View looking upstream from the hiking trail at Dinosaur national monument. Shows Brown's Park, our camp and the boats, beach, river, scenic background with cottonwoods
Melissa A Lombard
Melissa Lombard is a Research Hydrologist in the New England Water Science Center.
In the broadest sense, Melissa's work is at the intersection of humans and the environment. Her research interests include connecting environmental geochemistry with human and ecosystem health and using machine learning models as a tool to understand, estimate, and predict contaminant occurrence and water availability and use. Much of her work has focused on building and using models as a tool for understanding and predicting trace element occurrence in groundwater. She enjoys collaborating with epidemiologists and public health scientists to link the occurrence of these elements to human health outcomes. Other research interests include the impacts of climate change on water quality, water availability, and human health, and the environmental health effects from the reuse of materials from unconventional oil and gas development. Her previous professional experience includes running analytical instruments in clean labs, overseeing groundwater sampling activities at contaminated sites, and collecting atmospheric mercury samples. Previous research has included examining the potential human health effects from exposure to biodiesel and petroleum diesel emissions, the occurrence of mercury in rainwater, and the occurrence of pesticides and herbicides in groundwater. She has also worked with K-12 science educators and taught college level courses in geology and environmental science.
Professional Experience
Research Hydrologist, U.S. Geological Survey, New England Water Science Center, 2022 to Present
Hydrologist, U.S. Geological Survey, New England Water Science Center, 2017 to 2022
Education and Certifications
Ph.D. Earth and Environmental Science, University of New Hampshire, 2012
M.S. Geology, Rensselaer Polytechnic Institute, 2002
B.A. Geoscience, William Smith College, 1995
Affiliations and Memberships*
Licensed Professional Geologist, State of New Hampshire, 2015
Science and Products
Coproduced Science Linking Environmental and Public-Health Data to Evaluate Drinking Water Arsenic Exposure on Birth Outcomes
Preliminary Research into the Causes of Iron Fouling in Water at Roadway Construction Sites
Towards Understanding the Impact of Drought on the Arsenic Hazard for the Private Domestic Well Population in the United States
Linking environmental and public health data to evaluate health effects of arsenic exposure from domestic and public supply wells
Data and model archive used to model and map lithium concentrations in groundwater sources of drinking water in the conterminous United States
U.S. Streamflow Drought During the Last Century: annual drought and low flow metrics, annual climate, and trends for the periods 1921-2020, 1951-2020 and 1981-2020
Geospatial Fabric for National Hydrologic Modeling, version 1.1
Data used to model and map arsenic concentration exceedances in private wells throughout the conterminous United States for human health studies
Datasets for assessing the impact of drought on arsenic exposure from private domestic wells in the conterminous United States
Iron fouling data associated with drainage from roadway sites constructed with rock fill in New Hampshire
Concentrations of arsenic in water from public supply and domestic wells in New Hampshire
Testing dataset for independent analysis of New Hampshire arsenic model
View looking upstream from the hiking trail at Dinosaur national monument. Shows Brown's Park, our camp and the boats, beach, river, scenic background with cottonwoods
A view looking down on the river from the hills above camp. View is upstream and shows a nice river meander with a point bar and scenic hills in the background. This is in Brown's Park.
A view looking down on the river from the hills above camp. View is upstream and shows a nice river meander with a point bar and scenic hills in the background. This is in Brown's Park.
The scenic view of the Gates of Lodore from Brown's Park. The Green River through Brown's Park is very calm, slow moving water, with canyon walls and up ahead looms the scar where the river has eroded it's way down through the mountains.
The scenic view of the Gates of Lodore from Brown's Park. The Green River through Brown's Park is very calm, slow moving water, with canyon walls and up ahead looms the scar where the river has eroded it's way down through the mountains.
A great examples of the crossbeds in the Uinta Formation, a quarzite dating back to the PreCambrian, on a beautiful sunny morning with mist hanging above the river as the sun rises.
A great examples of the crossbeds in the Uinta Formation, a quarzite dating back to the PreCambrian, on a beautiful sunny morning with mist hanging above the river as the sun rises.
A close-up of a bald eagle hanging out on a cliff along the Green River in swallow canyon
A close-up of a bald eagle hanging out on a cliff along the Green River in swallow canyon
Two of the SCREE rafts heading downstream through Swallow Canyon
Two of the SCREE rafts heading downstream through Swallow Canyon
A group of cliff swallow nests made from mud in the river in Swallow Canyon. Many of the nests have birds in them and can be identified by their yellow beaks sticking out.
A group of cliff swallow nests made from mud in the river in Swallow Canyon. Many of the nests have birds in them and can be identified by their yellow beaks sticking out.
A flock of pelicans in the water in Brown's Park.
A flock of pelicans in the water in Brown's Park.
View looking upstream at Flaming Gorge Dam from the boat launch area
View looking upstream at Flaming Gorge Dam from the boat launch area
View looking downstream from just below the boat launch at Flaming Gorge Dam.
View looking downstream from just below the boat launch at Flaming Gorge Dam.
Estimating lithium concentrations in groundwater used as drinking water for the conterminous United States
Contribution of arsenic and uranium in private wells and community water systems to urinary biomarkers in US adults: The Strong Heart Study and the Multi-Ethnic Study of Atherosclerosis
Cross-sectional associations between drinking water arsenic and urinary inorganic arsenic in the US: NHANES 2003-2014
A hydrologic perspective of major U.S. droughts
Going beyond low flows: Streamflow drought deficit and duration illuminate distinct spatiotemporal drought patterns and trends in the U.S. during the last century
Arsenic in private well water and birth outcomes in the United States
Perfluoroalkyl and polyfluoroalkyl substances in groundwater used as a source of drinking water in the eastern United States
In 2019, 254 samples were collected from five aquifer systems to evaluate per- and polyfluoroalkyl substance (PFAS) occurrence in groundwater used as a source of drinking water in the eastern United States. The samples were analyzed for 24 PFAS, major ions, nutrients, trace elements, dissolved organic carbon (DOC), volatile organic compounds (VOCs), pharmaceuticals, and tritium. Fourteen of the 24
Associations between private well water and community water supply arsenic concentrations in the conterminous United States
Machine learning models of arsenic in private wells throughout the conterminous United States as a tool for exposure assessment in human health studies
Assessing the impact of drought on arsenic exposure from private domestic wells in the conterminous United States
A multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA
Estimating domestic well locations and populations served in the contiguous U.S. for years 2000 and 2010
Non-USGS Publications**
**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.
Science and Products
- Science
Coproduced Science Linking Environmental and Public-Health Data to Evaluate Drinking Water Arsenic Exposure on Birth Outcomes
U.S. Geological Survey (USGS) scientists teamed up with public-health epidemiologists to probe for associations between arsenic in drinking water and human-birth outcomes. They reported a modest inverse relation between birth weight and arsenic exposure. Findings indicate that future research efforts using individual-level exposure data such as measured arsenic concentrations in tap water could...Preliminary Research into the Causes of Iron Fouling in Water at Roadway Construction Sites
The USGS and the New Hampshire Department of Transportation are conducting preliminary research into the causes of iron fouling in water at roadway construction sites where blasted bedrock is used as on-site fill material.Towards Understanding the Impact of Drought on the Arsenic Hazard for the Private Domestic Well Population in the United States
The USGS and the Centers for Disease Control and Prevention are examining the potential effects of droughts on the arsenic hazard in private well water across the Nation.Linking environmental and public health data to evaluate health effects of arsenic exposure from domestic and public supply wells
Everyone needs clean drinking water in order to thrive. The US EPA and public water purveyors in the US work together in adherence with the Safe Drinking Water Act to make water safe for public consumption. The recent media coverage of lead in public drinking water supplies in Flint, Michigan, and schools in many cities with aging infrastructure throughout the US has raised public awareness of dri - Data
Data and model archive used to model and map lithium concentrations in groundwater sources of drinking water in the conterminous United States
This data release contains data used to develop models and maps that estimate the occurrence of lithium in groundwater used as drinking water throughout the conterminous United States. An extreme gradient boosting model was developed to estimate the most probable lithium concentration category (≤4, >4 to ≤10, >10 to ≤30, or >30 µg/L). The model uses lithium concentration data from wells located thU.S. Streamflow Drought During the Last Century: annual drought and low flow metrics, annual climate, and trends for the periods 1921-2020, 1951-2020 and 1981-2020
This dataset contains annual flow metrics quantifying drought and low streamflows for USGS GAGES-2 gages in the contiguous U.S. satisfying data completeness checks for the periods 1921-2020, 1951-2020, and 1981-2020. The dataset also contains annual climate variables from the USGS Monthly Water Balance Model (MWBM). The dataset provides trend analysis outputs for annual drought and low flow metricGeospatial Fabric for National Hydrologic Modeling, version 1.1
This U.S. Geological Survey (USGS) data release consists of two hydrographic datasets with spatial modeling units consistent with the National Hydrologic Model (NHM) Geospatial Fabric for National Hydrologic Modeling (abbreviated within this document as GFv1, Viger and Bock, 2014). The two datasets found as subpages to this landing page are 1) the GIS (geographic information system) features of thData used to model and map arsenic concentration exceedances in private wells throughout the conterminous United States for human health studies
This data release contains data used to develop models and maps that estimate the probabilities of exceeding various thresholds of arsenic concentrations in private domestic wells throughout the conterminous United States. Three boosted regression tree (BRT) models were developed separately to estimate the probability of private well arsenic concentrations exceeding 1, 5, and 10 micrograms per litDatasets for assessing the impact of drought on arsenic exposure from private domestic wells in the conterminous United States
Documented in this data release are data used to model and map the probability of arsenic being greater than 10 micrograms per liter in private domestic wells throughout the conterminous United States during drought conditions (Lombard and others, 2020). The model used to predict the probability of arsenic exceeding 10 micrograms per liter in private domestic wells was previously developed and docIron fouling data associated with drainage from roadway sites constructed with rock fill in New Hampshire
This data release contains files that are associated with the publication 'Understanding and predicting iron fouling associated with drainage from roadway sites constructed with rock-fill in New Hampshire, USA'. Each zipped file contains a data table or raster file and an associated metadata file. IronFoulingCutFillData.zip contains a .csv file and .xml metadata file related to the roadcut and rocConcentrations of arsenic in water from public supply and domestic wells in New Hampshire
This dataset contains arsenic concentrations from bedrock aquifer wells located throughout New Hampshire and includes public supply wells and domestic supply wells.Testing dataset for independent analysis of New Hampshire arsenic model
Existing multivariate logistic regression models that predict the probabilities of arsenic concentrations at 1, 5, and 10 micrograms per liter in bedrock aquifers of New Hampshire were tested using bedrock wells not included in the model development. This data release contains a table of measured arsenic concentrations and associated model input variables for the model testing dataset. Location - Multimedia
Camp and River in Dinosaur National Monument
View looking upstream from the hiking trail at Dinosaur national monument. Shows Brown's Park, our camp and the boats, beach, river, scenic background with cottonwoods
View looking upstream from the hiking trail at Dinosaur national monument. Shows Brown's Park, our camp and the boats, beach, river, scenic background with cottonwoods
A meander in the Green River at Brown's ParkA view looking down on the river from the hills above camp. View is upstream and shows a nice river meander with a point bar and scenic hills in the background. This is in Brown's Park.
A view looking down on the river from the hills above camp. View is upstream and shows a nice river meander with a point bar and scenic hills in the background. This is in Brown's Park.
Gates of Lodore looming from Brown's ParkThe scenic view of the Gates of Lodore from Brown's Park. The Green River through Brown's Park is very calm, slow moving water, with canyon walls and up ahead looms the scar where the river has eroded it's way down through the mountains.
The scenic view of the Gates of Lodore from Brown's Park. The Green River through Brown's Park is very calm, slow moving water, with canyon walls and up ahead looms the scar where the river has eroded it's way down through the mountains.
Uinta formation on a misty morningA great examples of the crossbeds in the Uinta Formation, a quarzite dating back to the PreCambrian, on a beautiful sunny morning with mist hanging above the river as the sun rises.
A great examples of the crossbeds in the Uinta Formation, a quarzite dating back to the PreCambrian, on a beautiful sunny morning with mist hanging above the river as the sun rises.
Majestic eagleA close-up of a bald eagle hanging out on a cliff along the Green River in swallow canyon
A close-up of a bald eagle hanging out on a cliff along the Green River in swallow canyon
SCREE rafts going through Swallow CanyonTwo of the SCREE rafts heading downstream through Swallow Canyon
Two of the SCREE rafts heading downstream through Swallow Canyon
Cliff Swallow Nests in Swallow CanyonA group of cliff swallow nests made from mud in the river in Swallow Canyon. Many of the nests have birds in them and can be identified by their yellow beaks sticking out.
A group of cliff swallow nests made from mud in the river in Swallow Canyon. Many of the nests have birds in them and can be identified by their yellow beaks sticking out.
Pelicans in Brown's ParkA flock of pelicans in the water in Brown's Park.
A flock of pelicans in the water in Brown's Park.
Immediately downstream of Flaming Gorge DamView looking upstream at Flaming Gorge Dam from the boat launch area
View looking upstream at Flaming Gorge Dam from the boat launch area
Green River Downstream of Flaming Gorge DamView looking downstream from just below the boat launch at Flaming Gorge Dam.
View looking downstream from just below the boat launch at Flaming Gorge Dam.
- Publications
Filter Total Items: 13
Estimating lithium concentrations in groundwater used as drinking water for the conterminous United States
Lithium (Li) concentrations in drinking-water supplies are not regulated in the United States; however, Li is included in the 2022 U.S. Environmental Protection Agency list of unregulated contaminants for monitoring by public water systems. Li is used pharmaceutically to treat bipolar disorder, and studies have linked its occurrence in drinking water to human-health outcomes. An extreme gradient bAuthorsMelissa Lombard, Eric E. Brown, Daniel Saftner, Monica M. Arienzo, Esme Fuller-Thomson, Craig J. Brown, Joseph D. AyotteContribution of arsenic and uranium in private wells and community water systems to urinary biomarkers in US adults: The Strong Heart Study and the Multi-Ethnic Study of Atherosclerosis
BackgroundChronic exposure to inorganic arsenic (As) and uranium (U) in the United States (US) occurs from unregulated private wells and federally regulated community water systems (CWSs). The contribution of water to total exposure is assumed to be low when water As and U concentrations are low.ObjectiveWe examined the contribution of water As and U to urinary biomarkers in the Strong Heart FamilAuthorsMaya Spaur, Ronald A. Glabonjat, Kathrin Schilling, Melissa Lombard, Galvez-Fernandez, Wil Lieberman-Cribbin, Carolyn Hayek, Vesna Ilievski, Olgica Balac, Chiugo Izuchukwu, Kevin Patterson, Anirban Basu, Benjamin Bostick, Qixuan Chen, Tiffany Sanchez, Ana Navas-Acien, Anne E NigraCross-sectional associations between drinking water arsenic and urinary inorganic arsenic in the US: NHANES 2003-2014
Background: Inorganic arsenic is a potent carcinogen and toxicant associated with numerous adverse health outcomes. The contribution of drinking water from private wells and regulated community water systems (CWSs) to total inorganic arsenic exposure is not clear. Objectives: To determine the association between drinking water arsenic estimates and urinary arsenic concentrations in the 2003-2014AuthorsMaya Spaur, Melissa Lombard, Joseph D. Ayotte, Benjamin C. Bostick, Steven N. Chillrud, Ana Navas-Acien, Anne E. NigraA hydrologic perspective of major U.S. droughts
Drought is a recurring natural hazard that has substantial human and environmental impacts. Given continued global warming and associated climate change, there is concern that droughts could become more severe and longer lasting. To better monitor and understand drought development and persistence, it is helpful to understand the development and climatic drivers of past droughts. In this study weAuthorsGregory J. McCabe, David M. Wolock, Melissa Lombard, Robert W. Dudley, John Christopher Hammond, Jory Seth Hecht, Glenn A. Hodgkins, Carolyn G. Olson, Roy Sando, Caelan E. Simeone, Michael E. WieczorekGoing beyond low flows: Streamflow drought deficit and duration illuminate distinct spatiotemporal drought patterns and trends in the U.S. during the last century
Streamflow drought is a recurring challenge, and understanding spatiotemporal patterns of past droughts is needed to manage future water resources. We examined regional patterns in streamflow drought metrics and compared these metrics to low flow timing and magnitude using long-term daily records for 555 minimally disturbed watersheds. For each streamgage, we calculated streamflow drought durationAuthorsJohn C. Hammond, Caelan E. Simeone, Jory Seth Hecht, Glenn A. Hodgkins, Melissa Lombard, Gregory J. McCabe, David M. Wolock, Michael Wieczorek, Carolyn G Olson, Todd Caldwell, Robert W. Dudley, Adam N. PriceArsenic in private well water and birth outcomes in the United States
BackgroundPrenatal exposure to drinking water with arsenic concentrations >50 μg/L is associated with adverse birth outcomes, with inconclusive evidence for concentrations ≤50 μg/L. In a collaborative effort by public health experts, hydrologists, and geologists, we used published machine learning model estimates to characterize arsenic concentrations in private wells—federally unregulated for driAuthorsCatherine Bulka, Molly Scannell Bryan, Melissa Lombard, Scott Bartell, Daniel Jones, Paul M. Bradley, Veronica Vieira, Debra Silverman, Michael J. Focazio, Patricia Toccalino, Johnni Daniel, Lorraine C. Backer, Joseph D. Ayotte, Matthew O. Gribble, Maria ArgosPerfluoroalkyl and polyfluoroalkyl substances in groundwater used as a source of drinking water in the eastern United States
In 2019, 254 samples were collected from five aquifer systems to evaluate per- and polyfluoroalkyl substance (PFAS) occurrence in groundwater used as a source of drinking water in the eastern United States. The samples were analyzed for 24 PFAS, major ions, nutrients, trace elements, dissolved organic carbon (DOC), volatile organic compounds (VOCs), pharmaceuticals, and tritium. Fourteen of the 24
AuthorsPeter B. McMahon, Andrea K. Tokranov, Laura M. Bexfield, Bruce D. Lindsey, Tyler D. Johnson, Melissa Lombard, Elise WatsonAssociations between private well water and community water supply arsenic concentrations in the conterminous United States
Geogenic arsenic contamination typically occurs in groundwater as opposed to surface water supplies. Groundwater is a major source for many community water systems (CWSs) in the United States (US). Although the US Environmental Protection Agency sets the maximum contaminant level (MCL enforceable since 2006: 10 μg/L) for arsenic in CWSs, private wells are not federally regulated. We evaluated counAuthorsMaya Spaur, Melissa Lombard, Joseph D. Ayotte, David Harvey, Benjamin Bostick, Steven Chillrud, Ana Navas-Acien, Anne E NigraMachine learning models of arsenic in private wells throughout the conterminous United States as a tool for exposure assessment in human health studies
Arsenic from geologic sources is widespread in groundwater within the United States (U.S.). In several areas, groundwater arsenic concentrations exceed the U.S. Environmental Protection Agency maximum contaminant level of 10 μg per liter (μg/L). However, this standard applies only to public-supply drinking water and not to private-supply, which is not federally regulated and is rarely monitored. AAuthorsMelissa Lombard, Molly Scannell Bryan, Daniel Jones, Catherine Bulka, Paul M. Bradley, Lorraine C. Backer, Michael J. Focazio, Debra T. Silverman, Patricia Toccalino, Maria Argos, Matthew O. Gribble, Joseph D. AyotteAssessing the impact of drought on arsenic exposure from private domestic wells in the conterminous United States
This study assesses the potential impact of drought on arsenic exposure from private domestic wells by using a previously developed statistical model that predicts the probability of elevated arsenic concentrations (>10 μg per liter) in water from domestic wells located in the conterminous United States (CONUS). The application of the model to simulate drought conditions used systematically reduceAuthorsMelissa Lombard, Johnni Daniel, Zuha Jeddy, Lauren Hay, Joseph D. AyotteA multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA
Factors affecting iron fouling in wet areas adjacent to roadways were investigated by collecting field rock cut and aqueous physicochemical data; developing exploratory predictive models; and developing geochemical models. Basic data included the identification of iron fouling from aerial imagery and field visits at 374 New Hampshire rock cut locations, and their associated rock-fill sites. BasedAuthorsMelissa Lombard, Pamela J. Lombard, Craig J. Brown, James DegnanEstimating domestic well locations and populations served in the contiguous U.S. for years 2000 and 2010
Domestic wells provide drinking water supply for approximately 40 million people in the United States. Knowing the location of these wells, and the populations they serve, is important for identifying heavily used aquifers, locations susceptible to contamination, and populations potentially impacted by poor-quality groundwater. The 1990 census was the last nationally consistent survey of a home’sAuthorsTyler D. Johnson, Kenneth Belitz, Melissa LombardNon-USGS Publications**
Martin, N., Lombard, M., Jensen, M., Kelley, P., Pratt, T., Traviss, N., (2017), Effect of biodiesel fuel and nonroad heavy duty diesel engine technology on “real world” particulate matter emissions, composition and cytotoxicity, Science of the Total Environment, 586:409-418, doi: 10.1016/j.scitotenv.2016.12.041Gengarelly, L., Graham, K., Hopkins, B., Lombard M., (2017), Dive in! Immersion in Science Practices for High School Students, National Science Teachers Association Press, ISBN 9781941316290.Traviss, N., Li, M., Lombard, M., Thelen, B.A., Palmer, B.C., Poynter, M., Mossman, B., Holmen, B., Fukagawa, N. (2014), Petrodiesel and waste grease biodiesel (B20) emission particles: Characterization and effects on lung epithelial cells and macrophages, Air Quality, Atmosphere and Health, 7(1), 59-70.Lombard, M., Bryce, J., Mao, H., Talbot, R.W., (2011), Mercury deposition in southern New Hampshire, 2006-2009, Atmos. Chem. Phys., 11, 7657–7668, www.atmos-chem-phys.net/11/7657/2011/ doi:10.5194/acp-11-7657-2011.Talbot, R., Mao, H., Feddersen, D., Smith, M., Kim, S.Y., Sive, B., Haase, K., Ambrose, J., Zhou, Y., Russo, R. (2011), Comparison of particulate mercury measured with manual and automated methods, Atmosphere, 2(1), 1-20; doi:10.3390/atmos20100001.Phillips, P.J., Eckhardt, D.A., Smith, M.A., Rosenmann, L. (2000). Pesticides and their Metabolites in Selected Surface-water Public Supplies in New York State, 1999, USGS Water Resources Investigations Report 00-4119.**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.
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*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government