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
Science and Products
Scotts Creek Nutrient Erosion Study, Lake County, California
Effects of Wildfire and Fire Retardants on Nutrient Transport in California Watersheds
Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California
Examining Erosion at Malakoff Diggins State Historic Park, a Sierra Nevada Gold Mine
Developing Spatial Data on Mineral Deposits Found on Abandoned Mine Lands
Add-on to: Determination of Mercury Loads for Cache Creek Settling Basin Inflow and Outflows and Related Investigations
Quantification of Mercury Flux in Eroding Mining Debris, Yuba River Watershed, California
Technical Support to the U.S. EPA for Leviathan Mine, Alpine County, California
Additional characterization of the impact of suction dredging, South Yuba River – Humbug Creek
Determination of Mercury Loads for Cache Creek Settling Basin Inflow and Outflows and Related Investigations
Mercury
Mercury Methylation and Bioaccumulation in the Bear River Watershed
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Scotts Creek Nutrient Erosion Study, Lake County, California
Clear Lake, the largest natural lake entirely within California, has a severe problem with harmful algal blooms which can be detrimental to aquatic life by depriving it of oxygen when the algae dies, sinks, and decays. A driving factor of these conditions are the nutrient loads being carried into the lake by soil erosion and the transport of sediment from the lake’s tributaries. Recently, an...Effects of Wildfire and Fire Retardants on Nutrient Transport in California Watersheds
Large wildfires have increased in size and frequency in the western United States over the past several decades. This has led to increased soil erosion and the transport of sediment containing nutrients into streams and reservoirs. Excess nutrients typically lead to the increased production of algae which can then lead to low levels of dissolved oxygen. This degrades the habitat for fish and...Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California
The abandoned Sulphur Bank Mercury Mine on the shores of Clear Lake in Northern California has been designated as a "Superfund Site" by the U.S. Environmental Protection Agency (EPA). This means that the EPA has determined that the area is contaminated by hazardous waste and requires cleanup because it poses a risk to human health and/or the environment. One of the chief contaminants at the site...Examining Erosion at Malakoff Diggins State Historic Park, a Sierra Nevada Gold Mine
Located in Nevada County, California, Malakoff Diggins State Historic Park was the Sierra Nevada’s largest hydraulic gold mine, operating from 1866 to 1884. Historically, part of the process of hydraulic mining included using mercury to extract gold from produced sediment through the process of amalgamation. This process left thousands of pounds of mercury and other heavy metals in the area...Developing Spatial Data on Mineral Deposits Found on Abandoned Mine Lands
Better understanding of mineral deposits and their impact on the environment, including the water system, is necessary for the protection of public health. The USGS is working with other federal and state agencies to identify the environmental behavior of these deposits and their waste products. USGS scientists are using geospatial data (data that can be mapped) to prioritize abandoned mine land...Add-on to: Determination of Mercury Loads for Cache Creek Settling Basin Inflow and Outflows and Related Investigations
The California Department of Water Resources (DWR) is responsible for the operation and maintenance of the Cache Creek Settling Basin (CCSB) in Yolo County.Quantification of Mercury Flux in Eroding Mining Debris, Yuba River Watershed, California
At two priority locations on BLM-administered land in the Yuba River watershed, the USGS has documented relatively rapid erosion of river bank material that consists of mercury (Hg)-laden sediment with a significant component of mining debris.Technical Support to the U.S. EPA for Leviathan Mine, Alpine County, California
The Leviathan Mine, located in Alpine County is one of the worst sites in California for acid mine drainage. The site is on the National Priority List for CERCLA (Superfund) (U.S. EPA, 2011) and U.S. EPA is working with ARCO/BP (the Responsible Party) on designing and implementing site remediation. The USGS did research there during the 1980s on geochemistry (e.g., Nordstrom and Ball, 1986). The...Additional characterization of the impact of suction dredging, South Yuba River – Humbug Creek
The potential impacts of suction dredging on water quality remain largely undetermined, especially with regard to trace metals including Hg. Several State of California regulatory agencies have expressed concerns that suction dredging may cause deleterious impacts with regard to turbidity and Hg contamination in downstream areas.Determination of Mercury Loads for Cache Creek Settling Basin Inflow and Outflows and Related Investigations
Mercury (Hg), a legacy pollutant from mining of mercury deposits in the Coast Ranges as well as gold deposits in the Sierra Nevada, has contaminated surface waters throughout northern California. Methylmercury (MeHg) is an organic form of Hg that bioaccumulates in food webs to elevated concentrations that threaten ecological health and human health through consumption of sport fish.Mercury
Mercury is a rare, dense metal, slightly more common than gold in the earth's crust. Mercury occurs in several different forms, the most important of which is methylmercury. Methylmercury is the form most readily incorporated into biological tissues and most toxic to humans. Methylmercury accumulates and biomagnifies in the food chain, reaching highest concentrations in predatory fish such as bass...Mercury Methylation and Bioaccumulation in the Bear River Watershed
Extensive mercury use during historical gold processing has resulted in widespread mercury contamination and bioaccumulation of methylmercury in watersheds in the northwestern Sierra Nevada (Slotton and others 1997; Alpers and Hunerlach, 2000). A recent USGS report (May and others, 2000) documented the presence of elevated mercury in fish tissues in five reservoirs in the Bear River, Deer Creek... - Data
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