Best Management Practices for Coal Ash Ponds

Angela Neville, JD

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The unfortunate coal ash spill at the Tennessee Valley Authority’s (TVA’s) Kingston Fossil Plant that occurred on December 22 has heightened national awareness of the problems associated with utilities’ coal ash surface impoundments if they are not properly maintained.

Regulations governing coal combustion waste disposal vary considerably from state to state.

At this time there are no national standards governing the maintenance of coal ash surface impoundments and their retention dikes. The U.S. Environmental Protection Agency (EPA) does not consider the waste "hazardous." Some environmental groups, including the Environmental Integrity Project, argue that even though coal ash is characterized as nonhazardous waste by the EPA, the waste at some facilities has been found to contain harmful metals such as lead and arsenic. In contrast, industry groups have been quick to respond to complaints about the lack of appropriate regulation of coal ash surface impoundments (see sidebar, "Kingston’s King-size Mess").

Kingston’s King-size Mess

The ash reservoir rupture that occurred in the early morning hours of December 22, 2008, at Tennessee Valley Authority’s (TVA’s) Kingston Plant released 5.4 million cubic yards of wet coal ash into two sloughs that flow into the Emory River (Figures 1 and 2). The dike rupture certainly qualifies as a terrible accident and a black eye for TVA’s reputation that will take years to heal. TVA’s maintenance and inspection practices will come under close scrutiny, and management will take some political heat. In the meantime, TVA has promised to remove the two million tons of ash waste and restore the affected areas.

1. Before. This aerial photograph of the Kingston Plant and surrounding areas was taken prior to the ash slide of December 22, 2008. Source: TVA

2. After. This photograph of the same area was taken on December 23, 2008, the day after the earthen containment walls holding more than five million cubic yards fly ash and bottom ash sludge failed. Source: TVA

However, laboratory analysis of the ash wastes debunks the many media reports that were released after the accident that characterized the break as a huge environmental disaster.

The same day as the break, the EPA’s contractor, Tetra Tech, was mobilized. It was the first of several labs to conduct soil and ash sampling of the affected areas. Samples were collected from the surface, a depth of 30 inches, and a vertical core at 52 feet across the flood area.

In sum, laboratory analysis of all the test samples found that the constituents, with one exception, were well below the EPA Region 4 Removal Action Levels (RALs) for residential soil, which are much stricter than industrial limits. In fact, ash testing by a certified, independent laboratory found that the ash constituents were on the order of 10 to 100 times less than the limits that would cause it to be classified as a hazardous waste by the EPA.

Arsenic was the only constituent found in several samples to be at concentrations above residential RALs, but the levels remained well below industrial limits. To put the numbers into their proper perspective, the arsenic concentrations, though above residential RALs, are still within the range of naturally occurring levels in Tennessee soils. Specifically, the arsenic levels were found to range from 45.8 ppm to 81.3 ppm. The residential and industrial RALs are 39 ppm and 177 ppm, respectively. Scotts Winterizer Fall Lawn Fertilizer used to green your yard in the spring has an arsenic concentration of around 57ppm.

"What’s been interesting to me is this fiction that since coal ash is not regulated by EPA as hazardous waste, there’s no regulation at all," said Jim Roewer, executive director of the Utility Solid Waste Activities Group in a recent press release. "That’s simply not true. Many states have very tough programs."

Edison Electric Institute spokesman Dan Riedinger, whose association represents several major U.S. utilities, said in a statement made in January that his group opposes a hazardous waste designation for coal ash but added, "It’s too early to rule out other options that can help utilities improve their management practices and provide the public with the reassurance it needs in the wake of TVA."

Regulations governing coal combustion waste disposal vary considerably from state to state. Some states do little, some require companies to obtain discharge permits, and others establish rigorous water monitoring rules. Many states also lack regulations governing the maintenance of the coal ash ponds.

Illinois is an example of a state with a regulatory program dealing with the maintenance of coal ash ponds. The Illinois Environmental Protection Agency has inspectors who scrutinize the ponds and landfills where coal ash waste is stored, according to an article published by The Southern Wire Services on January 15. However, despite the requirements, there are no regulations in place in Illinois that stipulate how frequently groundwater near the old, unlined ash ponds must be monitored. Instead, each site is monitored on a "case by case" basis, said Darin LeCrone, a manager in Illinois EPA’s bureau of water permit section.

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