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Brackish groundwater in the United States

Professional Paper 1833

Water Availability and Use Science Program
By:
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https://doi.org/10.3133/pp1833

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Abstract

For some parts of the Nation, large-scale development of groundwater has caused decreases in the amount of groundwater that is present in aquifer storage and that discharges to surface-water bodies. Water supply in some areas, particularly in arid and semiarid regions, is not adequate to meet demand, and severe drought is affecting large parts of the United States. Future water demand is projected to heighten the current stress on groundwater resources. This combination of factors has led to concerns about the availability of freshwater to meet domestic, agricultural, industrial, mining, and environmental needs. To ensure the water security of the Nation, currently [2016] untapped water sources may need to be developed.

Brackish groundwater is an unconventional water source that may offer a partial solution to current and future water demands. In support of the national census of water resources, the U.S. Geological Survey completed the national brackish groundwater assessment to better understand the occurrence and characteristics of brackish groundwater in the United States as a potential water resource. Analyses completed as part of this assessment relied on previously collected data from multiple sources; no new data were collected. Compiled data included readily available information about groundwater chemistry, horizontal and vertical extents and hydrogeologic characteristics of principal aquifers (regionally extensive aquifers or aquifer systems that have the potential to be used as a source of potable water), and groundwater use. Although these data were obtained from a wide variety of sources, the compiled data are biased toward shallow and fresh groundwater resources; data representing groundwater that is at great depths and is saline were not as readily available.

One of the most important contributions of this assessment is the creation of a database containing chemical characteristics and aquifer information for the known areas with brackish groundwater in the United States. Previously published digital data relating to brackish groundwater resources were limited to a small number of State- and regional-level studies. Data sources for this assessment ranged from single publications to large datasets and from local studies to national assessments. Geochemical data included concentrations of dissolved solids, major ions, trace elements, nutrients, and radionuclides as well as physical properties of the water (pH, temperature, and specific conductance). Additionally, the database provides selected well information (location, yield, depth, and contributing aquifer) necessary for evaluating the water resource.

The assessment was divided into national-, regional-, and aquifer-scale analyses. National-scale analyses included evaluation of the three-dimensional distribution of observed dissolved-solids concentrations in groundwater, the three-dimensional probability of brackish groundwater occurrence, and the geochemical characteristics of saline (greater than or equal to 1,000 mg/L of dissolved solids) groundwater resources. Regional-scale analyses included a summary of the percentage of observed grid cell volume in the region that was occupied by brackish groundwater within the mixture of air, water, and rock for multiple depth intervals. Aquifer-scale analyses focused primarily on four regions that contained the largest amounts of observed brackish groundwater and included a generalized description of hydrogeologic characteristics from previously published work; the distribution of dissolved-solids concentrations; considerations for developing brackish groundwater resources, including a summary of other chemical characteristics that may limit the use of brackish groundwater and the ability of sampled wells producing brackish groundwater to yield useful amounts of water; and the amount of saline groundwater being used in 2010.

Suggested Citation

Stanton, J.S., Anning, D.W., Brown, C.J., Moore, R.B., McGuire, V.L., Qi, S.L., Harris, A.C., Dennehy, K.F., McMahon, P.B., Degnan, J.R., and Böhlke, J.K., 2017, Brackish groundwater in the United States: U.S. Geological Survey Professional Paper 1833, 185 p., https://doi.org/10.3133/pp1833.

ISSN: 2330-7102 (online)

ISSN: 1044-9612 (print)

Table of Contents

  • Acknowledgments
  • Executive Summary
  • Introduction
  • Previous National- and Regional-Scale Studies
  • Data and Methods Used for Analyses
  • Brackish Groundwater in the United States
  • Regional- and Aquifer-Scale Brackish Groundwater
  • Data Gaps and Limitations
  • Next Steps for Assessing Brackish Groundwater
  • References Cited
  • Appendix 1. Estimation Results for Dissolved-Solids Regression Model
  • Appendix 2. Equations Used in Geochemical Analysis
  • Appendix 3. Relation Between Dissolved-Solids Concentration and Specific Conductance
  • Appendix 4. Estimating Brackish Groundwater Volumes for Selected Principal Aquifers With Three-Dimensional Models

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Brackish groundwater in the United States
Series title:
Professional Paper
Series number:
1833
DOI:
10.3133/pp1833
Year Published:
2017
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
New England Water Science Center
Description:
Report: xii, 185 p.; Figures: 4 Oversize, 4 Layered; Appendixes: Table, 4, 3-D Figures; Data Release; Read Me; Data Release; Project Site
Country:
United States
Online Only (Y/N):
N
Additional Online Files (Y/N):
Y