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Tailwater
recovery system:
System modification to achieve
greater efficiency in agricultural irrigation by collecting runoff for reuse
in irrigation.
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Tail-water
runoff: Unused
irrigation water or rain water that is collected at the base or end of an irrigated
system or field in a ditch or impoundment. This water may be reused again for
irrigation purposes, be left to evaporate, percolate into the ground, receive
treatment, and (or) be discharged to surface-water bodies.
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Total dissolved
solids (TDS):
The sum or all inorganic
and organic particulate material. TDS is an indicator test used for wastewater
analysis and is also a measure of the mineral content of bottled water and groundwater.
There is a relationship between TDS and conductivity. People monitoring water
quality can measure electrical conductivity quickly in the field and estimate
TDS without doing any lab tests at all. See specific conductance.
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Temperature: The degree of
hotness or coldness.
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Tensiometer: Type of soil
moisture probe used to monitor soil moisture conditions to help determine when
water should by applied.
-
Tertiary
treatment: Removal
from wastewater of traces or organic chemicals and dissolved solids that remain
after primary treatment and secondary treatment.
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TH: Total Hardness.
The sum of calcium and magnesium hardness, expressed as a calcium carbonate
equivalent.
-
Thalweg: The line of maximum
depth in a stream. The thalweg is the part that has the maximum velocity and
causes cutbanks and channel migration.
-
Thermal
gradient: Temperature
difference between two areas.
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Thermal
pollution: The
impairment of water quality through temperature increase; usually occurs as
a result of industrial cooling water discharges.
-
Thermal
pollution: An
increase in air or water temperature that disturbs the climate or ecology of
an area.
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Thermocline: Fairly thin zone
in a lake that separates an upper warmer zone (epilimnion) from a lower colder
zone (hypolimnion).
-
Thermoelectric
power: Electrical
power generated by using fossil fuel (coal, oil, natural gas or biomass), geothermal,
or nuclear energy.
-
Thermoelectric
power water use:
Water used in the process
of the generation of thermoelectric power. The water may be obtained from a
public supply or may be self supplied. See also public supply and self-supplied
water.
-
THM: Trihalomethanes.
Toxic chemical substances that consist of a methane molecule and one of the
halogen elements fluorine, bromine, chlorine and iodine attached to three positions
of the molecule. They usually have carcinogenic properties.
-
Threshold
level: Level
established as the average rate of water use.
-
Threshold
pollutant: Substance
that is harmful to a particular organism only above a certain concentration,
or threshold level.
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Tiered pricing: Increasing block-rate
pricing.
-
Time-of-day
pricing: Pricing
that charges users relatively higher prices during utilities' peak use periods.
-
Titration: An analytical
technique to determine how much of a substance is present in a water sample
by adding another substance and measuring how much of that substance must be
added to produce a reaction.
-
Toilet displacement
device: Object
placed in a toilet tank to reduce the amount of water used per flush; for example,
weighted plastic jugs filled with water or toilet dams that hold back a reservoir
of water when the toilet is flushing.
-
Total solids: All the solids
in wastewater or sewage water, including suspended solids and filterable solids.
-
Toxic: Harmful to living
organisms.
-
Toxic water
pollutants: Compounds
that are not naturally found in water at the given concentrations and that cause
death, disease, or birth defects in organisms that ingest or absorb them.
-
Toxicity
reduction evaluation (TRE):
A study conducted to determine
the source(s) of toxicity in a discharge effluent so that these sources can
be controlled sufficiently to allow a discharger to comply with their permit
limits.
-
Toxicity
test: The means
to determine the toxicity of a chemical or an effluent using living organisms.
A toxicity test measures the degree of response of an exposed test organism
to a specified chemical or effluent.
-
Tragedy
of the Commons:
The idea that no one takes
responsibility for things that everybody owns.
-
Transmission
lines: Pipelines
that transport raw water from its source to a water treatment plant.
-
Transmissivity: Refers to the
rate at which limestone allows the transmission of water. Limestone can be highly
porous, but not very transmissive if the pores are not connected to each other.
Technically speaking, it is the rate at which water is transmitted through a
unit width of aquifer under unit hydraulic gradient. Transmissivity is directly
proportional to aquifer thickness, thus it is high where the edwards is thick
and low where it is thin, given the same hydraulic conductivity.
-
Transpiration: Process by which
water that is absorbed by plants, usually through the roots, is evaporated into
the atmosphere from the plant surface. See also evaporation and evapo-transpiration.
-
Treated
(wastewater) effluent:
Water that has received
primary, secondary, or advanced treatment and is released from a wastewater
facility after treatment.
-
Treatment
plant: A structure
built to treat wastewater before discharging it into the environment.
-
Tributary: A stream that
contributes its water to another stream or body of water.
-
Trickling
filter: A wastewater
treatment unit that contains medium material with bacteria. The stream of wastewater
is trickled over the medium and the bacteria break down the organic wastes.
Bacteria are collected on the filter medium.
-
Troposphere: The layer of
atmosphere closest to the Earth, extending seven to ten miles above the surface,
containing most of the clouds and moisture.
-
TS: Total Solids.
The weight of all present solids per unit volume of water. It is usually determined
by evaporation. The total weight concerns both dissolved and suspended organic
and inorganic matter.
-
Tsunami: A Japanese term
that has been adopted to describe a large seismically generated sea wave capable
of considerable destruction in certain coastal areas, especially where sub-marine
earthquakes occur.
-
Tube settler: Device using
bundles of tubes to let solids in water settle to the bottom for removal by
sludge.
-
Turbid: Thick or opaque
with matter in suspension. Rivers and lakes may become turbid after a rainfall.
-
Turbidity: Cloudiness caused
by the presence of suspended solids in water; an indicator of water quality.
-
Turbulent
flow: A flow
that contains may rapid fluctuations.
