Artesian water

Artesian water - groundwater between the two waterproof layers under pressure (Fig). Education natural pressure occurs: 1) when impermeable layer forms a hollow, in which there are two water flow coming from different areas of nutrition and forming artesian basin; 2) when the well at the intake water is below the plot of ground water recharge. Drilling wells to obtain water, put in artesian aquifers, called artesian wells (see water supply Sources).Artesian water
The shallow groundwater (scheme): 1 - impermeable layers; 2 - water-bearing horizon; 3 - water-bearing horizon of inter-layer non-artesian water; 4 - an aquifer interstratal pressure (artesian) waters; 5 and 6 wells, eating cross non-artesian water; 7 - a well-fed interstratal pressure (artesian water.
In some cases, cross water, under pressure, to come to the surface of the soil or in the bed of the river, forming springs or keys.
The chemical composition of groundwater is determined by the chemical composition of the soil and underlying rock, with whom they were in contact. Natural artesian water, profilirovaniya through significant thickness of soil, covered by a waterproof layers and isolated from ground and surface dirt, usually have high quality indicators (e-coli more than 300) and can be used for economic purposes and drinking without treatment, however, because of the possibility of contamination of artesian water (for example, violation of sanitary rules of the construction of wells) a question about the procedure and the possibilities of their use for drinking should be solved on the basis of data of sanitary-epidemiological survey wells and chemical-bacteriological examination of water (see Water).