1
CHAP TER 1 PROJECT DESCRIPTION IDEA OF FUTURE VISION PROJECT The Future Vision housing scheme project is for providing an economical & perfect residential area for the people especially of the middle class society with the basic requirements. The required sewerage system is to be designed to facilitate the people.
GENERAL DESCRIPTION: The Future vision housing society is a complete residential neighborhood in all respects. The scheme comprises of:  An English-medium school.  Two hundred & Eighty one (281) houses divided into different blocks(A To M).  Three(3) flats & Apartments each.  a well equipped dispensary, with cooperative staff.  Parks.  Graveyard. These facilities provide ease to the residents All the basic necessities including electricity, gas, telephone and water are available. The scheme also has its own waste water treatment plant.. Being adjacent to the Jhelum road, the housing scheme is very easily accessible by road, lying at just 15 minutes drive from Jhelum city.
GEOGRAPHICAL LOCATION: The Future Vision Society is situated on the west bank of the Upper Chenab canal, 10 km along the Jhelum road HOUSING PLAN: The Future Vision Housing project Housing Plan is divided into:  Independent Housing Plots  Apartments(3)  Flats (3)  The independent plots in the society have been divided into 13 housing blocks which are named: A to M for distinction.  The detail of no. of each housing units is given below
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Chapter 2 RELATED THEORY
SEWERAGE: It is the liquid waste or waste water produced as a result of water use.
SEWER: Sewer is a pipe or conduit, generally closed, and flow takes place under gravity.
SOURCES OF WASTE WATER: Sources of waste water or sewage are commonly encountered are: 
Domestic Wastewater It is the waste water from houses, office, other buildings, hotels and institutions.

Industrial Wastewater It is the liquid waste from industrial process.

Storm water It includes surface runoff generated by rainfall and the street wash.
COMPONENTS OF WASTE WATER ENGINEERING: 1) 2) 3)
Collection system (network of sewer pipes) Disposal work (sewage pumping stations, outfalls) Treatment works (for rendering waste water treatment)
TYPES OF SEWERS: 
Sanitary sewer It carries sanitary sewage i.e. waste water from municipality including domestic and industrial waste water.

Storm sewer It carries storm sewage including surface runoff and street wash.

Combined sewer It carries domestic, industrial and storm sewage.

House sewer It is the sewer conveying sewage from plumbing system of a building to common or municipal sewer.

Lateral sewer This sewer carries discharge from house sewer.

Sub main sewer
3 This sewer carries discharge from two or more laterals. 
Main / Trunk sewer It receives discharge from two or more sub mains.

Outfall sewer It receives discharge from all collecting system and conveys it to the point of final disposal.
TYPES OF SEWER SYSTEMS: 
Separate system In this system storm water is carried separately from domestic and industrial waste water.

Combined system In this system sewers carry both sanitary and storm water.
Partially combined system If some portion of storm or surface runoff is allowed to be along with sanitary sewage, the system is known as partially combined system. The sewerage system of the Future Vision scheme has been designed according to partially combined system, being the most economical option in a developing country such as Pakistan. 
DESIGN PERIOD FOR SEWER SYSTEMS: Design of Sewer system Period of design is indefinite, as the system is designed to care for the maximum development of the area. 1)
2)
Design of Sewage pumping station Design period is usually 10 years.
3)
Design of sewage treatment plant Design period is usually 15-20 years.
STRENGHT OF RCC PIPES: Three edge bearing test is used to measure the strength of R.C.C pipes. Load is applied on the pipe to produce 0.25mm crack. The test defines the load that can be safely supported by the sewer.
JOINTS IN SEWER PIPES: There are two types of joints in Concrete (up to 300 mm diameter) and R.C.C pipes (greater than 300 mm diameter)  Bell and Spigot joint (Employed for sewers from 225 mm to 600 mm diameter)  Tongue and groove joint (employed for sizes greater than 600 mm diameter)
SEWER APPURTENANCES: Appurtenances ate those devices, in addition to the pipes and conduits, that all essential for the operation of the sewer system. They include:
4 Manhole (provided when drop is less than 0.6m) Drop manholes (provided when drop is more than 0.6m) 3. Inlets An inlet is an opening into a storm or combined sewer for entrance of storm runoff. It is designed to permit the passage of water from the street surface into the sewer a) Curb inlet b) Gutter inlet c) Catch basins 4. Flush tanks 5. Inverted siphon 1. 2.
6.
PUMPING STATIONS: Used to elevate and transport waste water when:  Continuation of gravity flow is no longer feasible  Basements are deep  Any obstacle lies in the path of sewer  Receiving stream is higher than the sewer  Sewage is to be delivered to and above ground treatment plant
MAIN COMPONENTS OF SEWAGE PUMPING STATION: Screens  Dry well (for installation of pumps)  Wet well (for receipt of waste water)  Pumps (along with valves, force main, motor, control panel etc) 
Design of wet well and pump selection: In small pumping stations, where pump is sized to meet the peak the peak or maximum flow, the following considerations are made:  The detention time in the wet well at average flow should preferably be not more than 30 minutes.  The pump must run for at least 2 minutes  Cycle time must not be less than 10 minute.
CHAPTER 3
DESIGN CRITERIA Complete details are given here regarding all aspects of design of waste water disposal system for this project. The Design procedure aims primarily to determine the:  Diameters  Slopes of the pipes to be laid.
5
THE SEWER SYSTEM: For the type of waste water disposal system, three(3 )options were available as shown below: TYPE OF SEWER SYSTEMS
CHARACTERISTICS
Separate system
All sanitary and storm sewage carried in separate sewer pipes.
Combined system
All sanitary and storm sewage carried in same sewer pipe.
Partially Combined system.
All sanitary sewage carried with a portion of storm sewage or surface runoff in same sewer pipe.
SELECTED SEWER SYSTEM:
Partially Combined system.
DESIGN SEWAGE FLOW CRITERIA In general, the design sewage flow for sewer system is calculated using the following equation:
Design sewage flow = Peak sanitary sewage flow + Storm sewage flow + Infiltration
PEAK SANITARY SEWAGE FLOW: The peak sanitary sewage flow is obtained by application of a “peak factor” to the average sewage flow. Relevant equation is as follows: Peak sanitary sewage flow = Peak factor × Average sanitary sewage flow There are two approaches for determination of peak sewage flow i.e. from WASA specifications or by using the Herman formula.
USING WASA SPECIFICATIONS: For the calculation of peak factor for the design purpose, the 1986 specifications provided by the WASA (Water and Sanitation Agency) have been referred.
AVERAGE SEWAGE FLOW (m3/day)
PEAK FACTOR TO OBTAIN Qmax
≤ 2500
4.00
2500 – 5000
3.40
5000 – 10,000
3.10
10,000 – 25,000
2.70
6 25,000 – 50,000 50,000 – 100,000
2.50 2.30
100,000 – 250,000
2.15
250,000 – 500,000 > 500,000
2.08 2.00
In our case, Peak factor for average sewage flow = 4.0
USING HERMAN FORMULA: An alternative method for determination of peak factor is by using the Herman formula. The formula is given below M
Q MAX 14  1 Q AVG 4 P
DESIGN EQUATION: The Manning’s formula is used for design of sewers flowing under gravity. 2
1
1 v  . R 3 . S2 n Where
v = Velocity of flow (m/sec) R = Hydraulic mean depth =
Area D  (when pipeis flowing full or half full) Wetted perimeter 4
S = Slope of the sewer n = Manning’s coefficient of roughness for pipes (n = 0.013 for RCC pipes)
MINIMUM SELF CLEANSING VELOCITY: It is the minimum velocity that ensures non settlement of suspended matter in the sewer. For Partially combined sewerage system = 0.7 m/sec
Maximum velocity: Maximum velocity should not be greater than 2.4 m/sec to avoid excessive sewer abrasion and also to avoid steep slopes.
MINIMUM SEWER SIZE: The minimum sewer size is taken as 225mm.
MINIMUM COVER: 1m is taken as the minimum cover over the sewers to avoid damage from live loads coming on the sewer.
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SPACING OF MANHOLES sewer size 225mm to 375mm 450mm to 750mm greater than 750mm
spacing 100m 120m 150m
CHAP TER 4 HYDRAULIC STATEMENT & DETAILED DESIGN This chapter deals with the detailed design of future vision housing society. This chapter includes the following:  
Design of partially combined sewer system (hydraulic statement) Design of sewage pumping station (only wet well)
PREPARATION OF HYDRAULIC STATEMENT Hydraulic statement is :  Tabular form or a sheet  Contains information regarding diameters of pipes used, slopes to be maintained, invert levels etc.
REQUIRED DATA FOR THE PREPARATION OF HYDRAULIC STATEMENT POPULATION: The calculation of population was based on the following data: No of Plots No of Apartments No of Flats (2 storey)
= = =
281 3 3
Persons /plot=ten(10) Total population
= =
(281 x 10) + (3 x 600) + (3 x 400) 5810 persons.
PER CAPITA WATER CONSUMPTION:
8 The per capita water consumption is calculated in liters per capita per day (lpcd) using the following relation
PER CAPITA WATER CONSUMPTION = 350 + R Where, R = Registration number of the student = 142 Hence, the per capita water consumption came out to be 492 lpcd.
TOTAL AVERAGE DAILY WATER CONSUMPTION: The relation used for the determination of total average daily consumption of water is as follows: Total ave rage daily water consumption = Pd × Per capita wate r consumption
AVERAGE DAILY SEWAGE FLOW 
80% of average daily water consumption
DESIGN SEWAGE FLOW CRITERIA: 
In general, the design sewage flow for sewer system is calculated using the following equation:

This design sewage flow value is calculated for each sewer line, by determining each of the three parameters given in the equation above. The detail of determination of these parameters follows:
Design sewage flow = Peak sanitary sewage flow + Storm sewage flow + Infiltration
PEAK SANITARY SEWAGE FLOW: The peak sanitary sewage flow is obtained by application of a “peak factor” to the average sewage flow. Relevant equation is as follows: Peak sanitary sewage flow = Peak factor × Average sanitary sewage flow Using WASA Specifications, Peak factor = 4 for our case.
INFILTRATION: Infiltration refers to the wastewater that enters sewers through poor joints, cracked pipes, walls and manhole covers. Infiltration rate = 10 % of average sanitary sewage flow
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DESIGN FLOW: IT is given by the following expression: Design sewage flow = 2 × Peak sanitary sewage flow + Infiltration OR Design sewage flow=8.1*Q(avg.)
LONGITUDINAL PROFILE OF LONGEST SEWER LINE It is always recommended to draw a longitudinal profile of sewer line because:  Helps in executing the work of water disposal system  Guides the contractor to execute the work easily & efficiently. Longitudinal profile is a section along the length showing invert levels, reduced levels, details of manholes, diameter of sewer pipe lines, slope of sewer pipe lines, length of sewer pipe line etc.
SEWER INVERT LEVELS: The lowest inside level at any cross section of a sewer pipe is known as the Invert Level at that cross section.
IMPORTANCE OF INVERT LEVELS:  minimum self cleansing velocity are achieved through calculations of invert levels of sewers at various manholes. Formula for calculation of invert level: U/S Invert level = NGSL/Road level − Depth of sewer − Thickness of sewer − Diameter of sewe r D/S Invert level = U/S Invert level − (Sewer slope × Length of sewer)
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IMPORTANT CONSIDERATIONS IN INVERT LEVEL CALCULATION: 

When sewers of equal diameter discharge in a manhole and a pipe of same diameter receives the total discharge, then the lowest D/S Invert Level among the discharging sewers has been taken as U/S Invert Level of the receiving sewer. When the diameter of receiving sewer is greater than that of lowest discharging sewer the following rules are observed in the laying of sewer pipes: a) The sewer crowns are kept at the same level. b) U/S IL of receiving sewer is dropped by the difference in diameter of the two sewers.
SEWAGE PUMPING STATION: A sewage pumping station is needed to elevate or transport sewage to a higher receiving point in the sewerage system. Such a need can arise when:  Continuation of gravity flow is no longer feasible  Buildings in vicinity have deep basements  An obstacle is present in the path of sewer  Receiving stream is higher than the sewer  Sewage is to be delivered to an above ground treatment plan.
PUMPING CAPACITY & DESIGN SEWAGE FLOW: The sewage pump is design according to the maximum design sewage flow of the total population, and for the current case: Maximum design sewage flow So, required pumping capacity
= 18966.528 m3/day = 13.1712 m3/min = 13.1712 m3/min
AVERAGE SEWAGE FLOW: The average sewage flow rate is used along with the minimum rate of sewage flow to calculate the corresponding “cycle time” for the pumping station: Average sewage flow
= 2341.538 m3/day = 1.626 m3/min
MINIMUM SEWAGE FLOW: Minimum sewage flow = 50 % of ave rage sewage flow Minimum sewage flow = 0.5 x 2341.538 m3/day = 1170.769 m3/day = 0.813 m3/min
CYCLE TIME: The cycle time for a sewage pumping station is the time elapsed between 2 successive startups of the motor pump.
11 Cycle time = Time to empty the wet well + Time to fill the wet well
FORMULA for calculating cycle time
t
V V  PQ Q
VOLUME OF WET WELL: Volume of wet well corresponding to a certain cycle time is given by the following formula: V
t min . P 4
The wet well should have a volume such that the cycle time is always greater than the minimum cycle time recommended for a motor pump.
DESIGN DESIGN CALCULATIONS DESIGN CALCULATIONS DESIGN CALCULATIONS DESIGN CALCULATIONS CALCULATIONS
(PUMPING STATION) Given data: Maximum design sewage flow
Average sewage flow
= Qmax =6.35 m3/min
= 9147.26 m3/day
= Qavg = 2286.82 m3/day =1.58 m3/min
= Qmin= 0.5 * 1.58 m3/day =0.794 m3/min Recommended cycle time for pump = 10 minutes Minimum sewage flow
SOLUTION: Effective volume of wet well
=
P. t min 6..35  10   15.87m 3 4 4
CHECK FOR RUNNING TIME:
t=
V 15.87   2.84min > 2 min ( OK) P  Q min 6.35  0.794
12
CHECK FOR DETENTION TIME: 𝐭=
𝐕 Qavg
=
So, Volume of wet well Assuming Depth Surface Area Diameter
𝟏𝟓.𝟖𝟕 𝟏.𝟓𝟖
= 𝟏𝟎. 𝟎𝟒 𝐦𝐢𝐧𝐭 < 30 min
= =
(ok)
= 15.87 m3 = 2.0 m 7.935m 3.18 m
DIAMETER SELECTED = 3.18 meters
CHAP TER 5 DRAWINGS This chapter deals with the major drawings required for the implementation of the project. The following drawings are included in this chapter: Longitudinal profile of sewer Manhole 3. Sewage pumping station 4. Sewer joints 1. 2.
LONGITUDINAL PROFILE OF THE SEWER Longitudinal profile of the sewer is:  The graphical representation of Hydraulic Statement. In our design of future vision housing society I have drawn the longest sewer profile. The functions of manholes are:
MANHOLES   
Cleaning, inspection of sewer pipe Maintenances of sewer House connections
13
LOCATION OF MANHOLES Manholes should be located where ever there is:   
Change in sewer direction Change in slope Change in diameter
A typical figure of manhole is shown in the below figure.
DROP MANHOLES  
When lateral or sub main join in a deeper sewer, excavation is saved by keeping the upper sewer at a reasonable grade and making the vertical drop at the manhole. Drop manhole is constructed when the drop is more than 0.6m.
A typical figure of drop manhole is shown in the figure.
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SEWAGE PUMPING STATION: A sewage pumping station is needed :  To elevate or transport sewage to a higher receiving point in the sewerage system. Such a need can arise when:     
Continuation of gravity flow is no longer feasible Buildings in vicinity have deep basements An obstacle is present in the path of sewer Receiving stream is higher than the sewer Sewage is to be delivered to an above ground treatment plant
The schematic diagram of the pumping station is given below.
CYCLE TIME: The cycle time for a sewage pumping station is the time elapsed between 2 successive startups of the motor pump. Cycle time is given by the following formula:
t
V V  PQ Q
VOLUME OF WET WELL: V
t min . P 4
SEWER JOINTS: There are two types of joints in Concrete (up to 300 mm diameter) and R.C.C pipes (greater than 300 mm diameter)  Bell and Spigot joint (Employed for sewers from 225 mm to 600 mm diameter)  Tongue and groove joint (employed for sizes greater than 600 mm diameter) The figure of bell and spigot joint and tongue and groove joints is given below.
15
CHAPTER 6
BILL OF QUANTITY (BOQ) & BEDDING (a) Sr No. 1 2 3 4 5 6 7 8 9 10 11 12 13
FOR EXCAVATION
Sewers Diameter Excavation(meters) Quuantity Rate Amount(RS) Description (mm) L(m) W(m) H(m) m3 Rs/C Rupees Millions M1 - M2 225 106 0.638 1.321 89.27 123 10979.79 0.011 M2 – M8 225 37 0.638 1.296 30.57 123 3760.04 0.004 M7 – M8 225 106 0.638 1.321 89.27 123 10979.79 0.011 M8– M10 225 37 0.638 1.346 31.75 123 3905.10 0.004 M9 – M10 225 106 0.638 1.071 72.37 123 8901.86 0.009 M10– M11 310 37 1.598 0.765 45.23 123 5563.46 0.006 M13 – M12 225 89 0.638 1.288 73.08 123 8988.58 0.009 M12 – M11 310 23 0.765 1.324 23.30 123 2865.38 0.003 M11 - M16 380 39 0.870 1.852 62.84 123 7729.12 0.008 M3 - M16 225 110 0.638 1.304 91.44 123 11247.49 0.011 M16 - M17 460 34 0.990 1.925 64.80 123 7969.85 0.008 M4- M17 225 108 0.638 1.275 87.78 123 10797.40 0.011 M17 - M18 460 48 0.990 1.736 82.49 123 10146.85 0.010
16 14 15 16 17 18 19 20 21 22 23 24
M5 - M18 M18 – M19 M6 – M19 M19 – M20 M20– M23 M14 – M15 M15 – M21 M24 – M23 M23 – M21 M21 - M22 M22 –D.S
225 530 310 610 610 225 225 225 310 310 690
110 55 112 42 43 45 163 150 46 15 17
0.638 1.095 0.765 1.215 1.215 0.638 0.638 0.638 0.765 0.765 1.335
1.229 1.625 1.495 1.61 1.154 1.004 0.754 1.206 0.988 0.671 0.859
86.18 97.87 128.09 82.16 60.29 28.80 78.35 115.32 34.77 7.70 19.50
123 123 123 123 123 123 123 123 123 123 123
10600.59 12037.47 15755.27 10105.47 7415.76 3542.68 9637.05 14184.82 4276.43 947.07 2397.89 194735.19
0.011 0.012 0.016 0.010 0.007 0.004 0.010 0.014 0.004 0.001 0.002 0.195
TOTAL COST OF EXCAVATION =0.195 MILLIONS
,
(B)FOR SEWER MATERIAL Sr. No.
Description
1
225mm Ф Sewer
1167
Meters
2
310mm Ф Sewer
236
Meters
3
380mm Ф Sewer
39
Meters
4 5 6 7
460mm Ф Sewer 530mm Ф Sewer 610mm Ф Sewer 690mm Ф Sewer
Quantity
2 82 85 17
Unit
Meters Meters Meters Meters
Total cost for sewerage=1.94 Millions
Rate(RS/m)
Amount(RS)
886.1
1034078.7
1354.95
319768.2
1669.2
65098.8
2104.3
4208.6
2573.65 2992.35 3575.55
211039.3 254349.75 60784.35 1949327.7
17
BEDDING PROVIDED Prov Dia (m)
H(m)
B(m)
C
H/B
Load (Lbs/ft/ft
3 edge bearing Standard value(lb/ft/ft
3 edge bearing value for prov dia.
Load(kg/m
0.225 0.225 0.225 0.225 0.225
1.321 1.296 1.321 1.346 1.071
2.46 0.64
1.66
2.07
1237.65
2722.84
1500
1107.3
0.64
1.64
2.03
1219.08
2681.99
1500
1107.3
0.64
1.66
2.07
1237.65
2722.84
1500
1107.3
2.42 2.46 2.50 0.64
1.69
2.11
1256.06
2763.33
1500
1107.3 2.08
0.64
1.40
1.68
1044.56
2298.04
1500
1107.3 2.59
0.31
1.598
0.77
1.67
2.09
1793.56
3945.83
1500
1525.6
0.225
1.288
0.64
1.63
2.02
1213.11
2668.84
1500
1107.3
0.31
1.324
0.77
1.44
1.73
1541.50
3391.29
1500
1525.6
0.38
1.852
0.87
1.70
2.13
2354.40
5179.68
1500
1870.1
0.225
1.304
0.46
1.925
0.225
1.275
0.64
1.62
2.00
1203.36
2647.40
1500
1107.3
0.46
1.736
0.99
1.45
1.75
2609.50
5740.90
1500
2263.8
0.225
1.229
0.64
1.57
1.93
1168.53
2570.76
1500
1107.3
0.53
1.625
1.1
1.27
1.48
2778.13
6111.89
1500
2608.3
0.31
1.495
0.77
1.59
1.95
1701.13
3742.48
1500
1525.6
0.61 0.61
1.61
0.225 0.225 0.225 0.31 0.31 0.69
1.154 1.004 0.754 1.206 0.988 0.671 0.859
Load factor
2.41 2.22 2.77 2.43 0.64
1.65
2.05
1225.04
2695.10
1500
1107.3 2.76
0.99
1.58
1.94
2837.49
6242.49
1500
2263.8 2.39 2.54 2.32 2.34 2.45 2.28
1.22 1.22
1.15 0.86
1.33 0.95
3105.20 2315.54
6831.43 5094.18
1500 1500
3002.0 3002.0
0.64 0.64
1.33 1.04
1.57 1.18
989.92 774.51
2177.83 1703.92
1500 1500
1107.3 1107.3
0.64 0.77 0.77 1.34
1.55 1.12 0.80 0.60
1.89 1.29 0.88 0.64
1150.90 1204.02 854.30 1956.82
2531.97 2648.84 1879.45 4305.01
1500 1500 1500 1500
1107.3 1525.6 1525.6 3395.7
1.70 1.97 1.54 2.29 1.74 1.23 1.27
Bedding suggested
concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle Brick Ballast Crushed Stone Brick Ballast concrete cradle Brick Ballast Brick Ballast Brick Ballast
18
CHAP TER 7
RECOMMENDATIONS & COMMENTS 
I have Carried out the design of this waste water disposal system for the Future Vision housing scheme with great zeal and the design is complete & will work for the betterment of the people.

Design report is prepared considering all possible features.

Manhole are provided where they were required.

Standard diameters of the pipes have been selected.

Pipes with sufficient length have been provided.

Prper joints have been suggested based on the diameter provided for the pipes.

Required cost for laying the pipes has also been calculated.

The bedding is selected on the basic of required load factor.

Rats for the sewer pipes & excavation were picked from the finance department website. (http://punjab.gov.pk/aug-jan-2013)

I have also suggested the type of bedding based on the considerations given by WASA LAhORE.

For the effective utilization of the system cleaning and inspection be conducted after a proper time duration.

I have not provided the flush tank as they were not required.

Proper maintenances should be provided when required.

Proper maintenances of pumps are also required at regular interval.

In the end,I will conclude that this complete design of partially combined sewer improved my knowledge the design of this system done by me will work very efficiently.
.
MUHAMMAD USMAN 2009-CIVIL-142 SECTION C

1
CHAP TER 1 PROJECT DESCRIPTION IDEA OF FUTURE VISION PROJECT The Future Vision housing scheme project is for providing an economical & perfect residential area for the people especially of the middle class society with the basic requirements. The required sewerage system is to be designed to facilitate the people.
GENERAL DESCRIPTION: The Future vision housing society is a complete residential neighborhood in all respects. The scheme comprises of:  An English-medium school.  Two hundred & Eighty one (281) houses divided into different blocks(A To M).  Three(3) flats & Apartments each.  a well equipped dispensary, with cooperative staff.  Parks.  Graveyard. These facilities provide ease to the residents All the basic necessities including electricity, gas, telephone and water are available. The scheme also has its own waste water treatment plant.. Being adjacent to the Jhelum road, the housing scheme is very easily accessible by road, lying at just 15 minutes drive from Jhelum city.
GEOGRAPHICAL LOCATION: The Future Vision Society is situated on the west bank of the Upper Chenab canal, 10 km along the Jhelum road HOUSING PLAN: The Future Vision Housing project Housing Plan is divided into:  Independent Housing Plots  Apartments(3)  Flats (3)  The independent plots in the society have been divided into 13 housing blocks which are named: A to M for distinction.  The detail of no. of each housing units is given below
2
Chapter 2 RELATED THEORY
SEWERAGE: It is the liquid waste or waste water produced as a result of water use.
SEWER: Sewer is a pipe or conduit, generally closed, and flow takes place under gravity.
SOURCES OF WASTE WATER: Sources of waste water or sewage are commonly encountered are: 
Domestic Wastewater It is the waste water from houses, office, other buildings, hotels and institutions.

Industrial Wastewater It is the liquid waste from industrial process.

Storm water It includes surface runoff generated by rainfall and the street wash.
COMPONENTS OF WASTE WATER ENGINEERING: 1) 2) 3)
Collection system (network of sewer pipes) Disposal work (sewage pumping stations, outfalls) Treatment works (for rendering waste water treatment)
TYPES OF SEWERS: 
Sanitary sewer It carries sanitary sewage i.e. waste water from municipality including domestic and industrial waste water.

Storm sewer It carries storm sewage including surface runoff and street wash.

Combined sewer It carries domestic, industrial and storm sewage.

House sewer It is the sewer conveying sewage from plumbing system of a building to common or municipal sewer.

Lateral sewer This sewer carries discharge from house sewer.

Sub main sewer
3 This sewer carries discharge from two or more laterals. 
Main / Trunk sewer It receives discharge from two or more sub mains.

Outfall sewer It receives discharge from all collecting system and conveys it to the point of final disposal.
TYPES OF SEWER SYSTEMS: 
Separate system In this system storm water is carried separately from domestic and industrial waste water.

Combined system In this system sewers carry both sanitary and storm water.
Partially combined system If some portion of storm or surface runoff is allowed to be along with sanitary sewage, the system is known as partially combined system. The sewerage system of the Future Vision scheme has been designed according to partially combined system, being the most economical option in a developing country such as Pakistan. 
DESIGN PERIOD FOR SEWER SYSTEMS: Design of Sewer system Period of design is indefinite, as the system is designed to care for the maximum development of the area. 1)
2)
Design of Sewage pumping station Design period is usually 10 years.
3)
Design of sewage treatment plant Design period is usually 15-20 years.
STRENGHT OF RCC PIPES: Three edge bearing test is used to measure the strength of R.C.C pipes. Load is applied on the pipe to produce 0.25mm crack. The test defines the load that can be safely supported by the sewer.
JOINTS IN SEWER PIPES: There are two types of joints in Concrete (up to 300 mm diameter) and R.C.C pipes (greater than 300 mm diameter)  Bell and Spigot joint (Employed for sewers from 225 mm to 600 mm diameter)  Tongue and groove joint (employed for sizes greater than 600 mm diameter)
SEWER APPURTENANCES: Appurtenances ate those devices, in addition to the pipes and conduits, that all essential for the operation of the sewer system. They include:
4 Manhole (provided when drop is less than 0.6m) Drop manholes (provided when drop is more than 0.6m) 3. Inlets An inlet is an opening into a storm or combined sewer for entrance of storm runoff. It is designed to permit the passage of water from the street surface into the sewer a) Curb inlet b) Gutter inlet c) Catch basins 4. Flush tanks 5. Inverted siphon 1. 2.
6.
PUMPING STATIONS: Used to elevate and transport waste water when:  Continuation of gravity flow is no longer feasible  Basements are deep  Any obstacle lies in the path of sewer  Receiving stream is higher than the sewer  Sewage is to be delivered to and above ground treatment plant
MAIN COMPONENTS OF SEWAGE PUMPING STATION: Screens  Dry well (for installation of pumps)  Wet well (for receipt of waste water)  Pumps (along with valves, force main, motor, control panel etc) 
Design of wet well and pump selection: In small pumping stations, where pump is sized to meet the peak the peak or maximum flow, the following considerations are made:  The detention time in the wet well at average flow should preferably be not more than 30 minutes.  The pump must run for at least 2 minutes  Cycle time must not be less than 10 minute.
CHAPTER 3
DESIGN CRITERIA Complete details are given here regarding all aspects of design of waste water disposal system for this project. The Design procedure aims primarily to determine the:  Diameters  Slopes of the pipes to be laid.
5
THE SEWER SYSTEM: For the type of waste water disposal system, three(3 )options were available as shown below: TYPE OF SEWER SYSTEMS
CHARACTERISTICS
Separate system
All sanitary and storm sewage carried in separate sewer pipes.
Combined system
All sanitary and storm sewage carried in same sewer pipe.
Partially Combined system.
All sanitary sewage carried with a portion of storm sewage or surface runoff in same sewer pipe.
SELECTED SEWER SYSTEM:
Partially Combined system.
DESIGN SEWAGE FLOW CRITERIA In general, the design sewage flow for sewer system is calculated using the following equation:
Design sewage flow = Peak sanitary sewage flow + Storm sewage flow + Infiltration
PEAK SANITARY SEWAGE FLOW: The peak sanitary sewage flow is obtained by application of a “peak factor” to the average sewage flow. Relevant equation is as follows: Peak sanitary sewage flow = Peak factor × Average sanitary sewage flow There are two approaches for determination of peak sewage flow i.e. from WASA specifications or by using the Herman formula.
USING WASA SPECIFICATIONS: For the calculation of peak factor for the design purpose, the 1986 specifications provided by the WASA (Water and Sanitation Agency) have been referred.
AVERAGE SEWAGE FLOW (m3/day)
PEAK FACTOR TO OBTAIN Qmax
≤ 2500
4.00
2500 – 5000
3.40
5000 – 10,000
3.10
10,000 – 25,000
2.70
6 25,000 – 50,000 50,000 – 100,000
2.50 2.30
100,000 – 250,000
2.15
250,000 – 500,000 > 500,000
2.08 2.00
In our case, Peak factor for average sewage flow = 4.0
USING HERMAN FORMULA: An alternative method for determination of peak factor is by using the Herman formula. The formula is given below M
Q MAX 14  1 Q AVG 4 P
DESIGN EQUATION: The Manning’s formula is used for design of sewers flowing under gravity. 2
1
1 v  . R 3 . S2 n Where
v = Velocity of flow (m/sec) R = Hydraulic mean depth =
Area D  (when pipeis flowing full or half full) Wetted perimeter 4
S = Slope of the sewer n = Manning’s coefficient of roughness for pipes (n = 0.013 for RCC pipes)
MINIMUM SELF CLEANSING VELOCITY: It is the minimum velocity that ensures non settlement of suspended matter in the sewer. For Partially combined sewerage system = 0.7 m/sec
Maximum velocity: Maximum velocity should not be greater than 2.4 m/sec to avoid excessive sewer abrasion and also to avoid steep slopes.
MINIMUM SEWER SIZE: The minimum sewer size is taken as 225mm.
MINIMUM COVER: 1m is taken as the minimum cover over the sewers to avoid damage from live loads coming on the sewer.
7
SPACING OF MANHOLES sewer size 225mm to 375mm 450mm to 750mm greater than 750mm
spacing 100m 120m 150m
CHAP TER 4 HYDRAULIC STATEMENT & DETAILED DESIGN This chapter deals with the detailed design of future vision housing society. This chapter includes the following:  
Design of partially combined sewer system (hydraulic statement) Design of sewage pumping station (only wet well)
PREPARATION OF HYDRAULIC STATEMENT Hydraulic statement is :  Tabular form or a sheet  Contains information regarding diameters of pipes used, slopes to be maintained, invert levels etc.
REQUIRED DATA FOR THE PREPARATION OF HYDRAULIC STATEMENT POPULATION: The calculation of population was based on the following data: No of Plots No of Apartments No of Flats (2 storey)
= = =
281 3 3
Persons /plot=ten(10) Total population
= =
(281 x 10) + (3 x 600) + (3 x 400) 5810 persons.
PER CAPITA WATER CONSUMPTION:
8 The per capita water consumption is calculated in liters per capita per day (lpcd) using the following relation
PER CAPITA WATER CONSUMPTION = 350 + R Where, R = Registration number of the student = 142 Hence, the per capita water consumption came out to be 492 lpcd.
TOTAL AVERAGE DAILY WATER CONSUMPTION: The relation used for the determination of total average daily consumption of water is as follows: Total ave rage daily water consumption = Pd × Per capita wate r consumption
AVERAGE DAILY SEWAGE FLOW 
80% of average daily water consumption
DESIGN SEWAGE FLOW CRITERIA: 
In general, the design sewage flow for sewer system is calculated using the following equation:

This design sewage flow value is calculated for each sewer line, by determining each of the three parameters given in the equation above. The detail of determination of these parameters follows:
Design sewage flow = Peak sanitary sewage flow + Storm sewage flow + Infiltration
PEAK SANITARY SEWAGE FLOW: The peak sanitary sewage flow is obtained by application of a “peak factor” to the average sewage flow. Relevant equation is as follows: Peak sanitary sewage flow = Peak factor × Average sanitary sewage flow Using WASA Specifications, Peak factor = 4 for our case.
INFILTRATION: Infiltration refers to the wastewater that enters sewers through poor joints, cracked pipes, walls and manhole covers. Infiltration rate = 10 % of average sanitary sewage flow
9
DESIGN FLOW: IT is given by the following expression: Design sewage flow = 2 × Peak sanitary sewage flow + Infiltration OR Design sewage flow=8.1*Q(avg.)
LONGITUDINAL PROFILE OF LONGEST SEWER LINE It is always recommended to draw a longitudinal profile of sewer line because:  Helps in executing the work of water disposal system  Guides the contractor to execute the work easily & efficiently. Longitudinal profile is a section along the length showing invert levels, reduced levels, details of manholes, diameter of sewer pipe lines, slope of sewer pipe lines, length of sewer pipe line etc.
SEWER INVERT LEVELS: The lowest inside level at any cross section of a sewer pipe is known as the Invert Level at that cross section.
IMPORTANCE OF INVERT LEVELS:  minimum self cleansing velocity are achieved through calculations of invert levels of sewers at various manholes. Formula for calculation of invert level: U/S Invert level = NGSL/Road level − Depth of sewer − Thickness of sewer − Diameter of sewe r D/S Invert level = U/S Invert level − (Sewer slope × Length of sewer)
10
IMPORTANT CONSIDERATIONS IN INVERT LEVEL CALCULATION: 

When sewers of equal diameter discharge in a manhole and a pipe of same diameter receives the total discharge, then the lowest D/S Invert Level among the discharging sewers has been taken as U/S Invert Level of the receiving sewer. When the diameter of receiving sewer is greater than that of lowest discharging sewer the following rules are observed in the laying of sewer pipes: a) The sewer crowns are kept at the same level. b) U/S IL of receiving sewer is dropped by the difference in diameter of the two sewers.
SEWAGE PUMPING STATION: A sewage pumping station is needed to elevate or transport sewage to a higher receiving point in the sewerage system. Such a need can arise when:  Continuation of gravity flow is no longer feasible  Buildings in vicinity have deep basements  An obstacle is present in the path of sewer  Receiving stream is higher than the sewer  Sewage is to be delivered to an above ground treatment plan.
PUMPING CAPACITY & DESIGN SEWAGE FLOW: The sewage pump is design according to the maximum design sewage flow of the total population, and for the current case: Maximum design sewage flow So, required pumping capacity
= 18966.528 m3/day = 13.1712 m3/min = 13.1712 m3/min
AVERAGE SEWAGE FLOW: The average sewage flow rate is used along with the minimum rate of sewage flow to calculate the corresponding “cycle time” for the pumping station: Average sewage flow
= 2341.538 m3/day = 1.626 m3/min
MINIMUM SEWAGE FLOW: Minimum sewage flow = 50 % of ave rage sewage flow Minimum sewage flow = 0.5 x 2341.538 m3/day = 1170.769 m3/day = 0.813 m3/min
CYCLE TIME: The cycle time for a sewage pumping station is the time elapsed between 2 successive startups of the motor pump.
11 Cycle time = Time to empty the wet well + Time to fill the wet well
FORMULA for calculating cycle time
t
V V  PQ Q
VOLUME OF WET WELL: Volume of wet well corresponding to a certain cycle time is given by the following formula: V
t min . P 4
The wet well should have a volume such that the cycle time is always greater than the minimum cycle time recommended for a motor pump.
DESIGN DESIGN CALCULATIONS DESIGN CALCULATIONS DESIGN CALCULATIONS DESIGN CALCULATIONS CALCULATIONS
(PUMPING STATION) Given data: Maximum design sewage flow
Average sewage flow
= Qmax =6.35 m3/min
= 9147.26 m3/day
= Qavg = 2286.82 m3/day =1.58 m3/min
= Qmin= 0.5 * 1.58 m3/day =0.794 m3/min Recommended cycle time for pump = 10 minutes Minimum sewage flow
SOLUTION: Effective volume of wet well
=
P. t min 6..35  10   15.87m 3 4 4
CHECK FOR RUNNING TIME:
t=
V 15.87   2.84min > 2 min ( OK) P  Q min 6.35  0.794
12
CHECK FOR DETENTION TIME: 𝐭=
𝐕 Qavg
=
So, Volume of wet well Assuming Depth Surface Area Diameter
𝟏𝟓.𝟖𝟕 𝟏.𝟓𝟖
= 𝟏𝟎. 𝟎𝟒 𝐦𝐢𝐧𝐭 < 30 min
= =
(ok)
= 15.87 m3 = 2.0 m 7.935m 3.18 m
DIAMETER SELECTED = 3.18 meters
CHAP TER 5 DRAWINGS This chapter deals with the major drawings required for the implementation of the project. The following drawings are included in this chapter: Longitudinal profile of sewer Manhole 3. Sewage pumping station 4. Sewer joints 1. 2.
LONGITUDINAL PROFILE OF THE SEWER Longitudinal profile of the sewer is:  The graphical representation of Hydraulic Statement. In our design of future vision housing society I have drawn the longest sewer profile. The functions of manholes are:
MANHOLES   
Cleaning, inspection of sewer pipe Maintenances of sewer House connections
13
LOCATION OF MANHOLES Manholes should be located where ever there is:   
Change in sewer direction Change in slope Change in diameter
A typical figure of manhole is shown in the below figure.
DROP MANHOLES  
When lateral or sub main join in a deeper sewer, excavation is saved by keeping the upper sewer at a reasonable grade and making the vertical drop at the manhole. Drop manhole is constructed when the drop is more than 0.6m.
A typical figure of drop manhole is shown in the figure.
14
SEWAGE PUMPING STATION: A sewage pumping station is needed :  To elevate or transport sewage to a higher receiving point in the sewerage system. Such a need can arise when:     
Continuation of gravity flow is no longer feasible Buildings in vicinity have deep basements An obstacle is present in the path of sewer Receiving stream is higher than the sewer Sewage is to be delivered to an above ground treatment plant
The schematic diagram of the pumping station is given below.
CYCLE TIME: The cycle time for a sewage pumping station is the time elapsed between 2 successive startups of the motor pump. Cycle time is given by the following formula:
t
V V  PQ Q
VOLUME OF WET WELL: V
t min . P 4
SEWER JOINTS: There are two types of joints in Concrete (up to 300 mm diameter) and R.C.C pipes (greater than 300 mm diameter)  Bell and Spigot joint (Employed for sewers from 225 mm to 600 mm diameter)  Tongue and groove joint (employed for sizes greater than 600 mm diameter) The figure of bell and spigot joint and tongue and groove joints is given below.
15
CHAPTER 6
BILL OF QUANTITY (BOQ) & BEDDING (a) Sr No. 1 2 3 4 5 6 7 8 9 10 11 12 13
FOR EXCAVATION
Sewers Diameter Excavation(meters) Quuantity Rate Amount(RS) Description (mm) L(m) W(m) H(m) m3 Rs/C Rupees Millions M1 - M2 225 106 0.638 1.321 89.27 123 10979.79 0.011 M2 – M8 225 37 0.638 1.296 30.57 123 3760.04 0.004 M7 – M8 225 106 0.638 1.321 89.27 123 10979.79 0.011 M8– M10 225 37 0.638 1.346 31.75 123 3905.10 0.004 M9 – M10 225 106 0.638 1.071 72.37 123 8901.86 0.009 M10– M11 310 37 1.598 0.765 45.23 123 5563.46 0.006 M13 – M12 225 89 0.638 1.288 73.08 123 8988.58 0.009 M12 – M11 310 23 0.765 1.324 23.30 123 2865.38 0.003 M11 - M16 380 39 0.870 1.852 62.84 123 7729.12 0.008 M3 - M16 225 110 0.638 1.304 91.44 123 11247.49 0.011 M16 - M17 460 34 0.990 1.925 64.80 123 7969.85 0.008 M4- M17 225 108 0.638 1.275 87.78 123 10797.40 0.011 M17 - M18 460 48 0.990 1.736 82.49 123 10146.85 0.010
16 14 15 16 17 18 19 20 21 22 23 24
M5 - M18 M18 – M19 M6 – M19 M19 – M20 M20– M23 M14 – M15 M15 – M21 M24 – M23 M23 – M21 M21 - M22 M22 –D.S
225 530 310 610 610 225 225 225 310 310 690
110 55 112 42 43 45 163 150 46 15 17
0.638 1.095 0.765 1.215 1.215 0.638 0.638 0.638 0.765 0.765 1.335
1.229 1.625 1.495 1.61 1.154 1.004 0.754 1.206 0.988 0.671 0.859
86.18 97.87 128.09 82.16 60.29 28.80 78.35 115.32 34.77 7.70 19.50
123 123 123 123 123 123 123 123 123 123 123
10600.59 12037.47 15755.27 10105.47 7415.76 3542.68 9637.05 14184.82 4276.43 947.07 2397.89 194735.19
0.011 0.012 0.016 0.010 0.007 0.004 0.010 0.014 0.004 0.001 0.002 0.195
TOTAL COST OF EXCAVATION =0.195 MILLIONS
,
(B)FOR SEWER MATERIAL Sr. No.
Description
1
225mm Ф Sewer
1167
Meters
2
310mm Ф Sewer
236
Meters
3
380mm Ф Sewer
39
Meters
4 5 6 7
460mm Ф Sewer 530mm Ф Sewer 610mm Ф Sewer 690mm Ф Sewer
Quantity
2 82 85 17
Unit
Meters Meters Meters Meters
Total cost for sewerage=1.94 Millions
Rate(RS/m)
Amount(RS)
886.1
1034078.7
1354.95
319768.2
1669.2
65098.8
2104.3
4208.6
2573.65 2992.35 3575.55
211039.3 254349.75 60784.35 1949327.7
17
BEDDING PROVIDED Prov Dia (m)
H(m)
B(m)
C
H/B
Load (Lbs/ft/ft
3 edge bearing Standard value(lb/ft/ft
3 edge bearing value for prov dia.
Load(kg/m
0.225 0.225 0.225 0.225 0.225
1.321 1.296 1.321 1.346 1.071
2.46 0.64
1.66
2.07
1237.65
2722.84
1500
1107.3
0.64
1.64
2.03
1219.08
2681.99
1500
1107.3
0.64
1.66
2.07
1237.65
2722.84
1500
1107.3
2.42 2.46 2.50 0.64
1.69
2.11
1256.06
2763.33
1500
1107.3 2.08
0.64
1.40
1.68
1044.56
2298.04
1500
1107.3 2.59
0.31
1.598
0.77
1.67
2.09
1793.56
3945.83
1500
1525.6
0.225
1.288
0.64
1.63
2.02
1213.11
2668.84
1500
1107.3
0.31
1.324
0.77
1.44
1.73
1541.50
3391.29
1500
1525.6
0.38
1.852
0.87
1.70
2.13
2354.40
5179.68
1500
1870.1
0.225
1.304
0.46
1.925
0.225
1.275
0.64
1.62
2.00
1203.36
2647.40
1500
1107.3
0.46
1.736
0.99
1.45
1.75
2609.50
5740.90
1500
2263.8
0.225
1.229
0.64
1.57
1.93
1168.53
2570.76
1500
1107.3
0.53
1.625
1.1
1.27
1.48
2778.13
6111.89
1500
2608.3
0.31
1.495
0.77
1.59
1.95
1701.13
3742.48
1500
1525.6
0.61 0.61
1.61
0.225 0.225 0.225 0.31 0.31 0.69
1.154 1.004 0.754 1.206 0.988 0.671 0.859
Load factor
2.41 2.22 2.77 2.43 0.64
1.65
2.05
1225.04
2695.10
1500
1107.3 2.76
0.99
1.58
1.94
2837.49
6242.49
1500
2263.8 2.39 2.54 2.32 2.34 2.45 2.28
1.22 1.22
1.15 0.86
1.33 0.95
3105.20 2315.54
6831.43 5094.18
1500 1500
3002.0 3002.0
0.64 0.64
1.33 1.04
1.57 1.18
989.92 774.51
2177.83 1703.92
1500 1500
1107.3 1107.3
0.64 0.77 0.77 1.34
1.55 1.12 0.80 0.60
1.89 1.29 0.88 0.64
1150.90 1204.02 854.30 1956.82
2531.97 2648.84 1879.45 4305.01
1500 1500 1500 1500
1107.3 1525.6 1525.6 3395.7
1.70 1.97 1.54 2.29 1.74 1.23 1.27
Bedding suggested
concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle concrete cradle Brick Ballast Crushed Stone Brick Ballast concrete cradle Brick Ballast Brick Ballast Brick Ballast
18
CHAP TER 7
RECOMMENDATIONS & COMMENTS 
I have Carried out the design of this waste water disposal system for the Future Vision housing scheme with great zeal and the design is complete & will work for the betterment of the people.

Design report is prepared considering all possible features.

Manhole are provided where they were required.

Standard diameters of the pipes have been selected.

Pipes with sufficient length have been provided.

Prper joints have been suggested based on the diameter provided for the pipes.

Required cost for laying the pipes has also been calculated.

The bedding is selected on the basic of required load factor.

Rats for the sewer pipes & excavation were picked from the finance department website. (http://punjab.gov.pk/aug-jan-2013)

I have also suggested the type of bedding based on the considerations given by WASA LAhORE.

For the effective utilization of the system cleaning and inspection be conducted after a proper time duration.

I have not provided the flush tank as they were not required.

Proper maintenances should be provided when required.

Proper maintenances of pumps are also required at regular interval.

In the end,I will conclude that this complete design of partially combined sewer improved my knowledge the design of this system done by me will work very efficiently.
.
MUHAMMAD USMAN 2009-CIVIL-142 SECTION C