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Wafer fabrication
rinse sink: Apparatus
used during manufacturing to rinse debris and contamination from the circular
configuration of semiconductor chips.
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Waste disposal
system: A system
for the disposing of wastes, either by surface or underground methods; includes
sewer systems, treatment works, and disposal wells.
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Wastewater: Water containing
waste including greywater, blackwater or water contaminated by waste contact,
including process-generated and contaminated rainfall runoff.
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Wastewater
infrastructure:
The plan or network for
the collection, treatment, and disposal of sewage in a community.
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Wastewater
treatment: The
processing of wastewater for the removal or reduction of contained solids or
other undesirable constituents.
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Wastewater
treatment plant:
A facility containing a
series of tanks, screens, filters, and other processes by which pollutants are
removed from water.
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Wastewater-treatment
return flow:
Water returned to the hydrologic system by wastewater-treatment facilities.
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Water: The liquid that
descends from the clouds as rain; forms streams, lakes, and seas, and is a major
constituent of all living matter. It is an odorless, tasteless, colorless, very
slightly compressible liquid.
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Water audit: Program involving
sending trained water auditors to participating family homes, free of charge,
to identify water conservation opportunities such as repairing leaks and installing
lowflow plumbing and to recommend changes in water use practices to reduce home
water use.
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Water conservation: Activities designed
to reduce the demand for water, improve efficiency in use, and reduce losses
and waste of water.
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Water contamination: Impairment of
water quality to a degree that reduces the usability of the water for ordinary
purposes or creates a hazard to public health through poisoning or the spread
of diseases.
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Water cycle: Natural pathway
water follows as it changes between liquid, solid, and gaseous states; biogeochemical
cycle that moves and recycles water in various forms through the ecosphere.
Also called the hydrologic cycle.
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Water management: The study, planning,
monitoring, and application of quantitative and qualitative control and development
techniques for long-term, multiple use of the diverse forms of water resources.
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Water monitoring: The process of
constant control of a body of water by means of sampling and analyses.
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Water pollution: Industrial and
institutional wastes and other harmful or objectionable material in sufficient
quantities to result in a measurable degradation of the water quality.
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Water quality: A term used to
describe the chemical, physical, and biological characteristics of water with
respect to its suitability for a particular use.
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Water quality
criteria: Scientifically
derived ambient limits developed and updated by EPA, under section 304(a)(1)
of the Clean Water Act, for specific pollutants of concern. Criteria are recommended
concentrations, levels, or narrative statements that should not be exceeded
in a waterbody in order to protect aquatic life or human health.
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Water quality
guidelines: Specific
levels of water quality that, if reached, are expected to render a body of water
suitable for its designated use. The criteria are based on specific levels of
pollutants that would make the water harmful if used for drinking, swimming,
farming, fish production, or industrial processes.
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Water quality
standards: Laws
or regulations, promulgated under Section 303 of the Clean Water Act, that consist
of the designated use or uses of a waterbody or a segment of a waterbody and
the water quality criteria that are necessary to protect the use or uses of
that particular waterbody. Water quality standards also contain an antidegradation
statement. Every State is required to develop water quality criteria standards
applicable to the various waterbodies within the State and revise them every
3 years.
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Water quality-based
toxics control:
An integrated strategy used
in NPDES permitting to assess and control the discharge of toxic pollutants
to surface waters. There are two approaches: the whole-effluent approach
involves the use of toxicity tests to measure discharge toxicity; the chemical
specific approach involves the use of water quality criteria or State standards
to limit specific toxic pollutants directly.
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Water recycling: Reuse of water
for the same application for which it was originally used.
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Water reuse: Using wastewater
or reclaimed water from one application for another application. The deliberate
use of reclaimed water or wastewater must be in compliance with applicable rules
for a beneficial purpose (landscape irrigation, agricultural irrigation, aesthetic
uses, ground water recharge, industrial uses, and fire protection).
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Water solubility: The maximum possible
concentration of a chemical compound dissolved in water.
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Water storage
pond: An impound
for liquid wastes designed to accomplish some degree of biochemical treatment.
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Water supply
system: The collection,
treatment, storage, and distribution of potable water from source to consumer.
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Water surcharge: Imposition of
a higher rate on excessive water use.
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Water system: A river and all
its branches.
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Water table: Level below the
earth's surface at which the ground becomes saturated with water. The surface
of an unconfined aquifer which fluctuates due to seasonal precipitation.
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Water table
aquifer: An aquifer
confined only by atmospheric pressure (water levels will not rise in the well
above the confining bed).
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Water transfer: Artificial conveyance
of water from one area to another across a political or hydrological boundary.
This is referred to as an import or export of water from one basin or county
to another.
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Water use: 1) In a restrictive
sense, the term refers to water that is actually used for a specific purpose
such as domestic use, irrigation, or industrial processing. 2) More broadly,
water use pertains to human’s interaction with and influence on the hydrologic
cycle, and includes elements such as water withdrawals, deliveries, consumptive
use, wastewater releases, reclaimed wastewater, return flow and instream use.
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Water use
efficiency: Employing
water-saving practices to reduce costs and to slow the depletion of the water
supply to ensure future water availability.
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Water well: Any artificial
excavation constructed for the purpose of exploring for or producing ground
water.
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Water year: The 12-month
period, usually October 1 through September 30. The water year is designated
by the calendar year in which it ends and which includes 9 of the 12 months.
Thus, the year ending September 30, 1998 is called the1998 Water Year.
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Waterfall: A sudden, nearly
vertical drop in a stream, as it flows over rock.
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Waterlogging: Saturation of
soil with irrigation water so the water table rises close to the surface.
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Watermaster: An employee of
a water department who distributes available water supply at the request of
water right holders and collects hydrographic data.
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Water-resources
region: Designated
natural drainage basin or hydrologic area that contains either the drainage
area of a major river or the combined drainage areas of two or more rivers;
of 21 regions, 18 are in the conterminous United States, and one each are in
Alaska, Hawaii, and the Caribbean. (See map on inside of front cover.).
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Water-resources
subregion: The
21 designated water-resources regions of the United States are subdivided into
222 subregions. Each subregion includes that area drained by a river system,
a reach of a river and its tributaries in that reach, a closed basin(s), or
a group of streams forming a coastal drainage system.
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Watershed: Land area from
which water drains toward a common watercourse in a natural basin.
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Watthour
(Wh): An electrical
energy unit of measure equal to one watt of power supplied to, or taken from,
an electrical circuit steadily for one hour.
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Weather: Day to day variation
in atmospheric conditions. Compare climate.
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Weir: A spill over
device used to measure or control water flows.
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Well: A pit, hole,
or shaft sunk into the earth to tap an underground source of water.
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Well capping: Capping of abandoned
artesian wells whose rusted casings spill water in a constant flow into drainage
ditches.
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Wet deposition: See acid rain.
-
Wetland: Area that is
regularly wet or flooded and has a water table that stands at or above the land
surface for at least part of the year, such as a bog, pond, fen, estuary, or
marsh.
-
Wettability: The relative
degree to which a fluid will spread into solid surface in the presence of other
immiscible fluids.
-
Whole-effluent
toxicity: The
aggregate toxic effect of an effluent measured directly by a toxicity test.
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W-Index: An index of water
efficiency used as a device for evaluating residential water savings and as
a management tool to motivate water-saving practices. The index provides a calculated
numerical value for each dwelling unit, derived from the number and kind of
water-saving features present, including indoor and outdoor water savers and
water harvesting or recycling systems.
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Winter/summer
ratio: Comparison
of metered water use during the winter period to consumption during the corresponding
summer period. A higher rate or surcharge is imposed for water consumption above
the average winter use.
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Withdrawal: Water removed
from the ground or diverted from a surface-water source. The amount of water
withdrawn may not equal the amount of water used due to water transfers or the
recirculation or recycling of the same water. For example, a power plant may
use the same water multiple times but withdraw a significantly different amount.
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Withdrawal
use: The act
of removing water from surface water or groundwater sources in order to use
it.
