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Water glossary



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Water Glossary - C

  • Cake: Solid dewatered residue on a filter media after filtration.

  • Calcium carbonate: CaCO3 - a white precipitate that forms in water lines, water heaters and boilers in hard water areas; also known as scale

  • Calcium hypochlorite: A chemical that is widely used for water disinfection, for instance in swimming pools or water purification plants. It is especially useful because it is a stable dry powder and can be made into tablets.

  • Calorie: Amount of energy required to raise the temperature of 1 gram of water 1 degree Celsius

  • Candle filter: A relatively coarse aperture filter, designed to retain a coat of filter medium on an extended surface.

  • Capillary action: Water that at some point rises higher than that portion of its surface, not in contact with the solid surface. This is due to adhesion, cohesion and surface tension where later touches a solid.

  • Capillary zone: Soil area above the water table where water can rise up slightly through the cohesive force of capillary action. See phreatophytes

  • Cappilary membranes: Membranes about the thickness of a human hair, used for Reverse Osmosis, nanofiltration, ultrafiltration and microfiltration.

  • Carbamates: A class of new-age pesticides that attack the nervous system of organisms

  • Carbonate hardness: Hardness of water caused by carbonate and bicarbonate by-products of calcium and magnesium.

  • Carbonates: The collective term for the natural inorganic chemical compounds related to carbon dioxide that exist in natural waterways

  • Carcinogen: Any dissolved pollutant that can induce cancer.

  • Cartridge filter: Disposable filter device that has a filter range of 0.1 micron to 100 microns.

  • Casing: A tubular structure intended to be watertight installed in the excavated or drilled hole to maintain the well opening and, along with cementing, to confine the ground waters to their zones of origin and prevent the entrance of surface pollutants

  • Catalyses: Chemical that increases the rate of a reaction but does not take a direct part in the reaction, so that it is still intact after the reaction has taken place.

  • Catch basin: A sedimentation area designed to remove pollutants from runoff before being discharged into a stream or pond.

  • Cation: A negatively charged ion, resulting from dissociation of molecules in solution.

  • Cavern: A large underground opening in rock (usually limestone) which occurred when some of the rock was dissolved by water. In some igneous rocks, caverns can be formed by large gas bubbles

  • Cement grout: A mixture of water and cement in the ratio of not more than 5-6 gallons of water to a 94 pound sack of Portland cement which is fluid enough to be pumped through a small diameter pipe

  • Center pivot system: Method of agricultural irrigation consisting of a single sprinkler lateral with one end anchored to a fixed pivot structure and the other end continuously moving around the pivot while applying water

  • Centrifugation: A separation process, which uses the action of centrifugal force to promote accelerated settling of particles in a solid-liquid mixture.

  • CERCLA: Comprehensive Environment Response, Compensation and Liability Act. Also known as SUPERFUND. The Act gave EPA the authority to clean up abandoned, leaky hazardous waste sites

  • Certificate of water right: An official document which serves as court evidence of a perfected water right

  • CFU: Colony Forming Units. This is a measure that indicates the number of microorganisms in water.

  • Check dam: A small dam constructed in a gully or other small water course to decrease the streamflow velocity, minimize channel erosion, promote deposition of sediment and to divert water from a channel

  • Check valve: A valve that allows water to stream in one direction and will then close to prevent development of a back-flow.

  • Chelating agents: Organic compounds that have the ability to draw ion from their water solutions into soluble complexes.

  • Chemical Oxygen Demand (COD): The amount of oxygen (measured in mg/L) that is consumed in the oxidation of organic and inorganic matter, under test conditions. It is used to measure the total amount of organic and inorganic pollution in wastewater. Contrary to BOD, with COD practically all compounds are fully oxidized.

  • Chemical pollution: Introduction of chemical contaminants into a water body.

  • Chemical weathering: Attack and dissolving of parent rock by exposure to rainwater, surface water, oxygen, and other gases in the atmosphere, and compounds secreted by organisms. Contrast physical weathering

  • Chiseling of compacted soils: Loosening the soil, without inverting and with a minimum of mixing of the surface soil, to shatter restrictive layers below the normal plow depth that inhibit water and air movement or root development

  • Chloramines: A chemical complex that consists of chlorine and ammonia. It serves as a water disinfectant in public water supplies in place of chlorine because chlorine can combine with organics to form dangerous reaction products. In which forms chloramines exist depends on the physical/ chemical properties of the water source.

  • Chlorinated hydrocarbons: Hydrocarbons that contain chlorine. These include a class of persistent insecticides that accumulate in the aquatic food chain. Among them are DDT, aldrin, dieldrin, heptachlor, chlordane, lindane, endrin, Mirex, hexachloride, and toxaphene.

  • Chlorinated solvent: An organic solvent containing chlorine atoms that is often used as aerosol spray container, in highway paint, and dry cleaning fluids.

  • Chlorination: A water purification process in which chlorine is added to water for disinfection, for the control of present microorganisms. It is also used in the oxidation of compound impurities in water.

  • Chlorine demand: The difference between the amount of chlorine added to water, sewage, or industrial wastes and the amount of residual chlorine remaining at the end of a specific contact period. Compare residual chlorine

  • Chlorine-contact chamber: The part of a water treatment plant where effluent is disinfected by chlorine.

  • Chute spillway: The overall structure which allows water to drop rapidly through an open channel without causing erosion. Usually constructed near the edge of dams

  • Circulate: To move in a circle, circuit or orbit; to flow without obstruction; to follow a course that returns to the starting point

  • Cistern: A tank used to collect rainwater runoff from the roof of a house or building

  • Clarity: The clearness of a liquid.

  • Climate: Meteorological elements that characterize the average and extreme conditions of the atmosphere over a long period of time at any one place or region of the earth's surface.

  • Climate change: The slow variations of climatic characteristics over time at a given place.

  • Climatic cycle: The periodic changes climate displays, such as a series of dry years following a series of years with heavy rainfall

  • Climatic year: A period used in meteorological measurements. The climatic year in the U.S. begins on October 1

  • Closed loop cooling tower: Water-conserving cooling tower system in which water used for cooling is recycled through a piping system that cools the water; the water is cooled as air exchanges heat with the pipes

  • Cloudburst: A torrential downpour of rain, which by it spottiness and relatively high intensity suggests the bursting and discharge of water from a cloud all at once

  • Coagulation: In water treatment, the use of chemicals to make suspended solids gather or group together into small flocs

  • Coalescence: Liquid particles in suspension that unite to create particles of a greater volume.

  • Coastal zone: Lands and waters near the coast, whose uses and ecology are affected by the sea.

  • Cohesion: A molecular attraction by which the particles of a body are united throughout the mass whether like or unlike. Compare adhesion

  • Cold vapor: Method to test water for the presence of mercury

  • Coliform bacteria: A group of bacteria used as an indicator of sanitary quality in water. Exposure to these organisms in drinking water causes diseases such as cholera.

  • Coliform index: A rating of the purity of water based on a count of coliform bacteria.

  • Collector sewers: Pipes to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility.

  • Collector well: A well located near a surface water supply used to lower the water table and thereby induce infiltration of surface water through the bed of the water body to the well.

  • Colloids: Finely divided solids which will not settle but which may be removed by coagulation or biochemical action

  • Combined sewer: A sewer system that carries both sanitary sewage and stormwater runoff. When sewers are constructed this way, wastewater treatment plants have to be sized to deal with stormwater flows and oftentimes some of the water receives little or no treatment. Compare separate sewer

  • Commercial water use: Water for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions. The water may be obtained from a public supply or may be self supplied. See also public supply and self- supplied water.

  • Community water system: A public water system which serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.

  • Completion: Sealing off access of undesirable water to the well bore by proper casing and/or cementing procedures

  • Composite sample: A series of water samples taken over a given period of time and weighted by flow rate.

  • Composite sample, weighted: A sample composed of two or more portions collected at specific times and added together in volumes related to the flow at time of collection. Compare grab sample

  • Compounds: Two or more different elements held together in fixed proportions by attractive forces called chemical bonds.

  • Concentrate: The totality of different substances that are left behind in a filter medium after filtration.

  • Concentration: Amount of a chemical or pollutant in a particular volume or weight of air, water, soil, or other medium

  • Concentration process: The process of increasing the number of particles per unit volume of a solution, usually by evaporating the liquid.

  • Condensate: Water obtained by condensation of water vapor.

  • Condensation: The process by which a vapor becomes a liquid or solid; the opposite of evaporation. In meteorological usage, this term is applied only to the transformation from vapour to liquid.

  • Condensation: The change of state from a gas to a liquid. Compare evaporation, sublimation

  • Conductivity: The amount of electricity the water can conduct. It is expressed in a chemical magnitude. Please use also our information about TDS and conductivity.

  • Conduit: A natural or artificial channel through which fluids may be conveyed

  • Cone of depression: Natural depression in the water table around a well during pumping

  • Confined aquifer: An aquifer that lies between two relatively impermeable rock layers

  • Confining bed or unit: A body of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers

  • Confluent growth: In coliform testing, abundant or overflowing bacterial growth which makes accurate measurement difficult or impossible

  • Conjunctive management: Integrated management and use of two or more water resources, such as an aquifer and a surface water body

  • Connate growth: Water trapped in the pore spaces of a sedimentary rock at the time it was deposited. It is usually highly mineralized

  • Conservation: The continuing protection and management of natural resources in accordance with principles that assure their optimum long-term economic and social benefits.

  • Consolidated formation: Naturally occurring geologic formations that have been lithified (turned to stone). The term is sometimes used interchangeably with the term "bedrock." commonly, these formations will stand at the edges of a bore hole without caving

  • Consumptive use: The difference between the total quantity of water withdrawn from a source for any use and the quantity of water returned to the source; e.g., the release of water into the atmosphere; the consumption of water by humans, animals, and plants; and the incorporation of water into the products of industrial or food processing.

  • Contact recreation: Activities involving a significant risk of ingestion of water, such as wading by children, swimming, water skiing, diving and surfing. Compare noncontact recreation.

  • Contact time: The length of time a substance is in contact with a liquid, before it is removed by filtration or the occurrence of a chemical change.

  • Contaminant: Any physical, chemical, biological, or radiological substance or matter that has an adverse affect on air, water, or soil.

  • Contamination: The introduction into water of sewage or other foreign matter that will render the water unfit for its intended use

  • Continuous flow system: The continuous use, by an industry, of deionized water to remove contaminants from products and equipment

  • Conventional sewer systems: Systems that were traditionally used to collect municipal wastewater in gravity sewers and convey it to a central primary or secondary treatment plant, before discharge on receiving surface waters.

  • Conveyance loss: Water that is lost in transit from a pipe, canal, conduit, 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.

  • Cooling pond: Usually a manmade water body used by power plants or large industrial plants that enables the facility to recirculate once-through cooling water. The water levels in the pond are usually maintained by rainfall or augmented by pumping (withdrawal of) water from another source (fresh, saline, or reclaimed).

  • Cooling tower: A large tower or stack that is used for heat exchange of once-through cooling water generated by steam condensers. Hot water from the plant is sprayed into the top of the tower and exchanges heat with the passing air as it falls. The water is then collected at the bottom of the tower and used again. A small amount of water is lost (consumed) through evaporation in this process. See cooling water or once-through cooling.

  • Cooling tower makeup: Water added to the recirculating cooling tower water stream to compensate for water evaporation losses

  • Cooling water: Water used for cooling purposes, such as of condensers and nuclear reactors.

  • Cooling water blowdown: Procedure used to reduce total dissolved solids by removing a portion of poor-quality recirculating water

  • Cooling water drift: Unevaporated water carried out of a cooling tower by the airflow; it has the same composition as the recirculating water

  • Cooling water evaporation: Cooling water recycling approach in which water loses heat when a portion of it is evaporated

  • Correlative rights: Rights that are coequal or that relate to one another, so that any one owner cannot take more than his share

  • Creek: A small stream of water which serves as the natural drainage course for a drainage basin. The term is relative according to size. Some creeks in a humid region would be called rivers if they occurred in an arid area

  • Crest: The top of a dam, dike, or spillway, which water must reach before passing over the structure; the summit or highest point of a wave; the highest elevation reached by flood waters flowing in a channel

  • Critical low flow: Low flow conditions below which some standards do not apply. The impacts of permitted discharges are analyzed at critical low-flow

  • Cross flow filtration: A process that uses opposite flows across a membrane surface to minimize particle build-up.

  • Cryptosporidium: A microorganism in water that causes gastrointestinal illness in humans. It is commonly found in untreated surface water and can be removed by filtration. It is resistant to disinfectants such as chlorine.

  • Cubic foot per second (CFS): The rate of discharge representing a volume of one cubic foot passing a given point during 1 second. This rate is equivalent to approximately 7.48 gallons per second, or 1.98 acre-feet per day

  • Cubic metre per second (m3/s): A unit expressing rate of discharge, typically used in measuring streamflow. One cubic meter per second is equal to the discharge in a stream of a cross section one meter wide and one meter deep, flowing with an average velocity of one meter per second.

  • Cultural eutrophication: Decline of the oxygen rate in water, which has serious consequences for aquatic life, caused by humans.

  • Current: The portion of a stream or body of water which is moving with a velocity much greater than the average of the rest of the water. The progress of the water is principally concentrated in the current. See thalweg

  • Cycle: The length of time a filter can be used before it needs cleaning, usually including cleaning time.

Water glossary