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Real Awesome Aquifers

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Aeration Zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
Porous, water-saturated layers of sand, gravel, or bedrock that transmit and store groundwater.
Cone of Depression
The depression in the water table around a well defining the area of influence of the well.
Confining Layer
A layer of geological material that is impermeable and blocks the flow of groundwater
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
effect where the water table around the well is lowered
Flow Rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes only inches per year.
Groundwater
Water that fills the cracks and spaces in underground soil and rock layers.
Hydrologic Cycle
The water cycle.
Impermeable Layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration Rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Monitoring Well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
Overwithdrawal
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Permeable/Permeability
Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil.
Permeable Layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume
An underground pattern of contaminant concentrations created by the lateral movement of groundwater beneath a contaminant source.
Pore Space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The percentage of the total volume of a rock or sediment that consists of open spaces.
Recharge
Water added to an aquifer; ex. rainfall that seeps into the ground.
Recharge Rate
The quantity of water per unit of time that replenishes or refills an aquifer.
Recharge Zone
An area where permeable soil or rock allows water to seep into the aquifer.
Remediation
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Residence Time
Period of time that groundwater remains in an aquifer.
Safe Yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." Also called sustainable yield.
Salt Water Intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
Saturation Zone
The portion of the earth's crust that's saturated with water. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
Subsidence
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the ground. Subsidence is virtually an irreversible process.
Surface Water
Fresh water found above ground in lakes, ponds, rivers, etc.
Water Table
The underground surface below which the ground is wholly saturated with water.
Well
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
Well Closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well Siting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead Protection Area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Withdrawal
...
Wastewater
Water that contains unwanted material from homes, businesses and industries' a mixture of water and dissolved or suspended substances.
Wastewater Treatment
Any of the mechanical or chemical processes used to modify the quality of wastewater in order to make it more compatible or acceptable to humans and the environment.
Water-bearing Rocks
Several types of rock that can hold water, including: sedimentary deposits (sand and gravel), channels in carbonate rocks (limestone),etc.
Water Quality
The chemical, physical, and biological characteristics of water with respect to its suitability for a particular use.
Water Quality Standards
Recommended or enforceable maximum levels of chemicals or materials in water. (est. by municipalities, industries, etc.)
Watershed
the land are from which surface runoff drains into a stream, channel, lake, reservoir, or other body of water; aka drainage basin.
Water Treatment Plant
Facility that treats water to remove contaminants so that it can be safely used.
Well Field
An are in which productive wells are drilled.
Wetlands
Lands where water saturation is the dominant factor in determining the nature of soil development and types of plant and animal communities. (aka sloughs, ponds, marshes.)
Xeriscaping
an environmentally friendly for of landscaping that uses a variety of indigenous and drought tolerant plants, shrubs, and ground cover.
Aquiclude
Geologic material that hinders or prevents groundwater movement.
Aquifer Storage & Retrieval (ASR)
Use of a well or series of wells to inject surface water into an aquifer during wet weather or low demand periods for purposes of withdrawal and use during drought/high demand periods.
Artificial Recharge
Putting water back into groundwater storage from surface water supplies. (Includes ASR)
Baseflow
Streamflow coming from groundwater seepage into a stream or river. Grounwater flows underground untill the water table intersects the land surface and the flowing water becomes surface water. (Springs, lakes, rivers, streams.)
Best Management Practices (BMP's)
Techniques recognized to be the most effective way of reducing groundwater contamination while still allowing the productive use of the resource.
Brackish
A mixture of salt and freshwater.
Capillary Fringe
The area just above the water table, in the aeration zone, where water moves upward from the water table by capillary action.
Collection Site
A stream, lake, reservoir, or other body of water fed by water drained from a watershed.
Confined Aquifer
An aquifer confined between two layers of impermeable geologic material. When tapped by a well, the water is forced upward, sometimes above the surface.
Conservation
The use of water saving m,ethods to reduce the amount of water needed for day to day use.
Consolidated Rock
Tightly bound geologic formation composed of sandstone, limestone, granite, or other rock.
Consumptive Use.
The use of a resource that reduces the supply.
Contaminant
Any substance that when added to water makes it impure and unfit for consumption or another intended use.
Darcy's Law
Groundwater movement equation developed by Henry Darcy in the mid-1800's.
Diffusion
The movement of a substance from an area of high concentration to an area of low concentration.
Discharge Area
The area or zone where groundwater emerges from an aquifer. The outflow may be into a stream, lake, spring, wetland, etc.
Drought
An extended period of little or no precipitation.
Erosion
The wearing down or washing away of soil and land surface by action of water, wind, or ice.
Evapotranspiration
The loss of water from soil through both evaporation and transpiration from plants.
Filtering
The soil's ability to absorb and retain chemicals or dissolved substances on the surface of it's particles.
Fresh Water
Water with less than .5 parts per thousand dissolved salts.
Gaining Stream
A stream in which groundwater contributes significantly to the streamflow.
Gray Water
Domestic wastewater composed of wash water from household sinks, tubs, and washers.
Groundwater Basin
The underground are from which groundwater drains.
Groundwater Divide
The boundary between two adjacent groundwater basins, represented by a highpoint in the water table.
Groundwater UDI
Groundwater close enough to nearby surface water to recieve direct surface water recharge.
Hydrogeology
The study of the interrelationships of geologic materials and processes with water, esp. groundwater.
Hydrology
The study of the occurence, distribution, and chemistry of all the waters of the earth.
Induced Recharge
The recharge to an aquifer that occurs when a pumping well creates a cone of depression that lowers an adjacent water table below the level of a stream or lake, causing the stream or lake to lose water to the adjacent groundwater aquifer.
Injection Well
A well constructed for the purpose of injecting treated water, often wastewater, directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. Usually not in aquifers used for drinking water.
Integrated Management
Any combination of physical, technical, administrative, and legal practices relating to surface water and groundwater in a manner designed to increase combined benefits or achieve a more equitable apportionment of benefits from both sources. Also referred to as conjunctive use.
Interflow
Water that travels laterally or horizontally through the aeration zone during or immediately after a precipitation event and discharges into a stream or other body of water.
Karst
A geologic formation of irregular limestone deposits with sinks, underground streams, and caverns.
Leachate
Liquids that have percolated through a soil and that carry substances in solution or suspension.
Leaching
The process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals, or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water.
Losing Stream
A stream that is losing water to (or recharging) the groundwater system.
Maximum Contaminant Level (MCL)
Designation given by the U.S. Environmental Protection Agency (EPA) to drinking water standards promulgated under the Safe Drinking Water Act. A MCL is the greatest amount of a contaminant allowed in drinking water without causing a risk to human health.
Mining
See overwithdrawal.
Municipal Water System
A network of pipes, pumps and storage/treatment facilities designed to deliver portable water around a city.
Non-Point Source Pollution(NPS)
Pollution discharged over a wide land area, not from one specific location.
Parallel Flow Paths
: Layers of groundwater flow that do not mix with other flow layers because groundwater movement is too slow to create sufficient turbulence to cause mixing to occur.
Perched Aquifer
Localized zone of saturation above the main water table created by an underlying layer of impermeable material.
Percolation
(1) The movement of water through the openings in rock or soil. (2) The entrance of a portion of the streamflow into the channel materials to contribute to groundwater replenishment.
Point Source Solution (PSP)
Pollutants discharged from any identifiable point, including pipes, ditches, channels, sewers, tunnels, and containers of various types.
Pollution
. The alteration of the physical, chemical, or biological properties of water by the introduction of any substance that renders the water harmful to use.
Potable
Water of a quality suitable for drinking.
Potentiometric Surface
The potential level to which water will rise above the water level in an aquifer in a well that penetrates a confined aquifer; if the potential level is higher than the land surface, the well will overflow.
Reclaimed Wastewater
Treated wastewater that can be used for beneficial purposes, such as irrigating certain plants.
Recycled Water
Water that is used more than one time before it passes back into the natural hydrologic system.
Return Flow
That part of a diverted flow that is not consumptively used and returned to its original source or another body of water.
Ridge Lines
Points of higher ground that separate two adjacent streams or watersheds; also known as divides.
Runoff
Precipitation that flows over land to surface streams, rivers, and lakes
Salinization
The condition in which the salt content of soil accumulates over time to above normal levels
Salt Marsh
A low coastal grassland frequently inundated by the tide.
Saturated Thickness
Total water-bearing thickness of an aquifer.
Seepage
The loss of water by infiltration into the soil from a canal, ditch, lateral, watercourse, reservoir, storage facility, or other body of water, or from a field.
Septic System
Used to treat household sewage and wastewater by allowing the solids to decompose and settle in a tank, then letting the liquid be absorbed by the soil in a drainage field.
Soil
The top layer of the Earth's surface, containing unconsolidated rock and mineral particles mixed with organic material.
Soil Moisture
Water contained in the aeration or unsaturated zone.
Sole Source Aquifer
: An aquifer that supplies 50% or more of the drinking water of an area.
Source Water Assesment
A process in which the land area that impacts a public drinking water source is delineated, possible sources of contaminants that could impact that drinking water source are identified, and a determination of the likelihood that the contaminants will reach the drinking water source is made.
Source Water Protection
Voluntary action taken to prevent the pollution of drinking water sources, including groundwater, lakes, rivers, and streams.
Spring
The emergence of groundwater at the land surface, usually at a clearly defined point; it may flow strongly or just ooze or seep out.
Static Water Level
The level or elevation to which water would rise in a tube connected to an artesian aquifer or basin in a conduit under pressure.
Storm Drain
Constructed opening in a road system through which runoff from the road surface flows into an underground system.
Substrate
A layer of material beneath the surface soil.
Temporary Wetland
A type of wetland in which water is present for only part of the year, usually during wet or rainy seasons; also known as vernal pools.
Thermal Spring
Heated groundwater that naturally flows to the land surface
Transmissivity
A measure of the capability of the entire thickness of an aquifer to transmit water.
Turbidity
A cloudy condition in water due to suspended silt or organic matter.
Unconfined Aquifer
An aquifer in which the water table is at or near atmosphere pressure and is the upper boundary of the aquifer. Because the aquifer is not under pressure the water level in a well is the same as the water table outside the well.
Unconsolidated Rock
Loosely bound geologic formation composed of sands and gravel.
Aeration zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone or vadose zone.
Aquiclude
Impermeable beds of geologic material that hinder or prevent groundwater movement.
Aquifer
An underground geological formation able to store and yield water.
Aquifer storage and retrieval (ASR)
Use of a well or series of wells to inject surface water into an aquifer during wet weather or low demand periods for purposes of withdrawal and use during drought and/or high demand periods.
Artesian well
A well tapping a confined aquifer. Water in the well rises above the top of the aquifer under artesian pressure, but does not necessarily reach the land surface; a flowing one of these is a well in which the water level is above the land surface.
Artificial recharge
Putting water back into groundwater storage from surface water supplies such as irrigation, or induced infiltration from streams or wells. Includes aquifer storage and retrieval (ASR).
Baseflow
Streamflow coming from groundwater seepage into a stream or river. Groundwater flows underground until the water table intersects the land surface and the flowing water becomes surface water in the form of springs, streams/rivers, lakes and wetlands. It is the continual contribution of groundwater to rivers and is an important source of flow between rainstorms.
Best management practices (BMP's)
Structural, nonstructural, and managerial techniques recognized to be the most effective and practical means to reduce surface water and groundwater contamination while still allowing the productive use of resources.
Brackish
Mixed fresh and salt water.
Capillary water
Just above the water table, in the aeration zone, this moves upward from the water table by capillary action. This water can move slowly and in any direction.
Collection site
A stream, lake, reservoir, or other body of water fed by water drained from a watershed.
Condensation
The process in the hydrologic cycle by which a vapor becomes a liquid; the opposite of evaporation.
Cone of depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well. The land surface overlying the cone of depression is referred to as the area of influence.
Confined aquifer
A body of groundwater surrounded by confining layers
Confining layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Conservation
The use of water-saving methods to reduce the amount of water needed for homes, lawns, farming, and industry, and thus increasing water supplies for optimum long-term economic and social benefits.
Consolidated rock
Tightly bound geologic formation composed of sandstone, limestone, granite, or other rock.
Consumptive use
The use of a resource that reduces the supply (removing water from a source like a river, lake or aquifer without returning an equal amount). Examples include the intake of water by plants, humans, and other animals and the incorporation of water into the products of industrial or food processing.
Contaminant
Any substance that when added to water (or another substance) makes it impure and unfit for consumption or an intended use.
Darcy's Law
A groundwater movement equation formulated by Henry Darcy during the mid-1800's based on experiments on the flow of water through beds of sand. It forms the scientific basis of fluid permeability used in earth science.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Diffusion
The movement of a substance from an area of high concentration to an area of low concentration.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Discharge area
The area or zone where groundwater emerges from the aquifer. The outflow maybe into a stream, lake, spring, wetland, etc.
Drawdown
A lowering of the groundwater level caused by pumping.
Drought
An extended period with little or no precipitation; often affects crop production and availability of water supplies.
Erosion
The wearing down or washing away of the soil and land surface by the action of water, wind, or ice.
Evaporation
The conversion of a liquid (water) into a vapor (a gaseous state) usually through the application of heat energy during the hydrologic cycle; the opposite of condensation.
Evapotranspiration
The loss water from the soil through both evaporation and transpiration from plants.
Filtering
The soil's ability to attenuate substances by retaining chemicals or dissolved substances on the soil particle surface, transforming chemicals through microbial biological processing, retarding movement, and capturing solid particles.
Flow rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes as little as inches per year.
Fresh water
Water with less than 0.5 parts per thousand dissolved salts.
Gaining stream
A stream in which groundwater discharges contribute significantly to the streamflow volume.
Gray water
Domestic wastewater composed of wash water from household sinks, tubs, and washers.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). It is a natural resource that is used for drinking, recreation, industry, and growing crops.
Groundwater basin
The underground area from which groundwater drains. These basins could be separated by geologic or hydrologic boundaries.
Groundwater divide
The boundary between two adjacent groundwater basins, which is represented by a high point in the water table.
Groundwater under the direct influence (UDI) of surface water
A groundwater source located close enough to nearby surface water, such as a river or lake, to receive direct surface water recharge. Since a portion of the groundwater source's recharge is from surface water, the groundwater is at risk of contamination from pathogens such as Giardia lamblia and viruses, which are not normally found in groundwater.
Hydrogeology
The study of the interrelationships of geologic materials and processes with water, especially groundwater.
Hydrologic cycle
The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Hydrology
The study of the occurrence, distribution, and chemistry of all waters of the earth.
Impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Induced recharge
The recharge to an aquifer that occurs when a pumping well creates a cone of depression that lowers an adjacent water table below the level of a stream or lake, causing the stream or lake to lose water to the adjacent groundwater aquifer.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Injection well
A well constructed for the purpose of injecting treated water, often wastewater, directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. They are generally drilled into aquifers that are not used as a drinking water source, unused aquifers, or below freshwater levels.
Integrated management
Any combination of physical, technical, administrative, and legal practices relating to surface water and groundwater in a manner designed to increase combined benefits or achieve a more equitable apportionment of benefits from both sources. Also referred to as conjunctive use.
Interflow
Water that travels laterally or horizontally through the aeration zone during or immediately after a precipitation event and discharges into a stream or other body of water.
Irrigation
The controlled application of water to cropland, hay fields, and/or pasture to supplement that supplied by nature.
Karst
A geologic formation of irregular limestone deposits that dissolve forming sink holes, underground streams, and caverns.
Leachate
Liquids that have percolated through a soil and that carry substances in solution or suspension.
Leaching
The process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals, or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water.
Liquid
The part of the hydrologic cycle in which molecules move freely among themselves but do not separate like those in a vapor/gaseous state.
Losing stream
A stream that is losing water to (or recharging) the groundwater system.
Maximum contaminant level (MCL)
Designation given by the U.S. Environmental Protection Agency (EPA) to drinking water standards promulgated under the Safe Drinking Water Act. It is the greatest amount of a contaminant allowed in drinking water without causing a risk to human health.
Monitoring well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality. A piezometer, which is open only at the top and bottom of its casing, is one type of this.
Municipal water system
A network of pipes, pumps, and storage and treatment facilities designed to deliver potable water to homes, schools, businesses, and other users in a city or town and to remove and treat waste materials.
Nonpoint source (NPS) pollution
Pollution discharged over a wide land area, not from one specific location.
Overwithdrawal
Withdrawal (removal) of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Parallel flow paths
Layers of groundwater flow that do not mix with other flow layers because groundwater movement is too slow to create sufficient turbulence to cause mixing to occur. This becomes an important factor in the location and movement of contaminants that enter the groundwater.
Perched aquifer
Localized zone of saturation above the main water table created by an underlying layer of impermeable material.
Percolation
(1) The movement of water through the openings in rock or soil. (2) The entrance of a portion of the streamflow into the channel materials to contribute to groundwater replenishment.
Permeable/Permeability
Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil.
Permeable layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume
An underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Point source pollution
Pollutants discharged from any identifiable point, including pipes, ditches, channels, sewers, tunnels, and containers of various types.
Pollution
An alteration in the character or quality of the environment, or any of its components, that renders it less suited for certain uses. The alteration of the physical, chemical, or biological properties of water by the introduction of any substance that renders the water harmful to use.
Pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated small grain sand contains less water than coarse gravel.
Potable water
Water of a quality suitable for drinking.
Potentiometric surface
The potential level to which water will rise above the water level in an aquifer in a well that penetrates a confined aquifer; if the potential level is higher than the land surface, the well will overflow. See artesian well and confined aquifer.
Precipitation
The part of the hydrologic cycle when water falls, in a liquid or solid state, from the atmosphere to Earth (rain, snow, sleet).
Recharge
Water added to an aquifer. For example, when rainwater seeps into the ground. It may occur artificially through injection wells or by spreading water over groundwater reservoirs.
Recharge rate
The quantity of water per unit of time that replenishes or refills an aquifer.
Recharge zone or area
An area where permeable soil or rock allows water to seep into the ground to replenish an aquifer.
Reclaimed wastewater
Treated wastewater that can be used for beneficial purposes, such as irrigating certain plants.
Recycled water
Water that is used more than one time before it passes back into the natural hydrologic system.
Remediation
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Residence time
Period of time that groundwater remains in an aquifer.
Return flow
(1) That part of a diverted flow that is not consumptively used and returned to its original source or another body of water. (2) Irrigation water that is applied to an area and which is not consumed in evaporation or transpiration and returns to a surface stream or aquifer.
Ridge lines
Points of higher ground that separate two adjacent streams or watersheds; also known as divides.
Runoff
Precipitation that flows over land to surface streams, rivers, and lakes.
Safe yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years."
Salinization
The condition in which the salt content of soil accumulates over time to above normal levels; occurs in some parts of the world where water containing high salt concentration evaporates from fields irrigated with standing water.
Salt marsh
A low coastal grassland frequently inundated by the tide.
Salt water
Water that contains a relatively high percentage (over 0.5 parts per thousand) of salt minerals.
Salt water intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
Saturated thickness
Total water-bearing thickness of an aquifer.
Saturation zone
The portion below the earth's surface that is saturated with water . The upper surface of this zone, open to atmospheric pressure, is known as the water table.
Seepage
(1) The slow movement of water into or out of a body of surface or subsurface water. (2) The loss of water by infiltration into the soil from a canal, ditch, lateral, watercourse, reservoir, storage facility, or other body of water, or from a field.
Septic system
This is used to treat household sewage and wastewater by allowing the solids to decompose and settle in a tank, then letting the liquid be absorbed by the soil in a drainage field.
Soil
The top layer of the Earth's surface, containing unconsolidated rock and mineral particles mixed with organic material.
Soil moisture
Water contained in the aeration or unsaturated zone.
Sole source aquifer
An aquifer that supplies 50% or more of the drinking water of an area.
Source water assessment
A process in which the land area that impacts a public drinking water source is delineated, possible sources of contaminants that could impact that drinking water source are identified, and a determination of the likelihood that the contaminants will reach the drinking water source is made.
Source water protection
Voluntary action taken to prevent the pollution of drinking water sources, including groundwater, lakes, rivers, and streams.
Spring
The emergence of groundwater at the land surface, usually at a clearly defined point; it may flow strongly or just ooze or seep out.
Static water level
(1) Elevation or level of the water table in a well when the pump is not operating. (2) The level or elevation to which water would rise in a tube connected to an artesian aquifer or basin in a conduit under pressure.
Storm drain
Constructed opening in a road system through which runoff from the road surface flows into an underground system.
Strata
A layer within the earth's crust that generally consists of the same kinds of soils or rock material.
Sublimation
The transition of a substance from the solid phase directly to the vapor phase, or vice versa, without passing through an intermediate liquid phase.
Subsidence
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the land. It is virtually an irreversible process.
Substrate
A layer of material beneath the surface soil.
Surface water
Water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Temporary wetland
A type of wetland in which water is present for only part of the year, usually during wet or rainy seasons; also known as vernal pools.
Thermal spring
Heated groundwater that naturally flows to the land surface.
Transmissivity
A measure of the capability of the entire thickness of an aquifer to transmit water.
Transpiration
The process by which water absorbed by plants (usually through the roots) is evaporated into the atmosphere from the plant surface (principally from the leaves).
Turbidity
A cloudy condition in water due to suspended silt or organic matter.
Unconfined aquifers
An aquifer in which the water table is at or near atmosphere pressure and is the upper boundary of the aquifer. Because the aquifer is not under pressure the water level in a well is the same as the water table outside the well.
Unconsolidated rock
Loosely bound geologic formation composed of sands and gravel.
Vapor
The state of water in the hydrologic cycle in which individual molecules are highly energized and move about freely; also known as gas/gaseous
Wastewater
Water that contains unwanted materials from homes, businesses, and industries; a mixture of water and dissolved or suspended substances.
Wastewater treatment
Any of the mechanical or chemical processes used to modify the quality of wastewater in order to make it more compatible or acceptable to humans and the environment.
Water
An odorless, tasteless, colorless liquid made up of a combination of hydrogen and oxygen. It forms streams, lakes, and seas, and is a major constituent of all living matter.
Water-bearing rocks
A rock that can bear water
Water quality
The chemical, physical, and biological characteristics of water with respect to its suitability for a particular use.
Water quality standards
Recommended or enforceable maximum contaminant levels of chemicals or materials (such as chlorobenzene, nitrate, iron, arsenic) in water. These levels are established for water used by municipalities, industries, agriculture, and recreationists.
Watershed
The land area from which surface runoff drains into a stream, channel, lake, reservoir, or other body of water; also called a drainage basin.
Water table
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. The upper surface of the saturation zone.
Water treatment plant
A facility that treats water to remove contaminants so that it can be safely used.
Well
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
Well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well field
An area in which productive wells are drilled.
Well siting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead protection area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Wetlands
Lands where water saturation is the dominant factor in determining the nature of soil development and the types of plant and animal communities.
Withdrawal
Water removed from a surface or groundwater source for use.
Xeriscaping
An environmentally friendly form of landscaping that uses a variety of indigenous and drought-tolerant plants, shrubs, and ground cover.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Diffusion
The movement of a substance from an area of high concentration to an area of low concentration.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Discharge area
The area or zone where groundwater emerges from the aquifer. The outflow maybe into a stream, lake, spring, wetland, etc.
Drawdown
A lowering of the groundwater level caused by pumping.
Drought
An extended period with little or no precipitation; often affects crop production and availability of water supplies.
An extended period with little or no precipitation; often affects crop production and availability of water supplies.
The wearing down or washing away of the soil and land surface by the action of water, wind, or ice.
Evaporation
The conversion of a liquid (water) into a vapor (a gaseous state) usually through the application of heat energy during the hydrologic cycle; the opposite of condensation.
Evapotranspiration
The loss water from the soil through both evaporation and transpiration from plants.
Filtering
The soil's ability to attenuate substances by retaining chemicals or dissolved substances on the soil particle surface, transforming chemicals through microbial biological processing, retarding movement, and capturing solid particles.
Flow rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes as little as inches per year.
Fresh water
Water with less than 0.5 parts per thousand dissolved salts.
Gaining stream
A stream in which groundwater discharges contribute significantly to the streamflow volume. The same stream could be both a gaining stream and a losing stream, depending on the conditions.
Gas (gaseous)
The state of water in the hydrologic cycle in which individual molecules are highly energized and move about freely; also known as gas/gaseous.
Gray water
Domestic wastewater composed of wash water from household sinks, tubs, and washers.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Groundwater basin
The underground area from which groundwater drains. The basins could be separated by geologic or hydrologic boundaries.
Groundwater divide
The boundary between two adjacent groundwater basins, which is represented by a high point in the water table.
Groundwater under the direct influence (UDI) of surface water
A groundwater source located close enough to nearby surface water, such as a river or lake, to receive direct surface water recharge. Since a portion of the groundwater source's recharge is from surface water, the groundwater is at risk of contamination from pathogens such as Giardia lamblia and viruses, which are not normally found in groundwater.
Hydrogeology
The study of the interrelationships of geologic materials and processes with water, especially groundwater.
Hydrologic cycle
(also known as the water cycle) The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Hydrology
The study of the occurrence, distribution, and chemistry of all waters of the earth.
Impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Induced recharge
The recharge to an aquifer that occurs when a pumping well creates a cone of depression that lowers an adjacent water table below the level of a stream or lake, causing the stream or lake to lose water to the adjacent groundwater aquifer.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Injection well
A well constructed for the purpose of injecting treated water, often wastewater, directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. Injection wells are generally drilled into aquifers that are not used as a drinking water source, unused aquifers, or below freshwater levels.
aeration zone
the zone immediately below the lands surface where the pores contain both water and air but are not totally saturated with water. plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
aquifer
underground bed or layer yielding ground water for wells and springs etc
cone of depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
confining layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
drawdown
A lowering of the groundwater level caused by pumping.
flow rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes only inches per year.
groundwater
water that fills tiny cracks and holes in the rock layers below the earth's surface
hydrologic cycle
(also known as the water cycle) The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
infiltration
Flow of water from the land surface into the subsurface.
infiltration rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
monitoring well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
overwithdrawal
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
permeable
capable of transmitting water the rate at which water moves through rocks or soil
permeable layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated sand contains about 20% water; gravel, 25%; and clay, 48%.
recharge
new water that enters the aquifer from the surface
recharge rate
The quantity of water per unit of time that replenishes or refills an aquifer. Recharge zone or area: An area where permeable soil or rock allows water to seep into the
recharge zone or area
An area where permeable soil or rock allows water to deep into the ground to replenish an aquifer.
remediation
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
residence time
the average amount of time that a nutrient spends in a given source or pool.
safe yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." Also called sustainable yield.
salt water intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
saturation zone
The portion below the earth's surface that is saturated with water is called the zone of saturation. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
subsidence
a depression of the land surface as a result of groundwater being pumped
surface water
water above the surface of the land, including lakes, rivers,etc.
water table
the top of an aquifer
well
a bored,drilled or driven shaft or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
well siting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
wellhead protection area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
withdrawal
water removed from a surface or groundwater source for use
plume
in groundwater a plume is an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Aeration Zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
underground bed or layer yielding ground water for wells and springs etc
Cone of Depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
Confining Layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
an outflow of water from stream, pipe, groundwater aquifer, or watershed; the opposite of recharge
Drawdown
a lowering of the groundwater level caused by pumping
Flow Rate
the time required for a volume of groundwater to move between points. Typically groundwater moves very slowly- sometimes only inches per year
Groundwater
water found in the spaces between soil particles and cracks in rock underground( located in the saturated zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Hydrological Cycle( also known as the water cycle)
the paths water take through its various states-vapor, liquid, solid- as it moves throughout the oceans, atmosphere, groundwater, streams, etc...
Impermeable Layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Infiltration
flow of water from the land surface into the subsurface.
Infiltration Rate
the quantity of water that enters the soil surface in a specified time interval, often expressed in volume of water per unit of soil surface area per unit of time.
Monitoring Well
a non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
Overwithdrawl
withdrawl of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also, referred to as overdraft or mining the aquifer.
Aeration zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone or vadose zone.
Aquiclude:
: Impermeable beds of geologic material that hinder or prevent groundwater movement
Aquifer:
An underground geological formation able to store and yield water.
Aquifer storage and retrieval (ASR):
Use of a well or series of wells to inject surface water into an aquifer during wet weather or low demand periods for purposes of withdrawal and use during drought and/or high demand periods.
Artesian aquifer:
See confined aquifer.
Artesian well:
A well tapping a confined aquifer. Water in the well rises above the top of the aquifer under artesian pressure, but does not necessarily reach the land surface; a flowing artesian well is a well in which the water level is above the land surface.
Artificial recharge:
Putting water back into groundwater storage from surface water supplies such as irrigation, or induced infiltration from streams or wells. Includes aquifer storage and retrieval (ASR).
Baseflow:
Streamflow coming from groundwater seepage into a stream or river. Groundwater flows underground until the water table intersects the land surface and the flowing water becomes surface water in the form of springs, streams/rivers, lakes and wetlands. Baseflow is the continual contribution of groundwater to rivers and is an important source of flow between rainstorms.
Best management practices (BMP's):
Structural, nonstructural, and managerial techniques recognized to be the most effective and practical means to reduce surface water and groundwater contamination while still allowing the productive use of resources.
Brackish:
Mixed fresh and salt water.
Capillary water:
Just above the water table, in the aeration zone, is capillary water that moves upward from the water table by capillary action. This water can move slowly and in any direction. While most plants rely upon moisture from precipitation that is present in the unsaturated zone, their roots may also tap into capillary water or into the underlying saturated zone.
Collection site:
A stream, lake, reservoir, or other body of water fed by water drained from a watershed.
Condensation:
The process in the hydrologic cycle by which a vapor becomes a liquid; the opposite of evaporation.
Cone of depression:
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well. The land surface overlying the cone of depression is referred to as the area of influence.
Confined aquifer:
(also known as artesian or pressure aquifers) exist where the groundwater is bounded between layers of impermeable substances like clay or dense rock. When tapped by a well, water in confined aquifers is forced up, sometimes above the soil surface. This is how a flowing artesian well is formed.
Confining layer:
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Conservation:
The use of water-saving methods to reduce the amount of water needed for homes, lawns, farming, and industry, and thus increasing water supplies for optimum long-term economic and social benefits.
Consolidated rock:
Tightly bound geologic formation composed of sandstone, limestone, granite, or other rock.
Consumptive use:
The use of a resource that reduces the supply (removing water from a source like a river, lake or aquifer without returning an equal amount). Examples include the intake of water by plants, humans, and other animals and the incorporation of water into the products of industrial or food processing.
Contaminant:
Any substance that when added to water (or another substance) makes it impure and unfit for consumption or an intended use.
Darcy's Law:
A groundwater movement equation formulated by Henry Darcy during the mid-1800's based on experiments on the flow of water through beds of sand. Darcy's Law forms the scientific basis of fluid permeability used in earth science.
Depletion:
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Diffusion:
The movement of a substance from an area of high concentration to an area of low concentration.
Discharge:
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Discharge area:
The area or zone where groundwater emerges from the aquifer. The outflow maybe into a stream, lake, spring, wetland, etc.
Drawdown:
A lowering of the groundwater level caused by pumping.
Drought:
An extended period with little or no precipitation; often affects crop production and availability of water supplies.
Erosion:
The wearing down or washing away of the soil and land surface by the action of water, wind, or ice.
Evaporation:
The conversion of a liquid (water) into a vapor (a gaseous state) usually through the application of heat energy during the hydrologic cycle; the opposite of condensation.
Evapotranspiration:
The loss water from the soil through both evaporation and transpiration from plants.
Filtering:
The soil's ability to attenuate substances by retaining chemicals or dissolved substances on the soil particle surface, transforming chemicals through microbial biological processing, retarding movement, and capturing solid particles.
Flow rate:
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes as little as inches per year.
Fresh water:
Water with less than 0.5 parts per thousand dissolved salts.
Gaining stream:
A stream in which groundwater discharges contribute significantly to the streamflow volume. The same stream could be both a gaining stream and a losing stream, depending on the conditions.
Gas (gaseous):
See vapor.
Gray water:
Domestic wastewater composed of wash water from household sinks, tubs, and washers.
Groundwater:
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Groundwater basin:
The underground area from which groundwater drains. The basins could be separated by geologic or hydrologic boundaries.
Groundwater divide:
The boundary between two adjacent groundwater basins, which is represented by a high point in the water table.
Groundwater under the direct influence (UDI) of surface water:
A groundwater source located close enough to nearby surface water, such as a river or lake, to receive direct surface water recharge. Since a portion of the groundwater source's recharge is from surface water, the groundwater is at risk of contamination from pathogens such as Giardia lamblia and viruses, which are not normally found in groundwater.
Hydrogeology:
The study of the interrelationships of geologic materials and processes with water, especially groundwater.
Hydrologic cycle:
(also known as the water cycle) The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Hydrology:
The study of the occurrence, distribution, and chemistry of all waters of the earth.
Impermeable layer:
A layer of material (such as clay) in an aquifer through which water does not pass.
Induced recharge:
The recharge to an aquifer that occurs when a pumping well creates a cone of depression that lowers an adjacent water table below the level of a stream or lake, causing the stream or lake to lose water to the adjacent groundwater aquifer.
Infiltration:
Flow of water from the land surface into the subsurface.
Infiltration rate:
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Injection well:
A well constructed for the purpose of injecting treated water, often wastewater, directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. Injection wells are generally drilled into aquifers that are not used as a drinking water source, unused aquifers, or below freshwater levels.
Integrated management:
Any combination of physical, technical, administrative, and legal practices relating to surface water and groundwater in a manner designed to increase combined benefits or achieve a more equitable apportionment of benefits from both sources. Also referred to as conjunctive use.
Interflow:
Water that travels laterally or horizontally through the aeration zone during or immediately after a precipitation event and discharges into a stream or other body of water.
Irrigation:
The controlled application of water to cropland, hay fields, and/or pasture to supplement that supplied by nature.
Karst:
A geologic formation of irregular limestone deposits that dissolve forming sink holes, underground streams, and caverns.
Leachate:
Liquids that have percolated through a soil and that carry substances in solution or suspension.
Leaching:
The process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals, or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water.
Liquid:
The part of the hydrologic cycle in which molecules move freely among themselves but do not separate like those in a vapor/gaseous state.
Losing stream:
A stream that is losing water to (or recharging) the groundwater system. The same stream could be both a gaining stream and a losing stream, depending on the conditions.
Maximum contaminant level (MCL):
Designation given by the U.S. Environmental Protection Agency (EPA) to drinking water standards promulgated under the Safe Drinking Water Act. A MCL is the greatest amount of a contaminant allowed in drinking water without causing a risk to human health.
Mining:
See overwithdrawal
Monitoring well:
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality. A piezometer, which is open only at the top and bottom of its casing, is one type of monitoring well.
Municipal water system:
A network of pipes, pumps, and storage and treatment facilities designed to deliver potable water to homes, schools, businesses, and other users in a city or town and to remove and treat waste materials.
Nonpoint source (NPS) pollution
Pollution discharged over a wide land area, not from one specific location. These are forms of diffuse pollution caused by sediment, nutrients, organic and toxic substances originating from land use activities which are carried to lakes and streams by surface runoff. Nonpoint source pollution is contamination that occurs when rainwater, snowmelt, or irrigation washes off plowed fields, city streets, or suburban backyards. As this runoff moves across the land surface, it picks up soil particles and pollutants, such as nutrients and pesticides.
Overwithdrawal:
Withdrawal (removal) of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Parallel flow paths:
Layers of groundwater flow that do not mix with other flow layers because groundwater movement is too slow to create sufficient turbulence to cause mixing to occur. This becomes an important factor in the location and movement of contaminants that enter the groundwater.
Perched aquifer:
Localized zone of saturation above the main water table created by an underlying layer of impermeable material.
Percolation:
(1) The movement of water through the openings in rock or soil. (2) The entrance of a portion of the streamflow into the channel materials to contribute to groundwater replenishment.
Permeable/Permeability:
Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil.
Permeable layer:
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume:
In groundwater a plume is an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Point source pollution:
Pollutants discharged from any identifiable point, including pipes, ditches, channels, sewers, tunnels, and containers of various types.
Pollution:
An alteration in the character or quality of the environment, or any of its components, that renders it less suited for certain uses. The alteration of the physical, chemical, or biological properties of water by the introduction of any substance that renders the water harmful to use.
Pore space:
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity:
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated small grain sand contains less water than coarse gravel.
Potable water:
Water of a quality suitable for drinking.
Potentiometric surface:
The potential level to which water will rise above the water level in an aquifer in a well that penetrates a confined aquifer; if the potential level is higher than the land surface, the well will overflow. See artesian well and confined aquifer.
Precipitation:
The part of the hydrologic cycle when water falls, in a liquid or solid state, from the atmosphere to Earth (rain, snow, sleet).
Recharge:
Water added to an aquifer. For example, when rainwater seeps into the ground. Recharge may occur artificially through injection wells or by spreading water over groundwater reservoirs.
Recharge rate:
The quantity of water per unit of time that replenishes or refills an aquifer.
Recharge zone or area:
An area where permeable soil or rock allows water to seep into the ground to replenish an aquifer.
Reclaimed wastewater:
Treated wastewater that can be used for beneficial purposes, such as irrigating certain plants.
Recycled water:
Water that is used more than one time before it passes back into the natural hydrologic system.
Remediation:
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Residence time:
Period of time that groundwater remains in an aquifer.
Return flow:
(1) That part of a diverted flow that is not consumptively used and returned to its original source or another body of water. (2) Irrigation water that is applied to an area and which is not consumed in evaporation or transpiration and returns to a surface stream or aquifer.
Ridge lines:
Points of higher ground that separate two adjacent streams or watersheds; also known as divides.
Runoff:
Precipitation that flows over land to surface streams, rivers, and lakes.
Safe yield:
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years."
Salinization:
The condition in which the salt content of soil accumulates over time to above normal levels; occurs in some parts of the world where water containing high salt concentration evaporates from fields irrigated with standing water.
Salt marsh:
A low coastal grassland frequently inundated by the tide.
Salt water:
Water that contains a relatively high percentage (over 0.5 parts per thousand) of salt minerals.
Salt water intrusion:
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
Saturated thickness:
Total water-bearing thickness of an aquifer.
Saturation zone:
The portion below the earth's surface that is saturated with water is called the zone of saturation. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
Seepage:
(1) The slow movement of water into or out of a body of surface or subsurface water. (2) The loss of water by infiltration into the soil from a canal, ditch, lateral, watercourse, reservoir, storage facility, or other body of water, or from a field.
Septic system:
Used to treat household sewage and wastewater by allowing the solids to decompose and settle in a tank, then letting the liquid be absorbed by the soil in a drainage field. Septic systems are used when a sewer line is not available to carry wastes to a sewage treatment plan. Also called an onsite wastewater treatment system.
Soil:
The top layer of the Earth's surface, containing unconsolidated rock and mineral particles mixed with organic material.
Soil moisture:
Water contained in the aeration or unsaturated zone.
Sole source aquifer:
An aquifer that supplies 50% or more of the drinking water of an area.
Source water assessment:
A process in which the land area that impacts a public drinking water source is delineated, possible sources of contaminants that could impact that drinking water source are identified, and a determination of the likelihood that the contaminants will reach the drinking water source is made. The federal Safe Drinking Water Act requires states to provide each public water system with a source water assessment. Public water systems are then required to make the assessments available to the public. A community may verify, refine or expand the list of potential contaminants. See source water protection.
Source water protection:
Voluntary action taken to prevent the pollution of drinking water sources, including groundwater, lakes, rivers, and streams. Source water protection is developing and implementing a plan to manage land uses and potential contaminants. To be effective, source water protection should be directed to major threats to the drinking water source identified in the source water assessment. As part of the source water protection plan, a contingency plan for use in the event of an emergency is developed. Source water protection for groundwater is also called wellhead protection. See source water assessment.
Spring:
The emergence of groundwater at the land surface, usually at a clearly defined point; it may flow strongly or just ooze or seep out.
Static water level:
(1) Elevation or level of the water table in a well when the pump is not operating. (2) The level or elevation to which water would rise in a tube connected to an artesian aquifer or basin in a conduit under pressure.
Storm drain:
Constructed opening in a road system through which runoff from the road surface flows into an underground system.
Stratum, pl. strata:
A layer within the earth's crust that generally consists of the same kinds of soils or rock material.
Sublimation:
The transition of a substance from the solid phase directly to the vapor phase, or vice versa, without passing through an intermediate liquid phase.
Subsidence:
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the land. Subsidence is virtually an irreversible process.
Sustainable yield:
See safe yield.
Substrate:
A layer of material beneath the surface soil.
Surface water:
Water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Temporary wetland:
A type of wetland in which water is present for only part of the year, usually during wet or rainy seasons; also known as vernal pools.
Thermal spring:
Heated groundwater that naturally flows to the land surface.
Transmissivity:
A measure of the capability of the entire thickness of an aquifer to transmit water. Also known as coefficient of transmissivity.
Transpiration:
The process by which water absorbed by plants (usually through the roots) is evaporated into the atmosphere from the plant surface (principally from the leaves).
Turbidity:
A cloudy condition in water due to suspended silt or organic matter.
Unconfined aquifers:
An aquifer in which the water table is at or near atmosphere pressure and is the upper boundary of the aquifer. Because the aquifer is not under pressure the water level in a well is the same as the water table outside the well.
Unconsolidated rock:
Loosely bound geologic formation composed of sands and gravel.
Unsaturated zone:
See aeration zone.
Vapor:
The state of water in the hydrologic cycle in which individual molecules are highly energized and move about freely; also known as gas/gaseous.
Wastewater:
Water that contains unwanted materials from homes, businesses, and industries; a mixture of water and dissolved or suspended substances.
Wastewater treatment:
Any of the mechanical or chemical processes used to modify the quality of wastewater in order to make it more compatible or acceptable to humans and the environment.
Water (H2O):
An odorless, tasteless, colorless liquid made up of a combination of hydrogen and oxygen. Water forms streams, lakes, and seas, and is a major constituent of all living matter.
Water-bearing rocks:
Several types of rocks can hold water, including: sedimentary deposits (sand and gravel), channels in carbonate rocks (limestone), lava tubes or cooling fractures in igneous rocks, and fractures in hard rocks.
Water cycle:
See hydrologic cycle.
Water quality:
The chemical, physical, and biological characteristics of water with respect to its suitability for a particular use.
Water quality standards:
Recommended or enforceable maximum contaminant levels of chemicals or materials (such as chlorobenzene, nitrate, iron, arsenic) in water. These levels are established for water used by municipalities, industries, agriculture, and recreationists.
Watershed:
The land area from which surface runoff drains into a stream, channel, lake, reservoir, or other body of water; also called a drainage basin.
Water table:
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. The upper surface of the saturation zone.
Water treatment plant:
A facility that treats water to remove contaminants so that it can be safely used.
Well:
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
Well closure:
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well field:
An area in which productive wells are drilled.
Well siting:
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead protection area:
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Wetlands:
Lands where water saturation is the dominant factor in determining the nature of soil development and the types of plant and animal communities. Other common names for wetlands are sloughs, ponds, and marshes.
Withdrawal:
Water removed from a surface or groundwater source for use.
Xeriscaping:
An environmentally friendly form of landscaping that uses a variety of indigenous and drought-tolerant plants, shrubs, and ground cover.
Aquifer
Underground geological formations capable of storing and yielding water.
Area of influence
The land surface overlying the cone of depression.
Artesian well
A well tapping a confined aquifer. The water in the well does not need to be pumped because it is under pressure and forced up naturally.
Condensation
The process in the hydrologic cycle by which a vapor becomes a liquid; the opposite of evaporation.
Cone of depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped.
Confined aquifer
Groundwater that is bound between layers of impermeable substances like clay or dense rock.
Confining layer
Geologic material with little or no permeability, water does not pass through this layer or the rate of movement is extremely slow.
Conservation (Water Conservation)
The use of water-saving methods to reduce the amount of water needed for homes, lawns, farming, and industry.
Contaminant
Any substance that when added to water (or another substance) makes it impure and potentially unfit for consumption or use.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
The lowering of the groundwater level cause by pumping.
Drought
an extended period with little or no precipitation.
Evaporation
The conversion of a liquid (water) into a vapor or gaseous state) usually through the application of heat energy during the hydrologic cycle.
Flow rate
The time required for a volume of groundwater to move between points.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Groundwater quality
The chemical, physical, and biological characteristics of groundwater with respect to its suitability of a particular use.
Groundwater under the direct influence
A source of groundwater located close enough to surface water to receive direct surface water recharge.
Hydrogeology
The study of groundwater.
Hydrologic cycle.
(Also known as water cycle) The paths above and below the earth's surface that water takes through its various states - vapor, liquid, and solid - as it moves through the ocean, atmosphere, groundwater, etc.
Hydrology
The study of all waters of teh Earth.
Impermeable
A material which water cannot pass through.
Infiltration
The process of water soaking into the soil and sub-layers.
Leachate
Liquids that percolate through soil while carrying undesirable substances or contaminants.
Monitoring well
A non-pumping well, generally of small diameter, that is used specifically to measure the elevation of the water table and analyze water quality.
Nonpoint source pollution
Pollution discharged over a wide land area, not from one specific location.
Overwithdrawal
Removal of groundwater over a period of time that exceeds the recharge rate.
Percolation
The movement of water through the openings in rock or soil.
Permeable/ Permeability
Capable of transmitting water (porous rocks, sediment, or soil); the rate at which water moves through rocks or soil.
Plume
An underground pattern of contaminant concentration created by the movement of groundwater beneath a contaminant source.
Point source pollution
Pollutants discharged from any identifiable point.
Pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated small grain sand contains less water than coarse gravel. Describes or measures the open or void spaces in rocks or sediment.
Precipitation
The part of the hydrologic cycle when water falls, in a liquid or solid state, from the atmosphere to earth (rain, snow, sleet).
Recharge
Groundwater supplies are replenished, or recharged, when water such as rain or snow melt is added to an aquifer.
Remediation
Containment, treatment of removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Runoff
Precipitation that flows across the surface of the land to streams, rivers, and lakes.
Safe yield
The amount of water that can be taken from a source of supply over a period off years without depleting the source beyond its ability to be replenished naturally. Also referred to as sustainable yield.
Saturation zone
The portion of the earth's crust that's saturated with water is call the zone of saturation. the upper surface of this zone, open to atmospheric pressure, is known as the water table.
Surface water
water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Transpiration
The process by which water absorbed by plant roots is evaporated into the atmosphere from plant leaves.
Unconfined aquifer
An aquifer containing groundwater that is bellow porous materials such as soil, sand, and gravel.
Unsaturated zone
The zone immediately below the land surface where the pores contain both water and air, but are not completely saturated or soaked with water. Also referred to as the aeration zone or vadose zone.
Water table
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water.
Water treatment
The processes of making water more acceptable for a desired use (for drinking, industrial processes, or to discharge into the environment without adverse impact).
Well
A hole drilled or bored into the earth to obtain water.
Well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well screen
Part of a well constructed to prevent sediment and rock particles from clogging the well and from being pumped into the water supply.
Well siting
The process of selecting a location (or site) to install a well that will allow access to adequate water quantity and offer protection to water quality.
Withdrawal
The removal of water from a surface water of groundwater source.
Bedrock
The solid rock beneath the soil and superficial rock.
Aquifer
A geological formation or structure that stores and/or transmits water, such as to wells and springs.
bedrock
the solid rock beneath the soil and superficial rock.
discharge
the volume of water that passes a given location within a given period of time.
draw down
a lowering of the ground-water surface caused by pumping.
ground water
water that flows or seeps downward and saturates soil or rock, supplying springs and wells.
hydrologic cycle
the cyclic transfer of water vapor from the Earth's surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to earth, and through runoff into streams, rivers, and lakes, and ultimately into the oceans.
impermeable layer
a layer of solid material, such as rock or clay, which does not allow water to pass through.
infiltration
flow of water from the land surface into the subsurface.
permeability
the ability of a material to allow the passage of a liquid, such as water through rocks. Permeable materials, such as gravel and sand, allow water to move quickly through them, whereas unpermeable material, such as clay, don't allow water to flow freely.
recharge
water added to an aquifer. For instance, rainfall that seeps into the ground.
Saturated zone
the area completely saturated with water
surface water
water that is on the Earth's surface, such as in a stream, river, lake, or reservoir.
spring
a water body formed when the side of a hill, a valley bottom or other excavation intersects a flowing body of groundwater at or below the local water table, below which the subsurface material is saturated with water.
water table
the top of the water surface in the saturated part of an aquifer.
withdrawal
water removed from a ground- or surface-water source for use.
well (water)--an artificial excavation put down by any method for the purposes of withdrawing water from the underground aquifers. A bored, drilled, or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids below ground.
Aeration Zone
The zone immediately below the land surface where the pores contain both water and air, but not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
An underground geological formation able to store and yield water.
Cone of Depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by the porosity and the water yield or pumping rate of the well.
Confining Layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movment is extremely slow.
Depletion
The loss of water from surface water reservoirs or groundwater aquifer at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
A lowering of the groundwater level caused by pumping.
Flow Rate
The time required for a volume of water to move between points. Typically groundwater moves very slowly- sometimes only inches per year.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground. Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Hydrologic Cycle
The paths water takes throungh its various states-- vapor, liquid, solid,-- as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Impermeable Layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Aeration zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
An underground geological formation able to store and yield water.
Cone of depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
Confining layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
A lowering of the groundwater level caused by pumping.
Flow rate
The time required for a volume of groundwater to move between
points. Typically groundwater moves very slowly—sometimes only inches per year.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Hydrologic cycle
(also known as the water cycle) The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration rate
The quantity of water that enters the soil surface in a specified time
interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Monitoring well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
Overwithdrawal
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Permeable/Permeability
Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil.
Permeable layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume
In groundwater a plume is an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated sand contains about 20% water; gravel, 25%; and clay, 48%.
Recharge
Water added to an aquifer. For example, when rainwater seeps into the ground. Recharge may occur artificially through injection wells or by spreading water over groundwater reservoirs.
Recharge rate
The quantity of water per unit of time that replenishes or refills an aquifer. Recharge zone or area: An area where permeable soil or rock allows water to seep into the
Remediation
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Residence time
Period of time that groundwater remains in an aquifer.
Safe yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." Also called sustainable yield.
Salt water intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
Saturation zone
The portion below the earth's surface that is saturated with water is called the zone of saturation. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
Subsidence
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the lnd. Subsidence is virtually an irreversible process.
Surface water
Water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Water table
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. The upper surface of the saturation zone.
Well
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
Well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well siting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead protection area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Withdrawal
Water removed from a surface or groundwater source for use.
Aeration zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
An underground geological formation able to store and yield water.
Cone of depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
Confining layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
A lowering of the groundwater level caused by pumping.
Flow rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes only inches per year.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Hydrologic cycle
(Also known as the water cycle) The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Monitoring well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
Overwithdrawal
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Permeable/Permeability
Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil.
Permeable layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume
In groundwater a plume is an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated sand contains about 20% water; gravel, 25%; and clay, 48%.
Recharge
Water added to an aquifer. For example, when rainwater seeps into the ground. Recharge may occur artificially through injection wells or by spreading water over groundwater reservoirs.
Recharge rate
The quantity of water per unit of time that replenishes or refills an aquifer.
Recharge zone or area
An area where permeable soil or rock allows water to seep into the ground to replenish an aquifer.
Remediation
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Residence time
Period of time that groundwater remains in an aquifer.
Safe yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." Also called sustainable yield.
Salt water intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
Saturation zone
The portion below the earth's surface that is saturated with water is called the zone of saturation. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
Subsidence
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the lnd. Subsidence is virtually an irreversible process.
Surface water
Water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Water table
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. The upper surface of the saturation zone.
Well
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
Well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well siting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead protection area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Withdrawal
Water removed from a surface or groundwater source for use.
Unconfined aquifer
An aquifer containing groundwater that is bellow porous materials such as soil, sand, and gravel.
Unsaturated zone
The zone immediately below the land surface where the pores contain both water and air, but are not completely saturated or soaked with water. Also referred to as the aeration zone or vadose zone.
Why close abandoned wells?
* To reduce the risk of groundwater contamination.
* To eliminate the risk of children, pets or livestock being injured by falling into the well.
Capillary Fringe
The capillary fringe is the subsurface layer in which groundwater seeps up from a water table by capillary action to fill pores.
Artesian Well
An artesian aquifer is a confined aquifer containing groundwater that will flow upward through a well, called an artesian well, without the need for pumping.
aeration zone
the zone immediately below the land , The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
aquifer
An underground formation that contains groundwater
cone of depression
the cone-shaped depression of the water table that occurs around a well
depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
confining layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
discharge
the volume of water flowing past a certain point in a given unit of time
drawdown
A lowering of the groundwater level caused by pumping.
flow rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes only inches per year.
groundwater
water that fills the cracks and spaces in underground soil and rock layers
hydrologic cycle
the natural process by which water is purified and made fresh through evaporation and precipitation. The cycle provides all the fresh water available for biological life.
impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
infiltration
the slow passage of a liquid through a filtering medium
infiltration rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
monitoring well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
overwithdrawal
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
permeable
that can be permeated; penetrable; porous; allowing liquids or gas to pass through; V. permeate: spread or flow throughout; charge
permeability
ability of rock or soil to allow water to flow through it
permeable layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
plume
area of moving groundwater that is contaminated with a pollutant
pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
porosity
Percentage of space in rock or soil occupied by voids, whether the voids are isolated or connected. Compare permeability.
recharge
NEW WATER that enters an aquifer from the surface
recharge rate
The quantity of water per unit of time that replenishes or refills an aquifer.
recharge zone
The ground surface where water enters an aquifer.
remediation
Process of cleaning up a contaminated site by physical, chemical or biological means. Typically applied to contaminated groundwater and soil.
residence time
Period of time that groundwater remains in an aquifer.
safe yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years."
salt water intrusion
near the coast, over-pumping of groundwater causes saltwater to move into the aquifer
saturation zone
The portion below the earth's surface that is saturated with water is called the zone of saturation. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
subsidence
a geological phenomenon in which ground in an area sinks
surface water
water contained in places such as lakes, ponds, rivers, streams, and reservoirs
water table
Upper surface of the zone of saturation, in which all available pores in the soil and rock in the earth's crust are filled with water.
well
a deep hole or shaft dug or drilled to obtain water or oil or gas or brine
well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
well siting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
wellhead protection area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
withdrawal
water removed from a surface or groundwater source for use
acequia
acequias are gravity-driven waterways, similar in concept to a flume. Most are simple ditches with dirt banks, but they can be lined with concrete. They were important forms of irrigation in the development of agriculture in the American Southwest. The proliferation of cotton, pecans and green chile as major agricultural staples owe their progress to the acequia system.
acid
a substance that has a pH of less than 7, which is neutral. Specifically, an acid has more free hydrogen ions (H+) than hydroxyl ions (OH-).
acre-foot (acre-ft)
the volume of water required to cover 1 acre of land (43,560 square feet) to a depth of 1 foot. Equal to 325,851 gallons or 1,233 cubic meters.
alkaline
sometimes water or soils contain an amount of alkali (strongly basic) substances sufficient to raise the pH value above 7.0 and be harmful to the growth of crops.
alkalinity
the capacity of water for neutralizing an acid solution.
alluvium
deposits of clay, silt, sand, gravel, or other particulate material that has been deposited by a stream or other body of running water in a streambed, on a flood plain, on a delta, or at the base of a mountain.
appropriation doctrine
the system for allocating water to private individuals used in most Western states. The doctrine of Prior Appropriation was in common use throughout the arid west as early settlers and miners began to develop the land. The prior appropriation doctrine is based on the concept of "First in Time, First in Right." The first person to take a quantity of water and put it to Beneficial Use has a higher priority of right than a subsequent user. Under drought conditions, higher priority users are satisfied before junior users receive water. Appropriative rights can be lost through nonuse; they can also be sold or transferred apart from the land. Contrasts with Riparian Water Rights.
aquaculture
farming of plants and animals that live in water, such as fish, shellfish, and algae.
aqueduct
a pipe, conduit, or channel designed to transport water from a remote source, usually by gravity.
aquifer
a geologic formation(s) that is water bearing. A geological formation or structure that stores and/or transmits water, such as to wells and springs. Use of the term is usually restricted to those water-bearing formations capable of yielding water in sufficient quantity to constitute a usable supply for people's uses.
aquifer (confined)
soil or rock below the land surface that is saturated with water. There are layers of impermeable material both above and below it and it is under pressure so that when the aquifer is penetrated by a well, the water will rise above the top of the aquifer.
aquifer (unconfined)
an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall.
artesian water
ground water that is under pressure when tapped by a well and is able to rise above the level at which it is first encountered. It may or may not flow out at ground level. The pressure in such an aquifer commonly is called artesian pressure, and the formation containing artesian water is an artesian aquifer or confined aquifer. See flowing well
artificial recharge
an process where water is put back into ground-water storage from surface-water supplies such as irrigation, or induced infiltration from streams or wells.
base flow
sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced streamflows. Natural base flow is sustained largely by ground-water discharges.
base
a substance that has a pH of more than 7, which is neutral. A base has less free hydrogen ions (H+) than hydroxyl ions (OH-).
bedrock
the solid rock beneath the soil and superficial rock. A general term for solid rock that lies beneath soil, loose sediments, or other unconsolidated material.
capillary action
actionthe means by which liquid moves through the porous spaces in a solid, such as soil, plant roots, and the capillary blood vessels in our bodies due to the forces of adhesion, cohesion, and surface tension. Capillary action is essential in carrying substances and nutrients from one place to another in plants and animals.
commercial water use
-water used for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions. Water for commercial uses comes both from public-supplied sources, such as a county water department, and self-supplied sources, such as local wells.
condensation
the process of water vapor in the air turning into liquid water. Water drops on the outside of a cold glass of water are condensed water. Condensation is the opposite process of evaporation.
consumptive use
that part of water withdrawn that is evaporated, transpired by plants, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. Also referred to as water consumed.
conveyance loss
water that is lost in transit from a pipe, canal, or ditch by leakage or evaporation. Generally, the water is not available for further use; however, leakage from an irrigation ditch, for example, may percolate to a ground-water source and be available for further use.
cubic feet per second (cfs)
a rate of the flow, in streams and rivers, for example. It is equal to a volume of water one foot high and one foot wide flowing a distance of one foot in one second. One "cfs" is equal to 7.48 gallons of water flowing each second. As an example, if your car's gas tank is 2 feet by 1 foot by 1 foot (2 cubic feet), then gas flowing at a rate of 1 cubic foot/second would fill the tank in two seconds.
desalination
the removal of salts from saline water to provide freshwater. This method is becoming a more popular way of providing freshwater to populations.
discharge
the volume of water that passes a given location within a given period of time. Usually expressed in cubic feet per second.
domestic water use
water used for household purposes, such as drinking, food preparation, bathing, washing clothes, dishes, and dogs, flushing toilets, and watering lawns and gardens. About 85% of domestic water is delivered to homes by a public-supply facility, such as a county water department. About 15% of the Nation's population supply their own water, mainly from wells.
drainage basin
land area where precipitation runs off into streams, rivers, lakes, and reservoirs. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large drainage basins, like the area that drains into the Mississippi River contain thousands of smaller drainage basins. Also called a "watershed."
drip irrigation
a common irrigation method where pipes or tubes filled with water slowly drip onto crops. Drip irrigation is a low-pressure method of irrigation and less water is lost to evaporation than high-pressure spray irrigation.
drawdown
a lowering of the ground-water surface caused by pumping.
effluent
water that flows from a sewage treatment plant after it has been treated.
erosion
the process in which a material is worn away by a stream of liquid (water) or air, often due to the presence of abrasive particles in the stream.
estuary
a place where fresh and salt water mix, such as a bay, salt marsh, or where a river enters an ocean.
evaporation
the process of liquid water becoming water vapor, including vaporization from water surfaces, land surfaces, and snow fields, but not from leaf surfaces. See transpiration
evapotranspiration
the sum of evaporation and transpiration.
flood
An overflow of water onto lands that are used or usable by man and not normally covered by water. Floods have two essential characteristics: The inundation of land is temporary; and the land is adjacent to and inundated by overflow from a river, stream, lake, or ocean.
flood, 100-year
A 100-year flood does not refer to a flood that occurs once every 100 years, but to a flood level with a 1 percent chance of being equaled or exceeded in any given year.
flood plain
a strip of relatively flat and normally dry land alongside a stream, river, or lake that is covered by water during a flood.
flood stage
The elevation at which overflow of the natural banks of a stream or body of water begins in the reach or area in which the elevation is measured.
flowing well/spring
a well or spring that taps ground water under pressure so that water rises without pumping. If the water rises above the surface, it is known as a flowing well.
freshwater, freshwater
water that contains less than 1,000 milligrams per liter (mg/L) of dissolved solids; generally, more than 500 mg/L of dissolved solids is undesirable for drinking and many industrial uses.
gage height
the height of the water surface above the gage datum (zero point). Gage height is often used interchangeably with the more general term, stage, although gage height is more appropriate when used with a gage reading.
gaging station
a site on a stream, lake, reservoir or other body of water where observations and hydrologic data are obtained. The U.S. Geological Survey measures stream discharge at gaging stations.
geyser
a geothermal feature of the Earth where there is an opening in the surface that contains superheated water that periodically erupts in a shower of water and steam.
giardiasis
a disease that results from an infection by the protozoan parasite Giardia Intestinalis, caused by drinking water that is either not filtered or not chlorinated. The disorder is more prevalent in children than in adults and is characterized by abdominal discomfort, nausea, and alternating constipation and diarrhea.
glacier
a huge mass of ice, formed on land by the compaction and recrystallization of snow, that moves very slowly downslope or outward due to its own weight.
greywater
wastewater from clothes washing machines, showers, bathtubs, hand washing, lavatories and sinks.
ground water
(1) water that flows or seeps downward and saturates soil or rock, supplying springs and wells. The upper surface of the saturate zone is called the water table. (2) Water stored underground in rock crevices and in the pores of geologic materials that make up the Earth's crust.
ground water, confined
ground water under pressure significantly greater than atmospheric, with its upper limit the bottom of a bed with hydraulic conductivity distinctly lower than that of the material in which the confined water occurs.
ground-water recharge
inflow of water to a ground-water reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge. Also, the volume of water added by this process.
ground water, unconfined
water in an aquifer that has a water table that is exposed to the atmosphere.
hardness
a water-quality indication of the concentration of alkaline salts in water, mainly calcium and magnesium. If the water you use is "hard" then more soap, detergent or shampoo is necessary to raise a lather.
headwater(s)
(1) the source and upper reaches of a stream; also the upper reaches of a reservoir. (2) the water upstream from a structure or point on a stream. (3) the small streams that come together to form a river. Also may be thought of as any and all parts of a river basin except the mainstream river and main tributaries.
hydroelectric power water use
the use of water in the generation of electricity at plants where the turbine generators are driven by falling water.
hydrologic cycle
the cyclic transfer of water vapor from the Earth's surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to earth, and through runoff into streams, rivers, and lakes, and ultimately into the oceans.
impermeable layer
a layer of solid material, such as rock or clay, which does not allow water to pass through.
industrial water use
water used for industrial purposes in such industries as steel, chemical, paper, and petroleum refining. Nationally, water for industrial uses comes mainly (80%) from self-supplied sources, such as a local wells or withdrawal points in a river, but some water comes from public-supplied sources, such as the county/city water department.
infiltration
flow of water from the land surface into the subsurface.
injection well
refers to a well constructed for the purpose of injecting treated wastewater directly into the ground. Wastewater is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. Injection wells are generally drilled into aquifers that don't deliver drinking water, unused aquifers, or below freshwater levels.
irrigation
the controlled application of water for agricultural purposes through manmade systems to supply water requirements not satisfied by rainfall. Here's a quick look at some types of irrigation systems.
irrigation water use
water application on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands, such as parks and golf courses.
kilogram
one thousand grams.
kilowatthour (KWH)
a power demand of 1,000 watts for one hour. Power company utility rates are typically expressed in cents per kilowatt-hour.
leaching
the process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water.
lentic waters
ponds or lakes (standing water).
levee
a natural or manmade earthen barrier along the edge of a stream, lake, or river. Land alongside rivers can be protected from flooding by levees.
livestock water use
water used for livestock watering, feed lots, dairy operations, fish farming, and other on-farm needs.
lotic waters
flowing waters, as in streams and rivers.
maximum contaminant level (MCL)
the designation given by the U.S. Environmental Protection Agency (EPA) to water-quality standards promulgated under the Safe Drinking Water Act. The MCL is the greatest amount of a contaminant that can be present in drinking water without causing a risk to human health.
milligram (mg)
One-thousandth of a gram.
milligrams per liter (mg/l)
a unit of the concentration of a constituent in water or wastewater. It represents 0.001 gram of a constituent in 1 liter of water. It is approximately equal to one part per million (PPM).
million gallons per day (Mgd)
a rate of flow of water equal to 133,680.56 cubic feet per day, or 1.5472 cubic feet per second, or 3.0689 acre-feet per day. A flow of one million gallons per day for one year equals 1,120 acre-feet (365 million gallons).
mining water use
water use during quarrying rocks and extracting minerals from the land.
municipal water system
a water system that has at least five service connections or which regularly serves 25 individuals for 60 days; also called a public water system
nephelometric turbidity unit (NTU)
unit of measure for the turbidity of water. Essentially, a measure of the cloudiness of water as measured by a nephelometer. Turbidity is based on the amount of light that is reflected off particles in the water.
NGVD
National Geodetic Vertical Datum. (1) As corrected in 1929, a vertical control measure used as a reference for establishing varying elevations. (2) Elevation datum plane previously used by the Federal Emergency Management Agency (FEMA) for the determination of flood elevations. FEMA current uses the North American Vertical Datum Plane.
NGVD of 1929
National Geodetic Vertical Datum of 1929. A geodetic datum derived from a general adjustment of the first order level nets of the United States and Canada. It was formerly called "Sea Level Datum of 1929" or "mean sea level" in the USGS series of reports. Although the datum was derived from the average sea level over a period of many years at 26 tide stations along the Atlantic, Gulf of Mexico, and Pacific Coasts, it does not necessarily represent local mean sea level at any particular place.
non-point source (NPS) pollution
pollution discharged over a wide land area, not from one specific location. These are forms of diffuse pollution caused by sediment, nutrients, organic and toxic substances originating from land-use activities, which are carried to lakes and streams by surface runoff. Non-point source pollution is contamination that occurs when rainwater, snowmelt, or irrigation washes off plowed fields, city streets, or suburban backyards. As this runoff moves across the land surface, it picks up soil particles and pollutants, such as nutrients and pesticides.
organic matter
plant and animal residues, or substances made by living organisms. All are based upon carbon compounds.
osmosis
the movement of water molecules through a thin membrane. The osmosis process occurs in our bodies and is also one method of desalinating saline water.
outfall
the place where a sewer, drain, or stream discharges; the outlet or structure through which reclaimed water or treated effluent is finally discharged to a receiving water body.
oxygen demand
the need for molecular oxygen to meet the needs of biological and chemical processes in water. Even though very little oxygen will dissolve in water, it is extremely important in biological and chemical processes.
pH
a measure of the relative acidity or alkalinity of water. Water with a pH of 7 is neutral; lower pH levels indicate increasing acidity, while pH levels higher than 7 indicate increasingly basic solutions.
particle size
the diameter, in millimeters, of suspended sediment or bed material.
Particle-size classifications are:
[1] Clay—0.00024-0.004 millimeters (mm);
[2] Silt—0.004-0.062 mm;
[3] Sand—0.062-2.0 mm; and
[4] Gravel—2.0-64.0 mm.
parts per billion
the number of "parts" by weight of a substance per billion parts of water. Used to measure extremely small concentrations.
parts per million
the number of "parts" by weight of a substance per million parts of water. This unit is commonly used to represent pollutant concentrations.
pathogen
a disease-producing agent; usually applied to a living organism. Generally, any viruses, bacteria, or fungi that cause disease.
peak flow
the maximum instantaneous discharge of a stream or river at a given location. It usually occurs at or near the time of maximum stage.
per capita use
the average amount of water used per person during a standard time period, generally per day.
percolation
(1) The movement of water through the openings in rock or soil. (2) the entrance of a portion of the streamflow into the channel materials to contribute to ground water replenishment.
permeability
the ability of a material to allow the passage of a liquid, such as water through rocks. Permeable materials, such as gravel and sand, allow water to move quickly through them, whereas unpermeable material, such as clay, don't allow water to flow freely.
point-source pollution
water pollution coming from a single point, such as a sewage-outflow pipe.
polychlorinated biphenyls (PCBs)
a group of synthetic, toxic industrial chemical compounds once used in making paint and electrical transformers, which are chemically inert and not biodegradable. PCBs were frequently found in industrial wastes, and subsequently found their way into surface and ground waters. As a result of their persistence, they tend to accumulate in the environment. In terms of streams and rivers, PCBs are drawn to sediment, to which they attach and can remain virtually indefinitely. Although virtually banned in 1979 with the passage of the Toxic Substances Control Act, they continue to appear in the flesh of fish and other animals.
porosity
a measure of the water-bearing capacity of subsurface rock. With respect to water movement, it is not just the total magnitude of porosity that is important, but the size of the voids and the extent to which they are interconnected, as the pores in a formation may be open, or interconnected, or closed and isolated. For example, clay may have a very high porosity with respect to potential water content, but it constitutes a poor medium as an aquifer because the pores are usually so small.
potable water
water of a quality suitable for drinking.
precipitation
rain, snow, hail, sleet, dew, and frost.
primary wastewater treatment
the first stage of the wastewater-treatment process where mechanical methods, such as filters and scrapers, are used to remove pollutants. Solid material in sewage also settles out in this process.
prior appropriation doctrine
the system for allocating water to private individuals used in most Western states. The doctrine of Prior Appropriation was in common use throughout the arid West as early settlers and miners began to develop the land. The prior appropriation doctrine is based on the concept of "First in Time, First in Right." The first person to take a quantity of water and put it to beneficial use has a higher priority of right than a subsequent user. The rights can be lost through nonuse; they can also be sold or transferred apart from the land. Contrasts with riparian water rights.
public supply
water withdrawn by public governments and agencies, such as a county water department, and by private companies that is then delivered to users. Public suppliers provide water for domestic, commercial, thermoelectric power, industrial, and public water users. Most people's household water is delivered by a public water supplier. The systems have at least 15 service connections (such as households, businesses, or schools) or regularly serve at least 25 individuals daily for at least 60 days out of the year.
public water use
water supplied from a public-water supply and used for such purposes as firefighting, street washing, and municipal parks and swimming pools.
rating curve
A drawn curve showing the relation between gage height and discharge of a stream at a given gaging station.
recharge
water added to an aquifer. For instance, rainfall that seeps into the ground.
reclaimed wastewater
treated wastewater that can be used for beneficial purposes, such as irrigating certain plants.
recycled water
water that is used more than one time before it passes back into the natural hydrologic system.
reservoir
a pond, lake, or basin, either natural or artificial, for the storage, regulation, and control of water.
return flow
(1) That part of a diverted flow that is not consumptively used and returned to its original source or another body of water. (2) (Irrigation) Drainage water from irrigated farmlands that re-enters the water system to be used further downstream.
return flow (irrigation)
irrigation water that is applied to an area and which is not consumed in evaporation or transpiration and returns to a surface stream or aquifer.
reverse osmosis
(1) (Desalination) The process of removing salts from water using a membrane. With reverse osmosis, the product water passes through a fine membrane that the salts are unable to pass through, while the salt waste (brine) is removed and disposed. This process differs from electrodialysis, where the salts are extracted from the feedwater by using a membrane with an electrical current to separate the ions. The positive ions go through one membrane, while the negative ions flow through a different membrane, leaving the end product of freshwater. (2) (Water Quality) An advanced method of water or wastewater treatment that relies on a semi-permeable membrane to separate waters from pollutants. An external force is used to reverse the normal osmotic process resulting in the solvent moving from a solution of higher concentration to one of lower concentration.
riparian water rights
the rights of an owner whose land abuts water. They differ from state to state and often depend on whether the water is a river, lake, or ocean. The doctrine of riparian rights is an old one, having its origins in English common law. Specifically, persons who own land adjacent to a stream have the right to make reasonable use of the stream. Riparian users of a stream share the streamflow among themselves, and the concept of priority of use (Prior Appropriation Doctrine) is not applicable. Riparian rights cannot be sold or transferred for use on nonriparian land.
river
A natural stream of water of considerable volume, larger than a brook or creek.
runoff
(1) That part of the precipitation, snow melt, or irrigation water that appears in uncontrolled surface streams, rivers, drains or sewers. Runoff may be classified according to speed of appearance after rainfall or melting snow as direct runoff or base runoff, and according to source as surface runoff, storm interflow, or ground-water runoff. (2) The total discharge described in (1), above, during a specified period of time. (3) Also defined as the depth to which a drainage area would be covered if all of the runoff for a given period of time were uniformly distributed over it.
saline water
water that contains significant amounts of dissolved solids.
Here are our parameters for saline water:
Fresh water - Less than 1,000 parts per million (ppm)
Slightly saline water - From 1,000 ppm to 3,000 ppm
Moderately saline water - From 3,000 ppm to 10,000 ppm
Highly saline water - From 10,000 ppm to 35,000 ppm
secondary wastewater treatment
treatment (following primary wastewater treatment) involving the biological process of reducing suspended, colloidal, and dissolved organic matter in effluent from primary treatment systems and which generally removes 80 to 95 percent of the Biochemical Oxygen Demand (BOD) and suspended matter. Secondary wastewater treatment may be accomplished by biological or chemical-physical methods. Activated sludge and trickling filters are two of the most common means of secondary treatment. It is accomplished by bringing together waste, bacteria, and oxygen in trickling filters or in the activated sludge process. This treatment removes floating and settleable solids and about 90 percent of the oxygen-demanding substances and suspended solids. Disinfection is the final stage of secondary treatment.
sediment
usually applied to material in suspension in water or recently deposited from suspension. In the plural the word is applied to all kinds of deposits from the waters of streams, lakes, or seas.
sedimentary rock
rock formed of sediment, and specifically: (1) sandstone and shale, formed of fragments of other rock transported from their sources and deposited in water; and (2) rocks formed by or from secretions of organisms, such as most limestone. Many sedimentary rocks show distinct layering, which is the result of different types of sediment being deposited in succession.
sedimentation tanks
wastewater tanks in which floating wastes are skimmed off and settled solids are removed for disposal.
self-supplied water
water withdrawn from a surface- or ground-water source by a user rather than being obtained from a public supply. An example would be homeowners getting their water from their own well.
seepage
(1) The slow movement of water through small cracks, pores, Interstices, etc., of a material into or out of a body of surface or subsurface water. (2) The loss of water by infiltration into the soil from a canal, ditches, laterals, watercourse, reservoir, storage facilities, or other body of water, or from a field.
septic tank
a tank used to detain domestic wastes to allow the settling of solids prior to distribution to a leach field for soil absorption. Septic tanks are used when a sewer line is not available to carry them to a treatment plant. A settling tank in which settled sludge is in immediate contact with sewage flowing through the tank, and wherein solids are decomposed by anaerobic bacterial action.
settling pond (water quality)
an open lagoon into which wastewater contaminated with solid pollutants is placed and allowed to stand. The solid pollutants suspended in the water sink to the bottom of the lagoon and the liquid is allowed to overflow out of the enclosure.
sewage treatment plant
a facility designed to receive the wastewater from domestic sources and to remove materials that damage water quality and threaten public health and safety when discharged into receiving streams or bodies of water. The substances removed are classified into four basic areas:
[1] greases and fats;
[2] solids from human waste and other sources;
[3] dissolved pollutants from human waste and decomposition products; and
[4] dangerous microorganisms.
Most facilities employ a combination of mechanical removal steps and bacterial decomposition to achieve the desired results. Chlorine is often added to discharges from the plants to reduce the danger of spreading disease by the release of pathogenic bacteria.
sewer
a system of underground pipes that collect and deliver wastewater to treatment facilities or streams.
sinkhole
a depression in the Earth's surface caused by dissolving of underlying limestone, salt, or gypsum. Drainage is provided through underground channels that may be enlarged by the collapse of a cavern roof.
solute
a substance that is dissolved in another substance, thus forming a solution.
solution
a mixture of a solvent and a solute. In some solutions, such as sugar water, the substances mix so thoroughly that the solute cannot be seen. But in other solutions, such as water mixed with dye, the solution is visibly changed.
solvent
a substance that dissolves other substances, thus forming a solution. Water dissolves more substances than any other, and is known as the "universal solvent".
specific conductance
a measure of the ability of water to conduct an electrical current as measured using a 1-cm cell and expressed in units of electrical conductance, i.e., Siemens per centimeter at 25 degrees Celsius. Specific conductance can be used for approximating the total dissolved solids content of water by testing its capacity to carry an electrical current. In water quality, specific conductance is used in ground water monitoring as an indication of the presence of ions of chemical substances that may have been released by a leaking landfill or other waste storage or disposal facility. A higher specific conductance in water drawn from downgradient wells when compared to upgradient wells indicates possible contamination from the facility.
spray irrigation
an common irrigation method where water is shot from high-pressure sprayers onto crops. Because water is shot high into the air onto crops, some water is lost to evaporation.
spring
a water body formed when the side of a hill, a valley bottom or other excavation intersects a flowing body of groundwater at or below the local water table, below which the subsurface material is saturated with water.
storm sewer
a sewer that carries only surface runoff, street wash, and snow melt from the land. In a separate sewer system, storm sewers are completely separate from those that carry domestic and commercial wastewater (sanitary sewers).
stream
a general term for a body of flowing water; natural water course containing water at least part of the year. In hydrology, it is generally applied to the water flowing in a natural channel as distinct from a canal.
streamflow
the water discharge that occurs in a natural channel. A more general term than runoff, streamflow may be applied to discharge whether or not it is affected by diversion or regulation.
subsidence
a dropping of the land surface as a result of ground water being pumped. Cracks and fissures can appear in the land. Subsidence is virtually an irreversible process.
surface tension
the attraction of molecules to each other on a liquid's surface. Thus, a barrier is created between the air and the liquid.
surface water
water that is on the Earth's surface, such as in a stream, river, lake, or reservoir.
suspended sediment
very fine soil particles that remain in suspension in water for a considerable period of time without contact with the bottom. Such material remains in suspension due to the upward components of turbulence and currents and/or by suspension.
suspended-sediment concentration
the ratio of the mass of dry sediment in a water-sediment mixture to the mass of the water-sediment mixture. Typically expressed in milligrams of dry sediment per liter of water-sediment mixture.
suspended-sediment discharge
the quantity of suspended sediment passing a point in a stream over a specified period of time. When expressed in tons per day, it is computed by multiplying water discharge (in cubic feet per second) by the suspended-sediment concentration (in milligrams per liter) and by the factor 0.0027.
suspended solids
solids that are not in true solution and that can be removed by filtration. Such suspended solids usually contribute directly to turbidity. Defined in waste management, these are small particles of solid pollutants that resist separation by conventional methods.
tertiary wastewater treatment
selected biological, physical, and chemical separation processes to remove organic and inorganic substances that resist conventional treatment practices; the additional treatment of effluent beyond that of primary and secondary treatment methods to obtain a very high quality of effluent. The complete wastewater treatment process typically involves a three-phase process: (1) First, in the primary wastewater treatment process, which incorporates physical aspects, untreated water is passed through a series of screens to remove solid wastes; (2) Second, in the secondary wastewater treatment process, typically involving biological and chemical processes, screened wastewater is then passed a series of holding and aeration tanks and ponds; and (3) Third, the tertiary wastewater treatment process consists of flocculation basins, clarifiers, filters, and chlorine basins or ozone or ultraviolet radiation processes.
thermal pollution
a reduction in water quality caused by increasing its temperature, often due to disposal of waste heat from industrial or power generation processes. Thermally polluted water can harm the environment because plants and animals can have a hard time adapting to it.
thermoelectric power water use
water used in the process of the generation of thermoelectric power. Power plants that burn coal and oil are examples of thermoelectric-power facilities.
transmissibility (ground water)
the capacity of a rock to transmit water under pressure. The coefficient of transmissibility is the rate of flow of water, at the prevailing water temperature, in gallons per day, through a vertical strip of the aquifer one foot wide, extending the full saturated height of the aquifer under a hydraulic gradient of 100-percent. A hydraulic gradient of 100-percent means a one foot drop in head in one foot of flow distance.
transpiration
process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, such as leaf pores. See evapotranspiration.
Tributary
a smaller river or stream that flows into a larger river or stream. Usually, a number of smaller tributaries merge to form a river.
turbidity
the amount of solid particles that are suspended in water and that cause light rays shining through the water to scatter. Thus, turbidity makes the water cloudy or even opaque in extreme cases. Turbidity is measured in nephelometric turbidity units (NTU).
unsaturated zone
the zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. These zones differ from an aquifer, where the pores are saturated with water.
wastewater
water that has been used in homes, industries, and businesses that is not for reuse unless it is treated.
wastewater-treatment return flow
water returned to the environment by wastewater-treatment facilities.
water cycle
the circuit of water movement from the oceans to the atmosphere and to the Earth and return to the atmosphere through various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transportation.
water quality
a term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose.
water table
the top of the water surface in the saturated part of an aquifer.
water use
water that is used for a specific purpose, such as for domestic use, irrigation, or industrial processing. Water use pertains to human's interaction with and influence on the hydrologic cycle, and includes elements, such as water withdrawal from surface- and ground-water sources, water delivery to homes and businesses, consumptive use of water, water released from wastewater-treatment plants, water returned to the environment, and instream uses, such as using water to produce hydroelectric power.
watershed
the land area that drains water to a particular stream, river, or lake. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large watersheds, like the Mississippi River basin contain thousands of smaller watersheds.
watthour (Wh)
an electrical energy unit of measure equal to one watt of power supplied to, or taken from, an electrical circuit steadily for one hour.
well (water)
an artificial excavation put down by any method for the purposes of withdrawing water from the underground aquifers. A bored, drilled, or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids below ground.
withdrawal
water removed from a ground- or surface-water source for use.
xeriscaping
a method of landscaping that uses plants that are well adapted to the local area and are drought-resistant. Xeriscaping is becoming more popular as a way of saving water at home.
yield
mass per unit time per unit area
Aeration Zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
An underground geological formation able to store and yield water.
Cone of Depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
Confining Layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Depletion
The loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
A lowering of the groundwater level caused by pumping.
Flow Rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly—sometimes only inches per year.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops.
Hydrologic Cycle
(also known as the water cycle) The paths water takes through its various states--vapor, liquid, solid--as it moves throughout the oceans, atmosphere, groundwater, streams, etc.
Impermeable Layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration Rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Monitoring Well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
Over withdrawl
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Permeable
Capable of transmitting water (porous rock, sediment, or soil)
Permeability
the rate at which water moves through rocks or soil.
Permeable Layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume
In groundwater a plume is an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Pore Space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated sand contains about 20% water; gravel, 25%; and clay, 48%.
Recharge
Water added to an aquifer. For example, when rainwater seeps into the ground. Recharge may occur artificially through injection wells or by spreading water over groundwater reservoirs.
Recharge Rate
The quantity of water per unit of time that replenishes or refills an aquifer.
Recharge Zone of Area
An area where permeable soil or rock allows water to seep into the ground to replenish an aquifer.
Remediation
Containment, treatment or removal of contaminated groundwater. May also include containment, treatment or removal of contaminated soil above the water table.
Residence Time
Period of time that groundwater remains in an aquifer.
Safe Yield
The annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." Also called sustainable yield.
Salt Water Intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water encroaching into fresh water supply.
Saturation Zone
The portion below the earth's surface that is saturated with water is called the zone of saturation. The upper surface of this zone, open to atmospheric pressure, is known as the water table.
Subsidence
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the land. Subsidence is virtually an irreversible process.
Surface Water
Water above the surface of the land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Water Table
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. The upper surface of the saturation zone.
Well
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water.
Well Closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well Sitting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead Protection Area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Withdrawl
Water removed from a surface or groundwater source for use.
Aeration zone
The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
Aquifer
An underground geological formation able to store and yield water.
Bedrock
Solid rock beneath the soil
Cone of depression
The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
Confining layer
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Depletion
The loss of water from surface wafer reservoirs or groundwater aquifers at a rate greater than that of recharge.
Discharge
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
Drawdown
A lowering of the groundwater level caused by pumping.
Flow rate
The time required for a volume of groundwater to move between points. Typically groundwater moves very slowly-sometimes only inches per year.
Groundwater
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone). It is a natural resource that is used for drinking, recreation, industry, and growing crops.
Hydrologic cycle
The paths water takes through its various states- vapor, liquid, solid- as it moves throughout the oceans, atmosphere, groundwater, streams, etc. Also known as the water cycle
Impermeable layer
A layer of material (such as clay) in an aquifer through which water does not pass.
Infiltration
Flow of water from the land surface into the subsurface.
Infiltration rate
The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time.
Monitoring well
A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality.
Overwithdrawal
Withdrawal of groundwater over a period of time that exceeds the recharge rate of the supply aquifer. Also referred to as overdraft or mining the aquifer.
Permeable/Permeability
Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil.
Permeable layer
A layer of porous material (rock, soil, unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the ground.
Plume
In groundwater, it is an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The source site has the highest concentration, and the concentration decreases away from the source.
Pore space
Openings between geologic material found underground. Also referred to as void space or interstices.
Porosity
The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. (example: saturated sand contains about 20% water; gravel, 25%; and clay, 48%.)
Recharge
Water added to an aquifer. (example: when rain wafer seeps into the ground.) It may occur artificially through injection wells or by spreading water over groundwater reservoirs.
Recharge rate
The quantity of water per unit of time that replenishes or refills an aquifer.
Recharge zone or area
An area where permeable soil or rock allows water to deep into the ground to replenish an aquifer.
Remediation
Containment, treatment, or removal of contaminated groundwater. May also include containment, treatment, or removal of contaminated soil above the water table.
Residence time
Period of time that groundwater remains in an aquifer.
Safe yield
The annual amount of wafer that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." Also called sustainable yield.
Salt water intrusion
Process by which an aquifer is overdrafted creating a flow imbalance within an area that results in salt water enroaching into fresh water supply.
Saturation zone
The portion below the earth's surface that is saturated with water.
Subsidence
A depression of the land surface as a result of groundwater being pumped. Cracks and fissures can appear in the land. It is virtually an irreversible process.
Surface water
Water above the surface of land, including lakes, rivers, streams, ponds, floodwater, and runoff.
Water table
The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. It is the upper surface of the saturation zone where it is open to atmospheric pressure.
Well
A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract, or monitor water.
Well closure
The process of sealing a well that is no longer being used to prevent groundwater contamination and harm to people and animals.
Well sitting
Location of a well placed to best protect water quality, access adequate water quantity, and allow for inspection and maintenance of the well.
Wellhead protection area
A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
Withdrawal
Water removed from a surface or groundwater source for use.
Artificial Recharge
Putting water back into groundwater storage from surface water supplies such as irrigation, or induced infiltration from streams or wells.
Temporary Wetland
A type of wetland in which water is present for only part of the year, usually during wet or rainy seasons; also known as vernal pools.
Strata
A layer within the earth's crust that generally consists of the same kinds of soils or rock material
Ridge Lines
Points of higher ground that separate two adjacent streams or watersheds; also known as divides.
Potentiometric Surface
The potential level to which water will rise above the water level in an aquifer in a well that penetrates a confined aquifer
Brackish
Mixed fresh and salt water