Unit 1.2 Work of the Sanitary Engineer



Read the text and answer the following questions:

1) What is the significance of sanitary engineering in the growth of cities?

2) What made the task of sanitary engineering more complex?

3) What are the responsibilities of sanitary engineer?

The development of sanitary engineering has paralleled and contributed to the growth of cities. Without an adequate supply of safe water, the great city could not exist, and life in it would be both unpleasant and dangerous unless human and other wastes were promptly removed. The concentration of population in rela­tively small areas has made the task of the sanitary engineer more complex. Groundwater supplies are frequently inadequate to the huge demand and surface waters, polluted by the cities, towns, and villages on watersheds, must be treated more and more elaborately as the population density increases. Industry also demands more and better water from all available sources. The rivers receive ever-increasing amounts of sewage and industrial wastes, thus requiring more attention to sewage treatment, stream pollution, and the complicated phenomena of self-purification.

The public looks to the sanitary engineer for assistance in such matters as the control of malaria by mosquito control, the eradication of other dangerous insects, rodent control, collection and disposal of municipal refuse, industrial hygiene, and sanitation of housing and swimming pools. The activities just given, which are likely to be controlled by local or state health departments, are sometimes known as public health or environmental engineering, terms which, while descriptive, are not accepted by all engineers. The terms, however, are indicative of the important place the engineer holds in the field of public health and in the prevention of diseases.

1. Read the text again and give the summary of it using the following phrases:

• The text is devoted to…

• It is recognized that…

• The text puts forward the idea that…

 

Unit 1.3 The Sanitary Survey

Read the text and word the main idea of it.

A survey of all surroundings and conditions that may affect the quality of a water supply is highly important. For state certification of a supply a favorable survey report is required, in addition to a satisfactory bacteriological test.

Carriers are persons who harbor disease germs and excrete them in body discharges but show no signs of disease. A considerable proportion of all persons having typhoid fever become temporary or permanent carriers. They can be discovered by a laboratory test. No one having had typhoid should be allowed to prepare food for the public unless tested and shown not to be a carrier. Surveys are that they will find conditions that are potential sources of contamination and waterborne epidemics, that when bacteriological testing of the water indicates pollution, a survey may find the danger, and that the survey is a necessity for proper interpretation of bacteriological tests. Difficulties frequently arise in connection with single water samples from small well supplies that show presence of coliforms. A sanitary survey may indicate that they are probably of nonfecal origin and that such drastic action as condemnation of the supply is not justified. Hasty action in condemnation is especially likely to cause adverse criticism if the water has been consumed regularly without causing disease. Sanitary surveys require judgment and technical knowledge. Operational procedures and techniques for correcting defects are discussed in the following articles.

Read the text again and give the title to it.

 

Part II

Water

Unit 2.1 Water Supply

Discuss in pairs:

1) What were responsibilities of the earlier waterworks engineers?

2) Why did the treatment methods develop?

Read the text and see if your ideas are right.

Throughout recorded history large cities have been concerned with their water supply. Even ancient cities found that local sources of supply—shallow wells, springs, and brooks—were inadequate to meet the very modest sanitary demands of the day, and the inhabitants were constrained to build aqueducts which could bring water from distant sources. Such supply systems could not compare with modern types, for only a few of the wealthier people had private taps in their homes or gardens, and most citizens carried water in vessels to their homes from fountains or public outlets. Medieval cities were smaller than the ancient cities, and public water supplies were practically nonexistent. The existing aqueducts of ancient Athens, Rome, and the Roman provincial cities fell into disuse, and their purposes were even forgotten.

The waterworks engineer of ancient times labored under the severe handicap of having no type of pipe that could withstand even moderate pressures. He used pipe of clay, lead, and bored wood in small sizes, but even with these, as with masonry aqueducts and tunnels, he followed the hydraulic grade line and rarely placed conduits under pressure.

In the seventeenth century the first experiments were made with cast-iron pipe but it was not until the middle of the eighteenth century that these pipes were cheap enough for wide use. The durability of cast iron and its freedom from breaks and leakages soon made its use almost universal, although steel and other mater­ials were also used. This advance, together with improved pumping methods, made it economically possible for all but the smallest villages to obtain water supplies and to deliver the water into the homes of the citizens.

Although some cities were able to collect safe water from uninhabited regions and thereby reduce waterborne disease to a low level, many others found that their supplies were dangerously polluted and that the danger was increasing as population increased upon watersheds. Accordingly treatment methods were developed that, when properly applied, reduced the hazard.

Coagulants have been used in water treatment since at least 2000 B.C., as has filtration, however their use in municipal treatment in the United States was not common until about 1900. The application of various treatment techniques in the early part of the twentieth century resulted in the marked decrease in waterborne disease .

Philadelphia's water supply came, without treatment of any kind, from in­creasingly polluted rivers until 1906, when slow sand filters were completed. An immediate reduction in typhoid fever followed over a period of 7 years. A ten­dency to increase, possibly caused by further increases in the pollution of the untreated water, was checked by disinfection of the filtered water with chlorine. A still greater decrease was accomplished after 1920 by careful control over infected persons who had become carriers.

1. Notes to the text:

to meet sanitary demands – отвечать санитарным требованиям

to withstand moderate pressure – выдерживать умеренное давление

clay – глина

lead – свинец

bored wood – полое дерево

masonry – каменная кладка

coagulant – коагулянт

hydraulic grade line – линия гидравлического уклона

durability – прочность

leakage – утечка, просачивание

2. Match  the words in two columns and make the collocations:

1)  to meet                a) tap

2)  distant                 b) pipe

3)  private                 c) disuse

4)  public                  d) sanitary demands

5)  to fall into      e) sources

6)  cast-iron             f) outlet

3. Match the following English expressions to their Russian ones:

1) shallow wells a) методы очистки
2) springs and brooks b) места общего пользования
3) public outlets c) мелкие колодцы
4) dangerously polluted d) ручьи
5) treatment methods e) опасно зараженные

4. Read the text again and answer the questions:

1) Were local sources of water supply in ancient cities satisfactory?

2) Who could afford to have a private tap in ancient time?

3) Why were public water supplies practically nonexistent at Earlier time?

4) What were the difficulties of ancient waterworks engineer?

5) What building materials were used in the construction of water pipe?

6) What material made the water pipe use universal?

7) What advances made it economically possible for all to obtain water supplies?

5. Read the following statements and say whether they are true or false (T/F). If they are false correct them. Use the following phrases:

• That’s right…

• No objections…

• I don’t think it’s right…

• That’s wrong…

• According to the text…

1) In ancient cities local sources of supply met sanitary demands of the day.

2) The purpose of existing aqueducts of ancient Athens, Rome and the Roman provincial cities were forgotten.

3) The water works engineer of ancient times didn’t follow the hydraulic grade line.

4) In the 18th century the first experiments were made with cast-iron pipe.

5) The durability of cast iron made its use almost universal.

6) Coagulants have been used in water treatment at least 2000 b.c. 

6. Look through the text and find in the text English equivalents for the following words and word combinations:

1) городская очистка

2) методы очистки

3) болезнь, переносимая водой

4) загрязненные реки

5) уменьшить опасность

6) подавать воду в дома

7) полое дерево

8) акведуки из каменной кладки

9) помещать трубы под давлением

10) широкое использование

7. Discuss in pairs:

1) Ancient sources of water supply.

2) The range of the ancient water work engineer’s job.

3) Water Treatment Techniques.

 

Unit 2.2

Discuss in pairs:

1) What is it necessary to do in the design of waterworks project?

2) What are the periods of such design?


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