Effects of Abandoned Coal Mine Drainage in the New River Gorge

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By Virginia and West Virginia Water Science Center October 31, 2024

Many abandoned historic mines surround the New River Gorge. Untreated water draining from these mines has the potential to alter the temperature and water quality of nearby creeks and rivers. Remediation and restoration has been proposed for many of these abandoned mines. However, the cold water seeping out of these mines may also create wetland areas along the flat mine benches which were cut into the hillslope. These wetlands and small streams could potentially be used as habitat by some species.

Before remediation and restoration begins, the USGS will be collecting data on the water-quality, hydrology, and ecology of areas affected by abandoned-coal-mine drainage to understand what possible impacts, both positive and negative, this drainage is having on the surrounding environment.

Background

A mountain creek in autumn — Keeney Creek is a tributary of the New River, and is one of the creeks potentially impacted by uncontrolled mine drainage in the New River Gorge.

The New River Gorge has a long history of coal mining. The steep walls of the Gorge provided easy access to multiple exposed coal seams, leading to establishment of many coal mines, as well as coal camps and towns that supported the mines. Many of the mining operations ended before significant environmental regulations existed, and the mine works were abandoned, usually without any reclamation or other efforts to reduce the environmental effects of the abandoned mine works.

These abandoned mine works are an important part of the history of coal mining in Central Appalachia. They also pose a problem: uncontrolled, untreated mine drainage flows from many of these sites. The southern portion of the Central Appalachian Coal basin, where the New River Gorge is located, is less likely to produce the type of bright orange acidic mine drainage that is so often a concern. However, mine drainage of any kind can alter the physical and chemical nature of the streams it flows into.

The water quality and volume of mine drainage in the New River Gorge, which commonly occurs as either discharges from mine portals or as seeps coal seam outcrops, is largely unknown. Planned mine reclamations will divert this mine drainage away from sensitive park infrastructure in several areas. However, this diversion of mine drainage may have both positive and negative effects.

Potential Positive Impacts of Mine Reclamation:

A tiny salamander in a scientist's hands — A salamander found during a synoptic habitat survey in New River Gorge. Salamander populations could be impacted by both water quality changed due to uncontrolled mine drainage and by the loss of wetland habitat.

Most of the surface waters in the Appalachian Plateaus have low conductivity and low concentrations of metals and trace elements. In contrast, mine drainage typically had high conductivity with elevated metal and trace-element concentrations. Mine drainage may alter the chemistry of streams that it flows into and potentially negatively affect stream communities. This effect would likely be most pronounced during periods of low flow, when the near constant inputs of mine drainage will represent a greater proportion of stream flow. Mine reclamation could protect streams from these water quality impacts.

Potential Negative Impacts of Mine Reclamation:

Upland Burrowing Crayfish (Cambarus dubius) — *Cambarus* aff. *dubius*, the Upland Burrowing Crayfish, one of the species of interest in this study.

Mine seeps discharging onto mine benches have created wetland habitats, rare in the Gorge. This wetland habitat may be attracting and supporting wetland-dependent species, including salamanders, burrowing crayfish, and other invertebrates. Diverting waters will dry the seeps and the wetlands they created, in turn reducing available wetland habitats for wetland-dependent species. In addition, the terrestrial salamander community may be disturbed during restoration and reclamation.

Study Objectives

This project seeks to provide information on the water-quality, hydrology, and ecology in areas of the New River Gorge National Park and Preserve affected by abandoned-coal-mine drainage. The primary focus of this study will be to document conditions at areas affected by mine-drainage prior to planned reclamation and restoration activities. Specifically, the USGS will:

Small stonefly nymph perched on a scientist's hand — A stonefly nymph found while sampling for benthic macroinvertibrates in the New River Gorge.

Conduct intensive water-quality monitoring at mine discharges, seeps, and streams within the Gorge to characterize seasonal patterns in water-quality and discharge,
Conduct a synoptic survey of water-quality and benthic macroinvertebrates at mine discharge and stream sites representing a gradient mine-discharge influences and minimally impacted stream sites to discern patterns across the gradient of disturbance,
Describe the physical and chemical geology of the coal seams and surrounding rock formations to provide insight into the hydrology and water quality of mine discharges,
Assess the benthic macroinvertebrate assemblages in mine discharges, seeps, and streams and relate assemblage structure to environmental settings,
Determine the occurrence and distribution of amphibian populations in mine-discharge affected areas,
Conduct a survey of burrowing crayfish occurrence in mine-seep wetlands.