US EPA

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. Our review focused on the aquatic impacts of 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. MTM-VF lead directly to five principal alterations of stream ecosystems: (1) springs, intermittent streams, and small 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 standard laboratory test organisms, (4) selenium concentrations are elevated, reaching concentrations that have caused toxic effects in fish and birds and (5) macroinvertebrate and fish communities are consistently and significantly degraded.

This report "The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields," reviews the state of the science on the ecological impacts of Mountaintop Mines and Valley Fills (MTM-VF) on streams in the Central Appalachian Coal Basin. This basin covers about 12 million acres in West Virginia, Kentucky, Virginia, and Tennessee. The draft report reviews literature relevant to evaluating five potential consequences of MTM-VF operations: 1) impacts on headwater streams; 2) impacts on downstream water quality; 3) impacts on stream ecosystems; 4) the cumulative impacts of multiple mining operations; and 5) effectiveness of mining reclamation and mitigation. 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, published literature 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. The draft report will be externally peer reviewed by EPA's Science Advisory Board in early 2010.

Following the external peer review, the document will be revised and published as a final report.

U.S. EPA. The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/138A, 2010.

Comments on this report may be submitted and reviewed using the e-Government Regulations.gov Web site. From the site, select Environmental Protection Agency and the keyword EPA-HQ-ORD-2009-0934 (for the docket ID) to comment on this report.