A stream in Southwest Indiana, about forty miles southeast of Terre Haute, flows with orange and turquoise-tinted water. The stream’s banks are a deep orange.
It’s deceptively beautiful.
“I hate to say it myself but it really is quite impressive,” says Mark Stacy, an environmental specialist for the abandoned Indiana mine lands program, as he walks along side of the stream.
Stacy is in charge of determining the impacts abandoned mines have on the environment.
“This is where the water is actually coming out of the old underground mine works themselves,” he says as he points to a pool of water where, if you look very closely, you can see water bubbling up from under the ground. “This whole area to the north and west has been mined.”
How Mines Can Contaminate Ground Water
As water flows through the mines, it can collect large amounts of harmful chemicals. The color in the stream comes from iron. When iron is exposed to the air, it oxidizes and turns the water a red-orange tint.
“The same thing happens in people’s homes when they have iron, maybe not as much as you see here, but when you have iron in your well, you notice it in the fixtures,” says Indiana Geological Survey geochemist Tracy Brannam as he stands on the banks of the stream. “Your bathtub starts to get an orange ring around it.”
If the iron content is too high, the water can be toxic, and it can contaminate other water sources.
A short walk downstream from the source, the water combines with another stream.
On this day, the second stream is covered with ice, but you can still tell it’s a much clearer color than the orange stream. It looks cleaner.
But when the two streams combine, they still have an orange tint. The water from the underground mine has contaminated both water sources.
How Water In Underground Mines Could Be Used
But scientists at the Indiana Geological Survey say the source of all this contaminated water is still a potential resource.
A report Tracy Brannam and his colleague Denver Harper recently released indicates there’s enough water sitting in Indiana’s abandoned underground mines to fill Lake Monroe three times.
But the quality varies widely and much of the water is like the orange stream—too contaminated to drink
There are other potential uses though, such as geothermal energy.
“You drill wells into these void spaces that fill with water and you circulate the water through and you have heat exchanges on the surface and you’re able to use it to some extent for heating buildings or cooling them in the summer,” Harper says.
The small amount of water that is clean enough to drink tends to be in older mines where the water has gone through a natural cleansing process.
The DNR and mining companies are trying to replicate that process to make it faster.
A site just a short drive away from the orange stream used to be a large mining operation. The DNR has since reclaimed the land—planting grass and trees over piles of mining refuse.
The DNR has also created an elaborate water system that allows the water to be naturally cleaned before flowing into other streams and water sources.
Before the state grants any company a mining permit, the business must first set aside money that will be used to return the mining areas to their natural state once the mining work is complete.
But that still takes years, and because Indiana has plenty of water resources right now, it’s not economically viable for private companies or cities and towns to clean up the water for their own use.
Decades down the road though, that could change.
“As we all know, on a global scale, water is becoming increasingly a problem, so those areas with adequate water resources are going to be at an economic advantage to places lacking water,” Harper says.