Skip to main content
U.S. flag

An official website of the United States government

Zeno Levy, Ph.D.

I am a hydrogeologist and geochemist at the California Water Science Center specializing in drinking water resources and groundwater-surface water interactions.

I work primarily on the California State Water Resources Control Board's Groundwater Ambient Monitoring and Assessment (GAMA) program. I am interested in understanding how climate-driven groundwater recharge and discharge processes impact the hydrology and geochemistry of wetlands and drinking water resources. I specialize in low-temperature, aqueous geochemistry and utilize a wide variety of naturally occurring hydrologic tracers, including: major ions, trace halogens, stable isotopes of water, and dissolved noble gases. I couple these tracer suites with physical hydrology, geochemical modeling (equilibrium and reactive transport), and geoelectrical methods to better understand porefluid evolution and transport in space and time. While my work fundamentally engages a process-based understanding of pore- to landform-scale water system functions, I am interested in identifying specific processes with landscape-scale transfer value that can help to forecast the fate of wetlands and drinking water resources to changes in climate.

Science and Products

link
Map of Hydrogeologic provinces of California and distribution of wells

Groundwater Ambient Monitoring & Assessment (GAMA)

The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the quality of...
By
California Water Science Center
link

Groundwater Ambient Monitoring & Assessment (GAMA)

The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the quality of...
Learn More

Grid Cells and Modeled Groundwater Levels to Characterize Hydrologic Conditions for Public-supply Aquifers in California's Central Valley, 1990-2020

This data release documents grid cells and modeled groundwater levels for hydrologic characterization of aquifer areas used for public drinking-water supply in California’s Central Valley from 1990 to 2020. Observations of spring groundwater level (median depth to groundwater measured from January through April) were calculated for selected wells from the California Department of Water Resources (
By
California Water Science Center

Potential Explanatory Factors for Groundwater Quality in the Northern Sierra Nevada Foothills Domestic-Aquifer Assessment Study Units, 2015-2017: California GAMA Priority Basin Project

This data release codifies and attributes explanatory factors that could potentially impact groundwater quality at 142 groundwater sites (wells or developed springs) used for domestic water supply and 310 groundwater sites used for public water supply in the northern Sierra Nevada foothills. Water quality from domestic groundwater sites was assessed as part of the California State Water Resources
By
California Water Science Center

Dissolved Noble Gas Concentrations and Modeled Recharge Temperatures for Groundwater from Northern Sierra Nevada Foothills Shallow Aquifer Assessment Study Units, 2015-2017: Results from the California GAMA Priority Basin Project

This data release documents 155 sets of dissolved noble gas analyses (neon, argon, krypton, xenon) and 153 modeled recharge temperatures for groundwater sampled from domestic water supply wells and springs throughout the northern Sierra Nevada foothills as part of the California State Water Resources Control Board's Groundwater Ambient Monitoring and Assessment (GAMA) Program in 2015-2017. Data fr
By
California Water Science Center

Quality of groundwater used for domestic drinking-water supply in the Coachella Valley, 2020

Groundwater is the primary source of drinking water in the Coachella Valley in the desert region of southern California. Although most people in Coachella Valley are served by public drinking-water systems, about 20,000 people rely on private domestic or small-system wells (referred to herein as domestic wells). Recently, the U.S. Geological Survey (USGS) found that 39 percent of the groundwater r
Authors
Andrew L. Soldavini, Jennifer S. Harkness, Zeno F. Levy, Miranda S. Fram
By
Water Resources Mission Area, California Water Science Center

Quality of groundwater used for domestic supply in the Modesto, Turlock, and Merced Subbasins of the San Joaquin Valley, California

Summary More than 2 million Californians rely on groundwater from privately owned domestic wells for drinking-water supply. This report summarizes a water-quality survey of domestic and small-system drinking-water supply wells in the Modesto, Turlock, and Merced subbasins of the San Joaquin Valley where more than 78,000 residents are estimated to use privately owned domestic wells. Results indicat
Authors
Zeno F. Levy, Mariia Balkan, Jennifer L. Shelton
By
Water Resources Mission Area, California Water Science Center

Modeling the dynamic penetration depth of post-1950s water in unconfined aquifers using environmental tracers: Central Valley, California

The penetration depth of post-1950s recharge (D-1950) in aquifers is a marker that is frequently used to identify groundwater that is susceptible to anthropogenic contamination. Here, we compute D-1950 values at wells, interpolate them in space, and project them across time to map the moving front of modern recharge in four dimensions in the Central Valley aquifer system, California, USA. Tracers
Authors
Kirsten Faulkner, Bryant Jurgens, Stefan Voss, Danielle Dupuy, Zeno Levy
By
Water Resources Mission Area, California Water Science Center

Lessons learned from wetlands research at the Cottonwood Lake Study Area, Stutsman County, North Dakota, 1967–2021

Depressional wetlands in the Prairie Pothole Region of North America have a long history of investigation owing to their importance in maintaining migratory-bird populations, especially waterfowl. One area of particularly intensive study is the Cottonwood Lake study area in Stutsman County, North Dakota. Studies at the Cottonwood Lake study area began in 1967 and continue through the present (2022
Authors
David M. Mushet, Ned H. Euliss, Donald O. Rosenberry, James W. LaBaugh, Sheel Bansal, Zeno F. Levy, Owen P. McKenna, Kyle I. McLean, Christopher T. Mills, Brian P. Neff, Richard D. Nelson, Matthew J. Solensky, Brian Tangen
By
Ecosystems Mission Area, Northern Prairie Wildlife Research Center

Critical aquifer overdraft accelerates degradation of groundwater quality in California’s Central Valley during drought

Drought-induced pumpage has precipitated dramatic groundwater-level declines in California’s Central Valley over the past 30 years, but the impacts of aquifer overdraft on water quality are poorly understood. This study coupled over 160,000 measurements of nitrate from ∼6,000 public-supply wells with a 30-year reconstruction of groundwater levels throughout the Central Valley to evaluate dynamic r
Authors
Zeno Levy, Bryant Jurgens, Karen R. Burow, Stefan Voss, Kirsten Faulkner, Jose Alfredo Arroyo-Lopez, Miranda S. Fram
By
Water Resources Mission Area, California Water Science Center

Quality of groundwater used for domestic supply in the northern San Joaquin Valley, California

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project (PBP) of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and provides increased public access to groundwater-quality information.
Authors
Zeno F. Levy, Mariia Balkan, Jennifer L. Shelton
By
Water Resources Mission Area, California Water Science Center

Status and understanding of groundwater quality in the northern Sierra Nevada foothills domestic-supply aquifer study units, 2015–17—California GAMA Priority Basin Project

Groundwater quality in the northern Sierra Nevada foothills region of California was investigated as part of California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring Assessment Priority Basin Project (GAMA-PBP). The region was divided into two study units: the Yuba-Bear watersheds (YBW) study unit and the American-Cosumnes-Mokelumne watersheds (ACMW) study unit. The GA
Authors
Zeno F. Levy, Miranda S. Fram
By
Water Resources Mission Area, California Water Science Center

Geologic influences on the quality of groundwater used for domestic supply in the northern Sierra Nevada Foothills

Approximately 2 million California residents depend on groundwater from domestic wells for their drinking-water supply. The State of California, in collaboration with the U.S. Geological Survey, created the Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) to assess the quality of groundwater used for domestic supply throughout the state and determine regional
Authors
Zeno F. Levy, Miranda S. Fram
By
Water Resources Mission Area, California Water Science Center

Effects of surface-water use on domestic groundwater availability and quality during drought in the Sierra Nevada foothills, California

BackgroundApproximately 2 million California residents rely on privately owned domestic wells for drinking water. During the California drought of 2012−16 groundwater levels declined in many parts of the state and wells were deepened in response. Most of the wells deepened during this time were domestic wells that were drilled into fractured bedrock throughout the Sierra Nevada foothills region of
Authors
Zeno F. Levy, Miranda S. Fram, Kimberly A. Taylor
By
Water Resources Mission Area, California Water Science Center

Effects of montane watershed development on vulnerability of domestic groundwater supply during drought

Climate change is expected to reduce recharge to montane aquifers in the western United States, but it is unclear how this will impact groundwater resources in watersheds where intensive surface-water development has disrupted the natural hydrologic regime. To better understand sources of recharge and associated vulnerabilities of groundwater supply in this setting, we made a detailed geochemical
Authors
Zeno Levy, Miranda S. Fram, Kirsten Faulkner, Charles N. Alpers, Evelyn M Soltero, Kimberly A. Taylor
By
Water Resources Mission Area, California Water Science Center

Non-USGS Publications**

Levy ZF, Rosenberry DO, Moucha R, Mushet DM, Goldhaber MB, LaBaugh JW, Fiorentino AJ, Siegel DI. 2018. Drought-induced recharge promotes long-term storage of porewater salinity beneath a prairie wetland. Journal of Hydrology 557: 391-406, https://doi.org/10.1016/j.jhydrol.2017.12.005.
Levy ZF, Mills CT, Lu Z, Goldhaber MB, Rosenberry DO, Mushet DM, Lautz LK, Zhou X, Siegel DI. 2018. Using halogens (Cl, Br, I) to understand the hydrogeochemical evolution of drought-derived saline porewater beneath a prairie wetland. Chemical Geology 476: 191-207, https://doi.org/10.1016/j.chemgeo.2017.11.017.
Levy ZF, Siegel DI, Glaser PH, Samson SD, Dasgupta SS. 2016. Peat porewaters have contrasting geochemical fingerprints for groundwater recharge and discharge due to matrix diffusion in a large, northern bog-fen complex. Journal of Hydrology 541: 941-951, https://dx.doi.org/10.1016/j.jhydrol.2016.08.001.
Levy ZF, Smardon RC, Bays JS, Meyer D. 2014. A Point Source of a Different Color: Identifying a Gap in United States Regulatory Policy for “Green” CSO Treatment Using Constructed Wetlands. Sustainability 6(5): 2392-2412, https://dx.doi.org/10.3390/su6052392.
Levy ZF, Siegel DI, Dasgupta SS, Glaser PH, Welker JM. 2014. Stable isotopes of water show deep seasonal recharge in northern bogs and fens. Hydrological Processes 228: 4938-4952, https://dx.doi.org/10.1002/hyp.9983.

**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.

link

Increased Pumping in California’s Central Valley During Drought Worsens Groundwater Quality

SACRAMENTO, Calif. – Intensive pumping of aquifers during drought can speed up deterioration of groundwater quality, according to a new study by the U...

Read Article

Science and Products