Well
Well is a broad English term for an excavation or drilled opening used to access groundwater. It may describe hand-dug, driven, bored or drilled construction, so record the method and completion.
Borehole
Borehole often emphasizes a drilled hole and is widely used outside North America. Some boreholes are monitoring or investigation holes rather than production water wells.
Tube well
Tube well commonly describes a relatively narrow well formed with pipe or casing, often screened in unconsolidated deposits. Regional usage and construction standards differ.
Static water level
The nonpumping water level referenced to a stated datum and measured after an appropriate recovery period. Record date and recent pumping.
Pumping water level and drawdown
Pumping water level is measured while the well is discharging at a stated rate. Drawdown is the difference between static and pumping level.
Yield and specific capacity
Yield is a discharge rate under stated test conditions. Specific capacity is yield per unit drawdown and can vary with pumping rate and time.
Casing, screen and open interval
These construction details determine where groundwater enters and how the opening is stabilized. A pump setting must respect the completed well and water-bearing interval.
A useful record
Record coordinates, datum, depth, casing and screen, pump setting, test rate and duration, levels over time, recovery, water quality and the local professional’s terminology.
Worked example
A record reading only “45 m borehole, 20 L/min” is incomplete. Add static level 12 m, pumping level 26 m after a stated test, pump setting 35 m, screen interval, test duration and date.
Sources
- U.S. Geological Survey — Water Resources Glossary
- U.S. Geological Survey — Basic Ground-Water Hydrology