“Everywhere coal is mined — however it’s mined — something is left behind. At surface mines, where huge machinery strips away the top layers of the earth, the coal is separated from the surrounding rock and what remains are piles of refuse. Known as tailings or slag (or, more colloquially, culm or gob), the loose rubble is saturated with toxins and heavy metals. With each rain, more and more of the contaminants leach into the soil and nearby waterways.
In underground mines, removing the coal leaves other minerals exposed. This is especially problematic in places like southeastern Ohio, where there’s a lot of what Natalie Kruse Daniels, professor and director of the environmental studies program at Ohio University, calls “sulfur coal.”
“Primarily what we find is pyrite — something that most people recognize as ‘fool’s gold,’” she says. “As it’s exposed to oxygen and water, that sulfide weathers and it produces acid and a lot of iron.”
That’s what is happening below the ground at the Truetown Discharge. The mine was abandoned and sealed in 1964 with the coal gone and sulfide minerals like pyrite left behind. It filled up, either with rainwater, groundwater, captured surface water, or a combination. In 1984, mounting pressure forced open the seal and the acid brew burst forth, carrying 6,000 pounds of iron oxide — basically, rust — out into Sunday Creek every day.
“The best estimate we have on this is that it will continue discharging for at least 600 to 800 years,” says Michelle Shively MacIver. She began working with Rural Action as the Sunday Creek Watershed Coordinator more than a decade ago. Today, she’s the director of project development at True Pigments.
The iron oxide is heavy, MacIver explains, and at Sunday Creek it precipitates out of the water fairly quickly, building up in thick, rough-looking scales along the creek bed and the shore. “The biggest problem the iron poses is it covers the entire bottom, and it just suffocates a healthy aquatic system,” she says.”
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“The iron build-up is only half the problem. The other byproduct inside the mine is sulfuric acid, which lowers the water’s pH too much for almost anything beyond some algae to thrive.”
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“Acid mine drainage can also worsen flooding, as build-up narrows streams and creeks and reduces their capacity for floodwater.”