The Long Dark Shadow of Coal: Acid Mine Drainage in Kempton

Sep 30, 2019 1:30 PM

By Robert Spahr ‘13

Like many American coal towns, Kempton boomed and busted decades before the Surface Mining Control and Reclamation Act of 1977 began regulating active and abandoned coal mines to protect the environment.

One ridge north of the Kempton excavation, the town’s long-abandoned reason for existing still shapes the ecological health of Laurel Run, a tributary of the North Branch of the Potomac River. Every year, an equipment borehole and an airshaft from the mine discharge about a billion gallons of acid mine drainage.

“The borehole constantly flows at a pretty regular rate because of the diameter of the orifice,” said Dr. Jonathan Flood. “The larger orifice is the airshaft. It’s one of the first things you see and what Maryland’s Department of the Environment is actively treating. That flow fluctuates seasonally. Right now its discharge is really high because we’ve had a rainy year. Every time we’ve gone out, the pH is between 3.1 and 3.3.” The pH of pure water is seven.

Each semester, Flood has his students brainstorm remediation strategies. They test their proposals in small-scale on campus and around Western Maryland. Numerous research projects have been presented at Frostburg’s annual Undergraduate Research Symposiums, exploring various strategies to affordably raise the alkalinity of acid mine drainage to a more neutral pH – somewhere between six and eight.

“So far, those haven’t quite materialized,” said Flood. “Everything has a negative consequence that we wouldn’t want to play out at a landscape scale.”

The current treatment regimen partially raises the pH, removing iron and aluminum as sludgy deposits that stain the streambeds and banks, leaving traces of more hazardous contaminants in suspension.

“In that matrix of low-pH water, metals will stay in solution and travel. Those are metals like arsenic, thallium, cadmium, cesium – a lot of trace metals love low pH,” said Flood. “Those metals are traveling pretty far downstream when they should be locked into the carbonate mineral matrix of the coal.”

Instead, that pollution disrupts the delicate balance of a once-vibrant ecosystem.

“The incredibly low pH dissolves the carcasses of the benthic organisms that should provide the base for the broader ecosystem.

Laurel Run is lost,” said Flood. “Once the acid mine drainage hits, you don’t see benthic bugs. It creates an impoverished ecosystem where you should have these ‘Stories of the Serengeti’ predator-prey relationships with big trout coming in to eat them. That’s heartbreaking to begin with.”

Those predatory creatures seek out more bountiful waters, leaving Laurel Run barren. Though the polluted waters won’t hurt people instantly, they aren’t healthy.

“For us, you have this plume of trace metals that by themselves might not make you so upset,” said Flood, “but if you spend a lifetime drinking a little bit of arsenic every day, that could end up being a pretty big deal!”

Complicating matters, although Kempton’s acid mine drainage runs into Maryland, the contamination largely originates elsewhere.

“For an interstate problem, you can see Maryland is getting the short end of the stick,” Flood said. “The mine complex itself is really under West Virginia, but the drain is unfortunately in Maryland.”

Vexingly, Flood says Kempton’s acid mine drainage could be completely fixed.

“About four miles away, Mettiki is still operating a deep mine. They have a plant that removes the metal, raises the pH and discharges good water, but it costs money,” he said. “So far, out here we’ve had very temporary, halfway solutions. A dam like Jennings Randolph or a water treatment plant would fix the problem completely. … Or maybe Mettiki could be subsidized to treat Kempton’s water.”

In addition to the project’s educational benefits, Flood hopes the increased visibility of the problem will inspire a call to action among citizens, business and government to address the environmental damage in Laurel Run and the North Branch of the Potomac.

“There’s certainly a distance decay. It’d be nice to be able to say that people down at the lower reaches of the Potomac notice the impact of the Laurel Run discharge directly, but no,” said Flood. “But they are getting an indirect effect. The healthier the streams are up here, the better the water coming from upstream, the better their water is going to be there.”