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
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Hydrologic and Aquatic Ecology Studies at Clear Lake, California
Monitoring and Modeling of Nutrients and Other Water-Quality Constituents in Tributaries to Clear Lake, California
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
Geochemical data including mercury for subsamples of deep cores from the Cache Creek Settling Basin, Yolo County, California
The Geochemistry of Mercury and Other Constituents in Redox Manipulated Sediment cores from Clear Lake, Lake County, California
Shallow Sediment Geochemistry in a Mercury-Contaminated Multi-Habitat Floodplain: Cache Creek Settling Basin, Yolo County, California (version 2.0, August 2021)
Update of the Mineral Resources Data System for California including Mineral Deposit Types
Geochemical, mineralogical, and grain-size data for in-situ solid materials and suspended sediment at Malakoff Diggins State Historic Park, Nevada County, California
Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019
Field and Laboratory data of pipe scale forming in acid mine drainage pipelines at Iron Mountain and Leviathan Mines, California
Geochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16
Discovery and potential ramifications of reduced iron-bearing nanoparticles — Magnetite, wüstite, and zero-valent iron — In wildland–urban interface fire ashes
Effects of montane watershed development on vulnerability of domestic groundwater supply during drought
Formation and prevention of pipe scale from acid mine drainage at Iron Mountain and Leviathan Mines, California, USA
Quantifying erosion rates by using terrestrial laser scanning at Malakoff Diggins State Historic Park, Nevada County, California, 2014–17
Quantifying the eroded and deposited mass of mercury-contaminated sediment by using terrestrial laser scanning at the confluence of Humbug Creek and the South Yuba River, Nevada County, California, 2011–13
PFHydro: A new watershed-scale model for post-fire runoff simulation
Geochemical data for water, streambed sediment, and fish tissue from the Sierra Nevada Mercury Impairment Project, 2011–12
Geochemistry of mercury and other constituents in subsurface sediment—Analyses from 2011 and 2012 coring campaigns, Cache Creek Settling Basin, Yolo County, California
Challenges in recovering resources from acid mine drainage
Arsenic and mercury contamination related to historical goldmining in the Sierra Nevada, California
Prediction of fish and sediment mercury in streams using landscape variables and historical mining
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Hydrologic and Aquatic Ecology Studies at Clear Lake, California
The USGS California Water Science Center conducts a variety of research activities at Clear Lake, California, including surface-water monitoring and water quality and aquatic habitat studies.Monitoring and Modeling of Nutrients and Other Water-Quality Constituents in Tributaries to Clear Lake, California
Clear Lake, the largest natural lake entirely within California, has a severe problem with harmful algal blooms (HABs). HABs can be detrimental to aquatic life because when the algae dies, sinks, and decays, the lake is deprived of the dissolved oxygen that fish need to breathe. A driving factor of these conditions are the nutrient loads being carried into the lake by soil erosion and the...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. - Data
Geochemical data including mercury for subsamples of deep cores from the Cache Creek Settling Basin, Yolo County, California
Sediment cores were collected in the Cache Creek Settling Basin (CCSB), Yolo County, California, during October 2011 at 10 locations (borehole sites) and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Detailed subsampling (3-centimeter intervals) was done at tThe Geochemistry of Mercury and Other Constituents in Redox Manipulated Sediment cores from Clear Lake, Lake County, California
Clear Lake, located within the Coast Range west of California's Central Valley, is the largest natural freshwater lake contained fully within the state and geologically is considered to be the oldest lake in North America. Clear Lake is popular for recreation and provides critical habitat to a wide variety of fish and bird species. Water quality in Clear Lake is degraded by both by mercury contamiShallow Sediment Geochemistry in a Mercury-Contaminated Multi-Habitat Floodplain: Cache Creek Settling Basin, Yolo County, California (version 2.0, August 2021)
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended sediment traUpdate of the Mineral Resources Data System for California including Mineral Deposit Types
There are more than 42,000 entries in the USGS Mineral Resources Data System (MRDS) for the State of California. Previously, the field for deposit type was sparsely populated, which made it difficult to evaluate mine sites needing environmental remediation. This has been rectified by populating the deposit type field using 100 deposit types cited in previous USGS publications, and 137 provisionalGeochemical, mineralogical, and grain-size data for in-situ solid materials and suspended sediment at Malakoff Diggins State Historic Park, Nevada County, California
This dataset includes data for in-situ solid materials and suspended sediments from surface-water samples, as well as surface-water chemistry from samples collected during storm events at Malakoff Diggins State Historic Park, Nevada County, California. In-situ solid samples were collected during 2015 along six vertical transects along the cliff walls of the mine pit. Surface-water samples were colSurface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019
Clear Lake is a 180 km2 freshwater lake located in the California Coast Range, approximately 120 km northwest of Sacramento. The lake supports a wide variety of fish and bird species and is a very popular sport-fishing destination. However, fish consumption advisories associated with mercury (Hg) contamination exist for several popular recreational species. The lake is comprised of three main regiField and Laboratory data of pipe scale forming in acid mine drainage pipelines at Iron Mountain and Leviathan Mines, California
Pipelines carrying acid mine drainage at Iron Mountain and Leviathan Mines (CA, USA) develop pipe scale, a precipitate that forms inside the pipelines. The U.S. Geological Survey is studying the composition of the pipe scale and the acid mine drainage water flowing through the pipeline through field samples and laboratory experimentation. This data release provides the data from the studies of theGeochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended sediment tra - Publications
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Discovery and potential ramifications of reduced iron-bearing nanoparticles — Magnetite, wüstite, and zero-valent iron — In wildland–urban interface fire ashes
The increase in fires at the wildland–urban interface has raised concerns about the potential environmental impact of ash remaining after burning. Here, we examined the concentrations and speciation of iron-bearing nanoparticles in wildland–urban interface ash. Total iron concentrations in ash varied between 4 and 66 mg g−1. Synchrotron X-ray absorption near-edge structure (XANES) spectroscopy ofEffects of montane watershed development on vulnerability of domestic groundwater supply during drought
Climate change is expected to reduce recharge to montane aquifers in the western United States, but it is unclear how this will impact groundwater resources in watersheds where intensive surface-water development has disrupted the natural hydrologic regime. To better understand sources of recharge and associated vulnerabilities of groundwater supply in this setting, we made a detailed geochemicalFormation and prevention of pipe scale from acid mine drainage at Iron Mountain and Leviathan Mines, California, USA
Pipelines carrying acid mine drainage (AMD) to treatment plants commonly form pipe scale, an Fe(III)-rich precipitate that forms inside the pipelines and requires periodic and costly cleanout and maintenance. Pipelines at Iron Mountain Mine (IMM) and Leviathan Mine (LM) in California carry acidic water from mine sources to a treatment plant and have developed pipe scale. Samples of scale and AMDQuantifying erosion rates by using terrestrial laser scanning at Malakoff Diggins State Historic Park, Nevada County, California, 2014–17
The abandoned hydraulic mine pit at Malakoff Diggins near Grass Valley, California, can produce large volumes of eroded sediment transportable by storm runoff. Sediment-laden water discharged from the pit is a major source of heavy metals to Humbug Creek and the South Yuba River. To develop a comprehensive sediment budget for the Malakoff Diggins mine pit and identify sources of sediment and metalQuantifying the eroded and deposited mass of mercury-contaminated sediment by using terrestrial laser scanning at the confluence of Humbug Creek and the South Yuba River, Nevada County, California, 2011–13
High-resolution, terrestrial laser scanning, also known as ground-based lidar (light detection and ranging), was used to quantify the volume of mercury-contaminated sediment eroded from an outcrop of historical placer-mining debris at the confluence of Humbug Creek and the South Yuba River in the Sierra Nevada foothills, about 17 kilometers northeast of Grass Valley, California, and delivered to aPFHydro: A new watershed-scale model for post-fire runoff simulation
Runoff increases after wildfires that burn vegetation and create a condition of soil-water repellence (SWR). A new post-fire watershed hydrological model, PFHydro, was created to explicitly simulate vegetation interception and SWR effects for four burn severity categories: high, medium, low severity and unburned. The model was applied to simulate post-fire runoff from the Upper Cache Creek WatershGeochemical data for water, streambed sediment, and fish tissue from the Sierra Nevada Mercury Impairment Project, 2011–12
This report presents geochemical data for surface water, streambed sediment, and fish tissue samples collected during low-flow conditions in 20 to 24 Sierra Nevada streams during 2011 and 2012. The dataset is part of a larger study designed to assess the factors that control mercury concentrations in fish tissue and to develop a model that predicts mercury concentration in the tissue of selected fGeochemistry of mercury and other constituents in subsurface sediment—Analyses from 2011 and 2012 coring campaigns, Cache Creek Settling Basin, Yolo County, California
Cache Creek Settling Basin was constructed in 1937 to trap sediment from Cache Creek before delivery to the Yolo Bypass, a flood conveyance for the Sacramento River system that is tributary to the Sacramento–San Joaquin Delta. Sediment management options being considered by stakeholders in the Cache Creek Settling Basin include sediment excavation; however, that could expose sediments containing eChallenges in recovering resources from acid mine drainage
Metal recovery from mine waters and effluents is not a new approach but one that has occurred largely opportunistically over the last four millennia. Due to the need for low-cost resources and increasingly stringent environmental conditions, mine waters are being considered in a fresh light with a designed, deliberate approach to resource recovery often as part of a larger water treatment evaluatiArsenic and mercury contamination related to historical goldmining in the Sierra Nevada, California
Arsenic (As) is a naturally occurring constituent in low-sulphide gold-quartz vein deposits, the dominant deposit type for lode mines in the Sierra Nevada Foothills (SNFH) gold (Au) province of California. Concentrations of naturally occurring mercury (Hg) in the SNFH Au province are low, but extensive use and loss of elemental Hg during amalgamation processing of ore from lode and placer Au deposPrediction of fish and sediment mercury in streams using landscape variables and historical mining
Widespread mercury (Hg) contamination of aquatic systems in the Sierra Nevada of California, U.S., is associated with historical use to enhance gold (Au) recovery by amalgamation. In areas affected by historical Au mining operations, including the western slope of the Sierra Nevada and downstream areas in northern California, such as San Francisco Bay and the Sacramento River–San Joaquin River Del - News