A Research Hydrologist with the USGS New Jersey Water Science Center, specializing in investigating the occurrence and mobility of radon and radium since 1985, has been the national leader in defining the occurrence of short-lived radium-224 in groundwater. His recent work has expanded to the occurrence of a broad suite of "emerging" contaminants in groundwater and surface water.
Led the radionuclide occurrence and mobility assessment for the National Water Quality Assessment (NAWQA) program, with focus on National Radium occurrence. He has co-authored the NAWQA cycle III 10-year research plan for radionuclides. He worked on methods development for radionuclide analyses, included in Standard Methods, and analytical methods challenges of complex matrices including high TDS natural waters and waste brines. He has worked with isotopes as tracers of ground-water movement, including use of tritium, helium-3, and stable isotopes of nitrogen and strontium. He has been working on characterizing waste streams from septic tanks affecting ground-water quality and sewage discharge affecting surface water, as well as examining the effect of various treatment systems for these compounds. He has also been working on toxicology of sediments. He has helped design, test and implement "ultra-clean" ground-water sampling protocols for trace elements, including mercury, and is working on defining mercury distribution in the environment for coastal regions. He has expanded into “emerging” contaminants in ground/surface water, including various short-lived radionuclides, organic compounds, and the “species” of mercury and arsenic. He has designed studies to document the effects of natural isotope variations on variability in gross alpha-particle activity in ground water and effects of holding time after sample collection.
He has more than 65 full length publications and more than 100 abstracts, mostly devoted to radionuclide occurrence and mercury chemistry.
Education and Certifications
MS in Geology, Ohio State University, thesis on strontium isotopes as groundwater flow tracers
Affiliations and Memberships*
USGS NAWQA Program Trace-Element Synthesis Team on radionuclide occurrence
NIEHS (National Institute Environmental Health & Safety) Superfund Basic Research Program Committee (SBRP)
American Water Works Assoc. Research Foundation (AWWARF) Radionuclide Technical Advisory Committee
Technical advisor to the USGS NWQL (National Water Quality Laboratory) to the radionuclide and tritium-helium analytical services and associated contracts
Collaborates with researchers at local universities and serves as a committee member for graduate student candidates or as senior project advisor
Honors and Awards
Recipient of American Water Works Assoc. Researcher of the Year (2007, NJ Chapter).
Won the USGS Report of the Year Award for the Northeastern USA sparking EPA’s efforts to define occurrence of radium.
Abstracts and Presentations
One of three authors cited for radionuclide studies by USEPA in the Radionuclide Rule of 2000 and the accompanying Radionuclide NODA (Notice of Data Availability).
Science and Products
Geochemical and mineralogic investigation of elevated arsenic and trace element concentrations in glauconitic soils and sediments of the New Jersey Inner Coastal Plain
The U.S. Geological Survey New Jersey Water Science Center (USGS NJWSC) in cooperation with the New Jersey Department of Environmental Protection (NJDEP) has assembled this data release in support of ongoing USGS and NJDEP evaluations related to the occurrence and distribution of elevated trace elements, particularly arsenic (As) and vanadium (V), in Inner Coastal Plain soils and sediments of New
Data for Radium Mobility and the Age of Groundwater in Public-drinking-water Supplies from the Cambrian-Ordovician Aquifer System, North-Central USA
High radium (Ra) concentrations in potable portions of the Cambrian-Ordovician (C-O) aquifer system were investigated using water-quality data and environmental tracers ( 3H, 3Hetrit, SF6 , 14C and 4Herad) of groundwater age from 80 public-supply wells (PSWs). Groundwater ages were estimated by calibration of tracers to lumped parameter models and ranged from modern (1 Myr) in the most downgradien
Filter Total Items: 62
Gross alpha-particle activity and high 226Ra concentrations do not correspond with high 210Po in the Atlantic and Gulf Coastal Plain aquifers of the United States
210Po, which is of human-health concern based on lifetime ingestion cancer risk, is indirectly regulated in drinking water through the U.S. Environmental Protection Agency’s gross alpha-particle activity (GAPA) maximum contaminant level of 15 pCi/L (picocuries per liter). This regulation requires independent measurement of 226Ra for samples exceeding the GAPA screening level of 5 pCi/L. There is n
Authors
Zoltan Szabo, Charles A. Cravotta, Paul Stackelberg, Kenneth Belitz
Relation between road-salt application and increasing radium concentrations in a low-pH aquifer, southern New Jersey
The Kirkwood–Cohansey aquifer in southern New Jersey is an important source of drinking-water supplies, but the availability of the resource is limited in some areas by high concentrations of radium, a potential carcinogen at elevated concentrations. Radium (226Ra plus 228Ra) concentrations from a network of 25 drinking-water wells showed a statistically significant increase over a decadal time sc
Authors
Bruce D. Lindsey, Charles A. Cravotta, Zoltan Szabo, Kenneth Belitz, Paul Stackelberg
Occurrence and geochemistry of lead-210 and polonium-210 radionuclides in public-drinking-water supplies from principal aquifers of the United States
On the basis of lifetime cancer risks, lead-210 (210Pb) and polonium-210 (210Po) ≥ 1.0 and 0.7 pCi/L (picocuries per liter), respectively, in drinking-water supplies may pose human-health concerns. 210Pb and 210Po were detected at concentrations greater than these thresholds at 3.7 and 1.5%, respectively, of filtered untreated groundwater samples from 1263 public-supply wells in 19 principal aquif
Authors
Zoltan Szabo, Paul Stackelberg, Charles A. Cravotta
The relation of geogenic contaminants to groundwater age, aquifer hydrologic position, water type, and redox conditions in Atlantic and Gulf Coastal Plain aquifers, eastern and south-central USA
Groundwater age distributions developed from carbon-14 (14C), tritium (3H), and helium-4 (4He) concentrations, along with aquifer hydrologic position, water type, and redox conditions, were compared to geogenic contaminants of concern (GCOC) from 252 public-supply wells in six Atlantic and Gulf Coastal Plain unconsolidated-sediment aquifers. Concentrations of one or more GCOCs in 168 (67%) wells
Authors
James R. Degnan, Bruce D. Lindsey, Joseph Patrick Levitt, Zoltan Szabo
Radium mobility and the age of groundwater in public-drinking-water supplies from the Cambrian-Ordovician aquifer system, north-central USA
High radium (Ra) concentrations in potable portions of the Cambrian-Ordovician (C-O) aquifer system were investigated using water-quality data and environmental tracers (3H, 3Hetrit, SF6, 14C and 4Herad) of groundwater age from 80 public-supply wells (PSWs). Groundwater ages were estimated by calibration of tracers to lumped parameter models and ranged from modern (<50 yr) in upgradient, regionall
Authors
Paul E. Stackelberg, Zoltan Szabo, Bryant C. Jurgens
An assessment of mercury in estuarine sediment and tissue in Southern New Jersey using public domain data
Mercury (Hg) is considered a contaminant of global concern for coastal environments due to its toxicity, widespread occurrence in sediment, and bioaccumulation in tissue. Coastal New Jersey, USA, is characterized by shallow bays and wetlands that provide critical habitat for wildlife but share space with expanding urban landscapes. This study was designed as an assessment of the magnitude and dist
Authors
Kara Ng, Zoltan Szabo, Pamela A. Reilly, Julia Barringer, Kelly L. Smalling
Sediment chemistry and toxicity in Barnegat Bay, New Jersey: Pre- and post-Hurricane Sandy, 2012–13
Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especi
Authors
Kristin M. Romanok, Zoltan Szabo, Timothy J. Reilly, Zafer Defne, Neil K. Ganju
Urban development and stream ecosystem health—Science capabilities of the U.S. Geological Survey
Urban development creates multiple stressors that can degrade stream ecosystems by changing stream hydrology, water quality, and physical habitat. Contaminants, habitat destruction, and increasing streamflow variability resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic biota. Understanding how algal, inve
Authors
Pamela A. Reilly, Zoltan Szabo, James F. Coles
Arsenic and radionuclide occurrence and relation to geochemistry in groundwater of the Gulf Coast Aquifer System in Houston, Texas, 2007–11
The U.S. Geological Survey (USGS), in cooperation with the City of Houston, began a study in 2007 to determine concentrations, spatial extent, and associated geochemical conditions that might be conducive for mobility and transport of selected naturally occurring trace elements and radionuclides in the Gulf Coast aquifer system in Houston, Texas. Water samples were collected from 91 municipal supp
Authors
Jeannette H. Oden, Zoltan Szabo
The quality of our nation's waters: water quality in the Principal Aquifers of the Piedmont, Blue Ridge, and Valley and Ridge regions, eastern United States, 1993-2009
The aquifers of the Piedmont, Blue Ridge, and Valley and Ridge regions underlie an area with a population of more than 40 million people in 10 states. The suburban and rural population is large, growing rapidly, and increasingly dependent on groundwater as a source of supply, with more than 550 million gallons per day withdrawn from domestic wells for household use. Water from some of these aquife
Authors
Bruce D. Lindsey, Tammy M. Zimmerman, Melinda J. Chapman, Charles A. Cravotta, Zoltan Szabo
The quality of our Nation's waters: water quality in the Northern Atlantic Coastal Plain surficial aquifer system, Delaware, Maryland, New Jersey, New York, North Carolina, and Virginia, 1988-2009
The surficial aquifer system of the Northern Atlantic Coastal Plain is made up of unconfined aquifers that underlie most of the area. This aquifer system is a critical renewable source of drinking water and is the source of most flow to streams and of recharge to underlying confined aquifers. Millions of people rely on the surficial aquifer system for public and domestic water supply, in particula
Authors
Judith M. Denver, Scott W. Ator, Jeffrey M. Fischer, Douglas C. Harned, Christopher Schubert, Zoltan Szabo
Complex resistivity signatures of ethanol biodegradation in porous media
Numerous adverse effects are associated with the accidental release of ethanol (EtOH) and its persistence in the subsurface. Geophysical techniques may permit non-invasive, real time monitoring of microbial degradation of hydrocarbon. We performed complex resistivity (CR) measurements in conjunction with geochemical data analysis on three microbial-stimulated and two control columns to investigate
Authors
Yves Robert Personna, Lee Slater, Dimitrios Ntarlagiannis, Dale D. Werkema, Zoltan Szabo
Science and Products
- Data
Geochemical and mineralogic investigation of elevated arsenic and trace element concentrations in glauconitic soils and sediments of the New Jersey Inner Coastal Plain
The U.S. Geological Survey New Jersey Water Science Center (USGS NJWSC) in cooperation with the New Jersey Department of Environmental Protection (NJDEP) has assembled this data release in support of ongoing USGS and NJDEP evaluations related to the occurrence and distribution of elevated trace elements, particularly arsenic (As) and vanadium (V), in Inner Coastal Plain soils and sediments of NewData for Radium Mobility and the Age of Groundwater in Public-drinking-water Supplies from the Cambrian-Ordovician Aquifer System, North-Central USA
High radium (Ra) concentrations in potable portions of the Cambrian-Ordovician (C-O) aquifer system were investigated using water-quality data and environmental tracers ( 3H, 3Hetrit, SF6 , 14C and 4Herad) of groundwater age from 80 public-supply wells (PSWs). Groundwater ages were estimated by calibration of tracers to lumped parameter models and ranged from modern (1 Myr) in the most downgradien - Publications
Filter Total Items: 62
Gross alpha-particle activity and high 226Ra concentrations do not correspond with high 210Po in the Atlantic and Gulf Coastal Plain aquifers of the United States
210Po, which is of human-health concern based on lifetime ingestion cancer risk, is indirectly regulated in drinking water through the U.S. Environmental Protection Agency’s gross alpha-particle activity (GAPA) maximum contaminant level of 15 pCi/L (picocuries per liter). This regulation requires independent measurement of 226Ra for samples exceeding the GAPA screening level of 5 pCi/L. There is nAuthorsZoltan Szabo, Charles A. Cravotta, Paul Stackelberg, Kenneth BelitzRelation between road-salt application and increasing radium concentrations in a low-pH aquifer, southern New Jersey
The Kirkwood–Cohansey aquifer in southern New Jersey is an important source of drinking-water supplies, but the availability of the resource is limited in some areas by high concentrations of radium, a potential carcinogen at elevated concentrations. Radium (226Ra plus 228Ra) concentrations from a network of 25 drinking-water wells showed a statistically significant increase over a decadal time scAuthorsBruce D. Lindsey, Charles A. Cravotta, Zoltan Szabo, Kenneth Belitz, Paul StackelbergOccurrence and geochemistry of lead-210 and polonium-210 radionuclides in public-drinking-water supplies from principal aquifers of the United States
On the basis of lifetime cancer risks, lead-210 (210Pb) and polonium-210 (210Po) ≥ 1.0 and 0.7 pCi/L (picocuries per liter), respectively, in drinking-water supplies may pose human-health concerns. 210Pb and 210Po were detected at concentrations greater than these thresholds at 3.7 and 1.5%, respectively, of filtered untreated groundwater samples from 1263 public-supply wells in 19 principal aquifAuthorsZoltan Szabo, Paul Stackelberg, Charles A. CravottaThe relation of geogenic contaminants to groundwater age, aquifer hydrologic position, water type, and redox conditions in Atlantic and Gulf Coastal Plain aquifers, eastern and south-central USA
Groundwater age distributions developed from carbon-14 (14C), tritium (3H), and helium-4 (4He) concentrations, along with aquifer hydrologic position, water type, and redox conditions, were compared to geogenic contaminants of concern (GCOC) from 252 public-supply wells in six Atlantic and Gulf Coastal Plain unconsolidated-sediment aquifers. Concentrations of one or more GCOCs in 168 (67%) wellsAuthorsJames R. Degnan, Bruce D. Lindsey, Joseph Patrick Levitt, Zoltan SzaboRadium mobility and the age of groundwater in public-drinking-water supplies from the Cambrian-Ordovician aquifer system, north-central USA
High radium (Ra) concentrations in potable portions of the Cambrian-Ordovician (C-O) aquifer system were investigated using water-quality data and environmental tracers (3H, 3Hetrit, SF6, 14C and 4Herad) of groundwater age from 80 public-supply wells (PSWs). Groundwater ages were estimated by calibration of tracers to lumped parameter models and ranged from modern (<50 yr) in upgradient, regionallAuthorsPaul E. Stackelberg, Zoltan Szabo, Bryant C. JurgensAn assessment of mercury in estuarine sediment and tissue in Southern New Jersey using public domain data
Mercury (Hg) is considered a contaminant of global concern for coastal environments due to its toxicity, widespread occurrence in sediment, and bioaccumulation in tissue. Coastal New Jersey, USA, is characterized by shallow bays and wetlands that provide critical habitat for wildlife but share space with expanding urban landscapes. This study was designed as an assessment of the magnitude and distAuthorsKara Ng, Zoltan Szabo, Pamela A. Reilly, Julia Barringer, Kelly L. SmallingSediment chemistry and toxicity in Barnegat Bay, New Jersey: Pre- and post-Hurricane Sandy, 2012–13
Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especiAuthorsKristin M. Romanok, Zoltan Szabo, Timothy J. Reilly, Zafer Defne, Neil K. GanjuUrban development and stream ecosystem health—Science capabilities of the U.S. Geological Survey
Urban development creates multiple stressors that can degrade stream ecosystems by changing stream hydrology, water quality, and physical habitat. Contaminants, habitat destruction, and increasing streamflow variability resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic biota. Understanding how algal, inveAuthorsPamela A. Reilly, Zoltan Szabo, James F. ColesArsenic and radionuclide occurrence and relation to geochemistry in groundwater of the Gulf Coast Aquifer System in Houston, Texas, 2007–11
The U.S. Geological Survey (USGS), in cooperation with the City of Houston, began a study in 2007 to determine concentrations, spatial extent, and associated geochemical conditions that might be conducive for mobility and transport of selected naturally occurring trace elements and radionuclides in the Gulf Coast aquifer system in Houston, Texas. Water samples were collected from 91 municipal suppAuthorsJeannette H. Oden, Zoltan SzaboThe quality of our nation's waters: water quality in the Principal Aquifers of the Piedmont, Blue Ridge, and Valley and Ridge regions, eastern United States, 1993-2009
The aquifers of the Piedmont, Blue Ridge, and Valley and Ridge regions underlie an area with a population of more than 40 million people in 10 states. The suburban and rural population is large, growing rapidly, and increasingly dependent on groundwater as a source of supply, with more than 550 million gallons per day withdrawn from domestic wells for household use. Water from some of these aquifeAuthorsBruce D. Lindsey, Tammy M. Zimmerman, Melinda J. Chapman, Charles A. Cravotta, Zoltan SzaboThe quality of our Nation's waters: water quality in the Northern Atlantic Coastal Plain surficial aquifer system, Delaware, Maryland, New Jersey, New York, North Carolina, and Virginia, 1988-2009
The surficial aquifer system of the Northern Atlantic Coastal Plain is made up of unconfined aquifers that underlie most of the area. This aquifer system is a critical renewable source of drinking water and is the source of most flow to streams and of recharge to underlying confined aquifers. Millions of people rely on the surficial aquifer system for public and domestic water supply, in particulaAuthorsJudith M. Denver, Scott W. Ator, Jeffrey M. Fischer, Douglas C. Harned, Christopher Schubert, Zoltan SzaboComplex resistivity signatures of ethanol biodegradation in porous media
Numerous adverse effects are associated with the accidental release of ethanol (EtOH) and its persistence in the subsurface. Geophysical techniques may permit non-invasive, real time monitoring of microbial degradation of hydrocarbon. We performed complex resistivity (CR) measurements in conjunction with geochemical data analysis on three microbial-stimulated and two control columns to investigateAuthorsYves Robert Personna, Lee Slater, Dimitrios Ntarlagiannis, Dale D. Werkema, Zoltan Szabo - News
*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