Coal mining has long been an important part of the Appalachian economy, and while efforts to find sustainable energy sources are ongoing, coal continues to be a major source of energy and jobs.
Regulatory concerns over the environmental impact of mining are leading researchers to develop new technologies to help mining companies minimize their impact on the environment, restore ecosystem processes on reclaimed mine sites, and still retain economic viability.
With help from a Wells Fargo Clean Technology and Innovation Grant, Virginia Tech researchers are testing a technology called electrical resistivity imaging (ERI) that has the potential to visualize near-surface hydrology and allow better-designed mining operations to manage water flows and quality.
"Electrical resistivity imaging will allow us to see inside the valley fills created by surface coal mining in a brand new way," said Erich Hester, assistant professor of civil and environmental Engineering within the College of Engineering at Virginia Tech. "This will allow us to better understand how water moves through the ground during storms and how it interacts with pollution-generating spoil rock."
Near-surface hydrology is the study of rainwater flow over, into, and through near-surface soil and geological materials. It is used to analyze the environmental impact of surface coal mining, which releases natural mineral constituents that have a negative impact on water resources and can increase the possibility of flooding in nearby streams.
These concerns can be addressed if mine reclamation practices can restore near-surface hydrology as closely as possible to pre-mining conditions.
The problem, however, is that restoring mining sites is often made difficult because water flowing beneath the surface is difficult to see or measure. ERI aims to change that. The technology sends brief electrical pulses into the ground, measures pulse transmissions to other locations, and creates maps of the electrical resistivity of soils and other geological materials. These maps can be used to determine water flow paths in multiple dimensions.
"This knowledge should eventually allow future mining operations to adjust fill placement techniques to reduce pollutant loading to streams, thereby helping restore the health of downstream aquatic ecosystems," said Hester, who is leading the research project along with Carl Zipper, a Virginia Tech professor of crop and soil environmental science within the College of Agriculture and Life Sciences.
In a recent release, Dee O’Donnell, regional president for western Virginia at Wells Fargo, explained why funding this particular research was appealing to her company:
"I am thrilled that Wells Fargo is able to support a project such as this one," she said. "The ERI technology that this grant supports could help reduce the environmental impacts, resulting in improved resources for the community, reduced treatment costs, and job creation, if the technology evolves and is widely adopted – which I have full confidence that it will be."