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1. 'PARSHVA CLASSES', Khatri Pole, Behind Jubilee Baug, Baroda-1, Ph. 2432603
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 INTRODUCTION :
 Public health engineering is a combination of branches “water supply
engineering” and “Sanitary engineering”. It deals with general health and well
being of people.
 Water supply engineering : Water supply engineering takes care of adequate
quantity and good quality of water to be distributed to the users for domestic
and industrial purpose. It is concerned with the purification of water and its
distribution network.
 Sanitary engineering : It is the branch of public health engineering which
deals with the prevention and maintenance of health of the individual and
the community, by preventing communicable diseases.
 IMPORTANCE AND NECESSITY OF WATER SUPPLY SCHEME :
Next to air, the other important requirement for human life to exist is water.
It is the Nature’s free gift to the human race. Everyone of us know how
important and precious the water is. Whenever there is no water in our taps,
we becomes helpless. No life can exist without water.
 Various uses of water are :
(i) Drinking (ii) Cooking
(iii) Bathing and washing clothes (iv) Sprinkling in garden
(v) Agriculture use (vi) Road washing
(vii) Fire fighting (viii) Hydropower generation
(ix) Construction (x) Swimming Pools, fountains
(xi) Industrial use, etc.
A successful implementation of a water supply scheme gives the
following benefits :
(1) Availability of good quality water.
(2) Availability of sufficient quantity of water.
(3) Decrease in water borne diseases like colera, typhoid, dysentery, etc.
(4) The sanitation of the area is considerably improved by the adequate water supply.
(5) Water is used economically and, losses and wastage are reduced.
(6) Growth is industries due to availability of sufficient quantity of water.
(7) Increase in opportunities of employment to the local people.
(8) The growth of new industries for various pipe appurtenances such as valves,
bib cocks, etc. takes place in the locality granting employment opportunities.
UNIT -1INTRODUCTION
WATER SUPPLY & SANITARY ENGINEERING
 (O) (0265)2432603
Mobile : 9825117931
9825977394
9825017931
FATEHGUNJ BRANCH :
SB-17, EMPEROR COMPLEX,
BESIDE " GOODIES "
FATEHGUNJ,
VADODARA.
SHREE PARSHVAJAY AMBE PRAKASH K. BHAVSAR'S
PARSHVA CLASSES
[ FOR ENGINEERING ]
DEGREE & DIPLOMA MSU & GTU
A NEW NAME OF 'GURU CLASSES'
HEAD OFFICE :
PANKIL CHAMBERS,
KHATRI POLE,
B/H. JUBILEE BAUG,
RAOPURA, VADODARA.
WAGHODIA BRANCH :
3-GAJANAND SOC.,
ABOVE INDIAN OVERSEAS
BANK, UMACHAR RASTA,
WAGHODIAROAD,
VADODARA.

2. 'PARSHVA CLASSES', Khatri Pole, Behind Jubilee Baug, Baroda-1, Ph. 2432603
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 SOURCES OF WATER :
The locations form where water can be available are called sources of water.
The distribution of water on the earth is as follows :
Seas and oceans _ _ _ _ _ 97 %
Ground water _ _ _ _ _ 02 %
At poles as frozen ice _ _ _ _ _ 0.75 %
Rivers and lakes _ _ _ _ _ 0.25 %
Total = 100 %
Surface area occupied by land = 29 %
Surface area of earth occupied by water = 71 %
 Sources of water : There are two types of water sources available on earth.
(1) Surface water sources (2) Ground water sources
SOURCES OF WATER

Surface water sources Ground water sources
 
- Lakes - Infiltration well
- Ponds - Infiltration galley
- Streams - Springs
- Rivers - Wells - Open well - Artesian well
- Storage reservoir - Tube well - French well
[a] Surface water sources :
(1) Lakes : These are natural large sized depressions formed within the surface
of earth, and filled with rainwater. The quality of water in a lake is generally
good and does not need much purification. Larger and older lakes provide
comparatively purer water than the smaller and newer lakes. In lakes, growth
of algae and some water vegetables are generally common.
(2) Ponds : Ponds are also natural inland depressions filled with rainwater but
are small and shallow water bodies compared to lake.
(3) Streams : Streams are formed by the small amount of water running down
the hills joining to rivers or lakes. The quantity of water available in them is
very small and sometimes they may go dry.
(4) Rivers : When number of streams combine together, a river is formed. Rivers
are the most important sources of water for public water supply schemes.
The quality of water available from river is quite variable as in monsoon
season, water is highly turbid compared to non-monsoon season.
(5) Storage reservoirs : Storage reservoirs are formed by constructing dams
across the river valley. Huge quality of water is stored in the reservoir formed
upstream of the dam. Various uses of storage reservoirs are :
- Public water supply - Irrigation
- Power generation - Flood control, etc.
[b] Ground water sources :
(1) Infiltration well : For tapping water from sandy river beds the infiltration
wells are sunk is series in sandy river beds. These are constructed of brick
masonry with open joints. The water percolates through these joints and
gets collected in the wells. The top of the wells are covered with R.C.C. slab
having manhole for inspection.

3. 'PARSHVA CLASSES', Khatri Pole, Behind Jubilee Baug, Baroda-1, Ph. 2432603
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The water from the infiltration wells gets collected in a jack well. Then the
water from the jack well is pumped out and stored in a storage reservoir.
The quantity of water so obtained is good and it requires no treatment. The
quantity of water from this source is suitable for small water supply schemes.
(2) Infiltration gallery : For tapping water
from sandy river beds sometimes
horizontal tunnels are constructed in the
river bed at shallow depths (3 to 5 cm)
along the banks of the river. The walls of
the tunnel are constructed for brick
masonry and its top is converd with R.C.C.
slab having manholes at some interval.
The perforated pipes are connected to the
tunnel through which the water gets
collected inside the tunnels. This tunnel is
known as infiltration gallery.
 SELECTION OF SOURCE OF WATER SUPPLY :
The following points should be considered while selecting the site for the
sources of water for a water supply scheme :
(1) Location (2) Elevation of intake point
(3) Quantity of available water (4) Quality of available water
(5) Topography of the intervening area
(1) Location : The source of water must be situated as near as possible to the
town or city to minimize the cost of conveyance.
(2) Elevation of intake point : The reduced level (R.L.) of the intake point
should be higher than that of the city or town to be supplied with water, so
as to make the gravity flow possible. When the water is available at lower
levels than the average city level, pumping has to be resorted, which involves
huge operational cost and frequent possible breakdown.
(3) Quantity of available water : The quantity of water available at the source
must be sufficient to meet the various water demands during the entire
design period of the scheme.
(4) Quality of available water : The water available at the source must not be
toxic, poisonous or in any other way injurious to health. The impurities present
in the water should be as less as possible, and should be such as to be
removed easily and economically by normal treatment methods.
Bad quality water requires excessive treatment and increases the cost.

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(5) Topography of the intervening area : The area or land between the source
and the city should not be highly uneven. In other words, it should not contain
deep valleys or high mountains and ridges. In such uneven topography the
cost of trestles for carrying pipes in valleys and that of constructing tunels in
mountains, shall be enormous.
(6) Cost : While selecting a source of water for a water supply scheme, it is
necessary to estimate the cost of the project.
The cost of the project depends on :
(i) System of supply : If water is to be supplied by gravity method the cost
will be low, but in case of pumping the cost will be higher.
(ii) Difference in level of source and the city : If the source of water is at
higher elevation as compared to the city, water can be supplied by gravity
and the cost will be less. If the source of water is at lower elevation as
compared to the city, water has to be supplied by pumping. In this case the
cost of pumping and operating will be high.
(iii) Distance of city from the source of water : If the distance of the city
from the source of water is large, the cost of pipeline, valves, fittings, etc.
will increase.
(iv) Topography : In a plain topography the cost of construction of the
water supply scheme will be less. But, in case of uneven topography this
cost will be higher.
(v) Availability of construction material : If suitable construction materials
are available in the near by area, the cost of construction of the water
supply scheme is reduced.
 CRITERIA CONSIDERED FOR WATER SUPPLY SCHEME :
The water supply schemes are prepared by the combination of field
observations and office work.
The following points should be considered while planning a water supply scheme :
(1) Financial aspect (2) Population
(3) Quality of water (4) Rate of consumption
(5) Sources of water supply (6) Sanitary survey of area
(1) Financial aspect : In the initial stage of water supply scheme the data
regarding the availability of fund for the scheme should be obtained. The
scheme should than be planned in relation to the fund available. Attempt
should be made to make the scheme as economical as possible.
(2) Population : Water supply projects are designed to serve over a specified
period of time after completion of the project. This time period is called
design period. Water works are generally designed for 330 years.
So, the probable population of the town or city should be ascertained for the
future decades by suitable method.
(3) Quality of water : The quality of available water decides the line of
treatment of water. The impurities present in water should be as less as
possible, and should be such as to be removed easily and economically
by normal treatment methods.
Bad quality water requires excessive treatment and increases the cost.
(4) Rate of consumption : The demand of water depends on various uses such
as domestic, public, industrial, etc. The rate of consumption of water per

5. 'PARSHVA CLASSES', Khatri Pole, Behind Jubilee Baug, Baroda-1, Ph. 2432603
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capita should be decided by carefully considering all these possible uses. This
rate when multiplied by the population, gives the total quantity of water
required for the water supply scheme.
(5) Sources of water supply : The cost of the water supply scheme depends on
the selection of the site for the source of water. So, the source of water should
be such that the cost of conveyance and water treatment may be reasonable.
(6) Sanitary survey of area : The sanitary survey of area surrounding the
available water sources helps in estimating the possible pollution or
contamination of water from such sources. The sanitary survey includes the
collection of information regarding possible sources of water pollution.
 DUTIES OF PUBLIC HEALTH ENGINEERS :
The following are the duties of public health engineers :
(1) The engineer should have perfect knowledge about planning, designing,
construction and maintenance of water works and sanitary works.
(2) He must be capable to operate the water works without fail and should
supply the safe potable water to the public at desired pressure.
(3) He should be able to detect the possible cause of contamination of water
sources and should take necessary measures to prevent such contamination.
(4) He should know the various water treatment methods.
(5) He should know the laboratory tests which may be required for the treatment works.
(6) He should be aware of the latest techniques and methods of water purification.
(7) He should have a knowledge of water distribution networks.
(8) He should take the water samples at certain time intervals to maintain the
quality of water.
(9) He design sewage and storm water drainage network for proper disposal of sewage.
(10)He do design, construction and operation of sewage treatment plants.