A researcher from the U.S. Geological Survey inspects impacts of acid mine drainage at a Superfund site. (Credit: USGS, Crustal Geophysics and Geochemistry Science Center)
Ohio University professor Kelly Johnson often finds herself knee deep in streams. Net in hand, she leads her biology students through lessons about life in southern Ohio’s waterways -- and the lack thereof.
In healthy waters, Johnson and her students kick up streambeds to free large insects; they sweep mayflies and caddisflies into nets and pour hundreds out on the ground for examination.
But their adventure gets murkier in certain waterways where the toxic legacy of the coal-mining industry lives on.
Students expecting to see clean blue streams instead run into crunchy waters thick with rusty buildup. When the crust is broken, Johnson said, streams looks orange, like “orange juice [that] someone poured some milk in.”
These waters are colored by metals like iron and nickel that coat and suffocate streambeds in glittering layers. Frothy plumes of aluminum make up the creamy haze in the water column above. Conspicuously missing are living things.
“We’ll do a kick and we might get four or five living things in the net,” Johnson said. “These streams are biologically dead.”
“It all looks wrong,” Johnson added. “You know this is not normal.”
Thirty-two Ohio counties intersect the Appalachian Coal Basin, one of America’s largest coalfields. While many Midwestern mines ceased operation long ago, surrounding land and streams still feel their effects. Cascades of toxic waters seep daily from abandoned mines across the country and introduce leached metals and acidity into nearby streams, a process known as acid mine drainage (AMD). Throughout Ohio, 4,400 abandoned mines pollute at least 1,300 miles of once fresh water, threatening biodiversity and natural resources.
Scientists and activists claim that AMD is as damaging as it is little acknowledged. The EPA and USDA both recognize that AMD may present human health hazards, but confined to poorer rural areas, activists say it’s been difficult to attract dollars and ears to the issue.
Most animals aren’t adapted for influxes of AMD. Healthy streams support 30 to 40 species, but acidic streams are lucky to have any.
Some animals like the green sunfish and yellow perch can handle acidic waters, but that doesn’t mean they’ll survive them. Dissolved metals present other dangers.
When AMD meets a less acidic stream, metals within it precipitate out. They crust over the water while gilding and clogging streambed habitat.
“Even if (animals and insects) could tolerate the chemical stress, they have nowhere to sort of get down in and live and know where to feed,” Johnson said. Species sensitive to both AMD and habitat loss like mayflies, stoneflies, and caddisflies are the first to go and last to return.
Collectively, the impacts of AMD decay food webs -- and even hardy predators can’t survive.
It takes only minutes for acid mine drainage to infiltrate a stream, but getting rid of it is far more complicated.
“We can have an effect on the water quality of our streams, but it's not something that will ever go away,” said Marissa Geib, watershed coordinator for Huff Run Watershed Restoration Partnership in Mineral City, Ohio. “It was hard to swallow when I realized Huff Run is always going to be orange. There's no way that all of the dissolved metals will get out of the stream.”
AMD is an opened can of worms -- reactions among metals, water, and air are hard to stop.
“By and large, the most effective thing is to prevent the water from going into the mine to start with, or prevent the water from coming out of the mine,” Johnson said.
But plugging mines to keep out new water can increase pressure and force new seepages, and regrading surrounding land to drain water away is no mean feat. Teams neutralize AMD by dumping basic materials like limestone chips into shafts and streams, or by installing devices that treat drainage as it comes out.
Odds aside, a busy network of concerned parties is working to curb AMD. In Ohio, watershed groups like Geib’s work with the EPA and ODNR to acquire grant funding and complete remediation plans. Long-term monitoring -- cleaning valves, monitoring populations, and sampling water -- is left to volunteers, while ODNR engineers and contractors are in charge of project design and coordination.
Streams that receive help can see dramatic improvements. When Huff Run volunteers started treatment in the mid-1990s, the only species in the 9.9-mile stretch of stream was the resilient green sunfish. Since then they’ve found 22 species in the stream.
Together, Ohio remediation teams treat 10,886 pounds of acidity a day.
But remediation is trial and error. “We've looked at restoration options with acid mine drainage and I can honestly say we have not seen too much success,” said Thomas P. Simon, a professor of ichthyology at Indiana University.
“We just kind of compound the problem sometimes,” Simon added.
Extending responsibility for remediation to Ohioans all across the state has been challenging.
“This is ultimately a problem that's happening in Appalachian Ohio and oftentimes that doesn't get communicated up to Columbus,” said Ohio University professor Natalie Kruse, who teaches environmental studies courses about watershed management.
When problems are out of sight, they’re out of mind. But the thing about water is that it doesn't often stay in one place.
“Everyone is part of a watershed,” Geib said, “and all watersheds connect at some point.”
In the face of all this, activists and scientists focus on the good they can do and perceived risks of doing nothing.
“If you stop treating (AMD) and we just declare that these creeks are dead and that that's okay -- that it's okay that we kill creeks -- then that sets a very scary precedent to me,” Kruse said.