water conditioning - Virtually any form of water treatment designed to improve the aesthetic quality of water by the neutralization, inhibition or removal of undesirable substances. (Not health related.)

water cycle - See hydrologic cycle.

water hammer - A shock wave or series of waves produced by the abrupt acceleration or deceleration of water flow, due to inertia. Water hammer may produce instantaneous pressures many times the normal pressure.

water softening - The removal of calcium and magnesium, the ions which are the principle cause of hardness, from water.

water table - The level of the top of the zone of saturation, in which free water exists in the pores and crevices of rocks and other earth strata.

weak base load faction x - Is referred to as the "Theoretical Mineral Acidity (TMA). It is the sum of the chloride, sulfate, and nitrate.