Charles N Alpers

Biography

Since 1991, as a Research Chemist with USGS, Dr. Alpers has led numerous water-quality investigations involving the environmental effects of historical mining. This work has included research on acid mine drainage at the Iron Mountain Superfund site, including documentation of negative-pH water and associated sulfate minerals. Since 1999, he has been lead scientist for several multi-disciplinary studies regarding mercury contamination, transport, and bioaccumulation associated with historical gold mining in the Sierra Nevada and Coast Ranges of California. He is also investigating arsenic bioavailability and bioaccessibility in gold-mine waste at the Empire Mine in Grass Valley, California as part of a multi-disciplinary team involving USGS and non-USGS scientists. 

The overarching theme of Dr. Alpers' research is the environmental geochemistry of metal contamination from historical mining.  A secondary theme is the use of mineral deposits and areas contaminated by mining as laboratories for process-oriented research. His career has evolved from an emphasis on acid mine drainage (late 1980s to 2000) to an emphasis on mercury (since 2000) with growing interests in wetlands and arsenic.

Active projects:

Cache Creek Settling Basin Mercury Project

Since 2009, Dr. Alpers has been Project Chief of the Cache Creek Settling Basin (CCSB) Mercury Project. The project's objectives are: (1) to measure mercury and methylmercury concentrations and compute loads for the inflow and outflows from CCSB, an area designed to trap sediment and keep it from entering the Yolo Bypass, and (2) to assess spatial and temporal trends in methylmercury formation and bioaccumulation within the CCSB as a function of land use and habitat. Sediment transported by Cache Creek is relatively high in mercury because of historical mercury mining and active hot and cold springs in the upper Cache Creek watershed. The project is funded by the California Department of Water Resources and the USGS Cooperative Water Program.

Malakoff Diggins Erosion Rates and Sediment Sources

In cooperation with tne Nevada Irrigaion District, the California Department of Water Resources, and the California Department of Parks and Recreation, Dr. Alpers is Project Chief of an effort designed to quanitfy erosion rates from the inactive hydraulic mining pit within Malakoff Diggins State Historic Park.  The research team is using sediment "fingerprinting" techniques (mineralogy and geochemsitry) to investigate sources of fine-grained sediment that exit the pit through the Hiller Tunnel, causing impairment of downstream water bodies including Humbug Creek. Terrestrial lidar and intepretation of historical photographs are being used to quantify erosion rates.

Iron Mountain Mine: Geochemical Investigations

Iron Mountain Mine is the largest mining-related Superfund (CERCLA) site in California. Dr. Alpers is the Project Chief of a USGS team that provides technical support to the U.S. Environmental Protection Agency. Since 2012, the USGS has investigated the mineralogy and biogeochemistry of iron-rich scale that forms in a pipe conveying acidic water to a lime-neutralization water treatment plant. Starting in 2016, the USGS is investigating copper transport and attenuation in lower Spring Creek, downstream of inputs from Iron Mountain and the treatment plant. Investigations are also continuing on sulfate minerals from the underground mine workings. Dr. Alpers is also collaborating with scientists from the University of California, Davis, who are investigating iron mineralogy and geochemistry at Iron Mountain as a Mars analogue, with funding from NASA.

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