Matthew De Parsia
Matthew De Parsia is a hydrologist at the California Water Science Center.
Science and Products
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...
Filter Total Items: 15
Concurrent Occurrence of Pesticides and Per- and Polyfluoroalkyl Substances (PFAS) in Agricultural Streams in California, USA Concurrent Occurrence of Pesticides and Per- and Polyfluoroalkyl Substances (PFAS) in Agricultural Streams in California, USA
Per-and polyfluoroalkyl substances (PFAS) are frequently found in streams, with most research focusing on urban sources of PFAS to surface water (e.g., firefighting foams, industrial releases, and wastewater treatment plant discharges). Pesticide applications are an under-investigated source of PFAS to streams in both agricultural and urban areas. There are few studies that analyze the...
Organic Contaminants at Trespass Cannabis Grows on Federal Land in California, USA Organic Contaminants at Trespass Cannabis Grows on Federal Land in California, USA
Despite the legalization of recreational cannabis in California, illegal cultivation persists, particularly on public lands (trespass grows). These operations often divert water unlawfully and apply unauthorized chemical fertilizers and pesticides. This dataset reports the presence, and in some cases concentrations, of persistent chemicals in soil, water, and sediment in nearby streams...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2024 Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2024
Zooplankton samples were collected in the summer/fall of 2024 at multiple sites in the Sacramento River, Yolo Bypass, and Cache Slough Region of California and analyzed for a suite of 160 current-use pesticides and pesticide degradates by the U.S. Geological Survey Organic Chemistry Research Laboratory. Samples were collected at two sites in the Bypass, at a comparison site on the...
Pesticide Concentrations Measured During In-Situ Active Water Sampler Testing in Solano County, California, 2023 Pesticide Concentrations Measured During In-Situ Active Water Sampler Testing in Solano County, California, 2023
A novel U.S. Geological Survey-developed active water sampler was deployed at Ulatis Creek in Solano County, California for 24 hours from November 15, 2023 to November 16, 2023. Discrete surface water samples were collected at the start and end points of the active water sampler deployment interval for comparison to the active water sampler. Samples from the active water sampler and the...
Pesticide concentrations in multiple stream matrices collected near Mead, Nebraska, 2022 Pesticide concentrations in multiple stream matrices collected near Mead, Nebraska, 2022
The AltEn bioenergy plant (Mead, Nebraska, USA) previously (2015 to 2021) generated ethanol from almost 100% unused/expired treated corn seeds. This use of treated corn seeds as a feedstock for ethanol production resulted in accumulation of large amounts of contaminated wastewater and solid residue at the plant, a portion of which was applied to surrounding farmland. To better understand...
6PPD-quinone concentrations in the Sacramento-San Joaquin Delta, California, 2018-2024 6PPD-quinone concentrations in the Sacramento-San Joaquin Delta, California, 2018-2024
The Sacramento-San Joaquin Delta is a crucial river delta that supplies a significant portion of California's freshwater for agricultural and residential use and serves as critical habitat for numerous state and federally listed species of concern. In several areas, urban stormwater drains discharge directly into the Delta. 6PPD-quinone (6PPD-Q, 2-anilo-5-[(4-methylpentan-2- yl)amino...
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...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2022 and 2023 Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2022 and 2023
Zooplankton samples were collected in the summer/fall of 2022 and 2023 at multiple sites in the Sacramento River, Yolo Bypass, and Cache Slough Region of California and analyzed for a suite of 160 current-use pesticides and pesticide degradates by the U.S. Geological Survey Organic Chemistry Research Laboratory. In 2022 samples were collected at two sites in the Bypass and at a...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2021 Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2021
Zooplankton samples were collected at one site upstream of the Yolo Bypass in Northern California, three sites within the Bypass, and at a comparison site on the Sacramento River below the city of Sacramento and analyzed for a large suite of current-use pesticides and degradates. Samples were collected every two weeks from early August 2021 to mid-October 2021. Samples were collected by...
Results from U.S. Geological Survey Environmental Health Food Resources Lifecycle Integrated Science Team, Graton Pesticides (GRAPE) Study, in Graton, California, April–May 2021 Results from U.S. Geological Survey Environmental Health Food Resources Lifecycle Integrated Science Team, Graton Pesticides (GRAPE) Study, in Graton, California, April–May 2021
In the spring of 2021, six households with private wells were selected throughout Graton, California, based on proximity to agriculture (within one mile of agriculture), well depth (i.e., less than 150 feet in depth), and well type (i.e., dug versus drilled). Silicone bands were deployed for 30 days at outdoor locations at each household to passively sample pesticides in ambient air. On...
Naled and dichlorvos in water and aquatic organisms from a canal and rice fields near Sacramento, California Naled and dichlorvos in water and aquatic organisms from a canal and rice fields near Sacramento, California
Ultra-low volumes of naled are applied by aircraft over rice fields and canals to reduce adult mosquito populations near Sacramento, California. Each summer, the pesticide is applied approximately 7-10 times between July and October. Naled and its major degradate (dichlorvos) were quantified in water, biofilm, and invertebrates following aerial applications. In 2020, samples were...
Current-use pesticides, nutrients, chloride, and metals in ponds and stormwater basins of the New Jersey Pinelands, 2018-20 Current-use pesticides, nutrients, chloride, and metals in ponds and stormwater basins of the New Jersey Pinelands, 2018-20
The data presented in this data release include concentrations of current-use pesticides, nutrients, chloride, and metals in surface water collected from 60 wetlands including natural ponds, excavated ponds (Xponds), and stormwater basins in the New Jersey Pinelands, 2018-20. Site information, basic water-quality parameters, and method information also are included.
Effects of flow on pesticides in water and zooplankton in the northern Sacramento-San Joaquin Delta Effects of flow on pesticides in water and zooplankton in the northern Sacramento-San Joaquin Delta
Zooplankton are a key food source for juvenile fishes in estuaries worldwide, including California’s Sacramento–San Joaquin Delta (hereafter Delta); both zooplankton quality and quantity are critical to ecosystem health. Zooplankton may be affected by pesticides in water and the food web, and the Delta is known to contain complex pesticide mixtures. In this study, we evaluated pesticide
Authors
James Orlando, Laura Twardochleb, David Bosworth, Michelle L. Hladik, Corey Sanders, Matt De Parsia, Brittany E. Davis
Identifying organic contaminants at trespass cannabis grows on federal land in California, USA Identifying organic contaminants at trespass cannabis grows on federal land in California, USA
Despite the legalization of recreational cannabis in California, USA, illegal cannabis cultivation remains pervasive, partly through the establishment of illegal cultivation on public lands (trespass grows). These operations often illegally divert water for irrigation and perform unauthorized applications of chemical fertilizers and pesticides. This work investigates a broad suite of...
Authors
Gabrielle Pecora Black, Matt De Parsia, Matthew Uychutin, Mourad W. Gabriel, Ivan Medel, Greta Wengert, Clayton D. Raines, Dana W. Kolpin, Laura E. Hubbard, Michelle L. Hladik
Pesticide concentrations in multiple physical and biological stream matrices are impacted by a bioenergy production facility receiving pesticide coated corn seeds Pesticide concentrations in multiple physical and biological stream matrices are impacted by a bioenergy production facility receiving pesticide coated corn seeds
Insecticide and fungicide seed coatings have become prevalent in conventional agriculture in recent decades. From 2015 to 2021, the AltEn bioenergy plant (Mead, Nebraska, USA) generated ethanol from almost 100% unused/expired treated corn seeds. This use of these seeds for ethanol production resulted in the accumulation of large amounts of contaminated wastewater and solid residue, a...
Authors
Michelle L. Hladik, Dana W. Kolpin, Matthew D. De Parsia, Daniel D. Snow, Shannon Bartelt-Hunt, Brenda Densmore, Laura E. Hubbard, David L. Rus, Jonathan J. Spurgeon, Brittany G. Perrotta, Karen A. Kidd, Johanna M. Kraus, Carrie E. Givens, Christopher James Kotalik, David Walters
6PPD-quinone in water from the San Francisco-San Joaquin Delta, California, 2018-2024 6PPD-quinone in water from the San Francisco-San Joaquin Delta, California, 2018-2024
The Sacramento-San Joaquin Delta (Delta) is an expansive river delta supplying a large portion of California’s fresh water for agriculture and residential use, and it is also an area of critical habitat for numerous state and federally listed species of concern. In many locations, urban stormwater flows directly into the Delta. 6PPD-quinone (6PPD-Q), an ozonation byproduct of a tire...
Authors
Gabrielle Pecora Black, Matthew D. De Parsia, Matthew Uychutin, Rachael F. Lane, James Orlando, Michelle L. Hladik
Pesticide concentrations of surface water and suspended sediment in Yolo By-Pass and Cache Slough Complex, California, 2019–2021 Pesticide concentrations of surface water and suspended sediment in Yolo By-Pass and Cache Slough Complex, California, 2019–2021
Managed flow pulses in the north Sacramento-San Joaquin Delta are an adaptive management tool used in efforts to enhance food availability in delta smelt (Hypomesus transpacificus) habitat as part of the North Delta Food Subsidies Action. The California Department of Water Resources (DWR) monitors non-managed seasonal and local flow pulses and managed flow pulses from agricultural...
Authors
Matthew Uychutin, James L. Orlando, Michelle L. Hladik, Corey J. Sanders, Michael S. Gross, Matthew D. De Parsia, Elisabeth M. LaBarbera, Laura Twardochleb, Brittany E. Davis
Methods of analysis—Determination of pesticides in filtered water and suspended sediment using liquid chromatography- and gas chromatography-tandem mass spectrometry Methods of analysis—Determination of pesticides in filtered water and suspended sediment using liquid chromatography- and gas chromatography-tandem mass spectrometry
The widespread application of pesticides in agricultural and urban areas leads to their presence in surface waters. Presence of these biologically active chemicals in environmental waters potentially has adverse effects on nontarget organisms. To better understand the environmental fate of these contaminants, a robust method to capture chemicals with wide-ranging physicochemical...
Authors
Michael S. Gross, Corey J. Sanders, Matthew D. De Parsia, Michelle L. Hladik
Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19 Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19
Passive sampler devices were deployed in six northern California streams five times between November 2018 and December 2019 to measure the presence or absence of current-use pesticides in surface water. In the targeted areas, there are reported pesticide uses for agriculture, commercial forestry, and rights of way maintenance along with unreported pesticide use at private residences and...
Authors
Matthew D. De Parsia, James L. Orlando, Michelle L. Hladik
Pesticide concentrations associated with augmented flow pulses in the Yolo Bypass and Cache Slough Complex, California Pesticide concentrations associated with augmented flow pulses in the Yolo Bypass and Cache Slough Complex, California
Surface-water and suspended-sediment samples were collected and analyzed by the U.S. Geological Survey for multiple current-use pesticides and pesticide degradates approximately every 2 weeks at up to five sites in the Yolo Bypass and Cache Slough Complex before, during, and after augmented flow pulses in summer and fall 2016 and 2018 as well as during ambient flow conditions in summer...
Authors
James L. Orlando, Matt De Parsia, Corey J. Sanders, Michelle L. Hladik, Jared Frantzich
Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program 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...
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
An initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16 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...
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 D. De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna Williams
Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program
Emergent hypotheses about causes of the pelagic organism decline in the Sacramento–San Joaquin Delta (Delta) indicate that a more complete understanding of the quality of water entering the Delta is needed. Less than half of all pesticides used in the Delta watershed are measured in samples collected for routine monitoring, and with new pesticides continually being registered for use...
Authors
Matthew D. De Parsia, James L. Orlando, Megan M. McWayne, Michelle L. Hladik
Increasing neonicotinoid use and the declining butterfly fauna of lowland California Increasing neonicotinoid use and the declining butterfly fauna of lowland California
The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative...
Authors
Matthew L. Forister, Bruce Cousens, Joshua G. Harrison, Kayce Anderson, James H. Thorne, Dave Waetjen, Chris C. Nice, Matt De Parsia, Michelle Hladik, Robert Meese, Heidi van Vliet, Arthur M. Shapiro
Science and Products
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...
Filter Total Items: 15
Concurrent Occurrence of Pesticides and Per- and Polyfluoroalkyl Substances (PFAS) in Agricultural Streams in California, USA Concurrent Occurrence of Pesticides and Per- and Polyfluoroalkyl Substances (PFAS) in Agricultural Streams in California, USA
Per-and polyfluoroalkyl substances (PFAS) are frequently found in streams, with most research focusing on urban sources of PFAS to surface water (e.g., firefighting foams, industrial releases, and wastewater treatment plant discharges). Pesticide applications are an under-investigated source of PFAS to streams in both agricultural and urban areas. There are few studies that analyze the...
Organic Contaminants at Trespass Cannabis Grows on Federal Land in California, USA Organic Contaminants at Trespass Cannabis Grows on Federal Land in California, USA
Despite the legalization of recreational cannabis in California, illegal cultivation persists, particularly on public lands (trespass grows). These operations often divert water unlawfully and apply unauthorized chemical fertilizers and pesticides. This dataset reports the presence, and in some cases concentrations, of persistent chemicals in soil, water, and sediment in nearby streams...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2024 Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2024
Zooplankton samples were collected in the summer/fall of 2024 at multiple sites in the Sacramento River, Yolo Bypass, and Cache Slough Region of California and analyzed for a suite of 160 current-use pesticides and pesticide degradates by the U.S. Geological Survey Organic Chemistry Research Laboratory. Samples were collected at two sites in the Bypass, at a comparison site on the...
Pesticide Concentrations Measured During In-Situ Active Water Sampler Testing in Solano County, California, 2023 Pesticide Concentrations Measured During In-Situ Active Water Sampler Testing in Solano County, California, 2023
A novel U.S. Geological Survey-developed active water sampler was deployed at Ulatis Creek in Solano County, California for 24 hours from November 15, 2023 to November 16, 2023. Discrete surface water samples were collected at the start and end points of the active water sampler deployment interval for comparison to the active water sampler. Samples from the active water sampler and the...
Pesticide concentrations in multiple stream matrices collected near Mead, Nebraska, 2022 Pesticide concentrations in multiple stream matrices collected near Mead, Nebraska, 2022
The AltEn bioenergy plant (Mead, Nebraska, USA) previously (2015 to 2021) generated ethanol from almost 100% unused/expired treated corn seeds. This use of treated corn seeds as a feedstock for ethanol production resulted in accumulation of large amounts of contaminated wastewater and solid residue at the plant, a portion of which was applied to surrounding farmland. To better understand...
6PPD-quinone concentrations in the Sacramento-San Joaquin Delta, California, 2018-2024 6PPD-quinone concentrations in the Sacramento-San Joaquin Delta, California, 2018-2024
The Sacramento-San Joaquin Delta is a crucial river delta that supplies a significant portion of California's freshwater for agricultural and residential use and serves as critical habitat for numerous state and federally listed species of concern. In several areas, urban stormwater drains discharge directly into the Delta. 6PPD-quinone (6PPD-Q, 2-anilo-5-[(4-methylpentan-2- yl)amino...
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...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2022 and 2023 Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River, Yolo Bypass, and Cache Slough Region, California, 2022 and 2023
Zooplankton samples were collected in the summer/fall of 2022 and 2023 at multiple sites in the Sacramento River, Yolo Bypass, and Cache Slough Region of California and analyzed for a suite of 160 current-use pesticides and pesticide degradates by the U.S. Geological Survey Organic Chemistry Research Laboratory. In 2022 samples were collected at two sites in the Bypass and at a...
Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2021 Pesticide Concentrations Measured in Zooplankton Samples Collected from the Sacramento River and Yolo Bypass, California, 2021
Zooplankton samples were collected at one site upstream of the Yolo Bypass in Northern California, three sites within the Bypass, and at a comparison site on the Sacramento River below the city of Sacramento and analyzed for a large suite of current-use pesticides and degradates. Samples were collected every two weeks from early August 2021 to mid-October 2021. Samples were collected by...
Results from U.S. Geological Survey Environmental Health Food Resources Lifecycle Integrated Science Team, Graton Pesticides (GRAPE) Study, in Graton, California, April–May 2021 Results from U.S. Geological Survey Environmental Health Food Resources Lifecycle Integrated Science Team, Graton Pesticides (GRAPE) Study, in Graton, California, April–May 2021
In the spring of 2021, six households with private wells were selected throughout Graton, California, based on proximity to agriculture (within one mile of agriculture), well depth (i.e., less than 150 feet in depth), and well type (i.e., dug versus drilled). Silicone bands were deployed for 30 days at outdoor locations at each household to passively sample pesticides in ambient air. On...
Naled and dichlorvos in water and aquatic organisms from a canal and rice fields near Sacramento, California Naled and dichlorvos in water and aquatic organisms from a canal and rice fields near Sacramento, California
Ultra-low volumes of naled are applied by aircraft over rice fields and canals to reduce adult mosquito populations near Sacramento, California. Each summer, the pesticide is applied approximately 7-10 times between July and October. Naled and its major degradate (dichlorvos) were quantified in water, biofilm, and invertebrates following aerial applications. In 2020, samples were...
Current-use pesticides, nutrients, chloride, and metals in ponds and stormwater basins of the New Jersey Pinelands, 2018-20 Current-use pesticides, nutrients, chloride, and metals in ponds and stormwater basins of the New Jersey Pinelands, 2018-20
The data presented in this data release include concentrations of current-use pesticides, nutrients, chloride, and metals in surface water collected from 60 wetlands including natural ponds, excavated ponds (Xponds), and stormwater basins in the New Jersey Pinelands, 2018-20. Site information, basic water-quality parameters, and method information also are included.
Effects of flow on pesticides in water and zooplankton in the northern Sacramento-San Joaquin Delta Effects of flow on pesticides in water and zooplankton in the northern Sacramento-San Joaquin Delta
Zooplankton are a key food source for juvenile fishes in estuaries worldwide, including California’s Sacramento–San Joaquin Delta (hereafter Delta); both zooplankton quality and quantity are critical to ecosystem health. Zooplankton may be affected by pesticides in water and the food web, and the Delta is known to contain complex pesticide mixtures. In this study, we evaluated pesticide
Authors
James Orlando, Laura Twardochleb, David Bosworth, Michelle L. Hladik, Corey Sanders, Matt De Parsia, Brittany E. Davis
Identifying organic contaminants at trespass cannabis grows on federal land in California, USA Identifying organic contaminants at trespass cannabis grows on federal land in California, USA
Despite the legalization of recreational cannabis in California, USA, illegal cannabis cultivation remains pervasive, partly through the establishment of illegal cultivation on public lands (trespass grows). These operations often illegally divert water for irrigation and perform unauthorized applications of chemical fertilizers and pesticides. This work investigates a broad suite of...
Authors
Gabrielle Pecora Black, Matt De Parsia, Matthew Uychutin, Mourad W. Gabriel, Ivan Medel, Greta Wengert, Clayton D. Raines, Dana W. Kolpin, Laura E. Hubbard, Michelle L. Hladik
Pesticide concentrations in multiple physical and biological stream matrices are impacted by a bioenergy production facility receiving pesticide coated corn seeds Pesticide concentrations in multiple physical and biological stream matrices are impacted by a bioenergy production facility receiving pesticide coated corn seeds
Insecticide and fungicide seed coatings have become prevalent in conventional agriculture in recent decades. From 2015 to 2021, the AltEn bioenergy plant (Mead, Nebraska, USA) generated ethanol from almost 100% unused/expired treated corn seeds. This use of these seeds for ethanol production resulted in the accumulation of large amounts of contaminated wastewater and solid residue, a...
Authors
Michelle L. Hladik, Dana W. Kolpin, Matthew D. De Parsia, Daniel D. Snow, Shannon Bartelt-Hunt, Brenda Densmore, Laura E. Hubbard, David L. Rus, Jonathan J. Spurgeon, Brittany G. Perrotta, Karen A. Kidd, Johanna M. Kraus, Carrie E. Givens, Christopher James Kotalik, David Walters
6PPD-quinone in water from the San Francisco-San Joaquin Delta, California, 2018-2024 6PPD-quinone in water from the San Francisco-San Joaquin Delta, California, 2018-2024
The Sacramento-San Joaquin Delta (Delta) is an expansive river delta supplying a large portion of California’s fresh water for agriculture and residential use, and it is also an area of critical habitat for numerous state and federally listed species of concern. In many locations, urban stormwater flows directly into the Delta. 6PPD-quinone (6PPD-Q), an ozonation byproduct of a tire...
Authors
Gabrielle Pecora Black, Matthew D. De Parsia, Matthew Uychutin, Rachael F. Lane, James Orlando, Michelle L. Hladik
Pesticide concentrations of surface water and suspended sediment in Yolo By-Pass and Cache Slough Complex, California, 2019–2021 Pesticide concentrations of surface water and suspended sediment in Yolo By-Pass and Cache Slough Complex, California, 2019–2021
Managed flow pulses in the north Sacramento-San Joaquin Delta are an adaptive management tool used in efforts to enhance food availability in delta smelt (Hypomesus transpacificus) habitat as part of the North Delta Food Subsidies Action. The California Department of Water Resources (DWR) monitors non-managed seasonal and local flow pulses and managed flow pulses from agricultural...
Authors
Matthew Uychutin, James L. Orlando, Michelle L. Hladik, Corey J. Sanders, Michael S. Gross, Matthew D. De Parsia, Elisabeth M. LaBarbera, Laura Twardochleb, Brittany E. Davis
Methods of analysis—Determination of pesticides in filtered water and suspended sediment using liquid chromatography- and gas chromatography-tandem mass spectrometry Methods of analysis—Determination of pesticides in filtered water and suspended sediment using liquid chromatography- and gas chromatography-tandem mass spectrometry
The widespread application of pesticides in agricultural and urban areas leads to their presence in surface waters. Presence of these biologically active chemicals in environmental waters potentially has adverse effects on nontarget organisms. To better understand the environmental fate of these contaminants, a robust method to capture chemicals with wide-ranging physicochemical...
Authors
Michael S. Gross, Corey J. Sanders, Matthew D. De Parsia, Michelle L. Hladik
Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19 Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19
Passive sampler devices were deployed in six northern California streams five times between November 2018 and December 2019 to measure the presence or absence of current-use pesticides in surface water. In the targeted areas, there are reported pesticide uses for agriculture, commercial forestry, and rights of way maintenance along with unreported pesticide use at private residences and...
Authors
Matthew D. De Parsia, James L. Orlando, Michelle L. Hladik
Pesticide concentrations associated with augmented flow pulses in the Yolo Bypass and Cache Slough Complex, California Pesticide concentrations associated with augmented flow pulses in the Yolo Bypass and Cache Slough Complex, California
Surface-water and suspended-sediment samples were collected and analyzed by the U.S. Geological Survey for multiple current-use pesticides and pesticide degradates approximately every 2 weeks at up to five sites in the Yolo Bypass and Cache Slough Complex before, during, and after augmented flow pulses in summer and fall 2016 and 2018 as well as during ambient flow conditions in summer...
Authors
James L. Orlando, Matt De Parsia, Corey J. Sanders, Michelle L. Hladik, Jared Frantzich
Pesticide mixtures in the Sacramento–San Joaquin Delta, 2016–17: Results from year 2 of the Delta Regional Monitoring Program 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...
Authors
Matthew D. De Parsia, Emily E. Woodward, James L. Orlando, Michelle L. Hladik
An initial comparison of pesticides and amphibian pathogens between natural and created wetlands in the New Jersey Pinelands, 2014–16 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...
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 D. De Parsia, Amaryl Griggs, Megan McWayne-Holmes, Naisargi Patel, Corey Sanders, Yesha Shrestha, Sean M. Stout, Brianna Williams
Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program
Emergent hypotheses about causes of the pelagic organism decline in the Sacramento–San Joaquin Delta (Delta) indicate that a more complete understanding of the quality of water entering the Delta is needed. Less than half of all pesticides used in the Delta watershed are measured in samples collected for routine monitoring, and with new pesticides continually being registered for use...
Authors
Matthew D. De Parsia, James L. Orlando, Megan M. McWayne, Michelle L. Hladik
Increasing neonicotinoid use and the declining butterfly fauna of lowland California Increasing neonicotinoid use and the declining butterfly fauna of lowland California
The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative...
Authors
Matthew L. Forister, Bruce Cousens, Joshua G. Harrison, Kayce Anderson, James H. Thorne, Dave Waetjen, Chris C. Nice, Matt De Parsia, Michelle Hladik, Robert Meese, Heidi van Vliet, Arthur M. Shapiro