Systems of water supply of the occupied places

There are two systems of water supply of the occupied places centralised (waterpipe) and decentralised, or local. At the centralised system of water supply water delivery to the consumer occurs on pipes, at local by means of various container: buckets, bochek, tankers. Advantages of the centralised water supply are conclusive, as this system allows by means of a number of constructions and a network of pipelines water from a waterworks to deliver direct to a consumption place. At the decentralised system of water supply reception of water and its transportation are fraught with danger of pollution.

At a choice of a source for settlement water supply prospects of growth of the last and accomplishment development are considered. The question on quantity of water already in itself can make solving impact on a water source choice.

On the basis of the hygienic characteristic of sources of water supply set forth above it is possible to draw a conclusion, that it is necessary to give preference to underground waters as they in bolshej degrees are protected by layers of breeds blocking them from pollution from a surface. The big advantage are also the small maintenance of microorganisms and good physical and chemical properties of underground waters that is provided natural by thanks to a filtration through layers of earth. It releases from necessity to resort to difficult system of clearing.

However not always underground waters can provide enough of water for a food of large settlement. It is necessary to consider also technical and economic feasibility of use of this or that source. F.F.Erisman in this occasion wrote: ' Hygiene should not prevent excessive insistence concerning quality of water to choose that water which carrying out manages more cheaply and which can be had in a considerable quantity; it is necessary to have only confidence, that water can be recognised by good-quality and anyway harmless '.

At a choice of a water source bodies of the state sanitary inspection are guided by GOST 17 ' Rules of a choice and an estimation of quality of sources of the centralised economic-drinking water supply '. Water research is thus spent under the scheme of the full sanitary analysis which includes the indicators listed in appendices 3 and 4 STATE THAT.

Except conformity of water to requirements STATE THAT it is necessary to establish also, whether its quality will worsen subsequently. With that end in view spend sanitary-and-hygienic inspection of a water source: reveal existing or possible sources of pollution, their sanitary and epidemic danger; find out the reasons of pollution of a water source, pollution size; define volume and the program of laboratory researches; establish borders of zones of sanitary protection. It is carried out by visual, polling and anamnesticheskogo studying of a water source and territory surrounding it. The sources of pollution revealed thus are put on topographic maps, situational plans of district with distance instructions between sources of pollution and a water source. Thus state a hygienic estimation to a pollution source on capacity of receipt of polluting substances (chemical or bacterial) and their sanitary and epidemic danger to a human body. The industrial sewage containing cancerogenic, radioactive and especially toxic substances concern the most dangerous sources of pollution. Sources of possible chemical and bacterial pollution also concern them: absorbing and soaking up wells, fields of an irrigation, a filtration, sewage disposal and zapahivanija, navozohranilishcha, stores of household and industrial sewage, cattle-breeding complexes.

Studying of level of infectious disease of the population Is of interest for the characteristic of a water source. Revealing bakterionositelej or the persons who are ill with infectious diseases at whom water (a cholera, a belly typhus, a paratyphus, a salmonellosis, a dysentery, amebiaz, ljamb-lioz, leptospirozy, a water fever, an infectious jaundice - illness Vasileva-Vejlja), brutsellez, tuljaremija can be the transfer factor, the Siberian ulcer, a tuberculosis, gelmintozy (askaridoz, three-hotsefalez, difillobotriz, opistorhoz), an infectious hepatitis (Botkin's illness), enterovirusnye diseases (a poliomyelitis, Koksaki), and also some adenovirusnye diseases is with that end in view spent.

In the presence of infectious diseases find out character of flash (number of diseases, territorial distribution) and results of epidemiological inspection of separate cases. Establish possibility of occurrence of the diseases as which reason such circumstances as repair of the water elevating equipment, penetration into a water source of thawed snow or an atmospheric precipitation after strong rains could serve; presence epizootii among animals in the given district etc.

The Revealed sources of pollution liquidate and establish zones of sanitary protection, i.e. Territory round a source of water supply and head water constructions with the special mode warning adverse changes in quality and quantity of water. At use for water supply of superficial waters allocate two belts of sanitary protection. Borders of the first belt, or a zone of a strict mode, should be established depending on local sanitarnotopograficheskih and hydrological conditions, but in all cases than 200 m from a water fence should settle down upstream on distance not less; downwards on a current-not less of 100 m from a water fence, on adjoining to a water fence I protect not less than 100 m from a line ureza waters at its highest level. In territory of the first belt all kinds of building, residing of people, release of drains, bathing, a watering place and vypas cattle, linen washing, fishing, application of pesticides, organic and some kinds of mineral fertilizers are forbidden.

Borders of the second belt of sanitary protection of the river or the channel, being a water supply source, establish taking into account possible pollution of an open reservoir and its ability to self-cleaning.

At the expense of self-cleaning processes concentration of arriving pollution, especially pathogenic microflora decreases. It is established, that process of dying off of pathogenic microorganisms in the rivers basically comes to the end during five, and in the conditions of a hot climate of three days. On the basis of it the top border of the second belt should be removed from a water fence so that water run has provided the specified period of time. In this connection at use of the large rivers of border of a zone extend on tens kilometres (20-30 km), and at use of the small rivers in the second belt include all river basin. On territori the second belt all kinds of building are resolved by bodies of sanitary-and-epidemiologic service with which terms of designing and object building are co-ordinated; the industrial enterprises, settlements and residential buildings should be arranged well; The economic-household and industrial sewage which are let out in open reservoirs, zones entering into the second belt, should have the raised degree of clearing. It is forbidden to pollute reservoirs and territory dump of a sewage, dust, manure, industrial wastes, pesticides etc.

At use of underground water sources of border of the first belt of sanitary protection should be established depending on degree of security maintained vodonosnogo horizon from pollution from a surface and hydrological conditions on distance from a water fence: for reliably protected horizons - not less than 30 m; for not protected, not enough the protected horizons and infi-ltratsionnyh water fences not less than 50 m. At an establishment of distance of border of the second belt to a water fence place are necessary to start with term of dying off of the microorganisms which are in underground waters, 200 days making less. At well protected from pollution vodonosnom horizon as have shown special researches, dying off time is reduced till 100 days. In this connection the size of the second belt fluctuates from 50 to 1000 m and more.

The Centralized water supply.

For the waterpipe device use the rivers, and then water basins and lakes more often. The waterpipe consists of head constructions (water intaking and treatment facilities, pump stations, the tank of pure water) and a water supply system.

Waterpipe Building begins with a choice of a place for a water fence. This place should provide enough of water irrespective of changes in a mode of a reservoir and to be free from dangerous pollution in the sanitary relation. The place of a fence of water gets out above on a watercourse from the settlement which is in this case by a source of pollution of water. Thus arriving pollution from territory of settlement will be carried away by a watercourse downwards and will not get to water intaking constructions.

The Second condition of a correct choice of a place of a fence of water is depth of the river: in a place of a fence depth should be not less than 2,5 m. It it is necessary for the prevention of deterioration of water at the expense of settling down in on -

verhnostnom a sheet of water of seaweed and benthonic vysokomineralizovannogo a layer rising at vzmuchivanii of oozy ground adjournment. Average diameter of a water intaking pipe is equal 0,5 m.

At a choice of a place of a fence of water from superficial water sources careful sanitary inspection of the territory surrounding a water source, and laboratory research of water is spent. Especially it is important at use for the centralised water supply of water from lakes as in the absence of a current pollution arriving in lakes can collect on its separate sites.