The document discusses sanitary engineering and its importance. It defines sanitation and environmental sanitation as relating to public health through clean drinking water and adequate sewage disposal. Sanitary engineering deals with collecting, conveying, and disposing of wastewater and garbage to maintain a healthy environment. Improper sanitation can lead to odor and water contamination. The importance of sanitary engineering is to understand wastewater constituents and impacts, applicable treatment methods, and sludge reuse options. It also discusses sewage, sewer systems, and the three main types: combined, separate, and partially separate systems.

1. Environmental Engineering II
Lecture No 3
Topic: Sanitary Engineering and Importance of Sanitary Engineering

2. Sanitary Engineering
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• Sanitation: Conditions relating to public health, especially the
provision of clean drinking water and adequate sewage disposal.
• "Environmental sanitation" means the art and science of applying
sanitary, biological and physical science principles and knowledge to
improve and control the environment and factors therein for the
protection of the health and welfare of the public.
• Sanitary Engineering: It is the branch of public health engineering
dealing with the collection, conveyance and disposal of wastage
(garbage, sullage, sewage). The main purpose of sanitary engineering is
to maintain such environment as well not affect the public health in
general.
• Sanitary Engineering is the start point of the end of water supply. It is
thus the operation of collecting wastewater from different generating
sources, proper treatment before its disposal to water bodies or reuse
for different purposes.

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4. Improper Sanitation
• If untreated wastewater is allowed to
accumulate, the decomposition of the
organic materials it contains can lead
to the production of large quantities
of gases causing unfavorable smell in
atmosphere.
• In addition wastewater usually contains
numerous pathogenic microorganisms
came from human being, animals or
from industrial wastes.
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5. Importanceof SanitaryEngineering
To protect the health and environment it is necessary to have a knowledge
of
(i). Constituents present in wastewater.
(ii).Impact of these constituents when wastewater is disposed into
environment.
Reference: The health hazards (both carcinogenic and noncarcinogenic) associated with chronic
intake of arsenic due to drinking arsenic contaminated water have been investigated and well known
(Nickson, 1998;Acharyya, 1999; Ahsan, 2009; Argos, 2010; Shrestha, 2003; Smith, 2009; 1998).
(iii). Treatment methods that can be used to remove or modify the
constituents ; and
(iv) Methods for beneficial use of the impurity generated by the treatment
processes. (Sludge reuse)
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6. Time to think- Assignment
• Wastewater reuse (after treatment).
• Reuse of sludge (As a result of treatment).
• What are the serious drawbacks regarding
wastewater treatment (Recall from the lecture pl)
Peshawar
Islamabad
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7. STP: Sewage Treatment Plant
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8. Basic Definitions
• SEWAGE OR WASTEWATER: Wastewater,
also known as sewage is the liquid
originates from household
human and animal wastes,
wastes
wastes,
industrial wastewaters, storm runoff,
inflow and infiltration.
• Wastewater, is the flow of used water
from a community. It is approximately
99.94% water by weight The remaining
0.06% is material dissolved or suspended
in the water. It is largely the water supply
of a community after it has been fouled
by various uses.
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9. SEWER: The underground conduits or drains through which
sewage is conveyed. Sewer are generally closed, but not flowing
full. The full flowing sewer are known as force main as the flow is
under pressure.
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13. The Basics
• DOMESTIC OR SANITARY SEWAGE: The sewage which originates of
dwellings, commercials or industrial facilities, and institutions is termed as
domestic or sanitary sewage. The sewer used for this purpose is known as
sanitary sewer.
• INDUSTRIALS WASTES: The liquid discharges from industrials processes
like manufacturing and food processing is industrial wastes. The sewer used
for disposing of such wastes is known as industrial sewer.
• STORM SEWAGE: Storm sewage is the flow derived from rainfall events.
The sewer used for this purpose is known as storm sewer.
• INFILTRATION: Infiltration is the water enter into sewer from the ground
through leaks.
• EXFILTRATION: The leakage of water from sewer to ground surface is
exfiltration. It is exit of water from a sewer due to fault/cracks in sewer line.
• INFLOW: It is the water enter to the sewer from surface source through
cracks in manholes and open cleanouts. Inflow usually occurs during runoff.
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Infiltration occurs when groundwater seeps i
n
t
o
sewer pipes through cracks, leaky pipe joints
and/or deteriorated manholes. Inflow is
stormwater that enters the sewer system
through rain leaders, basement sump pumps
or foundation drains illegally connected to
the sewer.
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The Basics
• House Sewer: A pipe conveying wastewater from an individual structure
(house or building) to a common sewer or point of disposal.
• Lateral Sewer: It receive discharge from house sewers.
• Branch sewer: It receive discharge from two or more laterals.
• Submain sewer: It receive discharge from two or more branch sewers
and/or laterals.
• Main sewer: Receive sewage discharge from two or more sub mains/
branches or from laterals.
• Trunk Sewer: When more than one mains meet and form ultimately a single
sewer directed to treatment unit or disposal point is known as trunk sewer.
• Outfall Sewer: Receive discharge from all collecting system and convey it to
the point of final disposal. (e.g a water body etc.)
• Sewage treatment: is the process in which the wastewater is subjected in
order to remove or change its objectionable constituents so as to render it less
dangerous or offensive.

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The Basics
Sewage Disposal: The disposal of sewage by any method to water bodies or land.
Aims and Objects of sewerage Work:sewerage system in a city is provided for
safe disposal of wastewater. For this purposes sewer lines are used, it also prevent
flooding of the area following a rainfall. The main purpose of sewerage system are
as;
• To provide a good sanitary environmental condition in a city.
• The disposal of human excreta to a safe place by a safe and protective means.
• To dispose of all liquid wastes from a community to a proper place for preventing a
favorable condition for mosquito, flies breeding or bacteria growing
• To treat the sewage so as not to endanger the water bodies, or land to get polluted
where it is finally disposed of
• Proper disposal method should be adopted to protect sub soil water from
contamination.

18. Contaminated subsoil
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The Basics
Invert: The lowest point of the inside surface of a sewer or drain at any cross
section. It can be considered the "floor" level. Conversely, the crown level is the
highest interior level, and can be considered the "ceiling" level.
Force main: The pressurized sewer lines which convey sewage from a pumping
station to another main or to a point of treatment or disposal.
Intercepting sewer: It intersects other sewer to separate the dry weather flow from
storm water.
Relief sewer: A sewer constructed to carry a portion of flow in a system when the
flow exceeds the design flow in a original sewer
Combined Sewage: Acombination of sanitary and storm sewage with or without
industrial waste. The sewer used for this purposes is termed as combined sewer
Crude or Raw Sewage: The sewage that has not treated
Dilute or Weak Sewage: Sewage containing less suspended solids.
Fresh Sewage: The sewage that is fresh produced.
Septic or Stale or Old Sewage: Old sewage is also known as septic or stale sewage.

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21. Types of Sewerage System
Three types of sewerage systems:
• Combined system
• Separate System
• Partially separate system
1. Combined system: In combined system along with domestic sewage, the run-
off resulting from storms is carried through the same conduit of sewerage
system.
For Peshawar Municipality (already no wastewater treatment plant is operational) where
rainy days are very few, this system will face the problem of maintaining self
cleansing velocity in the sewers during dry season, as the sewage discharge may
be far lower as compared to the design discharge after including storm water.
( Foryourkind information:There is nostorm sewerdesignedat all)
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22. Types of Sewerage System-Combinedsystem
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23. Types of Sewerage System-Combinedsystem
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24. Types of Sewerage System- SeparateSystem
• Separate System: In separate system, separate conduits are used; one carrying
sewage and other carrying storm water run- off. The storm water collected can be
directly discharged into the water body since the run- off is not as foul as sewage
and no treatment is generally provided. Whereas, the sewage collected from the
city is treated adequately before it is discharged into the water body or used for
irrigation to meet desired standards. Separate system is advantageous and
economical for big towns.
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Types of Sewerage System- Separate System
Advantages:
• Less size of sewer is required.
• Sanitary and storm water flows in separate pipes, the
quantity of sewage to be treated is less.
• If the sewage is to be pumped, the separate system is
cheaper.
• Rain water can be discharged into stream without
treatment.

26. Types of Sewerage System- SeparateSystem
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Types of Sewerage System- Partiallyseparatesystem
• Partially separate system: In this system part of
the storm water especially collected from roofs and
paved courtyards of the buildings is admitted in the
same drain along with sewage from residences and
institutions, etc.
• The storm water from the other places is collected
separately using separate storm water conduits.

28. Types of Sewerage System- Partiallyseparatesystem
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29. Types of Sewerage System- Partiallyseparatesystem
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31. A worker paints the dumpster- Peshawar
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32. Go, went, gone (Dumpsters are missing?)
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33. 98m USD for Municipal Services Peshawar
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34. P.D.A website ??? 2nd in order -Sanitation
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35. Peshawar City
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36. Things need to beimproved
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37. Rescue workers evacuate people stranded in floodwaters in Budhni
Nullah on Charsadda Road (Dawn News)
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