-
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.
