About the USGS National Brackish Groundwater Assessment
Completed
By Water Resources Mission Area
July 22, 2021
The objectives of the National Brackish Groundwater Assessment were to identify and characterize aquifers that contain brackish groundwater in the United States. For purposes of this study, brackish groundwater is defined as having dissolved solids at concentrations between 1,000 and 10,000 milligrams per liter.
Sources/Usage: Public Domain. View Media Details
This study provided information about brackish-groundwater resources at national and regional scales and was not for defining site-specific or localized conditions. Study results can be used to identify areas where further evaluation of aquifers containing brackish groundwater will be most productive for potential users of the resource.
Major components of the study included:
- Compiling existing information to assess brackish aquifers
- Describing, to the extent that available data permit, dissolved-solids concentrations, other chemical characteristics, horizontal and vertical extents of aquifers containing brackish groundwater, ability of the aquifers to yield water, and current brackish groundwater use
- Generating national maps of dissolved-solids concentrations
- Identifying data gaps that limit full characterization of brackish aquifers
The study provided the following improvements upon previous work:
- An updated national inventory of brackish groundwater: Previous national assessments of the distribution of brackish groundwater used only a limited amount of the dissolved-solids data that currently are available. A more complete set of information was assembled from a wide variety of sources and included more recently collected data.
- Publication of digital dataset: The national geochemical database from the assessment was released as a digital dataset so that other scientists can conduct assessments tailored to their specific needs. Published digital data relating to brackish groundwater previously were limited to a small number of State and regional studies.
- Enhanced characterization: The updated dissolved-solids inventory was used to characterize brackish aquifers at a higher spatial resolution than previous national work. In addition to dissolved-solids distribution, other chemical characteristics (such as major-ion concentrations) and hydrogeologic characteristics (such as aquifer material, depth, and hydraulic properties) were assessed to determine brackish groundwater availability. Improved characterization is important for understanding and predicting occurrences in areas with few data, and also for assessing limitations imposed by different uses and (or) treatment options.
- Consistent approach: Although several detailed assessments of brackish aquifers had been conducted at State and regional scales prior to this assessment, the methods differed among the studies. This work described brackish aquifers using consistent data analysis and assessment methods across the country.
Below are other science projects associated with the National Brackish Groundwater Assessment.
Brackish Groundwater Assessment
All water naturally contains dissolved solids that, if present in sufficient concentration, can make a water resource "brackish", or distastefully salty. The amount of fresh or potable groundwater in storage has declined for many areas in the U.S., leading to concerns about the future availability of water. Using brackish groundwater could supplement or, in some places, replace the use of...
National Brackish Groundwater Assessment: Sources of Dissolved Solids in Brackish Groundwater
A variety of conditions and mechanisms can cause groundwater to become brackish. An understanding of the sources of dissolved solids that contribute to the formation of brackish groundwater can help determine where brackish aquifers are likely to exist and can provide clues about other characteristics, such as the chemical composition, of brackish aquifers.
National Brackish Groundwater Assessment: How is Brackish Groundwater Being Used?
Industry and public drinking-water suppliers are increasingly turning to brackish groundwater to supplement or replace the use of freshwater. Brackish groundwater is either directly used or treated.
National Brackish Groundwater Assessment: Pilot Saline Studies
Three pilot studies were conducted (2010-2012) to assess saline groundwater resources at regional scales. The goals of the pilot studies were to determine the availability of data for assessing the distribution and character of saline groundwater and test and develop methodologies for assessing the resource.
National Brackish Groundwater Assessment: Previous Work
Interest in the distribution and classification of brackish groundwater for use as a source of water supply has been longstanding. These studies provided valuable background for the National Brackish Groundwater Assessment.
The objectives of the National Brackish Groundwater Assessment were to identify and characterize aquifers that contain brackish groundwater in the United States. For purposes of this study, brackish groundwater is defined as having dissolved solids at concentrations between 1,000 and 10,000 milligrams per liter.
Sources/Usage: Public Domain. View Media Details
This study provided information about brackish-groundwater resources at national and regional scales and was not for defining site-specific or localized conditions. Study results can be used to identify areas where further evaluation of aquifers containing brackish groundwater will be most productive for potential users of the resource.
Major components of the study included:
- Compiling existing information to assess brackish aquifers
- Describing, to the extent that available data permit, dissolved-solids concentrations, other chemical characteristics, horizontal and vertical extents of aquifers containing brackish groundwater, ability of the aquifers to yield water, and current brackish groundwater use
- Generating national maps of dissolved-solids concentrations
- Identifying data gaps that limit full characterization of brackish aquifers
The study provided the following improvements upon previous work:
- An updated national inventory of brackish groundwater: Previous national assessments of the distribution of brackish groundwater used only a limited amount of the dissolved-solids data that currently are available. A more complete set of information was assembled from a wide variety of sources and included more recently collected data.
- Publication of digital dataset: The national geochemical database from the assessment was released as a digital dataset so that other scientists can conduct assessments tailored to their specific needs. Published digital data relating to brackish groundwater previously were limited to a small number of State and regional studies.
- Enhanced characterization: The updated dissolved-solids inventory was used to characterize brackish aquifers at a higher spatial resolution than previous national work. In addition to dissolved-solids distribution, other chemical characteristics (such as major-ion concentrations) and hydrogeologic characteristics (such as aquifer material, depth, and hydraulic properties) were assessed to determine brackish groundwater availability. Improved characterization is important for understanding and predicting occurrences in areas with few data, and also for assessing limitations imposed by different uses and (or) treatment options.
- Consistent approach: Although several detailed assessments of brackish aquifers had been conducted at State and regional scales prior to this assessment, the methods differed among the studies. This work described brackish aquifers using consistent data analysis and assessment methods across the country.
Below are other science projects associated with the National Brackish Groundwater Assessment.
Brackish Groundwater Assessment
All water naturally contains dissolved solids that, if present in sufficient concentration, can make a water resource "brackish", or distastefully salty. The amount of fresh or potable groundwater in storage has declined for many areas in the U.S., leading to concerns about the future availability of water. Using brackish groundwater could supplement or, in some places, replace the use of...
National Brackish Groundwater Assessment: Sources of Dissolved Solids in Brackish Groundwater
A variety of conditions and mechanisms can cause groundwater to become brackish. An understanding of the sources of dissolved solids that contribute to the formation of brackish groundwater can help determine where brackish aquifers are likely to exist and can provide clues about other characteristics, such as the chemical composition, of brackish aquifers.
National Brackish Groundwater Assessment: How is Brackish Groundwater Being Used?
Industry and public drinking-water suppliers are increasingly turning to brackish groundwater to supplement or replace the use of freshwater. Brackish groundwater is either directly used or treated.
National Brackish Groundwater Assessment: Pilot Saline Studies
Three pilot studies were conducted (2010-2012) to assess saline groundwater resources at regional scales. The goals of the pilot studies were to determine the availability of data for assessing the distribution and character of saline groundwater and test and develop methodologies for assessing the resource.
National Brackish Groundwater Assessment: Previous Work
Interest in the distribution and classification of brackish groundwater for use as a source of water supply has been longstanding. These studies provided valuable background for the National Brackish Groundwater Assessment.