Selenium is a naturally-occurring
element that ends up in runoff from coal fly ash dumps and valley fills. In
small amounts, it is harmless, but some studies have found that it is toxic to
aquatic life and humans in larger amounts.
In most cases, power plants and coal mines haven’t installed
advanced technology to remove selenium from their runoff. Certain mines have
struggled to meet federal limits imposed over the past few years.
a federal judge ordered Patriot Coal to install a selenium-treatment system at
one of its mines. Massey Energy and
Arch Coal subsidiaries are scheduled to go to court over similar issues this
So far, American Electric Power’s Mountaineer Power Plant,
in Mason County,
is the only one in the state to install ABMet technology. “ABMet” stands for “Advanced
Biological Metals Removal.” AEP spokeswoman
Melissa McHenry says the system is necessary so the plant can comply with tightening
“Well there are actually new selenium limits that are
required by water regulations nationally that will go into place next year,”
she said. “Our Mountaineer plant would exceed those new limits, so we’re
installing the equipment to ensure we’re operating within the new selenium
ABMet technology is owned by General Electric. Tim Pickett
is the system’s inventor.
“It’s becoming more and more of a problem now with the coal
mining, and coal-fired power plants is a big market for us,” Pickett said.
That’s because power plant scrubbers, designed to remove
sulfur dioxide from the plant’s emissions, also usually end up scrubbing out
selenium. That selenium is often discharged in the plant’s wastewater.
But Pickett says technology like ABMet can remove selenium from
“Basically it’s a biological filter,” he said.
It uses a special kind of carbon enclosed in a tank. Water
flows through the tank.
“Now on this carbon are specific strains of bacteria that we
use that are selenium-reducing bacteria,” he said. “So they will reduce the
selenium as the water flows through this bed and precipitate the metals in the
bed and then the metal would stay in the bed, it’s retained in there.”
Pickett’s ABMet system isn’t the only option for selenium
removal. Derek Teaney is the senior attorney with the Appalachian Center for the Economy and the Environment, and has focused on selenium cases for several
years. He says biological treatments like ABMet, as well as others like reverse
osmosis are both legitimate ways to remove selenium from water. But there are
others Teaney calls “snake oils.”
“OK, there’s a chemical process by which we can remove
selenium by using iron,” Teaney said. “But when it comes time to engineer that,
to handle the flows that come out, it just simply doesn’t work consistently.
Yes, it may remove selenium from the water, but does it remove enough? Is it
going to do it consistently?”
ABMet and other biological selenium treatment systems
require frequent attention. Teaney says this is one reason he believes the coal
industry has been slow to adopt the technology.
“For decades they have been content with building a sediment
pond and letting whatever comes out of that pond be their version of water
treatment,” he said. “It’s just like everything else that you see with the coal
industry: they want to mechanize, and reduce the need for human labor and
expense, keep the price of coal down, and that’s why they’ve been loathe to
investigate real treatment for selenium, from my perspective.”
The ABMet system at the Mountaineer Power Plant will cost
$27 million to install—a cost that will eventually be borne by consumers.