Environmental Engineering Reference
In-Depth Information
Ionic bond:
The attractive forces between oppositely charged ions, such as
the forces between the sodium and chloride ions in a sodium chlo-
ride crystal.
Irrigation:
Controlled application of water to arable land to supply require-
ments of crops not satisfied by rainfall.
Irrigation return flow:
The part of irrigation applied to the surface that is
not consumed by evapotranspiration or taken up by plants and that
migrates to an aquifer or surface water body.
Irrigation withdrawals:
Withdrawals of water for application on land to
assist in the growing of crops and pastures or to maintain recre-
ational lands.
K
Kill:
Dutch term for stream or creek.
L
Lacustrine:
Pertaining to, produced by, or formed in a lake.
Leachate:
A liquid that has percolated through soil containing soluble sub-
stances and that contains certain amounts of these substances in
solution.
Leaching:
The removal of materials in solution from soil or rock; also
refers to movement of pesticides or nutrients from land surfaces to
groundwater.
Limnetic:
The deepwater zone (greater than 2 meters deep).
Littoral:
The shallow-water zone (less than 2 meters deep).
Load:
Material moved or carried by streams, reported as weight of material
transported during a specified time period, such as tons per year.
M
Main stem:
The principal trunk of a river or a stream.
Marsh:
A water-saturated, poorly drained area, intermittently or perma-
nently water covered, having aquatic and grasslike vegetation.
Maturity (stream):
The stage in the development of a stream at which it has
reached its maximum efficiency, when velocity is just sufficient to
carry the sediment delivered to it by tributaries; characterized by
a broad, open, flat-floored valley having a moderate gradient and
gentle slope.
Maximum contaminant level (MCL):
The maximum allowable concentra-
tion of a contaminant in drinking water, as established by state and/
or federal regulations. Primary MCLs are health related and manda-
tory. Secondary MCLs are related to the aesthetics of the water and
are highly recommended but not required.
