BUILDING SERVICESWATER SUPPLY AND SANITATION

Presented By-Ar. Roopa Chikkalgi

Building services/Building services engineering, play a central role in

contributing to the design of a building, not only in terms of overall strategies and

standards to be achieved, but also to make the buildings comfortable, functional,

efficient and safe.

Building services engineers/architects are responsible for the design, installation,

operation and monitoring of the mechanical, electrical and public health systems

required for the safe, comfortable and environmentally friendly operation of modern

buildings.

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Water supply is the provision of water usually via a system of pumps and

pipes.

Sanitation is the hygienic means of promoting health through prevention of

human contact with the hazards of wastes as well as the treatment and proper

disposal of sewage or wastewater.

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Terminologies in water supply and sanitationSewageWaterborne human(water-carried waste), domestic waste.

It is Liquid Waste or Waste Water produce as a result of water use.

SewerIt is the pipe or conduit for carrying sewage. It is generally closed and flow takes place under gravity

(Atmospheric Pressure).

SewerageIt is the system of pipes, chambers, manholes, etc. that conveys the sewage or storm water. Sewerage is the

system of collection of waste water and conveying it to a point of final disposal with or without treatment.

Sewerage ends at the entry to a sewage treatment plant or at the point of discharge into the environment.

Greywater• Greywater or Sullage is all wastewater generated in households or office buildings from streams

without fecal contamination, i.e. all streams except for the wastewater from toilets.

• Sources of greywater include, e.g. sinks, showers, baths, clothes washing machines or dish

washers. As greywater contains fewer pathogens than domestic wastewater, it is generally safer to

handle and easier to treat and reuse onsite for toilet flushing, landscape or crop irrigation, and

other non-potable uses.

Sources of waste water•Domestic

•Industrial

•Storm water4

Seepage

The slow escape of a liquid or gas through porous material or

small holes. A soak pit , also known as a soak away or leach pit, is

a covered, porous-walled chamber that allows water to slowly

soak into the ground.

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Terminologies in water supply and sanitation

Manhole

A manhole (alternatively utility hole, cable chamber, maintenance

hole, inspection chamber, access chamber, sewer hole, or

confined space) is the top opening to an underground utility vault

used to house an access point for making connections,

inspection, valve adjustments or performing maintenance on

underground and buried public utility and other services including

water, sewers, telephone, electricity, storm drains, district heating

and gas.

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Environmental health

• Environmental health is the branch of public health concerned with the aspects related to the

natural and built environment likely to affect human health.

• Environmental health also includes the provision of environmental services to households

and communities, such as water supply or air pollution control.

Providing essential environmental services to households and communities.

These can include:

1. Sanitation

2. Water supply

3. Traffic control

4. Hygiene promotion

5. Air pollution control

6. Storm water drainage

7. Solid waste management

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Introduction to Environment and Health Aspects

■ The environment in which we live greatly affects our

health.

• The natural and built environment in which we live,

the water we drink, the air we breathe or the houses

we occupy, greatly affect our health. for instance, if

our drinking water is polluted, we shall probably

suffer from bad health.

• A safe, reliable, affordable, and easily accessible

water supply is essential for good health. Yet, for

several decades, about a billion people in

developing countries have not had a safe and

sustainable water supply.

• The health aspect of environmental services, in

particular sanitation, water treatment and solid

waste management. Protecting human health can

also lead to improving the natural environment.

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History of water supply and sanitation

Prehistory

• Major human settlements could initially develop only where freshsurface water was plentiful, such as near rivers or natural springs.

• Throughout history people have devised systems to make gettingwater into their communities and households, and disposing (andlater also treating) wastewater more convenient.

• Early human habitations were often built next to water sources.rivers would often double as a crude form of natural sewagedisposal.

• During the Neolithic, humans dug the first permanent water wells,from where vessels could be filled and carried by hand. wells dugaround 6500 bc have been found in the jezreel valley.

• The size of human settlements was largely dependent on nearbyavailable water.

• Pit latrines and chamber pots were initially the only alternative toopen defecation.

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Indus Valley Civilization

• The Indus Valley Civilization in Asia shows early evidence of public

water supply and sanitation.

• The system the Indus developed and managed included a number of

advanced features. A typical example is the Indus city of Lothal (c.

2350 BCE).

• In Lothal all houses had their own private toilet which was connected

to a covered sewer network constructed of brickwork held together

with a gypsum-based mortar that emptied either into the surrounding

water bodies or alternatively into cesspits, the latter of which were

regularly emptied and cleaned.

• The urban areas of the Indus Valley civilization included public and

private baths.

• Sewage was disposed through underground drains built with precisely

laid bricks, and a sophisticated water management system with

numerous reservoirs was established. In the drainage systems, drains

from houses were connected to wider public drains.

• Devices such as shadoofs and sakias were used to lift water to ground

level.

• Ruins from the Indus Valley Civilization like Mohenjo-daro in Pakistan

and Dholavira in Gujarat in India had settlements with some of the

ancient world's most sophisticated sewage systems. They included

drainage channels, rain water harvesting, and street ducts. 9

Mesopotamia

• The Babylonians introduced the world to clay sewer pipes,

c4000 BC.

• The first sanitation systems were built in the prehistoric

Middle East, in the south-east of the modern country of

Iran.

Ancient Greek civilization• The ancient Greek civilization of Crete, known as the

Minoan civilization, was the first civilization to use

underground clay pipes for sanitation and water supply.

• Their capital, Knossos, had a well-organized water system

for bringing in clean water, taking out waste water and

storm sewage canals for overflow when there was heavy

rain.

• It was also one of the first uses of a flush toilet, dating

back to 18th century BC.

• The Minoan civilization had stone sewers that were

periodically flushed with clean water. In addition to

sophisticated water and sewer systems they devised

elaborate heating systems.

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Roman Empire

• In ancient Rome, Public latrines were built.

• The Roman Empire had indoor plumbing, meaning a system of aqueducts and pipes that terminated in

homes and at public wells and fountains for people to use.

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Waste Disposal Methods

TYPES OF COLLECTION SYSTEM

Depending upon the type of waste, two systems may be employed for its

collection, conveyance and its collection, conveyance and disposal :

(a)Conservancy system

(b)Water carriage system

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Conservancy system • This system is also called as dry system.

• This is out of date system but is prevailing in small towns and villages.

• Various types of refuse and storm water are collected conveyed and disposed of separately.

• Garbage is collected in dustbins placed along the roads from where it is conveyed by trucks ones or twice a

day to the point of disposal. all the non combustible portion of garbage such as sand dust clay etc are used

for filling the low level areas to reclaim land for the future development of the town.

• The combustible portion of the garbage is burnt. The decaying matters are dried and disposed of by burning

or the manufacture of manure.

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• Human excreta are collected separately in conservancy latrines.

• The liquid and semi liquid wastes are collected separately after removal of night soil it is taken outside the

town in trucks and buried in trenches. After 2-3 years the buried night soil is converted into excellent

manure.

• In conservancy system Sullage and storm water are carried separately in closed drains to the point of

disposal where they are allowed to mix with river water without treatment.

Types of Wastes in the Conservancy system

1. Night soil -Night soils or human excreta in latrines, privies or cesspools etc. is collected separately in

pans or pails and carried on heads of sweepers to a central carried on heads of sweepers to a central

place from where it is transported in bullock carts or motor vans to a place away from the town for its final

disposal. Normally, it is buried into ground, in trenches, to give excellent manure in one or two years.

2. Garbage- Garbage is collected separately, in dust bins and conveyed on hand carts or motor van once or

twice is a day. motor van once or twice is a day. It may consist of waste matter of both non-combustible as

well as combustible type. The two are therefore sorted out. Then it is dumped by suitable method

3. Sullage and storm water- Sullage and storm water are collected and conveyed separately in closed or

open gutters.

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DISADVANTAGES OF CONSERVANCY SYSTEM

1. Hygiene and sanitary aspect: The conservancy system is highly unhygienic and cause insanitary

unhygienic since the excreta starts decomposing within few hours of its production.

2. Transportation Aspect: Transportation of night soil takes place in open carts through streets and other

crowded localities. This is highly undesirable.

3. Labor Aspect- The working of the system depends entirely on the mercy of labor (sweepers). If they go

on strike even for (sweepers). If they go on strike even for one day for any reason whatsoever, the

lavatories can not be used because of foul smell. The whole locality will smell very badly.

4. Design Aspect- The lavatories are to be located outside the house and slightly away from the main

slightly away from the main building. The compact design is therefore not possible.

5. Condition of Drains - Insanitation may be there due to carriage of sullage through open drains laid in

the streets.

6. Risk of Epidemic Diseases.- Due to improper or careless disposal of night soil, there are more chances

of. outbreak of more chances of. outbreak of epidemic.

7. Cost Consideration- Though the system is quite cheap in the beginning, its maintenance and

establishment costs (i.e. recurring establishment costs (i.e. recurring expenditure) are very high.

8. Disposal land requirement-The system requires considerable land for the disposal of sewage.15

Water Carriage System■ With development and advancement of the cities urgent need was felt to replace conservancy

system with some more improved type of system in which human agency should not be used for the collection and conveyance of sewage .

■ After large number of experiments it was found that the water is the only cheapest substance which can be easily used for the collection and conveyance of sewage.

■ As in this system water is the main substance therefore it is called as WATER CARRIAGE SYSTEM.

■ Water Carriage System-In this system water is used as a medium to carry wastes to the point of final disposal. The quantity of water is so high (99.9%) that wastes becomes liquid which is carried by the sewers. The garbage is collected separately as in conservancy system.

■ In this system the excremental matter is mixed up in large quantity of water their ars taken out from the city through properly designed sewerage systems, where they are disposed of after necessary treatment in a satisfactory manner.

■ There are 2 types of carriage system:

i. The combined sewer system.

ii. The seperate sewer system.

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1. Hygienic and sanitary aspect : The system is very hygienic since the night soil and other waste water

is conveyed through closed conduits which are not directly exposed to the atmosphere. There is no

bad smell because of continuous flow.

2. Epidemic Aspect: There are no chances of outbreak of epidemic because flies and other insects do

not have direct access to insects do not have direct access to the sewage

3. Pollution Aspect : The liquid wastes etc. are directly conveyed through the sewers, and therefore there

are no changes of the therefore there are no changes of the waste water being soaked in the ground

thus contaminating the soil. No possibility of groundwater contamination.

4. Compactness in design : Since the latrines are flushed after every use, excreta does not remain and

there are no foul smells. The latrines there are no foul smells. The latrines can therefore be attached

to the living and bed rooms. This permits a compact design.

5. Labor Aspect : The labor required for the operation and maintenance is extremely small. Labor may

be required for pumping operations and blockage cleaning.

6. Treatment Aspect : The system permits the use of modern methods of treatment of the sewerage

collected through the sewers. The treated waste water and sewage can be safely disposed off without

any risk.

7. Land Disposal Requirements : Because of treatment facilities, the land required for the disposal of

the treated wastewater is very is very much smaller than· that required for the conservancy system.

8. Cost Consideration : Though the initial cost of installation of the system are very high, the running

costs are very high, the running costs are very small since manual labor is very much reduced.

Advantages of Water Carriage System

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The water carriage system can be divided into the following types:

A. Separate system

B. Combined system

C. Partially separate system

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When separate set of sewers are laid, carrying the sanitary sewage and storm water

it is called Separate system.

When only one set of sewer is laid, carrying both the sanitary sewage and storm

water it is called combined system.

In the separate system, if a portion of storm water is allowed to enter in the sewers

carrying sewage and the remaining storm water flows in separate set of sewers it is

called partially separate system.

■ A. Separate system

• The separate system provides two separatesystems of sewers.

• The one intended for the conveyance of foulsewage only; and the other for the rain water,including the surface washing from certainstreets, overflow from public baths andfoundations etc.

• The sewage from the first system of sewerscan be led to the treatment works, while theflow from the second system of sewers can bedischarged directly to natural streams etc.without any treatment.

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Separate system

ADVANTAGES OF SEPARATE SYSTEM

• Old sewers may also be suitably converted to carry rain water. Thus, the actual sewers

carrying foul sewage will be of smaller size.

• The load on the treatment units will be lowered, since only the foul sewage carried by

the separate sewers need be treated.

• The sewages in the separate system will be of more uniform character, and so will lenditself more easily to purification.

• There is no necessity of providing automatic flushing tanks, for use in dry weather,

because the flow in a sewer of smaller section is much more efficient.

• Sewers of smaller section can be easily ventilated than those of larger section.

• Rain water can be discharged into streams or rivers without any treatment.

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DISADVANTAGES OF SEPARATE SYSTEM

• Since the sewers are of small size, it is difficult to clean.

• They are likely to get choked.

• Two sets of sewers may ultimately prove to be costly.

• There is a likelihood of connections being wrongly made through a confusion of

the systems.

• Storm water sewers or drains comes in use only during the rainy season. During

other part of the year these may serve as dumping place for garbage, and may

get choked.

• Because of lesser air contact in small size sewers, foul smell may be there due to

the sewage gas formed.

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Combined system

• The combined system provides only

one sewer to carry both the foulsewage as well as the rain water.

• The sewage and rain water are

carried to the sewage treatmentplant, before its final disposal.

• The combined system is most suited in

areas having small rainfall which is

evenly distributed throughout the

area, because at such places self-

cleaning velocity will be available in

every season.• As only one sewer is laid in this system,

therefore it can also be used in

crowded areas, where it is very difficult

to lay two sewers.

ADVANTAGES OF COMBINED SYSTEM

• The system requires only one set of sewers. Hence the maintenance costs are reduced.

• The sewers are of larger size, and therefore the chances of their choking are rare. Also, it is

easy to clean them.

• The strength of the sewage is reduced by dilution. There is more air in the larger sewers than in

smaller ones of the separate system. Hence the sewer gas that may be formed gets diluted.

Thus the chances of foul smell are reduced.

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DISADVANTAGES OF COMBINED SYSTEM

• The cost of construction are very high because of large dimensions of the sewers to be

constructed at sufficient depth to receive the sewage from the basement.

• Because of large size of sewers, their handling and transportation is difficult.

• Due to the inclusion of the storm water, the load on the treatment plant increases.

• The system is uneconomical in the circumstances when pumping is required for lifting ofsewage.

• During heavy rains, the sewers may overflow, and may thus create unhygienic

conditions and cause pollution problems.

• Storm water is unnecessarily polluted.

• The large sewers get easily silted if not properly designed. They may become foul in dryweather, when rain water, is not available.

• Large sewers are more difficult to be ventilated than the smaller ones26

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Partially separate system• In this system, only one set of underground sewers is laid.

• These sewers admit the foul sewage as well as the early washings by rains.

• As soon as the quantity of storm water exceeds a certain limit, the storm water overflows, and is

thus collected and conveyed in open drains to the natural streams.

ADVANTAGES• The sewers are of reasonable size. Their cleaning is therefore not very difficult.

• It combines the advantage of both the separate as well as the combined systems.

• The storm water permitted in the sewers eliminates its chances of chocking.

• The sewers are completely cleaned during rainy season.

• The problem of disposing off storm water from homes is simplified.

DISADVANTAGES• During the dry weather, when there is no rain water, the velocity of flow will be low. Thus self

cleansing velocity may not be achieved.

• The storm water increases the load on treatment units.

• The storm water also increases the cost of pumping.

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PARTIALLY

FACTORS AFFECTING SELECTION OF SEPARATE SYSTEM

1.Financial aspects

2.Flat topography 3.Rainfall pattern

4.Outlet conditions

5.Pumping aspect

6.Subsoil conditions

7.Development pattern

FACTORS AFFECTING SELECTION OF COMBINED SYSTEM

1.Space restriction

2.Integrated development

3.Even rainfall pattern4.Conversion of existing storm water drains

5.Pumping requirements

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31Glass fiber reinforced plastic Sewer Pipes

Steel Pipe Sewers

Cement Concrete Sewer Pipes

Clay Pipe Sewers

Brick Sewers

Cement Concrete Sewer Pipes

Sewer SectionsSemi-Elliptical

■ This Section is suitable for sewers Carrying large Discharges throughout the Year. These are Usually Constructed with R.C.C.

Horse Shoe Type

■ This is constructed with R.C.C and is used in case of heavy discharges. Usually it has semi-Circular or parabolic in section. Its height is less than width.

■ Basket Handle The shape of this section is similar to the basket handle therefore it is called as Basket Handle Type.

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Street Inlets

Combined Inlets

■ In combined Inlet the storm waterenters from the top as well as side ofthe catch pit.

Catch Basin

■ These are special types of inlets. Herethe size of the pit is larger andsufficient volume is kept for grit andsand particles to settle and depositat the bottom of the pit.

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Manholes• These are masonry or RCC structures, constructed at suitable intervals along the sewer

lines, for the purpose of cleaning the sewer lines.

• They also help in joining the sewer lines and in changing the direction or alignment aswell as gradients of sewer lines.

• Manholes are directly constructed over the center line of sewer.

• Their shape in plain is circular, rectangular or square.

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Components of Manholes

Access Shaft

■ Upper portion of deep manhole is known as access shaft. It is an access to the

working chamber.

■ Minimum size of access for rectangular manholes is 0.75 m to 0.6 m and for

circular manholes dia of access shaft is 0.7 m

Working Chamber

■ Lower portion of manhole is known as working chamber which provides working

space for cleaning and inspection of sewer line.

■ The minimum size of the working chamber for deep manhole is 1.2 m x 0.9 m

with larger dimension in direction of flow. For Circular manholes the minimum

diameter is 1.2 . The height of the working chamber should preferably be not less

than 1.8 m

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Components of Manholes Access Shaft