Watershed Contamination from Metal and Uranium Mining
scientists collecting soil samples inside the perimeter fence at the Canyon Mine, Arizona. The mine's headframe and mine workshop are visible in the background. Photo Credit: Kit MacDonald, U.S. Forest Service.
Watersheds affected by active and/or abandoned hard rock mining (HRM) often have hundreds of mining-related sites with little information on their relative significance as sources of metals contamination and acid mine drainage. Furthermore, natural weathering of the geologic deposits, which are sought out for metal deposits, can be a source of contamination even in the absence of mining activities. The nature of such distributed natural and anthropogenic sources makes a traditional site by site cleanup approach grossly inefficient and likely ineffective.
A USGS scientist collects a water sample for analysis of mineral particles know as colloids. Toxic metals (such as copper in excess) bind to the particles, which are then ingested by aquatic animals. Photo credit: Daniel Cain, USGS
The overall goal of HRM research is to provide improved information and tools to support decisions related to management, risk assessment, remediation planning, and mitigation of the anthropogenic effects of mine drainage on the surrounding watersheds and ecosystems. The principal research objectives are to a) characterize hydrologic and biogeochemical processes that affect dispersal of metals and associated contaminants and b) describe contaminant pathways to organisms. Current research expands on previous Toxic Substances Hydrology (Toxics) Program hard rock research by including investigations across broader temporal and spatial scales and by integrating research on bioaccumulation and the effects of metal contamination on organisms with investigations on biogeochemical and hydrologic processes that affect transport and fate of metals in streams and near-stream ground-water systems. Two guiding principles of the research are (1) interdisciplinary coordination to integrate all factors and processes that control the affects of HRM on watersheds and ecosystems from source to receptors, and (2) synthesis of interdisciplinary knowledge across scales to make relevant to the practical management decision making, including liaison with land management agencies for technology transfer and effective identification of science needs.
Hard Rock Mining Related Science Feature Articles
Other Program Hard Rock Mining Research
Hard Rock Mining Research Publications
- Informing future decision-making on uranium mining--A coordinated approach to monitor and assess potential environmental impacts from uranium exploration and mining on federal lands in the Grand Canyon region, Arizona: Tillman, F.D., Hinck, J.E., Van Gosen, B.S., and Walton-Day, K., (IN PRESS).
- The precipitation of indium at elevated pH in a stream influenced by acid mine drainage: White, S.J.O., Hussain, F.A., Hemond, H.F., Sacco, S.A., Shine, J.P., Runkel, R.L., Walton-Day, K., and Kimball, B.A., 2017, Science of the Total Environment, v. 574, p. 1484-1491, doi:10.1016/j.scitotenv.2016.08.136.
- Geochemistry and hydrology of perched groundwater springs--Assessing elevated uranium concentrations at Pigeon Spring relative to nearby Pigeon Mine, Arizona (USA): Beisner, K.R., Paretti, N.V., Tillman, F.D., Naftz, D.L., Bills, D.J., Walton-Day, K., and Gallegos, T.J., 2016, Hydrogeology Journal, p. 1-18, doi:10.1007/s10040-016-1494-8 (Advanced Web release).
- Effects of flow regime on metal concentrations and the attainment of water quality standards in a remediated stream reach, Butte, Montana: Runkel, R.L., Kimball, B.A., Nimick, D.A., and Walton-Day, K., 2016, Environmental Science and Technology, doi:10.1021/acs.est.6b03190 (Advanced Web release).
- Use of mineral/solution equilibrium calculations to assess the potential for carnotite precipitation from groundwater in the Texas Panhandle, USA: Ranalli, A.J., and Yager, D.B., 2016, Applied Geochemistry, v. 73, p. 118-131, doi:10.1016/j.apgeochem.2016.08.004.
Links to other USGS Information on Hard Rock Mining Contamination