In the study, the U.S. Geological Survey found that mining might reduce the size of rocks and other particles on stream-beds.
USGS scientists also found that mining could reduce daily fluctuations and seasonal variations in stream temperature.They also found that stream flows during low-flow periods could be six to seven times greater at sites with valley fills than those without fills.Those differences could spell problems for aquatic life, according to Doug Chambers, a USGS biologist who helped write the agency report.
"Changes in stream-bed particle sizes, low stream flows and stream temperatures that apparently result from mountaintop mining affect stream biological communities," Chambers said in a prepared statement."These changes alter the physical and chemical environment to which the biological communities are adapted," he said."Some species may not be able to adapt to the environmental changes, resulting in reduced numbers, or the local extinction of these populations."
Jeff Wiley, a USGS hydrologist, said that the study probably doesn't present the complete picture."A lack of high stream flows and insufficient elapsed time since mining may have prevented differences in stream channel characteristics from being identified in this study," Wiley said."Stream channel characteristics, such as width and depth, reflect runoff characteristics of the upstream watershed," Wiley said. "This study was conducted during 1999 and 2000, a period which included recent droughts, and was completed prior to the July 2001 flooding."The USGS review was conducted as part of a broad environmental impact study of mountaintop removal.In late 1998, the U.S. Environmental Protection Agency and other agencies agreed to conduct the study to resolve part of a federal court lawsuit over mountaintop removal.So far, the USGS report issued Tuesday is the only part of the federal study to be formally published by the government. Under the court settlement, the entire study was supposed to be completed by December 2000.Federal officials have not said when the rest of the broader study will be released - if ever.Because the USGS study was performed during a drought, and focused on how streams work during low-flow periods, the new report does not address mining's impact on flooding.But in a Tuesday news release, the USGS Charleston office said that it is working on that issue as well.Hugh Bevans, chief of the agency's West Virginia district, said that a new study being done with the U.S. Office of Surface Mining would investigate the effect of valley fills on high stream flows.The study will focus on six small watersheds that were affected by the July flooding in the headwaters of Clear Fork on Boone County, Bevans said.
A copy of the USGS report can be downloaded from the Gazette Online at http://wvgazette.com.To contact staff writer Ken Ward Jr., use e-mail or call 348-1702.