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UNIT 18

Environmental Issues and Engineering

Part 1

What is the environment?
An environment represents the conditions and influences of a place in which an
organism lives. The large number of different types of environments, e.g., urban
environments, tropical rainforest environments, etc., makes it impossible to formulate
a single definition. The relationship between living organisms and their environment
forms part of the subject of ecology.

All over the world, wildlife is being threatened because habitats and woodlands are
being destroyed. Rainforests are being cut down so that people can use the land to
grow crops. Many animal and plant species have become extinct, and many more
are endangered, so they need legal protection if they are to survive. Some people
believe that global warming will produce rising sea levels and climate change and
that carbon dioxide emissions from the burning of fossil fuels are contributing to the
greenhouse effect. Acid rain, which contains acid from factory smoke, causes
damage to trees, rivers, and buildings. The world’s population is growing and puts
pressure on the limited resources of the Earth.

A. Choose the correct option.

1. Animals, birds, and plants that live in natural conditions are called:

a) habitats b) woodlands c) wildlife

2. The process in which heat is unable to escape from the atmosphere and

causes the temperature of the Earth to rise is:

a) global warming b) the greenhouse effect c) acid rain

3. A forest in a tropical region of the world where it rains a lot is:

a) a tropical rainforest

b) woodlands

c) forestry

4. The study of the environment and the way plants, animals, and humans live

together and affect each other is called:

a) environmentalism

b) green peace

c) ecology

5. The slow increase in the temperature of the Earth caused by the increased

amount of carbon dioxide in the atmosphere is:

a) global warming b) the greenhouse effect c) global effect

6. The type of place that an animal normally lives in or a plant normally grows in

is its: a) habitation b) habitat

c) habit

7. Many animal and plant species need protection by:

a) the courts and governments b) the Church

c) the media

8. Something that has died out and is no longer in existence is:

a) extinct

b) exit

c) exist

9. Something or someone that is threatened with extinction is:

a) damaged b) destroyed c) endangered

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B. Answer the following questions and discuss.

1. Which of the problems mentioned in the above text do you find the most

serious?

2. Does education play any role in people’s attitude toward the environment?
3. Can an individual do anything to protect the environment?
4. What do you personally do to protect the environment?

Let us give you a few suggestions:
•

••

• Switch the lights off when you leave the room and switch off electric

appliances whenever possible.

•

••

• Do not waste water; let it run only when necessary. Check if your water taps

are leaking.

•

••

• Walk to school or use public transport; it is more environmentally friendly

than going by car.

•

••

• Reuse plastic shopping bags, and when they are too damaged, put them in

the recycling bin.

•

••

• Use “green” products whenever it is possible.
•

••

• Put paper, glass, cans and plastic into special bins to be recycled.

What is environmental engineering?
Environmental engineering is the application of science and engineering principles to
improve the environment, provide healthful water, air and land for human habitation
and other organisms, and investigate the possibilities for remediation of polluted
places.

As long as people have recognized that their health and well-being are related to the
quality of their environment, they have applied thoughtful principles to improve its
quality. The Romans constructed aqueducts to prevent drought and create a clean
healthful water supply for the metropolis of Rome. Bavaria in the 15

th

century

created laws restricting the development and degradation of the alpine country that
contained the region’s water supply. Modern environmental engineering began in
London in the middle of the 19

th

century when it was realized that proper sewerage

could reduce the incidence of waterborne diseases such as cholera or typhoid fever.
The introduction of treatment of drinking water and sewage in industrialized countries
reduced waterborne diseases from leading causes of death to rarities.

These days engineers and scientists assess the impacts of proposed projects on
environmental conditions. They evaluate if there are likely to be any adverse impacts
on water quality, air quality, habitat quality, flora and fauna, noise impacts, visual
impacts, etc. If impacts are expected, they then develop mitigation measures to
prevent such impacts. Engineers and scientists also work to secure water supplies
for potable and agricultural use. Water is treated to achieve water quality objectives
for its end users. Most urban and many rural areas no longer discharge human
waste directly on the land through outhouses or septic tanks, but rather deposit such
waste into water and convey it from households by means of sewer systems.

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C.

Say if these sentences are true or false. Correct the false ones.

1. The health and well-being of people are not related to the quality of their

environment.

2. The Romans constructed aqueducts to prevent floods.
3. In the past people were interested in the quality of their environment.
4. Typhoid is a waterborne disease.
5. The impact of new projects on the environment is not taken into consideration.
6. In developed countries people discharge human waste directly on the land.
7. Human waste should be treated and detoxified before it is discharged into a

river or ocean system.

D. Match the words in column A to the gaps in column B.

A

B

1) potable

a) ___________ is a reduction of an unpleasant, harmful or
serious situation.

2) habitation

b) __________ is a long period of dry weather when there
is not enough water for plants and animals to live.

3) waste

c) _________ is an underground pipe or passage that
carries waste water and refuse.

4) pollution

d) ___________ is the study of the environment and the
way plants, animals, and humans live together and affect
each other.

5) aqueduct

e) __________ is unwanted materials or substances that
are left after you have used something

6) drought

f) __________ is the act of living in a place.

7) mitigation

g) __________ is a structure like a bridge, used to carry a
water supply across valley.

8) sewer

h) __________ water is suitable for drinking.

9) ecology

i) __________ is the process of making air, water, soil, etc.
dangerously dirty and not suitable for people to use.

E. Match the synonyms or words with similar meanings.

1) impact

a) supply

2) assess

b) release

3) clean

c) occupancy

4) provide

d) methods

5) habitation

e) carry

6) polluted

f) influence

7) measures

g) uncontaminated

8) treatment

h) consider

9) discharge

i) handling

10) convey

j) contaminated

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Part 2

Waste Management

Waste management is the process of managing waste materials that are produced
as a result of human activities. It involves the collection, transport, processing and/or
disposal of waste materials. Waste management practices are often very different
between urban and rural areas and between residential and industrial producers,
even in the same local region. There are various waste management concepts. One
of them is represented by the term ‘3Rs’, or ‘Reduce – Reuse – Recycle’, which
practically means to extract the maximum practical benefits from products and to
generate the minimum amount of waste.

There is a new practice of holding the producer of a product responsible to some
extent for the management of waste products associated with that product, e.g.,
motor vehicles, large appliances, like ovens and refrigerators, tyres, electronic
equipment, including computers, and mobile phones.

Domestic, industrial and commercial waste is collected and then removed. The
removal of waste is called waste disposal. Collection and disposal methods vary
widely between different countries and regions. In large countries with a low
population, solid waste is carried to landfills. Disposing of waste in a landfill is the
most traditional method of waste disposal, and it remains a common practice in most
countries. Disposed waste should be compacted and covered to prevent problems
with pests, rats and wind-blown litter. A modern and well-run landfill should include
methods to prevent leakage. In smaller countries with a high population density,
incineration is the most common method of disposing of waste. It is the process of
destroying waste by burning it, which might be harmful for the environment if pollution
control measures are not applied. A relatively recent idea in waste management has
been to treat the waste material as a resource to be exploited, and some developed
countries have developed methods by which resources may be extracted from waste.
The most environmentally friendly method of getting rid of waste is to recycle it,
which means to reuse the materials that would otherwise be considered waste. The
most common items recycled include glass and plastic bottles, paper in any form,
aluminium cans and, more recently, obsolete computers, kitchen appliances or other
electronic equipment.

A. Find words or expressions in the article which mean:

1. typical of the countryside (par. 1)
2. area in which most buildings are houses (par. 1)
3. the control and operation of a business or organization (par. 2)
4. made smaller or firmer by pressing it

(par. 3)

5. the process of seeping out, escaping (par. 3)
6. no longer used because replaced by something newer and more effective

(par. 3)

B. Choose the best answer to each question.

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1. What is waste management?

a) It is the process of generating a maximum amount of waste.
b) It is the process of managing waste materials by the collection, transport,

processing and disposal of waste material.

c) It is the transportation of waste to landfills.

2. What are the producers of a product responsible for in terms of waste

management?
a) They are responsible for recycling waste associated with their

production.

b) They are not responsible for anything.
c) They are responsible to some extent for the management of the waste

products associated with that product.

3. What was the traditional way of managing domestic, industrial and commercial

waste?
a) Domestic, industrial and commercial waste was collected and recycled,

respectively.

b) Domestic, industrial and commercial waste was collected and composted,

respectively.

c) Domestic, industrial and commercial waste was collected and sent to a

landfill, respectively.

4. What is the most common method of waste disposal in small and densely

populated countries?
a) Incineration.
b) Land fills.
c) Recycling.

5. Which method is the most traditional and cheapest way of waste disposal?

a) Composting.
b) Land fills.
c) Collecting.

6. Why should disposed waste in landfills be covered?

a) To prevent people stealing any items from them.
b) To prevent spreading a bad odour.
c) To prevent rats, pests and wind-blown litter.

7. Why is recycling considered an efficient method of waste disposal?

a) Because the waste materials may be treated as a resource to be exploited.
b) Because recycling is a very cheap method of waste disposal.
c) Because people cannot do anything else with waste.

C. Mark the odd word in the line.

rats

pests

mice

dogs

incineration

landfill

covering

composting

furniture

magazines

newspapers

paperboard

pollution

contamination

prevention

smog

waste

bin

rubbish

litter

plastic bottles

computers

mobile phones

refrigerators

disposal

removal

elimination

addition

generate

produce

destroy

make

incinerate

extinguish

burn

cremate

reduce

recycle

reuse

reprocess

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D. Read the text again and complete the sentences.

1. Waste management involves ___________, ___________, ___________ and

___________ of waste materials.

2. One concept of waste management is the concept of ‘3Rs’, which means

___________, ___________, ___________.

3. In compliance with a new practice, ____________ of a product are held

responsible to some extent for the ___________ of __________ __________.

4. Managing domestic, industrial and commercial waste has traditionally

consisted of ___________, followed by ___________.

5. _____________ means burying waste in a large hole in the ground.
6. A well-run ___________ can be a hygienic and relatively inexpensive method

of ___________ of waste materials.

7. Disposed waste should be ___________ and covered to prevent problems

with ________ and ___________ litter.

8. ____________ is the process of destroying waste by burning it.
9. The most environmentally friendly method of __________ ____ of waste is to

___________ it.

10. A relatively recent idea in waste management has been to treat the waste

material as a __________ to be exploited.

E. Decide which waste management practices are more preferable and why.

Waste Management

Practice

Pros

Cons

Open dumps

Covered landfills

Incineration

Composting

Recycling

93

UNIT 15

Fundamentals of Urban Drainage

A. Read the explanations of these new terms and try to find the correct term in

the Slovak language. Check in a dictionary.

sewage

a mixture of waste from the human body and used water that is carried
away from houses by sewers, e.g., Chlorine is used to treat sewage.

sewer

a pipe or passage under the ground that carries away waste material and
used water from houses and factories

sewerage

the system by which waste material and water are carried away in sewers
and then treated to stop it from being harmful

drainage

a system of pipes or passages in the ground for carrying away water or
waste liquids, e.g., drainage channels

to drain

to make water or liquid flow away from something, e.g., Deep ditches were
dug to drain the fields.

runoff (technical)

rain or other liquid that flows off the land into rivers and streams

sludge (technical)

the solid substance that is left when the liquid waste from houses, factories,
etc., (sewage) has been cleaned

flow

a smooth steady movement or supply of liquid

treatment

a process by which something is cleaned, protected, etc., e.g., the
treatment of waste oils and solvents

B. Fill in the proper word. Choose from the following.

sewage (2), sewers (2x), sludge, runoff, treatment (3x), drains, wastewater

1.

__________ transport _____________ from a building to _____________

facilities.

2.

Most __________ are arranged so that gravity moves the ___________.

3.

Storm _________ are large pipes that transport storm-water __________ from

streets to avoid their flooding.

4.

____________ is treated in a _____________ plant.

5.

Chemical _____________ removes bacteria and offensive smells from the

__________ and water.

C. Choose the most logical option.

1. Originally, cities had no sewers. Where did wastewater go?

a) It dried out.

94

b) Wastewater ran down the streets, which had stepping stones to keep

pedestrians out of muck.

c) People swept it away.

2. Where does untreated sewage go in developed countries?

a) It is released directly to surface water.
b) It is conveyed to a treatment plant.
c) It is kept in enormous septic tanks and later recycled.

3. Most large cities have
a) a single sewer for surface runoff, household and

commercial sewage.

b) separated and combined sewers.

c) open channel drainage.

D. Read the text.

A complete well-functioning urban drainage (sewerage) and treatment system is the
most effective solution to the sewage and urban runoff problem. Such systems allow
utilization of the most modern methods for household and commercial wastewater
disposal, including flushing toilets and in-sink garbage grinders. The need for
cesspools, septic tanks, and other on-site sewage disposal systems is therefore
eliminated.

A planning report of an urban drainage system has to contain drainage area
characteristics such as topography, drainage patterns, surface conditions, location of
streets and existing drainage systems to which the proposed system may be
connected. It also has flow rates and the quality of the receiving waters, along with
future developments, which include population trends, land use, the present and
projected quantity and quality of the sewage and storm-water runoff, etc., as well as
the environmental policy and standards information and the financial aspects of the
planned system.

E. Match the underlined words from the text with their synonyms or words

with similar meaning. Change their grammatical form where necessary

landscape –

strategy –

overflow –

removal –
eradicate –
tendency –
municipal –

F. Answer the following questions.

1. What is the urban sewerage system a substitution for?
2. What belongs to an on-site sewage disposal system?
3. What aspects are important in planning an urban sewerage system?
4. Why are these aspects important?
5. Why do population trends have to be considered in urban drainage system

planning?

95

The main types of sewer systems are:

a) separated sewers
b) combined sewers
c) open channel drainage.

a) Separated sewers consist of storm sewer networks that mainly carry surface
runoff from streets, roofs, parking lots, and other surfaces toward the nearest
receiving water body or a man-made channel, and sanitary sewers that carry
household and commercial sewage and industrial wastewater toward a treatment
plant.
b) Combined sewers are used for the collection and conveyance of both surface
runoff and sanitary sewage and industrial wastes in one conduit. Combined sewer
systems are common in older U.S. and European urban centers. Urban drainage by
separate systems is more expensive than a combined sewer system since it uses
two parallel networks of conduits.
c) Open channel drainage includes swales, roadside ditches, and drainage
channels. The channels should be lined either with a man-made lining (asphalt,
concrete, gabions, mats) or natural grasses and sod. Grassed, maintained
waterways are an excellent and cheap alternative to underground storm sewers,
especially in suburban zones. They enhance the infiltration and attenuation of
pollutants.

G. In the text about sewer systems find the words with the following meanings:

1. a long narrow passage for water or other liquids to flow along

_______________ (par. a)

2. relating to people’s health especially to the system of supplying water and

dealing with human waste _____________ (par. a)

3. the process of transporting something or someone from one place to another

_______________ (par. b)

4. a pipe or passage that water flows through to go from one place to another

________________ (par. b)

5. reduction of the strength, amount or size of something ______________

(par. c)

6. a long narrow hole dug along the side of a road or field, so that water can run

into it ______________ (par. c)

H. Read the part about sewer systems again and explain the difference

between them. Then read about the sewer types.

Sewer types.
Sewers can be divided into:
a) building sewers
b) lateral (branch) sewers,
c) main (trunk) sewers
d) interceptors and outfall (relief) sewers.

a) Building sewers connect a building’s plumbing to the nearest lateral (branch)

public sewer line. The minimum recommended size of building connections is

96

100 mm for single-family homes, and the minimum slope should be 2 %. The
building connection should be equipped with backwater gates if there is a danger
of sewer backup and basement flooding.

b) Lateral (branch) sewers are used to collect wastewater from building

connections and convey it to a main sewer. A lateral sewer has no other sewer
tributary except building connections. The minimum diameter of lateral (branch)
sewers should be 200 mm.

c) Main (trunk) sewers accept flow from several lateral (branch) sewers and convey

it to a treatment plant or to an intercepting sewer.

d) Interceptors are large sewers that were originally designed to accept dry weather

flow from a number of trunk sewers and carry the flow to a treatment facility. In
more recent systems large interceptors are used for storage of combined sewer
overflows (in-line storage).

Common sewer materials include concrete (plain or reinforced), vitrified clay, iron
and steel (cast iron, ductile iron, corrugated steel), and polyvinyl chloride (PVC).
Small and medium-sized sewers are assembled mostly from concrete or vitrified clay
pipes. In general, both materials are similarly economic and, when installed properly,
infiltration should be minimal. For larger flows, cast-in-place concrete sewers are
used when standard concrete pipes are not available. Practices differ for different
types of sewers.

I. Say if the sentence is true or false. Correct the false sentences.

1. Separated sewers consist of storm sewer networks and sanitary sewers.
2. Sanitary sewers mainly convey surface runoff.
3. Combined sewers are used for collection and conveyance of industrial wastes

and sanitary sewage in two conduits.

4. A conduit is a pipe.
5. Population trends are important for the planning of an urban drainage system.
6. Building sewers are connected directly to main sewers.
7. Main sewers convey wastewater to a treatment plant or an intercepting sewer.
8. A well-functioning urban drainage system eliminates the need for cesspools or

septic tanks.

Compound Nouns

A compound noun consists of two or more nouns joined together. Compound nouns
occur frequently in scientific and technical writing precisely because they give them
conciseness. The more technical and specialized the subject, the more frequent and
more complicated the compound nouns. The most complicated compound nouns
occur in newspaper headlines and technical advertisements. Compound nouns are
sometimes difficult to understand. However, they are not as difficult as they look if
you always follow this principle: begin at the end and then work backwards!
E.g., wastewater disposal, in-sink garbage grinders, on-site sewage disposal system
There are three things to notice about compound nouns:
1. Some compounds are joined by a hyphen and some are not. There are no rules

for the use of hyphens, e.g. wastewater, waste water, waste-water.

2. The first half of a compound is never plural, e.g., a student hostel, a 50-centimeter
ruler.

97

3. The relationship between the two nouns forming the compound can take many

different forms, e.g., an oilcan, oil exports, an oilfield, oil pollution, an oil heater,
an oil expert.

1. Find the compound nouns in the text and underline them.

2. See the word explanations in the pre-reading part of this unit and the

vocabulary at the end of this unit and try to explain the meanings of the
following compounds by using similar defining clauses.
E.g., A sewage treatment facility is a facility for processing sewage.

storm runoff

on-site sewage disposal system

channel drainage

backwater gate

surface water

sludge digestion

runoff problem

household wastewater plumbing

wastewater disposal

sewage treatment facility

3. Explain the difference in the meaning of these expressions:

channel drainage and drainage channel

surface water and water surface

treatment facility and facility treatment

99

UNIT 16

Wastewater Treatment

A. Read the article (Part I.) briefly and underline the key words in the text.

Explain their meaning.
wastewater, pollution, contamination, damage, sewage treatment plant, solid,
disposal, disease-producing organisms

B. Discuss.

1. Are natural water resources safe? Can you eat fish caught in the river

Danube?

2. Have you heard of a case of natural water (streams, lakes, ponds or oceans)

contamination? If so, where was it? Was there any damage to the water
fauna or flora?

3. Where can the leakage of chemicals be critical? What can be done to prevent

it?

4. Do you think treatment plants might help prevent such cases?
5. What are the conditions of wastewater treatment if you compare developed

countries and developing ones?

Read the text.

Part I.
All municipal sewage and wastewater must eventually find their way into water
courses or other bodies of water that constitute the natural drainage of a region. This
can cause damage, including contamination and pollution of water supplies,
swimming and bathing beaches; shellfish contamination, killing of fish, the creation of
conditions offensive to sight or smell, and impairment of the use of natural waters for
recreation, agriculture, commerce, or industry. The primary objective of sewage and
wastewater treatment is to prevent such damage to receiving waters.

However, only conveying the wastewater to the nearest treatment plant can solve
this problem. Treatment plants are an integral part of an entire sewerage system.
Thus, planning, development, and operation of sewage treatment plants depend
upon the character of the collecting system and upon the means for ultimate disposal
of the wastewaters. In choosing the treatment process to be employed and in
determining the degree of treatment, consideration must be given to the location of
the plant, the nature of its present and anticipated future surroundings, the character
and waste assimilative capacity of the available receiving water body, and the uses
to which these waters are to be put. The engineer who designs a treatment plant
should be familiar with the regional water development and wastewater disposal
plans. Civil and environmental engineers must master not only the technical details
but also the economic and social implications of their planning. Therefore, they have

100

to seek the most economical and objective solutions to all the problems that are
presented to them.

The pollution content of sewage consists of organic and inorganic compounds, which
exist partially as suspended solids (settled, suspended, or floating) that move with
the water and partially as dissolved solids. There are also small living organisms
(e.g. bacteria) that find nourishment in the sewage’s organic matter and may cause
uncontrolled decomposition of sewage, resulting in offensive odor problems and an
unsightly appearance. There is also the potential for the presence of disease-
producing organisms.

C. Match the following phrases from the article.

1. Municipal sewage and wastewater

must find

a) to the nearest plant

2. contamination and pollution

b) of the available receiving water

body

3. conveying the wastewater

c) the most economical and

objective solution

4. operation of sewage treatment

plants

d) their way into water courses.

5. the

character

and

waste

assimilative capacity

e) should

be

familiar

with

wastewater disposal plans

6. The engineer who designs a

treatment plant

f) of water supplies

7. engineers have to seek

g) may

cause

uncontrolled

decomposition of sewage

8. small living organisms

h) depend upon the character of

the collecting system

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D. Fill in the gaps with appropriate words


However, only _________ the wastewater to the nearest
treatment plant can solve this problem. Treatment plants
are an integral part of an entire ___________ system.
Thus, planning, development, and operation of sewage
___________ plants depend upon the character of the
collecting system and upon the means for ultimate
__________ of the wastewaters. In choosing the treatment
process to be employed and in determining the degree of
treatment, consideration must be given to the _________ of
the plant, the nature of its present and anticipated future
surroundings, the character and waste ___________
capacity of the available receiving water body, and the uses
to which these waters are to be put. The engineer who
designs a treatment plant should be familiar with the
regional water development and __________ disposal
plans. Civil and environmental engineers must master not
only the technical details but also the economic and social
__________of their planning. Therefore they have to seek
the most economical and __________ solution to all the
problems that are presented to them.

The pollution content of sewage consists of organic and
inorganic ___________, which exist partially as suspended
solids (settled, suspended, or floating) that move with the
water and partially as __________ solids. There are also
small living organisms (e.g. bacteria) that find
____________ in the sewage’s organic matter and may
cause uncontrolled ____________ of sewage, resulting in
__________ odor problems and an ___________
appearance. There is also the potential for the presence of
disease-producing organisms.

sewerage

treatment

location

assimilative

conveying

disposal

implications

objective

wastewater


compounds

nourishment

offensive

unsightly

dissolved

decomposition

Part II.
The removal and stabilization of sewage materials is accomplished in treatment work
that can be categorized into the following groups:

1. Mechanical processes:
a) Screening: Because of their size the particles will be trapped on screens or

bar racks. Sand filters work predominantly in the same fashion.

b) Flotation units: As a result of their buoyancy, pollutants will rise to the surface

where they can be skimmed off, for example, as in grease traps and skimming
tanks.

c) Sedimentation tanks and clarifiers: Particles sink to the bottom of the tanks

because of gravity.

2. Chemical processes: chemical additives enhance the ability of particles to

settle or kill microorganisms (chlorine).

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3. Biological processes: The life processes of nature are used in sewage

purification:

a) naturally in the soil or ponds and lagoons
b) artificially on trickling filters, activated sludge units, or septic tanks.

The efficiency of the treatment plant as well as the effects on the environment and on
the surrounding residential areas must be considered. Modern treatment plants are
often partially automated and equipped with a number of telemetric sensors and
measuring devices. The signals reflect the operating conditions of various units and
are transmitted to a centrally located control room.

E. What kind of process do the following words describe?

Screening is the process of...
Floating...
Skimming...
Sedimentation...
Purification is the act of...

F.

Fill in the gaps in the following paragraph with the correct word from the

following word couples.

1

power/treatment,

2

current/volume,

3

charge/pay,

4

money/charge,

5

bills/material,

6

sludge/water

7

sewage/stormwater, ,

8

fares/fees,

9

consumption/waste,

10

irrigation/drying

out

A

1

_________ plant measures the incoming

2

_________ from major pipes in

order to track and

3

________ customers. Generally the sewage

4

__________ is

actually paid as a surcharge on customers’ water

5

________. The difference

between incoming

6

_________ and outgoing

7

_________ is used to establish the

sewage rate

8

________ as a percentage of water use. The metering also gives

administrators a means to measure water

9

_________ and

10

_________ of lawns

and other diversions to the storm sewers.

G. Answer the following questions or follow the tasks.

1. What is the primary objective of sewage and wastewater treatment?
2. What can be damaged due to untreated wastewater getting into the bodies of

water?

3. What is an integral part of a sewerage system?
4. What do civil and environmental engineers need to consider in planning the

treatment process?

5. What substances can be found in sewage?
6. How are they treated?
7. What are the categories of sewage treatment work?
8. Describe the three types of mechanical processes.
9. Is implementing treatment plants in the sewerage system obligatory in our

country?

10. Why is it important to use a wastewater treatment plant as a part of the

sewerage system?

103

Technical texts contain a number of reductions that make them more
concise. Gerunds (e.g. swimming), forms of the past participle (e.g.
suspended), abstract nouns (e.g. contamination) and compound nouns
(e.g. treatment plant) are used for this purpose.

H. Find as many of them as possible in both parts of the text.

Gerunds

Past participles

Abstract nouns

Compound nouns