clinch Rivers had only a minor effect on the river surface water quality. … Our data show that buried TVA ash that accumulated within the river bottom sediments … is highly reactive and generated high levels of dissolved [arsenic, boron, strontium, and barium] in the associated pore waters. [T]he presence of these elements in high concentrations in the pore water presents a potential direct threat to infaunal species that live in the subsurface.”
Don’t Drink the Water?
The waters from the Clinch and Emory Rivers eventually flow into the Tennessee River, a source of drinking water for lots of folks. Is the contamination from the ash spill cause for alarm for them? I suspect not. While nobody’s going to be happy to learn their drinking water is exposed to an ongoing source of contamination, by the time that water reaches their faucets, it appears that the arsenic from the coal ash will have been diluted manyfold.
While not as worrisome as drinking water contamination, the high concentrations of contaminants in pore water are of concern. Lots of critters at the bottom of the food web hang out in sediments.
The Spillover Into the Hazardous Waste Brouhaha
Contaminants like arsenic leaching out of coal ash at the bottom of the Emory and Clinch Rivers is one thing. But how do we know that these and other contaminants are not also leaching out of coal ash stored throughout the country? Quite possibly from a storage site near you? Isn’t this something EPA should be looking into as it finalizes its hazardous-waste ruling?
I am sure it is, but there’s a problem there. Ruhl and co-authors found that the procedure for toxicity leaching EPA uses to determine if a substance is a hazardous waste does not adequately cover the conditions under which coal-ash leaching occurs (in terms of acidity and abundance of oxygen). Ruhl et al conclude that EPA’s method “would underestimate the potential impact of coal ash leachate in many situations.”
The energy industry is unhappy over the prospect of coal ash being regulated, and when the energy industry cries foul, lots of folks in Washington probably listen. But I suspect there will be a pretty loud hue and cry when folks find out their waters are being spiked with arsenic from coal ash. Let’s hope EPA officials have time to read Environmental Science & Technology while fielding the barrage of attacks launched by the energy industry (see here, here, here and here).filed under: coal, energy, faculty, fossil fuels, pollution, waste, water
and: Alabama, arsenic, coal ash, contamination, energy industry, Environmental Protection Agency, fuel, hazardous waste, Kingston Fossil Power Plant, power plants, Tennessee, water pollution