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annular space - open space between the casing and the side of a well |
spring - discharge area where groundwater moves from a shallow aquifer to the surface or surface waters: wetlands, ponds, lakes, streams and rivers can be wholly, or in part, spring-fed |
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aquifer - a waterbearing formation that is capable of transmitting water in sufficient quantities to serve as a source of water supply |
static water level - the level in a well attained by water at equilibrium in a well when no water is being taken from the well |
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aquitard - a geological formation that prevents the significant flow of water, e.g., clay layers or tight deposits of shale |
unsaturated - pores containing air or a mixture of air and water |
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baseflow - when groundwater flows to surface water |
permeability - the property of porous rock, sediment, or soil for transmitting a fluid: it is a measure of the relative ease of fluid flow under an energy gradient |
| bedding plane - in sedimentary or stratified rocks, the division planes that separate the individual layers, beds or strata | pitless adapter - device designed to replace the need for well pits and pumphouses — usually a metallic (brass) fitting that is attached to the casing below the frost line to connect the in-well water line to the buried water line leading to point of use |
| bentonite - a colloidal clay, largely made up of the mineral sodium montmorillonite, a hydrated aluminum silicate; bentonite commonly has the ability to absorb water and to swell accordingly | plume - a trail of dissolved contaminants in groundwater issuing from a contaminant source and spreading out as the trail travels in the direction of groundwater flow |
| capillary zone - area above the water table where groundwater is drawn upward and held in tension in the pore spaces | pore - small openings filled with air or water |
| continuous chlorination - involves the continuous addition of low levels of chlorine to a water supply | porosity - the amount of pore space in a formation |
| denitrification - the loss of nitrogen in soils by either biological or chemical mechanisms: this is a gaseous loss that is not related to loss by physical processes such as leaching | pumping water level - the water level in a well being pumped |
| discharge - when the water reappears above the ground surface | recharge - replacement of moving aquifer water with water infiltrating from the surface and percolating through unsaturated formations to the water table |
| evaporation - part of the water cycle where water (liquid) from the earth's surface is transformed to vapor and is added to the atmosphere | recharge area - area of land beneath which there is a measurable downward driving force below the water table: rolling or steep land-forms with coarse-textured deposits (e.g., sand plains, end moraines) are particularly important recharge areas because of their high vertical flow rates |
| evapotranspiration - the transformation of water (liquid) from both the earth's surface (evaporation) and from the surfaces of plants (transpiration) to the atmosphere | saturated - pores filled with water |
| flowing well - a well that has a static water level above the surface of the adjacent ground, causing the well to flow | shock chlorination - involves adding a large amount of chlorine to the water in the well and pumping it through the system: the chlorinated water is left in the system long enough to ensure complete disinfection |
| formation - bedrock (e.g., granite) or overburden deposits (e.g., sands and gravels) with pores containing water and air | solution channel - cavities formed in soluble rocks (such as limestone) by the dissolving action of moving water |
| fracture - breaks in rocks or soil due to folding or faulting | water cycle - continuous movement of water from the atmosphere to the earth's surface (precipitation), through (infiltration, percolation) formations to aquifers (recharge), back to the earth's surface (discharge, capillary rise, plant uptake) and to the atmosphere (evaporation, transpiration, evapotranspiration) |
| hole stabilizer - may be a steel casing, a concrete tile, or an open hole in solid bedrock | water table - depth at which all the pores are saturated |
| infiltration - movement of water from the earth's surface into formations | well - a hole made in the ground to locate or to obtain groundwater from an aquifer, and includes a spring around or in which works are made or equipment is installed for collation of water and that is or is likely to be used as a source of water for human consumption |
| inlet - allows groundwater to enter the well, and may be a slotted well screen in overburden aquifers or an open hole in bedrock | well casing - pipe, tubing or other material installed in a well to support its sides |
| jetting - propulsion of water under high pressure into sandy aquifers to create a hole for a well point | well screen - slotted or perforated cylinder that is attached to the bottom of the solid casing of a drilled well to keep formation particles out and let water in |
| Karst topography - water moving through fractures in limestone has dissolved the rock, enlarging fractures and creating caverns | overburden - the loose soil, clay, silt, sand, gravel or other unconsolidated material overlying the bedrock, whether transported or formed in place |
| peak water demand - highest rate of water use each day: well capacities or storage facilities must be able to meet this demand | specific capacity - result of dividing the pumping rate by the drawdown |