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C-CELSIUS—Centigrade Temperature Scale C-HORIZON—a layer of unconsolidated material, relatively little affected by the influence of organisms and presumed to be similar in chemical, physical, and mineralogical composition to the material from which at least a portion of the overlying Solum has developed. CAA—Clean Air Act (EPA) CABOTAGE—Trade or transport in coastal waters or airspace or between two points within a country. CAISSON—(1) A watertight structure within which construction work is carried on under water. (2) A large box open at the top and one side, designed to fit against the side of a ship and used to repair damaged hulls under water. (3) A floating structure used to close off the entrance to a dock or canal lock. Also referred to as a Camel. CALCAREOUS—Formed of calcium carbonate or magnesium carbonate by biological deposition or inorganic precipitation in sufficient quantities to effervesce carbon dioxide visibly when treated with cold 0.1 normal hydrochloric acid. Calcareous sands are usually formed of a mixture of fragments of mollusk shell, echinoderm spines and skeletal material, coral, foraminifera, and algal platelets. CALCAREOUS FENS—Peatlands formed in areas of groundwater discharge, where cold, anoxic, mineral-rich water provides a specialized habitat for disproportionately large numbers of rare and endangered plants. Many of the plants found in calcareous fens are species which would be typical of more northern habitats. The health of such fens is inextricably linked to the presence of the upwelling groundwater. Also see Peat (Peatlands).
CALCINE—Heated to temperature of dissociation; for example, heat gypsum to the temperature where the water of crystallization is driven off. CALCITE—(Geology) Calcium carbonate (CaCO3), with hexagonal crystallization, a mineral found in the form of limestone, chalk, and marble. CALCIUM—(Ca++) The most abundant cation found in Wisconsin lakes. Its abundance is related to the presence of calcium-bearing minerals in the lake watershed. Reported as milligrams per liter (mg/l) as calcium carbonate (CaCO3), or milligrams per liter as calcium ion(Ca++). CALCIUM CARBONATE—(CaCO3) The principal hardness and scale-causing compound in water. A white precipitate that forms in water lines, water heaters, and boilers in hard water areas; also known as scale. Also the principal chemical composition of Tufa, a calcareous and siliceous rock deposit of springs, lakes, or ground water. CALCIUM CARBONATE TREATMENT—The adding of limestone (calcium carbonate) to an acid lake to raise the pH. CALCIUM CHLORIDE—A white deliquescent compound, CaCl2, used chiefly as a drying agent, refrigerant, and preservative and for controlling dust and ice on roads. CALCIUM HYDROXIDE—A white crystalline strong alkali Ca(OH)2 that is used especially to make mortar and plaster and to soften water. CALCIUM NITRATE TREATMENT—A method of adding nitrate to lake sediments. CALF—A large floating chunk of ice split off from a glacier, an iceberg, or a floe. CALGON—Trademark product used for a water softener. CALICHE—(1) A soil layer near the surface, more or less cemented by secondary carbonates of calcium or magnesium precipitated from the soil solution. It may occur as a soft, thin soil horizon, as a hard, thick bed just beneath the Solum, or as a surface layer exposed by erosion. (2) Alluvium cemented with sodium nitrate, chloride, and/or other soluble salts in the nitrate deposits of Chile and Peru. Also referred to as Hardpan. CALIFORNIA DOCTRINE—A system of allocating water, first announced in California, which combines Riparian Rights and Appropriative Rights. A number of states have applied this doctrine at one time or another. However, most states have essentially abandoned the doctrine in favor of the Appropriation Doctrine, and it is primarily of historical significance. Also see Alpine Decree [California and Nevada].
CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA)—The California equivalent of the federal National Environmental Policy Act (NEPA). CALIFORNIA STATE WATER RESOURCES CONTROL BOARD (SWRCB)—See State Water Resources Control Board (SWRCB) [California]. CALIFORNIA WATER COMMISSION—See Department of Water Resources (DWR) [California]. CALM—A period or condition of freedom from storms, high winds, or rough activity of water. CALORIE—(Abbreviation cal) (1) Basically, A unit of heat energy equal to the amount of heat needed to raise the temperature of one gram of water one degree Celsius (C). More precisely, any of several approximately equal units of heat, each measured as the quantity of heat required to raise the temperature of 1 gram of water by 1C from a standard initial temperature, especially from 3.98C (corresponding to the maximum density of water), 14.5C, or 19.5C, at 1 atmosphere pressure. Also referred to as the Gram Calorie and the Small Calorie. (2) The unit of heat equal to 1/100 the quantity of heat required to raise the temperature of 1 gram of water from 0C (its freezing point) to 100C (its boiling point) at 1 atmosphere pressure. Also referred to as the Mean Calorie. (3) The unit of heat equal to the amount of heat required to raise the temperature of 1 kilogram of water by 1C at 1 atmosphere pressure. Also referred to as the Kilocalorie, Kilogram Calorie, and Large Calorie. (4) A unit of energy-producing potential equal to this amount of heat that is contained in food and released upon oxidation by the body. Also referred to as the Nutritionist's Calorie. The calorie is used when temperature is measured in degrees Celsius (C) on the Centigrade Scale. The British Thermal Unit (BTU) is used when the measurement is in degrees Fahrenheit (F) on the Fahrenheit Scale. CALVE—To break at an edge, sot that a portion separates. Used of a glacier or an iceberg. CAMEL—A device used to raise sunken objects, consisting of a hollow structure that is submerged, attached tightly to the object, and pumped free of water. Also referred to as a Caisson. CAMP SCAR—Camp sites on wilderness and primitive lakes are easily recognized from the water surface and air by their lighter tone and barren character. Landing beaches are cleared, ground cover is destroyed and large trees are dead or dying from soil compaction. Damage to the aesthetic image is frequently accentuated by blazes, temporary structures and bark stripping. CANAL—A constructed open channel for transporting water. CANAL, BOAT—A dredged canal between separate lakes or lakes and streams to provide convenient boat passage. CANAL AUTOMATION—The implementation of a control system that upgrades the conventional method of canal system operation. CANAL CHECK GATE STRUCTURE—A structure designed to control the water surface level and flow in a canal, maintaining a specified water depth or head on outlets or turnout structures. Most canal check structures have movable gates. CANAL FREEBOARD—The amount of canal lining available above maximum design water depth. CANAL POOL—Canal section between check structures CANAL PRISM—The cross-sectional shape of a typical canal. CANAL REACH—The segment of the main canal system consisting of a series of canal pools between major flow control structures. CANAL SYSTEM OPERATION—Water transfer from its source to points of diversion for irrigation, municipal and industrial, fish and wildlife, and drainage purposes. CANCELED WATER RIGHT—A water right that is invalidated due to the failure of the water right holder to comply with the terms and conditions of the permit. Also see Forfeited Water Right and Withdrawn Water Right.
CANDIDATE SPECIES—Plant or animal species designated by the Department of the Interior, U.S. Fish and Wildlife Service (USFWS) as candidates for potential future listing as an Endangered Species or Threatened Species pursuant to the Endangered Species Act (ESA) of 1973; plant or animal species that are candidates for designation as endangered (in danger of becoming extinct) or threatened (likely to become endangered). CANOE— A light narrow boat made of bark, aluminum, or fiberglass. A paddle is used to steer and move it. CANOE TRAIL—Connected lakes or closely associated lakes and streams used as canoe routes. Portages used in overland travel between water bodies and camp sites may be either marked or developed; (1) wilderness area canoe routes are long and provide no facilities, (2) primitive area canoe routes are of variable length and have developed portages and camp sites, (3) canoe routes in populated agricultural and forest areas may be quite short and have hotels, organized campgrounds and pick-up service. CANOPY—The overhanging cover formed by leaves, needles, and branches of vegetation. CANOPY CLOSURE—The degree of canopy cover relative to openings (Forestry Canada 1992). Class 1 has a cover of a few individuals, and class 9 has continuous canopy cover with no gaps. CANYON, also Cañon—A narrow chasm with steep cliff walls, cut into the earth by running water; a gorge. CAP—A layer of clay, or other impermeable material installed over the top of a closed landfill to prevent entry of rainwater and minimize Leachate. CAPA (CRITICAL AQUIFER PROTECTION AREA)—As defined in the Safe Drinking Water Act (SDWA), is all or part of an area located within an area for which an application of designation as a sole or principal source aquifer (pursuant to Section 1424[e]) has been submitted and approved by the Administrator not later than 24 months after the date of enactment and which satisfies the criteria established by the Administrator; and all or part of an area that is within an aquifer designated as a Sole Source Aquifer (SSA), as of the date of the enactment of the Safe Drinking Water Act (SDWA) amendments of 1986, and for which an area wide ground-water protection plan has been approved under Section 208 of the Clean Water Act (CWA) prior to such enactment. CAPACITIVE DEIONIZATION (CDI)—A relatively simple and straight forward electrochemical reaction process made unique and highly efficient through the development of a highly-porous material called carbon aerogel that absorbs huge volumes of ions. A single cube of carbon aerogel, one inch on a side, has an effective surface area of more than 20 million square inches. This unusually high surface area makes it possible to adsorb large numbers of ions. Water containing salt, heavy metals, or even radioactive isotopes is pumped through a series of electrochemical cells made from the aerogel, a material sometimes called "frozen smoke." Effluent water from the series of stacked cells is subsequently purified. The trapped ions can be released into a relatively small stream of "rinse" water typically comprising less than one percent of the total volume of produce water. Also see Deionization.
CAPACITY, FIELD or SOIL—The amount of water held in a soil sample after the excess gravitation water has drained away. CAPACITY, GROSS RESERVOIR—The total amount of storage capacity available in a reservoir for all purposes from the streambed to the normal maximum operating level. It does not include surcharge, but does include dead storage. CAPE—(1) A point or head of land projecting into a body of water. (2) A rounded projection, out into the water, and either high land or low land. For inland lakes, cape rarely appears on maps as a place name and also only infrequently in descriptions. Point and head according to present usage appears to be preferred to cape. CAPILLARITY—(1) The property of tubes or earth-like particles with hair-like openings which, when immersed in fluid, raise (or depress) the fluid in the tubes above (or below) the surface of the fluid in which they are immersed. (2) The interaction between contacting surfaces of a liquid and a solid that distorts the liquid surface from a planar shape. Also referred to as Capillary Action or Capillary Attraction. CAPILLARY ACTION—(1) The action by which water is drawn around soil particles because there is a stronger attraction between the soil particles and the water molecules themselves. (2) The movement of water within the interstices of a porous medium due to the forces of adhesion, cohesion, and surface tension acting in a liquid that is in contact with a solid. Synonymous with the terms Capillarity, Capillary Flow, and Capillary Migration. CAPILLARY ATTRACTION—The force that results from greater adhesion of a liquid to a solid surface than internal cohesion of the liquid itself and that causes the liquid to be raised against a vertical surface, as water is in a clean glass tube. It is the force that allows a porous material like soil to soak up water from lower levels. CAPILLARY FRINGE—(1) The zone at the bottom of the Zone of Aeration (Vadose Zone) where ground water is drawn upward by capillary force. (2) The zone immediately above the Zone of Saturation (or Groundwater Table) in which underground water is lifted against gravity by surface tension (Capillary Action) in passages of capillary size.
CAPILLARY PHENOMENA—A phenomenon of water movement caused by Capillarity. CAPILLARY POTENTIAL—The work required to move a unit mass of water from the reference plane to any point in the soil column. CAPILLARY RISE—The height above a free water surface to which water will rise by Capillary Action. CAPILLARY WATER—(1) Water held in the soil above the Phreatic Surface by capillary forces; or soil water above hydroscopic moisture and below the field capacity. (2) A continuous film of water found around soil particles. CAPILLARY ZONE—The soil area above the water table where water can rise up slightly through the cohesive force of Capillary Action. CAPTURE—(1) Water withdrawn artificially from an aquifer is derived from a decrease in storage in the aquifer, a reduction in the previous discharge from the aquifer, an increase in the recharge, or a combination of these changes. The decrease in discharge from an aquifer plus the increase in recharge. Capture may occur in the form of decreases in the ground-water discharge into streams, lakes, and the ocean, or from decreases in that component of Evapotranspiration derived from the Zone of Saturation. (2) Diversion of the flow of water in the upper part of a stream by the headward growth of another stream. CAPTURE ZONE—The zone around a well contributing water to the well; the area on the ground surface from which a well captures water. CARBAMATES—A class of new-age pesticides that attack the nervous system of organisms. CARBON—A nonmetallic element found in all organic substances and in some inorganic substances, as diamonds, coal, graphite, charcoal and lampblack. CARBON ADSORPTION—(Water Quality) A treatment system that removes contaminants from ground water or surface water by forcing it through tanks containing activated carbon treated to attract the contaminants.
CARBON-CHLOROFORM EXTRACT (CCE)—A measurement of the organic content of a water. It consists of adsorbing the organic matter onto activated carbon, then extracting it with chloroform. CARBON FILTRATION—(Water Quality) The passage of treated wastewater or domestic water supplies through activated charcoal in an effort to remove low concentrations of dissolved chemicals. CARBON DIOXIDE—A colorless, odorless, nonpoisonous gas, CO2, that forms Carbonic Acid when dissolved in water. Carbon dioxide is typically produced during combustion and microbial decomposition. Because carbon dioxide absorbs infrared radiation, rising levels of carbon dioxide in the global atmosphere over the past century have prompted concerns about climatic change and more specifically the Greenhouse Effect. CARBON POLISHING—(Water Quality) The removal of residual dissolved organic substances from wastewater by Adsorption on activated charcoal (granular activated carbon). A form of Tertiary Wastewater Treatment. CARBON TREATMENT—(Water Quality) In a drinking water purification process, the removal of Colloids by Adsorption on Activated Charcoal. This step often improves the color, taste, and odor of drinking water. Also see Secondary Drinking Water Standards. CARBONACEOUS BIOCHEMICAL OXYGEN DEMAND—The incubation of a sample of water or wastewater for a relatively short period of time in order to determine the Biochemical Oxygen Demand (BOD). The short incubation, usually 5 days, is sufficient to detect only the microbial utilization of carbon compounds. A longer incubation (15 to 20 days) would also detect the oxidation of inorganic nitrogenous compounds (ammonia and nitrite) and the subsequent demand for molecular oxygen by chemoautotrophic bacteria.
CARBONATE—(1) The collective term for the natural inorganic chemical compounds related to carbon dioxide that exist in natural waterways. (2) A sediment formed by the organic or inorganic precipitation from aqueous solution of carbonates of calcium, magnesium, or iron. The CO3-2 ion in the Carbonate Buffer System. Combined with one proton, it becomes Bicarbonate, HCO3- and with two protons, Carbonic Acid. The carbonate ion forms a solid precipitant when combined with dissolved ions of calcium or magnesium. CARBONATE AQUIFER—An aquifer found in limestone and dolomite rocks. Carbonate aquifers typically produced hard water, that is, water containing relatively high levels of calcium and magnesium. CARBONATE BUFFER SYSTEM—The most important buffer system in natural surface waters and wastewater treatment, consisting of a carbon dioxide, water, carbonic acid, Bicarbonate, and Carbonate ion equilibrium that resists changes in the water's pH. For example, if acid materials (hydrogen ions) are added to this buffer solution, the equilibrium is shifted and carbonate ions combine with the hydrogen ions to form bicarbonate. Subsequently, the bicarbonate then combines with hydrogen ions to form carbonic acid, which can dissociate into carbon dioxide and water. Thus the system pH is unaltered even though acid was introduced. CARBONATE HARDNESS—Water hardness caused by the presence of Carbonate and Bicarbonate of calcium and magnesium. Also see Temporary Hardness. CARBONATE ROCK—(Geology) A rock consisting chiefly of carbonate minerals, such as limestone and dolomite. CARBONATED WATER—(1) Effervescent water, usually containing salts, charged under pressure with purified carbon dioxide gas, used as a beverage or mixer. Also referred to as soda water, club soda, or seltzer. (2) A solution of water, sodium bicarbonate, and acid. CARBONATION, GROUNDWATER—The dissolving of carbon dioxide in surface water as it percolates through the ground. The carbon dioxide reacts with water to form carbonic acid, a weak acid that causes the water to have a slightly acidic pH. CARBONIC ACID—A weak, unstable acid, H2CO3, present in solutions of carbon dioxide and water. The carbonic acid content of natural, unpolluted rainfall lowers its pH to about 5.6. CARCINOGEN—A cancer-causing substance or agent.
CARCINOGENIC—Cancer causing. CARLSON'S TROPHIC STATE INDEX (TSI)—A measure of Eutrophication of a body of water using a combination of measures of water transparency or turbidity (using Secchi Disk depth recordings), Chlorophyll-a concentrations, and total phosphorus levels. TSI measures range from a scale 20-80 and from Oligotrophic waters (maximum transparency, minimum chlorophyll-a, minimum phosphorus) through Mesotrophic, Eutrophic, to Hypereutrophic waters (minimum transparency, maximum chlorophyll-a, maximum phosphorus). Also referred to as the (Mean) Trophic State Index (TSI). Also see Total Inorganic Nitrogen (TIN) and Total Inorganic Phosphate (TIP). CARNIVORE—An organism that feeds primarily on other animals. CARNIVOROUS—Flesh eating organisms. CARP—A fresh water fish that sometimes lives in schools in lakes. Sometimes used for food. CARR, also CAR—(1) A pool; also, a Fen or a Bog. (2) The yellow or brown sediment of humate of iron in water flowing from a peaty bog. CARRIAGE LOSSES (Water)—A term used to describe the operational losses associated with conveying water from its point of diversion to its point of use. These losses typically include spillage, seepage, evaporation, and phreatophyte usage along the water course, as applicable. Water rights applicants are entitled to water for transporting their entitlement to their proposed place(s) of use. Carriage losses are generally considered unavoidable, and are legally bearable so long as that extra water is used reasonably and economically in transporting the water to its destination.
CARRYING CAPACITY—(Biologic) The carrying capacity of a lake refers to its natural productivity. In relation to fish production, or other aquatic life, the numbers which the natural food supply, or pasturage, will support adequately. CARRYING CAPACITY—(Commercial) The measure of the capacity of a lake for boating, skiing, bathing - recreational use in general - and residential occupation of the shore and shore border land without patent overcrowding, pollution and consequent danger to health and safety. Carrying capacity may be greatly limited if a single use is given priority; also it may be expanded if the surface area of the lake is zoned for particular uses and the time for use in each zone is specified. Some of the factors involved in determining carrying capacity: size, shape, depth, character and location of swimming areas and beaches, regulatory and zoning restrictions, season of year, accessibility (public or private), available services (boat liveries, marinas), level of pollution or smirchment, parking facilities, usable frontage and fish (abundance, species). CARRYING CAPACITY—(Ecology) The maximum number and type of species which a particular habitat or environment can support without detrimental effects. CARRYING CAPACITY—(Lake) The amount of human development that can occur in the lake's watershed without causing a significant change in its water quality. CARRYING PLACES—Land portaged in navigation of lakes and streams, and legally a part of the navigation route. CASCADE—A short, steep drop in stream bed elevation often marked by boulders and agitated white water. CASCADE FLOW —Regulated flow through a series of flow control structures. CASING—The steel conduit required to prevent waste and contamination of the ground water and to hold the formation open during the construction or use of the well. A tubular structure intended to be water tight 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.
CASUAL WATER—A temporary accumulation of water not forming a regular hazard of a golf course. CAT ICE—"Ice forming a thin shell from under which the water has receded." (Navigation Dictionary USHO, Bulletin 220, 1956) The term has some application to ice on lakes. CATABOLISM—The biological breakdown of materials into their simpler components, i.e., decomposition. Performed by decomposer organisms, mainly bacteria and fungi. CATADROMOUS—Used to describe fish that live in fresh water but migrate to marine waters to breed. Contrast with Anadromous. CATALASE—A red crystalline enzyme that consists of a protein complex with hematin groups and catalyzes the decomposition of Hydrogen Peroxide into water and oxygen. CATALYSIS—The action of a Catalyst, especially an increase in the rate of a chemical reaction. CATALYST—A substance that alters the speed of a reaction, but does not change the form or amount of product. For example, Enzymes are biological catalysts, enhancing reactions within living organisms. CATALYTIC CONVERTER—A reaction chamber typically containing a finely divided platinum-iridium Catalyst into which exhaust gases from an automotive engine are passed together with excess air so that carbon monoxide and hydrocarbon pollutants are oxidized to carbon dioxide and water. CATALYZE—To modify, especially to increase, the rate of a chemical reaction by Catalysis or the action of a Catalyst. CATAPHORESIS—The migration of charged colloidal particles (Colloids) or Molecules through a solution under the influence of an applied electric field usually provided by immersed electrodes. Also call Electrophoresis.
CATCH BASIN—A sieve-like device at the entrance to a sewer to stop matter that could possibly block up the sewer. CATCHMENT—(1) The catching or collecting of water, especially rainfall. (2) A reservoir or other basin for catching water. (3) The water thus caught. CATCHMENT AREA—(1) The intake area of an aquifer and all areas that contribute surface water to the intake area. (2) The areas tributary to a lake, stream, sewer, or drain. (3) A reservoir or basin developed for flood control or water management for livestock and/or wildlife. See also Drainage Area; Watershed. (4) The land (and including the streams, rivers, wetlands and lakes) from which water runs off to supply a particular location in a freshwater system. In North America, the term watershed is often used instead of catchment area. In the UK, watershed means the line separating two adjacent catchments. CATCHMENT AREA (BASIN)—The area draining into a river, reservoir, or other body of water. CATCHMENT BASIN—The entire area from which drainage is received by a river or a lake; most generally used in reference to surface runoff. CATEGORICAL EXCLUSION—A class of actions which either individually or cumulatively would not have a significant effect on the human environment and therefore would not require preparation of an Environmental Assessment (EA) or an Environmental Impact Statement (EIS) under the National Environmental Policy Act (NEPA). CATEGORICAL PRETREATMENT STANDARD—A technology-based effluent limitation for an industrial facility discharging into a municipal sewer system. Analogous in stringency to Best Available Technology (BAT) for direct dischargers. CATEGORICAL VARIABLE—(Statistics) A qualitative variable created by classifying observations into categories. For example, a series of household incomes could be classified into the categorical variables low, medium, and high describing certain specific ranges of income levels. Many statistical techniques are inappropriate for the use of categorical variables. Also referred to as a Qualitative Variable. Contrast with Quantitative Variable.
CATFISH—A fish found in freshwater rivers and has long feelers around its mouth. Often used as food. CATHOLE—A localism used by early settlers in southern Michigan for very small (usually less than an acre) shallow depressions or holes. The name presumably originated from the characteristic aquatic plant, the cattail, (Typha spp.). Later, the term came to be applied loosely to any shallow boggy or miry depression especially in the till clay plains. These depressions represented minor inequalities in the plains left by the ice sheet and were originally numerous but have been largely obliterated by land clearing and land drainage. The term cathole is also an old colloquialism for a hole or pond, in a stream, or swamp, frequented by catfish. CATION—The positively charged particle or ion in an electrolyzed solution which travels to the cathode and is there discharged, evolved, or deposited. Also, by extension, any positive ion. The common cations present in lakes in normal order of decreasing concentrations follows: calcium (Ca++), magnesium (MG++), potassium (K+), sodium (Na+), ammonium (NH4+), ferric iron (FE+++), or ferrous iron (FE++), manganese (Mn++), and hydrogen (H+). CATION EXCHANGE—A chemical process in which Cations of like charge are exchanged equally between a solid, such as zeolite, and a solution, such as water. The process is often used to soften water. CATION EXCHANGE CAPACITY (CEC)—The total of exchangeable cations that a soil can adsorb; expressed in milliequivalents per 100 grams (g) of soil. CAT'S-PAW, also Catspaw—A light breeze that ruffles small areas of a water surface. CATTAIL—A tall, reedy marsh plant with brown furry fruiting spikes; an Emergent Plant. CAUSEWAY—A raised roadway formed by filling across wet or marshy ground, or the surface of a lake from shore to shore. CAUSTIC—Alkaline or basic.
CAVE-IN LAKES—Kettle lakes, sink lakes, thaw lakes, thermo-karst. CAVENDISH, Henry (1731-1810)—A British chemist and physicist who discovered the properties of hydrogen and established that water was a compound of hydrogen and oxygen. CAVERN—A large underground opening in rock (usually limestone) which occurred when some of the rock was dissolved by water. In some igneous (formed by volcanic action) rocks, caverns can be formed by large gas bubbles. CAVITATION—(1) A process of erosion in a stream channel caused by sudden collapse of vapor bubbles against the channel wall. (2) The formation of cavities filled with air and water vapor due to internal pressure reduced below atmosphere. (3) The formation and collapse of gas pockets or bubbles on the blade of an impeller or the gate of a valve; collapse of these pockets or bubbles drives water with such force that it can cause pitting of the gate or valve surface. CCE—Carbon - Chloroform Extract CDI—Capacitive Deionization CE-QUAL-ICM—Three-dimensional, time variable, integrated-compartment eutrophication model. CE-QUAL-RIV—Hydrodynamic and water quality model for streams. CE-QUAL-WZ—Two-dimensional, laterally averaged hydrodynamic and water quality model. CEAM—Center for Exposure Assessment Modeling. CEC—Cation Exchange Capacity CELL—(Biology) The basic building block of all living matter. The cell of a living organism contains a high percentage of water. CELLULAR—Made up of small compartments. CELLULOSE—The fibrous part of plants used in making paper and textiles, which in turn may be made into building products.
CELSIUS [Temperature Scale] (C)—(1) Relating to, conforming to, or having the international thermometric scale on which the interval between the triple point of water and the boiling point of water is divided into 99.99 degrees with 0.01 representing the Triple Point and 100 the boiling point at one atmosphere of pressure; Abbreviation C; Compare to Centigrade [Temperature Scale]. The Celsius scale, which is identical to the centigrade scale, is named for the 18th-century Swedish astronomer Anders Celsius, who first proposed the use of a scale in which the interval between the freezing and boiling points of water is divided into 100 degrees. By international agreement, the term Celsius has officially replaced Centigrade. (2) Unit of measure for the Centigrade Temperature Scale of measuring temperature, as contrasted with the Fahrenheit unit of measure. The formula for converting a Celsius temperature to Fahrenheit temperature is °F = [9/5°C + 32]. Also see Temperature Scale. CENOZOIC—Of, belonging to, or designating the latest era of geologic time, which includes the Tertiary Period and the Quaternary Period and is characterized by the formation of modern continents, glaciation, and the diversification of mammals, birds, and plants. CENSUS—A complete counting, with classification, of a population or group at a particular point in time, as regards to some well-defined characteristic(s). Usually has governmental and economic and social connotations, e.g., the decennial census of the population; however, also used in a biological and environmental sense for plants, animals, and habitat. CENSUS OF AGRICULTURE—A Census taken by the U.S. Department of Commerce, Bureau of the Census, every 5 years to include the number of farms, land in farms, crop acreage and production, irrigated acreage, farm spending, farm facilities and equipment, farm tenure, value of farm products sold, farm size, and other farm-related data. CENSUS X-11 (Seasonal Adjustment) PROCESS—(Statistics) A seasonal adjustment process for decomposing time series data into its trend-level, seasonal index, trading day, and irregular components. It is primarily used to De-Seasonalize official government statistics for publication, but is arguably the most widely used and accepted seasonal adjusted process.
CENTER-PIVOT IRRIGATION—Automated sprinkler irrigation achieved by automatically rotating the sprinkler pipe or boom, supplying water to the sprinkler heads or nozzles, at a radius from the center of the field to be irrigated. Water is delivered to the center or pivot point of the system. The pipe is supported above the crop by towers at fixed spacing and propelled by pneumatic, mechanical, hydraulic, or electric power on wheels or skids in fixed circular paths at uniform angular speeds. Water is applied at a uniform rate by progressive increase of nozzle size from the pivot to the end of the line. The depth of water applied is determined by the rate of travel of the system. Single units are ordinarily about 1,250 to 1,300 feet long (381-397 meters) and irrigate approximately a 130-acre (52.7 hectare) circular area. Also see Irrigation Systems. CENTIGRADE [Temperature Scale] (C)—Relating to, conforming to, or having a thermometric scale on which the interval between the freezing point of water and the boiling point of water is divided into 100 degrees with 0 representing the freezing point and 100 the boiling point at one atmosphere of pressure; Abbreviation C; Compare to Celsius [Temperature Scale]. The Centigrade scale is identical to the Celsius scale; however, by international agreement, the term Celsius has officially replaced Centigrade. Contrast with the Fahrenheit Temperature Scale, using degrees Fahrenheit (F), in which 32°F above the 0(°F) mark indicates the freezing point of water and 212°F indicates the boiling point of water (at sea level). Also see Temperature Scale. CENTRAL VALLEY PROJECT (CVP) [California]—A multipurpose water project developed mainly by the U.S. Bureau of Reclamation (USBR), extending from the Cascade Range on the north to the semiarid but fertile plains of California's Kern River on the south. The state and federal portions of the Central Valley Project (CVP) encompass a number of dams, reservoirs, pumping facilities, canals, and aqueducts providing protection from saltwater intrusion into the Bay-Delta region (also referred to as the Sacramento-San Joaquin Delta), irrigation water for San Joaquin Valley farms, and municipal and industrial water for some of California's most populated urban areas. The construction of the CVP was approved by California voters in a 1933 referendum of the California Central Valley Project Act. Due to the effects of the Great Depression, the state was unable to construct the project at that time. Subsequently, portions of the CVP were authorized and constructed by the federal government. Other portions were later constructed by California after the Depression as part of the State Water Project (SWP), as authorized under the 1960 Burns-Porter Act. Principal facilities of the SWP include Oroville Dam, Delta Facilities, the California Aqueduct, and North and South Bay Aqueducts. Principle facilities of the federal CVP include Shasta, Trinity, Folsom, Friant, Clair Engle, Whiskeytown, and New Melones dams, Delta facilities, and the Delta Mendota Canal. Joint CVP/SWP facilities include San Luis Reservoir and Canal and various Delta facilities. Also see Bay-Delta [California].
CENTRALIZED CONTROL (Canal)—Control of a canal project from a central location by the watermaster. CENTRALIZED HEADQUARTERS (Canal)— Control of a canal project from a central location generally by a master station, communications network, and one or more remote terminal units (RTUs). CENTRIFUGAL PUMP—A device that converts mechanical energy to pressure or kinetic energy in a fluid by imparting centrifugal force on the fluid through a rapidly rotating impeller. CENTRIFUGATION—(Water Quality) In water and wastewater treatment, a method used to remove liquid from sludge through use of centrifugal forces. CEQA—See California Environmental Quality Act (CEQA). CERCLA—See Comprehensive Environmental Response, Compensation, and Liability Act. CERES—California Environmental Resources Evaluation System CERTIFICATE OF WATER RIGHT—An official document which serves as evidence of a Perfected Water Right. Also see Application, Water Right. CERTIFICATED WATER RIGHT—The right granted by a state water agency to use either surface or ground water. Also see Application, Water Right and Vested Water Right. CERTIFICATED WATER RIGHT [Nevada]—The right to put surface or ground water to beneficial use that is identified by a recorded document issued by the Nevada State Engineer after satisfactory proof of "perfection of application" for a permitted water right has been filed in accordance with Nevada Revised Statues Chapter 533. CERTIFIED WATER RIGHT—A state-issued document that serves as legal evidence that an approved application has been physically developed and the water put to beneficial use. The certificate establishes priority date, type of beneficial use, and the maximum amount of water that can be used. Before a water right can be certified, verification of the physical development must be provided to the state through a survey conducted by an approved water rights examiner. Even certified water rights are subject to occasional review to ensure continued beneficial use.
CESSPOOL—An underground catch basin for combined liquid and solid waste, such as household sewage, so designed as to retain the organic matter and solids but permitting the liquids to seep through the bottom and sides. Also see Septic Tanks. CF—Cubic Feet (or Foot). CFCs—Chlorofluorocarbons. CFR—Code of Federal Regulations. CFS (Cubic Foot per Second)—A unit of discharge for measurement of flowing liquid (usually water in a stream) equal to a flow of one cubic foot per second past a given section. A rate of flow equivalent to 448.83 gallons per minute. Also called Second-Foot. CFS-DAY—The volume of water represented by a flow of 1 cubic foot per second for 24 hours. It equals 86,400 cubic feet, 1.983471 acre-feet, or 646,317 gallons. CFSM (Cubic Feet per Second per Square Mile)—The average number of cubic feet of water per second flowing from each square mile of area drained by a stream, assuming that the runoff is distributed uniformly in time and area. CHAIN OF LAKES—A number of lakes tied together by live connecting streams or natural channels. CHALK—A mineral composed mainly of the calcareous shells of various marine microorganisms, but whose matrix consists of fine particles of calcium carbonate, some of which may have been chemically precipitated. CHALYBEATE—Tasting like iron, as water from a mineral spring. CHANNEL (LAKE)—In instances sub-lacustrine channels appear where a lake has been formed by the submergence of a valley, or the drowning of a river; the channels formed under subaerial conditions by stream cutting may remain unfilled by sediments, on the lake bottom. Channel is applied to a surface water way, either natural or artificial, which connects two lakes and provides for boat travel; to river distributaries and connecting water in a delta; and to trench-like excavations extended inland from a lake shoreline to provide water frontages and boat access for back lots.
CHANNEL (LAKE BASIN)—The deeper, narrow elogated or more sharply trenched part of a lake bottom. CHANNEL (WATERCOURSE)—A natural stream that conveys water; a ditch or channel excavated for the flow of water. River, creek, run, branch, anabranch, and tributary are some of the terms used to describe natural channels, which may be single or braided. Canal, aqueduct, and floodway are some of the terms used to describe artificial (man-made) channels. CHANNEL BANK—The sloping land bordering a channel. The bank has steeper slope than the bottom of the channel and is usually steeper than the land surrounding the channel. CHANNEL CAPACITY—The maximum rate of flow that may occur in a stream without causing overbank flooding. CHANNEL CONTROL—The condition under which the stage-discharge relation of a gaging station is governed by the slope, size, geometry, and roughness of the channel. CHANNEL DENSITY—The ratio of the length of stream channels in a given basin to the area of the basin, expressed in feet per acre (meters per hectare). CHANNEL INFLOW—Water which at any instant is flowing into the channel system from surface flow, subsurface flow, base flow, and rainfall directly on the channel. CHANNEL LINING—Protection of the channel bottom and banks with concrete or Riprap. CHANNEL MODIFICATION—The modification of the flow characteristics of a channel by clearing, excavation, realignment, lining, or other means to increase its capacity. Sometimes the term is used to connote Channel Stabilization. CHANNEL REALIGNMENT—The construction of a new channel or a new alignment which may include the clearing, snagging, widening, and/or deepening of the existing channel. CHANNEL STABILIZATION—Erosion prevention and stabilization of velocity distribution in a channel using jetties, drops, revetments, vegetation, and other measures.
CHANNEL STORAGE—The volume of water at a given time in the channel or over the flood plain of the streams in a drainage basin or river reach. Channel storage is sometimes significant during the progress of a flood event. CHANNELED—Having one or more longitudinal grooves. CHANNELIZATION—The artificial enlargement or realignment of a stream channel. CHAOS THEORY—A modern development in mathematics and science that provides a framework for understanding irregular or erratic fluctuations in nature. Chaotic systems are found in many fields of science and engineering. Evidence of chaos occurs in models and experiments describing convection and mixing in fluids, in wave motion, in oscillating chemical reactions, and in electrical currents in semiconductors. It is also found in the dynamics of animal populations and attempts are being made to apply chaotic dynamics in the social sciences, such as the study of business cycles. A chaotic system is defined as one that shows "sensitivity to initial conditions." That is, any uncertainty in the initial state of the given system, no matter how small, will lead to rapidly growing errors in any effort to predict its future behavior. This "sensitivity to initial conditions" will make any long-term prediction of such phenomenon virtually impossible in reality. In other words, the system is chaotic and as such its behavior can be predicted only if the initial conditions are known to an infinite degree of accuracy, which is impossible. The possibility of chaos in a natural, or deterministic, system was first envisaged by the French mathematician Henri Poincare in the late 19th century. More recently, predictions have been made that the transition to chaotic turbulence in a moving fluid would take place at a well-defined critical value of the fluid's velocity (or some other important factor controlling the fluid's behavior). The term chaotic dynamics refers only to the evolution of a system in time. Chaotic systems, however, also often display spatial disorder—for example, in complicated fluid flows. CHAPARRAL—A type of Biome with hot, dry summers and rainfall mainly in the winter months. Vegetation consists of shrubs, small evergreen trees, and sclerophyllous species. Chaparral communities are found around the Mediterranean Sea, in central and southern California, along coastal Chile, in southern Australia, and in southern Africa. CHARA—Muskgrasses or stoneworts - An unusual type of algae that has a grown form resembling a higher plant, but a close look reveals each joint of the stem is a single cell with no connective tissue. CHAROPHYTES—A group of green algae, visible to the naked eye, with a characteristic structure in which the 'stems' are very large single cells, from which whorls of similarly constructed branches emerge. Charophytes are anchored in sediments by branching cellular systems, not roots. They often deposit marl (calcium carbonate) giving them a rough texture and the common name of 'stoneworts', though not all do this. They also have a characteristic smell, which some people describe as 'garlicky'. CHASM—Sometimes water filled, deep crack or opening in the earth's surface. CHATTER MARK, also Chattermark —(Geology) One of a series of short scars made by glacial drift on a surface of bedrock. CHECK DAM—A small dam constructed in a gully or other small watercourse to decrease the streamflow velocity, minimize channel erosion, promote deposition of sediment, and to divert water from a channel. CHECK GATE—A gate located at a check structure used to control flow.
CHECK IRRIGATION—A method of irrigation in which an area is practically or entirely surrounded by earth ridges. CHEMICAL—A substance made by chemistry. Oxidation is a chemical process in which iron combines with oxygen, commonly called rusting. CHEMICAL EFFLUENTS—Non-natural liquids or emulsions discharged to a stream or lake. CHEMICAL FEEDER—(Water Quality) A mechanical device for measuring quantities of chemical and applying them to a water at a preset rate. CHEMICAL OXYGEN DEMAND (COD)—(Water Quality) A chemical measure of the amount of organic substances in water or wastewater. A strong oxidizing agent together with acid and heat are used to oxidize all carbon compounds in a water sample. Non-biodegradable and recalcitrant (slowly degrading) compounds, which are not detected by the test for Biochemical Oxygen Demand (BOD), are included in the analysis. The actual measurement involves a determination of the amount of oxidizing agent (typically, potassium dichromate) that is reduced during the reaction. Also see Total Carbon (TC) and Total Organic Carbon (TOC). CHEMICAL PARAMETERS—The constituent chemicals found in a sample of a media, such as water. CHEMICAL WEATHERING—The gradual decomposition of rock by exposure to rainwater, surface water, atmospheric oxygen, carbon dioxide and other gases in the atmosphere, as well as compounds secreted by organisms. Compare to Physical Weathering. CHEMIGATION—Application of pesticides or fertilizers to farmlands through irrigation systems. CHEMIST—A person who specializes or works in chemistry. CHEMISTRY—The science of substances. It describes their characteristics, catalogs them and determines what happens when they are combine together and react.
CHEMOAUTOTROPH—An organism that utilizes oxidation of inorganic chemicals for its energy and carbon dioxide for cell growth. Also called a Chemosynthetic Autroph. CHEMOCLINE—(1) The transition zone between layers in a Meromictic Lake. Here the density is usually controlled more with what is dissolved in the water than the temperature of a fluid. (2) The boundary between mixolimnion and monolimnion. The density gradient of a lake. CHEMODYNAMICS—The study of the transport, conversion, and fate of chemical substances in air, water, or soil, including their movement from one medium to another. CHEMOSPHERE—The region of the upper Atmosphere including the Mesosphere and upper Stratosphere in which various sunlight-driven chemical reactions occur. CHEMOSYNTHESIS—The synthesis of carbohydrate from carbon dioxide and water using energy obtained from the chemical oxidation of simple inorganic compounds. This form of synthesis is limited to certain bacteria and fungi. CHILILE—Inshore lake bottom. CHIMNEY—A tall column of rock on the ocean floor that is formed by the precipitation of minerals from superheated water issuing from a vent in the earth's crust and rising through the column of rock. Also see Black Smoker. CHINOOK—A downslope wind in which the air is warmed by adiabatic (gradual) heating. Such conditions describe a warm, dry southwest wind blowing from the sea onto the coast of Oregon and Washington in the winter and spring, as well as a warm, dry wind blowing down the eastern slope of the Rocky Mountains. CHLORAMINES—Compounds containing nitrogen, hydrogen, and chlorine, formed by the reaction between hypochlorous acid (HOCl) and ammonia (NH3) and/or organic amines in water. The formation of chloramines in drinking water treatment extends the disinfecting power of chlorine. Also referred to as Combined Available Chlorine. CHLORIDES—Negative chlorine ions, Cl-, found naturally in some surface waters and groundwaters and in high concentrations in seawater. Higher-than-normal chloride concentrations in fresh water, due to sodium chloride (table salt) that is used on foods and present in body wastes, can indicate sewage pollution. The use of highway deicing salts can also introduce chlorides to surface water or groundwater. Elevated groundwater chlorides in drinking water wells near coastlines may indicate Saltwater Intrusion.
CHLORINATED—(Water Quality) Describes water or wastewater that has been treated with either chlorine gas or a chlorine-containing compound. CHLORINATED HYDROCARBONS—(Water Quality) Includes a class of persistent, broad-spectrum insecticides that linger in the environment and accumulate in the food chain. Among them are DDT, aldrin, diedrin, heptachlor, chlordane, lindane, endrine, mirex, hexachloride, and toxaphene. CHLORINATION—The application of chlorine or one of its compounds to water or wastewater, often for disinfection or oxidation purposes. CHLORINATOR—A device for adding a chlorine-containing gas or liquid to drinking water or wastewater. CHLORINE—One of a group of elements classified as the halogens. Chlorine, Cl2, the most common halogen, is a greenish yellow gas with an irritating odor. Chlorine is very reactive; it forms salts with metals, forms acids when dissolved in water, and combines readily with hydrocarbons. Various forms of chlorine are used to disinfect water. Chlorine is produced by the electrolysis of brine (a concentrated salt solution). Atomic number 17; atomic weight 35.45; freezing point -100.98°C; boiling point -34.6°C; specific gravity 1.56 (-33.6°C). CHLORINE BREAKPOINT—(Water Treatment) The point at which the chlorine dosage in a water treatment process has satisfied the Chlorine Demand. To eliminate the taste and odor associated with processed water, sufficient chlorine must be added to reach the breakpoint. Increasing the chlorine dose beyond the breakpoint produces a free chlorine residual, which is free to kill microorganisms. When chlorine is added to water, it first combines with constituents in the water such as iron, manganese, and nitrites. It is important to add enough chlorine to the water initially to ensure that these constituents are oxidized and to ensure that a residual is formed to react with the ammonia and organic matter in the water. Taste and odor problems result when chlorine dosages are either below the breakpoint, or well beyond the breakpoint. CHLORINE-CONTACT CHAMBER—(Water Quality) In a wastewater treatment plant, a chamber in which effluent is disinfected by chlorine before it is discharged to the receiving waters. CHLORINE DEMAND—(Water Quality) The amount of chlorine that must be added to purify drinking water; the amount of chlorine required to react with all dissolved and particulate materials and inorganic ammonia in the water. CHLORINE RESIDUAL—The concentration of chlorine remaining in water or wastewater at the end of a specified contact period which will react chemically and biologically. May be present as either combined or free chlorine, or both. CHLOROPHYLL—(1) The green pigments of plants. There are seven known types of chlorophyll, Chlorophyll a and Chlorophyll b are the two most common forms. A green photosynthetic coloring matter of plants found in chloroplasts and made up chiefly of a blue-black ester. (2) Major light gathering pigment of all photosynthetic organisms and is essential for the process of photosynthesis. The amount present in lake water depends on the amount of algae and is therefore used as an common indicator of water quality. CHLOROPHYLL MAPPING—Showing the variation of chlorophyll over the surface of a water body on a map.
CHOLERA—An infectious waterborne disease that is characterized by severe diarrhea and its resultant dehydration and electrolyte imbalance. The disease is caused by bacteria belonging to the genus Vibrio. Outbreaks are associated with contamination of surface waters with human fecal material. CHOLOPHYTE—Green algae, algae of the division Chlorophyta. CHOP—A short, irregular motion of waves. Also, an area of choppy water, as on an ocean. CHOTT, also Shott—(1) The depression surrounding a salt marsh or lake, especially in North Africa. (2) The bed of a dried salt marsh. CHRESARD—Water present in the soil and available for plant absorption. CHRONIC—Showing effects only over a long period of time, as in chronic toxicity. CHRYSOPHYTE—Golden or yellow-green algae, algae of the division Chrysophyta. CHUCKHOLE—A rough hole in pavement, made by wear and weathering, more commonly referred to as Pothole. CHUTE, or CHUTE CUTOFF—As applied to stream flow, the term "chute" refers to a new route taken by a stream when its main flow is diverted to the inside of a bend, along a trough between low ridges formed by deposition on the inside of the bend where water velocities were reduced. Compare with Neck Cutoff. CHUTE SPILLWAY—The overfall structure which allows water to drop rapidly through an open channel without causing erosion. Usually constructed near the edge of dams. CIR—Consumptive Irrigation Requirement/Crop Irrigation Requirement. CIRCULATE, or CIRCULATION—Movement or passage through a system of vessels, as water through pipes.
CIRCUMNEUTRAL—Term applied to water with a pH of 5.5 (acidic) to 7.4 (alkaline). CIRQUE—A smallish, rounded depression with steeply sloping sides carved into the rock at the top of a ridge where a glacier has its head. After the period of glaciation ends, the cirque may contain a small remnant of the former glacier, or it may fill with water and become a lake. The term Tarn is also used to describe lakes that have formed in cirques. CIRQUE BASIN—A half-amphitheater formed by alpine Glaciation with three steep sides. Usually found at upper ends of valleys and along ridges. CIRQUE LAKE—A lake occupying a rock basin usually at the head of a valley in high mountain ranges. CIRROCUMULUS CLOUDS—A high-altitude cloud composed of a series of small, regularly arranged cloudlets in the form of ripples or grains. Also see Cloud. CIRROSTRATUS CLOUDS—A high-altitude, thin hazy cloud, usually covering the sky and often producing a halo effect. Also see Cloud. CIRRUS CLOUDS—A principal cloud type found at high altitudes and composed of ice crystals collected into delicate wisps or patches. Also see Cloud. CISTERN—An artificial reservoir or tank used for holding or storing water or other liquids. Typically a tank, often underground, used for storing rain water collected from a roof. CLADOCERA—Water fleas. A group of crustaceans up to a few millimeters long, which either filter particles from water for food or grasp larger particles such as smaller animals. The best known genus is Daphnia. CLAM—A mollusk with a hinged shell in two parts(bi-valve) and a soft body. An filter feeder in flowing fresh and salt waters. CLAM-FLAT—(New England) A level stretch of soft tidal mud where clams burrow. CLAMMY—(1) Disagreeably moist, sticky, and cold to the touch. (2) Damp and unpleasant. CLARIFICATION—A process or combination of processes where the primary purpose is to reduce the concentration of suspended matter in a liquid. CLARIFIER—A device or tank in which wastewater is held to allow the settling of particulate matter. CLARITY—The transparency of a water column. Measured with a Secchi disc. CLASS A PAN—The U.S. Weather Bureau evaporation pan is a cylindrical container fabricate of galvanized iron or monel metal with a depth of 10 inches and a diameter of 48 inches. The pan is placed on an open 2- X 4-inch wooden platform with the top of the pan about 41 cm (16 inches) above the soil surface. It is accurately leveled at a site that is nearly flat, well sodded, and free from obstructions. The pan is filled with water to a depth of eight inches, and periodic measurements are made of the changes of the water level with the aid of a hook gage set in the still well. When the water level drops to seven inches, the pan is refilled. Its average pan coefficient is about 0.7 for lake evaporation.
(INJECTION WELL) CLASSES—Classifications of the U.S. Environmental Protection Agency (EPA) that determine the permit requirements of an Injection Well. The following classes apply:
CLASSICAL INFERENCE—(Statistics) Statistical inference is based on two basic premises: (1) The sample data constitute the only relevant information; and (2) The construction and assessment of the different procedures for inference are based on long-run behavior under essentially similar circumstances. Also see Statistical Inference and Bayesian Inference. CLASSICAL LINEAR REGRESSION (CLR) MODEL—(Statistics) The standard for the Ordinary Least Squares (OLS), or Regression Analysis model. The CLR Model has five basic assumptions:
CLASSIFICATION—(Soils)The systematic arrangement of soils into groups or categories on the basis of their characteristics. Broad groupings are made on the basis of general characteristics and subdivisions on the basis of more detailed differences in specific properties. Soil Taxonomy is the study of soil classification systems. (Lakes) Grouping by similar water quality. For a description of soil classifications, see Land Capability Classes. CLASTIC—Pertaining to a rock or sediment composed principally of broken fragments that are derived from pre-existing rocks or minerals and that have been transported some distance from their places of origin. CLAY—(1a) A fine-grained, firm earth material that is plastic when wet and hardens when heated, consisting primarily of hydrated silicates of aluminum and widely used in making bricks, tiles, and pottery; (1b) A hardening or non-hardening material having a consistency similar to clay and used for modeling. (2) (Geology) A sedimentary material with grains smaller than 0.2 millimeters in diameter. (3) Moist, sticky earth; mud. CLAY LINER—A layer of clay soil that is added to the bottom and sides of a pit designed for use as a disposal site for potentially dangerous wastes. The clay prevents or reduces the migration of liquids from the disposal site. CLAYBALLS—Both small and fairly large chunks of clay rounded by wave action. These are occasionally observed on Michigan beaches, especially a narrow strand bordered by steep clay banks of hard glacial till. Also known as mud balls, armored mud balls, pudding balls. Balls of a different origin, aggregates from clay in suspension or in a viscous state, are also sometimes formed in the beds of lakes and rivers. CLAYBANKS (LAKESHORE)—Term applied to lake bluffs, or cliffs, composed almost entirely of till clay or glacial lacustrine clay. CLAYPAN—(1) A dense, compact layer in the subsoil having a much higher clay content than the overlying material from which it is separated by a sharply defined boundary. Such layers are formed by the downward movement of clay or by synthesis of clay in place during soil formation. Claypans are usually hard when dry, and plastic and sticky when wet. They usually impede movement of water and air, and the growth of plant roots. (2) (Australian) A shallow depression in which water collects after rain. Also see Hardpan.
CLAYSEAL—A barrier constructed of impermeable clay that stops the flow of water or gas. CLEAN (Water)—Water that is free from foreign matter or pollution; not infected; unadulterated. CLEAN LAKES PROGRAM—Federal program evolved from Section 314 of the Clean Water Act. CLEAN WATER ACT (CWA) [Public Law 92-500]—More formally referred to as the Federal Water Pollution Control Act, the Clean Water Act constitutes the basic federal water pollution control statute for the United States. Originally based on the Water Quality Act of 1965 which began setting water quality standards. The 1966 amendments to this act increased federal government funding for sewage treatment plants. Additional 1972 amendments established a goal of zero toxic discharges and "fishable" and "swimmable" surface waters. Enforceable provisions of the CWA include technology-based effluent standards for point sources of pollution, a state-run control program for nonpoint pollution sources, a construction grants program to build or upgrade municipal sewage treatment plants, a regulatory system for spills of oil and other hazardous wastes, and a Wetlands preservation program (Section 404). CLEAN WATER ACT (CWA), SECTION 319—A federal grant program added by Congress to the CWA in 1987 and managed by the U.S. Environmental Protection Agency (EPA), Section 319 is specifically designed to develop and implement state Nonpoint Source (NPS) Pollution management programs, and to maximize the focus of such programs on a watershed or waterbasin basis with each state. Today, all 50 states and U.S. territories receive Section 319 grand funds and are encouraged to use the funding to conduct nonpoint source assessments and revise and strengthen their nonpoint source management programs.
CLEAN WATER STANDARDS (EPA)—Generally refers to any enforceable limitation, control, condition, prohibition, standard, or other requirement which is promulgated pursuant to the Federal Water Pollution Control Act (Clean Water Act) [Public Law 92-500] or contained in a permit issued to a discharger by the U.S. Environmental Protection Agency (EPA) or by a state under an approved program, as authorized by Section 402 of the Clean Water Act, or by local governments to ensure compliance with pretreatment regulations as required by Section 307 of the Clean Water Act. CLEAR WELL—A reservoir containing potable water which has been previously treated before entering the distribution lines. CLEPSYDRA—An ancient device that measured time by marking the regulated flow of water through a small opening. Also referred to as a Water Clock or Water Glass. CLIFF—Steep, vertical or overhanging rock faces. Provide physical protection for wildlife and concentrate a variety of reptiles, birds and mammals into relatively small but stable environments. CLIFF (LAKESHORE)—Often used interchangeably with bank and bluff, in technical descriptions cliff is preferred for the wave-cut nearly vertical acclivity or abrupt slope which borders the waterline, or marks the position of the present or former shore lines of lakes. CLIMATE—The sum total of the 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. The collective state of the atmosphere at a given place or over a given area within a specified period of time. Compare to Weather. Basic types of climates include:
CLIMATIC CYCLE—The periodic changes of climate, including a series of dry years following a series of years with heavy rainfall. CLIMATIC YEAR—A period used in meteorological measurements. A continuous 12-month period during which a complete annual cycle occurs, arbitrarily selected for the presentation of data relative to hydrologic or meteorologic phenomena. The climatic year in the United States begins on October 1st and runs through September 30th. Similar to a Water Year. CLIMATOLOGY, also Climatological—The science and study dealing with climate and climatic phenomena as exhibited by temperature, winds, and precipitation.
CLIMAX—The final stage of vegetation succession; a climax community reproduces itself and is in equilibrium with the existing environment. CLOD—A compact, coherent mass of soil ranging in size from 5 to 10 millimeters (0.20 to 0.39 inch) to as much as 200 to 250 millimeters (7.87 to 9.84 inches) produced artificially, usually by the activity of man by plowing, digging, etc., especially when these operations are performed on soils that are either too wet or too dry for normal tillage operations. CLOSED BASIN—A basin is considered closed with respect to surface flow if its topography prevents the occurrence of visible surface outflow. It is closed hydrologically if neither surface nor underground outflow can occur. CLOSED-BASIN LAKE—A lake which has no outlet, from which water escapes only by evaporation. CLOSED CANOPY—Forest trees dense enough that tree crowns fill or nearly fill the canopy layer. CLOSED CONDUIT SYSTEM—A conveyance system where the flow of water is confined on all boundaries (i.e., pipe systems). CLOSED-CYCLE COOLING—A process in which cooling water used in industrial processes or in the generation of electrical energy is not discharged into receiving streams, where direct discharge can have adverse effects, but is circulated through cooling towers, evaporators, ponds, or canals to allow the dissipation of the heat, and the water to be reused. CLOSED DRAIN—Subsurface drain, tile, or perforated pipe that receives surface water through surface inlets. CLOSED LAKES—Those that do not have an effluent in contrast to drainage lakes or open lakes which do have outlet streams. Closed lakes are common in arid and semi-arid regions where they usually contain saline or brackish water. CLOSED-LOOP RECYCLING—Recycling or reusing wastewater for non-potable purposes in an enclosed process. CLOSED WATER LOOP—A process in which decontaminated wastewater is not discharged into a receiving stream but is reused. Any water lost during the process through evaporation or binding with some material is replaced by makeup water. Contrast with Open Water Loop. CLOSET—A water closet; a toilet.
CLOUD—A cloud is any concentration of gas, liquid droplets, or solid particles suspended as a distinct body in a gas or liquid. Generally, however, the term cloud is used to refer to the suspension of small ice or water particles in the Atmosphere. Cloud Formation—Clouds in the atmosphere form whenever the relative Humidity of an air mass, or parcel, reaches slightly more than 100 percent. This can occur for a number of reasons: the upward motion of air, which causes expansion and cooling; input of water from outside the parcel; or loss of heat by radiation. Among the major producers of the upward motion that results in clouds are the Low-Pressure systems with their cold, warm, and occluded Fronts; tropical disturbances such as Hurricanes, Cyclones, or Typhoons; and the lifting of air as it flows over hilly and mountainous terrain. The size of cloud droplets and ice crystals ranges from about 1 to 100 micrometers (4/100,000 to 4/1,000 in). Particles this small fall to the ground so slowly that they appear suspended in air, tending to move with the wind. The fall of larger particles, at much greater speeds, is called Precipitation. About 1 million cloud droplets, with an average radius of 10 micrometers (4/10,000 inch), are required to make a typical raindrop of 1 mm (4/100 inch). Cloud droplets can exist at temperatures below 0C (32F) and are then referred to as supercooled. When supercooled water and ice crystals occur at the same location, the ice grows at the expense of the water, and an ice cloud forms. This occurs because at a given temperature ice has a greater affinity than liquid water for water vapor. Cloud droplets and ice crystals first form on certain types of small particles of dust or other airborne materials. They are called condensation nuclei when water droplets are formed and ice nuclei when ice crystals result. The nuclei generally range in size from as small as 0.01 micrometer to about 1 micrometer (4/10,000,000 to 4/100,000 inch). The number of nuclei vary widely, depending on the source of the air mass in which the parcel is imbedded. The atmosphere over the ocean generally has the lowest number of nuclei, whereas polluted air has the highest. The more nuclei, and therefore the more water droplets or ice crystals, the slower the process of formation of precipitation-sized particles, because the competition for the available water is greater. Thus, although Rain often falls shortly after a cloud forms over the ocean, a much longer time is required over continental areas. Cloud Classification—Clouds are classed as warm if their temperature throughout is above 0C (32F) and cold if they extend to heights where temperatures are less than 0 C. Cold clouds containing both supercooled water and ice are defined as mixed clouds; clouds composed entirely of ice are said to be glaciated. Some cold clouds contain only supercooled water. These clouds are hazardous to aviation because the water, freezing on impact with an airplane, can cause ice to build up on the fuselage and wings. Clouds, defined in terms of their gross physical characteristics, can be classified as Stratiform or Cumuliform. Stratiform, or layered, clouds form when the upward motion is relatively uniform over an area, and cumuliform, or cottony, billowing clouds develop when upward and downward air currents are separated by fairly short distances. When clouds form at ground surface they are called Fog. Clouds that form in the middle Troposphere are called Altostratus and Altocumulus, and those in the upper troposphere are referred to as Cirrocumulus, Cirrostratus, or Cirrus. For those with bases in the lower troposphere, the terms Stratus and Cumulus are used. When precipitation is falling from these clouds, they are referred to with such terms as Nimbostratus or Cumulonimbus. Nimbostratus are the gray, leaden-sky clouds often produced by large-scale winter Cyclones in which precipitation is fairly steady and long-lasting. Cumulonimbus clouds, on the other hand, are associated with typical summertime Thunderstorms, in which rainfall is generally brief but heavy. A system of classifying clouds according to their physical characteristics has been devised by the World Meteorological Organization. Some of the more common cloud types are listed below:
CLOUDBURST—A sudden and extremely heavy downpour of rain that is small in areal extent, of short duration, and may be accompanied by lightening, thunder, and strong gusts of winds. Also, a torrential (hard) downpour of rain, which by its spottiness and relatively high intensity suggests the bursting and discharge of water from a cloud all at once. CLOUD CHAMBER—A vessel containing air saturated with water vapor whose sudden expansion reveals the passage of an ionizing particle by a trail of visible droplets. CLOUD MODIFICATION—Any process by which the natural course of development of a cloud is altered by artificial means. Also referred to as Weather Modification. CLOUD SEEDING—A Weather Modification technique involving the injection of a substance into a cloud for the purpose of influencing the cloud's subsequent development. Ordinarily, this refers to the injection of a nucleating agent, which creates a nucleus around which precipitation will form. In common practice, cloud seeding involves the aerial release of silver iodide particles into convective clouds to create thunderstorms. CLOUDY—(1) When the sky is covered with clouds. A cloudy sky makes for a dark and gray day. (2) Water is cloudy and not clear so we couldn't see the stream bottom. CLR—Classical Linear Regression Model. CLUSTER DEVELOPMENT—Placement of housing and other buildings of a development in groups to provide larger areas of open space between groups. CNE—Curve Number Equation. COAGULANT—(1) An agent that causes a liquid or sol to coagulate. (2) (Wastewater Treatment) A chemical compound, such as Alum (aluminum sulfate), used to produce coagulation. COAGULANT AID—(Wastewater Treatment) Fine particles with high surface area and high specific gravity providing for increased particle collisions during the neutralization process in wastewater treatment plants. They also improve settling and strengthen flocs in the coagulation process. They are generally used in much smaller doses than the coagulant itself. For example, Sodium Bicarbonate increases the efficiency of coagulation and extends the pH range to a level at which Alum (aluminum sulfate), is effective. COAGULATE—To cause the transformation of a liquid or sol, for example, into or as if into a soft, semisolid, or solid mass. COAGULATION—The clumping of particles which results in the settling of impurities. It may be induced by coagulants such as lime, alum, and iron salts. COAL SLURRY PIPELINE—A pipeline which transports pulverized coal suspended in liquid, usually water.
COAST—According to prevailing usage, the term is applied to land bordering seas. The shorelands of the Great Lakes are also called coasts. COASTAL ZONE—Coastal waters and adjacent lands that exert a measurable influence on the uses of the seas and their resources and biota. COASTAL ZONE MANAGEMENT ACT (CZMA)—A 1972 federal law, amended in 1980, that provides guidance and financial assistance to voluntary state and local coastal management programs. Goals of the program include the protection of natural resources and the management of land development in coastal areas, along shorelines, and on shorelands (extending inland as far as a strong influence on the shore is expected). The state programs established under the CZMA vary widely in their approach and application. COASTLINE—The shape or outline of a coast. COBBLE—Rock fragments 7.6 cm (3 inches) to 25.4 cm (10 inches) in diameter. COBBLESTONE PAVEMENT—See Boulder Pavement. COD—See Chemical Oxygen Demand. COD—See Cone of Depression. CODE OF FEDERAL REGULATIONS (CFR)—The annual compilation of all current regulations that have been issued in final form by any federal regulatory agency. The publication is organized by subject titles. Environmental regulations are covered under Title 40, Protection of the Environment. CO-DOMINANT—Two or more plant species providing about equal areal cover which in combination control the environment. COE—Corps of Engineers COEFFICIENT TERM—(Statistics) The weight applied to one of the Independent (or Exogenous) Variables in the best prediction of the Dependent (or Endogenous) Variable. It is interpreted as the slope of the relation between the independent variable and the dependent variable, or the change in the dependent variable for a unit change in the independent variable. COEFFICIENT OF DETERMINATION (R2)—(Statistics) A common measure of the "Goodness of Fit" in Regression Analysis used to assess the degree of causation between two variables or between one or more independent variables and a single dependent variable. The coefficient of determination is equivalent to the square of the Correlation Coefficient and reflects the percent of variation in the dependent (explained) variable that is explained by the variations in the independent (explanatory) variable(s). The value of the coefficient of determination various between 0 (0 percent) and 1 (100 percent) with higher numbers representing better explanatory powers of a model in explaining the trends in historical data.
COEFFICIENT OF DISCHARGE—The ratio of the observed to theoretical discharge. COEFFICIENT OF LINEAR EXTENSIBILITY—The ratio of the difference between the moist and dry lengths of a Clod to its dry length. The measurement correlates with the volume change of a soil upon wetting and drying. COEFFICIENT OF MECHANICAL DIFFUSION—The rate at which solutes are mechanically mixed during Advective Transport, caused by the velocity variations at the microscopic level. COEFFICIENT OF MOLECULAR DIFFUSION—(1) The rate at which solutes are transported at the microscopic level due to variations in the solute concentrations within the fluid phases. (2) The rate of dispersion of a chemical caused by the kinetic activity of the ionic or molecular constituents. Also referred to as the Diffusion Coefficient. See Molecular Diffusion. COEFFICIENT OF ROUGHNESS—Factor in fluid flow determination expressing the character of a surface and its fractional resistance to flow. Also referred to as Roughness Coefficient. COEFFICIENT OF RUNOFF—Factor in the rational runoff formula expressing the ratio of peak runoff rate to rainfall intensity. COEFFICIENT OF STORAGE—The volume of water an aquifer releases from or takes into storage per unit surface area of the aquifer per unit change in head. COEFFICIENT OF TRANSMISSIVITY (t)—The rate at which water of the prevailing kinematic viscosity is transmitted through a unit width of the aquifer under a unit Hydraulic Gradient. It is equal to an integration of the hydraulic conductivities across the saturated part of the aquifer perpendicular to the flow paths. Also, the rate at which water is transmitted through a unit width of an aquifer under a unit hydraulic gradient. Transmissivity values are given in gallons per minute through a vertical section of an aquifer 1 foot wide and extending the full saturated height of an aquifer under a hydraulic gradient of one in the English Engineering System; in the Standard International System, transmissivity is given in cubic meters per day through a vertical section of an aquifer 1 meter wide and extending the full saturated height of an aquifer under hydraulic gradient of one. It is a function of properties of the liquid, the porous media, and the thickness of the porous media. Also see Transmissivity. COEFFICIENT OF VARIATION, or VARIABILITY—The Standard Deviation of a statistic expressed as a fraction of the mean or a percentage. COEFFICIENT OF VISCOSITY—The degree to which a fluid resists flow under an applied force, measured by the tangential friction force per unit area divided by the velocity gradient under conditions of streamline flow. COFFERDAM—A temporary watertight enclosure that is pumped dry to expose the bottom of a body of water so that construction, as of piers, a dam, and bridge footings, may be undertaken. Also, a watertight chamber attached to the side of a ship to facilitate repairs below the water line. A Diversion Cofferdam prevents all downstream flow by diverting the flow of a river into a pipe, channel, or tunnel. Also see Dam, Caisson and Camel. COHESION—A molecular attraction by which the particles of a body are united throughout the mass whether like of unlike. Compare to Adhesion. COI—Cone of Influence. COLD VAPOR—A method to test water for the presence of mercury. COLD-WATER—Lacking modern plumbing or heating facilities, as a cold-water residence.
COLDWATER FISH—A fish that requires relatively cool water for survival. While the optimum temperature varies by species, most are found in water where temperatures are 20C (68F) or less. COLIFORM (BACTERIA)—A group of organisms (Colon bacilli) usually found in the colons of all warm blooded animals and humans; non-pathogenic microorganisms used in testing water to indicate the presence of pathogenic bacteria. The presence of coliform bacteria in water is an indicator of possible pollution by fecal material. Generally reported as colonies per 100 milliliters (ml) of sample. COLIFORM INDEX—An index of the bacteriological quality of water, based on a count of the numbers of coliform bacteria. COLLECTION SITE—A stream, lake, reservoir, or other body of water fed by water drained from a watershed. COLLECTOR SEWERS—Pipes used to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility. COLLECTOR SYSTEM—Conveys water from several individual sources such as groundwater wells and drains and surface inlet drains for rainstorm and snowmelt runoff to a single point of diversion. The collector system is associated with projects that increase water supply and decrease flood damage. 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. COLLOIDAL SUSPENSION—Suspension in water of particles so finely divided that they will not settle under the action of gravity, but will diffuse, even in quiet water, under the random impulses of Brownian Movement. Particles typically range in size from about one micron (0.000001 millimeter) to about one millimicron; however, there is no distinct differentiation by particle size between true Suspension and colloidal suspension or between colloidal suspension and Solution. COLLOIDS—Quantities of extremely small particles, typically 0.0001 to 1 micron in size, and small enough to remain suspended in a fluid medium without settling to the bottom. Substances that, when apparently dissolved in water or other liquid, diffuse not at all or very slowly through a membrane and show other special properties, as lack of pronounced effect on the freezing point or vapor pressure of the solvent. Colloids represent intermediate substances between a true dissolved particle and a suspended solid, which will settle out of solution. COLLUVIAL MATERIAL—(Geology) Material consisting of Alluvium in part and also containing angular fragments of the original rocks. Typically found at the bottom or on the lower slopes of a hill. COLLUVIUM—A general term used to describe loose and incoherent deposits of rock moved downslope by gravitational force in the form of soil Creep, slides, and local wash. Also see Colluvial Material. COLON BACILLUS—(Microbiology) A rod-shaped bacterium, especially Escherichia coli (E. coli), a normal, generally nonpathogenic commensal found in all vertebrate intestinal tracts, but which can be virulent, causing diarrhea and other dysenteric symptoms. Its presence in water is an indicator of fecal contamination. COLONIZATION—(Biology) As applied to vegetation, the invasion of a disturbed area; annual plants are often colonizing species.
COLOR—(1) Measured in units that relate to a standard. A yellow-brown natural color is associated with lakes or rivers receiving wetland drainage. The average color value for Wisconsin lakes is 39 units, with the color of state lakes ranging from zero to 320 units. Color also affects light penetration and therefore the depth at which plants can grow. (2) One control of light transmission through water. High color values in many lakes result from the decomposition of vegetation, which gives the water a brown, tea-like color. Determined by a comparison with standardized colored-glass discs and reported in platinum-cobalt (Pt-Co) units. COLOR (OF LAKE WATERS)—An effect of light penetration, radiation absorption and reflection. Related to: transparency and depth of water;type of lake bottom and matter held in solution; suspension or floating. Blues and greens are commonly observed in clear water lakes with clean bottoms of sand, rock or marl. Often, the blue tints are in deeper water and greens in shallower sections. Greens are often due to large populations of blue green and green algae in suspension or on the lake bottom. Yellows may be due to certain species of algae and to diatoms in large populations, and in certain types of lakes yellows have been attributed to sulfur bacteria. Pale yellows, yellow brown and coffee color or "black," can be produced by large quantities of dissolved humic substances and by particulate organic matter in suspension. Reds may be a reflection of the pigment color of certain algae; and may be caused by the presence of certain micro-crustaceans and other zooplankton; the "blood lakes" of central Europe are attributed to the presence of the microorganism Euglena sanguinea. Lake waters may be variously colored by suspended particulate inorganic matter especially that which is clayey or colloidal in nature. Some glacial lakes may be milky because of "glacial flour" in suspension, and the shallow water of marl lakes is often milky. Some colors are reflections of yellow sands on shallow bottoms, or from the black of organic sediments; or the blue of the sky. Colors vary with the weather, the time of day and the season. The words white and black have been used to describe lake waters. White has been applied where the water is merely colorless, and sometimes where it is milky from grey or white particulate matter in suspension. Black may be due to: large amounts of humic matter in solution, such as that in water flowing from some kinds of bogs; reflection of black bottoms; the dull appearance of some waters when the sky is heavily overcast. Unusual colors may be produced by pollution from industrial wastes. COLORADO RIVER COMMISSION [Nevada]—An agency of the State of Nevada consisting of seven members, to include four members appointed by the Governor and three members from the Southern Nevada Water Authority Board of Directors. The Colorado River Commission has broad statutory authority to |
