Definition - What does Aquifer mean?
An aquifer is a layer or zone below the surface of the earth which is capable of yielding a significant volume of water.
Aquifers may occur at various depths. Those closer to the surface are more likely to be used for water supply and irrigation, as well as more likely to be topped off by local rainfall.
Aquifers are a major source of water for industrial processing units as well as residential use, therefore quality and purity have a major impact on the corrosion of materials.
Corrosionpedia explains Aquifer
An aquifer is an underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand or silt) from which groundwater can be extracted using a water well. There are two types of aquifers:
- Unconfined aquifers are those into which water seeps in from the ground surface directly above the aquifer.
- Confined aquifers are those in which an impermeable dirt/rock layer exists that prevents water from seeping into the aquifer from the ground surface located directly above.
An aquifer can be contaminated by many things. Deliberate disposal of waste at point sources such as landfills, septic tanks, injection wells and storm drain wells can have an impact on the quality of ground water in an aquifer. Contaminants can reach the water table by any natural or man-made route along which water can flow from the surface to the aquifer.
Chemical substances found in water can corrode metal well casings. Sulfate-reducing bacteria can also cause corrosion. Mineral incrustation is a common problem in some shallow-water-table-type aquifers where there is an abundance of dissolved minerals including calcium, magnesium and iron, as well as iron bacteria. When water is pumped from the well, changes in pressure and temperature occur. This creates ideal conditions for minerals to precipitate or settle out, causing scale formation on piping, fixtures and industrial equipment. Saline aquifer contains highly concentrated aqueous salts such as sodium chloride and calcium chloride, which have high potential for corrosion.
Aquifer water needs to purified, demineralized and conditioned for industrial uses to avoid corrosion.