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How important is groundwater?

Groundwater, which is in aquifers below the surface of the Earth, is one of the Nation's most important natural resources. Groundwater is the source of about 37 percent of the water that county and city water departments supply to households and businesses (public supply). It provides drinking water for more than 90 percent of the rural population who do not get their water delivered to them from a county/city water department or private water company.

Even some major cities, such as San Antonio, Texas, rely solely on groundwater for all their needs. About 42 percent of the water used for irrigation comes from groundwater.

Withdrawals of groundwater are expected to rise as the population increases and available sites for surface reservoirs become more limited.

Learn more: Groundwater Use

Related Content

link
Glass of water

If the ground filters water, is groundwater always clean?

Water drawn from a well was once precipitation that fell onto Earth's surface. It seeped into the ground and, over time, occupied the porous space in some subsurface material. Big particles that are in surface streams, such as leaf chunks, will not be seen in groundwater. So, yes, big particles are filtered out by the ground, along with some minerals and chemicals that are too small to see.But...

link

If the ground filters water, is groundwater always clean?

Water drawn from a well was once precipitation that fell onto Earth's surface. It seeped into the ground and, over time, occupied the porous space in some subsurface material. Big particles that are in surface streams, such as leaf chunks, will not be seen in groundwater. So, yes, big particles are filtered out by the ground, along with some minerals and chemicals that are too small to see.But...

Learn More
link
a graph of Groundwater flow patterns and the freshwater-saltwater transition zone in an idealized coastal aquifer

What is groundwater?

Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table.Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...

link

What is groundwater?

Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table.Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...

Learn More
link
Image: Scientist Taking Water Samples

Where can I find detailed sampling methods for surface water and groundwater?

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for USGS personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. The manual is published as separate chapters.Learn more: Techniques of Water-Resources Investigations Reports

link

Where can I find detailed sampling methods for surface water and groundwater?

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for USGS personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. The manual is published as separate chapters.Learn more: Techniques of Water-Resources Investigations Reports

Learn More
link
Photo of USGS staffer collecting groundwater sample

How frequently are volatile organic compounds (VOCs) detected in groundwater?

Volatile organic compounds (VOCs), which are widely used in the manufacture of many products including refrigerants, plastics, adhesives, paints, and petroleum products, have been detected in about one-third of the wells sampled by the National Water-Quality Assessment (NAWQA) Program of the USGS. Chloroform and other trihalomethanes, the most commonly detected compounds, were found in about 9...

link

How frequently are volatile organic compounds (VOCs) detected in groundwater?

Volatile organic compounds (VOCs), which are widely used in the manufacture of many products including refrigerants, plastics, adhesives, paints, and petroleum products, have been detected in about one-third of the wells sampled by the National Water-Quality Assessment (NAWQA) Program of the USGS. Chloroform and other trihalomethanes, the most commonly detected compounds, were found in about 9...

Learn More
link
USGS scientist collecting water samples on a wastewater disposal facility

Can hydraulic fracturing impact the quality of groundwater or surface water?

Conducted properly, hydraulic fracturing (or “fracking”) has little possibility of contaminating water supplies. Properly constructed wells prevent drilling fluids, hydraulic fracturing fluids, deep saline formation waters, or oil and gas from entering aquifers. Carefully constructed and operated well sites have the ability to contain potential spills and minimize runoff into surface waters.As...

link

Can hydraulic fracturing impact the quality of groundwater or surface water?

Conducted properly, hydraulic fracturing (or “fracking”) has little possibility of contaminating water supplies. Properly constructed wells prevent drilling fluids, hydraulic fracturing fluids, deep saline formation waters, or oil and gas from entering aquifers. Carefully constructed and operated well sites have the ability to contain potential spills and minimize runoff into surface waters.As...

Learn More
link
Girls getting a glass of water at a well pump at The Tollgate House, Meridian Historical Village, Okemos, MI

Where can I get my well water tested?

Contact your county or state health department or check with your State Certification Officer for a list of state certified laboratories in your area that do water testing. The cost will vary, depending on the laboratory and the test(s), but people usually consider the cost to be reasonable.Also try using your browser's search engine to do a search on "well owner resources".

link

Where can I get my well water tested?

Contact your county or state health department or check with your State Certification Officer for a list of state certified laboratories in your area that do water testing. The cost will vary, depending on the laboratory and the test(s), but people usually consider the cost to be reasonable.Also try using your browser's search engine to do a search on "well owner resources".

Learn More
link
contour maps of water-table surface of Long Island

How can I find the depth to the water table in a specific location?

The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface infiltrates into the ground and the water table rises. When water-loving plants start to grow again in the spring and precipitation gives way to hot, dry summers, the water table falls...

link

How can I find the depth to the water table in a specific location?

The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface infiltrates into the ground and the water table rises. When water-loving plants start to grow again in the spring and precipitation gives way to hot, dry summers, the water table falls...

Learn More
link
Aquifers: Map of the Principal Aquifers of the United States

What is the Ground Water Atlas of the United States?

This Ground Water Atlas of the United States is a series of USGS publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers of the Nation. The series consists of 13 chapters that describe the regional groundwater resources that collectively cover 50 States, Puerto Rico, and the U.S. Virgin Islands.Learn more:Aquifers: Map of the...

link

What is the Ground Water Atlas of the United States?

This Ground Water Atlas of the United States is a series of USGS publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers of the Nation. The series consists of 13 chapters that describe the regional groundwater resources that collectively cover 50 States, Puerto Rico, and the U.S. Virgin Islands.Learn more:Aquifers: Map of the...

Learn More
link
All water on Earth in a sphere, placed over a "dry" globe

How much natural water is there?

Earth is estimated to hold about 1,460,000,000 cubic kilometers of water. The breakdown of where all that water resides is estimated as follows:Oceans (saline) 1,419,120,000 cubic kilometersIce caps and glaciers (fresh) 31,244,000 cubic kilometersGroundwater (fresh and saline) 8,906,000 cubic kilometersStreams and lakes (fresh) 132,860 cubic kilometersLakes (saline) 116,800 cubic kilometersOther-...

link

How much natural water is there?

Earth is estimated to hold about 1,460,000,000 cubic kilometers of water. The breakdown of where all that water resides is estimated as follows:Oceans (saline) 1,419,120,000 cubic kilometersIce caps and glaciers (fresh) 31,244,000 cubic kilometersGroundwater (fresh and saline) 8,906,000 cubic kilometersStreams and lakes (fresh) 132,860 cubic kilometersLakes (saline) 116,800 cubic kilometersOther-...

Learn More
link
Domestic water use, 2010, by State

How much water is used by people in the United States?

Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories. That data is revised every 5 years.As of 2015, the United States uses 322 billion gallons of water per day (Bgal/day). The three largest water-use categories were irrigation (118 Bgal/day), thermoelectric power (133 Bgal/day), and public supply (39 Bgal/day), cumulatively accounting for 90...

link

How much water is used by people in the United States?

Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories. That data is revised every 5 years.As of 2015, the United States uses 322 billion gallons of water per day (Bgal/day). The three largest water-use categories were irrigation (118 Bgal/day), thermoelectric power (133 Bgal/day), and public supply (39 Bgal/day), cumulatively accounting for 90...

Learn More
link
USGS scientist standing with a pole annotated with land-surface elevation marks at given years at bench mark W 990.
link
USGS scientist standing with a pole annotated with land-surface elevation marks at given years at bench mark H 1235 RESET.
link
Plants in a field
link
link
link
USGS employee sampling an urban groundwater well
link
Irrigation water from a groundwater well on a rice crop field
link
Irrigation groundwater well
link
Water well windmill
link
Groundwater emerging from a cliff
link
Illustration of conceptual model of groundwater flow and occurrence.
link
Diagram model of a water flow system showing groundwater flow
link

Estimated groundwater withdrawals from principal aquifers in the United States, 2015

In 2015, about 84,600 million gallons per day (Mgal/d) of groundwater were withdrawn in the United States for various uses including public supply, self-supplied domestic, industrial, mining, thermoelectric power, aquaculture, livestock, and irrigation. Of this total, about 94 percent (79,200 Mgal/d) was withdrawn from principal aquifers, which are defined as regionally extensive aquifers or aquif
By
Lower Mississippi-Gulf Water Science Center

Water priorities for the nation—The U.S. Geological Survey next generation water observing system

The challenges of providing safe and sustainable water supplies for human and ecological uses and protecting lives and property during water emergencies are well recognized. The U.S. Geological Survey (USGS) plays an essential role in meeting these challenges through its observational networks and renowned water science and research activities (National Academies of Science, Engineering, and Medic

Estimated use of water in the United States in 2015

Water use in the United States in 2015 was estimated to be about 322 billion gallons per day (Bgal/d), which was 9 percent less than in 2010. The 2015 estimates put total withdrawals at the lowest level since before 1970, following the same overall trend of decreasing total withdrawals observed from 2005 to 2010. Freshwater withdrawals were 281 Bgal/d, or 87 percent of total withdrawals, and salin
By
Water Resources, Water Availability and Use Science Program, Maryland-Delaware-D.C. Water Science Center

The quality of our Nation's waters: Water quality in principal aquifers of the United States, 1991-2010

About 130 million people in the United States rely on groundwater for drinking water, and the need for high-quality drinking-water supplies becomes more urgent as our population grows. Although groundwater is a safe, reliable source of drinking water for millions of people nationwide, high concentrations of some chemical constituents can pose potential human-health concerns. Some of these contamin
By
Water Resources, Colorado Water Science Center

Summary of estimated water use in the United States in 2010

About 355,000 million gallons per day (Mgal/d) of water was withdrawn for use in the United States during 2010, a decline of 13 percent from 2005 and a substantial change from the level of about 400,000 Mgal/d reported from 1985 to 2005. Withdrawals for 2010 were lower than withdrawals estimated for 1970. Fresh surface-water withdrawals (230,000 Mgal/d) were almost 15 percent less than in 2005, an
By
Water Resources, Water Availability and Use Science Program, South Atlantic Water Science Center (SAWSC)

Groundwater studies: principal aquifer surveys

In 1991, the U.S. Congress established the National Water-Quality Assessment (NAWQA) program within the U.S. Geological Survey (USGS) to develop nationally consistent long-term datasets and provide information about the quality of the Nation’s streams and groundwater. The USGS uses objective and reliable data, water-quality models, and systematic scientific studies to assess current water-quality
By
Water Resources, California Water Science Center

What is ground water?

By
Water Resources

Sustainability of ground-water resources

The pumpage of fresh ground water in the United States in 1995 was estimated to be approximately 77 billion gallons per day (Solley and others, 1998), which is about 8 percent of the estimated 1 trillion gallons per day of natural recharge to the Nation's ground-water systems (Nace, 1960). From an overall national perspective, the ground-water resource appears ample. Locally, however, the availabi
By
Water Resources

Ground water and surface water: A single resource

The importance of considering ground water and surface water as a single resource has become increasingly evident. Issues related to water supply, water quality, and degradation of aquatic environments are reported on frequently. The interaction of ground water and surface water has been shown to be a significant concern in many of these issues. Contaminated aquifers that discharge to streams can
By
Water Resources, Ecosystems, Toxic Substances Hydrology, Environmental Health Program, Dakota Water Science Center

Ground water and the rural homeowner

As the salesmen sang in the musical The Music Man, "You gotta know the territory." This saying is also true when planning to buy or build a house. Learn as much as possible about the land, the water supply, and the septic system of the house before buying or building. Do not just look at the construction aspects or the beauty of the home and surroundings. Be sure to consider the environmental cond
By
Water Resources
link

Study Estimates about 2.1 Million People using Wells High in Arsenic

Most Arsenic Presumed to be From Naturally Occurring Sources

Read Article
link

How Well Do You Know Groundwater

Groundwater, which flows out of sight through aquifers beneath our feet, is one of the Nation’s most important natural resources. In recognition of Na...

Read Article
link

How Much Water Do We Use?

The USGS National Water-Use Science project has documented 60 years of water-use from 1950 to 2010 in an interactive map.  Choose a year and pick a...

Read Article
link

Helping Desert Communities Find Hidden Water

Desert communities throughout the Southwest are putting water availability at the top of their municipal agendas.

Read Article
link

Large Precipitation Events are Critical in Replenishing Groundwater Resources

Large precipitation events that occur about every 10 years are a critical source of recharge for replenishing groundwater resources, according to a ne...

Read Article

Related Content

  • FAQ
    link
    Glass of water

    If the ground filters water, is groundwater always clean?

    Water drawn from a well was once precipitation that fell onto Earth's surface. It seeped into the ground and, over time, occupied the porous space in some subsurface material. Big particles that are in surface streams, such as leaf chunks, will not be seen in groundwater. So, yes, big particles are filtered out by the ground, along with some minerals and chemicals that are too small to see.But...

    link

    If the ground filters water, is groundwater always clean?

    Water drawn from a well was once precipitation that fell onto Earth's surface. It seeped into the ground and, over time, occupied the porous space in some subsurface material. Big particles that are in surface streams, such as leaf chunks, will not be seen in groundwater. So, yes, big particles are filtered out by the ground, along with some minerals and chemicals that are too small to see.But...

    Learn More
    link
    a graph of Groundwater flow patterns and the freshwater-saltwater transition zone in an idealized coastal aquifer

    What is groundwater?

    Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table.Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...

    link

    What is groundwater?

    Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table.Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...

    Learn More
    link
    Image: Scientist Taking Water Samples

    Where can I find detailed sampling methods for surface water and groundwater?

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for USGS personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. The manual is published as separate chapters.Learn more: Techniques of Water-Resources Investigations Reports

    link

    Where can I find detailed sampling methods for surface water and groundwater?

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for USGS personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. The manual is published as separate chapters.Learn more: Techniques of Water-Resources Investigations Reports

    Learn More
    link
    Photo of USGS staffer collecting groundwater sample

    How frequently are volatile organic compounds (VOCs) detected in groundwater?

    Volatile organic compounds (VOCs), which are widely used in the manufacture of many products including refrigerants, plastics, adhesives, paints, and petroleum products, have been detected in about one-third of the wells sampled by the National Water-Quality Assessment (NAWQA) Program of the USGS. Chloroform and other trihalomethanes, the most commonly detected compounds, were found in about 9...

    link

    How frequently are volatile organic compounds (VOCs) detected in groundwater?

    Volatile organic compounds (VOCs), which are widely used in the manufacture of many products including refrigerants, plastics, adhesives, paints, and petroleum products, have been detected in about one-third of the wells sampled by the National Water-Quality Assessment (NAWQA) Program of the USGS. Chloroform and other trihalomethanes, the most commonly detected compounds, were found in about 9...

    Learn More
    link
    USGS scientist collecting water samples on a wastewater disposal facility

    Can hydraulic fracturing impact the quality of groundwater or surface water?

    Conducted properly, hydraulic fracturing (or “fracking”) has little possibility of contaminating water supplies. Properly constructed wells prevent drilling fluids, hydraulic fracturing fluids, deep saline formation waters, or oil and gas from entering aquifers. Carefully constructed and operated well sites have the ability to contain potential spills and minimize runoff into surface waters.As...

    link

    Can hydraulic fracturing impact the quality of groundwater or surface water?

    Conducted properly, hydraulic fracturing (or “fracking”) has little possibility of contaminating water supplies. Properly constructed wells prevent drilling fluids, hydraulic fracturing fluids, deep saline formation waters, or oil and gas from entering aquifers. Carefully constructed and operated well sites have the ability to contain potential spills and minimize runoff into surface waters.As...

    Learn More
    link
    Girls getting a glass of water at a well pump at The Tollgate House, Meridian Historical Village, Okemos, MI

    Where can I get my well water tested?

    Contact your county or state health department or check with your State Certification Officer for a list of state certified laboratories in your area that do water testing. The cost will vary, depending on the laboratory and the test(s), but people usually consider the cost to be reasonable.Also try using your browser's search engine to do a search on "well owner resources".

    link

    Where can I get my well water tested?

    Contact your county or state health department or check with your State Certification Officer for a list of state certified laboratories in your area that do water testing. The cost will vary, depending on the laboratory and the test(s), but people usually consider the cost to be reasonable.Also try using your browser's search engine to do a search on "well owner resources".

    Learn More
    link
    contour maps of water-table surface of Long Island

    How can I find the depth to the water table in a specific location?

    The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface infiltrates into the ground and the water table rises. When water-loving plants start to grow again in the spring and precipitation gives way to hot, dry summers, the water table falls...

    link

    How can I find the depth to the water table in a specific location?

    The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface infiltrates into the ground and the water table rises. When water-loving plants start to grow again in the spring and precipitation gives way to hot, dry summers, the water table falls...

    Learn More
    link
    Aquifers: Map of the Principal Aquifers of the United States

    What is the Ground Water Atlas of the United States?

    This Ground Water Atlas of the United States is a series of USGS publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers of the Nation. The series consists of 13 chapters that describe the regional groundwater resources that collectively cover 50 States, Puerto Rico, and the U.S. Virgin Islands.Learn more:Aquifers: Map of the...

    link

    What is the Ground Water Atlas of the United States?

    This Ground Water Atlas of the United States is a series of USGS publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers of the Nation. The series consists of 13 chapters that describe the regional groundwater resources that collectively cover 50 States, Puerto Rico, and the U.S. Virgin Islands.Learn more:Aquifers: Map of the...

    Learn More
    link
    All water on Earth in a sphere, placed over a "dry" globe

    How much natural water is there?

    Earth is estimated to hold about 1,460,000,000 cubic kilometers of water. The breakdown of where all that water resides is estimated as follows:Oceans (saline) 1,419,120,000 cubic kilometersIce caps and glaciers (fresh) 31,244,000 cubic kilometersGroundwater (fresh and saline) 8,906,000 cubic kilometersStreams and lakes (fresh) 132,860 cubic kilometersLakes (saline) 116,800 cubic kilometersOther-...

    link

    How much natural water is there?

    Earth is estimated to hold about 1,460,000,000 cubic kilometers of water. The breakdown of where all that water resides is estimated as follows:Oceans (saline) 1,419,120,000 cubic kilometersIce caps and glaciers (fresh) 31,244,000 cubic kilometersGroundwater (fresh and saline) 8,906,000 cubic kilometersStreams and lakes (fresh) 132,860 cubic kilometersLakes (saline) 116,800 cubic kilometersOther-...

    Learn More
    link
    Domestic water use, 2010, by State

    How much water is used by people in the United States?

    Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories. That data is revised every 5 years.As of 2015, the United States uses 322 billion gallons of water per day (Bgal/day). The three largest water-use categories were irrigation (118 Bgal/day), thermoelectric power (133 Bgal/day), and public supply (39 Bgal/day), cumulatively accounting for 90...

    link

    How much water is used by people in the United States?

    Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories. That data is revised every 5 years.As of 2015, the United States uses 322 billion gallons of water per day (Bgal/day). The three largest water-use categories were irrigation (118 Bgal/day), thermoelectric power (133 Bgal/day), and public supply (39 Bgal/day), cumulatively accounting for 90...

    Learn More
  • Multimedia
    link
    USGS scientist standing with a pole annotated with land-surface elevation marks at given years at bench mark W 990.
    link
    USGS scientist standing with a pole annotated with land-surface elevation marks at given years at bench mark H 1235 RESET.
    link
    Plants in a field
    link
    link
    link
    USGS employee sampling an urban groundwater well
    link
    Irrigation water from a groundwater well on a rice crop field
    link
    Irrigation groundwater well
    link
    Water well windmill
    link
    Groundwater emerging from a cliff
    link
    Illustration of conceptual model of groundwater flow and occurrence.
    link
    Diagram model of a water flow system showing groundwater flow
    link
  • Publications

    Estimated groundwater withdrawals from principal aquifers in the United States, 2015

    In 2015, about 84,600 million gallons per day (Mgal/d) of groundwater were withdrawn in the United States for various uses including public supply, self-supplied domestic, industrial, mining, thermoelectric power, aquaculture, livestock, and irrigation. Of this total, about 94 percent (79,200 Mgal/d) was withdrawn from principal aquifers, which are defined as regionally extensive aquifers or aquif
    By
    Lower Mississippi-Gulf Water Science Center

    Water priorities for the nation—The U.S. Geological Survey next generation water observing system

    The challenges of providing safe and sustainable water supplies for human and ecological uses and protecting lives and property during water emergencies are well recognized. The U.S. Geological Survey (USGS) plays an essential role in meeting these challenges through its observational networks and renowned water science and research activities (National Academies of Science, Engineering, and Medic

    Estimated use of water in the United States in 2015

    Water use in the United States in 2015 was estimated to be about 322 billion gallons per day (Bgal/d), which was 9 percent less than in 2010. The 2015 estimates put total withdrawals at the lowest level since before 1970, following the same overall trend of decreasing total withdrawals observed from 2005 to 2010. Freshwater withdrawals were 281 Bgal/d, or 87 percent of total withdrawals, and salin
    By
    Water Resources, Water Availability and Use Science Program, Maryland-Delaware-D.C. Water Science Center

    The quality of our Nation's waters: Water quality in principal aquifers of the United States, 1991-2010

    About 130 million people in the United States rely on groundwater for drinking water, and the need for high-quality drinking-water supplies becomes more urgent as our population grows. Although groundwater is a safe, reliable source of drinking water for millions of people nationwide, high concentrations of some chemical constituents can pose potential human-health concerns. Some of these contamin
    By
    Water Resources, Colorado Water Science Center

    Summary of estimated water use in the United States in 2010

    About 355,000 million gallons per day (Mgal/d) of water was withdrawn for use in the United States during 2010, a decline of 13 percent from 2005 and a substantial change from the level of about 400,000 Mgal/d reported from 1985 to 2005. Withdrawals for 2010 were lower than withdrawals estimated for 1970. Fresh surface-water withdrawals (230,000 Mgal/d) were almost 15 percent less than in 2005, an
    By
    Water Resources, Water Availability and Use Science Program, South Atlantic Water Science Center (SAWSC)

    Groundwater studies: principal aquifer surveys

    In 1991, the U.S. Congress established the National Water-Quality Assessment (NAWQA) program within the U.S. Geological Survey (USGS) to develop nationally consistent long-term datasets and provide information about the quality of the Nation’s streams and groundwater. The USGS uses objective and reliable data, water-quality models, and systematic scientific studies to assess current water-quality
    By
    Water Resources, California Water Science Center

    What is ground water?

    By
    Water Resources

    Sustainability of ground-water resources

    The pumpage of fresh ground water in the United States in 1995 was estimated to be approximately 77 billion gallons per day (Solley and others, 1998), which is about 8 percent of the estimated 1 trillion gallons per day of natural recharge to the Nation's ground-water systems (Nace, 1960). From an overall national perspective, the ground-water resource appears ample. Locally, however, the availabi
    By
    Water Resources

    Ground water and surface water: A single resource

    The importance of considering ground water and surface water as a single resource has become increasingly evident. Issues related to water supply, water quality, and degradation of aquatic environments are reported on frequently. The interaction of ground water and surface water has been shown to be a significant concern in many of these issues. Contaminated aquifers that discharge to streams can
    By
    Water Resources, Ecosystems, Toxic Substances Hydrology, Environmental Health Program, Dakota Water Science Center

    Ground water and the rural homeowner

    As the salesmen sang in the musical The Music Man, "You gotta know the territory." This saying is also true when planning to buy or build a house. Learn as much as possible about the land, the water supply, and the septic system of the house before buying or building. Do not just look at the construction aspects or the beauty of the home and surroundings. Be sure to consider the environmental cond
    By
    Water Resources
  • News
    link

    Study Estimates about 2.1 Million People using Wells High in Arsenic

    Most Arsenic Presumed to be From Naturally Occurring Sources

    Read Article
    link

    How Well Do You Know Groundwater

    Groundwater, which flows out of sight through aquifers beneath our feet, is one of the Nation’s most important natural resources. In recognition of Na...

    Read Article
    link

    How Much Water Do We Use?

    The USGS National Water-Use Science project has documented 60 years of water-use from 1950 to 2010 in an interactive map.  Choose a year and pick a...

    Read Article
    link

    Helping Desert Communities Find Hidden Water

    Desert communities throughout the Southwest are putting water availability at the top of their municipal agendas.

    Read Article
    link

    Large Precipitation Events are Critical in Replenishing Groundwater Resources

    Large precipitation events that occur about every 10 years are a critical source of recharge for replenishing groundwater resources, according to a ne...

    Read Article