The Wetlands at UVa-Wise

Transforming an Environmental Liability into a Community Asset

Abandoned Mine Drainage and Wetlands

What is AMD?

Abandoned Mine Drainage occurs when minerals (pyrite and other metal compounds) left over from coal mining operations are exposed to water and oxygen. Pyrite is dissolved when water enters the old mining sites. When exposed to oxygen, pyrite forms iron oxide and acidity which flow out to nearby streams, polluting them with a heavy orange sediment and often acidic water.

The orange iron oxide sediment of AMD can coat stream beds, covering habitat for creatures and clouding the water.

Treating AMD

AMD can be treated in two ways: using chemicals to neutralize the water and reduce sediment, or using a passive wetlands system to clean the water before it goes downstream. Chemical treatments are often expensive and need monitoring and maintenance, but wetlands are ideal for abandoned mining sites. They also create great habitats and spaces for community members to enjoy!

How The Wetlands at UVa-Wise Work

On the UVa-Wise campus, AMD seeps out from four spots and into The Wetlands system. At the head of the stream where the first AMD seep is located, a K-dam was built to aerate the water and encourage the precipitation of the iron-oxide sediment.

The water then flows into a series of four settling ponds with limestone channels connecting them. The limestone channels help to neutralize the water, and the sediment sticks to the rocks as the water flows down into the next pond.

Native wetland plants in the ponds help to keep the sediment from flowing downstream into the other ponds and ultimately to the Guest and Clinch Rivers. These plants also take up some of the heavy metals still dissolved in the water.