Skip to main content
U.S. flag

An official website of the United States government

Emily E Woodward

(She/her)

Emily Woodward is a Research Physical Scientist with the Pennsylvania Water Science Center. Her research focuses on the fate and transport of organic contaminants in surface water and soil. 

Current Projects

  • PFAS enrichment in surface water foams
  • PFAS monitoring and source attribution in surface water
  • Co-transport of PFAS and pesticides in agricultural watersheds

 

Professional Experience

  • 2024-Present – Research Physical Scientist, Pennsylvania Water Science Center

  • 2021-2024 – Physical Scientist, Pennsylvania Water Science Center

  • 2019-2021 – Physical Scientist, California Water Science Center

  • 2018-2019 – Project Scientist, University of California, Davis

  • 2017-2018 – Lecturer, Geology Department, California State University, Sacramento

  • 2016-2018 – Postdoctoral Soil Scientist, California Water Science Center

     

Education and Certifications

  • Ph.D., Soil Science and Biogeochemistry, Pennsylvania State University, 2016

  • M.S., Soil Science, Pennsylvania State University, 2012

  • B.A., Geology and Environmental Science, University of Akron, 2010

     

Science and Products

link
Iowa stream

Costs and Benefits of Nitrapyrin

In December 2020, our research group (as part of the Food Integrated Science Team) published a review of nitrapyrin costs and benefits in the journal Environmental Science & Technology .
By
Columbia Environmental Research Center
link

Costs and Benefits of Nitrapyrin

In December 2020, our research group (as part of the Food Integrated Science Team) published a review of nitrapyrin costs and benefits in the journal Environmental Science & Technology .
Learn More
link
A yellow crop duster lets fall a cloud of spray on a cotton crop

Pesticide Fate Research Group (PFRG)

Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
By
California Water Science Center, Organic Chemistry Research Laboratory
link

Pesticide Fate Research Group (PFRG)

Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Learn More
link
View of Old Mans Creek near Iowa City, Iowa

New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams

First-ever reconnaissance study documents the off-field transport of nitrapyrin — a nitrification inhibitor applied with fertilizers as a bactericide to kill natural soil bacteria for the purpose of increasing crop yields — to adjacent streams. This study is the first step in understanding the transport, occurrence, and potential effects of nitrapyrin or similar compounds on nitrogen processing in...
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology
link

New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams

First-ever reconnaissance study documents the off-field transport of nitrapyrin — a nitrification inhibitor applied with fertilizers as a bactericide to kill natural soil bacteria for the purpose of increasing crop yields — to adjacent streams. This study is the first step in understanding the transport, occurrence, and potential effects of nitrapyrin or similar compounds on nitrogen processing in...
Learn More

Optical measurements for surface water samples collected within the Neshaminy Creek basin during November 2021

Here we report optical data collected as part of a collaborative study between USGS Pennsylvania Water Science Center, Pennsylvania Department of Environmental Protection and Water Mission Area Proxies Project. The optical measurements reported here were collected to aide in the characterization of water sources and mixtures and establish proxies (surrogates) for per- and poly-fluorinated alkyl su
By
California Water Science Center

Multiresidue extraction of current-use pesticides from complex solid matrices using energized dispersive extraction with analysis by gas and liquid chromatography tandem mass spectroscopy

A multiresidue method for solids (i.e., soil, sediment, sludge) was developed and evaluated for the analysis of pesticides and pesticide degradates. Initially, a well characterized soil was used to determine the recovery of target compounds using an Energized Dispersive Guided Extraction (EDGE) system with two extraction solvents, acetonitrile and 1:1 (v/v) hexane:acetone. Extracts were cleaned us
By
California Water Science Center

Evaluation of ELISA for the Analysis of Imidacloprid in Plasma, Liver, and Fecal Matter

Neonicotinoids have become the most widely used insecticides in world with rapid growth in applications as seed coatings. Nontarget organisms are exposed to concentrated levels of pesticidal active ingredients through ingestion of treated seeds. To better understand pesticide fate, analytical methods are necessary to rapidly screen and accurately quantitate contaminants in environmental and biolog
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center

Insecticide and fungicide concentrations in irrigation runoff and soils from a lettuce field in the Salinas Valley, California, 2019 and 2020

Irrigation runoff and soil samples were collected from a lettuce field located at the USDA-ARS Spence Research farm in the Salinas Valley, California to measure neonicotinoid insecticides (clothianidin and imidacloprid) and a fungicide (azoxystrobin) applied via coated seed and drench treatments. The field trial was designed to evaluate four treatments with replication: 1) control, untreated seed,
By
California Water Science Center

Nitrapyrin, 6-CPA, and herbicide concentrations in agricultural soils, subsurface drains, and corresponding streams in the Midwestern US

Nitrapyrin is a nitrification inhibitor that is co-applied with N-fertilizer in agroecosystems. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its degradate 6-chloropicolinic acid (6-CPA), and three widely used herbicides acetochlor, atrazine, and metolachlor. Additional environmental samples were c
By
California Water Science Center

Herbicide safeners and associated stream flow for water samples collected across Iowa and Illinois (2016-2017).

Four dichloroacetamide herbicide safeners (AD-67, benoxacor, dichlormid, and furilazole) and two co-applied herbicides (acetochlor and metolachlor) were measured in water samples from 7 streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to cor
By
Ecosystems Mission Area, California Water Science Center
Photograph of two scientists in bright yellow personal protection clothing working with water sampling tools on a bridge
Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania
Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania
Photograph of two scientists in bright yellow personal protection clothing working with water sampling tools on a bridge

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

USGS scientists sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania (Natalie Schmer, USGS).

By
Pennsylvania Water Science Center
Photograph of two scientists in bright yellow personal protection clothing working with water sampling tools on a bridge

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

USGS scientists sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania (Natalie Schmer, USGS).

By
Pennsylvania Water Science Center

Using a time-of-travel sampling approach to quantify per- and polyfluoroalkyl substances (PFAS) stream loading and source inputs in a mixed-source, urban catchment

Understanding per- and polyfluoroalkyl substances (PFAS) mass distribution in surface and groundwater systems can support source prioritization, load reduction, and water management. Thirteen sites within an urban catchment were sampled utilizing a time-of-travel sampling approach to minimize the influence of subdaily fluctuations in mass from PFAS point sources and to quantify PFAS and ancillary
Authors
Emily Woodward, Lisa A. Senior, Jacob Fleck, Larry B. Barber, Angela Hansen, Joseph W. Duris
By
Water Resources Mission Area, California Water Science Center, Pennsylvania Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Per- and polyfluorinated alkyl substances (PFAS) in Pennsylvania surface waters: A statewide assessment, associated sources, and land-use relations

The objectives of this study are to identify per- and polyfluoroalkyl substances (PFAS) in Pennsylvania surface waters, corresponding associations with potential sources of PFAS contamination (PSOC) and other parameters, and compare raw surface water concentrations to human and ecological benchmarks. Surface water samples from 161 streams were collected in September 2019 and were analyzed for 33 t
Authors
Sara E. Breitmeyer, Amy Williams, Joseph W. Duris, Lee W. Eicholtz, Dustin R. Shull, Timothy A. Wertz, Emily Woodward
By
Water Resources Mission Area, California Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, Pennsylvania Water Science Center

Multiresidue extraction of current-use pesticides from complex solid matrices using energized dispersive guided extraction with analysis by gas and liquid chromatography tandem mass spectroscopy

The development of sample processing techniques that recover a broad suite of pesticides from solid matrices, while mitigating coextracted matrix interferences, and reducing processing time is beneficial for high throughput analyses. The objective of this study was to evaluate the effectiveness of an automated extraction system for pesticide analyses in solid environmental samples. An Energized Di
Authors
Gabrielle Pecora Black, Emily Woodward, Corey Sanders, Michael S. Gross, Michelle Hladik
By
Water Resources Mission Area, California Water Science Center

Comparing imidacloprid, clothianidin, and azoxystrobin runoff from lettuce fields using a soil drench or treated seeds in the Salinas Valley, California

Neonicotinoid insecticide use has increased over the last decade, including as agricultural seed treatments (application of chemical in a coating to the seed prior to planting). In California, multiple crops, including lettuce, can be grown using neonicotinoid treated seeds or receive a direct neonicotinoid soil application (drenching) at planting. Using research plots, this study compared pestici
Authors
Emily Woodward, Michelle Hladik, Anson Main, Michael Cahn, James Orlando, Jennifer Teerlink
By
Water Resources Mission Area, California Water Science Center

Evaluation of ELISA for the analysis of imidacloprid in biological matrices: Cross-reactivities, matrix interferences, and comparison to LC-MS/MS

Imidacloprid is among the most used pesticides worldwide and there are toxicity concerns for nontarget organisms. Accurate and sensitive methods are necessary to quantitate imidacloprid concentrations in biological matrices to better understand their fate and effects. Here we evaluated an enzyme-linked immunosorbent assay (ELISA) kit for the analysis of imidacloprid in biological samples. Followin
Authors
Michael S. Gross, Emily Woodward, Michelle Hladik
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center

Widespread use of the nitrification inhibitor nitrapyrin: Assessing benefits and costs to agriculture, ecosystems, and environmental health

Agricultural production and associated applications of nitrogen (N) fertilizers have increased dramatically in the last century, and current projections to 2050 show that demands will continue to increase as the human population grows. Applied in both organic and inorganic fertilizer forms, N is an essential nutrient in crop productivity. Increased fertilizer applications, however, create the pote
Authors
Emily Woodward, Thea M. Edwards, Carrie E Givens, Dana W. Kolpin, Michelle Hladik
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Pennsylvania Water Science Center

Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program

The Delta Regional Monitoring Program was developed by the Central Valley Regional Water Quality Control Board in response to the decline of pelagic fish species in the Sacramento–San Joaquin Delta that was observed in the early 2000s. The U.S. Geological Survey, in cooperation with the Delta Regional Monitoring Program, has been responsible for collecting and analyzing surface-water samples for a
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
By
Water Resources Mission Area, California Water Science Center

Fate and transport of nitrapyrin in agroecosystems: Occurrence in agricultural soils, subsurface drains, and receiving streams in the Midwestern US

Nitrapyrin is a nitrification inhibitor that is co-applied with nitrogen fertilizer in agroecosystems. There is limited information on the fate of nitrapyrin after it is applied to agricultural soils. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its metabolite 6‑chloropicolinic acid (6‑CPA), and t
Authors
Emily Woodward, Dana W. Kolpin, Wei Zheng, Nancy L Holm, Shannon M. Meppelink, Paul J. Terrio, Michelle Hladik
By
Water Resources Mission Area, California Water Science Center

Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams
Authors
Emily Woodward, Michelle L. Hladik, Dana W. Kolpin
By
Water Resources Mission Area, California Water Science Center

Nitrapyrin in streams: The first study documenting off-field transport of a nitrogen stabilizer compound

Nitrapyrin is a bactericide that is co-applied with fertilizer to prevent nitrification and enhance corn yields. While there have been studies of the environmental fate of nitrapyrin, there is no documentation of its off-field transport to streams. In 2016, 59 water samples from 11 streams across Iowa were analyzed for nitrapyrin and its degradate, 6-chloropicolinic acid (6-CPA), along with three
Authors
Emily Woodward, Michelle Hladik, Dana W. Kolpin
By
Water Resources Mission Area, Ecosystems Mission Area, Toxic Substances Hydrology, Environmental Health Program, California Water Science Center

Non-USGS Publications**

Woodward, E., Raij-Hoffman, I., Scow, K., and Tautges, N., 2022, Alfalfa reduces winter nitrate leaching relative to organic and conventional annual vegetable systems: Resin bag field measurements and modeling with HYDRUS-1D. Journal of Soil and Water Conservation. 77 (5): 450-465.
Franklin, A.M., Williams, C.F., Andrews, D.M., Woodward, E.E., and Watson, J.E. 2016. Uptake of three antibiotics and an antiepileptic drug by wheat crops spray irrigated with wastewater treatment plant effluent. J. Environ. Qual. 45 (2) 546-554.
Woodward, E.E., Andrews, D.M., Williams, C.F., and Watson, J.E. 2014. Vadose zone transport of natural and synthetic estrogen hormones at Penn State's "Living Filter" wastewater irrigation site. J. Environ. Qual. 43 (6) 1933-1941.
Woodward, E.E., and Sasowsky, I.D. 2009. A spreadsheet program (ScallopEx) to calculate paleovelocities from cave wall scallops. Acta Carsologica 38 (2-3).

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Monitoring for Pesticides in Pennsylvania's Groundwater

This geonarrative explains and explores the results of more than 20 years of sampling. Methods for sampling and pesticide use in Pennsylvania are also described. 

By
Pennsylvania Water Science Center
USGS Releases Geonarrative Documenting Results of Pesticide Sampling in Pennsylvania Groundwater

USGS Releases Geonarrative Documenting Results of Pesticide Sampling in Pennsylvania Groundwater

USGS, in cooperation with the Pennsylvania Department of Agriculture (PDA), has released a geonarrative detailing the sampling of pesticides in...

Read Article
Science Outreach at Riverview High School

Science Outreach at Riverview High School

USGS staff participated in science outreach at Riverview High School, where students learned about environmental science and took part in interactive...

Read Article

Science and Products

link
Iowa stream

Costs and Benefits of Nitrapyrin

In December 2020, our research group (as part of the Food Integrated Science Team) published a review of nitrapyrin costs and benefits in the journal Environmental Science & Technology .
By
Columbia Environmental Research Center
link

Costs and Benefits of Nitrapyrin

In December 2020, our research group (as part of the Food Integrated Science Team) published a review of nitrapyrin costs and benefits in the journal Environmental Science & Technology .
Learn More
link
A yellow crop duster lets fall a cloud of spray on a cotton crop

Pesticide Fate Research Group (PFRG)

Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
By
California Water Science Center, Organic Chemistry Research Laboratory
link

Pesticide Fate Research Group (PFRG)

Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...
Learn More
link
View of Old Mans Creek near Iowa City, Iowa

New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams

First-ever reconnaissance study documents the off-field transport of nitrapyrin — a nitrification inhibitor applied with fertilizers as a bactericide to kill natural soil bacteria for the purpose of increasing crop yields — to adjacent streams. This study is the first step in understanding the transport, occurrence, and potential effects of nitrapyrin or similar compounds on nitrogen processing in...
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology
link

New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams

First-ever reconnaissance study documents the off-field transport of nitrapyrin — a nitrification inhibitor applied with fertilizers as a bactericide to kill natural soil bacteria for the purpose of increasing crop yields — to adjacent streams. This study is the first step in understanding the transport, occurrence, and potential effects of nitrapyrin or similar compounds on nitrogen processing in...
Learn More

Optical measurements for surface water samples collected within the Neshaminy Creek basin during November 2021

Here we report optical data collected as part of a collaborative study between USGS Pennsylvania Water Science Center, Pennsylvania Department of Environmental Protection and Water Mission Area Proxies Project. The optical measurements reported here were collected to aide in the characterization of water sources and mixtures and establish proxies (surrogates) for per- and poly-fluorinated alkyl su
By
California Water Science Center

Multiresidue extraction of current-use pesticides from complex solid matrices using energized dispersive extraction with analysis by gas and liquid chromatography tandem mass spectroscopy

A multiresidue method for solids (i.e., soil, sediment, sludge) was developed and evaluated for the analysis of pesticides and pesticide degradates. Initially, a well characterized soil was used to determine the recovery of target compounds using an Energized Dispersive Guided Extraction (EDGE) system with two extraction solvents, acetonitrile and 1:1 (v/v) hexane:acetone. Extracts were cleaned us
By
California Water Science Center

Evaluation of ELISA for the Analysis of Imidacloprid in Plasma, Liver, and Fecal Matter

Neonicotinoids have become the most widely used insecticides in world with rapid growth in applications as seed coatings. Nontarget organisms are exposed to concentrated levels of pesticidal active ingredients through ingestion of treated seeds. To better understand pesticide fate, analytical methods are necessary to rapidly screen and accurately quantitate contaminants in environmental and biolog
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center

Insecticide and fungicide concentrations in irrigation runoff and soils from a lettuce field in the Salinas Valley, California, 2019 and 2020

Irrigation runoff and soil samples were collected from a lettuce field located at the USDA-ARS Spence Research farm in the Salinas Valley, California to measure neonicotinoid insecticides (clothianidin and imidacloprid) and a fungicide (azoxystrobin) applied via coated seed and drench treatments. The field trial was designed to evaluate four treatments with replication: 1) control, untreated seed,
By
California Water Science Center

Nitrapyrin, 6-CPA, and herbicide concentrations in agricultural soils, subsurface drains, and corresponding streams in the Midwestern US

Nitrapyrin is a nitrification inhibitor that is co-applied with N-fertilizer in agroecosystems. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its degradate 6-chloropicolinic acid (6-CPA), and three widely used herbicides acetochlor, atrazine, and metolachlor. Additional environmental samples were c
By
California Water Science Center

Herbicide safeners and associated stream flow for water samples collected across Iowa and Illinois (2016-2017).

Four dichloroacetamide herbicide safeners (AD-67, benoxacor, dichlormid, and furilazole) and two co-applied herbicides (acetochlor and metolachlor) were measured in water samples from 7 streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to cor
By
Ecosystems Mission Area, California Water Science Center
Photograph of two scientists in bright yellow personal protection clothing working with water sampling tools on a bridge
Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania
Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania
Photograph of two scientists in bright yellow personal protection clothing working with water sampling tools on a bridge

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

USGS scientists sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania (Natalie Schmer, USGS).

By
Pennsylvania Water Science Center
Photograph of two scientists in bright yellow personal protection clothing working with water sampling tools on a bridge

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

Sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania

USGS scientists sampling water quality from a bridge over Beaver River, near Beaver Falls, Pennsylvania (Natalie Schmer, USGS).

By
Pennsylvania Water Science Center

Using a time-of-travel sampling approach to quantify per- and polyfluoroalkyl substances (PFAS) stream loading and source inputs in a mixed-source, urban catchment

Understanding per- and polyfluoroalkyl substances (PFAS) mass distribution in surface and groundwater systems can support source prioritization, load reduction, and water management. Thirteen sites within an urban catchment were sampled utilizing a time-of-travel sampling approach to minimize the influence of subdaily fluctuations in mass from PFAS point sources and to quantify PFAS and ancillary
Authors
Emily Woodward, Lisa A. Senior, Jacob Fleck, Larry B. Barber, Angela Hansen, Joseph W. Duris
By
Water Resources Mission Area, California Water Science Center, Pennsylvania Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Per- and polyfluorinated alkyl substances (PFAS) in Pennsylvania surface waters: A statewide assessment, associated sources, and land-use relations

The objectives of this study are to identify per- and polyfluoroalkyl substances (PFAS) in Pennsylvania surface waters, corresponding associations with potential sources of PFAS contamination (PSOC) and other parameters, and compare raw surface water concentrations to human and ecological benchmarks. Surface water samples from 161 streams were collected in September 2019 and were analyzed for 33 t
Authors
Sara E. Breitmeyer, Amy Williams, Joseph W. Duris, Lee W. Eicholtz, Dustin R. Shull, Timothy A. Wertz, Emily Woodward
By
Water Resources Mission Area, California Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, Pennsylvania Water Science Center

Multiresidue extraction of current-use pesticides from complex solid matrices using energized dispersive guided extraction with analysis by gas and liquid chromatography tandem mass spectroscopy

The development of sample processing techniques that recover a broad suite of pesticides from solid matrices, while mitigating coextracted matrix interferences, and reducing processing time is beneficial for high throughput analyses. The objective of this study was to evaluate the effectiveness of an automated extraction system for pesticide analyses in solid environmental samples. An Energized Di
Authors
Gabrielle Pecora Black, Emily Woodward, Corey Sanders, Michael S. Gross, Michelle Hladik
By
Water Resources Mission Area, California Water Science Center

Comparing imidacloprid, clothianidin, and azoxystrobin runoff from lettuce fields using a soil drench or treated seeds in the Salinas Valley, California

Neonicotinoid insecticide use has increased over the last decade, including as agricultural seed treatments (application of chemical in a coating to the seed prior to planting). In California, multiple crops, including lettuce, can be grown using neonicotinoid treated seeds or receive a direct neonicotinoid soil application (drenching) at planting. Using research plots, this study compared pestici
Authors
Emily Woodward, Michelle Hladik, Anson Main, Michael Cahn, James Orlando, Jennifer Teerlink
By
Water Resources Mission Area, California Water Science Center

Evaluation of ELISA for the analysis of imidacloprid in biological matrices: Cross-reactivities, matrix interferences, and comparison to LC-MS/MS

Imidacloprid is among the most used pesticides worldwide and there are toxicity concerns for nontarget organisms. Accurate and sensitive methods are necessary to quantitate imidacloprid concentrations in biological matrices to better understand their fate and effects. Here we evaluated an enzyme-linked immunosorbent assay (ELISA) kit for the analysis of imidacloprid in biological samples. Followin
Authors
Michael S. Gross, Emily Woodward, Michelle Hladik
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center

Widespread use of the nitrification inhibitor nitrapyrin: Assessing benefits and costs to agriculture, ecosystems, and environmental health

Agricultural production and associated applications of nitrogen (N) fertilizers have increased dramatically in the last century, and current projections to 2050 show that demands will continue to increase as the human population grows. Applied in both organic and inorganic fertilizer forms, N is an essential nutrient in crop productivity. Increased fertilizer applications, however, create the pote
Authors
Emily Woodward, Thea M. Edwards, Carrie E Givens, Dana W. Kolpin, Michelle Hladik
By
Ecosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Pennsylvania Water Science Center

Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program

The Delta Regional Monitoring Program was developed by the Central Valley Regional Water Quality Control Board in response to the decline of pelagic fish species in the Sacramento–San Joaquin Delta that was observed in the early 2000s. The U.S. Geological Survey, in cooperation with the Delta Regional Monitoring Program, has been responsible for collecting and analyzing surface-water samples for a
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
By
Water Resources Mission Area, California Water Science Center

Fate and transport of nitrapyrin in agroecosystems: Occurrence in agricultural soils, subsurface drains, and receiving streams in the Midwestern US

Nitrapyrin is a nitrification inhibitor that is co-applied with nitrogen fertilizer in agroecosystems. There is limited information on the fate of nitrapyrin after it is applied to agricultural soils. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its metabolite 6‑chloropicolinic acid (6‑CPA), and t
Authors
Emily Woodward, Dana W. Kolpin, Wei Zheng, Nancy L Holm, Shannon M. Meppelink, Paul J. Terrio, Michelle Hladik
By
Water Resources Mission Area, California Water Science Center

Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams
Authors
Emily Woodward, Michelle L. Hladik, Dana W. Kolpin
By
Water Resources Mission Area, California Water Science Center

Nitrapyrin in streams: The first study documenting off-field transport of a nitrogen stabilizer compound

Nitrapyrin is a bactericide that is co-applied with fertilizer to prevent nitrification and enhance corn yields. While there have been studies of the environmental fate of nitrapyrin, there is no documentation of its off-field transport to streams. In 2016, 59 water samples from 11 streams across Iowa were analyzed for nitrapyrin and its degradate, 6-chloropicolinic acid (6-CPA), along with three
Authors
Emily Woodward, Michelle Hladik, Dana W. Kolpin
By
Water Resources Mission Area, Ecosystems Mission Area, Toxic Substances Hydrology, Environmental Health Program, California Water Science Center

Non-USGS Publications**

Woodward, E., Raij-Hoffman, I., Scow, K., and Tautges, N., 2022, Alfalfa reduces winter nitrate leaching relative to organic and conventional annual vegetable systems: Resin bag field measurements and modeling with HYDRUS-1D. Journal of Soil and Water Conservation. 77 (5): 450-465.
Franklin, A.M., Williams, C.F., Andrews, D.M., Woodward, E.E., and Watson, J.E. 2016. Uptake of three antibiotics and an antiepileptic drug by wheat crops spray irrigated with wastewater treatment plant effluent. J. Environ. Qual. 45 (2) 546-554.
Woodward, E.E., Andrews, D.M., Williams, C.F., and Watson, J.E. 2014. Vadose zone transport of natural and synthetic estrogen hormones at Penn State's "Living Filter" wastewater irrigation site. J. Environ. Qual. 43 (6) 1933-1941.
Woodward, E.E., and Sasowsky, I.D. 2009. A spreadsheet program (ScallopEx) to calculate paleovelocities from cave wall scallops. Acta Carsologica 38 (2-3).

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Monitoring for Pesticides in Pennsylvania's Groundwater

This geonarrative explains and explores the results of more than 20 years of sampling. Methods for sampling and pesticide use in Pennsylvania are also described. 

By
Pennsylvania Water Science Center
USGS Releases Geonarrative Documenting Results of Pesticide Sampling in Pennsylvania Groundwater

USGS Releases Geonarrative Documenting Results of Pesticide Sampling in Pennsylvania Groundwater

USGS, in cooperation with the Pennsylvania Department of Agriculture (PDA), has released a geonarrative detailing the sampling of pesticides in...

Read Article
Science Outreach at Riverview High School

Science Outreach at Riverview High School

USGS staff participated in science outreach at Riverview High School, where students learned about environmental science and took part in interactive...

Read Article
Was this page helpful?