Toxic Cleanup: How to Clean a Coal Ash Pond

Toxic Cleanup: How to Clean a Coal Ash Pond

Coal ash pond cleanups have become a major environmental topic throughout the country lately, and lots of hazardous work on these sites has been taking place right here in Indiana. We’re going to take a dive into some of the nastiest details that we can dig up to keep our readers informed about what coal ash ponds are, why they’re so toxic, and what kinds of things are being done to rehabilitate these locations. So, get your boots on because we’re going to get dirty.


What is a Coal Ash Pond?

A coal ash pond is sometimes referred to by several names, such as an ash basin or surface impoundment. Basically, they’re a bit like a giant ashtray filled with the remains of coal that was burned by power plants to generate electricity. Typically, coal ash is stored in large open ponds until it dries out. Then it’s transported to landfills.

According to PBS, Indiana has about 86 coal ash ponds and 13 landfills – more than any other state. Most of the state’s ash ponds do not have a liner in place, meaning there is no barrier to prevent contaminants from leeching into the environment.

Coal provided about 58% of Indiana’s electricity net generation in 2021, according to the U.S. Energy Information Administration. That year, Indiana ranked third in the nation for total coal consumption.


Toxic Material

The reason that coal ash ponds are dangerous is because they are packed with hazardous and carcinogenic material. There are two main types of coal ash called bottom ash and fly ash, and both are stored in coal ash ponds.

Bottom ash is a solid that contains any non-combustible material that gets left behind after burning coal. This type of ash contains some really nasty stuff that is toxic to living things. You can find substances like arsenic, boron, cadmium, chromium, thallium, mercury, and quite a few other toxic chemicals in bottom ash. And worse yet, without proper containment this type of ash can get into the groundwater surrounding a disposal site and contaminate the area for years. In fact, groundwater contamination has been discovered around many of Indiana’s coal ash ponds.

Fly ash is a little different, but it contains many of the same toxic compounds. Instead of remaining as residual material after combustion, this type of ash goes up the flu and is captured by filtration equipment. Eventually, fly ash is disposed of in a similar manner to bottom ash, although some is recycled for use in concrete production a term called “beneficial use” by the EPA


How are these Ponds Cleaned Up?

Earlier this year, the U.S. Environmental Protection Agency ordered companies to stop dumping coal ash into unlined ponds and to accelerate their efforts to close ponds that are leaking or at risk for leaks. This presents a complex task for site remediation contractors. To learn more, Building Indiana connected with Hammond-based Griffin Dewatering, one of the Hoosier companies that specializes in removing the water that’s present in coal ash ponds. Griffin Dewatering has been working to rehabilitate coal ash sites in Indiana, Ohio, Iowa, Kentucky, Wisconsin, and North and South Carolina.

“The cleanup of a coal ash pond is a challenging, multi-step process, but it’s also very rewarding. Our company and our partners take a great deal of pride in making these sites much safer for the future. We follow very strict protocols for pollutant control, and the end result is a location that will be much cleaner and stable for the surrounding environment,” said Bill Abromitis, business development manager with Griffin Dewatering.

Coal ash ponds are typically cleaned in two ways. Sometimes a coal ash pond is cleaned up by digging out the ash and taking it to a landfill, and other times the ash is closed off or capped in place. Before excavation crews can come in to dig up a coal ash pond or bury it, all of the water in and around the pond has to be removed.

This is tricky because water can be found in several spots around these ponds. There is free water from sources like rain, groundwater that soaks into the pond from underneath, and additional water found in pores within the ash itself.

Griffin Dewatering installs pumps, filters, and deep wells to drain away the free water and groundwater. Then it uses shallower points to remove the excess moisture inside the ash. All of this water is then treated by specialized filtration systems to ensure safety and capture pollutants. Once the water is managed, the coal ash can either be dug out or capped in place by digging crews.

Image from Griffin Dewatering.


Commence the Cleanup

Efforts to remediate coal ash ponds are taking place in multiple locations across Indiana following the EPA’s new instructions. Cleanup efforts are underway, which has been a source of relief to many Hoosier residents throughout the state. And although there is still a long road ahead with billions of pounds of pollution to remove, each closed pond brings us closer to a cleaner, safer Indiana.

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