Water and Air Pollution Problems

Water and air pollution are the two main factors that destroy the environment in big cities. Paris has no industry, so the Seine is not polluted by industrial effluents but by sewer waters. However, this problem is being solved by building pollution control stations in a Paris suburb. The sewage is channeled into them and cleansed before it goes into the Seine. When visiting these installations, one can often see how pure water the processed water is – the engineers who work there drink it quite cheerfully.

Water is purified by mechanical and biological methods. The purified water is treated with chlorine and released into the rivers, whence it enters the water supply systems where it undergoes further and finer treatment.

Air is mainly polluted by heating systems and cars. When you look at a modern city from a hill top you get the impression of vapour (smog) lingering over the city especially when there are no winds which can air the city. However, when there is no wind they have smog. As regards heating, gas is used rather than coal for last years. The poisoned air is the most modern quarters of the city.

District heating is an effective method. Several heat-and-power plants generate steam, which is piped underground all round the city.

As for cars you know, of course, how heavy traffic is in big cities. The slower the traffic, the more exhaust fumes are. This problem will be solved in the near future.

The acuteness of the problem depends on how well the country is developed and on the number of the cars. Many of these problems are international in nature.

Water and Water Supply

Centralized water supply dates back to 2500 BC. Ancient Egypt had complex engineering structures for the purpose. Yet to this day the percentage of the population enjoying centralized water supply on the African continent and in Asia, too, is very low.

In our country, at the time of the Revolution of 1917, only one third of the towns had running water laid on, and, then, as a rule, only in the central part of the town. In the pre-war period of industrial development running water reached millions of flats all over the country. Water supply of the systems are practically all in the western and central parts of European Russia, were destroyed during the war and had to be built anew.

Fresh water shortage was first mentioned soon after the end of the Second World War. The first to feel the stint was Europe. The problem came to many as a complete surprise, something in the nature of an unexpected “catastrophe”. This catastrophe, however, should have been foreseen, for it follows logically from the development of human life on our planet and of Man’s industrial activity.

In the absence of centralized water supply, a man can do with about 25 litres of water a day for his various personal needs. But in the modern city water consumption per person is much higher. An average of 300 to 500 litres of water is spent daily on household and sanitary needs per one inhabitant of a modern city. You can see this vastly exceeds the necessary minimum of 25 litres. Why the discrepancy (difference)? Not because people leave their taps open. Because water is so abundant nobody thinks twice about taking a shower, or a bath, using the washing machine, washing the car, etc. The volume of water consumption is indicative not only of the efficiency of the water supply but also of the population’s living standards.

One need in water is growing. Simultaneously, the globe’s population is growing. In the past century the consumption of water by the world’s largest cities, such as Paris, London, Berlin and Moscow, has grown 80 to 100 times. During the famous heat wave of 1972 Moscow “drank” almost 5,000,000 cubic metres of water a day. This staggering figure seems to confirm the immediacy of the water dearth problem. In actual fact, however, the problem consists not so much in where to get pure water but in how to deliver it to where people need it.

 

Water Resources of the USA

The USA is one of the first countries whose developing economy has met with a shortage of pure fresh water. Such conflicting situations have been caused by the exceptionally rapid growth of water consumption and by the constancy of the size of river runoff. The water crisis began to show at the beginning of the 60s. It was then when the gigantic projects were born to transport fresh water from Canada and Alaska to the main territory of the USA. At the end of 60s it became evident that the problem could not be solved by purifying utilized water.

By spending large sums of money on developing gigantic desalination plants it became clear that by channeling the runoff from the neighbouring territories and from the ocean an increase in the volume of polluted water would be brought about, which even at present overfills the rivers and lakes of the country.

It is the runoff which can be used without a full regulation of rivers by hydrotechnical installations. It is possible by recycling the same volume of water, which claims great requirements to the quality of their purification.

The main increase in water consumption takes place in that sphere of national economy, where water is necessary principally for cooling purposes – in industry, especially in heat-power engineering.

How can water losses be replenished? It is necessary to note the evergrowing consumption of ground water. The removal of considerably greater volumes of ground water that are taken at present will not diminish their total storage for a long time. Water supply at the expense of ground water is also convenient to satisfy the every day necessities of the population.

Other reserves that can be used are the water of the ocean. A wide substitution of fresh water for salt water for cooling purposes is assumed, mainly in heat-power engineering.

Over one quarter of the whole consumption of water will become possible due to the use of seawater. As concerning the abovementioned projects according to which fresh water is to be transported from Canada and Alaska and the entailed possibility to use the great reserves of hydropower of the western part of the continent, they have been cancelled.