vodonosnye layers
Thanks to security vodonosnyh layers artesian water is characterised by a full transparency, dullness, absence of the weighed and organic substances, differs high cleanliness in the bacterial relation, stability of physical and chemical indicators. mezhplastovoj the significant amount of the mineral salts dissolved in it which chemical compound depends on structure of breeds in which it collects and moves is peculiar to water. The water chemical compound differs a constancy, and if it is broken, it testifies to sanitary trouble of a source. Pollution deep vodonosnyh horizons can occur through cracks in the terrestrial breeds, the thrown mines and wells, at a filtration of industrial sewage through a bottom and walls of incorrectly arranged equipment of a chink.
Superficial waters. An atmospheric precipitation, superficial and underground waters ; flowing down on natural biases of the earth to the lowered places, form opened (flowing and landlocked) reservoirs (a stream, the river, lake). Open reservoirs are unreliable in the sanitary relation water supply sources. So, physical, chemical and bacteriological properties of river water depend on a sanitary condition of the river, the settlements located on its coast and the industrial enterprises, and also the period of year. It is known, that in the winter river water becomes purer in the bacterial relation, and in the spring and in the autumn the sanitary condition of the river worsens at the expense of a plentiful drain of an atmospheric precipitation. Along with increase bacterial obsemenennosti from which the river was protected earlier by an ice cover, under the influence of thawed snow the quantity of mineral salts and oxidability of water decreases. In the summer in connection with a heavy use of river water considerable growth of microorganisms in this water, including pathogenic occurs the population.
Descent of industrial and fekalno-economic sewage, steamship landing stages, a fishing craft, mass bathing - all it influences structure of water and can create danger of bacterial pollution.
The Structure of river water depends as well on an environment. So, yellow colour of river water (chromaticity to 65 ° ’) and high oxidability (15-16 mg of Og/l) are caused by that some rivers (Kama, Dnepr) originate in marshland and take out therefrom guminovye substances. If the river originates from district with the clay soil, the clay suspension washed away by a current causes proof mutnost waters. It is peculiar to such rivers, as Syrda-. rja, Kuban.
Thus, an environment and densely populated territories influence physical and chemical structure of river water and the maintenance in it of microorganisms.
Lakes have the structure of water which is coming nearer to river, as in basic they are formed at the expense of water of the rivers running into them. Optimum sources of water supply are the big and deep lakes. In them almost completely there is a sedimentation of the weighed substances, and organic substances containing in silt promote course of biochemical processes. So, on depth of 10 m and more water differs high cleanliness in} the bacterial relation, and its temperature and a chemical compound fluctuate in insignificant limits. Therefore the device of water supply from such lakes is more favorable, than from the rivers.
However thus it is necessary to observe sanitary requirements to a choice of a place of a fence of water, an arrangement of a water intake taking into account that in lake household and industrial sewage which in the absence of the expressed current can influence on considerable distance can arrive.
Building of hydroelectric power stations, industry development, creation new and growth of old cities have served as the reason of accumulation of stocks of water and their concentration near to consumers. Artificial reservoirs or the water basins formed as a result of rising of water in the river by means of a dam have been for this purpose created. Now in our country is about I thousand
Water basins with volume of water more than 1 million in m 3 everyone. Water basins of many rivers (Volga, Kama, Dnepr, Yenisei, Angara) are a source of water supply for a number of settlements.
The Chemical compound of water of water basins depends on structure participating in its formation river, thawed, rain and subsoil waters. Characteristic line of these reservoirs is gradual increase of concentration of mineral salts in the water, connected with evaporation of water from a surface of water basins. The less depth of a water basin, the is more strongly expressed in it a water mineralization. Most mineralizovannaja water is in the bottom layers of a reservoir, and arriving in it less mineralizovannaja water, owing to smaller relative density, remains in the top layers.
The Following feature of water basins is the summer flowering of water connected with growth of seaweed and formation of hydrogen sulphide at the expense of their subsequent dying off. It leads also to reduction of the maintenance of the dissolved oxygen in water and  destruction of fish. Seaweed besides, getting on treatment facilities worsens their operation.
In water basins it is necessary to develop actions for elimination of the reasons of deterioration For the prevention of damage of water organolepticheskih properties, a chemical compound of water, its possible organic pollution. With that end in view it is necessary to clear a bowl of a water basin before its flooding from wood and kustarnikovoj vegetation to warn saturation of water by products of its disintegration. Define places and conditions of descent of sewage and after that - places of a fence of water for waterpipes of the occupied places.
Water supply in a number of the occupied places is made at the expense of channels on which river water is brought in shallow areas. Some channels build specially for water supply of the occupied places (Severski Donets - Donbass, Dnepr - Krivoi Rog). Use of these channels on other appointment and access to them are forbidden. With that end in view along channels it is laid special inspektorekaja a highway.
For water supply can be used and the ponds representing small artificial reservoirs, the waters of streams formed as a result of detention and keys. Such ponds have above populated line of settlement, and in their water modular territory there should not be pollution sources. Round a pond the strip of green plantings and a zone of sanitary protection is created.
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