Entire Glossary
Saturate your vocabulary with some commonly used water terms.

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absorb—to take in.

acid—A substance having a pH less than l.0. Liquids are sour and corrosive.

acid rain—Rain with a pH of less than 5.6; results from atmospheric moisture mixing with sulphur and nitrogen oxides emitted from burning fossil fuels or from volcanic activity.

activated sludge—sludge particles produced by the growth of microorganisms in aerated tanks as a part of the process to treat wastewater.

acre-foot—a volume of water equal to the amount that would cover 1 acre to a depth of 1 foot, or 325,829 gallons. An acre-foot of water is enough for a family of five for 1 year.

aeration—the addition of air to water. It lets gases trapped in the water escape and adds oxygen to the water, as in the first step of drinking water treatment.

aerobic—with oxygen; needing oxygen for cellular respiration.

Alfred Merritt Smith Water Treatment Facility (AMSWTF)—The Southern Nevada Water System's water treatment facility located near Saddle Island on the shore of Lake Mead. First put into operation in 1971, the AMSWTF treats and transmits Colorado River water to the Las Vegas Valley.

algal bloom—a sudden increase in the amount of algae, usually causing large floating masses to form. Algal bloom can affect water quality by lowering dissolving oxygen (DO) content and decreasing sunlight penetration. The blooms are usually caused by excessive nutrient addition and can be characteristic of a eutrophic lake.

alkaline—Having a pH greater than 7.0. Liquids are caustic and bitter.

alluvial—an adjective referring to the process of depositing soil or earth material by running water, as in a riverbed, flood plain or delta.

alum—aluminum salt used as flocculating agent.

anaerobic—in the absence of oxygen; able to live and grow where there is no air or free oxygen, as certain bacteria.

aquatic—living or growing in or on water.

aqueduct—a pipe or conduit made for conveying water.

aquifer—a layer of underground sand, gravel or porous rock through which water flows slowly. Use of the term is usually restricted to those water-bearing structures capable of yielding water in sufficient quantity to constitute a usable supply.

aquifer confined—an aquifer which is bounded above and below by formations of impermeable or relatively impermeable material.

aquifer recharge—the addition of water by any means to an aquifer.

artesian aquifer—an aquifer that is sandwiched between two layers of impermeable materials and is under great pressure, forcing the water to rise without pumping. Springs often surface from artesian aquifers.

artesian well—a well that taps a confined aquifer where the water in the aquifer is under sufficient pressure to force the water to the surface.

artesian zone—a zone where water is confined in an aquifer under pressure so the water will rise in a well casing or drilled hole above the bottom of the confining layer overlying the aquifer.

artificial groundwater recharge—The process of injecting treated water through a well into the groundwater. Artificially recharged groundwater is measured and recorded as banked groundwater recharge, which can be recovered at a later time.

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banked groundwater recharge—water that has been stored temporarily in the groundwater aquifer through a program of artificial groundwater recharge.

bicarbonate—an acid salt of carbonic acid.

bioaccumlation—the process by which a substance is taken up by an aquatic organism both from water and through food.

biochemical oxygen demand (BOD)—used to describe the amount of oxygen that will be consumed by microorganisms during the biological reaction of oxygen with organic materials.

biomagnification—bio-accumlation occurring through several levels of a food chain; process by which certain substances (such as pesticides or heavy metals) are deposited into a waterway, are eaten by aquatic organisms, which are in turn eaten by large birds, animals or humans, causing the substances to become increasingly concentrated in tissues or organs as they move up the food chain.

bio remediation—a biologically mediated corrective process that occurs naturally over time; humans may speed up this process through technology.

bio solids—sludge that is intended for beneficial use. Bio solids must meet certain government-specified standards depending on use as a fertilizer or as a soil additive.

brackish water—a mixture of salt and fresh water, usually found where rivers enter the ocean.

buoyancy—the ability of water to support weight and the degree to which it can support weight.

calcium carbonate—one of the most stable, common and widely-dispersed materials on Earth; occurs naturally in oyster & clam shells, calcite, limestone, marble, chalk, and other forms; used to express hardness and alkalinity of water.

capillary action—action by which the surface of a liquid in contact with a solid is elevated or depressed depending upon the attraction of the liquid's molecules for each other and for those of the solid (example: water in a capillary tube).

carbon dioxide—colorless, odorless gas made of carbon and oxygen; exhaled by animals and humans, utilized by plants in photosynthesis.

carbonic acid—substance formed by combining water and the carbon dioxide.

career—a chosen pursuit of life's work; a job or profession one is trained to do.

change of state—change of matter from one state (gas, liquid, solid) to another.

channel—a natural or artificial course for running water.

chemical—a substance, like chlorine, used to kill bacteria in the water.

chlorination—the addition of chlorine to water to destroy microorganisms.

chlorine—a chemical used to clean water.

chronic effects—adverse health effects that are the result of long-term exposure or those that are permanent or long-lasting.

clarifier—a vessel in which solids settle out of water by gravity during drinking water treatment processes.

Clark County Department of Comprehensive Planning—The department of the Clark County government responsible for coordinating certain planning activities for the county, including responsibility for the regional wastewater management plan.

coagulation—dirt and other solid particles are stuck together with chemicals so that they can be removed from the water.

Colorado River Commission (CRC)—The Colorado River Commission represents the State of Nevada at all federal, interstate and international discussions regarding the management and operations of the Colorado River.

condensation—the changing of a gas or vapor into a liquid.

conservation—act of using a resource only when needed for the purpose of protecting from waste of loss of the resource.

conserve—save, protect, keep; to use a resource wisely and efficiently.

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dehydrate—to take away water.

density—the ratio of an object's mass to its volume.

desalinization—the process of salt removal from sea or brackish water.

desert—an area of land with very little precipitation (rain or snow).

dilution—the process of adding a known amount of a solvent (usually water) to another solution to make it less concentrated.

disinfection—the final step at a water treatment plant; disinfection kills any organism that may be harmful.

dissolved oxygen (DO)—oxygen gas dissolved in water.

distilled water—water that has undergone the process of evaporation and condensation and has had the minerals removed.

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. Also called a "watershed."

drip irrigation—above ground, low-pressure watering system with flexible tubing that releases small, steady amounts of water through emitters placed near individual plants.

drought—a prolonged period of dry weather; a lack of rain; nature's failure to fulfill the water wants and needs of man.

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ecosystem—the relationship between all the parts (living and nonliving) within an environmental community.

effluent—water that flows from a wastewater treatment process.

environment—surroundings.

Environmental Impact Statement (EIS)—a detailed written statement, required by Section 102(2)(c) of the National Environmental Policy Act. Analyzes the environmental impacts of a proposed action, adverse effects that cannot be avoided, alternative courses of action, short-term uses of the environment versus the maintenance of enhancement of long-term productivity, and any irreversible and irretrievable commitment of resources.

erosion—the wearing away of land surface by wind, water, ice or other geologic agents. This occurs naturally from weather or runoff but is often intensified by human land use practices.

estuary—an area where fresh water meets salt water, such as with bays, mouths of rivers, salt marshes and lagoons.

eutrophic—refers to a body of water characterized by nutrient-rich water supporting abundant growth of algae and/or other aquatic plants.

eutrophication—see eutrophic; the natural aging cycle of lakes, normally taking centuries to accomplish, but can be accelerated when outside sources of nutrients are added such as wastewater, fertilizer or feed lot runoff.

evaporate—to convert or change into a vapor.

evaporation—the change of matter from liquid to the gaseous or vaporous state; the process by which water becomes a vapor at a temperature below the boiling point.

faucet—a device (that can be controlled to stop the flow of water) through which water flows into a sink or other basin.

fecal coliform bacteria—a type of coliform bacteria found in the intestines of humans and other warm-blooded animals that aids in the digestion process. It is used as an indicator of fecal contamination and the possible presence of pathogens.

feed lots—confined areas where many livestock may be kept.

filtration—a process that removes most of the solid impurities remaining in water after coagulation and sedimentation have taken place.

filter—something that helps separate out unwanted things from water.

flow—move smoothly.

forebay—a storage tank or small reservoir constructed specifically to establish a stable operating supply of water for the intake of a pumping station.

fresh water—inland water that has a low concentration of minerals, salts and dissolved solids (below 0.01 percent).

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Geographic Information System (GIS)—a geographically referenced database that connects information about things to locations, which can be referenced by any convenient system such as latitude and longitude or three-dimensional coordinates.

Global Positioning System (GPS)—a system that establishes the precise location of a radio-based computer receiving signals from orbiting space satellites, possibly in combination with the use of a transmitter and a local base station.

gravity—the gravitational attraction of the earth's mass for bodies at or near its surface.

greywater—untreated water after it has been used for showering, bathing, clothes washing, hand washing and faucet uses. Water contaminated by human or animal wastes or by chemicals is not considered greywater.

groundwater—the supply of fresh water found beneath the Earth's surface (usually in aquifers), often used for supplying wells and springs.

groundwater recharge recovery—the withdrawal of banked groundwater recharge for use as a part of the water supply.

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hardness—that characteristic of water caused by calcium and magnesium that causes scaling, spots on glassware and other aesthetic concerns. Colorado River water in Lake Mead is considered to be very hard, having a calcium carbonate value of about 300 milligrams per liter.

hardwater—water that contains minerals, especially calcium and magnesium ions, that cause soap to precipitate producing a scum or scale in boilers.

hydroelectric—having to do with the production of electricity by waterpower.

hydrogeology —the science dealing with the occurrence, distribution and movement of water below the surface of the Earth with a greater emphasis on geology.

hydrologic cycle—the process of water's movement form the atmosphere to the land or ocean and back into the atmosphere using the processes of precipitation, condensation, evaporation and transpiration.

hydrologist—a person who applies scientific knowledge and mathematical principles to solve water-related problems in society, such as problems of quantity, quality and availability.

hydrology—the study of water, its properties, its distribution on Earth and its effects on the Earth's environment.

infiltration—the gradual downward flow of water from the surface into soil material.

impermeable layer —a layer of solid material, such as rock or clay, which does not allow water to pass through.

influent—wastewater flowing into a wastewater treatment facility.

intake—the first point of entry for water flowing into a process or system. The Southern Nevada Water System's two primary water intakes are located at Saddle Island, more than 100 feet beneath the surface of Lake Mead.

intake system—the collection of integrated components that transmit water to the Southern Nevada Water System. The intake system may consist of an intake structure, tunnel, pumping equipment, metering equipment and piping.

ion—an atom or molecule that has lost or gained one or more electrons.

irrigation—a system of pipes or canals used to bring water to places where it is needed.

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lake—a large standing body of water surrounded by land.

Lake Mead—one of the largest artificial lakes in the world (115 miles long), created when Hoover Dam was built on the Colorado River.

lateral—a distinct branch of the transmission facility serving a particular turnout or small group of turnouts.

Las Vegas Valley—the topographic basin containing the City of Las Vegas, the City of North Las Vegas, the City of Henderson and certain unincorporated townships of Clark County.

Las Vegas Valley Water District (LVVWD)—a water purveyor that serves approximately 800,000 people in Southern Nevada, including the City of Las Vegas and other unincorporated areas within Clark County. LVVWD is a member of the Southern Nevada Water Authority and the authorized operating agency for SNWA affairs and the Southern Nevada Water System.

Las Vegas Wash—the primary drainage channel for the Las Vegas Valley Hydrographic Basin. Originating from a series of ephemeral creeks, desert washes and runoff channels in the far northern and western parts of the hydrographic basin, the wash takes shape in the eastern and southeastern metropolitan Las Vegas Valley, tracing a 12-mile-long curve that ends at Las Vegas Bay in Lake Mead.

lea——to pass through a small hole or crack.

leaching—the removal of water action of chemical elements and compounds from rocks and soil.

liquid—fluid matter that takes the shape of its container.

liter—1,000 milliliters.

mineral water—water that contains minerals.

municipal water—municipal water may come from either groundwater or surface water sources. Once water has entered a municipal water system, from any source, it is considered municipal water.

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natural recharge—the replenishment of a groundwater source from natural water supplies such as precipitation and stream flows.

natural resources—sources of supply for earth materials.

Nevada Department of Environmental Protection (NDEP)—the state agency responsible for overseeing air and water quality regulations and the primary agency for enforcing compliance with the federal Clean Water Act and Clean Air Act.

nitrates—compounds containing nitrogen as nitrates; found in animal wastes, fertilizers and septic tanks or untreated wastewater.

non-point source pollution—pollution that cannot be traced to a specific location. Non-point source pollution occurs when rainwater, snowmelt or irrigation washes off plowed fields, city streets or urban backyards. As this runoff moves across the land surface, it picks up soil particles and pollutants, such as nutrients and pesticides.

overdraft—that quantity of water pumped in excess of the available supply; the act of overdrawing a water supply or aquifer in amounts greater than replenishment. Also, the sustained extraction of groundwater from an aquifer at a rate greater than the recharge rate of the aquifer, resulting in a drop in the level of the water table.

ozonation—a water treatment process that destroys bacteria and other micro-organisms. It's one of the most advanced water treatment processes in the industry.

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particles—small bits of matter.

pathogen—disease-causing agents; usually bacteria or viruses.

percolate—to drain or seep through a porous and permeable substance; to filter, such as liquid passing through a porous body (water through soil to an aquifer).

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 impermeable material, such as clay, doesn't allow water to flow freely.

perspire—to sweat; to lose water through skin.

pH—a measure of the concentration of hydrogen ions in solution. The pH scale ranges from 0-14, where 7.0 is neutral; values less than 7.0 are acidic; and values greater that 7.0 are alkaline or basic. Every unit decrease in pH means a 10 fold increase in concentration. Thus, a pH of 3.0 is 10 times as acidic as a pH of 4.0 and 100 times more acidic than a pH of 5.0.

phosphates—important ion and plant nutrient; found in many fertilizers.

point source pollution—pollution that can be traced to a single source such as a pipe or an outlet (example: wastewater treatment plant, industrial sites, etc.).

polar molecule—a covalent molecule having a partial positive (+) and a partial negative (-) end.

pollutant—any substance suspended or dissolved in water that builds up in sufficient quantity to impair water quality.

polluted water—water that contains one or more impurities that make the water unsuitable for a desired use.

pond—a still body of water smaller than a lake.

porosity—a description of the total volume of rock or soil not occupied by soil matter.

potable water—water suitable for drinking.

precipitation—any form of water, such as rain, snow, sleet, or hail, that falls to the earth's surface

primary treatment—the first stage of wastewater treatment that removes settled or floating solids only; generally removes about 40 percent of the suspended solids.

pumping station—a facility that pumps water to a higher elevation.

purveyor or provider—with reference to public water supply systems, a municipality or other organization that sells and delivers water to customers. There are seven purveyor members in the Southern Nevada Water Authority: the cities of Boulder City, Henderson, Las Vegas and North Las Vegas; Big Bend Water District; Clark County Sanitation District and the Las Vegas Valley Water District.

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receiving reservoir—a water holding structure at the terminal end of a delivery system constructed and equipped to provide storage and release of water.

recharge—to replenish a water body or an aquifer with water; the replacement of any water that may have flowed out or been pumped out of an aquifer.

recharge area—an area where infiltration moves downward into an aquifer.

reclamation—bringing land that has been disturbed by some process back to its original condition.

regulating tank—a tank constructed for the purpose of regulating system hydraulics within an acceptable range over a particular reach of the transmission facilities. A regulating tank absorbs pressure fluctuations and temporary mismatches between downstream demands and upstream water supplies to maintain a balanced operation.

rehydrate—to replace lost water.

reservoir—a place where water is collected and stored for use.

return flow credit—credits Nevada receives for treating wastewater and returning it to the Colorado River System.

riparian—areas adjacent to rivers and streams with plants adapted to moist growing conditions found along waterways and shorelines. These areas are frequently important to wildlife habitat because of their greater density and succulence.

river—a large body of flowing water that receives water from other streams and/or rivers.

River Mountains Tunnels—two 3.9 mile tunnels that convey water from Lake Mead through the River Mountains to the Las Vegas Valley. One tunnel is 10 feet in diameter, constructed in 1971. The other tunnel is 12 feet in diameter and was constructed in 1997.

ROFC Station—Rate-of-Flow Control Station. A facility constructed to control the rate at which water is delivered to a turnout.

runoff—water that flows across surfaces rather than soaking into the ground; eventually enters a body of water; may carry a variety of pollutants.

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Saddle Island—a small island on Lake Mead where two water intakes draw water from the lake for delivery to the water treatment facilities.

salt water—water that has a high level of dissolved salts (oceans, seas).

saturated zone—a portion of the soil where all pores are filled with water. Aquifers are located in this zone. There may be multiple saturation zones at different soil depths separated by layers if clay or rock.

secondary treatment—a type of wastewater treatment process used to convert dissolved and suspended pollutants into a form that can be removed; a minimum level of treatment for municipal wastewater as required by the Clean Water Act.

sedimentation—a process that occurs when gravity pulls the clumps of sediment to the bottom.

sludge—any solid, semisolid or liquid waste that settles to the bottom of sedimentation tanks or septic tanks.

soft water—water that is relatively free of those minerals that cause soap to precipitate causing scale buildup.

solvent—a substance that dissolves another to form a solution.

Southern Nevada Water Authority (SNWA)—A seven member agency established in 1991 to address regional water issues in Southern Nevada. The member agencies are the cities of Boulder City, Henderson, Las Vegas and North Las Vegas; Big Bend Water District; Clark County Sanitation District and Las Vegas Valley Water District.

Southern Nevada Water System (SNWS)—A system of water treatment and transmission facilities, including intakes, pumping stations, treatment facilities, rate-of-flow control stations, pipelines and aqueducts. The SNWS treats water from Lake Mead and sends it to the various water purveyors for distribution.

specific heat—the number of calories needed to raise the temperature of one gram of a given substance 1degree C, compared to the number of calories (one) needed to raise the temperature of one gram of water 1 degree C.

spillway—the channel or passageway around or over a dam used to divert excess water.

spring—a concentrated discharge of groundwater flowing out at the surface.

State Engineer—the head of the State of Nevada Division for Water Resources. The state engineer is responsible for granting rights to surface water and groundwater in the state of Nevada.

storage tanks—water tanks that are used for storage and which come in several shapes and sizes: elevated, ground and standpipe.

stream—a body of flowing fresh water.

surface tension—a property of liquids in which the exposed surface tends to contract to the smallest possible area. It is caused by unequal molecular cohesive forces near the surface.

survive—to remain alive or in existence.

system—an orderly, interconnected arrangement of parts.

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tap water—water from a faucet (generally treated by a municipal water system and piped to homes and businesses).

temperature—the degree of heat or cold.

thermometer—an instrument used to measure temperature.

Total Dissolved Solids (TDS)—the inorganic or mineral content of water. Lake Mead TDS varies from 550 to 750 milligrams per liter, depending on changing lake levels.

toxic—harmful to living organisms.

transmission facility—transmits water from the treatment facility. The transmission system includes forebays, pumping equipment, regulating tanks, tunnels, piping, metering equipment and flow control equipment. For convenience in more specific reference, distinct branches of the transmission system may be identified and assigned unique names (see lateral).

transpiration—process in which water that is absorbed by the roots of plants moves up through the plant, passes through pores in the leaves and then evaporates into the atmosphere as water vapor.

treatment facility—the system that receives water from the intake system, processes the water to meet established water-quality standards and delivers it to the transmission facility.

tributary—a stream or other body of water, surface or underground, which contributes its water, even though intermittently and in small quantities, to another and larger stream or body.

trough—a long open receptacle.

turbidity—the cloudy or muddy appearance of natural water caused by the suspension of particulate matter.

turbine—an engine run by the reaction, impulse or both of a current (such as a water current).

turnout—the point of delivery of water from the Southern Nevada Water System transmission facility to a municipal water purveyor.

unaccounted water—water use that has not been metered or recorded. Unaccounted water is not necessarily lost or stolen water.

unconfined aquifer—an aquifer containing groundwater that is not pressurized, having an impermeable layer below but not above it.

underground storage tank—any tank, including underground pipes connected to a tank, that has at least 10 percent of its volume underground and usually contains petroleum products or hazardous substances.

universal solvent—water; a material that can dissolve almost any other substance.

unpotable water—not suitable to drink.

vapor—a substance in a gaseous state.

variable—factor that may cause the results of an experiment or investigation to change (a controlled variable must remain constant throughout an experiment).

viscosity—the state or quality of having a cohesive and sticky fluid consistency; a measure of resistance to flow.

waterborne diseases—diseases spread by contaminated water.

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water cooler—a free-standing container of water available for drinking.

water consumption—the quantity of water permanently removed over a given time period from a water source. (With respect to Nevada's use of the Colorado River, a quantity of water equal to water diversions after return flow credits are accumulated.) Nevada is presently allocated a consumption limit of 300,000 acre-feet per year from the Colorado River.

water cycle—continuous movement of water from the oceans and fresh water sources to the air and land and then back to the oceans.

water diversions—with respect to Nevada's use of the Colorado River, the quantity of water removed from the river over a certain time period. Water diversions from the Colorado River allowed by the U.S. Government are defined in various contract documents.

water loss—water that leaks, evaporates or otherwise escapes from the water supply system before it can be put to use.

water quality—a term used to describe the chemical, physical and biological characteristics of Water with respect to its suitability for a particular use.

water resource—the quantity of Water available in a certain time period from which a Water supply may be developed. The Colorado River is the primary Water resource for Southern Nevada's Water supply. Other Water resources available to Southern Nevada include groundwater, the Muddy River and the Virgin River.

watershed—land area from which water drains to a particular surface water body.

water source—the place or thing from which water begins or arises.

water supply—Water available in a system for its intended use. Water diverted from the Colorado River and treated to drinking Water standards becomes part of the Southern Nevada Water System's Water supply.

water table—the upper surface of a zone of saturation; the upper surface of the groundwater.

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.

weather—conditions of heat, cold, wetness, dryness, clearness, cloudiness, etc.

well—a bored, drilled or driven shaft or dug hole. Wells range from a few feet to more than 6 miles in depth, but most water wells are between 100 and 2,000 feet in depth.

wellhead—the physical structure or device at the land surface from or through which groundwater flows or is pumped.

wetlands—areas that periodically have waterlogged soils or are covered with a shallow layer of water. Wetland areas typically support plant life that are adapted to life in wet environments.

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xeriscape (pronounced "zeer-ih-scape")—a Water-efficient landscape design that incorporates low-Water use plants.

zone of saturation—that region below the surface in which all voids are filled with liquid.