A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Wastewater
Water that has been used in homes, industries, and businesses that is not suitable for reuse as a drinking source unless it is treated.

Wastewater Treatment Return Flow
Water returned to the environment by wastewater treatment facilities.

Water Balance
See hydrologic budget.

Water Cycle
The circulation of water movement from the oceans to the atmosphere and to the Earth and return to the atmosphere through various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transportation.
See also hydrologic cycle.

Water Quality
A term used to describe the chemical, physical, and biological characteristics of water with respect to its suitability for a particular purpose.

Water Table
The water table is the upper surface of the saturated zone of an unconfined aquifer. The water table may be located at or near the land surface, or at some depth below the land surface. The depth of the water table may fluctuate seasonally throughout the year. Wetlands, springs, and seepages may occur where the water table intersects the land surface.

Water Well
An engineered device created to access subsurface water. Wells may be bored, or drilled (horizintally or vertically) or constructed as a vertical or horizontal shaft.
See also, Monitoring well, Observation well, Recharge Well, Dual Purpose Well, Test well, Well Rehabilitation, Well point.

Watershed
The topographic area drained by a river. Watershed boundaries can be defined for the contributing area to any portion of a river system. Watershed areas can be defined for most wetlands and include the total land area from which hydrologic input may be derived. In very flat areas, wetland watersheds are difficult to define.

Well
A hole in the ground made to gain access to an aquifer to obtain water for economic use. Wells may be dug (mostly old wells less than 50 feet deep) or drilled. Drilled water wells in solid rock are typically up to 300 feet deep. Wells in alluvial and glacial sediments are typically about 100 feet deep.

Well Development
The application of techniques after and during the drilling process that bring the well to its maximum yield capacity and achieve maximum well efficiency.

Well Point
A screened cylinder (usually steel and less than 4 inches in diameter) that is driven into the ground and which can serve to access ground water.

Well Rehabilitation
The process of using mechanical or chemical techniques to restore declining well yield caused by biological and or chemical encrustation of well casing and/or the gravel pack or rock formations immediately adjacent to the well bore.

Well Screen
A steel or plastic device that admits water to a well from the surrounding geologic formations but which prevents or reduces the likelihood of sediment entering the well. Design and selection of well screens is based of geologic and hydraulic criteria.

Well Sealing
Unused wells may need to be sealed in order to protect aquifers from surface contaminants, or to prevent comingling of waters from different aquifers in the same well, or from aquifers interconnected by different wells.
See also abandoned wells.

Well Tests
See pumping tests.

Wetfall
The deposition of pollutants on the land surface washed out of the atmospheric by precipitation. Atmospheric pollutants may also reach the ground in particulate form independent of rainfall.

Wetland
An area that is inundated or saturated by surface or ground water, supports a prevalence of vegetation adapted for life in saturated soil conditions, and is characterized by saturated, anaerobic soils. The term "wetland" includes bogs, marshes, swamps, wet meadows and other similar areas.

Withdrawal
Water removed from a ground or surface water source for use.