ENVIRONMENTAL SCIENCE ENGINEERING
UNIT-II
1. Give one example for sustainable development.
i) water conservation
ii) rain water harvesting
2. What is Rio de Janeiro conference agreement?
The Rio declaration outlines the rights and responsibilities of nations as they pursue human development and well being, recognizing the development and environment and needs of present and future generations.

3. Define sustainable development
It is defined as ‘the development to meet the needs of the present without compromising the ability of future generations to meet their own needs’. Sustainable Development must balance the needs of society, the economy and the environment.
4. Define sustainability.
Sustainability can be defined as the ability of a society or ecosystem to continue functioning into the indefinite future without being forced into decline through complete loss of its strength or overloading of key resources on which that system depends.

5. What are the characteristics of a sustainable development?
i) All the material processes will be designed to be of cyclic nature.
ii) There will not be any waste material or pollution of air, water, land and
environment.
iii) The output from one system will be used as inputs to other systems.

6. Mention the few types of pollution.
The five types of pollution are
1. Air pollution
2. Water pollution
3. Land or soil pollution
4. Radio active pollution
5. Noise pollution
7. What are the impacts of man made pollution?

i) Industrial development
ii) Rapid growth of Automobiles
iii) Uncontrolled population growth
iv) Deforestation



8. Give examples on water borne diseases.

Water Borne Diseases Responsible Organism
Typhoid, paratyphoid, Diarrhoea, Cholera, Bacillary dysentery Bacteria
Amoebiasis, Giardiasis Protozoa
ViralHepatitis (Jaundice), Poliomyelitis Virus
Round worm, hookworm, threadworm Helminths


9. What are the major issues of sustainable development?
i) Deforestation and desertification
ii) Urbanization
iii) Industrialization
10.Define air pollution.
Air pollution may be defined as any atmospheric condition in which certain substances are present in such concentrations that they can produce undesirable effects on man and his environment.

11.Define water pollution.
It can be defined as “ the presence of some foreign substances or impurities in water in such quantity as to constitute a health hazard by lowering the water quality and making it unfit for use.”
12.Mention a few natural sources of pollution.

i) Forest fires produce more smoke and trace gases into the atmosphere.
ii) Explosive Volcanic eruptions can inject more SO2, smoke, particulate matter and trace gases.
iii) Dust storms are the main cause for wind blow dust in the air.
iv) Natural contaminants present in the air like bacteria, spores, cysts and pollens are more dangerous when inhaled.
13.Correlate Global warming with reference to CO2 concentration in air.
Global warming is defined as the increase in temperature of the earth which causes more changes in climate. CO2 plays the vital role to change in the intensity of the earth’s green house effect by about 55%.

14.What is the goal of environmental protection?
The ultimate goal of environmental acts and policies are to minimize the environmental impacts and to achieve a pollution free atmosphere or environment.

15.What are the various quality objectives of air?
 Clean air
 No acid rain
 Non toxic environment
 Total freedom from radiation

16.Mention any two environmental impacts of developmental project in your discipline.
i)pollution
ii)destroying the natural resources

17.Mention the environmental impact of high sodium content in soil.
i) Reduction of soil fertility
ii) Hazardous for human beings.

18.What are the causes for air pollution?
i) Industries
ii) Automobiles
iii) forest fires
iv) Radioactive materials

19.How will you rectify water pollution?
i) Sewage treatment
ii) Waste stabilization pond or oxidation pond
iii) Recycling

20.What is acid rain?
The presence of excess acid in the rainwater is called acid rain.acid rain is caused by air pollution. air pollutants causing acid rain are SO2 and nitrogen oxide

21.Define Green house effect.
It may be defined as “the progressive warming up of the earth’s surface due to blanketing effect of man made CO2 in the atmosphere.

22.What are the gases responsible for green house effect?
a. Watervapour(H2O)
b. Carbon dioxide(CO2)
c. Methane(CH4)
d. Nitrous oxide(N2O)
e. Ozone(O3)

23.How is ozone layer depleted?
i)one CFC molecule can destroy thousands of molecules of ozone
ii) halons are used in fire extinguishers. they do 10 times greater damage to the ozone compared to the CFCs.

24.Name the toxic metals which cause water pollution?
Mercury,copper,lead,zinc,cyanides,arsenic etc.


25.What are the toxic metals which cause air pollution?
i) Lead particulates (from automobile exhausts)
ii) Cadmium particulates (through cigarette smoking)
iii) Nickel particulates (in tobacco smoke)





Part-B (12 Marks)

1. Explain the various physical properties of soil owing to the impacts on land

PHYSICAL CHARACTERISTICS:
The physical characteristic of soil includes permeability, porosity, density and temperature.
1. Soil density:
i. The soil density varies greatly depending upon the degree of weathering.
ii. The average density of soil is 2.65gm/m
2. Porosity
i. In a given volume of soil, the spaces present between the soils particles is called as pore spaces. The percentage of soil volume occupied by pore spaces is called as porosity of the soil.
ii. It increases with increase in the percentage of organic matter in the soil.
iii. The two types of pore spaces are:
a. Micro pore spaces and
b. Macro pore spaces.
iv. Micro pore spaces are also called as Capillary pore spaces. They can hold more water.
v. The micro pore spaces restrict the free movement of water and air to a considerable extent.
vi. The macro pore spaces have little water holding capacity and they allow free movement of moisture and air in the soil under normal conditions.
3. Permeability:
i. The movement of water through the pore spaces is called as permeability of soil.
ii. It always depends upon the size of the pore.
iii. Loose soils have higher value of permeability and the compact soils have lesser permeability.
4. Temperature:
i. Soil temperature is also important in affecting the distribution and growth of micro organisms, animals and plants which is affected by the following different factors:
a) Color.
b) Texture.
c) Water content.
d) Climate and
e) Vegetation covers over the soil.
ii.The soil temperature influences root growth, the ability of roots to absorb nutrients, and the movement of organisms.
iii.Sandy soils absorb more heat and radiate it out quickly than clay or loam soils, while soils absorb lesser heat than black so
2. Briefly explain how natural calamities disturb the environment.
Natural calamities:
i. floods
ii. drought
iii. earthquake
iv. cyclone

i. Floods:
When the water from heavy rainfall,melting ice or snow or a combination of these exceeds the carrying capacity of the receiving river system,then it will lead to flood.
Causes of flood:
i.natural causes:

a. the natural factors which causes river floods are prolonged high intensity monsoonal rainfall.
b. In the snow fed rivers of north india,excessive snow -melt Could swell up the streams causing them to flood.
c. Blocking of free flow of the rivers because of enormous debris provided by land slides creates over flow of river water.

ii. Anthropogenic causes:

 Large scale deforestation in the upper catchments of major rivers. it leads to excessive flow of water to the plants causing floods and inundation.
 Accumulation of wastes, refuse and garbage, filling of urban drains, gradual encroachment of human settlements near the channels, building construction of roads are the significant factors causing river floods.
Effects of floods:
• Deforestation.
• Damage to vegetation.
• River change their course during floods.
Flood control measures:
a) flood plain zoning
b) flood-proofing measures
c) flood risk maps

ii. Drought:

It is defined as an extended period a season, a year, several years of deficient rainfall relative to the statistical multiyear average for the region.

Causes:
Lack of rain fall
Inadequate water supply to plants, animals and human beings.
There is a serious scarcity of water to drink, use in farms, or provide for urban and industrial use.
Impacts of drought:
i. Effect on agriculture,economy and health
 Crop losses
 Loss of income
 Causes of disaster
ii. Effect on forestry and water resources

 Wild fires
 Tree and plant diseases
 Less productivity of forest land
 Land degradation

Control measures
Construction of tanks,ponds ,dams,reservoirs and wells to provide irrigation facilities

iii. Earthquake:
 It is a sudden shaking of the earth.
 It is a sudden vibration caused on the earths surface.
Causes:
 Movement of the earth’s tectonic plates.
 Sometimes due to friction,these plates are not able to slip in their natural manner.
Control measures
Resistant buildings in the earth quake prone areas.


iv. Cyclones:
 Cyclones are intense storms that develop over warm tropical seas.

The main dangers from cyclones are very strong winds,torrential rains and high strom tides.
Mitigation measures:
 Installation of early warning systems
 Developing shelter belts
 Developing community cyclone shelters construction of permanent houses.




3. Explain natural and man made impacts on environment

NATURAL AND MAN MADE IMPACTS ON ENVIRONMENT
Man uses the natural resources to make comfortable life to him and his generations. The water we drink, the air we breathe and the places where we live are getting polluted every where. In addition to his activities the nature has also made some destruction in the nature environment. The two main sources of pollution are:
(1) Natural sources of pollution
(2) Man made (or) Anthropogenic sources of pollution
Types of Environmental pollution:
The five types of pollution are
1. Air pollution
2. Water pollution
3. Land or soil pollution
4. Radio active pollution
5. Noise pollution
Impacts of Natural sources of pollution:
Some of the natural sources of pollution are:
i) Forest fires produce more smoke and trace gases into the atmosphere.
ii) Explosive Volcanic eruptions can inject more SO2, smoke, particulate matter and trace gases.
iii) Dust storms are the main cause for wind blow dust in the air.
iv) Natural contaminants present in the air like bacteria, spores, cysts and pollens are more dangerous when inhaled.
v) Carbon monoxide will be produced from the breakdown of methane gas in the marsh lands.
vi) Spraying of salts from oceans.
vii) Electrical storms produce oxides of nitrogen in the atmosphere which leads to ozone depletion.
Impacts of Man made sources of pollution:
The pollution of water, air and land are created and developed every day. They are made more complicated due to rapid growth of industries and population. Some of the anthropogenic sources of pollution are
1. Industrial development
2. Rapid growth of Automobiles
3. Uncontrolled population growth
4. Deforestation
5. Over exploitation of natural resources
6. Use of fertilizers, pesticides etc., in agricultural activities
7. Mining activities
8. Nuclear explosions
Impacts on Atmosphere:
 The dust and carbon particle make our cities dirty, spoil our material goods.
 Coal smog reduces visibility and is a major cause of traffic accidents.
 Inhalation of asbestos fibers causes a serious occupational and health problem (asbestosis), which leads to cancer and even death.
 The exhaust gas of automobiles contains more amount of unburnt fuel with more carbon monoxide. Inhalation of carbon monoxide in human beings leads to carboxy hemoglobin, which carries the oxygen carrying capacity of blood.
 The emissions from various types of industries and automobiles contain Sulphur-dioxide and nitrogen oxides. These gases combine with rain, smog and fog form acid rain.
 Release of CFC into the atmosphere causes depletion of ozone layer. That makes more health problems such as skin cancer and eye disorders in human beings.
 The release of air pollutants into the atmosphere increase the atmospheric temperature, known as global warming. The major effects are melting of ice caps, rising in sea levels and variation in seasons.
Impacts on Land:
 Disposal of industrial effluents and domestic wastes on land causes loss of its fertility.
 Removal of the top soil of land causes low fertility for crop production.
 Deforestation, the process of changing land use from forestry to a non forest use, is threatening the existence of many species.
Impacts on Water:
 Change in colour will affect the usage of water and growth of plants and organism of water.
 The dissolved oxygen content of the water body is reduced by organic substances.
 The water becomes unfit for drinking and other purposes because of inorganic substances.
 Oil and other lubricants will affect the self purification of the water body.
 Enrichment of nutrients (Eutrophication) from surrounding watershed affects the penetration of light through the water, causing damage to the characteristics of that water and aquatic life.
 Sewage disposed into water bodies’ results in many water borne infectious diseases to the human beings. The different types of organisms and water borne diseases are
Water Borne Diseases Responsible Organism
Typhoid, paratyphoid, Diarrhoea, Cholera, Bacillary dysentery Bacteria
Amoebiasis, Giardiasis Protozoa
ViralHepatitis (Jaundice), Poliomyelitis Virus
Round worm, hookworm, threadworm Helminths

 Disposal of coolant water used in industries increase the temperature of the surface water. This increase in temperature affects the aquatic ecosystem.
 More amounts of nitrates in water due to the application of artificial fertilizer in agricultural lands can cause methemoglobinemia known as blue baby disease.

4. Briefly explain the sustainable development.
CONCEPT OF SUSTAINABLE DEVELOPMENT
In the year 1992, the United Nations Conference on Environment and Development (UNCED) held at Rio de Janeiro, recognized the pressing environment and development problems of the world. It produced a global program of action for sustainable development into the 21st century by adapting Agenda 21. According to the Agenda 21, the countries should adopt national strategies for sustainable development, which should provide a balance in the needs of plans and policies of society, the economy, and the environment of the country.
The first principle of Rio declaration is the sustainable development. The Rio declaration states that, ‘human beings are at the centre of concern for sustainable development. They are entitled to a healthy and productive life in harmony with the nature. Every generation should leave air, water and soil resources without any pollution as pure as it came to the Earth”.
Accordingly Sustainable Development is defined as ‘the development to meet the needs of the present without compromising the ability of future generations to meet their own needs’. Sustainable Development must balance the needs of society, the economy and the environment.
The natural resources must be used in such away that, its utility will not limit their availability of water to the future generations. Sustainable development of water resources require the use of renewable water resources that are not diminished over the long term by that use.
The developed and most easily accessible renewable water resources are streams, lakes, rivers and aquifers that recharge quickly. The process of developing less accessible fresh water resources will be costly and is time consuming. The environmental and human costs of these projects can also be very high.
The three important components of sustainable development are:
1) Economic development (like industrial development, creating job opportunities, utilization of natural resources for developing the quality of life).
2) Community development (providing food, shelter, cloth, education and other essentials for the human beings).
3) Environmental protection (providing clean air, water and environment for the present and future generations and utilization of resources in a sustainable manner).
The frame work for the integration of developmental strategies with environmental protection is provided by the concept of sustainable development which includes the following.
1) Use of excessive resources is to be reduced with increasing resource conservation.
2) Waste minimization should be adopted with more recycling and reusing of materials.
3) Enhancing scientific, management of renewable resources.
Sustainability:
Sustainability can be defined as the ability of a society or ecosystem to continue functioning into the indefinite future without being forced into decline through complete loss of its strength or overloading of key resources on which that system depends.

Stability has two aspects which are almost opposite in nature.
(i) Resistance stability.
(ii) Resilience stability.
Resistance stability is the ability of a system to remain stable in the face of stresses and Resilience stability is the ability of the system to recover from the disturbance occurred due to the activities happened.
Characteristics of a sustainable development:
If a sustainable society is developed in the future, it is likely to have the following characteristics.
(i) All the material processes will be designed to be of cyclic nature.
(ii) There will not be any waste material or pollution of air, water, land and environment.
(iii) The output from one system will be used as inputs to other systems.
(iv) Only renewable energy will be used in the society, either or in the forms of hydro power, wind power, solar power and biomass.
(v) The human population will be either stable in size or gradually declining.
Major issues of Sustainable Development:
Some of the vital issues of environmental problems facing the developing countries are explained as follows:
(a) Land: Deforestation and desertification are the major terrestrial problems that are drastically caused by the factors such as overgrazing, massive land clearing and reduction in agricultural productivity. These factors in turn promote serious environmental issues such as increased flooding, sedimentation and silting up of dams and reservoirs. The problem is further complicated by the burning of forest woods for fuel by the rural population who are not affordable for other fuels thereby contributing for the rapid depletion of wild life reserves and ecological imbalance. The gradual extinction of plant and animal species that occurs at an accelerated pace is yet another serious problem which might cause multidimensional and irreparable loss to the future human society and also biodiversity.
(b) Pollution: Environmental pollution that is mostly caused by urbanization and industrialization provides growing concern n all developing countries. The alarming status of air and water pollution in certain Indian metropolitan cities like Calcutta, Mumbai and Delhi are similar to that of in other developing countries. Improper waste disposal and unhygienic water resources along with poor sanitary conditions further version and aggravate the environmental issues in several developing countries.
Excess use of fertilizers and pesticides are the other crucial agricultural problems that heavily contribute to environmental pollution. Acid rain, ozone depletion and global warming have become the major global issues that would result in catastrophic impact on environmental conditions.
Suggested measures for sustainable development:
1) It becomes meaningful to understand the uncertainties in totality, before depending on the popular predictions made by the section of our scientists and bureaucrats about the drastic consequences global warming. If it is not able to conduct specific scientific studies for want to proper funding sources, it is suggested that our country should involve and associate with the modeling research programmes conducted by World Meteorological Organization (WMO) and Global Environmental Monitoring system (GEMS).
2) Implementation of energy conservation procedures by reducing distribution losses of electricity, increasing the operative efficiencies of agricultural pump sets and switching over to sodium lamps for lighting.
3) Proper finding of alternate sources of energy such as nuclear, solar, wind energies and natural gas.
4) Typical modifications in the agricultural techniques by minimizing the use of synthetic fertilizers and switching over to organic farming.
5) Conservation of existing forests and creation of new forests by aforestation.


5.Describe in detail about effects of water pollution on environment

Water pollution can be defined as “the presence of some foreign substances or impurities in water in such quantity as to constitute a health hazard by lowering the water quality and making it unfit for use”.
MAJOR SOURCE OF WATER POLLUTION:
Point sources and non-point sources (diffused sources) are the two types of sources.

a) Point sources:
The sources that pollute water bodies at a single location such as sewage channels are called point sources.
b) Diffused sources:
The sources that pollute water at unknown locations or scattered places are called diffused sources.
e.g. pesticides and fertilizers, mining and construction activities.
WATER POLLUTANTS:
a) suspended matter:
Domestic and industrial sewage are the main sources of suspended matter.
e.g. detergents, soaps, lubricating grease products.
b) Inorganic and organic compounds:
Example:acids, alkalis, metals and synthetic organic compounds, Industrial effluents from paper mills, tanneries and food-processing units.
c) Pathogenic organisms:
Pathogenic organisms such as bacteria, viruses, protozoa forms and helminthic worms are the important pathogenic pollutants that are usually found in the polluted domestic sewage, agricultural runoff, industrial effluents and waste water from animal- slaughtering houses, thus causing environmental stress.
d) Thermal discharges:
The heated water from several power plants and thermal
Industries are pumped into the nearby water bodies and also
wet lands.

Causes of water pollution
i)domestic sewage
ii)industrial effluents
iii)thermal pollution
iv)oil pollution
v)radio active pollution

Effects of water pollution
i)water borne diseases
ii)effects of organic pollutants
iii)effect of sediments
iv)effects of organic chemicals
v)effect o0f pesticides
vi)effect of radio active pollutants
Control measures for water pollution:
a)sewage treatment
b)waste stabilization pond or oxidation pond
c)recycling.

6. Write in detail about the influence of air pollution.
Air pollution:
It may be defined as any atmospheric condition in which certain substances are present in such concentrations they can produce undesirable effects on man and his environment.
AIR POLLUTION DUE TO INDUSTRIES AND VEHICLES:
 Industrial and auto mobile emission have been identified as primary contributors of major portion of air pollution.
 Industrialization which represents an inevitable constituent in civilized modernization.
 Vehicles using fossil fuels cause air pollution through the emission of toxic pollutants into the atmosphere.
 The elegant beauty of TajMahal which is the glorious and fantastic Monument of international repute is getting degraded and deteriorated by the loss of its fascinating beauty due to the constant emissions of refinery industries situated at Mathura.
 Analysis of the chemical composition of emissions of both industries and automobile vehicles have revealed the following toxic pollutants.

SUSPENDED PARTICULATE MATTER:
 Particulate matter primarily consists of suspended or dispersed matter solid or liquid particles than 10 µm called aerosols.
 Sources – Wind-blown soil dust, evaporated sea-spay droplets and volcanic eruptions, combustion of fossil fuels.

Pollutants
Sources Health effects
Carbon monoxide Incomplete fuel combustion(two stroke engines and 3 wheelers) Aggravates heart disorders, affects central nervous system and O2 carrying capacity
Nitrogen oxides Fuel combustion of motor vehicles and furnaces Irritation and inflammation of respiratory tract
Oxidants and ozone Emission from motor vehicles Photochemical reaction s of nitrogen oxides
Lead

Emissions from motor vehicles Extremely toxic, affects nervous system and blood, causes hyper tension, impairs mental development in children
Volatile hydro carbons Disposal of solid wastes, partial combustion of carbonaceous fuels Cough, eye irritation and drowsiness.
Sulphur dioxide Burning of sulphur containing fuel like coal in power plants and oil by vehicles Irritation of eyes, nose and throat sneezing, coughing and nausea.
 These are found to be carcinogenic and stimulate serious respiratory disorders such as asthma and pneumonia.
Causes of air pollution:
i)industries
ii)automobiles
iii)forest fires
iv)oceans
v)agriculture
vi)marshes
vii)radioactive materials
viii)freons
Effects of air pollution:
i) effects of air pollution on human health
ii) effects on plants
iii) effects of air pollution on materials
iv) effects of air pollution on the stratosphere





7. In a detailed manner discuss the land pollution and its effects.
Land pollution:
It may be defined as “the contamination of the soil resulting in either reduction of its frtility or entry of contaminants in plants which subsequently enter the food chain and impart toxic or detrimental effect on the consumers.
Causes of land pollution:
i)soil erosion
ii)industrial waste
iii)agricultural waste
iv)urban waste
v)biological pathogens
vi)radioactive waste
effects of soil pollution:
i)effects of industrial pollutants
ii)effects of urban waste products
iii)effects of radioactive pollutants
control of soil pollution:
i) solid wastes may be treated by pyrolysis method
pyrolysis is the nbreakdown of solid wastes by heat in the absence of oxygen
ii)sanitary land fills:
dumping of untreated wastes in the layers of earth and then covering it with soil should be adopted.
• Recycling and reuse of wastes,like paper,plastic,glass,metals,etc should be encouraged
• The garbage and night soil can be converted into compost manure
• Natural soil micro-organisms should be preferred over pesticides and incsecticides
• Bio degradable organic waste should be used for generation of biogas
Soil conservation:
Conserving healthy soil and restoring degraded soils will require rethinking on modern agricultural and other land use practices

8.Explain the factors which develops the environment.
The two major criteria i.e. a project should maximize economic returns, and it should to technically feasible.
There are two different aspects of impacts of development on environment.
i.e. Local and global impacts.
Every developmental activity be it the construction of hydel projects, thermal power plants, urbanization, communication projects, industry, or agriculture has some impacts on the environment.


INDUSTRY:
 The air, water, and hazardous waste pollution by industries has now become the biggest environmental problem.
 The emission and effluents of some of the industries are extremely polluting and dangerous such as industries, manufacturing pesticides, fertilizers, pulp and paper, distilleries, dye manufacture etc.
 These pollutants could have several synergistic-long term effects.
THERMAL PLANTS:
 The thermal plants affect the occupational safety and health due to heat, noise, dust and chemical pollutants.
 The immense quantities of fly ash produced by these thermal plants also cause degradation of soil and conversion of useful agricultural land as dumping ground of this fly ash.
 The thermal plants could affect the quality of life, habitat of endangered species of wild life or plants, sites/monuments of historical and cultural importance up to 25 km radius.
 The cooling waters which have a temperature higher than that of natural water bodies, when disposed off in these bodies, results in loss of dissolved oxygen and thus, adversely affects aquatic life.

HYDEL PROJECTS:
Earlier hydel projects were considered to be least polluting and with minimum environmental effects.
Some of the effects on environment are:
Heath effects:
Hydel projects result in formation of large reservoirs.
The large water bodies are known to result in introduction of water borne diseases in an area such as malaria and schistosomiasis epidemics.
Plant genetic resources:
(i) The recent food plant like wheat, rice, maize, pulses, oilseeds, fruits and vegetables have been developed from their wild and weedy relatives.
(ii) The formation of reservoirs upstream dams results in inundation in destruction of biotic resources of these areas for short term gain.
Aquatic resources:
 Most of the dams, generally, do not have an arrangement for fish ladders or mechanisms or lift fish to reach their breeding spots.
 The dams have therefore, adversely affected the fish production, a rich protein source.
 Water logging and salinity problems in irrigated soils:
 About 10 million hectare irrigated area under agriculture is affected by water-logging and salinity.
 Most of this is due to inadequate attention to drainage works in irrigation projects and indiscriminate use of water for irrigation.
 Deforestation and soil conservation:
 Hydel projects require extensive road building activity, new settlements and industries resulting in destruction of forest areas and stable slopes of hills resulting in frequent land slides, these further results in increased sedimentation, flash floods and loss of land fertility.
URBANIZATION
 The shifting or rural population to the cities has severely overstrained infrastructure in the existing urban areas.
 The local authority and the government as a result, are finding it difficult to provide adequate roads, water supply, sewage treatment plants, schools and hospitals.
 The non point pollution from cities i.e. runoff washing away and solid waste from roads into nearby surface waters is yet to attract attention of the regulatory agencies.


COMMUNICATION PROJECTS:
 The increasing road infrastructure in the country is encroaching more and more of agricultural and forest land.
 It is also affecting the aesthetics, forest density, crops and is causing major health problems due to air pollution specifically in built up areas.
 The in adequate drainage systems under the roads has also contributed to flooding and degradation of soils in a big way

9. Discuss the science of environment with attention to your branch of engineering.
ROLE OF ENGINEERS IN DEVELOPMENTAL PROJECTS:
It is the moral obligation and responsibility of engineers who are associated with the developmental projects to be aware of the consequences and impacts of the proposed projects on the environmental implications.
They have to strictly adhere to the rules and regulations that are enforced in environmental policies for the complete protection and maintenance of ecological balance in the sites where the proposed projects are to be constructed.
Ethical implications, that provide highest value for the sustained maintenance of biodiversity and ecological balance which in turn benefits the human welfare.
Exposure of knowledge on the biological characteristics of an environment would provide better insight and guidance to the engineers for handling the projects in an eco-friendly manner.
10. Discuss briefly about the environmental impacts on marine habitat.
Marine
Marine pollution:
It is defined as the discharge of waste substances into the sea resulting in harm to living resources,hazards to human health,hindrance to fishery and impairment of quality for use of seawater.
Causes of marine pollution:
I) Oils
II) sewage
III) chemicals
IV) radioactive wastes
V) thermal pollutants
VI) metallic pollutants
Effects of marine pollution:
i) Physical effects of oil in water
 reduction in dissolved oxygen
 reduction in light penetration
ii) Effects of oil pollution on marine ecosystem
 smothering coats of oils kill lichens and algae along the sea shores
 extensive spreading of oil affects the floating plantation and marine life severely.
 Waste from oil refineries and discharged petroleum from ships causes heavy damage to fishery.
 Oil spilling causes lethal toxicity to aquatic flora
 Direct oil coatings render the fish unable to respire and clog their gill slits.
 Aromatic hydrocarbons in oil are carcinogenic and adversely affect plant metabolism.
 The thin film of oil on the surface of water is called oil slick. oil slicks damage marine life .the oil slick damages the mangrove plants.
 Coral reefs, the gardens of the sea, are damaged by oil slick.
 Sea cows, the aquatic mammals, die off due to oil slick.
 The sea birds are much affected by oil pollution and die.
 Fish and shellfish production facilities are affected by oil slicks. the most important commercial damage comes from tainting, which imparts an unpleasant flavor to fish and seafood.
 Birds are specially vulnerable to damage from oilspill.the spilled oil breaks down their natural coatings of oils and waxes which shield the birds from marine water. Ultimately they lose their insulation, start shivering and may freeze to death in winter.

ENVIRONMENTAL SCIENCE & ENGINEERING
UNIT-III

Part-A (2 Marks)

1. Define sewerage system?
A sewerage system consists of a network of sewer pipes laid in order to carry the sewage from individual homes to the sewage treatment plants. This network of sewers may consist of house sewers, lateral sewer, branch sewer, main sewer etc.
2. Mention types of sewerage system?
a) Combined system
b) Separate system
c) Partially separate system.
3. What are the components of sewerage system?
a) Sewer pipe
b) Sewage treatment plant
c) Manholes
d) Catch basin.
4. What are the tests involved in chemical analysis of sewerage?
Chemical analysis is carried out on sewage in order to determine its chemical characteristics. The tests involved in chemical analysis of sewerage are:
a) Total solids, suspended solids and settleable solids.
b) pH value
c) Chloride content
d) Nitrogen content
e) Presence of fats, grease and oil
f) Sulphides, sulphates & Hydrogen sulphide
g) Dissolved Oxygen
h) Chemical Oxygen Demand
i) Biological Oxygen Demand
5. What are the tests involved in physical analysis of sewerage?
Physical analysis is carried out on sewage in order to determine its physical characteristics. The tests involved in chemical analysis of sewerage are:
a) Turbidity
b) Colour
c) Odour and
d) Temperature.
6. Define pH value?
pH value is an indicator of alkaline or acidic nature of sewage. If the pH value is less than 7, the sewage is acidic and if the pH value is greater than 7, the sewage is alkaline. The lesser is the pH value, the lesser is the alkalinity.
7. Define dissolved oxygen?
The determination of dissolved oxygen present in the sewage is very important, because while discharging the treated sewage into some river stream, it is necessary to ensure at least 4ppm of D.O in it. Otherwise, fishes are likely to be killed, creating nuisance near the vicinity of disposal. To ensure this, D.O tests are performed during sewage disposal treatment processes.
8. Mention about sewerage decomposition?
Most of the organic matter present in sewage is unstable and decomposes readily through chemical as well as biological actions. Till the advent of biological methods, chemical treatment of sewage was, therefore, being adopted to remove the organic matter from the sewage. However after the advent of biological degradation method, this type of treatment has become our foremost choice.
The organic matter, which is decomposed by bacteria, under biological action, is called biodegradable organic matter. Most of the organic matter present in sewage is biodegradable, and hence undergo biological decomposition, which can be divided into two types, i.e
i) aerobic decomposition called aerobic oxidation
ii) Anaerobic decomposition called putrefaction.
9. What are the different methods involved in sewerage population forcasting?
a) Arithmetical increase method
b) Geometrical increase method
c) Incremental increase method
d) Decreasing rate method
e) Simple graphical method
f) Comparative graphical method
g) Master plan method
h) The apportionment method
i) The logistic curve method.
10. Define run-off process?
Runoff process for a given precipitation, the evapo-transpiration, initial loss, infiltration and detention storage requirements will have to be first satisfied, the excess precipitation moves over the land surfaces to reach smaller channels. Flows from several small channels join bigger channels and flows from these in turn combine to form a larger stream, and so on, till the flow reaches the catchments out let. This phenomenon is called run-off process.
11. Mention the types of sewerage characterization?
The types of sewerage characterization are:
a) Physical
b) Chemical
c) Bacteriological (biological).
12. What are the principles of sanitation?
a) The waste matters like garbage and sewage should be removed as early as possible after its formation.
b) The waste matters after collection should be treated within four hours and the effluent should be disposed off immediately.
c) The floors and furniture in a house should be cleaned regularly
d) The buildings should be made damp proof
13. Write short notes on minimum size of sewer.
The minimum size of sewer depend upon the practice followed in the locality. Usually the sewers of 100mm diameter are allowed upto a maximum length of 6m.but when the length of sewer line exceeds 6m , a sewer of minimum diameter 150 mm is allowed.
14. What are the advantages of circular shape of sewer?
 This gives least diameter
 It has maximum hydraulic mean depth
 It prevents possibility of deposit anywhere being of circular curvature
 It is very economical
 The discharge is more or less constant in separate system
 It has sufficient self cleaning velocity
 The inner surface is smooth hence the flow of sewage is uniform and there is no chance of deposition of suspended particles.
 The circular sewers are easy too construct.

15. Write short notes on stone ware or vitrified clay pipes.
The stoneware pipes are manufactured from vitrified clay by moulding and burning to a temperature of 1200oC in kiln. During the process of burning, sodium chloride is spread on the surface of the pipe so that a glass like appearance comes on the pipes. These are generally used in domestic sanitary fittings.
16. Define the term Design Period.
The time required to run any unit to its full capacity after its construction and installation is known as design period. The unit which has been constructed today will need to serve the future population also. So it should have adequate capacity to cope up with the future population.
17. Write short notes on maximum velocity in sewer
The suspended particles may impart scouring action to the inner surface of the sewer and may damage the sewer section so the maximum permissible velocity should be such that no scouring action may takes place. The maximum velocity in brick line sewer is 150 to 250 cm/s, for cement concrete sewer 250 to300 cm/s, for stoneware sewer 300 to 450 cm/s.
18. What are the various gradients present in sewer lines?
a) slope of the ground
b) minimum and maximum velocities
c) diameter of sewer and quantity to be discharged
d) Type of land
19. What are the requirements of good sewer joint?
a) construction should be such that tree roots cannot penetrate.
b) It should be cheap and economical.
c) It should be easy to construct.
d) It should be flexible in nature so that it is not damaged due to slight settlements in the sewer line.
e) It should resist acidic, alkaline or gaseous action in sewage.
f) It should be non absorbent and durable.
g) It should be water light.
20. Define manhole.
A manhole is a structure constructed to provide access to the sewer for facilitating inspection, cleaning or usual maintenance operations.
21. What are the various methods adopted for the ventilation of sewers?
a) use of manhole with chemicals
b) Use of manhole with gratings.
c) Proper construction
d) Proper design
e) Proper house drainage system
f) Ventilating columns or shafts.
22. What are the precautions to be taken while cleaning sewers?
a) Before removing the cover of the manhole, the space should be fenced to avoid accidents.
b) After removing the cover, one should wait half an hour for the sewer to get ventilated before attempting to clean it.
c) Tests should be made for sulphur – wetted hydrogen and inflammable gases.
d) The first man to enter the sewer should be secured by a life line through out the period of work in the sewer, and there should be at least two men outside for rescue work. Only lamps or electric lamps of approved pattern should be used by men working in the sewers. Smoking should not be permitted in or around the sewers. Warning signals should be provided suitably.
23. What is meant by the term Per Capita Demand?
The annual average amount of daily water required by one person and includes the domestic use , industrial use and commercial use , public use , wastes, thefts , etc, .It expressed as
Per capita demand(q) in liters per day per head=Total yearly water requirement of the city in liters/365xDesign population

24. What are the objects served by the manhole?
a) They enable inspection, cleaning and maintenance of sewer.
b) The obstructions in sewage flow are collected in the manhole and brought to the surface.
c) The facilitate joining, changing direction or alignment of sewers.
d) Sewage from various sewers and from various directions is sometimes collected in the manhole.
e) A manhole fitted with perforated covers allows for ventilation. Sewer gases escape through the perforation.
f) The manhole helps to lay sewer lines of convenient lengths.
25. Enumerate the sources of wastewater.
Sources of water:
The major sources of water available on the earth can be classified into the following categories:
a) Surface sources
(i) Ponds and lakes
(ii) Streams and rivers
(iii) Storage reservoirs
b) Subsurface sources
(i) Springs
(ii) Infiltration galleries
(iii) Infiltration wells
(iv) Wells

Part-B (12 Marks)
1. Describe in detail about the water demand for the public water supply system.
An average person may consume no more than 5 to 8 litres a day in liquid and solid foods, including 3 to 6 liters in the form of water , milk and other beverages. Total water requirement may be divided into the following five categories.
o Residential or Domestic use
o Institutional use
o Public use or civic use
o Industrial use
o Water system losses
Residential or domestic use

The residential or domestic use includes water requirements for drinking, cooking, bathing,washing of clothes,utensils and house,and flushing of water closets. provision is sometimes made for domestic animals.IS:1172-1957 recommends a per capita water consumptions of 135 lit/day .table 5.5 gives the break of water requirements per head per day,for all the 5 categories mentioned above.table 5.6 gives the water requirements for domestic animals. It should be noted that water required for lawn sprinkling and for residential gardens is over and above the values given in table

s.no description Amount of water( in ltrs per head per day)
1 Bathing 55
2 Washing of clothes 20
3 Flushing of W.C 30
4 Washing the house 10
5 Washing of utensils 10
6 Cooking 5
7 Drinking 5
Total 135 ltrs

Public or civic use

Water required for public or civic use may be for the following purposes: 1. road washing, 2.sanitation, 3. public parks and 4.fire fighting.. for road washin in municipality area a provision of 5 ltr per head per day is made. Similarly , for sanitary purposes , such as cleaning public sanitary blocks , flushing sewer systems etc..,
A provision of 3-5 ltr per head per day may be made. Water required for maintaining public parks etc… may be 2-3 ltrs per sq mtr per day.

Water for institutional needs

Institution Water requirement
(ltrs per heal per day)
1. Hospitals (including laundry)
a. no of beds exceeding 100
b. no of beds not exceeding 100
450(per bed)
340(per bed0

2. hotels 180(per bed)
3. hostels 135
4.Nurse’s homes and medical quarters 135
5. boarding school/ colleges 135
6.restaurents 70(per seat)
7. air ports and sea ports 70
8.junction station and intermediate stations where mail and express stoppage (both railways and bus stations is provided) 70
9. terminal stations 45
10. intermediate stations
(excluding mail and express stops) 45
11. day schools / colleges 45
12. offices 45
13. factories 45
14cinema , concert halls and theatres 15


Industrial need

Industry Unit of production Water reqirement in
Kilolitres per unit
1. automobile Vehicle 40
2. distillery Kilolitre(proof alcohol)
122-170
3. fertilizer Tonne 80-200
4. leather 100 kg (tonne 4
5. paper Tonne 200-400
6. special quality paper Tonne 400-1000
7. straw board Tonne 70-100
8. Petroleum refinery Tonne(crude) 1.5-2
9. steel Tonne 200-250
10. sugar Tonne( cane crushed) 1-2
11. textile 100kg(goods) 8-14



Water system losses
Losses from a water distribution system consists of (1)leakage and overflow from service reservoirs, (2)leakage from main and service pipe connections, (3)leakage and losses on consumers premises when they get un-metered house hold supplies,( 4)under registration of supply meters, and (5) large leakage or wastage from public taps. Losses in the supply lines are mainly due to defective pipe joints, cracked pipes, and loose valves and fittings. In the case of a well maintained and fully metered water distribution system, the losses may hardly exceed 20% of the total consumption. In a system where the supply is partly metered (for domestic connections) and partly un-metered (for municipal taps) , the losses may be up to 50% of the total supply.


2. Write about estimation of storm runoff sewerage water?
Of the precipitation upon a catchment area some runoff immediately appear instreams or flood flow ; some evaporate from land and water surface; some known as inter caption are caught on leaves of vegetation; and some termed as infiltration, seep into the ground. The total flow in a surface stream is due to surface runoff and runoff derived from underground water which is known as the base flow.
Factors affect run off
• Infiltration
• Rainfall characteristics
• Soil characteristics
• Evaporation
Formulation of storm run-off- The rational method .
This consist of considering all factors which contribute to maximum run off and combining them to obtain an expected amount .the rainfall intensity may be designed for is that which has a duration equal to the time of concentration.
Characteristics of the drainage area in question must be carefully studied so far as they affect direct run –off and time of concentration. The quantity of storm flow can be given by the following formula ;
Q=1/36 aCR
Where,
Q= storm flow in m3/sec
A= drainage area considered in hectares
C=impervious co-efficient depends on the nature of the area.
R=intensity of rainfall in cm/hour.
Empirical formulas:
There are many formulas developed for finding out runoff. A few of these are occasionally used. The Burkli-Ziegler formula is
Q=1/36 (aCR) (S/a)1/4
Where,S is the average slope of the ground in meter per 1000 meters and other terms are same as used in rational formula.
Q=1/36 (aCR) (S/A)1/5
Where,
Q= storm flow in m3/sec
A= drainage area considered in hectares
C=impervious co-efficient depends on the nature of the area.
R=intensity of rainfall in cm/hour


3. Explain design period and population forecasting in sewerage system.
Design period in sewerage system:
A sewerage scheme involves the laying of under ground sewer pipes and construction of costly treatment units, which cannot be replaced or increased in their capacities easily or conveniently at a later date. For example, addition of sewer pipes at a future date cannot be accomplished with out digging the roads and disrupting the traffic. In order to avoid such future complication and to take care of the future expansion of the city and consequent increase in the quantity of sewage product, it is necessary to design the various component of the scheme larger than their present day requirement of such sizes as to serve the community satisfactorily for a reasonable number of years to come this future period for which the provision is made in designing the capacities of the various components of the sewerage scheme is known as the design period.

Population forecasting in sewerage system:

The following are the standard methods by which the forecasting of population is done.
• Arithmetical increase method
• Geometrical increase method
• Incremental increase method
• Graphical Extension method
• Graphical Comparison method
• Master plan method
• Ratio and correlation method
• Growth composition analysis method

a) Arithmetical increase method
In this method the rate of increase in population is assumed constant. So the average increase in population is worked out from the record of past decades then this average is added to the present population and the population of successive decades to get the required population. This method is based on the assumption that the population is increasing at a constant rate.
Pn=P + n I
b) Geometrical increase method
In this method it is assumed that the percentage increase in population remains constant from the available census records. This percentage increase is worked out then the population of successive future decades is calculated.
Pn = P [1 + Ig/100]n
c) Incremental increase method
(i) This method is combination of the above two methods and therefore give the advantages of both arithmetic and geometric increase method.
(ii) In this method the average increase per decade is found out as in arithmetical increase method to this is added the average of the net incremental increase once for every future decade.
Pn=P + n I +[n(n + 1)/2]r
d) Graphical Extension method
In this method a curve is drawn between the population P and time T, with the help of census data of previous few decades, so that the shape of the population curve is obtained-upto the present period. The curve is then carefully extended from the present to the future decades. From extended part of the curve, the population at the end of any future decade is approximately determined.
e)Graphical comparison method
This method is a variation of the previous method. It assumes that the city under consideration will develop as similar cities developed in the past. The method consist of plotting curves of cities that, one or more decades ago, had reached the present population of city under consideration.




4. Write about characterization of water quality.
Designated-Best-Use Class of water Criteria
Drinking Water Source without conventional treatment but after disinfection A • Total Coliforms Organism MPN/100ml shall be 50 or less
• pH between 6.5 and 8.5
• Dissolved Oxygen 6mg/l or more
• Biochemical Oxygen Demand 5 days 20°C 2mg/l or less

Outdoor bathing (Organised) B • Total Coliforms Organism MPN/100ml shall be 500 or less pH between 6.5 and 8.5 Dissolved Oxygen 5mg/l or more
• Biochemical Oxygen Demand 5 days 20°C 3mg/l or less

Drinking water source after conventional treatment and disinfection C • Total Coliforms Organism MPN/100ml shall be 5000 or less pH between 6 to 9 Dissolved Oxygen 4mg/l or more
• Biochemical Oxygen Demand 5 days 20°C 3mg/l or less

Propagation of Wild life and Fisheries D • pH between 6.5 to 8.5 Dissolved Oxygen 4mg/l or more
• Free Ammonia (as N) 1.2 mg/l or less

Irrigation, Industrial Cooling, Controlled Waste disposal E • pH betwwn 6.0 to 8.5
• Electrical Conductivity at 25°C micro mhos/cm Max.2250
• Sodium absorption Ratio Max. 26
• Boron Max. 2mg/l
Below-E Not Meeting A, B, C, D & E Criteria

5. The following is the population data of a city, available from past censes records. Determine the population of the city in 2021 by
a. Arithmetical increase method.
b. Geometrical increase method.
c. Incremental increase method.
YEAR 1931 1941 1951 1961 1971 1981 1991
POPULATION(P) 12000 16500 26800 41500 57500 68000 74100
5.
Year Population Increment/decade %increment/decade Incremental increase
1931 12000 4500 37.50 +5800
1941 16500 10300 62.42 +4400
1951 26800 14700 54.85 +1300
1961 41500 16000 38.55 -5500
1971 57500 10500 18.26 -4400
1981 68000 6100 8.97
1991 74100
Total
Average 62100
62100/2=10350 220.55
220.55/6=36.76 +1600
1600/5=320

Arithmetical increase method
Pn=P + n I
Where,
P=population in1991=74100
n= number of decades=2021-1991/10=3
I= avg increase per decade=10350
Pn=74100 + 3(10350)=105150


Geometrical increase method.
Pn = P [1 + Ig/100]n

Where Ig=avg percent increase per decade=36.76%(from table)
Pn = 74100 [1 + 36.76/100]3
Pn=189537
Incremental increase method. Pn=P + n I +[n(n + 1)/2]r


Where ,
I=10350
r=avg incremental increase =320(from table)
Pn=74100+ 3 (10350) +[3(3 + 1)/2]320=107070


6. Explain effluent standard.
Parameters Standard Values Method for Examination
1. pH value 5.5-9.0 pH Meter
2. Total Dissolved Solids (TDS)
not more than 3,000 mg/l depending on receiving water or type of industry under consideration of PCC but not exceed 5,000 mg/l
• not more than 5,000 mg/l exceed TDS of receiving water having salinity of more than 2,000 mg/l or TDS of sea if discharge to sea Dry Evaporation 103-105 °C, 1 hour
3. Suspended solids (SS) not more than 50 mg/l depending on receiving water or type of industry or wastewater treatment system under consideration of PCC but not exceed 150 mg/l Glass Fiber Filter Disc
4. Temperature not more than 40°C Thermometer during the sampling
5. Color and Odor not objectionable Not specified
6. Sulphide as H2S not more than 1.0 mg/l Titrate
7. Cyanide as HCN not more than 0.2 mg/l Distillation and Pyridine Barbituric Acid Method
8. Fat, Oil & Grease (FOG) not more than 5.0 mg/l depending of receiving water or type of industry under consideration of PCC but not exceed 15.0 mg/l Solvent Extraction by Weight
9. Formaldehyde not more than 1.0 mg/l Spectrophotometry
10.Phenols not more than 1.0 mg/l Distillation and 4-Aminoantipyrine Method
11.Free Chlorine not more than 1.0 mg/l lodometric Method
12.Pesticides not detectable Gas Chromatography
13.Biochemical Oxygen Demand (BOD) not more than 20 mg/l depending on receiving water or type of industry under consideration of PCC but not exceed 60 mg/l- Azide Modification at 20 °C , 5 days
14.Total Kjedahl Nitrogen (TKN) not more than 100 mg/l depending on receiving water or type of industry under consideration of PCC but not exceed 200 mg/l Kjeldahl
15.Chemical Oxygen Demand (COD) not more than 120 mg/l depending on receiving water of type of industry under consideration of PCC but not exceed 400 mg/l Potassium Dichromate Digestion
Heavy metals:
1. Zinc (Zn)
not more than 5.0 mg/l Atomic Absorption Spectro Photometry Direct Aspiration or Plasma Emission Spectroscopy ; Inductively Coupled Plama : ICP
2. Chromium (Hexavalent) not more than 0.25 mg/l
3. Chromium (Trivalent) not more than 0.75 mg/l
4. Copper (Cu) not more than 2.0 mg/l
5. Cadmium (Cd) not more than 0.03 mg/l
6. Barium (Ba) not more than 1.0 mg/l
7. Lead (Pb) not more than 0.2 mg/l
8. Nickel (Ni) not more than 1.0 mg/l
9. Manganese (Mn) not more than 5.0 mg/l

7. Explain characterization and composition of sewerage and their significant.
The characteristics of sewerage are as follows:
1. Physical characteristics
2. Chemical characteristics
3. Bacteriological characteristics
1. Physical characteristics:
a) Specific gravity:
The specific gravity of the sewerage is slightly more than that of water.
b) Colour:
The fresh sewerage has yellowish grey colour. As the decomposition goes on, the colour also goes on changing. It becomes black when the sewage attains the septic stages.
c) Odour:
The fresh sewage has oily odour. But the stale or septic sewage has offensive odour due to hydrogen sulphide and to other gases.
d) Temperature
The temperature of sewage is slightly higher than the temperature of water supplied. While passing through the conduits the temperature rises and the bacterial activity starts.
e) Turbidity:
The turbidity of sewage is due to the suspended particles.
f) Solids
The solid matters may be suspended, dissolved or in colloidal states. Again, the solids may be inorganic or organic. The inorganic solids are grit, sand etc and organic solids are cellulose, sugar, starch etc.
2. Chemical characteristics:
The following are the chemical characteristics of sewerage:
a) The fresh sewerage is alkaline in nature, and the septic sewerage is acidic in nature.
b) Organic compound:
i) Nitrogenous compounds: It includes urea, proteins, amino acids etc.
ii) Non Nitrogenous compounds: It includes fats, soaps, carbohydrates etc.
c) Inorganic compounds: It includes sand, gravel, grit etc.
d) Colloidal matters: it includes silt, clay etc.
e) Fresh sewage is alkaline and favors bacterial action.
f) The solids present in sewage constitute 0.8 -1% by weight.
g) The solids may be suspended, dissolved, colloidal or settable.
h) The substances are complex, organic derived from urine or inorganic chemicals
3. Bacteriological characteristics:
a) Bacteria:
i) Pathogenic bacteria: This is the root of all water borne diseases.
ii) Non pathogenic bacteria: this is practically harmless to human being.
iii) Aerobic bacteria: it helps the decomposition of sewage in oxidation ponds, lagoons etc.
iv) Anaerobic bacteria: It helps the decomposition of sewage in septic tank, cesspool etc.
v) Facultative bacteria: this bacteria has no function in sewage treatment.
b) Microorganisms:
The microorganism like algae, fungi and protozoa help the process of decomposition of sewage by photosynthesis or by breaking the organic compounds.

8. Write about sources of water.
Sources of water:
The major sources of water available on the earth can be classified into the following categories:
Surface sources
Ponds and lakes
Streams and rivers
Storage reservoirs
Subsurface sources
Springs
Infiltration galleries
Infiltration wells
Wells
1. Ponds and Lakes:
A natural large sized depression formed within the surface of the earth., when gets filled up with water, is known as a pond or a lake. If the size of the depression is small, then it is called as a pond and when the size of the depression is large, then it is called as a lake.
The quantity of water in a lake is good and does not need much purification. The quantity of water from lakes is small. They are therefore useful for only small towns and hilly areas.
2. Streams and Rivers:
Small stream channels feed their waters to the lakes. If the quantity of water available is small, they cannot be used for water supply scheme. Rivers are the most important sources of water for public water supply schemes. Rivers may be perennial or non perennial. Perennial rivers are those in which the water is available throughout the year. It is used as source for public water supplies.
Sub Surface sources:
1. Springs
When under ground water reappears at the ground surface by percolation or by under ground pressure, then it is known as spring. The water of the spring may contain some types of salts or minerals. So, it should be tested before use. If required the water should be treated to make it suitable for drinking. This source is suitable for water supply in hilly town. The following are the different types of springs:
a) Gravity springs
b) Surface springs
c) Artesian springs.

2. Infiltration Gallery
They are horizontal tunnels constructed at shallow depths (3 to 5m) long the bank of the river. They are called as horizontal wells.
3. Infiltration wells:
Infiltration wells are the shallow wells constructed in series along the bank of the rivers in order to collect river water seeping through their bottom.
4. Wells:
A well is defined as artificial hole or pit made in the ground for the purpose of tapping water.
The following are the classification of different types of wells.
a) Shallow well
b) Deep well
c) Tube well
d) Artesian well.
9. Describe in detail about the water carriage system
In India, metropolitan cities and well developed cities are provided in this system. After large number of experiments, it was found that the water is only cheapest substance, which can be easily used for the collection and conveyance of sewage. Here, the use of human power for collection and disposal of sewage is completely eliminated. So this system is called as a water carriage system.
1. In this system the night soil gets mixed up with sufficient quantity of waste water forming sewage and is collected in a system of pipes and transported for subsequent treatment and disposal in a harmless manner without nuisance.
2. The sewage is conveyed in suitably designed and maintained sewers.
3. Garbage is collected and conveyed as in the conservancy system.
4. Storm water may be carried separately or may be allowed to flow with sewage.
5. The initial cost of installation of the water carriage system is very high and it becomes difficult to adopt it when financial resources are low.
6. However, the water carriage is a modern method and should be recommended wherever the development of the town is concerned.
Merits:
1. It is a hygienic method, because all excremental matter is collected and conveyed by water, no human agency is employed.
2. There is no nuisance in the streets because all the sewage goes in closed sewers underground. The risk of epidemics is reduced.
3. As only one sewer is laid, it occupies less space in crowded lanes.
4. Due to a greater quantity of sewage, self cleaning velocity can be attained even at lower gradients.
5. Buildings can be designed compactly as one unit.
6. The land required for disposal work is less.
7. The usual water supply is sufficient, no additional water is required.
8. This system does not depend on manual labour except when sewers get choked.
9. The sewage after treatment can be used for various purposes.
Demerits:
1. This system is very costly at the initial stages.
2. Maintenance of this system is costly.
3. During the monsoon season, a large volume of sewage has to be treated, whereas a very large volume has to be treated during the rest of the year.
10. In a town, it has been decided to provide 200litres / head / day. Estimate the domestic water requirements of this town in the year 2010 by projecting the population of the town by the incremental increase method from the data given below.
Year Population
1950 2,50,000
1960 4,80,500
1970 5,50,300
1980 6,38,600
1990 6,95,200



Year Populatoin Increment per decade Increment per Increase
1950 250000
1960 480500 230500
1970 550300 69800 (-)160700
1980 638600 88300 (+)18500
1990 695200 56600 (-)31700
Total Average 445200
445200 = 111300
4 (-)173900
(-)173300 =(-)57967
3

INCREMENTAL INCREASE METHOD
Pn=P + n I +[n(n + 1)/2]r


Where ,
I=111300
r=avg incremental increase =(-57967)(from table)
Pn=695200+ 2 (111300) +[2(2+ 1)/2](-57967)=743899

Hence water required in 2010 in liters/head/day=743899(200)=148.8 x 106 liters/day
=148.8 million liters/day




UNIT-IV
Part-A (2 Marks)
1. Define water supply?
For any living being, air, food, shelters are the primary needs of which water has the greatest importance. Water is required for various purposes.
a) For drinking and cooking
b) For bathing and washing
c) For watering of lawns and gardens
d) For heating and air conditioning systems
e) For growing of crops
f) For street washing
g) For fire fighting
h) For recreation in swimming pools, fountains
i) For steam power and industrial processes.
So, to meet the above demands, systemic water supply is necessary. The quantity of water required for domestic use mainly depends on the habits, social status, climatic conditions and customs of the people.
2. What are the sewerage materials?
The sewerage materials are brick, concrete pipes, pre-cast concrete pipes, cast-insitu reinforced concrete, salt glazed stone ware pipes, asbestos cement, iron & steel, plastic pipes, glass fibre reinforced plastic pipes and pitch fibre pipes.
3. Mention two advantages of steel Pipes?
a) Non- corrosiveness to most natural soil conditions.
b) Light in weight
c) Easy in cutting, drilling, threading and fitting.
d) Allowance of greater deflection upto 12degrees with mechanical joints.
4. Mention four advantages of cement concrete pipes?
a) Concrete pipes are relative easy with which the required strength may be provided.
b) Feasibility of adopting a wide range of pipe sizes.
c) Rapidity with which the trench may be opened and back filled.
d) Number of jointing methods is available depending on the tightness required.
5. Define RCC pipe.
RCC pipe is a conduit having different shape and size, which is made or casted from reinforced steel, concrete aggregates, cement and confirming to Indian standard specification.
6. What are the devices include in sewer appurtenances?
The devices include in sewer appurtenances are
a) Man holes
b) Drop manholes
c) Lamp holes
d) Clean outs
e) Street inlets called gullies
f) Catch basins
g) Flushing tanks
h) Grease and oil traps
i) Inverted siphons
j) Storm regulators.
7. What are the classifications of manholes?
a) Shallow man holes
b) Normal man holes
c) Deep man holes
8. What is testing of sewer pipes?
The sewer after being laid and jointed, are tested for water tight joint (leakage) and also for correct straight alignment.
9. Write two types of pumps?
A) Centrifugal pump
B) Reciprocating pump.
10. Mention the advantages of air pressure pumps?
(1) They are automatic complete units and requires least supervision
(2) They are useful in conditions, where there are channels of small capacity
(3) Centrifugal pumps getting clogged, if used. Such ejectors are not likely to be clogged anywhere.
(4) Compared to the construction of pumping stations, they are found to be economical at places, where smaller quantities of waste water are required to be lifted.
11.Write short notes on cast iron pipes.
C.I pipes are widely used for city water supply as they sufficiently resist to corrosion and durability is very high. It is available in 1.2m dia or more.
12.Describe about steel pipes.
The steel pipes are light and strong to without high internal pressure. They can be easily transported. But they cannot withstand external pressure. These pipes are not suitable for distribution system in water supply scheme.
13.Describe about G.I pipes.
These are manufactured by galvanizing iron pipe. The pipes are economical, light and easy to handle and transport. They can be easily cut and threaded.
14.Write short notes on cement concrete pipes.
The pre-cast cement concrete pipes are manufactured in rolling mills and then transported to the site as per requirement. The pipes may be made of plain concrete, reinforced cement concrete or pre-stressed cement concrete. The plain concrete pipes are used for carrying water at places there is no internal pressure.
15.Write short notes on R.C.C pipes.
The reinforced cement concrete pipes are manufactured by reinforcing with steel bars and casting the concrete in a frame work. These pipes can withstand high internal pressure.
16.Distinguish between spigot and socket joint
1. Sometimes this is called bell and spigot joint. This type of joint is mostly used for cast iron pipes.
2. For the construction of this joint the spigot or normal end of one pipe is slipped in socket or bell end of the other pipe until contact is made at the base of the bell.
3. After this yarn of hemp is wrapped around the spigot end of the pipe and is tightly filled in the joint by means of yarning iron up to 5 cm depth. The hemp is tightly packed to maintain regular annular space and for preventing jointing mutual from falling inside-the pipe.
4. After packing of hemp a gasket or joint runner is clamped in place round the joint so that it fits tightly against the outer edge of the bell.
5. Sometimes wet clay is used to make tight contact between the runner and the pipe so that hot lead may not run out of the joint space.
6. The molten lead is then poured into the V-shaped opening left in the top by the damped joint runner. The space between the hemp yarn and the clamp runner is filled with
17.Define expansion joint:
• This joint is used at such places where pipes expand or contract due to change in atmospheric temperature and thus checks the setting of thermal stresses in the pipes.
• The given Fig. 7.14 clearly illustrates an expansion joint. In this joint the socket end is flanged with cast iron follower ring, which can freely slide on the spigot end or plane end of other pipe.
• An elastic rubber gasket is tightly pressed between the annular space of socket and spigot by means of bolts as shown in. the figure.
• In the beginning while fixing the follower ring some space is left between the socket base and the spigot end for the free movement of the pipes under variation of temperatures.
• In this way when the pipe expands the socket end moves forward and when pipes contract, it moves backward in the space provided for it. The elastic rubber gasket in every position keeps the joint watertight
18.Explain collar joint for AC pipes
a) Concrete pipes and asbestos pipes are joined by this method.
b) The ends are placed together with a rubber gasket for water tightness.
c) Mortar of 1:4 is applied over the joint.
19. Write short notes on testing of pipes.
Keeping one of the valves closed water is filled without any air leak into the pipe. Close the inlet valve tightly. Pressure recording devices are fitted between these two valves. The inside pressure is increased to about 15N/mm2. The line is checked for 24 hours for leakages. This can be read from the fall in pressure in the pressure recording devices. If defects are found, it should be rectified.

20.Define sewage
The liquid waste from a community is termed as sewage. It mainly includes the discharges from latrines, urinals and stables. The human excreta is termed as night soil.
21.What is meant by sewerage?
The network of collecting and conveying sewage by water carriage system through the underground sewers is known as sewerage.
22.What is manhole?
The opening or hole through which a man can enter the sewer line or other closed structure for inspection and cleaning is termed as manhole.
23.Define sedimentation.
Sedimentation is the removal of suspended particles by gravitational settling. Sedimentation tanks are designed to reduce the velocity of flow of water so as to permit suspended solids to settle out of the water by gravity.
24. What do you mean by chlorination?
The application of chlorine to wastewater, generally for the purpose of disinfection , but frequently for accomplishing other biological or chemical results.


25.Name the various testing of sewer line.
i. Water Test
ii. Air Test
iii. Obstructions and straightness

PART – B
1. Explain briefly about pipe materials?
SEWER PIPE MATERIALS
QUALITIES:
In general the pipe should have the following qualities..
 durable..
 . against corrosion and abrasion.
 strength normally to bear external force.
 good hydraulic property.
 Smooth surface
 Easy to handle
 Light weight
 Less cost
 Joints can be easily made
The following materials are found suitable for sewer construction..
 Brick sewers
 Vitrified clay
 Cement concrete pipes
 Steel pipes
 Asbestos pipes
 Cast iron pipes
 Plastic pipes
 GRP Glassfibre reinforced Plastic Pipes


1.Brick sewers :
Brick and clay blocks are often used in the construction of sewers
Uses : lining in concrete pipes
Advantages : they are given below
• Locally available
• Cheap
• Smooth surface
• Available in various sections like circular,oval,basket handle type..
• High durability

Cement joints in brick sewers gives problem like corrosion . cement reacts with sewer gases and leads to corrosion . use of sewage resistant cement mortar or lime surshi gives long life..
DISADVANTAGES
• Less progress
• Labour cost is high
• Construction cost is high
2. VIRTIFIED CLAY :
Properties
• It is a clay product
• Widely used in sewer pipes
• Smooth surface
• Resistance to corrosion and erosion.
• Good performance.
• Used in small diameter sewage.
• Its maximum diameter is 60 cm.
• Difficult to handle
• Low strength


MANUFACTURE PROCESS : it is specially processed and moulded to the shape of the pipe as per the required length. The pipe has been extracted the press is stoped and pipe is cut off . the pipe is turned with bell end up and it is carried to the dying room and remain for 2 days on temperature and humidity.

Temperature is maintained to about 1100 *c to 1200*c over a period of 10 days. At the last stage glazing is done by throwing sodium chloride and glaze on the surface is done by adding NaCl with melted silica. As a result smooth surface is obtained. Improper verification causes cracks.


3. cement concrete pipes :

PROPERTIES :
 These pipes are strong , smooth and light weight
 Comparable cost
 Not durable for carrying domestic and industrial sewage
 It is subjected to freezing , wetting,drying and corrosive gases it can be prevented by concrete with good quality, good cement, low water cement ratio and densely packed..
 The main disadvantage is corrosion it can be prevented by following precautions listed below.
 Elimination of wastes containing sulphide
 Reduction of sulphates in sewage
 Aeration
 Chlorination
 Removal of salt and lime
 Reduction of turbulence
 Dosage with salts of copper zinc
 Running sewer fully
 Use of protective coating.

4. STEEL PIPES :
Steel pipes are used where lightness, imperviousness, and resistance to bursting pressure.
The main advantage is its flexibility. So it can resist shock movements and external pressure
Steel pipes for sewers are available in riveted,welded and corrugated sections..

5. ASBESTOS CEMENT PIPES :
• They are manufactured from a mixture of cement and asbestos fibre.
• They are light weighted, smooth and durable
• They are moderately good internal pressure
• They can be easily cut, fitted . drilled and joined
• They are brittle
• They are used in rain water pipes in house fittings
6. CAST IRON PIPES :
• IT has some extra strength of the sewer is required.
• The strength may be against internal pressure and external load
• So it is laid under railway and highway embankment
• They are costly and heavy.
ADVANTAGES :
 Smooth
 durable
 strong

7,PLASTIC PIPES
• they are durable
• strong against internal pressure
• easy to handle
• flexible

8. GLASSFIBRE REINFORCED PLASTIC PIPES G.R.P
• it is made of polyster resin, glass fibre and silica sand as filters
• The sand is used as filter it increases the wall thickness increases rigidity
• This pipes are costlier than any other pipes.
ADVANTAGES
 Light weight
 Corrosion resistance
 Easy to handle
 Smooth surface so hydraulically very effective
 Quick installation
 Low modulus of elasticity
 Repairing techniques are quicker.
 Flexibility



2. Explain sewerage system?
AIM :

 To provide a good sanitary environmental conditions in a city.
 To dispose human excreta to a safe place by a safe and protective means.
 To dispose all liquid wastes from a community to a proper place for preventing a favorable condition of mosquito breeding , fly developing or bacteria growing.
 To treat the sewage if required so as not to endanger the body of water or land to get polluted where it is finally disposed of.
 Proper disposal method should be adopted to protect sub soil water getting polluted.
SEWERAGE SYSTEMS
Nature of sewers provided for carrying different types of liquid wastes will indicate the sewerage system ..
There are three systems used in practice they are
 Combined systems
 Separate systems
 Partially separate systems




>.COMBINED SYSTEM :
In combined system one single set of sewers are laid for carrying liquid wastes from a community. Both sanitary sewage and storm water is allowed to enter sewerage system..

 SEPARATE SYSTEM
In separate system two separate system sets of sewers are laid . one set will carry sanitary sewage and the second set will carry storm water. As storm water is carried separately it is not foul in nature and naormally disposed of natural water cources without treatnment.


 PARTIALLY SEPARATE SYSTEM
This is also called as partially combined system . the sewers are designed as sanitary sewer but sufficient excess capacities are provided to carry. In initial washing from drainage area .
This system helps in simplifying the drainage of the houses it makes the sewer sizes smaller than combined system
The main disadvantage is delayed storm discharge and concerned area may remain flooded for certain time.
SEWAGE SYSTEMS
This is the system of sewers including all required sewage disposal.. a sewage system will consist mainly
1 collection work
2 treatnment works if any
3 disposal works

collection works are provided for collecting sewage from different points of cccurance and conveying sewage to desired parts..different types of sewers needed are house connections

 sewers from individual houses to public sewers , laterals,branches,sub mains, mains, trucks and outfall sewers
 laterals will be single sewer and it will not receive sewage from any other house connections..

 two or more laterals meeting together will form a branch sewer..


 two or more branches form a sub main
more than one sub mains meeting together will form main sewer and it is called trunk sewer..

 sewage treatnment covers any artificial process in which subjected to remove.

 Sewage disposal applies to the act of disposing the sewage by any method may be body of water or land.
 The last stretc of trunk sewer carrying sewage the disposal point is called outfall sewer.

3.Briefly explain the Activated Sludge treatment process with neat sketch.
4.Draw a neat sketch on different shapes of sewerage pipes.
The different shapes of sewers are
a) Circular sections
b) Non-circular sections.
(i) Egg shaped or ovoid section
(ii) Semi elliptical section
(iii) Rectangular section
(iv) Basket handle section
(v) Horse shoe section
(vi) Parabolic section
(vii) U shaped section

a) Circular sections:

Circular shape of sewer is selected for the following reasons:

(i) This gives least diameter
(ii) It has maximum hydraulic mean depth
(iii) It prevents possibility of deposit anywhere being of circular curvature
(iv) It is very economical
(v) The discharge is more or less constant in separate system
(vi) It has sufficient self cleaning velocity
(vii) The inner surface is smooth hence the flow of sewage is uniform and there is no chance of deposition of suspended particles.
(viii) The circular sewers are easy too construct.
b) Noncircular sections:
Non circular sewers are adopted for the following reasons:
(i) They can be constructed in such a convenient size and shape so that a man can enter the sewer for cleaning, repairing etc.
(ii) The process of construction is easy
(iii) The structural strength is more.
(iv) The cost of construction is low.
Types of Noncircular sections:
(i) Egg shaped or ovoid section
The egg shaped section sewers may be of two types normal egg shaped and inverted egg shaped. Both sections are suitable for carrying D.W.F and combined sewage.
(ii) Rectangular section
This type of sewer can be easily constructed. These are suitable for large sewers to carry heavy discharge of sewage. The maintenance works are easy in this section.
(iii) Basket handle section
In this sewer, the outer surface is circular. The inner surface is divided into portions. The upper portion resembles a basket-handle and the lower portion is like a channel.
During dry season, the sewage flows through the lower portion and during monsoon the combined sewage flows through the full section.

(iv) Horse shoe section
This type of sewer is constructed for carrying heavy discharge. This is like a tunnel and resembles a horse-shoe. The size is so large that the maintenance works within the sewer.
(v) Parabolic section
The upper surface of the sewer is in the shape of a parabola and the invert is in the shape of an ellipse. The type of sewer is suitable for carrying small discharge.

5.Explain about laying and testing of sewerage pipe?
Laying of the sewer or sewerage pipe:
Laser Method of Laying Pipe
Another useful device for controlling pipeline excavations and laying pipe is the laser. So many applications are being found for the laser that it may eventually be the only tool needed for the layout and control of construction projects. It can be quickly, accurately, and economically used for purposes such as distance measurement, alignment for tunnel borings, setting of pipes with desired grades, and setting of line and grade for many types of construction.
The laser is an intense light beam that can be concentrated into a narrow ray, containing only one color (red) or wavelength of light. The resulting beam can be projected for short or long distances and is clearly visible as an illuminated spot on a target. It is not disturbed by wind or rain, but it will not penetrate fog. A laser can be set up on a bracket or even attached to a transit telescope. The beam is aligned in the proper direction at the desired grade and can be left relatively unattended.
Today, instead of using batter boards and strings, lasers can be used to control the alignment for excavating trench and setting a pipe. The laser can be set so that it shines on the boom of a backhoe so that the equipment operator can clearly see the illuminated spot. By its position, the operator can closely control the depth of digging. For laying the pipe, the laser is set in the proper direction at the desired distance above the pipe invert. With the aid of the L-shaped pole or templet, as shown in figure 10-21, the workmen can control the invert elevation. It may also be possible to direct the laser beam from the inside of manholes through the pipes being laid and to control the grade without any interference from the back ill operations. This can be done even if the pipes are too small for human access.
Underground Duct System Layout
The stakeout for an underground power line is similar to that for a sewer. For the ducts, cuts are

Figure 10-21.—Pipe laying with a laser.
measured to the elevation prescribed for the bottom of the duct, plus the thickness of the concrete encasement, if any. In an underground power system, the bottom of the manhole is usually about 2 feet below the bottoms of the incoming and outgoing ducts. Power and communications manholes are often combined; figure 10-22 shows plan and section views of a combination power and communications manhole. Conduit and cable connections to buildings, street-lighting systems, traffic light systems, and the like, are low-voltage secondary lines. Duct connections from main-line manholes run to small-subsurface openings called hand holes on the secondary line. The hand hole contains connections for takeoff to the consumer outlet. Figure 10-23 shows plan and section views of a hand hole.
Construction Sheets
Several construction situations have been mentioned in which line and grade for construction are obtained from a line (or perhaps from two lines) of off set hubs. A guard stake adjacent to one of these hubs usually gives the station and elevation of the hub, grade for the structure at this station, and the vertical distance between the top of the hub and grade, marked C or F.


Figure 10-22.—Combination power and communication manhole.
This information is often recorded on a construction sheet (familiarly known as a cut sheet) like the one shown in figure 10-24. One advantage of the use of cut sheets that the information applying to every hub is preserved in the event that guard stakes are accidentally

Figure 10-23.— Handhole.


6. Explain briefly about pumps and their advantages.


7.Design of sanitary and storm sewerage
Sanitary Sewer Design
These criteria have been collected from various resources and they are meeting accepted standards for sanitary sewer design in the City of Oakland. The Design Engineer shall use these criteria to estimate design flows as accurate as possible and shall be submitted to the City of Oakland for approval.
These criteria shall be considered to determine the projected flow:
• Tributary areas
• Estimate of population
• Land use
• Per capita flow for
o Residential flow
o Commercial flow
o Industrial flow
• Major point source discharge
• Ground water
• Infiltration and Inflow
Tributary area of a sewer shall include all areas that will contribute flow to the sewer system. It shall include flows from the developed area to the point of connection to main line.
Estimate of population shall be for the proposed development and shall be as accurate as possible. Land use contributes and defines the densities of population and the type of users contributing to the flow within the tributary areas. To verify that the projection is reasonable, zoning maps and field review may be used.
Where uses are planned for an area, the average flow rates shown in Table 1 shall be used to estimate flows.
Industrial flow may vary significantly per industry type, size and the way wastewater is being discharged. The Design Engineer shall determine the magnitude of the industries’ wastewater contribution in the area.
Major discharges from future point sources shall be incorporated in the design flow. Future development of major establishments should be ascertained from the available information, including the City’s General Plan, Zoning and Land Use maps.
Infiltration/Inflow shall be added to the design total flow.


Design Flow Calculation
The design sewage flow rate (Q) is computed by the following:
Q = [gADM]peak + [IA]infiltration
Where: Q = total flow
A = tributary area, in acres*
D = future population density, persons per acre*
g = average flow rate*
M = coefficient for Peak Flow

I = infiltration rate = 1000 gallons / day / acre
. Pipe Design
• Sewer pipes shall be designed for minimum velocity of 2 feet per second.
• The minimum pipe size for sanitary sewer is 8” inside diameter.
• If a flatter slope is proposed, the pipe shall be designed to prevent settlement of solids in the pipe.
• The design flow velocity shall not exceed 10 feet per second unless warranted by special conditions.
• A minimum of 10 feet wide easement shall be required for sewer within private properties
Storm sewerage:
The urban storm water infrastructure can be viewed as consisting of a minor system and a major system. The minor system is designed to handle frequently occurring events with return periods typically on the order of 2 to 10 years. Physically, the minor system consists of roadway gutters, inlets, storm sewer pipes, and other appurtenances.

The major system consists of the pathways taken by flows in excess of the capacity of the minor system. It can be thought of as inundated roadways, swales and depressions, and natural and man-made open channels. A major system always exists, even when a minor system does not. Unfortunately, however, major systems are often neglected and do not receive the attention that they warrant, especially in light of the high probability of operational failure of the minor system.
The overall process of storm drainage planning, design, and construction can be broken down into a number of phases. These phases are:
1. Master planning
2. Concept and preliminary design development
3. Detailed design
4. Preparation of construction drawings, specifications, and contract documents
Each of these phases is described more fully below.
Master Planning
Master planning, often conducted for an entire urban area by a drainage system authority or review agency, provides a holistic view of the urban drainage system and how its various components interact. The need for master planning is particularly acute where an urbanized area spans a number of different political jurisdictions, each having its own objectives and design criteria. In such instances, master planning can help ensure that systems that cross jurisdictional boundaries are consistent with one another. Even if only one political jurisdiction is involved, master planning provides very useful guidance for constructing new systems that are consistent not only with one another, but also with facilities that already exist.
The issues that should be addressed by a master plan
a minimum, delineations of major urban drainage ways (whose floodplains might be mapped for flood insurance purposes) and approximate limits and locations of storm sewers in the contributing drainage basin(s). The master plan should also make a clear distinction between the minor and major drainage systems and should take whatever steps are politically and legally possible to ensure that the major system is functional and provides a reasonable degree of protection from severe storm events.
Technically, a master plan should contain enough detail to be an effective guide to the ultimate construction and/or rehabilitation of storm drainage facilities in the area covered by the plan. Hydrologic analyses should be of sufficient detail to provide reasonable estimates of required system conveyance capacities and should address estimates of expected future flows in developing drainage basins. Zoning master plans, where available, are invaluable for providing estimates of ultimate land uses in a drainage basin.
The master plan report and other documents should clearly state the design storm recurrence intervals for which planned drainage facilities are to be designed, and should be referred to frequently as individual components of the overall system are designed and constructed. A listing of typical design storm recurrence intervals, as recommended by the American Society of Civil Engineers (ASCE, 1992), is presented in Table 10.1.
Table 10.1 Typical return periods for design of storm water drainage systems (ASCE, 1992)
Land Use Return Period (yr)
Minor drainage systems:

Residential 2-5
High-value generation commercial 2-10
Airports (terminals, roads, aprons) 2-10
High-value downtown business 5-10
Major drainage system elements Up o 100

In areas where existing storm drainage facilities require rehabilitation and/or retrofitting, and especially in cases where additional right-of-way acquisitions may be required, the master plan should identify such needs and should provide estimates of the costs associated with the upgrades.
Concept and Preliminary Design Development
As new subdivision developments occur in an area, or as drainage improvement projects take place, developments of preliminary designs and concept plans should precede detailed final design activities. Preliminary designs should be consistent with the broad system outlines established during the master planning phase, but should provide additional detail on locations of individual drainage structures and features. In the case of a new subdivision, for example, the preliminary design can be indicated on a preliminary plat showing the proposed street and parcel layout of the development. This preliminary design provides jurisdictional authorities with an opportunity to review the consistency of the proposed facilities with the broader-scale master plan and ensure that both minor and major drainage system considerations have been dealt with.
Activities associated with preliminary design entail more detailed hydrologic analyses than those conducted for master planning purposes and should explicitly account for how the proposed facilities fit into larger-scale regional plans. Design alternatives should receive detailed evaluation in this phase, as should methods for dealing with upstream flows and discharges to downstream areas.
At a minimum, a preliminary design drawing and report should consist of topographic mapping on which streets, land parcels, and proposed storm drainage facilities have been superimposed. The storm drainage layout should indicate pipe, manhole, and inlet locations, as well as locations of other features such as detention and/or retention ponds. Drainage basins contributing to each inlet should be shown and should be referenced to accompanying hydrologic estimates of design flows in a report. Finally, the preliminary design report should explicitly address the major drainage system, including showing the general pathways and directions of major system flow on the design drawing.
Detailed Design
Following the approval of the preliminary design by the appropriate jurisdictional authority or authorities, the engineer can proceed with the detailed design. As the name implies, this phase involves detailed engineering analyses that will serve as the basis for the design as described by the construction plans and specifications..

Detailed hydrologic and hydraulic analyses must be performed at this stage in order to finalize design discharges and determine the dimensions of hydraulic structures such as pipes, inlets, ponds, and energy dissipators. Structural analyses are necessary to determine required pipe strength classes or wall thicknesses, and may also be required for other project-specific special structures. Geotechnical analyses are necessary to locate shallow bedrock that could affect construction costs; to determine groundwater elevations that could affect trenching, buoyancy forces on submerged pipes and structures, and pipe infiltration; and to determine pipe bedding requirements.
The maintenance of complete and well-organized files that document each activity and decision made during the detailed design phase is essential. Should unforeseen circumstances occur during construction, or should litigation arise after construction of the system has been completed, these files will provide a record of the adequacy of the design and its consistency with accepted engineering practice.
8.Explain the unit operations with flow chart of treatment of sewage.

9.Describe about the secondary treatment of sewage.
10. Sketch and explain.
INTAKES STRUCTURES
Collection and Conveyance:
• The main function of the intakes works is to collect the water front the surface source (within limitations of the water levels) and then discharge water so collected, by means of pumps or directly to the treatment water.
• Intakes are structures which essentially consist of opening, grating or strainer through which the raw water from river, canal, or reservoir enters and is carried to a sump well by means of conduits.
• Water from the sump well is pumped through the rising mains to the treatment plant.
TYPES OF INTAKES:
Intakes are used to collect water for water works from various sources. The sources may be lakes, rivers, reservoirs or canals. The intake work for each type of source is designed separately according to its requirements situations. Depending on the source of water the intake works are classified as follows
(a) Lake Intake (h) Reservoir Intake (c) River Intake (d) Canal Intake
-

i) Direct intake from river

The masonry towers generally circular in cross-section with 5 to 6 meters in diameter constructed on the bank of the river but fulfilling to the conditions for selection of site. The intake tower itself serves as a sump well at the lower part and upper half acts as engine house for installing pumping equipments and also as control room.
For letting water into the sump well, a number of openings or ports are provided with penstocks and valves at different levels which are placed at the downstream side of the structure to avoid excessive current action and slit transportation to the well. Coarse screens are used at the free end of the penstocks. The inlets are operated as per requirement of water quantity and also with the condition of water level in the source. Water can be tapped little below the surface is found comparatively better in quality.
When the river drives up leaving a gap between the water course and the intake, then suitable approach channel is excavated. The velocity of the flow through the channel should not be very high, otherwise much of silt etc.will be carried.
In case of very big water supply scheme instead of circular, square or rectangular type intake cribs are constructed. Again for every small water supply scheme the tower is avoided and only the pipe is kept in the water with suitable protection. The pipe intake is consist of a simple horizontal pipe with bellmounth end and attached with a coarse strainer. The pipe is kept in place by wooden crib and heaving rocks and boulders. This is also known as piled crib intake and particularly suitable where the water level is more or less static.

ii) Intake from reservoir
The intake is a masonry or concrete structure similar to river intake and constructed in deep water near the upstream toe of the dam. The intake is provided with inlets ports at different designed levels. The water of impounding reservoirs is likely to vary in quality at different levels, making it advisable to take water from about a meter below the top surface. So the inlet ports at different level may be operated from the gate house with fluctuation of water levels.
Access to the intake tower for operation of gates, pumps and other purposes is made by means of a foot bridge. The water thus collected in the sump well is conveyed through the pipe across the dam structure to the water works system. The velocity of water should not be less than 0.75m/s. to avoid any siltation. The out-let pipe should be well protected with suitable concrete encasing, boulder placing ect.
In case of masonry dam, quite often the intake well is constructed in the dam structure itself. The main advantage of this type of arrangement is to avoid the cost of construction of separate intake crib, Foot Bridge and reducing the length of out-let pipe.
The ports in both the above types are protected by means of strong screens which also help in excluding the entrance of floating matters into the sump well. The valves can be operated from the gate house. A ladder is provided from the gate house to the sump well to facilitate inspection and maintenance.





UNIT – V
PART – A
1. Define plumbing.
Plumbing in a general term which indicates the practice, material and fixtures used in the installation or maintenance of all pipings, fixtures, appliances and other appurtenances used in connection with other public or private water supply systems as well as sanitary or drainage systems, within or adjacent to any building or its connection with any point of public disposal.
2. What is “Plumbing water supply”?
Plumbing water supply system is consisted of supply distribution pipes (called service pipes), connections, domestic storage tanks, flushing storage tanks etc in a building.
3. What is plumbing sanitary or drainage system?
Plumbing sanitary or drainage system consists of water closets, urinals and other such appliances like traps, solid waste and sewers, flushing cisterns etc in a building.
4. Name the components of water connection system.
a) Ferrule
b) Goose neck
c) Service pipe
d) Stop cock
e) Water meter.
5. Write the importance of underground storage tanks.

Underground storage tanks are necessarily required to collect water from municipal supply lines, if the water pressure in the main is insufficient to reach the overhead tank. The water collected in the underground tank is then pumped into the overhead tank. The installation of pump on the municipal mains is always prohibited by the municipal authorities, as it reduces the water pressure in the adjoining houses or buildings.
6. Give examples for metal tanks used for water storage purpose.
Metal tanks fabricated from mild steel or galvanized iron sheets have been used in the houses over the years, as they can be easily fabricated and are light durable and easy to install are the examples of metal tanks.
7. What are the advantages of mild steel (M.S) metal tanks?
a) easily fabricated
b) light
c) durable and
d) easy to install.
8. Explain HDPE .
HDPE is High Density Polyethylene Pipes are used in special situation. These pipes are not brittle like other pipes and hence a hard fall at the time of loading, unloading, handling etc. HDPE pipes upto 630mm dia can be joined with detachable joints and can be detached at the time of shifting the pipe line from one place to another. HDPE pipes can be joined also by welding.
9. Write the advantage of automatic pumping system.
a) It eliminates the need for overhead tanks and is ideal for existing buildings when new overhead tank. Cannot be constructed and also for new buildings and when the tanks placed on roof cannot generate enough pressure at upper floors.
b) The system is able to supply water at much higher pressure than it is possible from local overhead tanks.
c) System is more reliable in such situations in hot climatic regions; the water supplied from overhead tanks becomes too warm, while in cold regions, it may freeze.
10. What is “bib cock”?
Bib cock is a type of valve provided at the end of service pipes for with drawing water at the consumer houses. By rotating the handle of the bib cock, the orifice opening, through which the water passes, can be increased or decreased, thereby controlling the outflow through the spout.
11. What is the use of ventilation in the buildings?
The ventilation is usually achieved by providing a fresh air inlet connected to the lower-most manhole or inspection chamber. Fresh air from the atmosphere will enter through this inlet into the manhole, and finally goes out at top through the vent pipe. The air along with foul gases will finally escape out from the cowl provided at the top. A flap valve is provided at the inlet of fresh air into the inspection chamber, to avoid the escape of foul gases in the street or courtyard.
12. What are called sanitary fittings?
Plumbing is the practice, materials and fixtures used in the installation or maintenance of all pipes in connection with both water supply and sanitary systems within or adjucent to any building. The entire system of piping, fittings and the appurtenances are known as plumbing system. Sanitary plumbing system includes the pipes, fittings are the appliances used in a house plumbing system, to receive the human excreta and sullage wastes of the house.
13. List out the various sanitary fittings.
Sanitary fittings are:
1. Water closets (WC),
2. Urinals,
3. Flushing cistern for water closets
4. Bath tubs,
5. Washing basins,
6. Kitchen sinks.
14. Write any five principles of sanitary plumbing system
a) The house sewer should be connected to the street sewer, keeping the outfall level of the house sewer sufficiently higher than the water level of the public sewer to avoid backflow.
b) The plumbing system should contain enough number of traps, to avoid evolution of foul smells and the efficient functioning.
c) Laterals should be laid at sufficient slope so as to develop self-cleansing velocities.
d) The joints of the pipes should be made watertight.
e) The layout of the system should be such as to permit easy cleaning in case of blockage.
15. Define house drain sizing.
The size of pipe to be used in a house drain is determined by the number of units drained by it. Proper diameters are: for 2 units, 1 1/2"; for 9 units, 2"; for 25 units, 2 1/2".
The size of any stack, house drain, or sewer must be, however, at least the size of the argest branch connected to it. The minimum size of a house drain receiving the discharge from a water closet should be 4" in diameter, and this pipe should continue full size to the vertical stacks receiving the discharge of water closets. Even without any water closets discharging into a system, the drainage system should have at least one 3" diameter stack extended full size through the roof.
16. How will you size the vent pipe?
The proper size for the vent stack is determined by the total fixture units of the soil or waste stack it serves. A branch vent is sized by the number of units connected to it and the length of the pipe itself. No vent pipe should be less than 1 1/4" in diameter, nor should a vent stack's diameter be less than half the diameter of the soil stack it serves. This means that with a 4" soil stack, vents cannot be less than 2" pipe. In determining the length of vent piping, regard length of stack and branches as being continuous.
17. Write short note on smoke test in pipes.
The smoke test requires the use of a smoke machine. All lower openings in the system are sealed, but the roof openings are left uncapped. Smoke is then pumped into the system until a considerable volume of it is seen issuing from the roof openings. Then they are capped. The machine continues to force smoke into the piping until a pressure equivalent to a rise of one inch in a water column gauge is reached. At this point, check all connections for signs of smoke. The principal objection to the smoke test is the possible damage it might do to interiors in the case of a line break.
Make either the peppermint or the smoke test on old piping. The peppermint test is preferred because it can be detected in places, such as underground piping, where smoke cannot. As these tests are usually made in the presence of a local building or public health inspector, you should pre-test all connections before calling him in. You should also remember that excessive pressure in either the smoke or the air test will blow out your trap seals, defeating the entire purpose of the test. To avoid this, take care to use only recommended pressures.
18. What are the advantages of aeration system in water treatment system?
• Plants are easy to operate, as the management of operation is for a maximum of two or three hours per day.
• Extended aeration processes are often better at handling organic loading and flow fluctuations, as there is a greater detention time for the nutrients to be assimilated by microbes.
• Systems are odor free, can be installed in most locations, have a relatively small footprint, and can be landscaped to match the surrounding area.
• Extended aeration systems have a relatively low sludge yield due to long sludge ages, can be designed to provide nitrification, and do not require a primary clarifier. .
19. What are the disadvantages of aeration system in water treatment system?
• Extended aeration plants do not achieve denitrification or phosphorus removal without additional unit processes.
• Flexibility is limited to adapt to changing effluent requirements resulting from regulatory changes.

20. Explain FRP.
FRP is Fibre Glass Reinforced Plastic or composite of glass fibre, polyester resin and fillers. These pipes possess better strength, durability, high tensile strength and are highly corrosion resistant.

21. List the different systems of plumbing.
The different systems of plumbing are as follows.
1. Two pipe system
2. One pipe system
3. Single stack system
4. Partially ventilated single stack system.
22. What are the various kinds of vent piping?
a) Main vent
b) Branch vent:
c) Fixture vent:
d) Individual trap vent:
e) Dual connection
23. What is meant by individual trap vent?
A trap may be supplied with air near its crown by the installation of a vent at the trap itself. In this way, the possibility of a vacuum forming at this point is eliminated.
24. Write a note on branch vent in drainage piping.
Connected to the main vent, this pipe serves two or more fixture vents. It and the fixture vent should be run to a height above the overflow level of the fixture being served. This prevents sewage from draining through the vent line if the fixture waste branch gets clogged.
When properly connected, vent lines will remain free and any stoppages in the drain piping will be indicated by the backing up of waste into the fixture.
25. Write about the Single stack system
This system is having a single pipe for soil, waste and vent without any separate ventilation pipe. It uses only one pipe, which carries night soil as well as sullage and the same pipe is extended up to 2 m above roof level with a cowl to act as vent pipe for removal of gases.