US EPA

EPA announced the availability of the final report, The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields. This report assesses the state of the science on the environmental impacts of mountaintop mines and valley fills (MTM-VF) on streams in the central Appalachian coalfields. These coalfields cover about 48,000 square kilometers (122 million acres) in West Virginia, Kentucky, Virginia and Tennessee, USA. Our reviews focused on the impacts on mountaintop removal coal mining, which as its name suggests, involves removing all or some portion of the top of a mountain or ridge to expose and mine one or more coal seams. The excess overburden is disposed of in constructed fills in small valleys or hollows adjacent to the mining site.

Our conclusions, based on evidence from the peer-reviewed literature and from the U.S. Environmental Protection Agency's Programmatic Environmental Impact Statement released in 2005, are that mountaintop mines and valley fills lead directly to five principal alterations of stream ecosystems:

1. springs and ephemeral, intermittent and perennial streams are permanently lost with the removal of the mountain and from burial under fill,
2. concentrations of major chemical ions are persistently elevated downstream,
3. degraded water quality reaches levels that are acutely lethal to organisms in standard aquatic toxicity tests,
4. selenium concentrations are elevated, reaching concentrations that have caused toxic effects in fish and birds, and
5. macroinvertebrate and fish communities are consistently degraded.

This report reviews the state of the science on the environmental impacts of mountaintop mines and valley fills (MTM-VF) on streams in the central Appalachian coalfields. The coalfields cover about 12 million acres in West Virginia, Kentucky, Virginia, and Tennessee. The final report reviews literature relevant to evaluating six potential consequences of MTM-VF operations:

1. Loss of headwater resources;
2. Impacts on water quality;
3. Impacts from aquatic toxicity;
4. Impacts on aquatic ecosystems
5. Cumulative impacts of multiple mining operations; and
6. Effectiveness of on-site reclamation and mitigation activities.

The report reviews the impacts on terrestrial ecosystems from the narrow perspective of their effects on aquatic ecosystems. The review of reclamation and mitigation practices was limited to their effectiveness in improving on-site aquatic ecosystems. The report did not review the impacts of MTM-VF on cultural and aesthetic resources or human health. EPA used two primary sources of information for the evaluation: (1) the peer-reviewed, literature published up through December 2010 and (2) the Programmatic Environmental Impact Statement (PEIS) on Mountaintop Mining/Valley Fills in Appalachia and its associated appendices prepared in draft in 2003 and finalized in 2005.

This report assesses the state of the science on the environmental impacts of Mountaintop Mines and Valley Fills (MTM-VF) on streams in the Central Appalachian coalfields.

U.S. EPA. The Effects Of Mountaintop Mines And Valley Fills On Aquatic Ecosystems Of The Central Appalachian Coalfields (2011 Final). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/138F, 2011.