There could be enough water sitting in Indiana’s abandoned underground mines to fill Lake Monroe three times, according to a new report from the Indiana Geological Survey.
Researchers estimate 172 billion gallons of untapped water is being held in the state’s underground mines, and the water in them is not like most of the state’s water that’s buried in porous rocks and difficult to extract.
“Within these underground mines, you actually do have free flowing pools of water, so you could actually withdraw quite a bit of water within a short period,” says Denver Harper, a retired coal geologist at the Indiana Geological Survey whose data was used in the report.
But researchers would also have to make sure there’s a way to replenish the water pools.
The water is also not likely clean enough for everyday use.
“There is water in these mines and it could be used for industrial purposes or some other purpose but as a direct groundwater source, It’s probably not a supply for drinking water purposes,” says Jack Wittman is a hydrogeologist at the geosciences and engineering consulting firm INTERA.
One of the biggest possible contaminants, Haper says, is sulfur. Indiana coal has a high concentration of sulfur, which has likely seeped into the water during the mining process.
Companies could clean the water, but doing so likely would not be economically viable while there are other water resources across the state that haven’t been used.
There is also the question of legal rights. Mining companies often still often own mineral rights on the property, which means they could have to sign off on any use of the water.
Wittman is putting together a comprehensive report of the state’s water resources for the Indiana State Chamber of Commerce. He plans to include the mine water in his analysis but says he would not consider it a major option until many years down the road.
However, Vince Griffin, Vice President of Energy and Environmental Policy for the Indiana Chamber of Commerce, says people who represent the mineral industry, including limestone quarry and coal companies, are being included in the discussion about how Indiana should manage its water resources.
Griffin also says the new sections of Interstate 69 from Evansville to Bloomington is increasing the demand for water resources along the route, which could exacerbate the need to utilize the water in the mines that are heavily concentrated in southwest Indiana.
“The aquifers in the southwestern part of the state and specifically along the I-69 corridor are very challenged to have good water supply, but if those coal mines are in that area, that level of water and the treatment of that water might become more of a possibility when you look at where you are going to go,” Griffin says.