Youth Activities: Water Resources
This glossary was developed to accompany the Youth Activities: Water
Aeration:  The process of bubbling air through water or
wastewater to remove impurities.
Aquifer:  Areas underground where groundwater exists in
sufficient quantities to supply wells or springs.
Coagulation:  A clumping of particles in water and wastewater
to settle out impurities; it is often induced by chemicals such as lime,
alum, and iron salts.
Condensation:  The process by which a vapor becomes a liquid.
Contamination (Water):  The adding of any substance to water
which makes it unfit for use.
Disinfection:  A process whereby most microorganisms in
or on a substance are killed; there is A high probability that pathogenic
(disease causing) bacteria are killed in the process but depending on
the process, destruction of viruses is not as certain.
Distillation:  The separation of different substances in
a solution by boiling off those of low boiling point first.  For
example, water can be distilled and the steam condensed back into a
liquid that is almost pure water.  The impurities (minerals) remain
in the concentrated residue.
Diatomaceous Earth:  An earthy deposit formed mainly of
diatoms (one-celled marine life forms) that are pulverized and resemble
Erosion:  The wearing away of the land surface by wind,
water, ice, or other geologic agents.  Erosion occurs naturally
from weather or runoff but is often intensified by human land use practices.
Evaporation:  The process by which water becomes a vapor
usually through the application of heat energy.
Filtration:  A mechanical process which involves moving
water through a material, usually sand, designed to catch and remove
Floc:  The large particles formed in water and wastewater
treatment processes when small particles begin to coalesce.
Floculation:  The formation of floc in the water and wastewater
Groundwater:  Water found under the ground, in aquifers
and between soil particles.
Groundwater Recharge:  Water that moves below the root zone
as "deep percolation" and eventually joins the groundwater.
Hard Water:  Water containing excessive amounts of calcium
and magnesium ions which prevents soap from lathering and produces scale
Hydrologic Cycle (Water Cycle):  The cycle of water movement
from the atmosphere to the earth and back to the atmosphere through
condensation, precipitation, evaporation, and transpiration.
Infiltration:  The gradual downward flow of water from the
surface into the soil.
Irrigation:  The controlled application of water for agricultural
purposes through human-made systems to supply water requirements for
crops not satisfied by rainfall.
Leaching:  The process by which soluble materials in the
soil, such as nutrients, pesticide chemicals, or contaminants, are washed
into a lower layer of soil or are dissolved and carried away by water.
Nonpoint Source (NPS) Pollution:  Forms of pollution caused
by sediment, organic and inorganic chemicals, and biological, radiological,
and other toxic substances originating from land use activities, which
are carried to lakes and streams by surface runoff.  Nonpoint source
pollution occurs when the rate of materials entering these waterbodies
exceeds natural levels.
Percolation:  The movement of water through the subsurface
soil layers, usually continuing downward to groundwater.
Pollutant:  Anything which alters the physical, chemical,
or biological properties of water making it harmful or undesirable for
Precipitation:  Water received on Earth directly from clouds
as rain, hail, sleet, or snow.
Runoff:  Precipitation that flows overland to surface waters,
such as streams, rivers, and lakes.
Sedimentation:  The removal, transport, and deposition of
detached soil particles by flowing water or wind.  Also, the process
of solid particles settling out of water and wastewater treatment processes.
Soft Water:  Any water that is not "hard," i.e., does not
contain a significant amount of dissolved minerals such as salts containing
calcium or magnesium.
Soil Profile:  A vertical section of the Earth's highly
weathered upper surface often showing several distinct layers or horizons.
Stream:  A general term for a body of flowing water.
In hydrology, the term is generally applied to the water flowing in
a natural channel as distinct from a canal.  More generally, it
is applied to the water flowing in any channel, natural, or artificial.
Surface Water:  All water on the surface of the Earth including
lakes, ponds, rivers, oceans, streams, puddles, and runoff.
Transpiration:  The process by which water vapor escapes
from the living plant, principally the leaves, and enters the atmosphere.
Wastewater Treatment Plant:  A facility that receives wastewater
(and sometimes runoff) from domestic and/or industrial sources, and
by a combination of physical, chemical, and biological processes reduces
(treats) the wastewater to less harmful byproducts; also known by the
acronyms WWTP, STP (sewage treatment plant), and POTW (publicly owned
Water Table:  The upper surface of the zone of saturation;
the upper surface of the groundwater.
Watershed:  The land area from which surface water and runoff
drains into a stream, channel, lake, reservoir, or other body of water;
also called a drainage basin.