Jacob A Fleck
Jacob A Fleck - California Water Science Center
Science and Products
Investigation of Linkages Between Management Practices Used in Sacramento-San Joaquin Delta Rice Production and Loads of Dissolved Organic Matter and Disinfection Byproduct Precursors
The primary objective of this study is to expand our current understanding of how to manage rice production in the Sacramento-San Joaquin Delta in a manner that minimizes loads of water quality contaminants to Delta waters.
Evaluating coagulation techniques to reduce the transport of Hg from mine-affected and active geothermal Hg-source watersheds
Our objective is to determine the effectiveness of coagulation and adsorption techniques in removing mercury from contaminated surface waters of the Cache Creek watershed.
Assessment of methyl mercury (MeHg) release from sediment formed in wetland treatment cells designed to remove mercury from surface waters using in situ coagulation
Our objective is to determine the relative propensity of sediment material formed under two different in situ coagulation treatments (iron sulfate, polyaluminum chloride) to release MeHg into surface waters under environmentally relevant conditions that may affect flocculant stability and MeHg production rates.
Monitoring Mercury and Methylmercury in Water, Sediment and Biota in Combie Reservoir Before and After Dredging and Mercury Removal
Dredging to maintain water storage capacity by the Nevada Irrigation District (NID) occurred at Lake Combie reservoir, one of several reservoirs along the Bear River, California over the past 40 years on an as-needed basis to maintain water storage capacity. Maintenance dredging operations were halted by the Central Valley Regional Water Quality Control Board (CVRWQCB) in 2002 because of elevated...
Mercury cycling, bioaccumulation, and risk across western North America: a landscape scale synthesis linking long-term datasets
Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may...
Filter Total Items: 29
Surface-Water Geochemistry of Mercury and other Constituents in Clear Lake, Lake County, California Surface-Water Geochemistry of Mercury and other Constituents in Clear Lake, Lake County, California
Clear Lake is a 180 km2 freshwater lake located approximately 120 km northwest of Sacramento in the California Coast Range. The lake is a popular sport-fishing destination, however, there are fish consumption advisories associated with mercury (Hg) contamination for several species. The lake has three arms: a large open-water region to the northwest (Upper Arm), a smaller and narrower...
Environmental Sampling and Modeling Results to Characterize Surface-Water Quality at 32 Sites Across the Potomac River Watershed, 2022 (ver. 3.0, April 2025) Environmental Sampling and Modeling Results to Characterize Surface-Water Quality at 32 Sites Across the Potomac River Watershed, 2022 (ver. 3.0, April 2025)
This data release presents chemical results from investigations of surface-water quality in the Potomac River watershed (encompassing Washington, D.C. and parts of West Virginia, Virginia, Pennsylvania, and Maryland) conducted during low-flow conditions in July through September of 2022 and modeling results that support interpretative products. Water-quality sampling: A sampling campaign...
Laboratory-based optical measurements for surface water samples collected within the Fraser River in the Upper Colorado River Basin from September 2021 through September 2023 Laboratory-based optical measurements for surface water samples collected within the Fraser River in the Upper Colorado River Basin from September 2021 through September 2023
Optical spectra reported here are collected from 17 surface water sampling sites within the Fraser River, a headwaters drainage of the Upper Colorado River Basin in the central western United States. The sample collection was conducted as part of the partnership between the United States Geological Survey’s (USGS) Next Generation Water Observation System (NGWOS) and Proxies Project, in
2022 Organic Matter Research Lab Sacramento, California Vectorized Fluorescence Data 2022 Organic Matter Research Lab Sacramento, California Vectorized Fluorescence Data
The U.S. Geological Survey (USGS) California Water Science Center (CAWSC) Organic Matter Research Laboratory (OMRL) provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy. Optical measurements such as absorbance and fluorescence are used to gain insight into...
2022 Organic Matter Research Lab Sacramento, California Full Spectra Absorbance Data 2022 Organic Matter Research Lab Sacramento, California Full Spectra Absorbance Data
The U.S. Geological Survey (USGS) California Water Science Center (CAWSC) Organic Matter Research Laboratory (OMRL) provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy. Optical measurements such as absorbance and fluorescence are used to gain insight into...
Laboratory optical measurements in support of assessing PFAS enrichment in natural foams on surface waters within the Delaware River Basin Laboratory optical measurements in support of assessing PFAS enrichment in natural foams on surface waters within the Delaware River Basin
One phenomenon that has been shown to concentrate and release per- and polyfluoroalkyl substances (PFAS) in surface water is the formation of natural foams. For surface water foams to form, surface active compounds or surfactants must be present in the water along with a source of gas bubbles. Some examples of surface-active compounds include humic and fulvic acids, colloidal particles...
Filter Total Items: 41
Field techniques for fluorescence measurements targeting dissolved organic matter, hydrocarbons, and wastewater in environmental waters: Principles and guidelines for instrument selection, operation and maintenance, quality assurance, and data reporting Field techniques for fluorescence measurements targeting dissolved organic matter, hydrocarbons, and wastewater in environmental waters: Principles and guidelines for instrument selection, operation and maintenance, quality assurance, and data reporting
The use of field deployable fluorescence sensors by the U.S. Geological Survey has become increasingly common for a wide variety of surface water and groundwater investigations. This report addresses field deployable fluorometers that measure the fluorescence response of various substances in water exposed to incident light generated by the sensor. An introduction to the basic principles...
Authors
Amanda Booth, Jacob Fleck, Brian A. Pellerin, Angela Hansen, Alexandra Etheridge, Guy M. Foster, Jennifer L. Graham, Brian A. Bergamaschi, Kurt D. Carpenter, Bryan D. Downing, Stewart A. Rounds, JohnFranco Saraceno
Wetland management strategy to reduce mercury export in water and bioaccumulation in fish Wetland management strategy to reduce mercury export in water and bioaccumulation in fish
Wetland environments provide numerous ecosystem services but also facilitate methylmercury (MeHg) production and bioaccumulation. We developed a wetland‐management technique to reduce MeHg concentrations in wetland fish and water. We physically modified seasonal wetlands by constructing open‐ and deep‐water treatment cells at the downstream end of seasonal wetlands to promote naturally...
Authors
Joshua T. Ackerman, Jacob Fleck, Collin A. Eagles-Smith, Mark C. Marvin-DiPasquale, Lisamarie Windham-Myers, Mark P. Herzog, Harry L. McQuillen
Coagulant and sorbent efficacy in removing mercury from surface waters in the Cache Creek watershed, California Coagulant and sorbent efficacy in removing mercury from surface waters in the Cache Creek watershed, California
Cache Creek drains part of northern California’s Coast Ranges and is an important source of mercury (Hg) to the Sacramento–San Joaquin Delta. Cache Creek is contaminated with Hg from several sources, including historical Hg and gold mines, native Hg in the soils, and active mineral springs. In laboratory experiments in a study conducted by the U.S. Geological Survey, in cooperation with...
Authors
Erica R. De Parsia, Jacob A. Fleck, David P. Krabbenhoft, Kim Hoang, David Roth, Paul Randall
Geochemical data for water, streambed sediment, and fish tissue from the Sierra Nevada Mercury Impairment Project, 2011–12 Geochemical 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...
Authors
Elizabeth B. Stumpner, Charles N. Alpers, Mark C. Marvin-DiPasquale, Jennifer L. Agee, Evangelos Kakouros, Michelle R. Arias, Le H. Kieu, David A. Roth, Darrell G. Slotton, Jacob A. Fleck
Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Advances in spectroscopic techniques have led to an increase in the use of optical measurements (absorbance and fluorescence) to assess dissolved organic matter composition and infer sources and processing. Although optical measurements are easy to make, they can be affected by many variables rendering them less comparable, including by inconsistencies in sample collection (for example...
Authors
Angela M. Hansen, Jacob Fleck, Tamara E. C. Kraus, Bryan D. Downing, Travis von Dessonneck, Brian A. Bergamaschi
Methylmercury dynamics in Upper Sacramento Valley rice fields with low background soil mercury levels Methylmercury dynamics in Upper Sacramento Valley rice fields with low background soil mercury levels
Few studies have considered how methylmercury (MeHg, a toxic form of Hg produced in anaerobic soils) production in rice (Oryza sativa L.) fields can affect water quality, and little is known about MeHg dynamics in rice fields. Surface water MeHg and total Hg (THg) imports, exports, and storage were studied in two commercial rice fields in the Sacramento Valley, California, where soil THg...
Authors
K. Christy Tanner, Lisamarie Windham-Myers, Mark C. Marvin-DiPasquale, Jacob Fleck, Kenneth W. Tate, Bruce A. Linquist
Science and Products
Investigation of Linkages Between Management Practices Used in Sacramento-San Joaquin Delta Rice Production and Loads of Dissolved Organic Matter and Disinfection Byproduct Precursors
The primary objective of this study is to expand our current understanding of how to manage rice production in the Sacramento-San Joaquin Delta in a manner that minimizes loads of water quality contaminants to Delta waters.
Evaluating coagulation techniques to reduce the transport of Hg from mine-affected and active geothermal Hg-source watersheds
Our objective is to determine the effectiveness of coagulation and adsorption techniques in removing mercury from contaminated surface waters of the Cache Creek watershed.
Assessment of methyl mercury (MeHg) release from sediment formed in wetland treatment cells designed to remove mercury from surface waters using in situ coagulation
Our objective is to determine the relative propensity of sediment material formed under two different in situ coagulation treatments (iron sulfate, polyaluminum chloride) to release MeHg into surface waters under environmentally relevant conditions that may affect flocculant stability and MeHg production rates.
Monitoring Mercury and Methylmercury in Water, Sediment and Biota in Combie Reservoir Before and After Dredging and Mercury Removal
Dredging to maintain water storage capacity by the Nevada Irrigation District (NID) occurred at Lake Combie reservoir, one of several reservoirs along the Bear River, California over the past 40 years on an as-needed basis to maintain water storage capacity. Maintenance dredging operations were halted by the Central Valley Regional Water Quality Control Board (CVRWQCB) in 2002 because of elevated...
Mercury cycling, bioaccumulation, and risk across western North America: a landscape scale synthesis linking long-term datasets
Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may...
Filter Total Items: 29
Surface-Water Geochemistry of Mercury and other Constituents in Clear Lake, Lake County, California Surface-Water Geochemistry of Mercury and other Constituents in Clear Lake, Lake County, California
Clear Lake is a 180 km2 freshwater lake located approximately 120 km northwest of Sacramento in the California Coast Range. The lake is a popular sport-fishing destination, however, there are fish consumption advisories associated with mercury (Hg) contamination for several species. The lake has three arms: a large open-water region to the northwest (Upper Arm), a smaller and narrower...
Environmental Sampling and Modeling Results to Characterize Surface-Water Quality at 32 Sites Across the Potomac River Watershed, 2022 (ver. 3.0, April 2025) Environmental Sampling and Modeling Results to Characterize Surface-Water Quality at 32 Sites Across the Potomac River Watershed, 2022 (ver. 3.0, April 2025)
This data release presents chemical results from investigations of surface-water quality in the Potomac River watershed (encompassing Washington, D.C. and parts of West Virginia, Virginia, Pennsylvania, and Maryland) conducted during low-flow conditions in July through September of 2022 and modeling results that support interpretative products. Water-quality sampling: A sampling campaign...
Laboratory-based optical measurements for surface water samples collected within the Fraser River in the Upper Colorado River Basin from September 2021 through September 2023 Laboratory-based optical measurements for surface water samples collected within the Fraser River in the Upper Colorado River Basin from September 2021 through September 2023
Optical spectra reported here are collected from 17 surface water sampling sites within the Fraser River, a headwaters drainage of the Upper Colorado River Basin in the central western United States. The sample collection was conducted as part of the partnership between the United States Geological Survey’s (USGS) Next Generation Water Observation System (NGWOS) and Proxies Project, in
2022 Organic Matter Research Lab Sacramento, California Vectorized Fluorescence Data 2022 Organic Matter Research Lab Sacramento, California Vectorized Fluorescence Data
The U.S. Geological Survey (USGS) California Water Science Center (CAWSC) Organic Matter Research Laboratory (OMRL) provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy. Optical measurements such as absorbance and fluorescence are used to gain insight into...
2022 Organic Matter Research Lab Sacramento, California Full Spectra Absorbance Data 2022 Organic Matter Research Lab Sacramento, California Full Spectra Absorbance Data
The U.S. Geological Survey (USGS) California Water Science Center (CAWSC) Organic Matter Research Laboratory (OMRL) provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy. Optical measurements such as absorbance and fluorescence are used to gain insight into...
Laboratory optical measurements in support of assessing PFAS enrichment in natural foams on surface waters within the Delaware River Basin Laboratory optical measurements in support of assessing PFAS enrichment in natural foams on surface waters within the Delaware River Basin
One phenomenon that has been shown to concentrate and release per- and polyfluoroalkyl substances (PFAS) in surface water is the formation of natural foams. For surface water foams to form, surface active compounds or surfactants must be present in the water along with a source of gas bubbles. Some examples of surface-active compounds include humic and fulvic acids, colloidal particles...
Filter Total Items: 41
Field techniques for fluorescence measurements targeting dissolved organic matter, hydrocarbons, and wastewater in environmental waters: Principles and guidelines for instrument selection, operation and maintenance, quality assurance, and data reporting Field techniques for fluorescence measurements targeting dissolved organic matter, hydrocarbons, and wastewater in environmental waters: Principles and guidelines for instrument selection, operation and maintenance, quality assurance, and data reporting
The use of field deployable fluorescence sensors by the U.S. Geological Survey has become increasingly common for a wide variety of surface water and groundwater investigations. This report addresses field deployable fluorometers that measure the fluorescence response of various substances in water exposed to incident light generated by the sensor. An introduction to the basic principles...
Authors
Amanda Booth, Jacob Fleck, Brian A. Pellerin, Angela Hansen, Alexandra Etheridge, Guy M. Foster, Jennifer L. Graham, Brian A. Bergamaschi, Kurt D. Carpenter, Bryan D. Downing, Stewart A. Rounds, JohnFranco Saraceno
Wetland management strategy to reduce mercury export in water and bioaccumulation in fish Wetland management strategy to reduce mercury export in water and bioaccumulation in fish
Wetland environments provide numerous ecosystem services but also facilitate methylmercury (MeHg) production and bioaccumulation. We developed a wetland‐management technique to reduce MeHg concentrations in wetland fish and water. We physically modified seasonal wetlands by constructing open‐ and deep‐water treatment cells at the downstream end of seasonal wetlands to promote naturally...
Authors
Joshua T. Ackerman, Jacob Fleck, Collin A. Eagles-Smith, Mark C. Marvin-DiPasquale, Lisamarie Windham-Myers, Mark P. Herzog, Harry L. McQuillen
Coagulant and sorbent efficacy in removing mercury from surface waters in the Cache Creek watershed, California Coagulant and sorbent efficacy in removing mercury from surface waters in the Cache Creek watershed, California
Cache Creek drains part of northern California’s Coast Ranges and is an important source of mercury (Hg) to the Sacramento–San Joaquin Delta. Cache Creek is contaminated with Hg from several sources, including historical Hg and gold mines, native Hg in the soils, and active mineral springs. In laboratory experiments in a study conducted by the U.S. Geological Survey, in cooperation with...
Authors
Erica R. De Parsia, Jacob A. Fleck, David P. Krabbenhoft, Kim Hoang, David Roth, Paul Randall
Geochemical data for water, streambed sediment, and fish tissue from the Sierra Nevada Mercury Impairment Project, 2011–12 Geochemical 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...
Authors
Elizabeth B. Stumpner, Charles N. Alpers, Mark C. Marvin-DiPasquale, Jennifer L. Agee, Evangelos Kakouros, Michelle R. Arias, Le H. Kieu, David A. Roth, Darrell G. Slotton, Jacob A. Fleck
Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Advances in spectroscopic techniques have led to an increase in the use of optical measurements (absorbance and fluorescence) to assess dissolved organic matter composition and infer sources and processing. Although optical measurements are easy to make, they can be affected by many variables rendering them less comparable, including by inconsistencies in sample collection (for example...
Authors
Angela M. Hansen, Jacob Fleck, Tamara E. C. Kraus, Bryan D. Downing, Travis von Dessonneck, Brian A. Bergamaschi
Methylmercury dynamics in Upper Sacramento Valley rice fields with low background soil mercury levels Methylmercury dynamics in Upper Sacramento Valley rice fields with low background soil mercury levels
Few studies have considered how methylmercury (MeHg, a toxic form of Hg produced in anaerobic soils) production in rice (Oryza sativa L.) fields can affect water quality, and little is known about MeHg dynamics in rice fields. Surface water MeHg and total Hg (THg) imports, exports, and storage were studied in two commercial rice fields in the Sacramento Valley, California, where soil THg...
Authors
K. Christy Tanner, Lisamarie Windham-Myers, Mark C. Marvin-DiPasquale, Jacob Fleck, Kenneth W. Tate, Bruce A. Linquist