Angela Hansen - California Water Science Center
My research focuses on source and cycling of organic carbon in aquatic environments. Much of my current work involves the investigation of organic matter optical properties–as measured by absorbance and fluorescence–to demonstrate the utility of these measurements as proxies for organic compounds (i.e. DBPs, oil/gas, wastewater, Hg, etc.). I also supervise our group’s Organic Matter Research Laboratory.
Science and Products
Biogeochemistry Group
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Monitoring Cyanotoxins in California's Sacramento-San Joaquin Delta: Fixed Stations and High-Resolution Mapping Surveys
California’s Sacramento-San Joaquin River Delta (Delta) provides drinking water to about 30 million people and irrigation water to the agriculturally rich Central Valley. The Delta is also home to numerous threatened and endangered native species. The health of the Delta's aquatic ecosystems, and fish in particular, have long been in a state of decline. This is associated with decreasing...
Table of Analysis Methods
The OMRL provides a variety of laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy along with standard measurement of total dissolved organic carbon and nitrogen concentration (DOC and TDN, respectively).
Laboratory DQOs
The OMRL monitors laboratory performance though the use of QC data. Our laboratory QC data is reviewed daily and compiled in a manner that allows reviewers to compare the QC results to the Data Quality Objectives (DQOs) listed here.
Geochemical data for water, sediment, and biota in Lake Combie, California, 2017-2021
This dataset includes field measurements and laboratory analyses of surface water, bottom water (sediment-water interface), surficial (0-2 cm) sediment, pore water (0-2 cm), and biota collected in Lake Combie, California, from September 2017 through August 2021. The study area includes six sites within the reservoir where discrete samples of surface water, bottom water, sediment, and pore water we
Characterization of water residence time, nutrients, phytoplankton and related water quality constituents in the Cache Slough Complex of the California Sacramento-San Joaquin Delta in 2017 and 2018
Data was collected in the Cache Slough Complex located in the northern San Francisco Estuary to characterize water quality parameters at high spatial resolution. Data collection was conducted on three separate occasions: October 2017, May 2018, and October 2018. Data set includes nitrate, ammonium, ortho-phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, c
Optical signals of water for prediction of wastewater contamination, human-associated bacteria, and fecal indicator bacteria in surface water of Great Lake tributaries from 2011 to 2016
Data are from water samples collected from tributaries of the Great Lakes at three different drainage basin scales, including 1). watershed scale: 8 tributaries of the Great Lakes, 2). subwatershed scale: 5 locations from the greater Milwaukee, Wisconsin area, and 3). small scale: 213 storm sewers and open channel locations in three subwatersheds within the Great Lakes Basin including the Middle B
Spatial assessment of nutrients and water-quality constituents in Suisun Marsh with the salinity control gate reoperation experiment; a Delta Smelt Resiliency Strategy experiment 2018
This data release documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in Suisun Marsh and Suisun Bay in the San Francisco Estuary of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, chlorophyll, blue-green algal pigments, and
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 of field
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
Sources and characteristics of dissolved organic carbon in the McKenzie River, Oregon, related to the formation of disinfection by-products in treated drinking water
Executive SummaryThis study characterized the concentration and quality of dissolved organic carbon (DOC) in the McKenzie River, a relatively undeveloped watershed in western Oregon, and its link to forming disinfection by-products (DBPs) in treated drinking water. The study aimed to identify the primary source(s) of DOC in source water for the Eugene Water & Electric Board’s (EWEB) conventional t
Authors
Kurt D. Carpenter, Tamara E. C. Kraus, Angela M. Hansen, Bryan D. Downing, Jami H. Goldman, Jonathan Haynes, David Donahue, Karl Morgenstern
Optical properties of water for prediction of wastewater contamination, human-associated bacteria, and fecal indicator bacteria in surface water at three watershed scales
Relations between spectral absorbance and fluorescence properties of water and human-associated and fecal indicator bacteria were developed for facilitating field sensor applications to estimate wastewater contamination in waterways. Leaking wastewater conveyance infrastructure commonly contaminates receiving waters. Methods to quantify such contamination can be time consuming, expensive, and ofte
Authors
Steven R. Corsi, Laura A. DeCicco, Angela Hansen, Peter L. Lenaker, Brian A. Bergamaschi, Brian A. Pellerin, Debra Dila, Melinda Bootsma, Susan Spencer, Mark A. Borchardt, Sandra L. McLellan
An initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16
A study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission and Montclair State University, was designed to compare pesticide concentrations and the presence and prevalence of amphibian pathogens between natural ponds and two types of created wetlands, excavated ponds and stormwater basins, throughout the New Jersey Pinelands. The study described herein
Authors
Kelly L. Smalling, John F. Bunnell, Jonathan Cohl, Kristin M. Romanok, Lisa Hazard, Kirsten Monsen, Denise M. Akob, Angela M. Hansen, Michelle L. Hladik, Nicole Abdallah, Quratulain Ahmed, Araba Assan, Matthew De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna Williams
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, filter por
Authors
Angela M. Hansen, Jacob Fleck, Tamara E. C. Kraus, Bryan D. Downing, Travis von Dessonneck, Brian A. Bergamaschi
Wetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Constructed wetlands are used worldwide to improve water quality while also providing critical wetland habitat. However, wetlands have the potential to negatively impact drinking water quality by exporting dissolved organic carbon (DOC) that upon disinfection can form disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs). We used a replicated field-scale study loca
Authors
Angela M. Hansen, Tamara E. C. Kraus, Sandra M. Bachand, William R. Horwath, Philip A.M. Bachand
Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation
Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in comm
Authors
Angela Hansen, Tamara E. C. Kraus, Brian Pellerin, Jacob Fleck, Bryan D. Downing, Brian A. Bergamaschi
Mercury, monomethyl mercury, and dissolved organic carbon concentrations in surface water entering and exiting constructed wetlands treated with metal-based coagulants, Twitchell Island, California
Coagulation with metal-based salts is a practice commonly employed by drinking-water utilities to decrease particle and dissolved organic carbon concentrations in water. In addition to decreasing dissolved organic carbon concentrations, the effectiveness of iron- and aluminum-based coagulants for decreasing dissolved concentrations both of inorganic and monomethyl mercury in water was demonstrated
Authors
Elizabeth B. Stumpner, Tamara E.C. Kraus, Jacob A. Fleck, Angela M. Hansen, Sandra M. Bachand, William R. Horwath, John F. DeWild, David P. Krabbenhoft, Philip A.M. Bachand
Science and Products
- Science
Biogeochemistry Group
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.Monitoring Cyanotoxins in California's Sacramento-San Joaquin Delta: Fixed Stations and High-Resolution Mapping Surveys
California’s Sacramento-San Joaquin River Delta (Delta) provides drinking water to about 30 million people and irrigation water to the agriculturally rich Central Valley. The Delta is also home to numerous threatened and endangered native species. The health of the Delta's aquatic ecosystems, and fish in particular, have long been in a state of decline. This is associated with decreasing...Table of Analysis Methods
The OMRL provides a variety of laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy along with standard measurement of total dissolved organic carbon and nitrogen concentration (DOC and TDN, respectively).Laboratory DQOs
The OMRL monitors laboratory performance though the use of QC data. Our laboratory QC data is reviewed daily and compiled in a manner that allows reviewers to compare the QC results to the Data Quality Objectives (DQOs) listed here. - Data
Geochemical data for water, sediment, and biota in Lake Combie, California, 2017-2021
This dataset includes field measurements and laboratory analyses of surface water, bottom water (sediment-water interface), surficial (0-2 cm) sediment, pore water (0-2 cm), and biota collected in Lake Combie, California, from September 2017 through August 2021. The study area includes six sites within the reservoir where discrete samples of surface water, bottom water, sediment, and pore water weCharacterization of water residence time, nutrients, phytoplankton and related water quality constituents in the Cache Slough Complex of the California Sacramento-San Joaquin Delta in 2017 and 2018
Data was collected in the Cache Slough Complex located in the northern San Francisco Estuary to characterize water quality parameters at high spatial resolution. Data collection was conducted on three separate occasions: October 2017, May 2018, and October 2018. Data set includes nitrate, ammonium, ortho-phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, cOptical signals of water for prediction of wastewater contamination, human-associated bacteria, and fecal indicator bacteria in surface water of Great Lake tributaries from 2011 to 2016
Data are from water samples collected from tributaries of the Great Lakes at three different drainage basin scales, including 1). watershed scale: 8 tributaries of the Great Lakes, 2). subwatershed scale: 5 locations from the greater Milwaukee, Wisconsin area, and 3). small scale: 213 storm sewers and open channel locations in three subwatersheds within the Great Lakes Basin including the Middle BSpatial assessment of nutrients and water-quality constituents in Suisun Marsh with the salinity control gate reoperation experiment; a Delta Smelt Resiliency Strategy experiment 2018
This data release documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in Suisun Marsh and Suisun Bay in the San Francisco Estuary of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, chlorophyll, blue-green algal pigments, and - Publications
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 of fieldAuthorsAmanda 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 SaracenoSources and characteristics of dissolved organic carbon in the McKenzie River, Oregon, related to the formation of disinfection by-products in treated drinking water
Executive SummaryThis study characterized the concentration and quality of dissolved organic carbon (DOC) in the McKenzie River, a relatively undeveloped watershed in western Oregon, and its link to forming disinfection by-products (DBPs) in treated drinking water. The study aimed to identify the primary source(s) of DOC in source water for the Eugene Water & Electric Board’s (EWEB) conventional tAuthorsKurt D. Carpenter, Tamara E. C. Kraus, Angela M. Hansen, Bryan D. Downing, Jami H. Goldman, Jonathan Haynes, David Donahue, Karl MorgensternOptical properties of water for prediction of wastewater contamination, human-associated bacteria, and fecal indicator bacteria in surface water at three watershed scales
Relations between spectral absorbance and fluorescence properties of water and human-associated and fecal indicator bacteria were developed for facilitating field sensor applications to estimate wastewater contamination in waterways. Leaking wastewater conveyance infrastructure commonly contaminates receiving waters. Methods to quantify such contamination can be time consuming, expensive, and ofteAuthorsSteven R. Corsi, Laura A. DeCicco, Angela Hansen, Peter L. Lenaker, Brian A. Bergamaschi, Brian A. Pellerin, Debra Dila, Melinda Bootsma, Susan Spencer, Mark A. Borchardt, Sandra L. McLellanAn initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16
A study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission and Montclair State University, was designed to compare pesticide concentrations and the presence and prevalence of amphibian pathogens between natural ponds and two types of created wetlands, excavated ponds and stormwater basins, throughout the New Jersey Pinelands. The study described hereinAuthorsKelly L. Smalling, John F. Bunnell, Jonathan Cohl, Kristin M. Romanok, Lisa Hazard, Kirsten Monsen, Denise M. Akob, Angela M. Hansen, Michelle L. Hladik, Nicole Abdallah, Quratulain Ahmed, Araba Assan, Matthew De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna WilliamsProcedures 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, filter porAuthorsAngela M. Hansen, Jacob Fleck, Tamara E. C. Kraus, Bryan D. Downing, Travis von Dessonneck, Brian A. BergamaschiWetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Constructed wetlands are used worldwide to improve water quality while also providing critical wetland habitat. However, wetlands have the potential to negatively impact drinking water quality by exporting dissolved organic carbon (DOC) that upon disinfection can form disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs). We used a replicated field-scale study locaAuthorsAngela M. Hansen, Tamara E. C. Kraus, Sandra M. Bachand, William R. Horwath, Philip A.M. BachandOptical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation
Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in commAuthorsAngela Hansen, Tamara E. C. Kraus, Brian Pellerin, Jacob Fleck, Bryan D. Downing, Brian A. BergamaschiMercury, monomethyl mercury, and dissolved organic carbon concentrations in surface water entering and exiting constructed wetlands treated with metal-based coagulants, Twitchell Island, California
Coagulation with metal-based salts is a practice commonly employed by drinking-water utilities to decrease particle and dissolved organic carbon concentrations in water. In addition to decreasing dissolved organic carbon concentrations, the effectiveness of iron- and aluminum-based coagulants for decreasing dissolved concentrations both of inorganic and monomethyl mercury in water was demonstratedAuthorsElizabeth B. Stumpner, Tamara E.C. Kraus, Jacob A. Fleck, Angela M. Hansen, Sandra M. Bachand, William R. Horwath, John F. DeWild, David P. Krabbenhoft, Philip A.M. Bachand - News