Sandra Eberts is a Professional Hydrogeologist. She holds B.S. and M.S. degrees in Geology from The Ohio State University and a Certificate in Legislative Studies from Georgetown University. Sandy has been with the USGS for more than 30 years and has experience developing and leading multidisciplinary scientific program at the regional and national level. She serves as the USGS representative to the Source Water Collaborative—27 national organizations united to protect America's sources of drinking water. She is a member of the American Water Works Association Groundwater Committee, the International Joint Commission Science Advisory Board - Research Coordination Committee and the Great Lakes Water Quality Agreement Annex 4 Objectives and Targets Task Team. Sandy is the Program Science Coordinator for the USGS Water Resources Mission Area, Office of Planning and Programming (OPP).
Science and Products
A hybrid machine learning model to predict and visualize nitrate concentration throughout the Central Valley aquifer, California, USA
Intense demand for water in the Central Valley of California and related increases in groundwater nitrate concentration threaten the sustainability of the groundwater resource. To assess contamination risk in the region, we developed a hybrid, non-linear, machine learning model within a statistical learning framework to predict nitrate...Ransom, Katherine M.; Nolan, Bernard T.; Traum, Jonathan A.; Faunt, Claudia; Bell, Andrew M.; Gronberg, Jo Ann M.; Wheeler, David C.; Zamora, Celia; Jurgens, Bryant; Schwarz, Gregory E.; Belitz, Kenneth; Eberts, Sandra; Kourakos, George; Harter, Thomas
Phosphorus (P) and HABs: Sources of P discharged from the Maumee River into Lake Erie
No abstract available.Muenich, Rebecca Logsdon; Johnson, Laura; Bratton, John F.; Fussell, Kristin DeVanna; Kane, Doug; Kalcic, Margaret; Robertson, Dale M.; Eberts, Sandra; Evans, Mary; Gibbons, Kenneth J.
Cyanobacterial harmful algal blooms and U.S. Geological Survey science capabilities
Cyanobacterial harmful algal blooms (CyanoHABs) are increasingly a global concern because CyanoHABs pose a threat to human and aquatic ecosystem health and cause economic damages. Despite advances in scientific understanding of cyanobacteria and associated compounds, many unanswered questions remain about occurrence, environmental triggers for...Graham, Jennifer L.; Dubrovsky, Neil M.; Eberts, Sandra M.
A ternary age-mixing model to explain contaminant occurrence in a deep supply well
The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively...Jurgens, Bryant; Bexfield, Laura M.; Eberts, Sandra
Educational webtool illustrating groundwater age effects on contaminant trends in wells
No abstract available.Böhlke, John Karl; Jurgens, Bryant C.; Uselmann, David J.; Eberts, Sandra M.
If groundwater is contaminated, will water from the well be contaminated?
No abstract available.Eberts, Sandra
Modeling nitrate at domestic and public-supply well depths in the Central Valley, California
Aquifer vulnerability models were developed to map groundwater nitrate concentration at domestic and public-supply well depths in the Central Valley, California. We compared three modeling methods for ability to predict nitrate concentration >4 mg/L: logistic regression (LR), random forest classification (RFC), and random forest regression (RFR...Nolan, Bernard T.; Gronberg, JoAnn M.; Faunt, Claudia C.; Eberts, Sandra M.; Belitz, Ken
The quality of our Nation's waters: factors affecting public-supply-well vulnerability to contamination: understanding observed water quality and anticipating future water quality
As part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program, a study was conducted from 2001 to 2011 to shed light on factors that affect the vulnerability of water from public-supply wells to contamination (referred to hereafter as “public-supply-well vulnerability”). The study was designed as a follow-up to earlier...Eberts, Sandra M.; Thomas, Mary Ann; Jagucki, Martha L.
Assessing the vulnerability of public-supply wells to contamination: Rio Grande aquifer system in Albuquerque, New Mexico
This fact sheet highlights findings from the vulnerability study of a public-supply well in Albuquerque, New Mexico (hereafter referred to as “the study well”). The study well produces about 3,000 gallons of water per minute from the Rio Grande aquifer system. Water samples were collected at the study well, at two other nearby public-supply wells...Jagucki, Martha L.; Bexfield, Laura M.; Heywood, Charles E.; Eberts, Sandra M.
TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data
TracerLPM is an interactive Excel® (2007 or later) workbook program for evaluating groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). Lumped parameter models are mathematical models of transport based on simplified aquifer geometry and flow configurations that account for effects of...Jurgens, Bryant C.; Böhlke, J.K.; Eberts, Sandra M.
Assessing the vulnerability of public-supply wells to contamination—Edwards aquifer near San Antonio, Texas
This fact sheet highlights findings from the vulnerability study of a public-supply well field in San Antonio, Texas. The well field consists of six production wells that tap the Edwards aquifer. Typically, one or two wells are pumped at a time, yielding an average total of 20-21 million gallons per day. Water samples were collected from public-...Jagucki, Martha L.; Musgrove, MaryLynn; Lindgren, Richard J.; Fahlquist, Lynne; Eberts, Sandra M.
Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells
Wells screened across multiple aquifers can provide pathways for the movement of surprisingly large volumes of groundwater to confined aquifers used for public water supply (PWS). Using a simple numerical model, we examine the impact of several pumping scenarios on leakage from an unconfined aquifer to a confined aquifer and conclude that a single...Johnson, R.L.; Clark, B.R.; Landon, M.K.; Kauffman, L.J.; Eberts, S.M.
The USGS Groundwater Age Mixtures and Contaminant Trends Tool (GAMACTT) can be used to explore the effects of basic aquifer properties and well configurations on groundwater age mixtures in groundwater discharge and on contaminant trends from varying nonpoint-source contaminant input scenarios.