Glossary of Terms - W
A B C D E F G H I J K L M N O P Q R S T U V W Z
water (H2O) - An odorless, colorless, tasteless liquid which exists as ice in solid form (phase) and steam in vapor form (phase). It freezes at 32° F (0° C) and boils at 212° F (100° C).
Water is a polar liquid with high dielectric constant which accounts for its solvent power; it is called the universal solvent.
It is a weak electrolyte; in pure water, only about two molecules in every 1,100,000,000 separate into H3O+ and OH- ions. Water is only slightly compressible.
It is the liquid that descends from the clouds as rain and forms lakes, streams, and seas (oceans). Water is a major constituent of all living matter.
Also referred to as H2O (dihydrogen oxide) and HOH (hydrogen hydroxide).
water closet - A flushable toilet.
water conditioning - The treatment or processing of water, by any means, to modify, enhance, or improve its quality or to meet a specific water quality need, desire, or set of standards. Also called water treatment.
water cycle - See hydrologic cycle.
water density (maximum) - The maximum density of water is reached at 39° F (4° C). It becomes less dense at both higher and lower temperatures.
water hammer - The shock wave or series of waves caused by the resistance of inertia to an abrupt change (acceleration or deceleration) of water flow through a water piping system. Water hammer may produce an instantaneous pressure many times greater than the normal pressure. For this reason, many building codes now require the installation of a "water hammer arrestor," a device to absorb these shock waves and prevent damage to appliances such as washing machines.
water logged tank - A tank (as in domestic water well pumping system) in which too much water has accumulated and has replaced some of the air in the tank’s air cushion (bladder) causing a disruption in the normal pressure pattern needed for pumping and uniform water flow.
A compound which, when introduced into water used for cleaning or washing, will counteract the effects of the hard water minerals (calcium and magnesium) and produce the effect of softened water. For example, detergent additives and polyphosphates.
A pressurized water treatment device in which hard water is passed through a bed of cation exchange media (either inorganic or synthetic organic) for the purpose of exchanging calcium and magnesium ions for sodium or potassium ions, thus producing a softened water which is more desirable for laundering, bathing, and dishwashing. This cation exchange process was originally called zeolite water softening or the Permutit Process. Most modern water softeners use a sulfonated bead form of styrene/divinylbenzene (DVB) cation resin.
water softener salt - Salt suitable for regenerating residential and commercial cation exchange water softeners. Most commonly used for this purpose is sodium chloride (NaCl) in crystal or pelletized form. Rock grade salt should be 96-99 percent NaCl; evaporated salt should be 99+ percent NaCl. Potassium chloride (KCl) may also be used for the regeneration cycle in the cation exchange process, thus minimizing the amount of sodium added to both the softened water and the spent regenerant water going to the drain.
water softening - The reduction/removal of calcium and magnesium ions, which are the principal cause of hardness in water. The cation exchange resin method is most commonly used for residential and commercial water treatment.
water table - The level of groundwater. The upper surface of the zone of saturation of groundwater above an impermeable layer of soil or rock (through which water cannot move) as in an unconfined aquifer. This level can be very near the surface of the ground or far below it.
water treatment - See water conditioning.
water treatment device - Any point-of-use or point-of-entry instrument or contrivance sold or offered for rental or lease for residential or commercial use, and designed to be added to the plumbing system, or used without being connected to the plumbing of a water supply intended for human consumption in order to improve the water supply by any means, including, but not limited to, filtration, distillation, adsorption, ion exchange, reverse osmosis, or other treatment.
Water Quality Association (WQA) - The Water Quality Association (WQA) is a not-for-profit international trade association representing the household, commercial, light-industrial, and small system water quality improvement industry. (www.wqa.org)
WQA - Water Quality Association. (www.wqa.org)
well - A bored, drilled, or driven shaft, or a dug hole, whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids below ground.