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Detail Project report on Sewage,storm,surfacewater drain,lak protection at Raipur.
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TABLE OF CONTENTS
DETAILED DESIGN REPORT
EXECUTIVE SUMMARY ......................................................................................1
1.0 Introduction ................................................................................................ 12
1.1 History of Project Area ............................................................................... 12
1.2 The Project Area ........................................................................................ 12
1.2.1 Topography.............................................................................................................14 1.2.2 Climate ....................................................................................................................14 1.2.3 Rainfall ....................................................................................................................14 1.2.4 Geology...................................................................................................................14 1.2.5 Seismicity................................................................................................................15
1.3 The Need for Project .................................................................................. 15
1.3.1 Existing Scenario on Sanitation ..............................................................................16
1.4 Objectives of Raipur Municipal Corporation ............................................... 25
1.4.1 The Consultants......................................................................................................25
1.5 Scope of Consultancy Services.................................................................. 25
1.5.1 General Scope of Services .....................................................................................25 1.5.2 Specific Services.....................................................................................................26
1.6 Review of Past Reports/Studies ................................................................. 29
1.7 Format of the Report .................................................................................. 29
2.0 Planning of Sewerage System ................................................................... 31
2.1 Objective of Planning ................................................................................. 31
2.2 Specific Short-Term and Long-Term Planning ........................................... 31
2.3 Expected Outputs....................................................................................... 32
2.3.1 Technical.................................................................................................................32 2.3.2 Socio-economic ......................................................................................................32 2.3.3 Environmental .........................................................................................................33
3.0 Population Projection ................................................................................. 34
3.1 General ...................................................................................................... 34
3.2 City Development Plan (CDP) of Raipur City ............................................. 35
3.3 Consultant’s Projection for Project ............................................................. 35
3.4 Final Population for Design ........................................................................ 36
4.0 Sewage Generation.................................................................................... 37
4.1 General ...................................................................................................... 37
4.2 Water Supply Rate in Project Area............................................................. 37
4.3 Sewage Quantification - Ward wise............................................................ 37
4.3.1 Infiltration.................................................................................................................39
4.4 Total Sewage Generation........................................................................... 40
5 Design Considerations ............................................................................... 41
5.1 Introduction ................................................................................................ 41
5.2 Planning Considerations ............................................................................ 41
5.2.1 Planning Horizon.....................................................................................................41 5.2.2 Present and Future Land Use.................................................................................41
5.3 Sewer Design Considerations .................................................................... 42
5.3.1 General Location Criteria ........................................................................................42 5.3.2 Horizontal Alignment Criteria ..................................................................................43 5.3.3 Vertical Alignment Criteria ......................................................................................44
5.4 Appurtenances ........................................................................................... 45
5.4.1 Manholes.................................................................................................................45 5.4.2 Bedding for Pipes....................................................................................................45
5.5 Concrete Encasement................................................................................ 46
5.6 Railway Crossings...................................................................................... 46
5.7 Highway Crossing ...................................................................................... 46
5.8 Pipe Material .............................................................................................. 47
5.8.1 Technical evaluation of pipe material .....................................................................47 5.8.2 Economic evaluation of pipes .................................................................................48 5.8.3 Recommendations on pipe material .......................................................................48
6.0 Design Criteria............................................................................................ 49
6.1 Design Period............................................................................................. 49
6.2 Peak, Average and Minimum Flows ........................................................... 49
6.3 Sewer Size ................................................................................................. 49
6.4 Slope .......................................................................................................... 49
6.5 Velocity....................................................................................................... 50
6.6 Depth.......................................................................................................... 50
6.7 Design Equation ......................................................................................... 50
6.8 Manholes (Regular and Drop) .................................................................... 52
6.9 Property Connection................................................................................... 52
7.0 Design of Sewers ....................................................................................... 53
7.1 Salient Design Considerations – Gravity Sewers ....................................... 53
7.2 Population Density ..................................................................................... 54
7.3 Sewerage Zones ........................................................................................ 55
7.3.1 Zone – I ...................................................................................................................56 7.3.2 Zone – II ..................................................................................................................57 7.3.3 Zone – III .................................................................................................................58
7.4 Trunk Sewers ............................................................................................. 59
7.4.1 Zone – I ...................................................................................................................59 7.4.2 Zone – II ..................................................................................................................59 7.4.3 Zone – III .................................................................................................................60
7.5 Sewer Design............................................................................................. 60
7.6 Summary of Sewer Design......................................................................... 61
8.0 Sewage Pumping Station ........................................................................... 63
8.1 Site Selection ............................................................................................. 63
8.2 Building and Structures .............................................................................. 63
8.3 Access Road .............................................................................................. 63
8.4 Pumping Capacity ...................................................................................... 63
8.5 Rising Main Hydraulics............................................................................... 63
8.6 System Head Curve ................................................................................... 64
8.7 Wet Well Sizing .......................................................................................... 65
8.8 Mechanical and Electrical Aspects ............................................................. 65
8.9 Other Features ........................................................................................... 66
8.10 Summary of SPS Design............................................................................ 66
9.0 Design of Sewage Treatment Plant............................................................ 67
9.1 General ...................................................................................................... 67
9.2 Sewage Characteristics.............................................................................. 68
9.3 Sewage Treatment Methods ...................................................................... 68
9.3.1 Biological Treatment ...............................................................................................69
9.4 Sewage Treatment Plant Design Considerations ....................................... 75
9.4.1 Planning Considerations .........................................................................................75 9.4.2 Design Considerations............................................................................................76 9.4.3 Process Considerations ..........................................................................................76 9.4.4 Environmental Considerations................................................................................77 9.4.5 Social Considerations .............................................................................................77 9.4.6 Economic Considerations .......................................................................................78
9.5 Sewage Treatment Plant ............................................................................ 78
9.5.1 Performance Evaluation of SBR and ASP..............................................................79 9.5.2 Techno-Economic Evaluation of ASP and SBR .....................................................80 9.5.3 Total Cost of STP....................................................................................................83 9.5.4 Recommendation on Treatment Technology..........................................................83
9.6 Disposal of Treated Effluent ....................................................................... 85
9.6.1 Natural Evaporation ................................................................................................85 9.6.2 Urban Reuse...........................................................................................................85 9.6.3 Industrial Reuse ......................................................................................................85 9.6.4 Agriculture Reuse ...................................................................................................85 9.6.5 Recreational Reuse ................................................................................................85 9.6.6 Ground Water Recharge.........................................................................................86 9.6.7 Discharge into Natural Waters................................................................................86 9.6.8 Flushing of Sewers .................................................................................................86
9.7 Conclusion ................................................................................................. 86
10.0 Environmental Impacts............................................................................... 87
10.1 Objectives of Environmental Impacts ......................................................... 87
10.2 EIA Process................................................................................................ 87
10.2.1 Approach & Methodology for EIA ...........................................................................87 10.2.2 Desk Study and Scoping.........................................................................................87
10.3 Impact Assessment .................................................................................... 89
11.0 Operation and Maintenance ....................................................................... 90
11.1 Necessity of Maintenance .......................................................................... 90
11.2 O&M for the project .................................................................................... 90
11.3 Road Restoration ....................................................................................... 91
12.0 Project Management .................................................................................. 92
12.1 Construction ............................................................................................... 92
12.1.1 Excavation ..............................................................................................................93 12.1.2 Installation of Sewer Pipes......................................................................................93 12.1.3 Bedding ...................................................................................................................93 12.1.4 Handling of Pipes....................................................................................................93 12.1.5 Jointing and Cutting ................................................................................................94 12.1.6 Placing and Compaction of Fill and Backfill...........................................................94 12.1.7 Disposal of Surplus Material ...................................................................................94
12.2 Prefab Reinforced Concrete Manholes ...................................................... 95
12.3 Important Aspects During Construction...................................................... 95
12.4 Standards for Construction....................................................................... 103
12.5 Testing ..................................................................................................... 104
12.5.1 Tests on Completion .............................................................................................104
12.6 Project Management: Construction Stage................................................ 104
12.6.1 Production of Pipes / Manholes at Site.................................................................105 12.6.2 Contractor to Produce Designs.............................................................................105 12.6.3 Software for Project Scheduling and Monitoring ..................................................105
12.7 Project Implementation............................................................................. 105
12.7.1 Implementation Schedule .....................................................................................106
13.0 Cost Estimates ......................................................................................... 111
13.1 Basis of Cost Estimate ............................................................................. 111
13.2 Price Escalation........................................................................................ 112
13.3 Detailed Cost Estimate............................................................................. 112
13.4 Summary of Costs.................................................................................... 115
13.5 Cash Flow Statement ............................................................................... 115
14.0 Financial Analysis..................................................................................... 117
14.1 Financial Management ............................................................................. 117
14.1.1 Tariff Charges .......................................................................................................117 14.1.2 Public-Private-Partnership ....................................................................................117
14.2 Conclusions.............................................................................................. 118
15.0 Conclusions and Recommendations ........................................................ 119
15.1 Conclusions.............................................................................................. 119
15.2 Recommendations ................................................................................... 120
ANNEXURES
1. Ward wise area of Raipur Municipal Corporation
2. Ward wise population projection and Population Projection Report
3. Waste Water Sampling Data for Delhi city and Sewage Characteristics in Raipur City by CGECB, Regional Office, Raipur
4. Type of Growth System and Details of STP under various schemes
5. General Standards for Discharge of Environmental Pollutants
6. Life Cycle Analysis of SBR & ASP Technologies
7. Cash Flow Statement and Implementation Schedule
8. Escalation Circular
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 1 of 120
EXECUTIVE SUMMARY
Raipur city is experiencing growth with corresponding increase in economic and commercial
activities. The city is boasting due to its being the capital city of Chhattisgarh state. There is influx
of population both floating and fixed. The fixed load is due to additional settlements in the city
and floating load is due to various business related people visiting the city. The already
inadequate infrastructure is unable to bear the pressure of increased institutional and
commercial activities.
The population growth experienced so far is expected to continue strongly over the next couple
of decades adding more pressure to the already grossly inadequate sewerage system. If no
action is taken, this is likely to result in contamination of existing surface and underground
sources of water supply for the urban population of Raipur city. For these reasons, it is
imperative that an efficient and effective sewage collection, treatment and disposal system
complimented by a good storm water drainage system be quickly installed to allow Raipur to
meet the health and sanitation needs of the population and to prevent the lack of infrastructure
from hampering economic growth. The planning of a new sewerage system is necessary in order
to enable the communities to establish a clear picture of their responsibilities in use of the
future services. The development objectives of this project are:
a) Better living conditions for the urban and peri-urban people of Raipur by improved
access of the population to safe sewage disposal.
b) Improved Environmental sanitation as a bye product of improved access to sewerage
system, reduced incidence of water and wastewater related diseases and mortality rate
resulting improved health and personal hygiene of people.
Sewerage System
To arrive at a reasonable estimate for the project, it is prudent to refer the ward wise growth
pattern which would best serve the proposed planning area. Hence for year 2042, an urban
population of 24,49,169 souls + 10% additional souls is adopted as per the Population Projection
Report already submitted to Raipur Municipal Corporation. The design of cost-effective and
efficient sewage collection system is accomplished by proper layout and sizing of sewers. The
design period for all sewers in the system is 30 years, while pumping machinery is designed for
15 years. The criteria adopted for design of sewerage system and sewage treatment are as
under;
Dry Weather Flow : 80% of water supply (i.e. 135 lpcd)
Peak Factor : As per CPHEEO Manual
Design Equation : Manning Formula , with n=0.011
Sewer Material : RCC NP2 / NP3 pipe for laterals, collector, sub-trunk and trunk
sewers
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 2 of 120
Velocity : Min. Velocity ≥ 0.6m/s (0.45 m/sin initial reaches)
Max. Velocity ≤ 3m/s
Depth of Flow : All sewers flowing ≤ 0.8 full (CPHEEO)
Infiltration : 5000 lit/Km/day
Minimum Diameter : 150 mm.
Maximum Depth of
Invert
: The maximum depth of invert shall be 6-7m. In exceptional
cases, like crossings, drop manholes and at pumping station
locations larger depths up to 8m is considered (Case specific
basis).
Minimum Cover : Without protection 0.75 m (up to top of pipe)
With protection (encasing) 0.5m (up to top of encasement).
Bedding : Granular compact bedding 150 mm (minimum) or as per design.
Backfill : All Backfills shall be mechanically compacted and compaction
density measured up to acceptable levels or as specified based
on soil analysis.
Joints : Joints shall be flexible with adequate water tightness measures
like cement mortar/rubber ring for RCC pipes. For large pipes
(dia>900mm) pipe joints shall be wrapped with geo-textiles with
300mm overlap on either side of joint (typically S&S Joint).
Testing of Sewer : As per CPHEEO recommendations
Design Loading : Structural design of buried pipes (As per CPHEEO)
Pipe Strength : As per relevant BIS Code
Manholes : Location
(a) At change of slopes in Pipeline
(b) At change of direction
(c) At junctions
(d) At change of pipe diameter
(e) At termination sewer
(f) At any designed special location
Spacing
(a) Up to 900 mm dia -30m c/c
(b) 900 to 1400 mm dia -100m c/c
Manhole Cover Levels : Paved Areas: Cover level = Final paved level
Unpaved Areas: Cover level=Final G.L.+0.10m
Open Spaces: Cover Level=Final G.L.+0.20m
Flood Areas: Cover level= Final G.L.+0.30m
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 3 of 120
Manhole Cover : Steel Fibre Reinforced Concrete (SFRC)
Manhole Material and
Shape
: Prefabricated RCC Circular Manholes with rubber rings for
proper joints.
Use of sulphate resistant cement is recommended
Vent Shafts : Not Recommended
Silt Chambers : Not Recommended
Type of Excavation : Open excavation in all areas. For deep sewers shoring / sheet
piling shall be adopted, as required
Soil Tests : GT investigations to be carried out for determining bearing
capacity of soil.
The sewage generation rate is calculated at 80% of water supply (using 135 lpcd water supply
rate). The area-density method is being adopted to compute the load of flow on each lateral.
Area distribution on each sewer is taken as a trapezoid on either side of pipe. The trapezoid
area obtained is multiplied by the density of population to know the contributory population on
that sewer. Thereafter using 135 lpcd water supply and 80% of it as wastewater, the quantum
of flow load on that sewer is fixed. The minimum diameter of pipe adopted is 150 mm of RCC
NP2 class. Where NP2 pipes fail to withstand the loads, NP3 pipes shall be used.
The economic analysis reveals that DI pipe are more economical diameter / cost wise and they
also give better velocity and smaller diameter. RCC pipes (NP2 and NP3) are cost wise most
economical for all manufactured diameter ranges. Hence for gravity sewers, it is prudent to
adopt RCC pipes because of their low cost and wide availability. For rising mains from pumping
station, the economics of selection is mainly driven by strength of material and tightness of
joints. For pumping mains, it is recommended to use DI (K7) pipes for their cost economy over
CI, excellent strength and long useful life.
Sewerage Zones
The zoning is based on topographical features (slope, water bodies, etc.) of the area and location
of treatment / final disposal point. Topographically, almost 56% of project area is having slope
from south to north direction. The relief ranges from 305 m in west – northwest to 270 m in east
& north-east. The southern boundary follows the Kharun river. This project area is characterized
POPULATION PROJECTION FOR RAIPUR CITY
10.15
12.5113.92
15.34
19.33 19.8920.81 21.36
24.49
0.0
5.0
10.0
15.0
20.0
25.0
30.0
2012 2017 2020 2023 2027 2030 2035 2038 2042
YEAR
PO
PU
LA
TIO
N, L
ak
hs
SEWAGE GENERATION FOR RAIPUR CITY
114.59
140.06155.34
170.63
213.81 219.78229.72 235.68
269.51
0.0
50.0
100.0
150.0
200.0
250.0
300.0
2012 2017 2020 2023 2027 2030 2035 2038 2042
YEAR
SE
WA
GE
GE
NE
RA
TIO
N,
ML
D
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 4 of 120
by presence of many ponds/lakes and nallahs. There are three major relief lines in the project
area which are considered for zoning.
� The eastern part of city, starting from extreme south (ward no. 52) and extending up to
extreme north (ward no. 26).
� The western part of city consisting of northern parts of Hirapur/Jarvay, Sondongari, Gogaon
& Gudhiyari areas and sloping in north direction leading to northern city limits.
� The western part of city on southern side of Hirapur/Jarvay, Sondongari, Gogaon &
Gudhiyari areas and extending towards southern city limits.
Zone – I
This zone forms the eastern part of city. The west side of this zone is bound by Mathpurena,
Santoshi Nagar, Budha Talab, Ganjpara & the railway line to Hawrah. Area of zone-I is about
48.66 sq. km. (i.e. 34.26% of project area). Zone-I comprises ward number 5, 6, 22 to 35, 40, 42
to 51 and the base year population is 3,15,665 souls. The ultimate population for zone-I is
projected as 8,38,128 souls. On the basis of population projections the immediate (year 2012),
intermediate (year 2027) and ultimate (year 2042) sewage generation from this zone is
calculated at 34.09 Mld, 64.96 Mld and 90.52 Mld respectively (refer Table below).
Area, Population and Sewage Generation on Zone - I
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
5 0.43 2383 4540 6327 0.26 0.49 0.68
6 1.85 5863 11172 15567 0.63 1.21 1.68
22 0.41 13229 25209 35126 1.43 2.72 3.79
23 0.87 13758 26215 36528 1.49 2.83 3.95
24 0.46 13451 25631 35715 1.45 2.77 3.86
25 0.59 13847 26386 36767 1.50 2.85 3.97
26 9.92 16017 30520 42527 1.73 3.30 4.59
27 10.68 14186 27031 37666 1.53 2.92 4.07
28 5.84 16635 31698 44168 1.80 3.42 4.77
29 0.95 13936 26554 37001 1.51 2.87 4.00
30 0.58 12402 23632 32929 1.34 2.55 3.56
31 0.39 13728 26159 36450 1.48 2.83 3.94
32 0.75 14361 27365 38131 1.55 2.96 4.12
33 0.45 13252 25251 35185 1.43 2.73 3.80
34 0.49 13870 26429 36827 1.50 2.85 3.98
35 0.87 12541 23896 33297 1.35 2.58 3.60
40 0.44 7942 15133 21086 0.86 1.63 2.28
42 0.89 16164 30800 42917 1.75 3.33 4.64
43 0.72 16390 31231 43518 1.77 3.37 4.70
44 0.61 16042 30568 42594 1.73 3.30 4.60
45 2.01 13461 25649 35740 1.45 2.77 3.86
46 6.90 12517 23851 33233 1.35 2.58 3.59
47 0.46 11599 22103 30798 1.25 2.39 3.33
48 0.47 10480 19970 27827 1.13 2.16 3.01
49 0.09 1720 3277 4566 0.19 0.35 0.49
50 0.36 4885 9309 12971 0.53 1.01 1.40
51 0.19 1005 1915 2668 0.11 0.21 0.29
Total 48.66 315665 601495 838128 34.09 64.96 90.52
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 5 of 120
Zone – II
This zone forms the north-western part of the city and the right portion of this zone is bound by
Raiway line to Howrah and lower portion is marked northern half of Hirapur/Jarvay, Sondongari,
Gogaon and Godhiyari area. Area of zone-II is about 33.97 sq. km. (i.e. 23.92% of project area).
The base year population of this zone is 325,122 souls. On the basis of population projections
the immediate (year 2012), intermediate (year 2027) and ultimate (year 2042) sewage
generation from this zone is calculated at 35.11 Mld, 66.91 Mld and 93.23 Mld respectively
(refer Table below).
Area, Population and Sewage Generation on Zone - II
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
1 7.20 8025 15292 21308 0.87 1.65 2.30
2 4.47 14297 27243 37961 1.54 2.94 4.10
3 1.32 16536 31509 43905 1.79 3.40 4.74
4 5.46 16441 31328 43653 1.78 3.38 4.71
5 2.30 12827 24442 34057 1.39 2.64 3.68
6 2.30 7318 13944 19430 0.79 1.51 2.10
7 1.09 15745 30002 41805 1.70 3.24 4.51
8 0.77 16266 30994 43187 1.76 3.35 4.66
9 1.07 15196 28957 40348 1.64 3.13 4.36
10 0.44 16230 30925 43092 1.75 3.34 4.65
11 0.64 13932 26547 36990 1.50 2.87 3.99
12 0.99 9555 18208 25371 1.03 1.97 2.74
15 0.72 8070 15378 21428 0.87 1.66 2.31
16 0.44 14070 26809 37356 1.52 2.90 4.03
17 0.63 12935 24647 34343 1.40 2.66 3.71
18 0.46 15939 30372 42320 1.72 3.28 4.57
19 0.20 15524 29581 41219 1.68 3.19 4.45
20 0.71 16199 30867 43010 1.75 3.33 4.65
21 0.55 12707 24213 33739 1.37 2.62 3.64
22 0.01 222 423 589 0.02 0.05 0.06
35 0.12 1754 3342 4657 0.19 0.36 0.50
36 0.56 14456 27546 38383 1.56 2.98 4.15
37 0.56 14648 27911 38891 1.58 3.01 4.20
38 0.30 16102 30683 42754 1.74 3.31 4.62
39 0.13 7529 14347 19992 0.81 1.55 2.16
40 0.26 4727 9007 12550 0.51 0.97 1.36
41 0.20 6343 12086 16840 0.69 1.31 1.82
57 0.08 1528 2912 4058 0.17 0.31 0.44
Total 33.97 325122 619516 863238 35.11 66.91 93.23
Zone – III
This zone starts on southern half of Hirapur/Jarvay, Sondongari, Gogaon and Godhiyari area and
forms the south-central part of the city draining towards Kharun river. Zone-III covers about
57.71 sq. km. (i.e. 40.64% of project area). Zone-III comprises ward number 1, 2, 12 to 15, 39, 41,
46 to 70 and the base year population is 3,73,889 souls. On the basis of population projections
the immediate (year 2012), intermediate (year 2027) and ultimate (year 2042) sewage
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 6 of 120
generation from this zone is calculated at 40.91 Mld, 77.95 Mld and 108.62 Mld respectively
(refer Table below).
Area, Population and Sewage Generation on Zone - III
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
1 7.1845 8013 15269 21275 0.87 1.65 2.30
2 0.6985 2233 4256 5930 0.24 0.46 0.64
12 0.5889 5677 10818 15074 0.61 1.17 1.63
13 1.8900 15030 28640 39908 1.62 3.09 4.31
14 3.6500 13180 25114 34993 1.42 2.71 3.78
15 0.6325 7115 13558 18892 0.77 1.46 2.04
39 0.0824 4865 9269 12916 0.53 1.00 1.39
41 0.1940 6278 11962 16668 0.68 1.29 1.80
46 0.5705 1035 1972 2748 0.11 0.21 0.30
47 0.1018 2579 4913 6846 0.28 0.53 0.74
48 0.2501 5579 10631 14813 0.60 1.15 1.60
49 0.6730 13294 25331 35296 1.44 2.74 3.81
50 0.5776 7786 14836 20672 0.84 1.60 2.23
51 2.4306 12896 24573 34241 1.39 2.65 3.70
52 4.3700 14865 28324 39467 1.61 3.06 4.26
53 0.4700 16260 30984 43173 1.76 3.35 4.66
54 1.0400 12995 24762 34503 1.40 2.67 3.73
55 0.2000 15473 29484 41084 1.67 3.18 4.44
56 0.2500 13730 26162 36454 1.48 2.83 3.94
57 0.5449 11096 21143 29461 1.20 2.28 3.18
58 0.2100 12891 24563 34226 1.39 2.65 3.70
59 0.1000 12782 24356 33938 1.38 2.63 3.67
60 1.0300 13291 25325 35288 1.44 2.74 3.81
61 0.3900 13873 26435 36834 1.50 2.85 3.98
62 1.4600 14462 27557 38398 1.56 2.98 4.15
63 9.5200 16396 31242 43532 1.77 3.37 4.70
64 0.5300 15320 29191 40675 1.65 3.15 4.39
65 0.3100 12801 24392 33988 1.38 2.63 3.67
66 0.8000 13295 25333 35299 1.44 2.74 3.81
67 1.6400 15386 29319 40853 1.66 3.17 4.41
68 5.9200 12952 24680 34389 1.40 2.67 3.71
69 2.3200 13918 26521 36955 1.50 2.86 3.99
70 7.0800 16545 31527 43930 1.79 3.40 4.74
Total 57.71 373889 712440 992720 40.38 76.94 107.21
The hydraulics of gravity sewer is modeled for uniform slope between two sections of the
manholes. The minimum velocity is kept as 0.45 m/s in the initial reaches of lateral sewers. This
is considered to reduce the depth of excavation for sewers. Theoretical flow is computed by
adding infiltration flow. On the basis of contributory population on the section, peak factor is
selected to arrive at peak flow. The computed peak flow, diameter of pipe is selected and depth
of flow in pipe is utilized in computing d/D ratio. Simultaneously the carrying capacity of pipe is
checked against the generated peak flow. There after invert level and crown level are computed
using slope and minimum depth of cover.
Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Executive Summary
Meinhardt Singapore Pte Ltd, (India Branch) Page 7 of 120
Where two or more sewers are joining, the crown of sewers is matched and the minimum of
invert level is carried forward for down stream sewer design.
Slope and diameter values are dynamic in the design and can be changed while checking for the
hydraulic properties of sewer, like, v/V, d/D, qf/Q.
Minimum diameter of sewer adopted in design is 150 mm. RCC NP2 and NP3 pipes are proposed
in design. The depth of sewer laying is limited at 7 to 8 m, and an intermediate sewage pumping
station is proposed at such location. The total gravity sewer length proposed under this DPR is
1032 km. The zone wise summary of design is given below.
Summary of Design Length
LENGTH in m ZONE TRUNK NO.
TRUNK SUBTRUNK COLLECTOR LATERAL
TOTAL
LENGTH
(m)
1 2574.34 7187.33 12573.14 15956.56 38291.36
2 2209.95 9465.27 24952.18 59588.59 96215.99
3 2246.03 10496.60 15221.43 37174.58 65138.64
4 2163.69 8276.95 7494.72 1939.34 19874.71
5 2328.37 7714.08 8778.73 5920.23 24741.40
6 1101.75 4753.91 8079.09 9612.74 23547.48
(7, 8 & 9) 7569.98 20638.01 19436.21 10462.37 58106.57
(10 & 11) 4012.31 12930.48 17173.21 10955.40 45071.40
I
TOTAL (I) 24206.43 81462.62 113708.71 151609.80 370987.56
1 2763.82 135581.83 7789.75 6502.18 152637.58
2 2912.32 3959.97 7999.31 11421.63 26293.23
3 2216.81 13691.84 32877.74 43118.21 91904.60
4 2467.20 6904.07 7789.75 6502.18 23663.19
(5) 2392.43 5664.76 3134.18 325.58 11516.95
(6) 2318.23 6161.37 9716.77 5507.84 23704.20
(7) 2175.58 11428.27 15377.13 12261.45 41242.42
(8 & 9) 4746.50 21348.62 25420.51 18626.61 70142.23
II
TOTAL (II) 21992.90 204740.72 110105.12 104265.67 441104.41
1 2622.04 6493.62 5928.07 3476.03 18519.76
2 0.00
3 2722.30 10149.74 18976.69 15171.26 47019.99
4 1886.68 3500.19 3043.30 4378.06 12808.24
5 2665.15 6604.35 11139.22 44802.33 65211.04
6 2882.96 4659.58 2856.05 579.51 10978.10
7 2708.67 5145.73 9118.62 11019.29 27992.31
(8) 1927.47 4497.17 4553.61 3757.92 14736.17
(9) 2208.04 8568.17 7701.85 3514.80 21992.86
III
TOTAL (III) 19623.31 49618.57 63317.41 86699.18 219258.48
TOTAL 65822.64 335821.92 287131.24 342574.65 1031350.45
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Sewage Pumping Station
With reference to the technical comparison between Centrifugal Pumps and Submersible
Pumps, it can be concluded that the Submersible Pump is based on modern developments in
the technology of centrifugal pumps for sewage pumping applications. Development in impeller
design like Semi-Open Type with Contra-Block System, Steel Material of Construction, better
solid handling capacity, better design due to direct mounting of motor shaft on impeller, better
design of motor stator rotor (Aluminium Die Cast) makes the Submersible Centrifugal Pumps
technically more superior. Considering merits, advantages and disadvantages, it is concluded
and recommended that for the Pumping Stations in Raipur sewerage system, the Submersible
Centrifugal Pumps will be more technically appropriate and economically viable.
Under this DPR, 13 submersible pump type sewage pumping stations are proposed to facilitate
conveyance of sewage up to the proposed treatment facilities. The detailed hydraulic design of
pumping stations is placed in Volume – III. The summary of design is given below.
Table 8.1 : Summary of Sewage Pumping Stations
Sr. No. Zone Identification Average Flow
(MLD)
Rising Main
Length (metre)
1 I SPS – A 1.10 30
SPS – B 3.37 30
SPS – C 8.23 930
SPS – D 14.87 1260
SPS – E 87.09 30
2 II SPS – A (Existing) 71.79 40
SPS – B 11.65 35
SPS – C 6.03 1205
SPS – D 8.11 1415
SPS – E 7.91 2155
SPS – F 29.76 840
3 III SPS – A 4.25 775
SPS – B 6.11 1280
Sewage Treatment Plant:
For the intermediate stage of year 2027, a total of 209 Mld sewage would be available for
treatment. The capital cost and annual O&M cost along with capitalized O&M cost (for 15 years
with 12% interest) for ASP and SBR technologies is computed and presented in Table below.
O&M Cost for ASP and SBR STPs (Intermediate Stage – 209 MLD)
Cost (Lakh Rs.) Rank Process
Capital O&M
Per
year
Capitalized
O&M - 15
yrs
Total
(i) (ii) (iii) (i+iii)
1 Sequential Batch Reactor (SBR) 19855 819.28 5580.01 26062.01
2 Activated Sludge Process 20482 1588.40 10818.38 30673.38
Using the computations of land cost, capital investment cost and annualized O&M cost for the
selected options, a final ranking is presented below.
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Total Cost For STPs (Intermediate Stage)
Cost (Lakh Rs.) Rank Process
Land Capital Capitalized O&M
for 15 yrs
Total
1 Sequential Batch Reactor (SBR) 31.65 19855.00 5580.01 25466.66
2 Activated Sludge Process 79.12 20482.00 10818.38 31379.5
As seen from the above comparison, SBR technology is cheaper than Activated Sludge Process
and becomes the economical option considering cost of land, capital investment and annualized
O&M for 15 years tenure. Since Raipur city is expected to have a facelift in future, and keeping
pace with time a technology with excellent treatment efficiency, low life cycle analysis cost and
less land requirement would suit most. Hence Sequential Batch Reactor (SBR) STP is finally
recommended for Raipur. For yielding better results, the RMC has to gear for the arrangements
(like power, O&M inputs) in long run to convert it in a model treatment facility in state.
Treated Effluent Reuse:
Considering the growth of industrial activities in and around Raipur city, the exceptionally high
quality effluent from SBR technology will be an additional resource to augment industrial non-
process water requirement. Potential for agricultural reuse exist, which requires positive
information dissemination to users. The effluent quality expected out of SBR is sufficient to
permit its safe disposal into nearby receiving waters while meeting the statutory requirement of
the state. Therefore, effluent reuse for industrial purpose and partly into natural waters has
been selected.
Environmental Assessment
The overall identification of negative and positive impacts for the project has been carried out
by using matrix. The matrix includes all possible negative and positive impacts associated with
construction of sewerage lines, construction and operation of pumping stations and STPs. The
evaluated environmental impacts of this project along with mitigation measures and
management plans are submitted along with DPR.
Project Management
In order to limit pre-qualification of contractors to only those who are capable of executing the
project, meeting the requirements of quality and timely completion of works, it is proposed to
set stringent pre-qualification criteria for contractors. To select the right type of contractors and
to ensure that project execution is smooth, it is proposed to include certain provisions in the
contract, some of which are (i) Rejection of tenders with abnormally high or abnormally low
prices, (ii) Payment of advance against deployment of construction equipment and machinery in
addition to mobilization advance, (iii) Introduction of a Bonus Clause, (iv) Third party inspection
of piping, accessories and project machinery by reputed inspection agencies., (v) Weightage to
the technical superiority of the bids in addition to prices for award of work based on criteria to
be decided in consultation with RMC.
Cost Estimates
The cost estimate is prepared on the basis of Madhya Pradesh State Unified Schedule of Rates
(effective since September 2002) with 64% escalation, and for items not falling in this schedule
of rates, the rates as given in CPWD, Delhi Schedule of Rates, year 2007 and MP-PHE SOR - 2009
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are adopted. Based on the detailed designs done for gravity sewers of 1032 kms, the cost is
worked out as under;
Particular Description Cost
Sewer Network Zone-I+II+III (142 km2) Rs. 57326.72 Lakhs
Pumping Stations 13 Nos. Rs. 2198.35 Lakhs
Treatment Plant 209 MLD Rs 20482.00 Lakhs (w/o O&M)
Land Acquisition 29.40 + 0.71 ha Rs. 32.41 Lakhs
Summary of Costs
Sr.
No.
Item Cost (Rs.)
Crores
Remarks
1
Sewerage system complete with laterals,
collectors, interceptor sewers + 13 Nos of Sewage
Pumping Stations with DI rising main and all
accessories complete
595.250
1032 km of
gravity sewers
150 – 2200 mm
diameter
2
3 Sewage Treatment Plants on SBR technology
complete in all aspects (zone-I : 65 Mld, zone –II:
67 Mld and zone-III: 77 Mld)
204.82 Only construction
cost
3 O & M Cost for SPS and STP 22.411 cost of O&M of 3
years
4
Land Acquisition Cost for 30.11 hac (for all 3 STPs
& 11 SPS)
0.3241 @ Rs.1 per sq.ft.
5 Environmental Mitigation and Monitoring Cost 0.25
During
construction stage
6 Relocation of Utilities 1.00 Provisional LS
item
7
House Connections for 82200 as per CDP of Raipur
51.349
75000 domestic,
5000 commercial,
2200 industrial
TOTAL 875.3118
Adding 6%* for Contingencies and Departmental
Charges of Total Cost 52.923
Total Cost (Rs. in Crores)
927.830
* percentage approved under Bilaspur Sewerage Project
The major capital cost in this project is for laying of 1032 kms of gravity sewers ranging from 150
mm to 2200 mm diameter. Though the sewer laying is for the betterment of population of
Raipur, but at the same it is the responsibility of RMC to recover the cost of project from the
population benefited by the project. Unlike water supply schemes, where water is charges to the
consumers who are connected to piped water supply, sewerage connections perform poor in
terms of realization of user charges. The CDP targets for providing 75000 domestic sewer
connections, 5000 commercial and 2200 industrial connections by year 2012-2013.
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It becomes compulsory for RMC to provide these connections and steadily increase the
connectivity on sewer system, so as to achieve 100% sanitation and thus improve the functional
efficiency of the assets thus created under this project. Based on the proposed connectivity
targets, the revenue generation and expenditure analysis is separately presented as Volume- 1A
: Financial Analysis, with this report.
Conclusions
RMC has to make a detailed tariff plan considering the improvement in the civic infrastructure of
the city. The tariff plan should be prepared in line so that the expenditure of O&M is covered and
future reserve fund is available for any future expansion. RMC should focus on bringing in a new
unified tariff structure for water and sewerage services immediately. The focus should be on
reforms aiming at providing sustainability of services at least for the O&M component. Following
conclusions are brought out for consideration of RMC.
� Privatize the sanitation services through Concession Agreements
� Immediate augmentation of water resources
� Water conservation through an appropriate tariff structure
� Formulate Policies to attract and support Private sector participation
� Develop water policy guidelines
� Set up an Independent Regulatory Authority
� Rationalize tariffs
***
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Introduction 1111
1.0 Introduction
1.1 History of Project Area
Raipur district is important in historical and archeological point of view. This district was once
part of Southern Kosal and considered to be under Maurya Kingdom. Raipur city had been the
capital of the Haihaya Kings, controlling the traditional forts of the Chhattisgarh for a long time.
The town of Raipur has been in existence since the 9th century, the old site and ruins of the fort
can be seen in the southern part of the city.
On 17 May, 1867 a municipality was created at Raipur. The municipality was reconstructed in
1883, 1903 and 1925-26 under the Central Province and Berar Municipality Act of 1922. In the
year 1961, Madhya Pradesh Municipalities Act (No.37 of 1961) was enacted to consolidate and
amend the law relating to municipalities and to make provision for their better organization and
administration. After enforcement of committee, Raipur was governed and regulated under the
provisions of then aforesaid Act.
In the year 1967, the then State Government of Madhya Pradesh, promulgated the Madhya
Pradesh Municipality Corporation (Amendment) Ordinance 1967(No.7 of 1967) and this
ordinance was made applicable to Raipur City. Consequently the Municipal Council was
upgraded as Municipal Corporation, Raipur from 26th August 1967. Since then, over a period of
time the town has connections for rail, road and air transport modes and now it is the biggest
City in the State of Chhattisgarh. Since formation of Chhattisgarh state, i.e. from 1st November
2000, Raipur became the capital city of the state.
1.2 The Project Area
The Raipur district is located in Chhattisgarh State and falls within Latitude 21014” to 22
033”
North and Longitude 81038” to 82
06” East, covering approximately 15190 sq. km. Raipur district
is bounded by Bilaspur district of the State on North side, Bastar & part of Orissa state in the
South, Raigarh & part of Orissa state on the East and Durg districts in the West. The district
occupies the south-eastern part of upper Mahanadi valley and the bordering hills in the South
and the East. Therefore, the district is divided into two major physical divisions, the Chhattisgarh
plains and hilly areas. Raipur town is headquarter and the biggest town of the district.
Raipur lies on Bilaspur-Durg section of the Mumbai-Howrah broad guage line of the
Southeastern railways. The national highway no. 6 connecting Mumbai - Kolkatta passes
through Raipur and it is connected to Vishakhapatnam by national highway no. 47. The average
altitude of project area is 298 m above MSL. Map showing location of project area is presented
as Figure 1.
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Figure 1: location MAP
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1.2.1 Topography
Raipur city is situated in the fertile plains of Chhattisgarh Region. The major constituents of the
soil are silt, clay and sand. The general slope of the land is towards north. Mahanadi is the
primary river of the region which flows to the east of the city. Raipur is situated more or less, on
a flat land of Mahanadi Basin, gently draining towards River Kharun, a tributary of Sheonath
River and Mahanadi. Water supply to the City is from Kharun River, a tributary of Mahanadi that
has been dammed at Mahadeo Ghat.
The southern side of the city has dense forests. The Maikal hills rise on the north-west of Raipur
and on the north, the land rises & merges with Chhota – Nagpur plateau, which extends north-
east across Jharkhand state. On the south of Raipur lies Baster plateau.
1.2.2 Climate
The climate of project area is sub-tropical with three distinct seasons. Temperatures remain
moderate for most of the year. Winter season commences from November and lasts till the end
of January. Summer season starts beginning March and continues till the second week of June.
Monsoon commences from middle of June and remains till the early October.
The post monsoon period between October and November has pleasant climate. The
temperature rises to maximum in May, touching 460C and the mean minimum temperature is
around 90C in December, though the minimum may drop to 5
0C sometimes. May is the hottest
month and December is the coldest.
1.2.3 Rainfall
Rainfall observations indicate that annual rainfall in project area is around 1400 mm. Rains are
predominant during July to mid-September. Relative humidity is higher (> 75%) during monsoon
season. After monsoon season, humidity decreases and during the winter season, air is fairly dry.
South-West is the predominant wind direction. In the post monsoon and winter months, wind
direction is mainly from North-East direction.
From March, trends vary in direction and by April, winds from West and South-West begin to
appear. They are predominant during the period from May to September. Wind is generally calm
(31% in the morning and 33% in the evening) at nights. The city has about 120 calm days.
1.2.4 Geology
Lithological sequence ranging from Archaean to Recent is available in Chhattisgarh. Central India
Shear trending E-divides the State into two parts, Satpura Province in north and Bastar Province
in south.
Satpura Province comprises granite gneisses and metamorphics, ,mineral Resources
Department, Government of Chhattisgarh, India Gondwana sequence, Deccan trap, etc. Bastar
Province comprises Archaean gneissic complex, Bengpals, Bailadila Group, Sonakhan Group,
Chhattisgarh, Indravati Group, etc.
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1.2.5 Seismicity
The project area falls in seismic zone – II
as per the BIS (1893, Part-1, 2002)
category of seismic zoning map of India.
The seismic zoning map showing the
location of Raipur city is displayed as
Figure 2.
1.3 The Need for Project
Raipur has already attained the status of
principal education center of higher
learning. Engineering, Technical Training
Course, Indira Gandhi Agricultural
University and Ravi Shankar University
are some of the higher order education
centers that have already come up in the
city. These institutions together with
organizations like research and
development let Raipur a status of education cum research center of the region.
The major issue of Raipur’s future growth pertains to the growth of the city as the State Capital.
The state government is in the process of establishing the capitol functions in a green-field area
and its integration with Raipur, the primate City of the state. The State Government has initiated
activities on an area of about 1000 hectares near village Kotarabhata, Kuhera and Rakhi in
Mandir Hansad. The New Capital Township is envisaged to develop as a satellite town of Raipur.
Apart from the capital functions, Raipur’s regional primacy as a commercial, industrial and
educational centre needs to be addressed from a future perspective of the regional
development. The foremost issue of urban growth in Raipur pertains to its growth as the State
Capital with appropriate City cynosures.
The population growth experienced so far is expected to continue strongly over the next couple
of decades adding more pressure to the already grossly inadequate infrastructure. If no action is
taken, this is likely to result in contamination of existing surface and underground sources of
water supply for the urban population of Raipur city. For these reasons, it is imperative that an
efficient and effective sewage collection, treatment and disposal system complimented by a
good storm water drainage system be quickly installed to allow Raipur to meet the health and
sanitation needs of the population and to prevent the lack of infrastructure from hampering
economic growth.
The Sewerage, Storm Drainage and Lake Protection Work is therefore an integral part of a series
of major initiatives planned and taken by RMC to provide Raipur city with the basic
infrastructure befitting that of a Capital city. Whilst the TOR calls for the preparation of DPR for
sewerage, surface storm water drainage and lake protection works, it must be stressed that the
sewerage and drainage issues/problems cannot be adequately and effectively addressed until
and unless solid waste handling and management together with institutional strengthening are
concurrently addressed. Only then can the full benefit of the proposed works be realized. This is
because:
Figure – 2: Seismic zoning map
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(a) There is clear evidence that throughout the city raw sewage is finding its way directly into
drainage channels and polluting the lakes all over the city. This has direct detrimental health
impact on the urban poor and weaker sections of population living in the slum areas in the
city.
(b) RMC is solely responsible for proper operation and management of the sewerage, drainage
and solid waste handling systems.
1.3.1 Existing Scenario on Sanitation
There is no centralized sewerage system in the city. Wastewater from houses finds its way into
the open drains and ultimately discharges into Kharun River. This is causing water pollution in
the river and overall hygienic condition of the city is getting worse. The Public Health
Engineering Department of the then unified state had prepared a sewerage scheme in year 1976
for the city to serve up to year 2012 (30 years from year 1982). The scheme slated for full
commissioning by year 1982 has been partially implemented and details are given hereunder.
• A sewerage system was implemented in 1992 and it covers about 25% area (27 wards out of
57 wards) and administered by the Municipal Corporation of Raipur.
• The system consisted collector lines, five pumping stations and a sewerage treatment plant.
Subsequently it was handed over to Raipur Municipal Corporation.
• For sometime mainlines collected sewerage from open drains and five APS were operated
but with high electricity dues, power supply to APS was withdrawn.
• The sewerage generated in the city is around 60 MLD.
• As the scheme is not completed, the wastewater generated in the city does not get any
secondary treatment.
• Even the surface drainage system is not fully present in the city. The drains which are
present; carry the sewage into the water bodies present in the locality or into the nallahs
/canals which drains the effluent into the river Kharun north of the city.
• The areas at present, which are not served by sewerage system, include old city area served
by conservancy system/individual septic tank. Some areas are having their own community
septic tanks with their effluent discharging in to the open sullage drain ultimately joining the
natural drainage.
• At present the total sewer length in Raipur city is about 55.97 km where as the extent of road
length is about 970 km.
• Areas having sewer lines are Gudhiyari in Netaji kanhailal Bajari Ward, Ramana Mandir Area,
Shankar Nagar area in Shankar nagar and Gurugovind Singh wards, Irrigation colony and
Indravathi colonies in Bhahadur Shasthri Ward, main roads in Bhagavathi Charan Shukla
ward, Shalendra Nagar main road in Aravind Dixit ward, main roads in Sadar Bazar ward,
Swamy Vivekananda Ward and Babu Gagjeevan Ram Wards.
• Sewerage Project conceived by Public Health Engineering Department envisaged
construction of 5 pumping stations at (1) Tikarapara (2) Khokhopara (3) Khamatari (4)
Birgaon (5) Daladal Siwani. These five pumping stations have already been constructed.
• The project also provided for construction of 7 oxidation ponds, 4 at Rawabhata and 3 at
Daladalseoni. All these seven oxidation ponds have been completed and these are to be
inadequate for the growing population in and around the city.
The details of existing Trunk, Lateral, sub laterals and Rising main are given below:
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Trunk Sewers (RCC NP-2 Pipes)
S.No. Dia Length
1. 1000mm 4715M
2. 1100mm 495M
3. 1200mm 3370M
TOTAL 8580M
Lateral Sewers (RCC NP-2 Pipes)
S.No. Dia Length
1. 300mm 3020m
2. 350mm 1120m
3. 400 mm 1077m
4. 450 mm 2465m
5. 500 mm 1689m
6. 600 mm 2085m
7. 700 mm 8310m
8. 800 mm 4200m
9. 900 mm 1700m
TOTAL 25666m
Sub Lateral Sewers (SW Pipes)
S.No. Dia Length
1. 150 mm 11146m
2. 200 mm 11115m
3. 250 mm 5520m
TOTAL 27781 M
Railway Crossing detailed
S.No. Dia Rly Gauge Location of Crossing
1. 1200mm B.G. Raipur-Waltare at Gudiyari
2. 1200mm B.G. Raipur-Howra at Culvert No. 381
3. 1200mm B.G. Raipur Sarona Byepass line near Bilaspur Road Bridge
4. 1000mm B.G. Raipur Waltare at Bridge No. 9
5. 900mm N.G. Raipur Dhamtari Near New-Shantinagar
6. 800mm N.G. Raipur Dhamtari at Phafadih.
7. 800mm N.G. Raipur Dhamtari at Gudiyari Bridge No. 3
There are 3 intermediate pumping stations for lifting the sewage from a low level and pumping
to the gravity man hole and 2 Main pumping stations, pumping sewage to oxidation ponds. The
details and current status of these 5 sewage pumping stations and two oxidation ponds is
presented in the following sections.
1.3.1.1 Khamtarai Sewage Pumping Staion
The salient features of Sewage Pumping Station at Khamtarai are as given below.
Details Of Civil Works (Khamtarai Pumping Station)
S.N. Description Value
1 Dry Well And Wet Well (Circular) Divided By Partition Wall In
Between.
23m Dia
2 Size Of Switch Room (Constructed Over Dry Well 10 m X 5 m.
3 Depth Of Wet-Well 8.79 M.
4 Capacity Of Wet-Well 469.25 Cum.
5 Floor Of Dry Well Above The Floor Of Wet Well Channel 1m.
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Details Of Civil Works (Khamtarai Pumping Station)
S.N. Description Value
6 Ground Level At Pumping Station 283.24 m
7 Invert Level Of Incoming Sewer Line 278.5 m
8 Dia Of Incoming Sewer Line RCC NP2 Pipe 1200 mm
9 Floor Level Of Dry Well 275.75 m
10 Floor Level Of Wet-Well 274.75m
11 Roof Level Of Wet-Well 283.54m
12 Mezzanine Floor Level 284.74m
Details Of Pump And Machinery (Khamtarai Pumping Station)
S.N. Parameter Description
1 Type Of Pumps Non Clogging
Horizontal Centrifugal
2 Make of motor Crompton
3 No. Of Pumping Sets Installed 3 No.
4 Discharge Of Pumping Sets 2 Nos. 34 MLD
5 C. Head Of Each Pumping Set 16.50m
6 Suction Size Of Pumping Set 18” (450mm)
7 Delivery Size Of Pumping Set 14” (350mm)
8 Discharge Of 1 No. Of Pumping Set 45mld
9 Head Of The Pumping Set 16.50m
10 Suction Size Of Pumping Set 20”(500mm)
11 Delivery Size Of Pumping Set The Pumps Are Flow More Make 16”(400mm)
The Details Of Motor Installed
12 No. Of Motors Installed 3no.
13 Kw (HP) Of Each Of 2 Nos. Of pumps At 960 Rpm Installed 93kw(125 HP)
14 Kw (HP) of 1 No. Motor At 960 RPM 125kw(167 HP)
15 Total Kw (HP) of All 3 Nos. Motors Installed. 311kw(417 HP)
The pump house has a sub station in the premises but due to non payment of electricity charges,
the electricity is not available. The sluice gates at the inlet of pump house remain shut and
therefore, the sewage flow backward upto the storm water drain on the up stream side of
pumping station; where the sewage is bye passed into the storm water drain. There are DG sets
installed to operate the pumps but are not used regularly.
Photograph of Khamtarai Sewage Pumping Station
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Even after shutting of gates at up stream of pumping station, the sewage seeps into the wet
well. This sewage in the wet well is pumped out periodically to the discharge manhole which
carries the sewage to Birgaon Pumping station by gravity.
1.3.1.2 Birgaon Sewage Pumping Staion
The salient features of Sewage Pumping Station at Birgaon are as given below.
Details of Civil Works (Birgaon Pumping Station)
S.N. Parameter Description
1 Dry Well And Wet-Well (Circular) (Divided By A Partition
Well In Between)
23.00m Dia
2 Size of Switch Room over Dry Well 10mx5m
3 Depth of Wet-Well 9.00m
4 Capacity of Wet-Well 484.80 Cum
5 Floor of Dry Well Above The Floor Of Wet-Well Channel 1.00m
6 Ground Level at Pumping Station 281.40m
7 Invert Level of Incoming Sewer Line 276.55m
8 Dia of Incoming Sever Line RCC NP2 Pipes. 1200mm
9 Floor Level of Dry Well 273.70m
10 Floor Level of Wet-Well Near Suction Pipe 272.70m
11 Roof Level of Wet-Well 281.70m
12 Mezzanine Floor Level 281.70m
13 Roof Level of Switch Room 285.95m
Details of Pump and Machinery (Birgaon Pumping Station)
S.N. Parameter Description
1 Type of Pumps Non Clogging Horizontal
Centrifugal
2 No, of Pumping Sets Installed 3 NOS
3 Discharge of 2 Nos Of Pumping Sets (Each) 35 MLD
4 Head of Each Pumping Sets 27.00M
5 Suction Size of Pumping Set 20”(500 MM)
6 Delivery Size of Pumping Set 16” (400MM)
7 Discharge of 1no. Pumping Set. 46.5 MLD
8 Head of The Pumping Set 2700M
9 Suction Size of Pumping Sets (600MM)
10 Delivery Size of Pumping Set (400MM)
11 Make of Pumps Flow More
12 No. of Motors Installed 3 NOS.
13 Kw (HP) of Each Of 2 Nos. of Motors At 960 Rpm Installed 200 KW(268HP)
14 Kw (HP) of 1 No. Motor At 960 Rpm 224 KW(300HP)
15 Total Kw (HP) of All 3 Nos. Motors Installed 625 KW(836HP)
16 Make of Motors Crompton
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Photograph of Birgaon Sewage Pumping Station
Similar to the status of Khamtarai pumping station, Birgaon also face the same problem of
funding because of which it is not being operated regularly. The sluice gates at the inlet of pump
house remain shut and therefore, the sewage is bye passed into the storm water drain. There
are DG sets installed to operate the pumps but are not used regularly and are operated only to
pump the sewage which has seeped into the wet well. The sewage from the pumping station is
supposed to be pumped into the oxidation pond at Rawabhata but it does not appear being
pumped to the oxidation ponds.
1.3.1.3 Tikrapara Sewage Pumping Staion
The salient features of Sewage Pumping Station at Tikrapara have been given below:
Details of Civil Works (Tikrapara Pumping Station)
S.N. Description Value
1 Ground Level 293.65 m
2 Size of Switch Room 11 m X 6 m
3 Floor Level of Switch Room 295.65
4 Size of Dry Well 11 m X 5.8 m
5 Floor Level of Dry Well 287.00 m
6 Discharge Pipe Line CI 700 mm dia
7 Level of CI pipe 291.05 m
8 Dia of Wet Well 12.00 m
9 Channel Level of Wet Well 286.00 m
10 Roof Level of wet well 293.95 m
11 Level of partition wall 290.30 m
12 Capacity of wet well 125.25 cum
13 Size of screen chamber 1.70 m X 5.00 m
14 Floor level of screen chamber 289.50 m
15 Dia of inlet RCC pipe 700 mm
16 Inlet level of incoming pipe 289.65 m
17 Overflow level 289.50 m
18 Dia of overflow pipe 700 mm dia RCC
19 Dia of pumping main 500 mm dia CI
20 Capacity of transformer 250 KVA / 11 KV 433 V
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Details Of Pumps and Machinery (Tikrapara Pumping Station)
S.N. Description Value
1 Pump make and numbers Flow meter 3 Nos.
2 Discharge of Pumps 12 MLD per pumps
3 Pump Head 22.00 m
4 Suction size 30 cm
5 Delivery size 30 cm
6 LT motor nos. and make 3 Nos. Crompton
7 HP / KW of motor 90 HP / 67 KW
8 RPM of motor 960 RPM
Photograph of Tikrapara Sewage Pumping Station
1.3.1.4 Khokhopara Sewage Pumping Station
The salient features of Sewage Pumping Station at Khokhopara have been given below:
Details of Civil Works (Khokhopara Pumping Station)
S.N. Description Value
1 Size of Dry Well And Switch Room 11M X6M
2 Size of Well (Semi Circular) 12 M. DIA.
3 Depth Wet Well 6.35
4 Capacity of Wet Well 125.25 CUM
5 Floor of Dry Well Above The Floor of Wet Well Channel 1 M.
6 Ground Level At Pumping Station 242.40M
7 Invert Level At Incoming of Sewer Line 280.00M
8 Dia Of Incoming Sewer Line R.C.C. Np-2 Pipe 700MM
9 Floor Level Of Dry Well 277.35M
10 Floor Level Of Wet Well Near Suction Pipe.
11 Roof Level Of Wet Well 282.70M
12 Mezzanine Floor Level 283.40M
13 Roof Level Of Switch Room 287.65 M
14 Size of Dry Well And Swicth Room 11M X6M
Details Of Pumps and Machinery (Khokhopara Pumping Station)
S.N. Description Value
1 No. of Pumping Sets Installed 3 Nos
2 Discharge of 2 Nos. of Pumping Set 9 MLD. Each
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Details Of Pumps and Machinery (Khokhopara Pumping Station)
S.N. Description Value
3 Head of Each Pumping Set 30 M
4 Suction Size of Pumping Set 12” (300 MM)
5 Delivery Size of Pumping Set 8” (200MM)
6 Discharge of 1 No. Pumping Set 12 MLD.
7 Head of Pumping Set 30 MM.
8 Suction Size of Pumping Set 12”(300MM)
9 Delivery Size of Pumping Set 8(200MM)
10 No. of Motors Installed 3 NOS
11 Kw (HP) of Each 2 Nos. of Motors At 960 RPM Installed. 82 KW(110 HP)
12 Kw(HP) of 1 No. Motor At 960 RPM 93 KW(115 HP)
13 Total Kw(HP)of All 3 Motors Installed 275 Kw 34.5 HP
14 Make of Motors Crompton
Khokhopara pumping station is not in operation as electricity supply is not available due to non
payment of electricity charges and DG sets are also not installed in this pumping station. The
sluice gates at the inlet of pump house remain shut and sewage is bye passed into the storm
water drain on up stream side. The pumping station is non functional.
Photograph of Khokhopara Sewage Pumping Station
1.3.1.5 Daldal Seoni Sewage Pumping Station
The salient features of Sewage Pumping Station at Khokhopara have been given below:
Details of Civil Works (Daldal Seoni Pumping Station)
S.N. Parameter Description
1 Dry Well and Switch Room 14 m Dia
Floor Level of Dry Well 263.35 m
2 Roof Level of Switch Room 280.10 m
3 Size of Wet well 23.0 m dia
Depth of wet well 9.45 m
4 Capacity of Wet-Well 4.17 Cum
5 Floor level of Dry Well near suction 264.96 m
6 Roof Level 274..80 m
7 Dia of incoming sewer 1000 mm
8 Invert Level of incoming sewer 269.50 m
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Details of Pump and Machinery (Daldal Seoni Main Pumping Station)
S.N. Parameter Description
1 No. of pump Installed 3 Nos.
2 Discharge of 2 pumps of same configuration 30 MLD / each pump
3 Discharge of 1 pumps of different configuration 40 MLD/each pump
4 Head 15.50m
5 Dia of suction pipe 350mm dia
6 Dia. Of Delivery pipes 400 mm dia
7 Motor make Crompton
8 No. of motor Installed 3 Nos.
9 KW/HP of motor of 2 pumps of same configuration 82 KW/110HP(Each)
10 KW/HP of motor of 1 pumps of different configuration 110 KW/127 H.P.
11 Dia of C.I. Pumping main 750 mm
12 Length of Pumping main 321 mts.
13 Diesel Generator Set Rusian Model
14 (i) Year of Installation 1994
15 (ii) No of D.G. Set 1. No. of 160 KVA
This pumping station is comparatively in running condition as compared to other pumping
stations in Raipur. The pump house has a sub station in the premises but due to non payment of
electricity charges, the electricity is not available. The sluice gates at the inlet of pump house
generally remain shut and the sewage is bye passed into the storm water drain near the
pumping station premises. DG sets have been installed to operate the pumps and are used
periodically when sewage is taken in the wet well. The sewage is then pumped into the
Oxidation ponds in the premises for natural treatment.
Photograph of Daldal Seoni Sewage Pumping Station
1.3.1.6 Daldal Seoni Oxidation Pond
The salient features of Oxidation Pond at Daldal Seoni have been given below:
Details of Oxidation at Daldal Seoni
S.N. Parameter Description
1 Nos. of Ponds 3
2 Size 1 No. 80 m X 240 m
2 Nos. 80 m X 300 m
3 Depth 1.27 m
4 Incoming pumping main CI 750 mm dia
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Oxidation pond at Daldal Seoni is also not being used for the treatment of sewage. The ponds
are seems to be abandoned and only sometime sewage is pumped into it as it was apparent
during survey at the site. Grass and weeds had grown in the ponds as shown in the picture.
Ponds are in poor shape as not much of maintenance work has been done to keep it in running
condition.
Photograph of Daldal Seoni Oxidation Pond
1.3.1.7 Rawa Bhata Oxidation Pond
The salient features of Oxidation Pond at Rawa Bhata have been given below:
Details of Oxidation at Rawa Bhata
S.N. Parameter Description
1 Nos. of Ponds 6
2 Size of each pond 320 m X 110 m
3 Depth 1.3 m
Oxidation pond at Rawabhata is abandoned and not being used for the treatment of sewage. No
sewage is pumped in the oxidation ponds. One of the ponds has become site for RCC pipe
manufacturing as it could be seen in the following photographs. Earlier when sewage was
pumped into it, the local residents used to object because of the foul smell it used to spread.
Due to not using the oxidation ponds, grass and weeds have grown in the ponds as shown in the
picture. Ponds are in poor shape and appears to be something like open ground.
Photograph of Rawabhata Oxidation Pond
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1.4 Objectives of Raipur Municipal Corporation
The objective of the consultancy is to provide project management support to RMC, which
includes management, survey, design, detailed engineering services and procurement and also
supervisory support for sewerage, storm water drainage and lake protection works. The
assignment would be executed in two partially overlapping phases described in the following
sections.
Phase I: Comprise surveys, investigations, and consultancy activities leading to preparation of
detailed project reports, bid documents and further procurement support. It includes all
necessary investigation including but not limited to topographic and alignment surveys, geo-
technical investigations, pavement and sub-soil investigation, finalization of design concepts of
sewerage infrastructure (gravity based), preparation of detailed designs for sewerage, drainage
and lake protection works, estimation of costs, finalization of alignment and routing of sewers,
preparation of tender documents. Comprises of tendering, answering tender's clarifications,
tender evaluation and recommendation and financial closure, documentation, etc.
Phase II: Supervisory supports till commissioning of the projects and also arranging and getting
financial support from JNNURM and other agencies if required.
The real benefit resulting from the completion of this project will be the improved health and
welfare of the communities in Raipur City through better sanitary conditions, hygienic
surroundings and better water quality in Lakes and Nallahs crossing the City.
1.4.1 The Consultants
As part of this endeavor, RMC invited tender for Project Management Consultancy Services for
Preparation of DPR for Sewerage, Storm, Surface Water Drainage and Lake protection Works for
Raipur city. RMC has retained Meinhardt (Singapore) Pte Ltd (MSPL) to provide the above
services. This project is, therefore, an integral part of a series of major initiatives planned by
RMC to provide Raipur city with the basic infrastructure.
1.5 Scope of Consultancy Services
The scope covers consultancy service for design, procurement support and project management
services. Total length of sewers/drains to be laid is around 1000 km (approx.) of primary and
secondary sewers. The Project envisages Sewerage, Surface, Storm Water Drains & Lake
Protection covering an area of 142 Sq. km., spread over the whole Raipur Municipal Council
area. Apart from the above, pumping stations, if required and sewage treatment plants are also
proposed.
In addition, the scope of services would also include stake holders consultation, the preparation
of report for Environmental Clearances and such other functions as are required to be
undertaken as would in normal course be associated with PMC. Services to be provided by the
Consultant are listed below.
1.5.1 General Scope of Services
The PMC would provide its services in accordance with Good Industry Practice. For this purpose
the PMC shall undertake, inter-alia, the following activities and where appropriate make suitable
suggestions:
(a) The PMC shall coordinate the activities of all parties including Client offices to effectively
deliver their services, i.e. preparation of various documents required in getting project and
various other expenses sanctioned and disbursed under JNNURM/other agencies.
(b) The PMC shall have interface with the RMC for communicating the project progress and
assist RMC in resolving issues.
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1.5.2 Specific Services
The assignment comprises project development and management support for Municipal
Corporation Raipur, which inter-alia includes preparation of feasibility report, survey,
Preparation of Detailed Project Report, design, detailed engineering services, technical approval
and procurement support and also management, management information system and
supervisory support for the storm water drainage, sewerage & repair/construction of road, etc,
due to laying of sewer and other lines and lake protection of entire Raipur Municipal
Corporation areas. All these have to be done taking into consideration present/proposed master
plan, future development in development plan and in investment areas, etc.
The Consultant shall also have to act for;
• Restoration of lakes in Raipur
• Proposals for Cleaning of the lakes (removal of water hyacinth, bio-remediation of the lake,
etc.)
• Prevention of pollution of lakes by implementing the scheme for sewage
collection and treatment.
• Prevent unauthorized developments & control developments around the lakes.
• Provision of recreation facilities for the residents of Raipur.
The assignment shall be executed in two phases:
• Phase I : Project Development Phase
• Phase II : Project Management Phase
1.5.2.1 Phase - I: Project Development Phase
i. Study the existing settlements, demographic pattern, growth and development trends of
the project area and existing infrastructure related to the project which can be
incorporated in the project with or without re -engineering.
ii. Carry out any Topological and Alignment surveys as needed; using GIS technology, carryout
hydraulic, geotechnical and soil investigations, traffic surveys, etc, needed.
iii. Map the existing storm water drains, cross drains with their parameters such as type, area,
length, width, flow direction etc, as may be relevant and necessary for the designs of the
projects.
iv. Prepare a preliminary project report describing different components and parameters,
along with a rough estimate of cost for each of the three projects.
v. Make presentation before the authorities of the Municipal Corporation Raipur, the State
Government and any other authorities if required.
vi. Modify the preliminary project reports if required.
vii. Prepare detailed project reports for each of the three projects for financial assistance
under the mission or any other financing institution.
viii. Assist in the projects appraised from the financing institutions, modify the DPRs if required,
and make presentation.
ix. Design appropriate facilities and components of the projects including the connecting and
effluent systems.
x. Prepare detailed cost estimates - both capital and Operation & maintenance (O&M) and
suggest and assist in recovery of O&M cost & also to implement reforms related with these
activities.
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xi. Prepare detailed economic analysis of the alternatives chosen.
xii. Prepare detailed project report and working drawings.
xiii. Prepare detailed Operation and Maintenance Plans for Strom water drainage system,
sewerage and lake protection.
xiv. Prepare feasible contract packages, based on contractors' capacity, availability of materials,
land availability, sequencing of work etc. Identify appropriate procurement procedures in
accordance with the CG Works Department Manual.
xv. Prepare pre implementation Environment Impact Assessment.
xvi. Obtain Environmental Clearance from appropriate authorities if required.
xvii. Prepare Quality Assurance and Management Plan to be followed during implementation
stipulating the quality assurance procedures, frequency and sampling of testing, etc.
xviii. Prepare Customer connection program either managed by the Municipal Corporation
Raipur or a Private Sector Operator.
xix. Assist Municipal Corporation Raipur in stakeholder consultation process in resolving the
administrative, technical, social and environmental issues including obtaining various
permissions and approvals from different agencies.
xx. Prepare construction supervision manuals stipulating the construction supervision and
contract management framework to be followed during implementation. Set out a
mechanism in consultation with Municipal Corporation Raipur for assessment of work of
Contractor.
xxi. Amend/correct the designs and working drawings, estimates, cost analysis as and when
required as per the site conditions and implementation needs.
xxii. Based on the packages identified and approved by Commissioner, Municipal Corporation
Raipur, prepare Bid Documents, Bill of Quantities (BoQs) and construction drawings.
xxiii. Manage the procurement process including prequalification of contractors, Organizing pre-
bid conferences, help Municipal Corporation Raipur in answering queries and draft
addenda to the bid documents, if required, assist in evaluation of bid and recommend to
Municipal Corporation Raipur on award of works. Preparation and issue of letters of intent
and award etc. issue of letter of commencement, etc.
1.5.2.2 Phase - II: Project Management Phase / Supervision Phase
The Consultant's Design staff shall make visits to the works at different stages of construction, to
review the works while the Construction supervision staff of the consultant shall supervise and
monitor all aspect of the works at all Stages of construction as agreed with the Commissioner,
Municipal Corporation Raipur.
I. Review the quality assurance plan and implementation plan submitted by the Contractors.
II. Review work plans, activity schedules and progress reports submitted by Contractors.
III. Review drawings, review Contractors' proposals for modifications to the design, review of
modifications to construction drawings made necessary by changes in physical conditions at
site.
IV. Interpret the requirements of the Contract and make decisions regarding performance of
the Contractors. Advise in a timely manner on all matters relating to the quality and
performance standards of the Project. When requested by Municipal Corporation Raipur,
provide specialist technical advice in respect of issues related to dispute resolution.
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V. Based on the contract management framework agreed with Municipal Corporation, monitor
works carried out by Contractors compliance with the construction supervision and quality
assurance procedures stipulated in the manuals. Constantly assess, monitor and report the
achievement of timelines and targets as per Contracts Assist Municipal Corporation Raipur
in Contract Administration, Construction Supervision and monitoring and in certification of
works.
VI. Review the manpower and equipment deployed by the Contractors. Designate tests on
materials and/or equipment used by the Contractors. Review, recommend approval or
rejection of drawings, samples, and other submissions of the Contractors to determine
compliance with the requirements of the Contract.
VII. Report the quality aspects to Municipal Corporation Raipur based on various tests carried
out by Contractors including hydraulic tests and leak tests or any additional tests deemed
necessary by the Consultant in consultation with Commissioner, Municipal Corporation
Raipur. Assess the quality of materials, workmanship and equipment. Identify and report
work which fails to comply with the specifications and requirements of the Contracts.
Whenever considered necessary or advisable to ensure correction of defective work, the
Consultant may require inspection or testing of such work, whether or not such work be
then fabricated, installed, or completed.
a) Ensure that all design and construction works fully comply with all Applicable Laws.
b) Test all materials supplied by the Contractor such as SW/RCC/GRP pipes, cement, steel,
bricks, concrete, coarse aggregates, sand, soling materials and all other materials
connected with the works, etc. Test and inspect all electrical mechanical and electronic
items.
c) To certify measurements of all the works executed in respect of all the contract packages.
d) Assess the validity of any adjustments, cost over runs to the nature and value of works of
the Contractors and to assist the Municipal Corporation Raipur in arriving at adjustments
to the Contract as permissible by law in this respect, acceptable to both the Municipal
Corporation Raipur and the Contractors.
e) Supervise, on site testing, commissioning procedures and assist Municipal Corporation
Raipur in issuing certificate of satisfactory completion of works.
f) Assist Municipal Corporation Raipur in any social or environmental audits taken up during
or after completion of the Projects Prepare and submit GIS based completion Drawing
and Report showing details such as manholes, pumping station, treatment plant,
households connections etc. Also assist the corporation in getting entire project cost
sanctioned from JNNURM, State Government, Financial Institution if required at any
point of time modify, bifurcate upgrade the DPR, etc. as per the requirements.
g) Set out a mechanism for satisfactory hand over of the facilities to Municipal Corporation
Raipur, The Consultant shall monitor the transfer of the facilities including any necessary
testing and inspections and ensure that the facilities transferred are as per the provisions
of Contract.
h) Prepare and submit to Municipal Corporation Raipur, Monthly/Periodically Progress
Reports (as and when required) including the following :-
1. Progress review and monitoring.
2. Report on tests.
3. Report on notices issued.
4. Issues if any, with regard to works along with the details of the action taken for the
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resolution of the same.
5. Photographic record of the progress of works at periodical intervals.
6. Periodical progress reports to the respective project monitoring and steering
committees including the funding agency.
i) Assist Municipal Corporation Raipur in i) reporting to the higher authorities on the
progress, and ii) in collecting / providing information to follow-up on the component's
monitoring indicators.
For the purpose of fulfilling the objectives of the Municipal Corporation Raipur the Consultant
Designer shall undertake, inter-alia, the following activities and where appropriate make suitable
suggestions.
(a) The Consultant shall coordinate the activities of all parties including Municipal Corporation
Raipur offices to effectively deliver their services.
(b) The Consultant shall use suitable commercially available project management software to
facilitate overall contract administration, progress monitoring and reporting and shall train
the Municipal Corporation Raipur staff in hands-on use of such software.
(c) Consultant shall constantly assess, monitor and review the work of the Contractors as per the
Contracts. The Consultant shall attend regular meetings ("Project Review Meetings" or
"PRMs") with Municipal Corporation Raipur and Contractors, to be held at least once a
month during the Construction Period to report on progress and quality of work performed
by the Contractors and to discuss problems or other pertinent matters relating to the work.
The Consultant shall take notes at the meetings and produce the PRM minutes. The PRM
minutes should highlight all elements of the project on which there are delays or other
problems with summary of actions taken or to be taken to resolve these with clear
allocation of responsibility for each.
1.6 Review of Past Reports/Studies
The past studies and available reports thereof, were reviewed to understand the proposals in
respect of sewerage system. A detailed review is presented in Chapter-2 of Inception Report.
RMC has envisioned the necessity of providing basic sewerage infrastructure to the population
of city at different times, however, none of the schemes has been implementation to a level fit
for a Capital city. All proposals highlight the urgent need for provision of sewerage system for
different horizons. Hence it is very appropriate to make out a detailed design of sewerage
system for a period of 30 years considering future growth potential of the city.
1.7 Format of the Report
This Detailed Project Report (DPR)-Sewerage Volume –I, is being prepared as per the ToR. This
report contains fifteen chapters and an Executive Summary.
Chapter-1 is on Introduction. Chapter-2 describes briefly the planning aspects. Chapter-3 is on
population projections for the project. Chapter-4 is on sewage generation. Chapter-5 is on
design considerations for the sewerage components. Chapter-6 is on design criteria. Chapter-7 is
on design of sewers. Chapter-8 is on design of sewage pumping stations. Design of sewage
treatment plant is presented in Chapter-9. Chapter-10 presents the aspects of Environmental
Impacts for this project. Chapetr-11 is on operation and maintenance of sewerage system.
Chapter-12 highlights the application of Project Management. Cost estimates for the complete
system are presented in Chapter-13. Chapter-14 is on Financial Analysis. Conclusions and
Recommendations are given in Chapter-15. Annexures are enclosed at the end of this report.
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The complete set of DPR is divided into Ten (10) Volumes.
Volume – I Detailed Project Report (Technical) – Sewerage
Volume – II Hydraulic Design of Gravity Sewers
Volume – III Hydraulic Design of SPS and STPs
Volume – IV Cost Estimates
Volume – V Bill of Quantities
Volume – VI Sewer Layouts
Volume – VII Survey Layouts
Volume – VIII Bedding Design for Gravity Sewers
Volume – IX Environmental Impact Assessment Report
Volume – X L- Sections of Gravity Sewers
***
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Planning of Sewerage System 2222
2.0 Planning of Sewerage System
2.1 Objective of Planning
It is widely believed that improvements in the sanitation sector can play a major role in
improving lives of the people. It is also expected that the sewerage and drainage to have an
integrated approach when planning for a modern city. Without integration, there would be
duplication of efforts which leads to confusion. For example, when people are encouraged to
adopt pipe based sewerage system, low cost or individual disposal should not be encouraged in
that area. The planning of a new sewerage system is achieved by exhaustive public consultation,
in order to enable the communities to establish a clear picture of their responsibilities in use of
the future services.
The development objectives of this project are:
a) Better living conditions for the urban and peri-urban people of Raipur by improved access of
the population to safe wastewater disposal.
b) Improved environmental sanitation as a bye product of improved access to sewerage
system, reduced incidence of water and wastewater related diseases and mortality rate
resulting in improved health and personal hygiene of people.
2.2 Specific Short-Term and Long-Term Planning
Sewerage infrastructure requirements are planned on the basis of Master Land Use Plan of the
area. The potential development proposed over a period of atleast two to three decades is the
basis of planning in such plans. Normally the proposals under such plans are divided in to two
categories, short-term and long-term planning. Availability of funds also plays important role in
defining the term of services required.
Short-term planning: It is basically adopted where the services need extension or augmentation
in immediate stage for a period of about five years or so. The type of components considered
under short-term planning are oriented towards solving the area specific concerns of the
communities.
Long-term planning: This aspect of planning is normally called as Master Plan in respect of the
services envisaged. The period of plan is normally 25 to 30 years considering the potential of
development in the proposed land use. The long-term plans normally spell about the
requirement of infrastructure at different phases of time. The requirement and allocation of
funds is also spelt out with expenditure allotment on different aspects of the services, like,
expansion of capacity, construction of new infrastructure, services to new areas developing on
fringe of the master plan. The master plan in respect of Raipur city would envisage at;
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a) Providing safe sewage disposal facilities for about 10.15 Lacs (immediate) and 26.94 Lacs
(ultimate) population living in 142 sq. km. urban areas of Raipur by way of approximately
1032 km of length of sewer lines and 3 number of sewage treatment plants.
b) Improved health of the population and improved on-land disposal of treated wastewater, as
such improved access of the population to increased agriculture, productive employment/
improved economic resources and hence overall better economic conditions of the
beneficiary population.
2.3 Expected Outputs
A completed, operational, properly managed sewerage system for the inhabitants of Raipur
urban area(s). There are three typical components which are measurable in respect to the
communities served. These components are the (i) technical, (ii) socio-economic, and (iii)
environmental.
2.3.1 Technical
A technically sound, hydraulically self efficient and structurally safe sewage treatment plant/s
scheme complemented with sewerage conveyance system, pumping facilities for the urban
areas of Raipur. The scheme is designed to cater to the sewage generation production capacity
for the designed year 2042 for a projected population at 26.94 Lacs. The system flow shall be by
gravity in most of the reaches within the area, some pumping stations where unavoidable and
up to the treatment plant and for onward disposal of the treated effluent to river / agriculture
fields. The effluent shall qualitatively meet the prescribed CPHEEO/ CPCB standards for the
industrial reuse and /or inland water bodies. The sludge produced out of the STP/s shall be
professionally managed, prior to its disposal.
In design of sewerage system, the measurable technical outputs are as under;
� Design guidelines
� Detailed hydraulic design of network
� Computations related to adequacy checks
� Hydraulic profile of works
� Longitudinal section of sewers
� Construction drawings
� Technical specification of works
2.3.2 Socio-economic
Many municipal projects are conceived with a notion to serve the society as a whole. On the
social side, studies conducted across the world, to analyze the social impact of providing
sewerage system to the population in the surrounding reveals improvement in the quality of the
life of people. Many governments have started to think the investment in sanitation services as
“social capital” as it recognizes the welfare of local communities. The implementing agencies
have recognized the involvement of communities in operation and maintenance of the system as
a complementary relationship between agencies and self organized citizen groups. The social
objective normally envisaged is;
� To connect or extend sewerage systems to meet the required demand of sanitation in
existing area and potential developing area.
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A significant reduction in risk to human health for the residents of the surrounding
communities as a result of improved facility use has been documented. Improvement in the
economic conditions and social well being of people is also a social benefit. Socio-
economically the project aims at;
� A more cohesive, environmentally sanitized and population practicing safe personal hygiene
and better waste management methods leading to change in attitude of people towards
overall living conditions.
� Improvement in overall economic status of the beneficiary population by way of improved
agriculture, reduction in health related expenses and minimizing the losses otherwise
incurred on account of “Loss in Monetary Earning/Salary” because of loss of earning days
and also Medical bills incurred on medical care per family on recurrent basis.
2.3.3 Environmental
Untreated sewage carries a dangerous cargo of infectious bacteria, viruses, parasites and
chemicals. On the environmental side, the impact of not having a sewerage system can be some
or all of the below mentioned;
� Insufficient toilet units in a large number of houses.
� Residents and mostly women excrete in open areas and as a result they are subjected to
embarrassment. Men and children also excrete in open area which causes foul odor.
� Residents throw sewage and used water in lakes and drains, which pollutes the water used
for irrigation.
� The current sewage system is not suitable since tanks may pollute underground water.
A significant reduction in impacts on the natural environment as a result of providing sewerage
system has been documented. Some of the points are;
� Reduction in open defecation, leading to less harmful impacts on the environment.
� Improvement in the air quality.
� Improvement of the health conditions of the people of surrounding communities.
***
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Population Projection 3333
3.0 Population Projection
3.1 General
The first settlement of Raipur city was the Raipura village, near Mahadev Ghat on the bank of
Kharun River. The second one came up close by at Purani Basti and the third settlement
emerged as Budhapara along the Budha talab, which served as the major source of water for the
people. Contrary to the present position, during the beginning of the 9th
century the town has
considerably expanded more towards south and west, and extended right up to Mahadev Ghat.
In 1867 the Municipality was created in Raipur. The Municipality was reconstituted in 1883, 1903
and 1925-26 under the Central Provinces and Berar Municipality act of 1922. In 1909, Gole Bazar
was made by Colonel Twyford. In 1951, the total area of Raipur Municipal Council was 8.0 square
miles occupied by 16,823 residential houses. The area increased to 9.72 square miles or 25.17
square kilometers, while the number of occupied houses arose to 25,785 in 1961.
Raipur was the seventh largest town of the Central Provinces with a population of 24948 in
1881, the number went up to 32114 in 1901 and now after hundred years the population is
touching around 7.0 lakhs.
Raipur is the largest city in the state with a population of 6,70,042 souls as per year 2001 census.
The census data on decadal population since year 1881 is presented in Table 3.1 below.
Table 3.1: Decadal Population Data for Raipur City
Sr. No. Census year Population, Souls
1 1881 24,948
2 1891 23,759
3 1901 32,114
4 1911 35,335
5 1921 38,341
6 1931 45,390
7 1941 63,465
8 1951 80,804
9 1961 1,39,792
10 1971 1,74,518
11 1981 3,38,000
12 1991 4,61,000
13 2001 6,70,042
Source: Sewerage Report 1976 & CDP for Raipur City
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3.2 City Development Plan (CDP) of Raipur City
The Population that has been taken for CDP pertains to population of Municipal Corporation
area as per census 2001. In the year 2003, 26 villages were brought under Raipur Municipal
Corporation (RMC). These villages had a population of 88139 as per 2001 census and were
added as 16 Wards under RMC. The growth rate for projecting the population of these villages
for the year 2003 has been taken at 2.01% (The growth rate for rural population in Madhya
Pradesh between 1991-2001). Considering that population the projection has been done for
2005 to 2021. The average annual growth rates of Raipur city between year 1981 and year 2011
are given in Table 3.2.
Table 3.2: The Average Annual Growth Rates of Raipur city
Sr. No. Year Population Average Annual Growth
Rate (%)
1 1981 3,38,000 5.07
2 1991 4,61,000 3.15
3 2001 6,70,042 3.81
4 2005 (estimated) 8,66,545 3.48
5 2011 (projected) 10,64,045 3.48
Note: Population projection has been done using Compound Growth Rate Method
Source: CDP for Raipur City, Section 2.1, Page15.
The city is witnessing rapid growth since it has assumed the role of Capital City. The growth rate
is significantly above the average national growth rate in urban areas.
The rates of growth of population experienced by Raipur Urban Agglomeration during 1991 and
2001 will continue in future though at a lesser rate. The projections given in CDP indicate that
the Raipur Municipal Corporation would house a population of 10.64 lakhs in 2011 and 14.98
lakhs in 2021. The detail is shown in Table 3.3.
Table 3.3: The CDP Proposed Decadal Growth Rate
Year Decade Growth Rate, % Population
2001 1991-2001 37.9 67,0042
2011 2001-2011 34.8 10,64,045
2021 2011-2021 34.8 14,98,216
Source: CDP for Raipur City, Section 2.1.1, Page18.
3.3 Consultant’s Projection for Project
The total population in RMC as per year 2001 census was 6,70,042 souls. The population
projections from various available reports and documents were analysed and compared. The
population projection calculations were carried out using the following methods:
• Incremental Increase Method
• Geometric increase Method
• Arithmetic Increase Method
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• Decreasing Rate of Growth Method
The projected population has been compared with the projections as per the DPR of Raipur
Augmentation Water Supply Scheme (DPR-RAWS) and the City Development Plan (CDP) of
Raipur city.
The full report including calculations and recommendations, as submitted to Raipur Municipal
Corporation is presented in Annexure-2. The recommendations mentioned in the population
projection report are reproduced below.
1. Since the project is envisaged for commissioning by year 2012, the beginning population for
project is considered for year 2012. Therefore, the 30 year design period as per CPHEEO is
taken as year 2042.
2. Year 2027 is taken as intermediate design period (i.e. 15 years from year 2012).
3. The DPE-AWS is prepared for ultimate population of 21,35,960 souls in year 2038
mentioning @ 3.48% per annum growth rate after year 2023. However, the population
projected @ 3.48% per annum in consideration with base year 2008 for design of water
supply system.
4. It is prudent to assume the growth rate of 3.48% for the extended period beyond year 2038
and upto year 2042 which is ultimate year for sewage project.
5. The projected population beyond year 2021 is based on uniform growth rate of 3.48% per
annum, which is in line with water supply DPR-AWS.
6. The intermediate stage (year 2027) and ultimate stage (year 2042) population for the project
is suggested as 19,33,452 souls and 24,49,169 souls, respectively.
3.4 Final Population for Design
The PMU-JNNURM of Government of Chhattisgarh had communicated to include 10% additional
population above the projected population of 24,49,169 souls for year 2042 for the design of
sewerage system.
This adds up to 24.49 Lacs + 2.44 Lacs = 26.94 Lacs.
***
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Sewage Generation 4444
4.0 Sewage Generation
4.1 General
Municipal or sanitary sewers are normally designed to carry the peak residential, commercial
and industrial flow, including the infiltration, where such condition exists. The computation of
design flow is governed by rate of water supply in the project area. The norms for provision of
water supply facilities in urban areas as per CPHEEO /manual is given in Table 4.1.
Table - 4.1: Urban Water Supply Norms
Sr.
No. Classification of Towns / Cities
Recommended Maximum Water
Supply Levels (LPCD) (as per
CPHEEO)
1 Towns provided with piped water supply
but without sewerage system 70
2
Cities provided with piped water supply
where sewerage system is existing or
contemplated
135
3
Metropolitan and mega cities provided
with piped water supply where sewerage
system is existing or contemplated
150
4.2 Water Supply Rate in Project Area
Raipur being a Capital City and having good scope for future development and falls under
category No. 2, of Table 4.1. However, the proposed water supply scheme is being implemented
at 135 litre/capita/day water supply rate. Sewage generation estimate for project is based on
135 litre/capita/day as the water supply rate and 80% of it as sewage generation in accordance
with the CPHEEO guidelines.
4.3 Sewage Quantification - Ward wise
Using 108 lpcd as sewage contribution, the ward wise sewage quantities are given in Table 4.2.
Table – 4.2: Ward Wise Projection of Sewage Generation (MLD) for Raipur
Population Water Requirement (MLD) Sewage Generation (MLD) Ward
No. 2012 2027 2042 2012 2027 2042 2012 2027 2042
1 16038 30561 42583 2.17 4.13 5.75 1.73 3.30 4.60
2 16531 31499 43891 2.23 4.25 5.93 1.79 3.40 4.74
3 16536 31509 43905 2.23 4.25 5.93 1.79 3.40 4.74
4 16441 31328 43653 2.22 4.23 5.89 1.78 3.38 4.71
5 15210 28982 40384 2.05 3.91 5.45 1.64 3.13 4.36
6 13181 25116 34997 1.78 3.39 4.72 1.42 2.71 3.78
7 15745 30002 41805 2.13 4.05 5.64 1.70 3.24 4.51
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Table – 4.2: Ward Wise Projection of Sewage Generation (MLD) for Raipur
Population Water Requirement (MLD) Sewage Generation (MLD) Ward
No. 2012 2027 2042 2012 2027 2042 2012 2027 2042
8 16266 30994 43187 2.20 4.18 5.83 1.76 3.35 4.66
9 15196 28957 40348 2.05 3.91 5.45 1.64 3.13 4.36
10 16230 30925 43092 2.19 4.17 5.82 1.75 3.34 4.65
11 13932 26547 36990 1.88 3.58 4.99 1.50 2.87 3.99
12 15233 29025 40444 2.06 3.92 5.46 1.65 3.13 4.37
13 15030 28640 39908 2.03 3.87 5.39 1.62 3.09 4.31
14 13180 25114 34993 1.78 3.39 4.72 1.42 2.71 3.78
15 15186 28936 40320 2.05 3.91 5.44 1.64 3.13 4.35
16 14070 26809 37356 1.90 3.62 5.04 1.52 2.90 4.03
17 12935 24647 34343 1.75 3.33 4.64 1.40 2.66 3.71
18 15939 30372 42320 2.15 4.10 5.71 1.72 3.28 4.57
19 15524 29581 41219 2.10 3.99 5.56 1.68 3.19 4.45
20 16199 30867 43010 2.19 4.17 5.81 1.75 3.33 4.65
21 12707 24213 33739 1.72 3.27 4.55 1.37 2.62 3.64
22 13451 25631 35715 1.82 3.46 4.82 1.45 2.77 3.86
23 13758 26215 36528 1.86 3.54 4.93 1.49 2.83 3.95
24 13451 25631 35715 1.82 3.46 4.82 1.45 2.77 3.86
25 13847 26386 36767 1.87 3.56 4.96 1.50 2.85 3.97
26 16017 30520 42527 2.16 4.12 5.74 1.73 3.30 4.59
27 14186 27031 37666 1.92 3.65 5.08 1.53 2.92 4.07
28 16635 31698 44168 2.25 4.28 5.96 1.80 3.42 4.77
29 13936 26554 37001 1.88 3.58 5.00 1.51 2.87 4.00
30 12402 23632 32929 1.67 3.19 4.45 1.34 2.55 3.56
31 13728 26159 36450 1.85 3.53 4.92 1.48 2.83 3.94
32 14361 27365 38131 1.94 3.69 5.15 1.55 2.96 4.12
33 13252 25251 35185 1.79 3.41 4.75 1.43 2.73 3.80
34 13870 26429 36827 1.87 3.57 4.97 1.50 2.85 3.98
35 14294 27238 37953 1.93 3.68 5.12 1.54 2.94 4.10
36 14456 27546 38383 1.95 3.72 5.18 1.56 2.98 4.15
37 14648 27911 38891 1.98 3.77 5.25 1.58 3.01 4.20
38 16102 30683 42754 2.17 4.14 5.77 1.74 3.31 4.62
39 12394 23617 32908 1.67 3.19 4.44 1.34 2.55 3.55
40 12668 24139 33636 1.71 3.26 4.54 1.37 2.61 3.63
41 12620 24048 33508 1.70 3.25 4.52 1.36 2.60 3.62
42 16164 30800 42917 2.18 4.16 5.79 1.75 3.33 4.64
43 16390 31231 43518 2.21 4.22 5.87 1.77 3.37 4.70
44 16042 30568 42594 2.17 4.13 5.75 1.73 3.30 4.60
45 13461 25649 35740 1.82 3.46 4.82 1.45 2.77 3.86
46 13552 25823 35981 1.83 3.49 4.86 1.46 2.79 3.89
47 14178 27016 37644 1.91 3.65 5.08 1.53 2.92 4.07
48 16060 30601 42640 2.17 4.13 5.76 1.73 3.30 4.61
49 15013 28607 39862 2.03 3.86 5.38 1.62 3.09 4.31
50 12671 24145 33643 1.71 3.26 4.54 1.37 2.61 3.63
51 13901 26488 36909 1.88 3.58 4.98 1.50 2.86 3.99
52 14865 28324 39467 2.01 3.82 5.33 1.61 3.06 4.26
53 16260 30984 43173 2.20 4.18 5.83 1.76 3.35 4.66
54 12995 24762 34503 1.75 3.34 4.66 1.40 2.67 3.73
55 15473 29484 41084 2.09 3.98 5.55 1.67 3.18 4.44
56 13730 26162 36454 1.85 3.53 4.92 1.48 2.83 3.94
57 12624 24055 33519 1.70 3.25 4.53 1.36 2.60 3.62
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Table – 4.2: Ward Wise Projection of Sewage Generation (MLD) for Raipur
Population Water Requirement (MLD) Sewage Generation (MLD) Ward
No. 2012 2027 2042 2012 2027 2042 2012 2027 2042
58 12891 24563 34226 1.74 3.32 4.62 1.39 2.65 3.70
59 12782 24356 33938 1.73 3.29 4.58 1.38 2.63 3.67
60 13291 25325 35288 1.79 3.42 4.76 1.44 2.74 3.81
61 13873 26435 36834 1.87 3.57 4.97 1.50 2.85 3.98
62 14462 27557 38398 1.95 3.72 5.18 1.56 2.98 4.15
63 16396 31242 43532 2.21 4.22 5.88 1.77 3.37 4.70
64 15320 29191 40675 2.07 3.94 5.49 1.65 3.15 4.39
65 12801 24392 33988 1.73 3.29 4.59 1.38 2.63 3.67
66 13295 25333 35299 1.79 3.42 4.77 1.44 2.74 3.81
67 15386 29319 40853 2.08 3.96 5.52 1.66 3.17 4.41
68 12952 24680 34389 1.75 3.33 4.64 1.40 2.67 3.71
69 13918 26521 36955 1.88 3.58 4.99 1.50 2.86 3.99
70 16545 31527 43930 2.23 4.26 5.93 1.79 3.40 4.74
TOTAL 1014676 1933452 2694086 136.98 261.02 363.70 109.59 208.81 290.96
4.3.1 Infiltration
Infiltration is basically the ingress of ground water in to sewer lines through joints. This
phenomenon occurs where the water table is high. CPHEEO has suggested (refer Table 4.3)
estimates for ground water infiltration for sewer laid below water table.
Table-4.3: Estimated Infiltration Flows As Per CPHEEO
Value Sr. No. Basis of Computation
Minimum Maximum
1 Area Basis, lit/ha/day 5000 50000
2 Sewer Length Basis, lit/km-day 500 5000
3 Manhole Basis, lit/day/ manhole 250 500
With good workmanship and improved quality control, the infiltration values tend to be on
lower side. Normally, infiltration value on minimum side is adopted in Indian conditions. Unless
established by field experiments, use of higher values would oversize the sewer pipes and may
lead to over sizing of treatment units. The comparison of infiltration values for this project is
presented in Table 4.4.
Table-4.4: Estimated Infiltration Flows (MLD) For The Project
Sr.
No.
Basis Of
Computation
Unit Project
Values
Value
Min. Flow Max. Flow
1 Area Basis Ha 14032 5000 70.16 50000 701.60
2 Sewer
Length Basis
Km 1032 500 0.51 5000 5.16
3 Manhole
Basis
Nos. 34500 250 8.62 500 17.25
Note: Number of manholes at 30 m spacing interval.
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As seen from computations, the infiltration considered on sewer length basis gives a minimum
values as compared to area and manhole basis computations. Hence in design of sewer system
for Raipur, it is appropriate to consider infiltration contribution using the sewer length basis.
4.4 Total Sewage Generation
The projected sewage quantity for the base year (2012), intermediate (2027) and ultimate
design year (2042) are presented in Table 4.5. The proposal of flow splitting is discussed in
Chapter- 7.
Table – 4.5: Minimum, Average and Peak Sewage Flow Projections for Different
Stages
Sr. No. Year Projected Flows* (MLD)
Minimum Average Peak
1 2012 57.38 114.77 229.53
2 2027 107 213.99 427.99
3 2042 148.07 296.14 592.28
*Flows including infiltration value
***
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Design Considerations 5555
5 Design Considerations
5.1 Introduction
RMC is divided in to 70 wards with total area of about 142 sq. km (refer Annexure-1). As
described in the Inception Report (section 3.3), there is negligible municipal (or central)
sewerage system. The residential and commercial buildings and educational institutions have
on-site septic tanks and soak pits to dispose the sewage. However it is also noted that probably
due to poor maintenance, overflows from these septic tanks and soak pits are common and find
its way to the nearby drain. Also, the existing oxidation ponds are defunct and the sewage
reaching them is bypassed into nearby drains. In this chapter, the subsequent sections present
considerations for design of sewage collection / sewage treatment system in RMC area.
5.2 Planning Considerations
The municipal sewerage system consist of a combination of building sewers (house connections),
lateral or branch sewers, collector sewers, sub-trunk sewers and trunk sewers. Sewerage
infrastructure is normally planned in such a way as to make best use of available funds while at
the same time meeting the needs of the community served. The design of cost-effective and
efficient sewage collection system is accomplished by proper layout and sizing of sewers. The
criteria normally adopted for design of sewerage system and sewage treatment are discussed in
brief as under.
5.2.1 Planning Horizon
Design period normally refers to the ultimate year of system design. As mentioned in section
4.3.5, Table 4.2 of the Inception Report, and also as per the recommendation in CPHEEO Manual
on Sewerage & Sewage Treatment (second edition), the design period for all sewers in the
system shall be 30 years, while pumping machinery shall be designed for 15 years. Hence the
design period is reckoned up to year 2042 (considering base year as 2012). The key input for
projections is statistical data, which in case of this project is the census 2001 data (refer the
Annexure-2).
5.2.2 Present and Future Land Use
The Comprehensive Development Plan of Raipur city was got prepared under JNNURM
(Jawaharlal Nehru National Urban Renewal Mission) in year 2006. According to this development
plan, percentage land use is depicted in Table 5.1. The development plan (Drawing No. STD-01)
has been studied with respect to land use pattern of Raipur municipal area for year 2011.
The area of the Raipur Municipal Corporation is about 142 sq.km and is spread over 70 wards.
With regards the existing land use (excluding the extension areas of the city) about 55.3% of
area is categorized as residential and 13.5% is assigned towards transport. The commercial and
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public use land constitutes 4.8% and 12.1% respectively. The land use details of the added areas
are unavailable.
Table-5.1: Land Use Classification
LUP-1998 Land Use Category
Area (hac) %
LUP-1991 Developed
Area-1998
Modified
LUP-2011
Residential 2050 55.30 2300 2050 3926
Commercial 180 4.80 280 180 467
Industrial 430 11.60 280 180 1237
PSP&PUF 450 12.10 950 450 1008
Recreational 100 2.70 550 100 2168
Transportation 500 13.50 820 500 1476
Total 3710 100 5180 3460 10282
Source: CDP for Raipur City
5.3 Sewer Design Considerations
The proposed sewerage system for Raipur will have four categories of sewers, namely, (i) Lateral
sewers, (ii) Collector sewers, (iii) Sub-trunk sewers and (iv) Trunk sewers.
Lateral sewers: these sewers form the basic network of sewers designated to convey the sewage
collected from households. Laterals will be laid along streets in residential areas.
Collector sewer: these shall form the secondary network of sewers where number of laterals
shall end into collector sewers. The sewers will be laid along major residential area roads.
Sub-Trunk sewers: these shall be the penultimate sewers to which collector sewers are tributary.
These sewers will transport sewage to the Trunk sewers.
Trunk sewers: these shall be the main sewers laid along the major roads of the city. They will
convey the sewage to the sewage treatment plant locations.
The classification that has been followed during design shall be as under;
Sewer Diameter range
Lateral 150 to 300 mm
Collector > 300 mm up to 500 mm
Sub-Trunk > 500 mm up to 1000 mm
Trunk > 1000 mm up to 2000 mm
The following basic elements are considered in the design;
� Location of horizontal alignment, which can most efficiently provide service to potential
users.
� The vertical restrictions on establishing the sewer alignment including: minimum cover,
conflicts with other underground facilities, hard strata and maintaining of the required slopes.
� Design flow generated in the service area.
� Pipes - size, material, bedding and method of construction required.
� The necessary appurtenances and special structures required.
5.3.1 General Location Criteria
The proposed sewer lines in RMC area are located using sound engineering judgment to
determine the most cost-effective and environmentally sensitive alignment that best serves the
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needs of entire project area. Though it is understood that the costs and acquisition time for
easements can be significant; therefore, sewers are proposed to be located within existing
easements and right-of-way whenever feasible and practical. While selecting the sewer
alignments, following general location criteria are being considered:
� Elevation requirements necessary to provide appropriate service with due consideration of
sanitary facilities in building.
� Existing utilities, railways, highways and other facilities.
� Location of proposed water lines and storm water drainage facilities.
� Potential damages to the affected properties.
� High flood levels.
� Anticipated extension of existing streets and the potential for the development of
contiguous areas.
� Continuity with adjacent design segments.
� Maintenance of traffic.
� Availability of materials.
� Foundation conditions.
� Construction cost.
5.3.2 Horizontal Alignment Criteria
As reasonably possible, the proposed sewers will be constructed with a straight alignment
between manholes.
5.3.2.1 Straight Streets
Sewers will be located on road / streets on the opposite side of the water main (where
identified) and at least 3 m away from the water main. Circumstances (narrow streets) may
require placing the sewer closer to the edge of pavement, but every effort will be made to place
the entire manhole frame and cover entirely within the pavement. In areas where location
conflict with other utilities is encountered, the sewer location will be adjusted to avoid these
conflicts. Consideration of other factors, such as the width of the pavement, depth of rock, and
possible conflict with other utilities shall be revisited as required so the sewer can be built with
least modifications during construction.
In areas where concrete pavement is encountered, consideration shall be given to placing the
sewer in a location whereby one edge of the pavement to be removed would coincide with
existing construction joints, which are generally in the centerline of the streets. This procedure
would require that only one side of the pavement would have to be sawed for removal. In areas
where lots slope abruptly away from the street, consideration shall be given to locating the
sewer near the property line on the low side.
5.3.2.2 Curved Streets
The sewer line shall be located outside the pavement if such an alignment proves to be cost-
effective. In such cases, the centerline of the manhole shall be at minimum distance of 1m from
the edge of pavement.
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5.3.2.3 Manhole / Sewer Designations
For easy identification, the proposed sewer segments are designated as under:
Manhole Numbering System: The following method is adopted for the designation of sewers in
the system.
Zone Trunk Sub-Trunk Collector Lateral Manhole ID
Range
Zone (Z) 01 to 03
Trunk Section (T) 01 to 99
Sub-Trunk Number (S) 01 to 99
Collector Number (C) 01 to 99
Lateral Number (L) 01 to 99
Manhole Number (M) 01 to 99
EG: First manhole on the first lateral connected to the collector 01 of subtrunk 01 and trunk
section 01 in zone 01 will be assigned a Manhole ID as Z01T01S01C01L01M01. This is the most
efficient way of addressing the manhole number and location in the sewerage system and would
be easy while working on GIS platform.
Pipe Numbering System: The sewer pipe between two manholes is numbered with reference to
the manhole present at its preceding and succeeding nodes.
EG: Z01T01S01M20-21 for a conduit formed by manhole 20 and 21 on subtrunk no. 01 of trunk
section 01 in zone 01.
5.3.3 Vertical Alignment Criteria
5.3.3.1 Sewer Depths
All the starting sewers, i.e. laterals (minimum 150 mm φ) shall have a minimum cover of 750 mm
in initial reaches. A minimum cover of 600 mm shall generally be maintained when crossing
under existing nallahs / streams, and the sewer line is encased in concrete. A separate parallel
collector sewer shall be considered in lieu of individual property service connection into the
main sewer in areas where the main sewer reaches depth beyond 3 m. The collector sewer, at a
higher elevation, shall end in a drop manhole or vertical stacks into the main sewer. However,
the depth of burial for sewers shall be as per the computations obtained from structural design of
buried sewers as per CPHEEO Manual (Refer Volume - VIII).
5.3.3.2 Sewer Gradient
All the gradients shall be referred to permanent bench mark levels in the project area. All
elevation levels shall be shown on plans. The hydraulic criteria represented in the design shall be
followed to determine the gradient of sewers.
5.3.3.3 Flooding and Ponding Areas
The top of manhole elevations shall be a minimum of 300 mm above existing high flood level.
However, when this minimum elevation causes the manhole to be above the natural ground
creating obstructive mound(s), the top of the manhole elevation shall be lowered to the natural
ground elevation and a watertight manhole lid and frame shall be specified. In general, the top
of manhole is flushing with road surface.
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5.3.3.4 Minimum Water Main Clearances
The following minimum clearance between the sewer and existing or proposed water mains
shall be used in establishing the sewer alignment:
Horizontal Clearance: The horizontal clearance shall be 3 m minimum. Where this is not possible,
proper encasing of sewer shall be proposed.
Vertical Clearance: The vertical clearance shall be at least 500 mm. The sewer shall be located
below the water main. Should it become necessary for the sewer to cross over the water main,
special precautions such as encasing and separation shall be proposed.
5.4 Appurtenances
Sewer appurtenances include manholes, building connections, junction chambers, etc. The
extract on spacing of manholes and construction material, as presented in CPHEEO is
reproduced below for reference and the same shall be followed in design.
5.4.1 Manholes
Manholes are proposed at every change of alignment, gradient or diameter, at the head of all
sewers and branches and at every junction of two or more sewers. Drop manholes is provided
where difference in two connecting sewer lines is more than 600 mm. Upto 900 mm diameter
sewers, the spacing of manholes shall be 30 m. For 900 to 1500 mm diameter sewers, the
spacing of manholes shall be 100 to 150 m. For 1500 to 2000 mm diameter sewers, the spacing
of manholes shall be 150 to 200 m. All sewers above 450 mm diameter shall be provided with
service manhole at intervals of 110 m to 120 m, with clear opening of 1200x900mm at top to
facilitate lowering of bucket.
All manholes shall be circular type of manholes with internal diameter varying from 0.90 m to
2.50 m. A minimum clear opening of 0.56 m shall be provided on all manholes to facilitate entry
for cleaning. For entry, all manholes shall be provided with suitable number of MS steps
encapsulated with PVC material.
All newly constructed manholes shall be provided with numbers. The assigned number for the
respective manhole shall be shown both on plan drawing and structure of manhole (preferably
cover).
5.4.2 Bedding for Pipes
The beddings which are generally adopted for laying sewers in trenches are of following type:
Class-A: Bedding may be concrete cradle or concrete arch
Class-B: Bedding having shaped bottom or compacted granular with a carefully compacted
backfill
Class-C: Ordinary bedding having a shaped bottom with lightly compacted backfill
Class-D: It is with flat bottom trench with no care being taken to secure compaction of backfill
The types of bedding details, as described above are presented in Drawing No. STD-15. The load
factors for different classes of bedding are given in Table 5.2.
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Table-5.2: Different Beddings for Pipes in Trenches
Class Condition Load factor
A a Concrete cradle-plain concrete and lightly tamped backfill 2.2
A b Concrete cradle-plain concrete with carefully tamped
backfill
2.8
A c Concrete cradle-RCC with P-0.4% Up to 3.4
A d Arch type concrete
RCC with P-0.4%
RCC with P-1.0%
(P is the ratio of the area of steel to the area of concrete
at the crown)
Up to 3.4
Up to 4.8
B Shaped bottom or compacted granular bedding with
carefully compacted backfill
1.9
C Shaped bottom or compacted granular bedding with
lightly compacted backfill
1.5
D Flat bottom trench 1.1
The CPHEEO manual recommends B or C type of bedding with granular compacted bedding. All
the gravity sewers are designed as per CPHEEO requirement of structural design of buried pipes.
The detailed design sheets are placed in Volume-VIII.
5.5 Concrete Encasement
Concrete encasements will be used when it is necessary to prevent floatation, when crossing
streams, nalla or rivers and where crossing over utilities with less than 500 mm of clearance, or
in areas where the sewer has less than the required cover. The typical details of sewer encasing
are provided in Drawing No. STD-12.
5.6 Railway Crossings
The following criteria shall be followed when the sewers are required to cross rail tracks. The
schematic details of rail track crossing of sewers are presented in Drawing No. STD-18.
• Sewers shall cross tracks at an angle as close to 90o as practical, but preferably never less
than 45o.
• Sewer lines crossing under rail tracks shall be constructed adopting technology permitted by
the railway authorities.
• Sewer lines laid longitudinally along rail right-of-way shall be located away from tracks or
other important structures. The distance shall be minimum 5 m away from the edge of last
track. If not possible, the sewer shall be encased.
• When placed along rail track right-of-way, the top of the pipe shall have a minimum cover of
2 m.
5.7 Highway Crossing
The sewer pipe alignments under City maintained roads, which are designated by their
governing agencies, are to be crossed, shall meet the following requirements (more stringent
criteria may be required on a case specific basis):
Sewers shall cross the roads at an angle as close to 90o as practical, but preferably never less
than 45o. Sewers shall not be placed under roadway bridges where there is a likelihood of
restricting the required area of the bridge or where there is a possibility of endangering the
foundations. Sewer lines laid in a longitudinal direction on highway right-of-way shall be located
at sufficient distance from the edge of pavement to allow adequate working room and to
provide maximum safety to the motorist when the roadway is to remain open to traffic. The
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sewer lines within the road right-of-way, but not located under paved areas, shall have minimum
1.5 m of cover.
5.8 Pipe Material
Sewer pipes are made from concrete, reinforced concrete, vitrified clay, asbestos cement, brick
masonry, cast iron, ductile iron, steel and plastic. Some of the important factors in selection of
sewer material include the following;
� Resistance to corrosion, scour and flow,
� Resistance to external forces and internal pressure,
� Soil conditions,
� Type of backfill and bedding material to be used,
� Useful life,
� Strength and water tightness of joints,
� Availability of diameter and length,
� Ease of installation, and
� Cost of construction and maintenance.
5.8.1 Technical evaluation of pipe material
Mostly the sewer network is planned as a gravity conveyance system to economize on cost. The
design depth for laying gravity sewers is normally restricted up to 6 m for large networks.
However, sometimes deep sewers (depth > 6 m) are required to be designed due to topographic
considerations (flat ground slope and large area to be served). The literature review reveals that,
all pipes can be laid up a depth of 7 to 10 m. Steel. Comparison between various pipes have been
done and presented in Table 5.3.
Table 5.3 : Characteristics of Sewer Pipes
Material Sizes
(mm)
Length
(metre)
Reference
Standard
Corrosion Strength Type of Joint Application
Concrete
(RCC)
80 - 2600 2 - 4 IS 458 Yes Good Collar, S&S Used for sewers,
force mains, siphons.
Low cost,
Vitrified
Clay
(Stone
ware)
100 - 600 0.60 –
0.90
IS 3006 No Brittle Mortar,
rubber gasket
Used for sewers,
short lengths, many
joints, more
infiltration
Ductile
Iron (DI)
80 - 2000 4 - 6 IS 8329 Yes Excellent Flanged,
coupled,
rubber ring
type push on
(S&S)
Used for force mains,
siphons, long lengths,
tight joints, high
pressure applications,
high cost
Cast Iron
(CI)
80 - 1050 3 - 6 IS 1536 Yes Excellent Flanged,
coupled,
rubber ring
type push on
Used for force mains,
Siphons, long lengths,
tight joints, high
pressure applications
Asbestos
Cement
IS 6908
IS 1592
Yes Good Collar with
rubber ring
Used for gravity, light
weight, easy handling
Plastic
(uPVC)
16 - 315 12 m IS 15328 No Fair Rubber
cement,
compression
gasket
Light weight, tight
joints, long length,
susceptible to
deflection, loss of
shape and strength
Steel (MS) 168 - 2540 4 - 7 IS 3589 Yes Good Coupling, bolt Used for sewers,
force main, siphons
and culverts
Size: In municipal gravity sewerage systems, size of sewers varies from 150 mm to 900 mm. At
times, for large networks, interceptor sewer leading to treatment plant may be of 1200 to 1600
mm diameter or even more. As seen from above table CI and DI pipes are available up to 1000
mm and 2000 mm diameter respectively. RCC pipes are available up to 2600 mm diameter. CI
and DI pipes are available in 100 mm increments of size. However RCC pipes are available in 50
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mm increment, which helps designer in accurate selection as compared to theoretical diameter
requirement.
Length: The pipe manufacturer’s specification (and also the IS codes) reveal that RCC, CI and DI
pipes are available from 2 m to 6 m working length, with an increment of 0.5 m. Smaller lengths
lead to large number of joints in the system. Where 150 to 700 mm pipes are used, long lengths
are adopted. While in case of pipes beyond 800 mm, short lengths are used. Normally 3 m, 3.5 m
and 4 m working lengths are preferred due to ease in handling while laying.
Corrosion: Pipes carrying sewage are prone to corrosion due to formation of gases like hydrogen
sulphide and methane. Except stoneware and PVC pipes, all other pipe materials are subjected
to varied degree of corrosion in their useful life. However, internal lining (in CI/DI) and corrosion
resistant cement use in RCC pipe may reduce or prolong the onset of corrosion process.
Strength: This is one of the important selection criteria for pipe material as the pipes are
required to be buried deep under ground and are subjected to various lateral and vertical forces.
RCC pipes are having “good” strength. DI and CI due their metallic properties are rated
“excellent” in case of strength.
5.8.2 Economic evaluation of pipes
While conducting economic analysis for selection of most economical material along with the
physical properties, cost of pipe also plays a crucial role. Selection of pipe material is often
derived by the initial cost of pipe. However, worldwide practice is to conduct lifecycle analysis of
pipe material to arrive at the most economical selection, which includes the project life, material
life, annual O&M requirements. In this case the project life is 30 years (starting from year 2012)
and the material life of pipes under consideration (i.e. RCC, CI and DI) is more than 50 years,
which effectively means
pipes will last for more
than the project life.
Thus the initial cost of
pipes is the major criteria
for selection of material.
Based on the Madhya
Pradesh State, PHED -
Unified Schedule of
Rates (September 2002),
for above pipes, the
comparison on initial
cost for per meter length
is presented in Chart
(side).
As seen from the above chart, RCC pipes (NP2 and NP3) are cost wise most economical for all
manufactured diameter ranges. Hence for gravity sewers, it is prudent to adopt RCC pipes
because of their low cost and wide availability. For rising mains from pumping station, the
economics of selection is mainly driven by strength of material and tightness of joints.
5.8.3 Recommendations on pipe material
Considering the various properties as described in section 5.9.1 above, it is recommended to use
RCC pipes of various grade (like NP2 and NP3) in design of sewerage network. Economically, RCC
pipes are cheaper as compared to DI/CI pipes for any considered diameter and are also readily
available in the market. For pumping mains, it is recommended to use DI (K7) pipes for their
excellent strength and long useful life, cost wise DI is marginally (about 2 to 4%) costlier over CI.
***
COST COMPARISON OF VARIOUS PIPE MATERIALS
075015002250300037504500525060006750750082509000975010500112501200012750135001425015000
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
DIAMETER (mm)
COST (Rs/m)
RCC NP2 RCC NP3 CI-(LA class) DI-K9 HDPE-P4
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Design Criteria 6666
6.0 Design Criteria
Many design and construction factors are required to be investigated before sewer design is
contemplated. Factors such as design period, peak, average and minimum flows, sewer size,
sewer slopes and velocity, design equation, sewer material, joints and connections,
appurtenances and sewer installations are all important in developing sewer design. The key
factors are discussed below.
6.1 Design Period
The design period for the project is reckoned up to year 2042.
6.2 Peak, Average and Minimum Flows
Sewers are designed to carry peak residential, commercial and industrial flows and normal
infiltration where unfavourable condition exists. The average flow projections are presented in
Chapter-4 above. As per the recommendations given in CPHEEO, peak factor for contributory
population is used in design of sewers. The minimum flow is taken as ½ of average flow, as per
CPHEEO.
6.3 Sewer Size
Minimum sewer size recommended in CPHEEO manual is 150 mm. The criterion governing the
minimum size of gravity sewer is to reduce the possibility of clogging. For this project, the
minimum sewer pipe size is 150mm, which is inline with recommendation by CPHEEO. While it is
acknowledged that 100mm diameter sewer for small bore sewer system has been successfully
used in some parts of India, this is deemed not very appropriate for Raipur city.
6.4 Slope
Inadequate sewer slopes encourage solids deposition and production of noxious gases (H2S, CH4,
etc.), causing corrosion and early decay of pipe. CPHEEO manual has recommended slopes for
attaining minimum velocity of 0.6 m/s in sewers. These slope values are computed for different
peak flows and correspond to sewer flowing partially full (i.e. d/D=0.8). Literature also
recommends approximately same slopes for design of sewers at peak flow. The basis of
calculations is described below and the recommended slopes (to be referred in design) for
various diameters of pipes are given in Table 6.1.
Table – 6.1: Slopes at Peak Flow for Different Sizes
Slope
Sr. No. Diameter, mm m/m 1 in
Slope, m per
1000m
1 150 0.006 167 6.00
2 200 0.004 250 4.00
3 250 0.0028 357 2.80
4 300 0.0022 455 2.20
5 350 0.0017 588 1.70
6 400 0.0014 714 1.40
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Table – 6.1: Slopes at Peak Flow for Different Sizes
Slope
Sr. No. Diameter, mm m/m 1 in
Slope, m per
1000m
7 450 0.0012 833 1.20
8 500 0.001 1000 1.00
9 600 0.0008 1250 0.80
10 700 0.00067 1493 0.67
11 800 0.00058 1724 0.58
12 900 0.00046 2174 0.46
13 1000 0.00038 2632 0.38
14 1200 0.00032 3125 0.32
15 1400 0.00026 3846 0.26
6.5 Velocity
In municipal sewers, solids tend to settle under low velocity conditions. It is recognized that self-
cleansing velocities must be developed atleast once in a day to flush out the solids. A good
design is one which allows for generation of minimum velocity of above 0.45 m/s under low flow
conditions. Under peak dry weather flow condition, the sewers are designed to attain a velocity
greater than 0.6 m/s. However, the maximum velocity shall be kept less than 3.0 m/s so as to
avoid erosion of pipes and damage to manholes in long term.
6.6 Depth
Depth of bury affects many aspects of sewer design. Slope requirements may drive the pipe
deep into the ground, increasing the amount of excavation required to install the pipe. The
proper depth of bury also depends on water table, the lowest point to be served (such as ground
floor or basement), topography of the ground, etc. As far as possible, the depth of the sewer is
kept to a minimum. Checks are presented for adequacy of soil cover at important locations like
crossings (road, water course, etc), as per the provisions in CPHEEO manual.
6.7 Design Equation
The sewer system is designed to carry ultimate stage design peak flow. The available head in
wastewater is utilized in overcoming surface resistance and attaining kinetic energy for flow.
Literature reports extensive use of Manning’s formula as design equation for circular gravity
sewers. The concept of design is presented as under.
Flowing full: The average and peak flows (including infiltration) are established for various design
periods (immediate, intermediate and ultimate) and the layout and topographic features for
each sewer line are established, then the sizing of sewers is done. Design equation proposed by
Manning is used for designing sewers. The equation is presented as under;
V = 1/ηηηη x R2/3
x S1/2
Where,
V : velocity of sewer flowing full, m/s
R : Hydraulic mean radius = A/P (pipe flowing full R=D/4), m
D : Diameter of pipe, m
S : Invert slope or slope of energy grade line, m/m
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η : Coefficient of roughness
The coefficient of roughness depends on the material and age of pipe used, commonly used
values of ‘η’ are mentioned in Table 6.2.
Table – 6.2: Value Of ηηηη For Different Pipe Material
Sr. No. Pipe Material Condition ηηηη
Good 0.012 1 Salt Glazed Stone ware pipe
Fair 0.015
Good 0.013 2 RCC pipes (collar joint)
Fair 0.015
3 RCC pipes (S&S joints) - 0.011
welded 0.013 4 Steel
riveted 0.017
5 Steel with spun cement lining - 0.011
Unlined 0.013 6 Cast Iron (CI)
Lined 0.011
7 AC pipes 0.011
8 Plastic smooth 0.011
Partially flowing full: Municipal sewers are normally designed as partially flowing full. This is
because of the consideration of ventilation in sewer. CPHEEO recommends design of sewer to
flow 0.8 full at ultimate peak flow. Literature and the manual reports the hydraulic elements of
circular sewer under different depth conditions. The elements are reproduced in Table 6.3 and
chart is placed below.
Table – 6.3: Hydraulic Properties of Circular Section
constant ηηηη
d/D v/V q/Q
1.0 1.000 1.000
0.9 1.124 1.066
0.8 1.140 0.968
0.7 1.120 0.838
0.6 1.072 0.671
0.5 1.000 0.500
0.4 0.902 0.337
0.3 0.776 0.196
0.2 0.615 0.088
0.1 0.401 0.021
The hydraulic elements at d/D=0.8, shall be used in design of all the sewers flowing under gravity
influence.
Increasing size: When a certain size sewer is connected to a larger one at a manhole, the
connection shall be matching the 0.8 depth point of both sewers to the same elevation.
Wherever, possible crowns of the two pipes are matched.
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HYDRAULIC ELEMENTS OF CIRCULAR SEWER AT CONSTANT n
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3
Hydraulic Elements q/Q, v/V
Ra
tio
of
de
pth
to
dia
me
ter
d/D
q/Q
v/V
6.8 Manholes (Regular and Drop)
The distance between manholes for various diameters shall be as per CPHEEO manual. It is
proposed to adopt prefab RCC manholes. This would aid in fast construction providing better
strength and long useful life while serving its purpose. The proposal on manholes is already
presented in section 5.4.1. A typical manhole and drop manhole with details are presented in
Drawing No. STD – 09, STD – 10, STD - 13 and STD - 14, respectively.
6.9 Property Connection
Table 6.13 of CDP for Raipur, explains that during year 2012-2013, about 75,000 domestic sewer
connections, 5000 commercial connections and 2200 industrial connections would be achieved.
The property connections could be made through 150 mm diameter PVC pipe (4 kg/sqcm)
connected from house/property chamber to sewer manhole. The cost for same is considered in
the detailed project estimates. The typical details of connecting the proposed sewer system to
individual properties are provided in Drawing No. STD – 11.
***
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Design of Sewers 7777
7.0 Design of Sewers
In this project, the design of sewerage system and proposals of STP are required to be planned
for 30 years. Considering the construction period of 28 months, the base year for commissioning
of sewerage system / STP is therefore taken as year 2012-13. Correspondingly the intermediate
phase of year 2027 and ultimate phase of year 2042 have been arrived with interval of 15 years.
The sewerage system is planned and designed for flows generated up to year 2042 (ultimate
phase) and STPs are designed in two phases.
� Intermediate phase: Design of STPs for flows up to year 2027.
� Ultimate phase: Module design for flows beyond year 2027 and up to year 2042.
7.1 Salient Design Considerations – Gravity Sewers
Dry Weather Flow : 80% of water supply (i.e. 135 lpcd water supply)
Peak Factor : As per CPHEEO depending on the contributory population
Design Equation : Manning Formula , with n=0.011
Sewer Material : RCC NP2 / NP3 pipe for laterals, collector, sub-trunk and trunk sewers.
NP4 pipe where NP3 fails in deep trenches
Velocity : Min. Velocity ≥ 0.6m/s (0.45 m/s in initial reaches to minimize depth)
Max. Velocity ≤ 3m/s
Depth of Flow : All sewers flowing ≤ 0.8 full (CPHEEO)
Infiltration : Average of 5000 lit/Km/day
Minimum
Diameter
: 150 mm
Maximum Depth
of Invert
: The maximum depth of invert shall be 6 - 7 m. In exceptional cases,
like crossings, drop manholes and at pumping station locations larger
depths up to 8m shall be considered (Case specific basis).
Minimum Cover : Without protection 0.75m (up to top of pipe)
With protection (encasing) 0.5m (up to top of encasement).
Bedding : Granular compact bedding 150 mm (minimum) or as per design (refer
Volume –VIII).
Backfill : Mechanically compacted and compaction density measured up to
acceptable levels or as specified based on soil analysis
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Joints : Flexible with adequate water tightness measures like rubber ring for
RCC pipes. For large pipes (dia>900mm) pipe joints shall be wrapped
with geo-textiles with 300mm overlap on either side of joint (typically
S&S Joint)
Testing of Sewer : As per recommendations of CPHEEO manual
Cement : Sulphate resistant cement shall be used for pipes and manholes
Design Loading : Structural design of buried pipes (As per CPHEEO – refer volume VIII)
Pipe Strength : As per relevant BIS Code
Manholes : Location
(a) At change of slopes in Pipeline
(b) At change of direction
(c) At junctions
(d) At change of pipe diameter
(e) At termination sewer
(f) At any designed special location
Spacing
(c) Up to 900 mm dia . - 30m c/c
(d) 900 to 1500 mm dia-100m c/c
Manhole Cover
Levels
: Paved Areas: Cover level = Final paved level
Unpaved Areas: Cover level=Final G.L.+0.10m
Open Spaces: Cover Level=Final G.L.+0.20m
Flood Areas: Cover level= Final G.L.+0.30m
Manhole Cover : Steel Fibre Reinforced Concrete (SFRC)
Manhole Material
and Shape
: Prefabricated RCC Circular Manholes with rubber rings for proper
joints.
Use of sulphate resistant cement is recommended
Vent Shafts : Not Recommended
Silt Chambers : Not Recommended
Type of
Excavation
: Open excavation in all areas. For deep sewers shoring / sheet piling
shall be adopted, as required
Soil Tests : GT investigations to be carried out for determining bearing capacity of
soil at STP and SPS locations
7.2 Population Density
As per the population projections in Chapter-3, by year 2042, the population would be about
26.94 lakhs.
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As brought out earlier in the inception report, there is no centralized sewerage system in the
RMC area. The details of the same are already discussed in Chapter 1. To design sewers for the
ultimate year 2042, following is presented.
� The Raipur city has a geographic area of 14032 hac. This city development plan is divided in
to eight administrative zones as per the City Development Plan, 2005-2030.
� For growing cities, planners recommend a population density between 60 -1 00 persons/hac
(6000 to 10000 persons / sq. km.) as design basis for planning/designing city infrastructure.
Raipur, growing in trade and commerce activities need future and concurrent infrastructure
to cater for atleast 3 decades. Considering this aspect, and with no existing sewerage
infrastructure, it is prudent to design a system to cater for population density of 125
persons/hac.
� To cater for about 26.94 lakhs population of year 2042, it is expected that the RMC
administrative area would increase, thus de-centralizing the congested existing city areas.
This would allow for reduction in population density.
� The RMC population profile reveals that, the central core area is most populous, with
density of population above 125 persons/hac. There are 25 wards (1 to 6, 12 to 15, 26 to 28,
45, 46, 51, 52, 54, 60, 62, 63, 67 to 70) having population density less than 100 persons/hac.
� These wards constitute 81.67% (115.46 sq. km.) of current RMC area. 11 wards (7, 9, 23, 29,
32, 35, 40, 42, 49, 50, 66) are having population density between 100 to 150 persons/hac
and constitute 6.98% (9.8 sq. km.) of current RMC area. Remaining 34 wards are having
density beyond 150 persons/hac. This trend is observed because wards areas are varying in
size.
POPULATION DENSITY
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69
WARD
DE
NSIT
Y, PE
RS
ON
S/H
AC
YEAR 2012 YEAR 2042
� Overall, considering the potential of Raipur city to assume growth, irrespective of expansion
in RMC area, the city level sewerage is expected to be always under stress. Hence the
sewerage system with capacity to serve up to year 2042 would be most beneficial. Also this
future foresight would help land use planners in their master plan proposals.
� The trunk sewers (major and deep sewer lines), sub-trunk, collector and lateral sewer lines
are designed for year 2042 flows.
7.3 Sewerage Zones
In most of the sewage conveyance systems, the network is sub-divided in to zones (or sewerage
districts) to sustain maximum gravity flows, reduce / eliminate intermediate pumping stations
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and have better O&M control after commissioning. The zoning is based on topographical
features (slope, water bodies, etc.) of the area and location of treatment / final disposal point.
Topographically, almost 56% of project area is having slope from south to north direction. The
relief ranges from 305 m in west – northwest to 270 m in east & north-east. The southern
boundary follows the Kharun river. This project area is characterized by presence of many
ponds/lakes and nallahs. There are three major relief lines in the project area which are
considered for zoning.
� The eastern part of city, starting from extreme south (ward no. 52) and extending up to
extreme north (ward no. 26).
� The western part of city consisting of northern parts of Hirapur/Jarvay, Sondongari, Gogaon
& Gudhiyari areas and sloping in north direction leading to northern city limits.
� The western part of city on southern side of Hirapur/Jarvay, Sondongari, Gogaon &
Gudhiyari areas and extending towards southern city limits.
On the basis of above distinction, the project area is sub-divided in to three sewerage zones (I, II
and III) and the design proposals are presented separately. The sewerage zoning map is
presented as Drawing No. STD-02.
7.3.1 Zone – I
This zone forms the eastern part of city. The west side of this zone is bound by Mathpurena,
Santoshi Nagar, Budha Talab, Ganjpara & the railway line to Hawrah. Area of zone-I is about
48.66 sq. km. (i.e. 34.26% of project area). Zone-I comprises ward number 5, 6, 22 to 35, 40, 42
to 51 and the base year population is 3,15,665 souls. The ultimate population for zone-I is
projected as 8,38,128 souls. On the basis of population projections the immediate (year 2012),
intermediate (year 2027) and ultimate (year 2042) sewage generation from this zone is
calculated at 34.09 Mld, 64.96 Mld and 90.52 Mld respectively (refer Table 7.1).
Table - 7.1: Area, Population and Sewage Generation on Zone - I
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
5 0.43 2383 4540 6327 0.26 0.49 0.68
6 1.85 5863 11172 15567 0.63 1.21 1.68
22 0.41 13229 25209 35126 1.43 2.72 3.79
23 0.87 13758 26215 36528 1.49 2.83 3.95
24 0.46 13451 25631 35715 1.45 2.77 3.86
25 0.59 13847 26386 36767 1.50 2.85 3.97
26 9.92 16017 30520 42527 1.73 3.30 4.59
27 10.68 14186 27031 37666 1.53 2.92 4.07
28 5.84 16635 31698 44168 1.80 3.42 4.77
29 0.95 13936 26554 37001 1.51 2.87 4.00
30 0.58 12402 23632 32929 1.34 2.55 3.56
31 0.39 13728 26159 36450 1.48 2.83 3.94
32 0.75 14361 27365 38131 1.55 2.96 4.12
33 0.45 13252 25251 35185 1.43 2.73 3.80
34 0.49 13870 26429 36827 1.50 2.85 3.98
35 0.87 12541 23896 33297 1.35 2.58 3.60
40 0.44 7942 15133 21086 0.86 1.63 2.28
42 0.89 16164 30800 42917 1.75 3.33 4.64
43 0.72 16390 31231 43518 1.77 3.37 4.70
44 0.61 16042 30568 42594 1.73 3.30 4.60
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Table - 7.1: Area, Population and Sewage Generation on Zone - I
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
45 2.01 13461 25649 35740 1.45 2.77 3.86
46 6.90 12517 23851 33233 1.35 2.58 3.59
47 0.46 11599 22103 30798 1.25 2.39 3.33
48 0.47 10480 19970 27827 1.13 2.16 3.01
49 0.09 1720 3277 4566 0.19 0.35 0.49
50 0.36 4885 9309 12971 0.53 1.01 1.40
51 0.19 1005 1915 2668 0.11 0.21 0.29
Total 48.66 315665 601495 838128 34.09 64.96 90.52
7.3.2 Zone – II
This zone forms the north-western part of the city and the right portion of this zone is bound by
Raiway line to Howrah and lower portion is marked northern half of Hirapur/Jarvay, Sondongari,
Gogaon and Godhiyari area. Area of zone-II is about 33.97 sq. km. (i.e. 23.92% of project area).
The base year population of this zone is 325,122 souls. On the basis of population projections
the immediate (year 2012), intermediate (year 2027) and ultimate (year 2042) sewage
generation from this zone is calculated at 35.11 Mld, 66.91 Mld and 93.23 Mld respectively
(refer Table 7.2).
Table - 7.2: Area, Population and Sewage Generation on Zone - II
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
1 7.20 8025 15292 21308 0.87 1.65 2.30
2 4.47 14297 27243 37961 1.54 2.94 4.10
3 1.32 16536 31509 43905 1.79 3.40 4.74
4 5.46 16441 31328 43653 1.78 3.38 4.71
5 2.30 12827 24442 34057 1.39 2.64 3.68
6 2.30 7318 13944 19430 0.79 1.51 2.10
7 1.09 15745 30002 41805 1.70 3.24 4.51
8 0.77 16266 30994 43187 1.76 3.35 4.66
9 1.07 15196 28957 40348 1.64 3.13 4.36
10 0.44 16230 30925 43092 1.75 3.34 4.65
11 0.64 13932 26547 36990 1.50 2.87 3.99
12 0.99 9555 18208 25371 1.03 1.97 2.74
15 0.72 8070 15378 21428 0.87 1.66 2.31
16 0.44 14070 26809 37356 1.52 2.90 4.03
17 0.63 12935 24647 34343 1.40 2.66 3.71
18 0.46 15939 30372 42320 1.72 3.28 4.57
19 0.20 15524 29581 41219 1.68 3.19 4.45
20 0.71 16199 30867 43010 1.75 3.33 4.65
21 0.55 12707 24213 33739 1.37 2.62 3.64
22 0.01 222 423 589 0.02 0.05 0.06
35 0.12 1754 3342 4657 0.19 0.36 0.50
36 0.56 14456 27546 38383 1.56 2.98 4.15
37 0.56 14648 27911 38891 1.58 3.01 4.20
38 0.30 16102 30683 42754 1.74 3.31 4.62
39 0.13 7529 14347 19992 0.81 1.55 2.16
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Table - 7.2: Area, Population and Sewage Generation on Zone - II
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
40 0.26 4727 9007 12550 0.51 0.97 1.36
41 0.20 6343 12086 16840 0.69 1.31 1.82
57 0.08 1528 2912 4058 0.17 0.31 0.44
Total 33.97 325122 619516 863238 35.11 66.91 93.23
7.3.3 Zone – III
This zone starts on southern half of Hirapur/Jarvay, Sondongari, Gogaon and Godhiyari area and
forms the south-central part of the city draining towards Kharun river. Zone-III covers about
57.71 sq. km. (i.e. 40.64% of project area). Zone-III comprises ward number 1, 2, 12 to 15, 39, 41,
46 to 70 and the base year population is 3,73,889 souls. On the basis of population projections
the immediate (year 2012), intermediate (year 2027) and ultimate (year 2042) sewage
generation from this zone is calculated at 40.38 Mld, 76.94 Mld and 107.21 Mld respectively
(refer Table 7.3).
Table - 7.3: Area, Population and Sewage Generation on Zone - III
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
1 7.1845 8013 15269 21275 0.87 1.65 2.30
2 0.6985 2233 4256 5930 0.24 0.46 0.64
12 0.5889 5677 10818 15074 0.61 1.17 1.63
13 1.8900 15030 28640 39908 1.62 3.09 4.31
14 3.6500 13180 25114 34993 1.42 2.71 3.78
15 0.6325 7115 13558 18892 0.77 1.46 2.04
39 0.0824 4865 9269 12916 0.53 1.00 1.39
41 0.1940 6278 11962 16668 0.68 1.29 1.80
46 0.5705 1035 1972 2748 0.11 0.21 0.30
47 0.1018 2579 4913 6846 0.28 0.53 0.74
48 0.2501 5579 10631 14813 0.60 1.15 1.60
49 0.6730 13294 25331 35296 1.44 2.74 3.81
50 0.5776 7786 14836 20672 0.84 1.60 2.23
51 2.4306 12896 24573 34241 1.39 2.65 3.70
52 4.3700 14865 28324 39467 1.61 3.06 4.26
53 0.4700 16260 30984 43173 1.76 3.35 4.66
54 1.0400 12995 24762 34503 1.40 2.67 3.73
55 0.2000 15473 29484 41084 1.67 3.18 4.44
56 0.2500 13730 26162 36454 1.48 2.83 3.94
57 0.5449 11096 21143 29461 1.20 2.28 3.18
58 0.2100 12891 24563 34226 1.39 2.65 3.70
59 0.1000 12782 24356 33938 1.38 2.63 3.67
60 1.0300 13291 25325 35288 1.44 2.74 3.81
61 0.3900 13873 26435 36834 1.50 2.85 3.98
62 1.4600 14462 27557 38398 1.56 2.98 4.15
63 9.5200 16396 31242 43532 1.77 3.37 4.70
64 0.5300 15320 29191 40675 1.65 3.15 4.39
65 0.3100 12801 24392 33988 1.38 2.63 3.67
66 0.8000 13295 25333 35299 1.44 2.74 3.81
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Table - 7.3: Area, Population and Sewage Generation on Zone - III
Population Sewage Generation (MLD) Ward
No.
Area,
KM2
2012 2027 2042 2012 2027 2042
67 1.6400 15386 29319 40853 1.66 3.17 4.41
68 5.9200 12952 24680 34389 1.40 2.67 3.71
69 2.3200 13918 26521 36955 1.50 2.86 3.99
70 7.0800 16545 31527 43930 1.79 3.40 4.74
Total 57.71 373889 712440 992720 40.38 76.94 107.21
7.4 Trunk Sewers
The sewerage system for Raipur as described earlier is being designed for peak flows of year
2042. Since the city gets divided in to three parts as described in the preceding section, the
proposals for routing of main trunk sewers through the zones are presented henceforth.
7.4.1 Zone – I
Zone - I acquires eastern part of city. Major road running from south to north direction acts as
main line for routing of sewer. The topography of this zone slopes in south to north up to the
northern most city limits. The relief ranges from 304 m to 272 m at proposed STP area beyond
Daldal Seoni area. Part of zone-I is already provided with sewerage network (as discussed in
section 1.3.1). After detailed study of topographic profile of zone-I, the trunk sewer is proposed
as gravity sewer. However, it is observed that there are certain local depressions in this zone
which cannot be connected to the trunk line leading to the STP. Due to multi directional slopes
that too going away from main trunk sewer, there would be deep burial of sewers. To avoid this,
it is proposed to provide five sewage pumping stations (SPS). The proposal for providing trunk
sewers is described as under and the map of Zone-I showing sewer alignment and SPS locations
is placed as Drawing. No STD - 03.
• The Trunk-1 culminates at the STP which would be followed by Trunk-2, Trunk-3, Trunk-4,
Trunk-5 and Trunk-6. This means to say that Manhole no. Z01T06M49 will be the start point
of this trunk sewer and will end at manhole no. Z01T01M01 at the discharge point to the
STP beyond the existing oxidation ponds at Daldal Seoni. The length up to this point would
be 267895 m. This section would serve ward no. 5, 6, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33,
34, 35, 40, 42, 43, 44, 45, 46, 47, 48, 49 and 50.
• The Trunk-7 followed by Trunk-8 and Trunk-9 would discharge its sewage load at the SPS-C
of this Zone-I, with intermediate lifting stations, SPS-A and SPS-B. The length of sewer
feeding this sewage pumping station (SPS-C) would be 58107 m. The outflow from this
pumping station is achieved by a suitable size rising main into a subtrunk sewer leading upto
manhole no. Z01T03M31 on the main trunk line leading to the STP.
• Similarly, Trunk-10 and Trunk-11 will discharge its sewage load by gravity into SPS-D of this
zone. The length of the sewer upto this pumping station would be 45072 m. The outflow
from this pumping station is achieved by rising main of length 1260 m. This section would
serve ward no. 22, 23, 25 and 35.
• The 5th
sewage pumping station of this Zone, SPS-E is a lifting station located along Trunk-1.
• The total length of trunk sewers in this zone is 24207 m.
7.4.2 Zone – II
This zone is on the north-western side of Raipur city, covering 24% of project area. The southern
portion of this zone is characterized by a well drawn network of roads with elevation ranging
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between 295 m and 281 m. With respect to above features the proposal for trunk sewers is as
under and the map of zone-II showing sewer alignment and SPS locations is placed as Drawing.
No. STD - 04.
• The main trunk sewer is to start at manhole Z02T04M99. The trunk sewer would follow the
gravity profile up to the STP of this Zone-II at Rawabhata traversing a length of about 10360
m. This stretch has a fall from elevation 297m to 280m. This section would cover ward no. 3,
4, 7, 8, 9, 10, 11, 17, 20, 21, 22, 35, 36, 37, 38, 39, 40, 41 and 57.
• The Trunk-2 serves the SPS-A and SPS-B of this zone by gravity. It covers Ward nos. 3, 4 and
7.
• Similarly, SPS-C is fed by Trunk-5 of this zone. This involves a length of 11517m. The length
of pumping main would be 1205 m.
• The SPS-D will be covering Ward nos. 4, and 5. The length of this section is 23704 m. The
rising main from this SPS would have a length of about 1415 m.
• SPS-E of this zone is served by Trunk-7 involving a sewer length of 41242m.
• Similarly, SPS-F is served by Trunk 9 followed by Trunk-8. It covers a sewer length of about
70142m. The rising main from this SPS shall be 840m in length and discharge its flow into a
lateral of Trunk-3.
• The total length of trunk sewer in this zone would be 21993 m.
7.4.3 Zone – III
This zone is on the south-western side of Raipur city, covering 41.11% of project area. The
northern portion of this zone is characterized by a well drawn network of roads with elevation
ranging between 298 m and 277 m. With respect to above features the proposal for trunk
sewers is as under and the map of zone-III showing sewer alignment and SPS locations is placed
as Drawing. No. STD - 05.
• The main trunk sewer consists of two branches. The first branch is to start at manhole
Z03T04M71 and the second branch would start at manhole Z03T07M97. The trunk sewers
would follow the gravity profile up to the STP of this Zone-III near Kharun river traversing a
length of about 340070 m. This stretch has a fall from elevation 298m to 278m.
• The Trunk-8 serves the SPS-A of this zone by gravity. It covers Ward nos. 46, 51, 52 and 63.
The length of this section is about 14736 m.
• Similarly, SPS-B is fed by Trunk-9 of this zone. This involves a trunk sewer length of 2208 m.
The length of pumping main would be 1278 m.
• The total length of trunk sewer in this zone would be 19623 m.
7.5 Sewer Design
The sewage generating potential of the entire municipal area within which the development is
located, is addressed in the design of trunk sewers. The drainage basin as per topographic maps
of Survey of India and field survey for all areas with potential to be served, where no current
master sewerage plan exists has been considered marking the trunk sewer alignments. The trunk
sewers, sub-trunk, collector and lateral sewers are planned adjacent to the existing street / road
alignments and potential points of entry of sewage from surrounding properties has been
considered. Present and future anticipated land use, with equivalent projected population, is
being used to generate potential sewage flows. All calculations are tabulated for each trunk
sewer section.
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Equivalent Population: The equivalent population is considered as calculated in zoning
information (ref. section 7.3). The sewage generation rate is calculated at 80% of water supply
(using 135 lpcd water supply rate). The area-density method is being adopted to compute the
load of flow on each trunk. Area distribution on each trunk section is taken as the drainage
boundary falling at the end of particular section. The area obtained is multiplied by the density
of population to know the contributory population on that trunk section. Thereafter using 135
lpcd water supply and 80% of it a wastewater, the quantum of flow load on that trunk section is
fixed. Peak factor is considered on the basis of contributory population as per CPHEEO manual
guidelines. The ground elevation (spot level) is adopted from topographic survey of roads in the
city. The hydraulic design using customized MS-excel spreadsheets (Table 7.4) is submitted as
Volume – II.
The hydraulics of gravity sewer is modeled for uniform slope between two sections of the
manholes. The minimum velocity is kept as 0.45 m/s in the initial reaches of lateral sewers. This
is considered to reduce the depth of excavation for sewers. Theoretical flow is computed by
adding infiltration flow. On the basis of contributory population on the section, peak factor is
selected to arrive at peak flow. The computed peak flow, diameter of pipe is selected and depth
of flow in pipe is utilized in computing d/D ratio. Simultaneously the carrying capacity of pipe is
checked against the generated peak flow. There after invert level and crown level are computed
using slope and minimum depth of cover.
Where two or more sewers are joining, the crown of sewers is matched and the minimum of
invert level is carried forward for down stream sewer design.
Slope and diameter values are dynamic in the design and can be changed while checking for the
hydraulic properties of sewer, like, v/V, d/D, qf/Q.
Minimum diameter of sewer adopted in design is 150 mm. RCC NP2 and NP3 pipes are proposed
in design. The depth of sewer laying is limited at 7 to 8 m, and an intermediate sewage pumping
station is proposed at such location. The design of sewage pumping station is given in Chapter-8.
The cost estimate for trunk, sub-trunk, collector and lateral sewers is prepared separately on the
basis of Unified Schedule of Rates of PHED (effective since September 2002) and for items not
falling in this schedule of rates, the rates as given in CPWD, Delhi Schedule of Rates, year 2007
with a current cost index of 64% are adopted. The detailed cost estimate for all sewers is placed
in Volume - IV.
7.6 Summary of Sewer Design
The total gravity sewer length proposed under this DPR is 1032 km. The zone wise summary of
design is given below in Table 7.5.
Table 7.5: Summary of Design Length
LENGTH in m ZONE TRUNK NO.
TRUNK SUBTRUNK COLLECTOR LATERAL
TOTAL
LENGTH
(m)
1 2574.34 7187.33 12573.14 15956.56 38291.36
2 2209.95 9465.27 24952.18 59588.59 96215.99
3 2246.03 10496.60 15221.43 37174.58 65138.64
4 2163.69 8276.95 7494.72 1939.34 19874.71
I
5 2328.37 7714.08 8778.73 5920.23 24741.40
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Table 7.5: Summary of Design Length
LENGTH in m ZONE TRUNK NO.
TRUNK SUBTRUNK COLLECTOR LATERAL
TOTAL
LENGTH
(m)
6 1101.75 4753.91 8079.09 9612.74 23547.48
(7, 8 & 9) 7569.98 20638.01 19436.21 10462.37 58106.57
(10 & 11) 4012.31 12930.48 17173.21 10955.40 45071.40
TOTAL (I) 24206.43 81462.62 113708.71 151609.80 370987.56
1 2763.82 135581.83 7789.75 6502.18 152637.58
2 2912.32 3959.97 7999.31 11421.63 26293.23
3 2216.81 13691.84 32877.74 43118.21 91904.60
4 2467.20 6904.07 7789.75 6502.18 23663.19
(5) 2392.43 5664.76 3134.18 325.58 11516.95
(6) 2318.23 6161.37 9716.77 5507.84 23704.20
(7) 2175.58 11428.27 15377.13 12261.45 41242.42
(8 & 9) 4746.50 21348.62 25420.51 18626.61 70142.23
II
TOTAL (II) 21992.90 204740.72 110105.12 104265.67 441104.41
1 2622.04 6493.62 5928.07 3476.03 18519.76
2 0.00
3 2722.30 10149.74 18976.69 15171.26 47019.99
4 1886.68 3500.19 3043.30 4378.06 12808.24
5 2665.15 6604.35 11139.22 44802.33 65211.04
6 2882.96 4659.58 2856.05 579.51 10978.10
7 2708.67 5145.73 9118.62 11019.29 27992.31
(8) 1927.47 4497.17 4553.61 3757.92 14736.17
(9) 2208.04 8568.17 7701.85 3514.80 21992.86
III
TOTAL (III) 19623.31 49618.57 63317.41 86699.18 219258.48
TOTAL 65822.64 335821.92 287131.24 342574.65 1031350.45
***
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Design of Sewage Pumping Station 8888
8.0 Sewage Pumping Station
Sewage pumping stations are normally required to remove / lift wastes from areas which cannot
be served hydraulically by gravity sewers. In certain situations however, a gravity sewer system
can be utilized, but only at the expense of deep trench excavation, jacking, boring or tunneling.
In such cases, both sewage pumping and gravity flow sewers are technically feasible and capable
of meeting service requirements. However, they may not be equivalent in economic terms. The
design of a sewage pumping station typically include site selection, structures, screening and
flow monitoring devices, pumping units, pump accessories, system controls and
instrumentation, mechanical and electrical components, interior piping, underground rising
mains, valves and appurtenances.
8.1 Site Selection
The location of pumping station within a service area is based primarily on topographic
considerations and the need to provide for future development. The location of pumping
stations is being made considering the availability of land and required utilities such as electric
power, potable water, fire protection and telephone service.
8.2 Building and Structures
The invert elevation(s) of incoming sewer(s) determines the depth of underground portion
(substructure) of the pumping station. Subsurface and soil conditions at the site govern the
structural design, excavation depths, and foundation. Surface conditions such as adjacent
buildings and site grading are considered in the design of superstructure. The ground floor will
be set above the maximum expected flood level.
8.3 Access Road
Pump stations will be readily accessible by an all weather access road. Since submersible pump
stations are envisaged, provisions are included in the structure to facilitate access for repair and
to provide a means for removal and loading of equipment onto a truck.
8.4 Pumping Capacity
Proper selection of the number and capacity of pumping units is dependent upon the quantity
and variation of sewage flows to be handled. Pumps are selected to handle the normal daily
range of sewage flows generated in the service area. The number and capacity of pumps
provided is sufficient to discharge the minimum, average, peak daily flow rates as calculated.
Pumping capacity is adequate to discharge the peak flow rates with the largest pump out of
service.
8.5 Rising Main Hydraulics
The pipeline which carries sewage from the pumping station to the point of discharge is called a
rising main (or force main). Rising mains are designed as pressure pipe, and have adequate
strength to withstand an internal operating pressure equal to the pump discharge head, plus an
allowance for transient pressures caused by water hammer. The internal operating pressure is
maximum at the pumping station, and is reduced by friction to atmospheric, or near
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atmospheric, at the point of force main discharge. Refer Drawing No. STD-17 for the details of
rising main discharge manhole.
The primary consideration in the hydraulic design of rising mains is the pipe size, which provides
the required minimum velocity without creating excessive energy losses due to pipe friction. The
most economical size of rising main is determined on the basis of power costs required for
pumping, and capital investment costs of piping and equipment. In practice however, the size is
usually governed by the need to maintain minimum velocities at low flows to prevent deposition
of solids, and to develop sufficient velocity at least once a day to re-suspend any solids which
may have settled in the line. Rising mains shall be designed hydraulically with the use of the
modified Hazen- Williams formula as follows:
V = 143.534 x CR x R0.6575 x S 0.5525
Where,
V = velocity in m/s
CR = coefficient of pipe roughness = 1 for smooth pipes
R = hydraulic radius in metre, and
S = friction slope
(Velocity criteria for rising mains are based on the fact that suspended organic solids do not
settle out at a velocity of 0.6 m/s or greater. Solids will settle at velocities less than 0.3 m/s and
when sewage pumps are idle. However, a velocity of 0.75 to 1 m/s is generally adequate to
resuspend and flush the solids from the line. Rising mains serving pump stations, which are
designed to operate on an intermittent basis, will be sized to provide a minimum velocity of 1 m/s
at the peak discharge rate. Minimum pipe sizes should be 100 mm, (when sewage pumps are
used that has at least 50 mm solids passing capacity) so that clogging of the rising main is
minimized).
The material for rising main is discussed in Chapter -5, section 5.9. The design of rising mains
shall be similar to water lines in that thrust restraints and blocks shall be provided at bends and
tees. Also, expansion and contraction of the rising main through the slip joints would be planned
for. Air release valves would be provided at high points to prevent air locking and siphoning.
Vacuum valves would be provided as needed to admit air after a pumping cycle. Consideration
would also be given to cleanouts so that places where clogs may develop can be cleaned;
typically, at low spots or at changes in direction.
8.6 System Head Curve
One of the important parameter in design of pumping station shall be development of system
head curves, based on two elements; (1) the static head and (2) the friction head.
Static head is defined as the vertical lift of the fluid that the pump has to overcome. It is
assumed to be a constant head after the station is put into operation for a baseline of the
system head curve. It is defined as follows:
Static Head = Highest elevation opened to the atmosphere* minus the system’s low point**
(*This will typically be the pipe outlet. **All pumps off elevation (Suggestion: Use the average elevation between the
“lead pump on” and “all pumps off”. This will give the mid point of the pump operation range.)
Friction head: In a given system, the friction head will vary with the flow rate, as defined by the
following equation:
H = [L x (Q/CR)1.81 / (994.62 D4.81)]
H = frictional head loss, metre
L = length of pipe, metre
Q = flow in pipe, m3/s
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D = internal diameter of pipe, metre
CR = coefficient of pipe roughness = 1 for smooth pipes
In considering a pump to meet system needs, the operating point for the selected pump shall
coincide as closely as possible with the design flow and best efficiency point of the pump. Pump
efficiency is an important factor to consider in the selection process. Pump efficiencies vary
because of impeller design (vortex, semi-open, closed) and pump housing design (concentric or
convolute). These features would be considered in the pump selection process to give long term
service and reliability.
On selection of the pumps, the useful horsepower (HP) shall be determined which is defined as:
HP = 10 x (q) (TDH) /ηηηη
where, q = pumping rate (m3/s)
TDH = total dynamic head (m) at q
η = efficiency of motor (%)
The system head curve shall then be plotted on the pump performance curve for both single and
dual pump operations to determine the operating points of the system.
8.7 Wet Well Sizing
Wet wells are constructed at pumping stations for the purpose of storing sewage flows prior to
pump operation. The storage volume required depends upon the method of pump operation,
i.e., whether pumps are constant, adjustable or variable speed. In addition to providing
adequate storage volume, wet wells are designed to (1) allow for proper pump and level
controls, (2) maintain sufficient submergence of the pump suction inlet, (3) prevent excessive
deposition of solids, and (4) provide ventilation of incoming sewer gases. In smaller stations, bar
racks or comminuting devices may be installed within the wet well in order to reduce costs.
Overflows from wet wells are prohibited in all cases.
Wet well shall be sized so that the cycle time for each pump is not less than five minutes or that
the average cycle time shall not be more than 30 minutes. The shortest operating cycle occurs
when the inflow equals to ½ the pump discharge rate.
8.8 Mechanical and Electrical Aspects
Screens are provided at the entry point of sewage in to wet well for removal of floating material.
Screens are two in parallel, mechanical and manual type. Inlet channel to the wet well is
controlled with sluice gate. Instruments provided will be compatible with SCADA, if implemented
in future. Level switches and indicators will be provided for automatic start and stop operation
of pumps. Alarms will be provided for safe operation of station. Overhead crane of suitable
capacity will be provided (either electrically or manually operated).
HT panel with adequate capacities of VCB’S with protective relays shall be provided. LT panel
distribution board both for normal and emergency load shall be provided with adequate capacity
of ACB’S, MCCB’S. The control circuit shall be DC operated 12Volts. Motors up to rating of 7.5
KW shall be operated with DOL starters whereas all other motors shall be provided and operated
with star delta starters. To ensure availability of the power supply in the event of mains failure
the power supply shall be given through DG sets. It is proposed to install DG sets of 50% capacity
of total load. Adequate internal and external electrification work in and around the building shall
be provided. All HT /LT cables shall be of suitable grade with Aluminium conductor XLPE
extruded as per IS: 7098. The wiring in the building shall be done with FRLS copper wires.
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8.9 Other Features
Non-Return Valve: shall be provided in the rising main to prevent the back flow of sewage.
Gate valve: shall be provided on the rising main on the discharge side to close the flow of
sewage during maintenance, inspection and repair of the pump.
Air valve: shall be provided at all high points along the rising main.
Pressure gauge: shall be installed at the appropriate position to record delivery pressure.
Sewage level indicator: shall also be fitted in wet well to record the level of the sewage.
Washouts: For cleaning and maintenance purpose, the low points (in vertical alignment) shall be
provided with wash outs in the form of openings.
Access points: cleaning chamber shall be provided at about 200 m spacing along the rising main.
Pipeline protection: The rising main shall be having outside coating to protect from weathering
action / soil related corrosion.
Thrust Blocks: Rising main shall be securely anchored wherever, there is change in direction. The
design of thrust blocks shall be based on the safe bearing capacity of soil. The rising main shall
be checked for surge pressure as well.
Pumps: The sewage pumping stations shall be of single well (wet well only) type with
submersible pumps with 1 working for average flow, 1 for peak flow and 1 for ½ of average flow.
Geometry: The geometry of the pump stations shall be circular or rectangular, depending on the
configuration of pumps adopted for installation. Of course, a circular pump station is easy to
design and construct but may not be able to house the desired number of pumps. A rectangular
pump house is comparatively more adaptable to housing any number of pumps though its
construction is difficult.
8.10 Summary of SPS Design
Under this DPR, 13 sewage pumping stations are proposed to facilitate conveyance of sewage up
to the proposed treatment facilities. The detailed hydraulic design of pumping stations is placed
in Volume – III and typical general arrangement, detail & section are presented.in Drawing No.
STD-06, STD-07 & STD-08. The summary of design is given in Table 8.1.
Table 8.1 : Summary of Sewage Pumping Stations
Sr. No. Zone Identification Average Flow
(MLD)
Rising Main
Length (metre)
1 I SPS – A 1.10 30
SPS – B 3.37 30
SPS – C 8.23 930
SPS – D 14.87 1260
SPS – E 87.09 30
2 II SPS – A (Existing) 71.79 40
SPS – B 11.65 35
SPS – C 6.03 1205
SPS – D 8.11 1415
SPS – E 7.91 2155
SPS – F 29.76 840
3 III SPS – A 4.25 775
SPS – B 6.11 1280
***
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Design of Sewage Treatment Plant 9999
9.0 Design of Sewage Treatment Plant
9.1 General
Sewage originates predominantly from water usage by residential areas, commercial and
industrial units. Sewage flow fluctuates with variations in water usage (see chart below), which is
affected by various factors like community size, living standards, dependability and quality of
water supply, climate, water conservation practices and the extent of metering. Also the cost of
water and supply pressure along with degree of industrialization, affect the wastewater
generation. Large variations in sewage flow rates may occur within a community.
Understanding of the nature of sewage is essential for design of suitable sewage treatment
plants and the selection of effective treatment technology. Physical, chemical and biological
methods are used to remove contaminants from sewage. In order to achieve desired / statutory
levels of contaminant removal, a combination of procedures are used in the system, which are
classified as primary, secondary and tertiary sewage treatment. More rigorous treatment of
sewage includes the removal of specific contaminants as well as the removal and control of
nutrients. Natural systems are also used for the treatment of sewage in land-based applications.
0.00
0.50
1.00
1.50
2.00
2.50
3.00
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time in Hours
Flow Factor
Minimum
Peak Flow
Average Flow (ADWF)
The above chart reflects the typical domestic sewage flow generation pattern in a day. The curve shows a sharp rise between 6 to 9 hrs, which represents the peak flow. A similar pattern is observed during evening time between 17 to 20 hrs. The red band shows minimum flow generation, which is ½ to 1/3
rd of
average flow. The pink colour line denotes the average flow. The above daily flow pattern shall be applied for design of sewerage network of Raipur city.
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9.2 Sewage Characteristics
Sewage comprises a mixture of various types of liquid wastes from residential; public and
industrial places. Sewage contains 99.9% of water and 0.1% are solids that pose threat as they
are offensive in nature, undergo changes by bio-degradation cause nuisance and pollution.
Understanding of the nature of physical, chemical and biological characteristics of sewage is
essential in planning, design and operation of treatment and disposal facilities and in the
engineering management of environmental quality. The typical characteristics of domestic
sewage as reported in various literature and recommended for use in design of treatment plants
is presented in Table 9.1.
The important sewage
characteristics of interest
during STP design is the
BOD5 value, which has a
direct bearing on the
sizing of various units.
Literature survey related
to various municipal STPs
under NRCD projects
reveal that the BOD5
considered in design is in
the range of 180 mg/l to
225 mg/l. Data published
by CPCB with respect of
influent sewage
characteristics for STPs in
Delhi reveals the same
trend (refer Annexure-3).
The CPHEEO manual recommends 90 grams solids and 45 grams BOD as per capita per day
contribution in sewage. If the CPHEEO standards are adopted, then for this project, the BOD5
concentration works out as 416 mg/l. However, due to dilution effect and other wastes joining
sewage, the BOD5 concentration rarely rises beyond 250 mg/l. The wastewater analysis of drains
carrying sewage was carried out in Raipur city by the Chhattisgarh Environment Conservation
Board (CGECB), Regional Office, Raipur. The analysis reveals composition of a typical wastewater
flowing in open drains, having less BOD and high COD, which means pollution is being carried in
to the receiving waters. The results are placed at Annexure-3. The sewage characteristics at this
stage, for detailed design of STPs are being adopted as per Table 9.2.
9.3 Sewage Treatment Methods
As mentioned above, sewage
treatment methods are broadly
classified into physical, chemical and
biological processes. The unit
operations included in each category is
given in Table 9.3 below.
Table – 9.1: Typical Domestic Sewage Characteristics
Sr.
No.
Characteristics Range
(gram/cap/day)
Typical
value
1 pH 7 – 10 7 – 10
2 Colour grey, light brown -
3 Odour Soapy, oily -
4 BOD5 45 – 54 45
5 COD 1.60 – 1.90 BOD5 1.60 BOD5
6 Total solids 170 – 220 190
7 Suspended solids 70 – 145 100
8 Grease 10 – 30 10
9 Alkalinity 20 – 30 25
10 Chlorides 4 – 8 6
11 Total nitrogen 6 – 12 9
12 Total phosphorus 0.60 – 4.50 2.25
13 Micro-organisms (bacteria,
virus, coliforms, etc)
102 – 10
10 10
6
Table – 9.2: Sewage Characteristics Adopted For Design
No. Characteristics Value
1 pH 7.51
2 Appearance Blackish turbid
3 Odour Unpleasant
4 BOD5 250 mg/l
5 COD 500 mg/l
6 Total solids 450 mg/l
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Table – 9.3: Sewage Treatment Unit Operations and Processes
Sr. No. Unit Operations Processes
1 Physical
• Screening
• Grit removal
• Flow equalization
• Sedimentation
• Flotation
• Granular-medium filtration
2 Chemical • Chemical precipitation
• Adsorption
• Disinfection
• Dechlorination
• Other chemical applications
3 Biological • Activated sludge process (ASP)
• Trickling filters (TF)
• Rotating biological contactors (RBC)
• Pond stabilization / Aerated lagoon
• Fluidized aerobic bed reactor (FAB)
• Upflow anaerobic sludge blanket reactor UASB)
Physical unit operations still form the basis of most process flow systems for sewage treatment.
Commonly used physical units are screening, grit removal and sedimentation for which the
literature is widely available. Chemical treatment is normally required for industrial effluents,
whereas, disinfection may be adopted for municipal sewage, after biological treatment. Brief
comparison of biological units is presented hereafter.
9.3.1 Biological Treatment
Biological unit processes are used to convert the finely divided and dissolved organic matter in
wastewater into flocculent settleable organic and inorganic solids. In these processes, micro-
organisms, particularly bacteria, convert the colloidal and dissolved carbonaceous organic
matter into various gases and into cell tissue which is then removed in sedimentation tanks.
Biological processes are usually used in conjunction with physical and chemical processes, with
the main objective of reducing the organic content (measured as BOD, TOC or COD) and nutrient
content (notably nitrogen and phosphorus) of wastewater. Biological processes used for
wastewater treatment may be classified under five major headings, namely, (a) Aerobic
processes, (b) Anoxic processes, (c) Anaerobic processes, (d) Combined processes, and (e) Pond
processes.
These processes are further subdivided, depending on whether the treatment takes place in a
suspended-growth system or an attached-growth system or a combination of both (see
Annexure-4). In this section, the biological processes, including trickling filters, activated sludge
process, aerated lagoons, rotating biological contactors, stabilization ponds, fluidized Aerated
Bed (FAB), Upflow Anaerobic Sludge Bed (UASB), Membrane Bio Reactor (MBR), Moving Bed
Biofilm Reactor (MBBR) and Sequencing Batch Reactor (SBR) is discussed.
9.3.1.1 Activated Sludge Process
The activated sludge process is an aerobic, continuous flow system containing a mass of
activated micro-organisms that are capable of stabilizing organic matter. The process consists of
delivering clarified wastewater, after primary settling, into an aeration basin where it is mixed
with an active mass of microorganisms, mainly bacteria and protozoa, which aerobically degrade
organic matter into carbon dioxide, water, new cells, and other end products. (The bacteria
involved in activated sludge systems are primarily Gram-negative species, including carbon
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oxidizers, nitrogen oxidizers, floc formers and non-floc formers, aerobes and facultative
anaerobes. The protozoa, for their part, include flagellates, amoebas and ciliates). This process
is based on suspended growth system.
An aerobic environment is maintained in the basin by means of diffused or mechanical aeration,
which also serves to keep the contents of the reactor (or mixed liquor) completely mixed. After a
specific retention time, the mixed liquor passes into the secondary clarifier, where the sludge is
allowed to settle and a clarified effluent is produced for discharge. The process recycles a
portion of the settled sludge back to the aeration basin to maintain the required activated
sludge concentration (see flow diagram). The process also intentionally wastes a portion of the
settled sludge to maintain the required solids retention time (SRT) for effective organic removal.
Control of the activated sludge process is important to maintain a high treatment performance
level under a wide range of operating conditions. The principal factors in process control are the
following:
� Maintenance of dissolved oxygen levels in the aeration tanks;
� Regulation of the amount of returning activated sludge;
� Control of the waste activated sludge.
The main operational problem encountered in a system of this kind is sludge bulking,
which can be caused by the absence of phosphorus, nitrogen and trace elements and
wide fluctuations in pH, temperature and dissolved oxygen (DO). Bulky sludge has poor
settleability and compactibility due to the excessive growth of filamentous micro-
organisms. This problem can be controlled by chlorination of the return sludge.
9.3.1.2 Trickling Filter
It is aerobic attached growth biological treatment process used for the removal of organic
matter from wastewater. It consists of a bed of highly permeable medium to which organisms
are attached, forming a biological slime layer and through which wastewater is percolated. The
filter medium usually consists of rock or plastic packing material. The organic material present in
the wastewater is degraded by adsorption on to the biological slime layer. In the outer portion
of that layer, it is degraded by aerobic micro-organisms. As the micro-organisms grow, the
thickness of the slime layer increases and the oxygen is depleted before it has penetrated the
full depth of the slime layer. An anaerobic environment is thus established near the surface of
the filter medium. As the slime layer increases in thickness, the organic matter is degraded
before it reaches the micro-organisms near the surface of the medium. Deprived of their
external organic source of nourishment, these micro-organisms die and are washed off by the
flowing liquid. A new slime layer grows in their place. This phenomenon is referred to as
‘sloughing’.
After passing through the filter, the treated liquid is collected in an under drain system, together
with any biological solids that have become detached from the medium (see flow diagram). The
collected liquid then passes to a settling tank where the solids are separated from the treated
waste-water. A portion of the liquid collected in the under drain system or the settled effluent is
Influent Bar Screens Grit Chamber PST Aeration SST
Screenings Grit Sludge Recycle
Waste Cl2
Flow Diagram for typical processes units in Activated Sludge Process
Waste
Effluent
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Bar Screens Grit PST SST
Screenings Grit Sludge RBC Unit
Effluent
Flow Diagram for typical processes units in Rotating Biological Contactors
Influent
Motor drive
recycled to dilute the strength of the incoming waste-water and to maintain the biological slime
layer in moist condition.
9.3.1.3 Rotating Biological Contactors
A rotating biological contractor (RBC) is an attached-growth biological process that consists of
one or more basins in which large closely spaced circular disks mounted on horizontal shafts
rotate slowly through wastewater (see flow diagram). The disks which are made of high-density
polystyrene or polyvinyl chloride (PVC) are partially submerged in the wastewater, so that a
bacterial slime layer forms on their wetted surfaces. As the disks rotate, the bacteria are
exposed alternately to wastewater, from which they adsorb organic matter, and to air, from
which they absorb oxygen. The rotary movement also allows excess bacteria to be removed
from the surfaces of the disks and maintains a suspension of sloughed biological solids. A final
clarifier is needed to remove sloughed solids. Organic matter is degraded by means of
mechanisms similar to those operating in the trickling filters process. Partially submerged RBCs
are used for carbonaceous BOD removal, combined carbon oxidation and nitrification, and
nitrification of secondary effluents.
In general, RBC systems are divided into a series of independent stages or compartments
by means of baffles in a single basin or separate basins arranged in stages.
Compartmentalization creates a plug-flow pattern, increasing overall removal efficiency.
It also promotes a variety of conditions where different organisms can flourish to varying
degrees. As the wastewater flows through the compartments, each subsequent stage
receives influent with a lower organic content than the previous stage; the system thus
enhances organic removal.
9.3.1.4 Aerated Lagoon
An aerated lagoon is a basin between 1 m to 4 m in depth in which wastewater is treated either
on a flow-through basis or with solids recycling. The microbiology involved in this process is
similar to that of the activated sludge process. However, differences arise because the large
surface area of a lagoon may cause more temperature effects than are ordinarily encountered in
PST Trickling Filters SST
Screenings Grit Sludge Recycle
Waste Cl2
Influent
Bar Screens
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conventional activated sludge processes. Wastewater is oxygenated by surface, turbine or
diffused aeration. The turbulence created by aeration is used to keep the contents of the basin
in suspension. Depending on the retention time, aerated lagoon effluent contains approximately
one third to one half the incoming BOD value in the form of cellular mass. Most of these solids
are removed in a settling basin before final effluent discharge.
9.3.1.5 Stabilization pond
A stabilization pond is a relatively shallow body of wastewater contained in an earthen basin,
using a completely mixed biological process without solids return. Mixing may be either natural
(wind, heat or fermentation) or induced (mechanical or diffused aeration). Stabilization ponds
are usually classified, on the basis of the nature of the biological activity that takes place in
them, as aerobic, anaerobic, or aerobic-anaerobic (facultative). Aerobic ponds are used primarily
for the treatment of soluble organic wastes and effluents from wastewater treatment plants.
Aerobic-anaerobic (facultative) ponds are the most common type and have been used to treat
domestic wastewater and a wide variety of industrial wastes.
Anaerobic ponds, for their part, are particularly effective in bringing about rapid stabilization of
strong concentrations of organic wastes. Aerobic and facultative ponds are biologically complex.
The bacterial population oxidizes organic matter, producing ammonia, carbon dioxide, sulfates,
water and other end products, which are subsequently used by algae during daylight to produce
oxygen. Bacteria then use this supplemental oxygen and the oxygen provided by wind action to
break down the remaining organic matter. Wastewater retention time ranges between 15 and
40 days. This is a treatment process that is very commonly found in rural areas because of its low
construction and operating costs. A typical flow diagram for stabilization ponds is given below.
9.3.1.6 Fluidized Aerobic Bed Reactor (FAB)
FAB is a fixed-film reactor column that fosters the growth of microorganisms on a hydraulically
fluidized bed of media. The media is selected for greatest assurance of producing a low-
concentration effluent. The fluidized media provides an extremely large surface area on which a
film of microorganisms grows and produces a large quantity of biomass in a small reactor
volume. The biological process inside the FBR completely destroys the organic matter and waste
Bar Screens Aerated Lagoon SST
Screenings
Sludge
Return
Cl2
Effluent
Flow Diagram for typical processes units in Aerated Lagoons
Influent
Bar Screens Stabilization Solids Separation
Screenings
Cl2
Effluent
Flow Diagram for typical processes units in Stabilization Ponds
Influent Chlorine
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byproduct generated from the biodegradation is a small volume of excess bio-solids. These
solids are removed from the system on a continuous basis.
9.3.1.7 Upflow Anaerobic Sludge Blanket
Anaerobic granular sludge bed technology refers to a special kind of reactor concept for the
"high rate" anaerobic treatment of wastewater. The concept was initiated with upward-flow
anaerobic sludge blanket (UASB) reactor. A scheme of a UASB is shown in flow diagram.
Wastewater is distributed into the tank at appropriately spaced inlets. The wastewater passes
upwards through an anaerobic sludge bed, where the microorganisms in the sludge come into
contact with organic matter. The sludge bed is composed of microorganisms that naturally form
granules (pellets) of 0.5 to 2 mm diameter that have a high sedimentation velocity and thus
resist wash-out from the system even at high hydraulic loads. The resulting anaerobic
degradation process typically is responsible for the production of gas (e.g. biogas containing CH4
and CO2). The upward motion of released gas bubbles causes hydraulic turbulence that provides
reactor mixing without any mechanical parts. At the top of the reactor, the water phase is
separated from sludge solids and gas in a three-phase separator (also known the gas-liquid-
solids separator). The three-phase-separator is commonly a gas cap with a settler situated above
it. Below the opening of the gas cap, baffles are used to deflect gas to the gas-cap opening.
9.3.1.8 Membrane Bio Reactor (MBR)
It is a Combination of an activated sludge process and membrane separation and can maintain
the activated sludge concentration at a high-level in the reaction tank without use of a
sedimentation tank for separation of liquids mixed with the activated sludge. Yield of the treated
water at a higher quality is achieved, as well as the space and operation costs are relatively less.
Practically all suspended solids can be removed and bacteria-free treated water produced. The
sludge concentration and hydraulic loading rates are considerably higher than in conventional
treatment.
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9.3.1.9 Moving Bed Biofilm Reactor
The Moving Bed Bio-reactor (MBBR) is an aerobic Attached Growth Process which uses
cylindrical shaped polyethylene carrier elements for biological growth. The moving media
increases the contact time between the bacteria and the organics. Since the media has high
porosity it provides large surface area for bacteria to attach and grow. MBBR does not require
any return activated sludge flow or backwashing. It has excellent characteristics for BOD/COD
removal and nitrification in all types of wastewaters. It is compact and requires comparatively
lesser space than the conventional system.
9.3.1.10 Sequencing Batch Reactor (SBR)
It is a fill and draw system. Involves a single, complete mix reactor in which all steps of treatment
occurs. MLSS remain in the reactor during all cycles, thereby eliminating the need for a separate
clarifier. Process is simplified, final clarifiers and return activated sludge pumping are not
required. Operation is flexible and nutrient removal can be accomplished by operational
changes. High peak flows can disrupt the operation unless accounted for in the design, batch
discharge may require equalization and high maintenance skills are some of the disadvantages of
the process.
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9.4 Sewage Treatment Plant Design Considerations
The objective of providing sewage treatment plant (STP) is to treat the sewage, collected from
the various residential, commercial and institutional establishments, to achieve the pollution
control standards with respect of the area under consideration. There are many parameters
which require careful and judicious selection before setting off for the actual design of STP.
These parameters as mentioned hereunder shall be appropriately utilized during detailed design
stage.
9.4.1 Planning Considerations
Site selection: Selection of the STP site shall be based on careful consideration of the land use
and development pattern, social, environmental and engineering constraints. All possible STP
sites shall be fully evaluated on the basis of topography, environmental impacts and economics
of sewerage system. Following basic principles shall be considered during site selection for STPs.
� The STP shall be located at low elevation in order to have gravity flow.
� The site shall have all weather access road.
� The STP site shall be away from residential areas and shall have a buffer area for future
expansion.
� The site shall be near to a large water body (but outside HFL line) or irrigable land to accept
treated effluent.
� The site shall have good ground support for foundation of structures.
� The site shall have moderate slope and free from archaeological presence.
Issues to be investigated before final selection include topography, drainage, surface/ground
water, soil type, wind direction, temperature, rainfall, wildlife habitat, ecosystem and local land
use.
Layout of units: Plant layout is the physical arrangement of designed treatment units on the
selected site. Careful consideration is required for location of units, connecting pipes, access
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roads, parking, lighting, safety measures, administration building and maintenance workshop.
Efforts shall be made during layout preparation to;
� Enhance the attractiveness of STP site.
� Fit the operational needs of the process.
� Suit the maintenance need of operation personnel.
� Minimize construction and operational cost.
� Offer flexibility for future expansion of plant.
� Landscaping of the site in harmony with surrounding environment.
9.4.2 Design Considerations
Sewage flow: refer Chapter -4
Design period: It is anticipated that minimum 1 to 2 years shall be consumed to plan, design and
construct a sewage treatment plant as envisaged under the project of this magnitude. The initial
year is the year when construction is completed and the initial operation begins. The design year
is the year when the facility is expected to reach its full designed capacity. Design period is
chosen with following factors in mind;
� Useful life of treatment units
� Ease / difficulty in expansion
� Cost of construction and availability of funds
In a STP, conduits, channels and appurtenances are designed for the ultimate year, whereas the
treatment units, process equipments, pumps, etc, are designed for shorter periods to avoid
oversized construction. In such cases, adequate space is left for future expansion of the STP.
Accordingly design period is divided in to staging period. Considering the criteria of useful life of
machinery and equipment in STPs, 15 years staging period would be more appropriate. Hence
with year 2012 reckoned as base year, the first stage would be year 2027 and the second stage
would be 2042, which would be the design horizon of project.
Sewage characteristics: refer section 9.1.
Hydraulic profile: It is the graphical representation of hydraulic grade line through the STP. The
total available head at STP site is the difference between water surface elevation in interceptor
sewer and receiving water at HFL. If the total available head is less than the head loss through
the plant, gravity flow cannot be achieved in between units. In such cases pumping is needed to
raise the head so that gravity flow can occur. It is acknowledged fact that a good design is the
one where head loss through STP is in the range of 3 m to 5 m. Such plants have been found
economical in construction and operation.
Effluent standard: The treated sewage effluent from STP is normally governed by some statutory
regulations regarding its constituents before discharge in to surrounding environment. As per
GSR 801 (E), EPA, 1986, dated Dec. 31, 1993, government has promulgated standards for
effluent disposal known as ”General Standards for Discharge of Environmental Pollutants”. Out
of the 33 parameters listed, only 12 parameters of concern to domestic sewage disposal are
presented in Annexure-5.
9.4.3 Process Considerations
Degree of treatment: The degree of treatment required is based on the influent (raw sewage)
characteristics and the effluent standards required to be met. This project aims at achieving
standard for industrial reuse applications and /or disposal in to inland water body. Also there is a
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potential for application of effluent for irrigation since the land along river valley is subjected to
agriculture. This aspect is dealt in detail in Volume - III.
Equipment selection: Every STP involves installation of manufactured equipments and materials.
In fact many design details are often governed by the dimensions and installation requirements
of the selected equipments. It becomes necessary to select the treatment processes and the
corresponding type of equipment for achieving the desired results. This requires a careful study
of the equipment catalogs in advance and close working with equipment manufacturer or
supplier.
Process requirement (land, power, maintenance, skilled staff): Mostly the domestic sewage
treatment is based on biological processes. These process units requires power for sustaining
their activities and concentration, for which at times skilled manpower is required to monitor
the process. Processes with minimum energy and manpower requirement are preferred.
Modular expansion of units (phasing): While planning a sewage treatment plant, consideration is
always given to phasing of unit processes in the system. Not all the flow is taken into single unit
for design. This is because the flows are developed gradually and there becomes a need to
expand the capacity of treatment units. In such cases units which can be easily replicated are
given choice.
9.4.4 Environmental Considerations
Odor problem: Almost every STP is associated with odour problem. Due to presence of large
quantum of organic matter in sewage, and its subsequent change in chemical composition, there
is release of noxious gases (particularly H2S) leading to bad odour surrounding the treatment
premises. The release of digested sludge for further drying on sludge drying beds release
trapped gases and thus creates an unpleasant atmosphere in the nearby vicinity. This causes an
environmental detriment for the neighboring community. The setting of treatment with respect
to the predominant wind direction plays a key role in minimizing the effect of odour.
Aesthetics and landscaping: A good design contemplates provision for landscaping and
aesthetics of the structures and buildings to be provided in the premises. Landscaping improves
the image of utility, as normally treatment plants are perceived as places of stink and odor.
Surrounding pollution (water): In STPs, at times the sewage is required to bypass the treatment
processes for direct disposal in to receiving water bodies or to the holding ponds, on account of
major shut down in the plant units for O & M. Frequent occurrences of such events has the
potential to pollute the surroundings, thus causing damage to environmental components.
Modular design of multiple units can reduce such hazards, since temporary overloading of
process units can be practiced to certain extent, to avoid direct bypass of raw sewage.
Effluent reuse: After treatment, effluent is either reused or discharged into the environment
(water body or land application). Treated effluent (adhering to effluent standards) from
municipal STPs can be reused as a reliable source of water for agricultural irrigation, landscape
irrigation, industrial recycling and reuse, groundwater recharge, recreational uses. If not reused,
treated effluent is commonly discharged into a water body and diluted. As mentioned earlier the
environmental regulations, guidelines and policies ensure acceptable discharge of effluent. The
flow projections revel that under this project about 189 Mld (90% of 210 Mld) treated effluent
would be available for reuse at immediate stage (year 2027) and shall gradually increase to 264
Mld at ultimate design stage (year 2042).
9.4.5 Social Considerations
Land acquisition: Land is required for construction of new STPs and their appurtenances. The
type of treatment process envisaged and site selection criteria govern the quantum of land
acquisition. The quantum of land proposed for acquisition also covers the future area
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requirements on account of plant expansion and buffer zone. In most cases, outskirts (away
from habitation) of the city are chosen for location of STP site, where water body is available.
Usually the low lying areas adjacent to water body are agricultural lands falling in the flood
plains of the water body. Acquisition of such agricultural lands relate to the applicable laws of
land acquisition. Special consideration is required for land owners who belong to under
privileged society and tribal community.
Rehabilitation and resettlement: A good rehabilitation package works wonder for the
construction of STP as it reduces the cost and time overrun. It is ideal to complete the
rehabilitation process for land acquisition affected people before the construction begins, may
be during tendering process, otherwise crucial time is lost in convincing the protesting land
owners before land acquisition.
9.4.6 Economic Considerations
Capital cost: During the design of sewage treatment plant, capital cost consideration is an
integral part of design. Capital cost is considered on the basis of hydraulic sizing.
Annual operation and maintenance cost: This is the recurring cost envisaged every year to keep
the planned treatment system in reasonable working condition (performance wise). Normally
during treatment selection O&M cost is annualized for life period of plant E&M equipments. This
cost is represented as percentage of capital cost.
9.5 Sewage Treatment Plant
All over the world, Governments are increasingly realizing a need for providing and maintaining
the urban environmental infrastructure facilities in order to keep the urban environment clean
and healthy which essentially is the traditional function of the Local Governments. However, the
Local Governments in India, have not been able to fulfill the promise of adequate civic
infrastructure to their rapidly increasing number of citizens mainly due to lack of institutional
capabilities and financial resources. As a result most of the cities have grown into overcrowded
and ill-equipped settlements with a highly polluted environment prone to frequent epidemics.
The sewage from domestic and industrial sources in the cities has been polluting rivers and other
water bodies situated nearby.
Through section 7.3 and 7.4, it is concluded that, the sewage conveyance system would
ultimately lead to three different locations in the City. Separate presentation of each zonal STP
would form repetitive analysis, therefore, a unified analysis is presented hereunder to
understand the techno-economics. After the recommendations are formulated, the STPs are
designed for their respective zonal sewage flow and presented in Volume - III. The total quantity
of sewage generated up year 2042 is estimated at 296.14 Mld. The current estimates reveal
sewage generation at 109.59 Mld (commissioning year 2012) and intermediate flow up to year
2027 is estimated at 208.81 Mld. The zone wise capacity of STPs based on sewage generation is
presented in Table 9.4.
Table 9.4 : Zone wise STP Capacity, MLD (Average Flows)
Intermediate Year 2027 Ultimate Year 2042 Sr.
No.
Zone
Sewage
Flow
Infiltration Total
Sewage Flow
Sewage
Flow
Infiltration Total
Sewage Flow
1 I 64.96 1.86 66.82 90.52 1.86 92.37
2 II 66.91 1.44 68.35 93.23 1.44 94.67
3 III 76.94 1.89 78.83 107.21 1.89 109.10
4 TOTAL 208.81 5.18 213.99 290.96 5.18 296.14
Note: Infiltration is used for hydraulic sizing of gravity sewer pipes, it is not considered for sizing of STPs
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There are number of treatment technologies that are applied for sewage treatment in India and
elsewhere. The technologies that have been used are mostly biological and have their own
merits and demerits. In order to arrive at the best feasible sewage treatment option from a
techno-economic point of view, broadly following criteria has been adopted for selection of the
sewage treatment options for evaluation.
� Removal efficiencies of the treatment system to be sufficient enough to meet industrial reuse
and effluent discharge standards;
� The treatment technology should be simple to construct, easy to operate and have low
operation and maintenance cost over a longer run;
� The treatment technology should have low cost on Life Cycle Analysis; and
� The treated effluent is reused effectively for industrial, irrigation and other non potable
purposes.
Based on the above guidelines, and subsequent to recommendations of RMC on technology
selection, only two treatment technologies considered for techno-economic evaluation are as
follows:
1. Activated Sludge Process and
2. Sequential Batch Reactor.
9.5.1 Performance Evaluation of SBR and ASP
The selection and design of wastewater treatment facilities is greatly dependent on the
performance of various units under design conditions and peak loading, apart from the costs
associated with treatment processes, land requirements and sludge handling / disposal. The
data reported in literature, for both technologies is presented in Table 9.5.
Table – 9.5: Performance of ASP and SBR Technologies
Parameter Percent removal (%)
ASP SBR
BOD 85 – 92 90 – 95
Coliforms 60 – 90 65 – 99
Nutrients 30 – 45 90 – 95
In Activated Sludge Process (ASP), the biological culture present in aeration tank (in suspension)
referred to as ‘mixed liquor’ carries out the conversion of organic matter and nutrients utilizing
oxygen to produce new bacterial cells. These bacteria further convert organic matter to CO2,
water, ammonia. The organic matter removal efficiency is the function of level of oxygen present
and concentration of mixed liquor (2000 to 3000 mg/l).
The incorporation of a biological SELECTOR in the front end of the SBR Systems distinguishes it
from ASP. The raw effluent enters the SELECTOR zone, where ANOXIC MIX conditions are
maintained. Part of the treated effluent along with return sludge from the aeration basin is
recycled in here, using RAS pumps. As the microorganisms meet high BOD, low DO condition in
the SELECTOR, natural selection of predominantly floc-forming microorganisms takes place. This
is very effective in containing all of the known low F/M bulking microorganisms, eliminates
problems of bulking and sludge foaming. This process ensures excellent settling characteristics of
the bio sludge. SVI of treated effluent of less than 120 is achieved in all seasons. Also due to the
anoxic conditions in the SELECTOR zone, De nitrification and Phosphorous removal occurs in case
the Ammonical Nitrogen and Phosphorous levels are high in the sewage. The removal efficiency
of BOD due to controlled environment is more than 95%.
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9.5.2 Techno-Economic Evaluation of ASP and SBR
The main purpose of the techno-economic evaluation ASP and SBR is to evolve a preferred
option, which is sustainable from a long term perspective, and fits well within the effluent
discharge standards stipulated in the guidelines of CPHEEO Manual and State / Central Pollution
Control Board. Considering the scarcity of water in future and environmental concerns, it is
prudent to adopt a technology which can facilitate to achieve the stringent wastewater disposal
standards with out additional cost burden of retrofitting or tertiary treatment requirements.
Raipur being a Capital City is witnessing fast growth in terms of industrial activities and water
demand. The treatment technology selected hereunder will act as a potential source for
augmenting water demand for industrial purposes. World over, technologies that are producing
water fit for industrial reuses are being preferred. The other aspect is the relative cheap pricing
of reuse water for industrial applications as compared to fresh water.
Activated Sludge Process: The conventional Activated Sludge Process for sewage treatment has
wide application record in India / abroad. It is robust in nature, high removal efficiencies of BOD,
capacity to take shock loads testifies its selection for evaluation. Its removal efficiencies for BOD
and TSS are in the range of 85 to 95%.
Sequential Batch Reactor: Sewage treatment by this technology is excellent as it does not
require any tertiary treatment. It yields a very high quality effluent readily usable for industrial
applications. The capital cost is at par with other mechanized processes and power requirement
is controlled because of automation. In areas of high land acquisition cost, it is a good option as
area required is 1/3rd
of ASP. The plant is fully process controlled and hence most efficient.
A brief comparison on advantages and disadvantages of the above technologies is presented
below in Table9.6.
Table – 9.6: Comparison of ASP and SBR Technologies
Sr.
No.
Treatment
Technology
Advantages Disadvantages Remarks
1 Activated
Sludge Process
• Moderate efficiency • High land requirement
• Difficult in operation
• High capital cost
• High O&M cost
• High sludge generation
• Bulking of sludge
• No nutrients removal
Difficult operation
under variable flows
and tertiary treatment
required for industrial
reuse of treated
effluent
2 Sequential
Batch Reactor
• Less land requirement
• Time controlled operations
• Excellent Efficiency
• Nutrients removal
• Less power required
• No tertiary treatment
required
• Less and stable sludge
generation
• No sludge bulking
• Power generation
• Low O&M cost
• High capital cost (similar
to ASP)
• Discontinuous influent
feeding and effluent
discharge
• The variable level and
volume
• Complex moving
equipment
Best suited when land
available is less and to
met the stringent
effluent discharge
regulations
As ASP and SBR plants have dedicated volumes for biological treatment and sedimentation. Only
very limited flexibility is available in ASP in-case that predicated design flows or loadings deviate
from the reality (sludge bulking). ASP plant cannot operate with in basin BIORATE control which
leads to increased operation cost, reduced treatment efficiency and potential of over aeration of
the activated sludge.
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ASP plants show extreme sensibility against peak flow and loadings. Peak flow transfers
activated sludge into the final settling tanks and finally into the effluent. Peak loadings show up
in the effluent without delays as ASP plants are typically designed as completely stirred tank
reactors (CSTR).
ASP need relatively high amounts of recirculation flows which make the design of effective
SELECTOR basins impossible. The high initial F/M loading can not be achieved therefore ASP
plants show a tendency to produce bulking sludge.
ASP plants need a high amount of Electro-mechanical equipment such as pumps, mixing devices,
scraping bridges etc. which are subject to maintenance, repair and replacement. SBR plant
avoids these disadvantages by a reliable and simple automation and control system with
BIORATE control.
ASP plants cannot detect toxicity of influent until effluent measurements are carried out. At the
time toxic influents are reaching the effluent the conventional ASP biomass is either damaged or
destroyed already. SBR plant detects toxicity at the beginning of the cycle and in this case not
allow other basins to be filled.
In order to arrive at the best feasible sewage treatment option for Sewage Treatment Plants
(STP) at Raipur, from a techno-economic point of view, an evaluation of ASP and SBR
technologies is presented with respect to the following major criteria:
� Treatment Levels (suitability to meet discharge standards);
� Land area requirement;
� Process energy requirement;
� Capital costs;
� Operation and Maintenance costs; and
� Life Cycle Cost Analysis.
Treatment Levels: Of the technologies presented above, the overall treatment level achieved in
terms of BOD removal varies from 85% to 95%. With an incoming BOD of 250 mg/l (COD: 250
mg/l x 2 = 500 mg/l) the effluent BOD after biological treatment is expected around 10 to 30
mg/l. Similarly the suspended solids are expected to be less than 50 mg/l. The Faecal coliforms
levels in the final effluent would be less than 1000 MPN/100ml. Since the application of treated
effluent is considered for industrial reuse, only SBR technology is capable of meeting the desired
treatment levels. However, both ASP and SBR are both capable to produce effluent for land
applications.
Land requirement: The land requirement for a new treatment plant includes the total area
needed for units, equipments and peripherals (pumps, controls, access areas, etc.). Additionally,
a 6 m perimeter around each unit is assumed to have comfortable working area. Literature has
reported land requirements for various technologies on per capita basis. The land requirement
for STPs is worked out with respect to ultimate population of year 2042 (sewage generation of
303.55 Mld) and is presented in Table9.7 below.
Table- 9.7: Land requirement for ASP and SBR
Land Required (296.14 Mld) Rank Process
(ha/Mld) Hac
1 Sequential Batch Reactor (SBR) 0.10 29.70
2 Activated Sludge Process 0.25 74.25
For ultimate year 2042, flow generation Source: Practical Handbook on PHE, Er. G. S. Bajwa, 2003
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As seen from above table, SBR technology based STP requires least area at the rate of 0.1
ha/Mld as compared to 0.25 ha/Mld for ASP. This is because, there are no primary and
secondary clarifiers in the SBR plant configuration, which means less area occupied. On the basis
of land rates (approximate), prevailing in RMC jurisdiction, the cost of land required for various
technologies is presented graphically below. For ASP and SBR technological options, land
requirement and cost of land is presented in Table 9.8.
Table – 9.8 : Land Cost For ASP and SBR STPs (Ultimate stage – 2042 YEAR)
Type Land requirement Zone – I Zone – II Zone – III
Flow 91 Mld 94 Mld 109 Mld
Rate (Rs/hac) 1.0764 Lakhs
Total (hac) 22.75 23.50 27.25
Available Land (hac) 0 0 0 ASP
Total Cost (Rs.) Lakhs 24.49 25.30 29.33
Total (hac) 9.10 9.40 10.90
Available Land (hac) 0 0.0 0 SBR
Total Cost (Rs.) Lakhs 9.80 10.12 11.73
Note: Cost is for ultimate land requirement (year 2042) and exclusive of any additional R&R benefits.
Approximate Cost obtained from discussion with RMC officials, Raipur.
Energy requirement: Energy (power) is required for functioning of mechanical process
equipments installed in the STP. The energy consuming units are PST, SST, biological reactor
(aerators), internal pumping, etc. Literature and design computations has reported process
energy requirement of ASP and SBR technologies in use and a comparison is presented below in
Table 9.9.
Table-9.9: Energy Required For ASP and SBR Technologies
Rank Process Energy required
Kw-hr/day/Mld
1 Sequential Batch Reactor (SBR) 166
2 Activated Sludge Process 200
In ASP, energy is required to oxygenate the mixed liquor in aeration tank as well as keep it in
suspension. For this purpose aerators are used. In SBR energy is required to supply oxygen to
microbes, the energy consumption is less as compared to ASP because, the plant operations are
fully controlled on the basis of real time information fed to the plant operators.
Capital cost: The capital cost involved in a typical STP comprise cost of site development,
construction of various treatment units, electrical and mechanical equipments, instrumentation,
pumps and piping, infrastructure services, buildings, green belt, etc. The cost also includes initial
startup cost of the plant (i.e. seeding of reactors, etc.). Based on published literature survey,
personal communications with leading contractors, ongoing executions of similar STP
technologies and past experience, the cost for ASP and SBR treatment technologies is presented
in Table 9.10 below. Mostly the costs are presented as Rupees per Mld sewage treated (capacity
of plant).
Table-9.10: Capital Cost for STPs with Various Biological Processes
Cost (Lakh Rs.) Rank Process
Per Mld (Ultimate 296 Mld)
For 209
Mld*
1 Activated Sludge Process 95 28120 19855
2 Sequential Batch Reactor (SBR) 98 29008 20482
* Intermediate year 2027, the above capital costs are excluding the land cost
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The above costs are presented for two cases, namely ultimate requirement and intermediate
requirement. ASP and SBR are almost identical in cost though the civil component is less in SBR.
Operation & Maintenance cost: The technological options under consideration require various
mechanical equipments (pumps, aerators) for aiding the biological process. These equipments or
their parts are in continuous touch with sewage and due to corrosive nature / contents of
sewage, they get clogged and/or are damaged. This needs periodic maintenance to upkeep their
useful life and utility in the process. The piping, valves, gasholders, etc, need periodic
maintenance for efficient working of the reactors. In ASP large machinery is at work that
requires O&M. In mechanized processes category SBR requires minimum O&M because the
plant is working under controlled processes. On the basis of literature and experience in Indian
conditions, for various technologies, the annual O&M percentage cost with respect to capital
cost (for intermediate stage of year 2027) is presented in Table 9.11.
Table-9.11: O&M Cost for STPs with SBR & ASP
O& M cost
Rank Process % (Lakh Rs.)*
1 Sequential Batch Reactor (SBR) 4 819.28
2 Activated Sludge Process 8 1588.4 * Intermediate year 2027
For the intermediate stage of year 2027, a total of 209 Mld sewage would be available for
treatment. The capital cost and annual O&M cost along with capitalized O&M cost (for 15 years
with 12% interest) for ASP and SBR technologies is computed and presented in Table 9.12 below.
Table-9.12: O&M Cost for ASP and SBR STPs (Intermediate Stage – 209 MLD)
Cost (Lakh Rs.) Rank Process
Capital O&M
Per
year
Capitalized
O&M - 15
yrs
Total
(i) (ii) (iii) (i+iii)
1 Sequential Batch Reactor (SBR) 19855 819.28 5580.01 26062.01
2 Activated Sludge Process 20482 1588.40 10818.38 30673.38
9.5.3 Total Cost of STP
Using the computations of land cost, capital investment cost and annualized O&M cost for the
selected options, a final ranking is presented in Table 9.13.
Table 9.13 : Total Cost For STPs (Intermediate Stage)
Cost (Lakh Rs.) Rank Process
Land Capital Capitalized O&M
for 15 yrs
Total
1 Sequential Batch Reactor (SBR) 31.65 19855.00 5580.01 25466.66
2 Activated Sludge Process 79.12 20482.00 10818.38 31379.5
As seen from the above comparison, SBR technology is cheaper than Activated Sludge Process
and becomes the economical option considering cost of land, capital investment and annualized
O&M for 15 years tenure. The life cycle analysis of ASP and SBR plants for all three zones is
presented in Annexure – 6 and the hydraulic design of SBR plants is given in Volume – III.
9.5.4 Recommendation on Treatment Technology
On the basis of information presented in section 9.4, a summary of technical and economical
comparison is presented in Table 9.14.
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Table 9.14: Comparison of ASP and SBR
Sr.
No
.
Parameters ASP SBR
PERFORMANCE PARAMETERS
1 Effluent
BOD5, mg/l
< 30
< 5
2 Effluent SS,
mg/l < 50 < 10
3
Faecal
coliforms,
MPN/100ml
> 1000 < 1000
TECHNO-ECONOMIC PARAMETERS
4
Land
requirement,
ha/Mld
0.25 0.10
5
Energy
requirement,
kw-hr/Mld/d
200 166
6 Capital cost,
Lakh Rs. /Mld 20995.00 21658.00
7 O&M cost,
Lakh Rs./Mld 7.60 3.92
OTHER PARAMETERS
8
Reuse of
treated
effluent for
irrigation
Suitable
Suitable
9
Operational
risk, loss of
efficiency due
to long power
cuts
High Medium
10 Environmenta
l Problems Moderate Minimum
11 Maintenance
requirement High Low
12
Sludge
Disposal
requirement
High Medium
In view of above parameters, their related importance in the comparison of alternative
treatment technologies, for the present project, following comments are presented;
� Land Availability
Raipur city is densely populated in the core area, and outgrowth on the fringes is expected in the
years to come. Therefore at this stage it is possible to earmark the land requirement for ultimate
stage STP capacity. Some land is available at the existing, now defunct Oxidation Ponds. This
area is proposed to be utilized for new STP on north side of the city in Rawabhata area (i.e., for
Zone-II). For this stage, it is assumed that land for all the three STPs for Zone-I, II and III would
require 30.40 hac land (to be acquired after verification of ownership).
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Final Comment: (refer to Table 9.14) Since Raipur city is expected to have a facelift in future,
and keeping pace with time a technology with excellent treatment efficiency and very less land
requirement would suit most. Hence a Sequential Batch Reactor STP is finally recommended
for Raipur. For yielding better results, the RMC has to gear for the arrangements (like power,
O&M inputs) in long run to convert it in a model treatment facility in state.
9.6 Disposal of Treated Effluent
The proper disposal of treated effluent has become an essential part of planning and designing
STP. Some of the methods adopted for disposal of treated affluent worldwide are mentioned
below and described in subsequent section.
� Natural Evaporation
� Urban Reuse
� Industrial Reuse
� Agriculture Reuse
� Recreational Reuse
� Ground water recharge
� Discharge into natural waters
� Flushing of sewers
9.6.1 Natural Evaporation
Natural evaporation involves large impoundments with no discharge. The evaporation process
depends on temperature, wind velocity and humidity. Considering the climatic conditions of
Raipur and premium of Land, this method is not adoptable.
9.6.2 Urban Reuse
Urban reuse implies use of effluent for non-potable purposes like application to public parks,
golf courses, highways medians, landscape areas etc. The important parameter to note before
reuse is the assurance and reliability of treated effluent with respect to contamination of public
health. There is a potential of about 3 to 5% reuse of treated effluent, which may be gradually
increased depending upon requirement and adopting stringent effluent criteria.
9.6.3 Industrial Reuse
Worldwide municipal effluents (BOD<5 mg/l, SS=15 mg/l) are having great demands for
industrial applications, particularly for makeup water in industrial cooling. However, there are
inherent problem due to stringent water quality requirement for industries depending upon
process. In Raipur, the reuse in industrial sector is limited. But the demand for industrial reuse in
Raipur is not known.
9.6.4 Agriculture Reuse
The environmental protection act of 1986 has promulgated standards for effluent in respect of
irrigation. The BOD level of 100 mg/l and SS level of 200 mg/l is permitted for land irrigation.
Since the fringe areas in the valley of proposed STP locations have agricultural load, this aspect
presents a favourable option for reuse of effluent for agricultural purpose. Many studies have
been conducted by scholars and research institutes to study the suitability of effluent use for
agriculture with emphasis on cash crops, fodder and cereal crops. The potential of this
application shall be studied in detail during DPR stage.
9.6.5 Recreational Reuse
Many municipalities offer treated effluent for recreational reuse like fish ponds, lakes for
boating, ornamental fountains etc. but the standards are as near as potable water. The extent of
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reuse and potential of human contact defines the treatment standards in such case. RMC may
study this aspect independently in years to follow, about recreational reuse.
9.6.6 Ground Water Recharge
Two methods of ground water recharge are widely adopted, (i) surface spreading and (ii) direct
injection. There is potential of ground water recharge since all over the country GW table is
declining. RMC at later stage may involve CGWB authorities to explore possibility of ground
water recharge using treated effluent.
9.6.7 Discharge into Natural Waters
This is one of the most commonly and widely adopted methods of treated effluent disposal.
Normally STPs are located in the vicinity of natural water bodies so that effluent can be
discharged into them. The EPA (1986) has set standards for disposal of effluent into inland water
bodies. The BOD level of 30mg/l and SS Level of 100mg/l is permitted. This method seems to be
most appropriate for this project since Kharun river and its tributaries are available nearby the
proposed STP to act as receiving bodies for effluent. However, the EIA study is expected to study
and present the impact of this method.
9.6.8 Flushing of Sewers
Recently many municipalities have started using the treated effluent for flushing periodically
their sewer system. Though limited and intermittent application are involved in flushing the
sewers where low velocities prevail. It would be appropriate at this stage to study and present
the applicability of reuse of effluent to flush the sewer system.
9.7 Conclusion
With reference to the discussion in section 3.16, in summary, natural evaporation requires large
land and is affected by climatic conditions and may cause ground water contamination.
Exceptionally high quality effluent is needed for urban reuse, industrial reuse, ground water
recharge and recreational reuse. Potential for agricultural reuse exist, which requires positive
information dissemination to users. The effluent quality expected out of ASP is sufficient to
permit its safe disposal into nearby receiving waters while meeting the statutory requirement of
the state. Therefore, effluent disposal into natural waters has been selected.
***
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Environmental Impacts 10101010
10.0 Environmental Impacts
10.1 Objectives of Environmental Impacts
An Environmental Impact Assessment (EIA) is “a structured approach for obtaining and
evaluating environmental information prior to its use in decision-making in the development
process. This information includes predictions on how the environment is expected to change if
certain alternative actions are implemented and advice on how best to manage environmental
changes if one alternative is selected and implemented”. The EIA report is required for seeking
No Objection Certificate from Chhattisgarh State Environmental Conservation Board.
10.2 EIA Process
The first step of EIA process is to determine whether a project falls within the relevant act or
regulations, and whether the development is likely to create significant environmental
disruption. If so, an assessment is undertaken, for the preparation of an Environmental Impact
Assessment / Environmental Management Plan report consisting of existing / proposed
activities, critical areas, probable impacts, recommended mitigation measures, post project
monitoring programme, details of environmental management cell etc. The project is assigned
category B / B1 environmental category as per the new MoEF notification dated 14-09-2006.
10.2.1 Approach & Methodology for EIA
The technical approach adopted during EIA study is presented in Figure below. The study was
conducted in two phases;
� Phase –I: Desk Study and Scoping
� Phase –II: EIA study
The methodology for conducting the Phase-I studies is given below.
10.2.2 Desk Study and Scoping
Desk study was conducted to collect and review the environmental regulations, legislation,
policy guidelines and control that may impact this project and the data related to; (i)
physiography and land-use, (ii) environmental pollution and health, (iii) ecology, (iv) agriculture,
and (v)infrastructure. The “scoping of environmental issues” has a brief description of the
scheme and the existing environment, potential environmental effects (in form of checklist)
arising from the construction and operation of the project. Potential environmental effects are
identified under four main headings: water and ecology, land and resources, pollutants and their
effects and human activities.
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Approach For EIA Study
Desk Research, Reconnaissance,
Refer GoI Guidelines
Scoping / Identification of
Parameters
Environmental Baseline Data Generation Field Studies
Potential Env. & Social
Impact Assessment
Preparation of Environmental
Mitigation / Management Plan,
Rehabilitation Action Plan
Environmental Monitoring Programs /
Monitoring of RAP
Via
bil
ity o
f
Ma
na
ge
me
nt
No impact
Ecology
� Flora
� Fauna
� Tree
survey � Fisheries
Environmental Pollution
� Air
� Water
� Noise
� Soil
� Solid waste
Physical / Land
� Topography
� Land use pattern
� Geology
� Drainage/ hydrology
� Archaeology
Socio-Economics
� Social Status
� Occupation
� Infrastructure
facilities
� Cultural status
Screening of Environmental / Social
Analysis of Environmental /
Social Baseline Data
PH
AS
E –
I: S
CO
PIN
G &
DE
SK
ST
UD
Y
PH
AS
E –
II (
EIA
+ S
A)
Field visit
Public Consultation
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Physiography and Land-use covers data on topography, soils, erosion, geology, seismicity and
minerals. Water Resources cover data on rivers, floods, ground water and water quality. Data on
Environmental status cover air, noise, water and soil pollution levels in ambient environment.
The existing water supply and sanitation conditions, public health, type of diseases prevalent in
project area are compiled. Ecology covers data on flora, fauna, trees, species of flora and fauna,
terrestrial and aquatic life, in the project area. Agriculture cover data on culturable land, type of
crops, practices of irrigation, yield of crops, agriculture techniques and infrastructure for
irrigation. The data on archaeology comprise sites of archaeological and cultural importance,
monuments and sites of religious importance. Data was compiled by field investigations and
discussions with various departments and details from statistical handbook of Raipur and
published literature on project area. The study is carried in the influence area of RMC limits.
10.3 Impact Assessment
The identification of negative and positive impacts for the project has been carried out by using
matrix (refer Table 10.1). The matrix includes all possible negative and positive impacts
associated with construction of sewerage lines, construction and operation of pumping stations
and STPs. The evaluated environmental impacts of this project along with mitigation measures
and management plans are submitted separately in Volume- IX.
Table-10.1: Preliminary EIA Matrix
SOCIAL ENVIRONMENT NATURAL POLLUTION Environmental Parameter
Development Scheme Re
sett
lem
en
t
Eco
no
mic
Act
ivit
y
Tra
ffic
Pu
bli
c U
tili
tie
s
Cu
ltu
ral
Pro
pe
rtie
s
Pu
bli
c H
ea
lth
So
lid
Wa
ste
To
po
gra
ph
y a
nd
Ge
olo
gy
So
il E
rosi
on
Gro
un
d W
ate
r
Flo
ra a
nd
Fa
un
a
Lan
dsc
ap
e
Air
Po
llu
tio
n
Wa
ter
Po
llu
tio
n
So
il C
on
tam
ina
tio
n
No
ise
Od
or
C
A
+
B
A
+
B
B B B * * B * * * * * * * * Installation of Sewers
O * * * * * B * * * * * * * * * * *
C B * B * * * * * * * * * * * * B * Sewage Pumping
Station O * * * * * B B * * * * * * * * B *
C
A
+
B
A
+
B
B * * * B * * * B
A
+
B * *
A
+
B
B *
O * * * * * B B * * B * * *
A
+
B
A
+
B
B
A
+
B
Sewage Treatment
Plant
O * * B B B B
A
+
B * * B * * * B * * *
A: Indicates that the project component is foreseen to have some impact on the environmental parameter
B: Indicates that the impact is not quite sure and examination is required
* : Indicates no impact on the environmental parameter.
C: Construction O: Operation
***
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Operation and Maintenance 11111111
11.0 Operation and Maintenance
As sewer system networks age, the risk of deterioration, blockages, and collapses becomes a
major concern. As a result, municipalities worldwide are taking proactive measures to improve
performance levels of their sewer systems. Cleaning and inspecting sewer lines are essential to
maintaining a properly functioning system; these activities further a community's reinvestment
into its wastewater infrastructure. It is also accepted that, for quality maintenance of sewerage
system, optimum use of labour, equipment and material is required to keep the system in good
condition so that sewage is efficiently conveyed up to the treatment site.
11.1 Necessity of Maintenance
Once laid, “a sewer system is away from site away from mind” this results in facing a problem
that occurs either due to a blockage or a settlement causing inconvenience to the residents as
well as to the traffic. This calls for not only a remedial action but a planned view for periodical
maintenance of the sewer system, both preventive as well as proactive. Maintenance helps to
protect the capital investment and ensures an effective and economical expenditure in
operating and maintaining the sewerage facilities.
Sewer maintenance functions are too often neglected and given attention only as emergency
arises. Adequate budgets are seldom provided for supervision, manpower and equipment,
unlike the case for maintenance of other utilities like electric cables, telephone cables, gas and
water mains. Such attitude towards sewer maintenance is found even in large cities. Considering
the health hazards that the public at large has to face, it will be appropriate to provide sufficient
funds to take care of men, material, equipment and machinery required for efficient
maintenance of the proposed sewerage infrastructure.
All efforts should be made to see that there is no failure in the internal drainage system of a
premise. A serious health hazard results when sewage backs up through the plumbing fixtures or
into the basements. The householder is confronted with the unpleasant task of cleaning the
premises after the sewer line has been cleaned. Extensive property damage may also occur,
particularly where expensive appliances are located in the basements.
Maintenance helps to protect the capital investment and ensures an effective and economical
expenditure in operating and maintaining the sewerage facilities. It also helps to build up and
maintain cordial relations with the public, whose understanding and support are essential for
the success of the facility.
11.2 O&M for the project
During the DPR presentation, following aspects on O&M of sewerage system, SPS and STP shall
be presented in the form of manual of practice.
� Organization for O&M
� Planning for O&M
• Preventive maintenance
• Emergency maintenance
� Tools for O&M
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� Hazards related to O&M
� Precautions during O&M
• Safety of personnel
• Traffic control
• Safety equipment
� Methods of sewer rehabilitation
� Training of personnel
� Record keeping
The operation and maintenance of proposed sewerage system, including repairs and renovation
of sewers and revenue collection shall rest with RMC. Knowing that the O&M of STPs and
pumping stations is a specialized job requiring skilled manpower, which at this juncture is not
available with RMC. Condition of operation and maintenance of the STPs for a period of 3 years
by the agency responsible for construction and commissioning of the STP, after the completion
of defect liability period of 3 months from the date of satisfactory completion / commissioning,
will be incorporated in the Tender Conditions . Similar condition is proposed to be incorporated
for SPSs.
The construction agency will also be called upon to provide a Manual of Operation and
Maintenance as also propose optimal staff and Tools & Plants (T&P) for the smooth operation of
the created facilities. This would not only provide RMC with a trouble free operation of the
newly created assets but will also provide RMC, an opportunity to train the in-house eligible staff
on the job for acquiring O&M skills. Over the years RMC will require to set up a maintenance
division for the sewer system well equipped with men, material and T&P so as to render efficient
service in an emergency like situation as also carry out preventive periodical maintenance.
11.3 Road Restoration
The construction of sewer network requires excavation of trenches, which in turn would lead to
removal of road surfaces. However, the road surfaces disturbed due to installation of pipes are
restored to its original standards after refilling of excavated trenches. It is observed in many
instances, that the restoration works are executed with substandard approach, thus leading to
erosion of the soils. Subsequently the effect of wear and tear along with weathering culminates
to form a pot hole and ultimately affect the riding comfort. Sometimes this condition of road
surface becomes a cause of road accidents.
Under this project about 1032 km of sewerage network is to be laid in the municipal area, where
sewer pipes from 150 mm to 2200 mm are to be installed. These roads are of commercial
importance and carry city traffic. Hence it is very pertinent to consider the restoration of these
roads up on installation of sewer lines. Typically the road to be restored would be varying from 3
m to 24 m in width. In the cost computations the roads under complete network are considered
for restoration.
The specifications for restoration works are based on the MoRTH standards. The cost of
restoration works is taken along with cost of sewerage network, the details of which are
available in Volume-IV: Cost Estimates.
***
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Project Management 11112222
12.0 Project Management
Once the project design phase is completed, the project team, usually the Project Manager and
the analysts in the early stages, determines scope of efforts necessary to accomplish tasks of
construction. Various methods are adopted for accomplishing this planning process; e.g. use of
graphics, charts. Since this project is a time bound project and to be finished within 28 months,
hence to ensure successful and timely completion of project, a technically sound project
management is required.
12.1 Construction
Construction of sewers and its appurtenances, sewage pumping stations and sewage treatment
plant shall be carried out using mechanized construction tools and equipments to achieve
maximum output. Use of prefabricated material is encouraged to improve quality of works,
simultaneously improving efficiency of construction schedule. Contract documents for the
project are framed such that, it would be compulsory for the prospective bidders / contractors
to present a detail write-up and oral presentation on the following aspects of construction.
• Methodology of Construction (Method Statement),
• Site Management,
• Construction Schedule,
• Environment & Traffic Management,
• Cash Flow Projections,
• Schedule of Deployment of Machinery & Equipments,
• Schedule of Labour Deployment,
• Deployment of Technical Staff with Qualification & Experience,
• Quality Assurance Programme,
• Time & Cost Saving devices, if any.
A sample list machinery and equipment is given in Table 12.1. However certain important
elements of construction are presented in subsequent sections.
Table-7.1: List of Construction Equipment
Equipment Trench
Excavation
Construction/
Laying of pipe
Back fill Other
Concrete Batching Plant Y
Concrete Mixing Machine Y
Mobile Crane Y
Dump Truck Y Y Y
Water truck Y
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Table-7.1: List of Construction Equipment
Equipment Trench
Excavation
Construction/
Laying of pipe
Back fill Other
Bulldozer/ Excavators Y Y
Piling Equipment with vibro-hammer Y
BACKHOE for laying sewer Y
Excavators (power shovels bucket
type)
Y
Hydraulic Winch Y
Fork Lifters Y
Mobile diesel Generators Y
Portable Pneumatic/ Electric
i)Concrete Pavement Cutter/hammer
ii)Spare Discs
Y
Portable Pneumatic/ Electric
i) Pipe Cutters
ii) Spare Discs
Y
Power driven Dewatering Pump-sets Y
TS Equipment including GPS Y
12.1.1 Excavation
Trenches shall be excavated to the specified depth below the barrel of pipe. The excavation of
trenches for pipelines shall be done mechanically using appropriate equipments. The guidelines
for excavation of trenches as mentioned in PHE-USR shall also be referred appropriately. The
proposed excavation at any one time shall be limited to such lengths, which does not cause
inconvenience to surrounding inhabitants and road traffic.
12.1.2 Installation of Sewer Pipes
Installation of sewer pipes includes the supply, laying and jointing of pipes and fittings,
construction of beddings and foundations, manholes and other structures in the line, testing,
back filling of trenches, surface restoration, disinfection and commissioning. Installation of
pipelines shall in-principle follow the recommendations of IS: 783-1985 "Code of Practice for
laying of concrete pipes".
12.1.3 Bedding
Granular bedding for pipes shall be placed by spreading and compacting granular bedding
material over the complete width of the pipe trench. Where pipes are jointed, bell holes of
ample dimensions shall be formed in the bedding to ensure that each pipe is uniformly
supported throughout the length of its barrel and to enable the joint to be made and inspected
during testing. After pipe laying additional material shall be placed and compacted by hand
rammer in 150 mm layers equally on each side of the pipe. Pipes shall be laid on setting blocks
only where a concrete bed or cradle is used.
12.1.4 Handling of Pipes
While loading, unloading, or otherwise handling, the greatest care shall be taken to avoid shocks
likely to cause cracking, chipping or any other damage to pipes or fittings or to their coatings. All
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pipes and fittings too heavy to be carried by hand shall be loaded and off-loaded only by means
of a crane or any other approved lifting and handling device, with slings or hooks suitably
padded. In this case recesses shall be dug beneath the invert to permit the slings or ropes to be
properly withdrawn. Particular care shall be taken to ensure that sheeting and lining are intact
before jointing pipes and fittings. No pipes shall be rolled into place for lowering. Before any
piping is lowered into the trench, it shall be cleaned and examined for cracks, flaws etc. whilst
hanging in the sling, and to see that no earth or foreign matter is within the pipe barrel or
coupling. No protective cap, or disc or other appliance shall be removed permanently until the
pipe or fitting that it protects is about to be jointed.
12.1.5 Jointing and Cutting
All joints shall be flexible mechanical joints and comply with the relevant provisions of the
appropriate Indian Standard and shall be made to the manufacturer's recommendations and the
Specifications. Rubber rings for S&S sewer pipes shall be complying with the relevant provisions
of Indian Standard and shall be obtained from the pipe manufacturer. Collar joints shall be of
cement and sand mortar with 1:2 proportions. Collar joints shall be provided only when rubber
ring joints cannot be provided. The joint shall be bevelled off at 45° from the outside edge of the
collar. Pipes shall be cut by a method which provides a clean square profile without splitting or
fracturing the pipe wall, and which causes minimum damage to any protective coating. Where
necessary, the cut ends of pipes shall be formed to the tapers and chamfers suitable for the type
of joint to be used and any protective coatings shall be made good.
For ductile pipes to be cut to form non-standard lengths, the manufacturer's recommendations
in respect of ovality correction to the cut spigot end shall be followed.
12.1.6 Placing and Compaction of Fill and Backfill
Handling, placing, spreading, compacting, wetting, trimming and quality control of fill material
for compacted fill shall be as shown on the drawings or in accordance with the specifications. Fill
shall be spread by manual / machine in successive horizontal layers of not more than 150 mm
loose depth. Longitudinal or transverse joints in any two successive layers shall be staggered by a
minimum distance of 3 m.
Samples of all materials for testing, both before and after placement and compaction, shall be
taken at frequent intervals. From these tests, corrections, adjustments, modifications of
methods, materials and moisture content shall be made. Compaction operations shall be
continued until the embankment is compacted to not less than 95% of the standard maximum
dry density, at optimum moisture content as determined by the compaction control tests as per
relevant code of practice. Compaction of fill shall be done by using approved compacting
equipments like pneumatic rubber tyred rollers, tamping rollers and other approved compacting
equipment.
Where excavations have been supported and the supports are to be removed, these, where
practicable, shall be withdrawn progressively as backfilling proceeds in such a matter as to
minimize the danger of collapse, and all voids formed behind the supports shall be carefully
filled and compacted. Only if this is not possible the supports shall be cut off and left in the
ground.
12.1.7 Disposal of Surplus Material
The surplus excavated material shall be disposed off at locations proposed on drawings, in an
environmentally friendly manner. Storing excavated material, whether temporarily or
permanently, shall be subject to prior approval. Where required, drains shall be constructed to
prevent the undesirable accumulation of water in or around spoil dumps.
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12.2 Prefab Reinforced Concrete Manholes
Prefabricated reinforced concrete manholes are very commonly used in European countries and
also in south-east Asian countries. These manholes offer good strength as compared to
conventional brick manholes and fast assembling. Considering the limited time frame of this
project, use of prefabricated manholes suits best to achieve the overall objective of structurally
sound and hydraulically safe system. These manholes are successfully implemented in the under
construction “Bilaspur Sanitary Sewerage Scheme” in Chhattisgarh State.
The prefab RCC manhole shall have four components, (i) precast monolithic base section, (ii)
modular riser section, (iii) top cone section and (iv) adjusting rings.
� Manholes prefabricated from reinforced concrete shall be manufactured at work
sites in accordance with the specifications and drawings.
� Manhole diameters shall range from 0.91 m to 1.52 m at the base.
� Concrete used in the construction of the manholes shall be of grade M-30 using
sulphate resistant cement.
� The wall thickness shall be a minimum of 150 mm or as per design.
� Manhole units shall consist of standard modular pre-cast riser sections, modular
cone sections, and a monolithic base.
� Manhole modules shall be provided coatings on the interior of the manhole such
as coal-tar epoxy to negate the effect of H2S concentration.
The “O” ring joint shall conform to the requirements of ASTM C443, Standard Specification for
Joints for Circular Concrete Sewer and Culvert Pipe, Using Rubber Gaskets or latest revision. The
gasket joint shall conform to ASTM C990, Standard Specification for Joints for Concrete Pipe,
Manholes, and Precast Box Sections Using Preformed Flexible Joint Sealants (or AASHTO M-199)
or latest revision. Rubber boot and stainless steel clamps, meeting the requirements of ASTM
C923, Standard Specification for Resilient Connectors between Reinforced Concrete Manhole
Structures, Pipes and Laterals shall be supplied with the manhole bases to tie the pipe to the
base section of the manhole.
Placement of Manhole Sections: Pre-cast manhole sections shall be placed and aligned to
provide vertical sides. The completed manhole shall be rigid, true to dimensions, and watertight.
The joints between manhole sections shall be properly sealed utilizing an approved rubber
gasket and butyl rubber rope.
Placement of Adjusting Rings: Where one (1) solid riser or barrel section cannot be used, final
adjustments in elevation of the casting frame and cover shall be accomplished by the use of pre-
cast concrete adjusting rings of a minimum thickness of 100 mm. The total number of adjusting
rings shall be varying in depth from 100 mm to 300 mm. The use of brick or block in lieu of
adjustment rings is not allowed.
Connections to Manholes: Sanitary sewer connections to existing manholes shall be core-drilled
and made using a flexible rubber connector. Saw cutting and hammer taps are prohibited. All
connections shall provide for a watertight seal between the pipe and the manhole. The
connector shall be the sole element relied upon to assure a flexible water tight seal of the pipe
to the manhole.
12.3 Important Aspects During Construction
Following are some of the important aspects during construction, for which specifications are
also included in the contract documents.
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NOTICES: The Contractor shall, before commencement of the work, shall display, and correctly
maintain, in a clean and legible condition at a conspicuous place on the Site, notices in English
and in a language spoken by the majority of the workers, stating therein the rate of wages which
have been fixed as fair wages and the hours of work for which such wages are earned and send a
copy of such notices to the Chief Resident Engineer of Project Management Consultant.
The Contractor shall pay the labourers engaged by him on the work not less than fair wage
which expression shall mean, whether for time or piecework, the respective rates of wages fixed
by the Public Works Department as fair wages for the area payable to the different categories of
labourers or those notified under the Minimum Wages Act for corresponding employees of the
Employer, whichever may be higher.
Safety Provisions:
The Contractor shall comply with all the precautions as required for the safety of the workmen
by the ILO Convention No.167 (Safety & Health in Construction) as far as they are applicable to
the contract. The Contractor shall provide all necessary safety appliances, gears like goggles,
helmets, masks, etc., to the workmen and the staff.
(i) Suitable scaffolds shall be provided for workmen for all work that cannot safely be done
from the ground, or from solid construction except for such short period work as can be
done safely from ladders, When a ladder is used, an extra labour shall be engaged for
holding the ladder and if the ladder is used for carrying materials as well, suitable foot-holds
and hand-holds shall be provided on the ladder.
(ii) Scaffolding or staging more than 3.25 m above the ground or floor, swing or suspended
from an overhead support or erected with stationary support shall have guard rail properly
attached bolted, braced and otherwise secured 1 m high above the floor or platform of such
scaffolding or staging and extending along the entire length may be necessary for the
delivery of materials. Such scaffolding or staging shall be so fastened as to prevent it from
swaying from the support for structure.
(iii) Working platform, gangways, and stairways shall be so constructed that they do not sag
unduly or unequally and if a height of a platform or gangway or stairway is more 3.25 m
above ground level or floor level, it shall have closely spaced boards, have adequate width
and be suitably provided with guard rails as described in (ii) above.
(iv) Every opening in floor of a structure or in a working platform shall be provided with suitable
means to prevent fall of persons or materials by providing suitable fencing or railing with a
minimum height of one m.
(v) Safe means of access shall be provided to all working platforms and other working places.
Every ladder shall be securely fixed. No portable single ladder shall be over 9 m in length.
Width between side rails in a rung ladder shall in no case be less than 30 cm for ladders upto
and including 3 m in length. For longer ladders the width shall be increased at least 6mm for
each additional 30cm of length. Spacing of steps shall be uniform and shall not exceed 30cm.
Adequate precautions shall be taken to prevent danger from electrical equipment. No materials
on any of the sites shall be so stacked or placed as to cause danger or inconvenience to any
person or the public. The Contractor shall provide all necessary fencing and lights to protect
public from accidents and shall be bound to bear expenses of defending every suit, action or
other proceedings at law that may be brought by any person for injury sustained owing to
neglect of the above precautions and to pay any damages and cost which may be awarded in
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any such suit, action or proceeding to any such person or which may with the consent of the
Contractor be paid to compromise any claim by any such person.
Excavation and Trenching: All trenches, 1.5 m or more in depth shall at all times be supplied with
at least one ladder for each 20 metres in length or fraction thereof. Ladder shall be extended
from bottom of trench to at least 1 m above surface of the ground. Sides of trench which is 1.5
m or more in depth shall be stepped back to give suitable slope or securely held by timber
bracing, so as to avoid the danger of collapsing of sides. Excavated material shall not be placed
within 1.5 m of edge of trench or half the depth of trench, whichever is more. Cutting shall be
done from top to bottom. Under no circumstances, undermining or undercutting shall be done.
Demolition: Before any demolition work is commenced and also during the process of the work:
a. All roads and open areas adjacent to the work site shall either be closed or suitably
protected.
b. No electric cable or apparatus which is liable to be a source of danger over a cable or
apparatus used by operator shall remain electrically charged.
c. All practical steps shall be taken to prevent danger to persons employed by the Employer,
from risk of fire or explosion, or flooding.
General Safety Measures: All necessary personal safety equipment as considered adequate by
the Project Management Consultant shall be available for use of persons employed on the Site
and maintained in a condition suitable for immediate use and the Contractor shall take adequate
steps to ensure proper use of the equipment by those concerned.
i. Workers employed on mixing asphaltic materials, cement, lime mortars/concrete shall be
provided with protective footwear and protective goggles.
ii. Those engaged in handling any material which is injurious to eyes shall be provided with
protective goggles.
iii. Those engaged in welding works shall be provided with welder's protective eye-shield.
iv. Stone breakers shall be provided with protective goggles and protective clothing and seated
at sufficiently safe intervals.
v. When workers are employed in sewers and manholes, which is in use, the Contractor shall
ensure that manhole covers are open and manholes are ventilated at least for an hour
before workers are allowed to get into them. Manholes so open shall be cordoned off with
suitable railing and provide warning signals or boards to prevent accident to public.
The Contractor shall not employ men and women labourers below the age of 18 years. The
Contractor shall not employ women on the work of painting with products containing lead in any
form. Whenever men above the age of 18 years are employed on the work of lead painting, the
following precautions shall be taken.
• No paint containing lead or lead products shall be used except in the form of paste or ready
made paint.
• Suitable face masks shall be supplied for use by workers when paint is applied in the form of
spray or a surface having lead paint dry rubbed and scrapped.
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• Overalls shall be supplied by the Contractor to workmen and adequate facilities shall be
provided to enable workers to wash during and on close of day's work.
When work is done near any place where there is risk of drowning, all necessary equipment shall
be provided and kept ready for use and all necessary steps taken for prompt rescue of any
person in danger and adequate provision made for prompt first aid treatment of all injuries likely
to be sustained during the course of the work.
Use of hoisting machines and tackle including their attachments, anchorage and supports shall
conform to the following:
(A) (i) These shall be of good mechanical construction, sound material and adequate
strength and free from patent defects and shall be kept in good adequate strength and
free from patent defects and shall be kept in good working order and properly
maintained.
(ii) Every rope used in hoisting or lowering materials or as a means of suspension shall be
of durable quality and adequate strength, and free from defects.
(B) Every crane driver or hoisting appliance operator shall be properly qualified and no person
under the age of 21 shall be in charge of any hoisting machine including scaffold or of signals
to operator.
(C) In case of every hoisting machine and of every chain hook, shackle swivel and pulley block
used in hoisting, lowering or as means of suspension, safe working load shall be ascertained
by adequate means. Every hoisting machine and all gear referred to above shall be plainly
marked with safe working load. In case of a hoisting machine or a variable safe working load
each safe working load and conditions under which it is applicable shall be clearly indicated.
No part of any machine or any gear referred to above in the paragraph shall be loaded
beyond safe working load except for the purpose of testing.
(D) In case of the Employer's machine, safe working load shall be notified by the Engineer or his
representative. As regards Contractor's machines, the Contractor shall notify safe working
load of each machine to Engineer or his representative whenever he brings it to site of work
and get it verified by him.
Motors, gearing, transmission, electric wiring and other dangerous parts of hoisting appliance
shall be provided with efficient safeguards hoisting appliances shall be provided with such
means as will reduce the risk of accident during descent of load to the minimum. Adequate
precautions shall be taken to reduce to the minimum risk of any part of a suspended load
becoming accidentally displaced. When workers are employed on electrical installations which
are already energised, insulating mats, working apparel such as gloves, sleeves and boots, as
may be necessary, shall be provided, workers shall not wear any rings, watches and carry keys or
other material which are good conductors of electricity.
All scaffolds, ladders and other safety devices mentioned or described herein shall be
maintained in safe condition and no scaffold, ladder or equipment shall be altered or removed
while it is in use. Adequate washing facilities shall be provided at or near places of work.
These safety provisions shall be brought to the notice of all concerned by display on a notice
board at a prominent place at the workspot. Persons responsible for ensuring compliance with
the safety code shall be named therein by the Contractor.
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To ensure effective enforcement of the rules and regulations relating to safety precautions,
arrangements made by the Contractor shall be open to inspection by the Engineer or his
representative and the Inspecting Officer as defined in the Contractor's Labour Regulation
mentioned in thereafter these Documents as Annexure A of Section IV.
Notwithstanding anything contained in conditions above, the Contractor shall remain liable to
comply with the provisions of all Acts, rules, regulations and byelaws for the time being in force
in India and applicable in this matter.
Footwear: The contractor shall at his own expense provide footwear for all labour engaged on
concrete mixing work and other types of work involving the use of tar, cement, etc., to the
satisfaction of the Engineer or his Representative, and on his failure to do so, the Employer shall
be entitled to provide the same and recover the cost from the Contractor.Local Labour: The
Contractor is encouraged as far as possible to employ, in the execution of the Contract, qualified
Indian citizens as workmen. Employment of expatriate personnel is subject to the Indian Laws
and Regulations. In case the contractor wishes to employ expatriate personnel in any particular
trade or skill required to execute the contract, the Employer will assist the Contractor in
obtaining permission for which the Contractor shall submit requisite data.
Model Rules for Labour Welfare
(i) Definitions
o Workplace means a place at which, on an average, twenty or more workers are employed.
o Large workplace means a site at which, on an average, 250 or more workers are employed.
(ii) First Aid
At every workplace, there shall be maintained in readily accessible place first aid appliances
including an adequate supply of sterilized dressings and sterilized cotton wool as prescribed
in the Factory Rules of the State in which the work is carried on. The appliances shall be kept
in good order and, in large workplaces; they shall be placed under the charge of a
responsible person who shall be readily available during working hours.
At large workplaces, where hospital facilities are not available within easy distance of the Works,
First Aid Posts shall be established and be run by a trained compounder.
Where large workplaces are remotely situated and far away from regular hospitals, an indoor
ward shall be provided with one bed for every 250 employees.
Where large workplace are situated in cities, towns or in their suburbs and no beds are
considered necessary owing to proximity of city or town hospitals, suitable transport shall be
provided to facilitate removal of urgent cases to these hospitals. At other workplaces, some
conveyance facilities shall be kept readily available to take injured person on persons suddenly
taken seriously ill, to the nearest hospital.
At large workplaces, there shall be provided and maintained an ambulance room containing the
prescribed equipment and in the charge of such medical and nursing staff as may be prescribed.
For this purpose, the relevant provisions of the Factory Rules of the State government of the area
where the work is carried on, may be taken as the prescribed standard.
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(iii) Accommodation for Labour:
The Contractor shall during the progress of the Work provide, erect and maintain necessary
temporary living accommodation and ancillary for labour at his own expenses to the standards
and scales as approved by the Engineer.
(iv) Drinking Water
In every workplace, there shall be provided and maintained at suitable places, easily accessible to
labour, a sufficient supply of cold water fit for drinking. Where drinking water is obtained from
an intermittent public water supply, each workplace shall be provided with storage of cold water
fit for drinking.
Water supply storage shall be at a distance of not less than 15 m from any latrine, drain or other
source of pollution. Where water has to be drawn from an existing well, which is within such
proximity of latrine, drain or any other source of pollution, well shall be properly chlorinated
before water is drawn from it for drinking. All such wells shall be entirely closed in and be
provided with a trap door which shall be dust-proof and water-proof. A reliable pump shall be
fitted to each covered well. The trap door shall be kept locked and opened only for cleaning or
inspection which shall be done at least once a month.
(v) Washing and Bathing Places
Adequate washing and bathing places shall be provided separately for men and women. Such
places shall be kept in clean and drained condition.
(vi) Scale of Accommodation in Latrines and Urinals
There shall be provided within the precincts of every workplace, latrines and urinals in an
accessible place, and the accommodation, separately for each of these, shall not be less than at
the following scale:-
Description No. of Seats
(a) Where number of persons does not exceed 50 2
(b) Where number persons exceed 50 but does not exceed
100
3
(c) For additional persons per 100 or part thereof 3
In particular cases, the Engineer shall have the power to increase the requirement, wherever
necessary.
(vii) Latrines and Urinals
Except in workplaces provided with water/flushed latrines connected with a water borne sewage
system, all latrines shall be provided with receptacles on dry-earth system which shall be cleaned
at least four times daily and at least twice during working hours and kept in a strictly sanitary
condition. Receptacles shall be tarred inside and outside at least once a year.
If women are employed, separate latrine and urinals, screened from those for men and marked in
the vernacular in conspicuous letters. "For Women Only" shall be provided on the scale laid down
in rule (vi). Those for men shall be similarly marked "For Men Only". A poster showing the figures
of a man and a woman shall also be exhibited at the entrance to latrines for each sex. There shall
be adequate supply of water, close to latrines and urinals.
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(viii) Construction of Latrines
Inside walls shall be constructed of masonry or other non-absorbent material and shall be
cement washed inside and outside at least once a year. The dates of cement washing shall be
noted in a register maintained for the purpose and kept available for inspection. Latrines shall
have at least thatched roof.
(ix) Disposal of Excreta
Unless otherwise arranged for by the local sanitary authority, arrangement for proper disposal of
excreta by incineration at the workplace shall be made by means of suitable incinerator approved
by the local medical, health and municipal or cantonment authorities. Alternatively, excreta may
be disposed off by putting a layer or night soils at the bottom of a pucca tank prepared for that
purpose and covering it with a 15 cm layer of waste or refuse and then covering it with a layer of
earth for a fortnight (when it will turn into manure).
The Contractor shall, at his own expense, carry out all instructions issued to him by the Engineer
to effect proper disposal of soil and other conservancy work in respect of Contractor's work-
purpose or employees on the site. The Contractor shall be responsible for payment of any charges
which may be levied by municipal or cantonment authority for execution of such work on his
behalf.
(x) Provisions of shelters during rest
At every workplace, there shall be provided, free of cost, four suitable sheds, two for meals and
two others for rest, separately for use of men and women labour. Height of each shelter shall not
be less than 3 m from floor-level to lowest part of roof. Sheds shall be kept clean and the space
provided shall be on the basis of at least 0.5 m2 per head.
(xi) Crèches
At a place at which 20 or more women are ordinarily employed, there shall be provided at least
one hut for use of children under the age of 6 years belonging to such women. Huts shall not be
constructed to a standard lower than that of thatched roof, mud floor and wall with wooden
planks spread over mud floor and covered with matting.
Huts shall be provided with suitable and sufficient openings, for light and ventilation. There shall
be adequate provision of sweepers to keep the places clean. There shall be two maid-servants in
attendance. Sanitary utensils shall be provided to the satisfaction of local medical, health and
municipal or cantonment authorities. Use of huts shall be restricted to children, their attendants
and mothers of children.
Where the number of women workers is more than 25 but less than 50, the Contractor shall
provide at least one hut and one maid-servant to look after children of women workers. Size of
crèches(s) shall vary according to the number of women workers employed.
Crèches(s) shall be properly maintained and necessary equipment like toys, etc., provided.
(xii) Canteen
A cooked food canteen on a moderate scale shall be provided for the benefit of workers wherever
it is considered necessary.
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(xiii) Planning, setting and erection of the above mentioned structures shall be approved by
the Engineer or his representative and the whole of such temporary accommodation shall at all
times during the progress of the work be kept tidy and in a clean and sanitary condition to the
satisfaction of the Engineer or his representative and at the Contractor's expense. The Contractor
shall conform generally to sanitary requirements of local medical, health and municipal or
cantonment authorities and at all times adopt such precautions as may be necessary to prevent
soil pollution of the site.
On completion of the Works, the whole of such temporary structures shall be cleared away, all
rubbish burnt, excreta or other disposal pits or trenches filled in and effectively sealed off and the
whole of site left clean and tidy at the contractor's expense to the entire satisfaction of the
Engineer.
(xiv) Anti-malarial precautions
The Contractor shall, at his own expense, conform to all anti-malarial instructions given to him by
the Engineer, including filling up any borrow pits which may have been dug by him.
(xv) Enforcement
Inspecting Officer mentioned in the Contractor's Labour Regulations or any other Officer
nominated on his behalf by the Engineer shall report to the Engineer all cases of failure on the
part of the Contractor and/or his sub-contractor to comply with the provisions of these Rules
either wholly or in part and the Engineer shall impose such fines and other penalties as are
prescribed in the conditions of contract.
(xvi) Interpretations, etc.
On any question as to the application, interpretation or effect of these Rules, the decision of the
Chief Labour Commissioner or Deputy Chief Labour Commissioner (Central) shall be final and
binding.
(xvii) Amendments
The Employer may, from time to time, add to, or amend these Rules and issue such directions as
it may be considered necessary for the proper implementation of these Rules or for the purpose
of removing any difficulty which may arise in the administration thereof.
Relocation of Utilities: It shall be the responsibility of the Contractor to liaise, coordinate, follow
up and obtain all information available from the relevant Authorities, regarding the positions
and/or relocation of utilities and services, and he shall make this information available to RMC /
PMC (Project Management Consultant) as soon as he obtains it. The Contractor shall take at his
own expense, steps necessary to protect and safeguard any drains, pipes, cables and similar
services encountered, already installed or to be installed, for the duration of the Contract in
order to keep them in good working condition.
The contractor shall establish accuracy in relation to the present condition and character of the
existing structures, roadways, embankments and particulars of drains, pipes, cables, etc, and
inform the same to RMC / PMC. All locating work shall be carried out atleast four weeks in
advance of execution of the work under intimation to RMC / PMC. The Contractor shall obtain all
information and assistance available from the Utility Authorities for locating the mains and
services. Necessary trial excavations which may be required to confirm or establish these
locations shall be done by the contractor. All costs for executing trial holes shall be borne by the
contractor.
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The absence of such information shall not relieve the Contractor of this liability for the cost of
any repair work necessitated by damage caused by him to such mains and services in the course
of his work and for the cost of all losses arising from their disruption. Any temporary or
permanent diversion and/or relocation of mains and services will only be permitted after
agreement with the appropriate Utility Authority and the approval of the RMC / PMC.
Traffic Control: The Contractor shall maintain vehicular and pedestrian traffic during all work
operations and for the duration of the project. It is the responsibility of the Contractor to apply
for and obtain all necessary permits from the traffic authorities. Protection of vehicular and
pedestrian traffic shall be the sole responsibility of the Contractor. A comprehensive Traffic
Management Plan is required to be prepared by the Contractor at the onset of construction and
get it approved from RMC / PMC and local traffic authority. The Traffic Management Plan shall
include preparing and installing Signage Boards, Informatory Signs, Warning Signs, etc, for the
safety of road users. The approved Traffic Management Plan shall be fully implemented by the
Contractor, during the entire construction period so as to avoid inconvenience to the city
population. Contractor shall employ necessary manpower with full safety gears, clothing /
uniform, etc.
Cleanup and restoration of sites: During the progress of the work, it shall be the responsibility of
the Contractor to keep the premises and the vicinity of the work clear from unsightly and
disorderly piles of debris. Suitable locations shall be specified for the various construction
materials and for debris. The materials shall be kept in their storage locations, except as needed
for the work and debris shall be promptly and regularly collected and deposited in the specified
location in an environment friendly manner. Upon completion of laying of section of pipeline
and appurtenances, following acts shall be the responsibility of the Contractor;
� Grade the ground adjacent thereto, removing all surplus excavated material, leaving the area
free from surface irregularities as per specifications.
� Dispose of all surplus material, dirt, and rubbish from the site; and shall keep the site free of
mud and dust as per specifications.
� The contractor may be required to flush or sprinkle the street to prevent dust nuisance as
per specifications.
When working on the shoulders of paved roads, the Contractor shall keep the pavement clean of
all loose earth, dust, mud, gravel, etc., and shall restore road surfaces, shoulders as per the
specifications of works. After all work is completed, the Contractor shall remove all tools and
other equipment, leaving the site free, clean, and in good condition. The Contractor shall keep
the surface over and along the trenches and other excavation in a safe and satisfactory condition
during the progress of the work. He shall be held responsible for any accidents that may occur
on account of the defective condition of such surface.
12.4 Standards for Construction
All the construction works, whether civil, electrical or mechanical, shall conform to the latest
standards published by the Bureau of Indian Standards. The following order of precedence is
suggested for construction works, material test and inspection.
� Written specifications in the contract document.
� Bureau of Indian Standards / CPHEEO / JNNURM recommendations.
� Chhattisgarh State Public Health Engineering (PHE) Department specifications or equivalent
documents currently followed by CGPHED.
� Chhattisgarh State Public Works Department (CGPWD) specifications.
� British Standards.
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� American Society of Testing Materials (ASTM).
� American Association of State Highway and Transport Officials (AASHTO).
12.5 Testing
During construction all material (pipes, specials and equipments) shall be subject to testing as
per the contract specifications. The quality assurance plan for the pipe components of sewerage
system is placed below. The option of ‘Third Party Inspection’ rest with RMC and if envisaged,
the cost of same has to borne by RMC.
12.5.1 Tests on Completion
For works like sewage pumping station and sewage treatment plant, when the plant is
completely constructed / erected on site and ready for operation, it shall be tested and
commissioned under supervision and subjected to the prescribed Tests on Completion to
demonstrate that it is capable to perform its specified duties satisfactorily under the approved
system of operation and control and that the whole conforms to the Specification.
12.6 Project Management: Construction Stage
This phase of project cycle, envisages execution of works as per the final approved designs and
drawings. The objectives of project management are aimed to assist RMC to implement the
project in conformity with:
� Best project management practices as per global standards, Contract condition, Local laws,
byelaws, regulation, rules, etc.
� To ensure that the project is implemented up to the last detail for physical completion of the
project.
� Observe due diligence and prevailing standards in the performance of assignment.
� Accuracy, quality of workmanship, safety of the works being carried out by the contractors.
Ensuring safety of running traffic during execution of work.
� Completion of work in the prescribed time schedule.
� High standards of quality assurance in the execution of works.
� Implementation of environmental mitigation measures
� Implement modern methods of contract management and construction supervision,
ensuring professional construction supervision adhering to quality, target completion dates,
compliance with the drawings, technical specifications and various requirements of the
work’s contract documents including safety.
� Assist the Contractor and the Employer for the required coordination with the Authority and
any other agency including arranging traffic blocks, approval of working plans till closure of
the project,
� The application of reasonable and consistent design requirements during construction in
conformity with standard practices, and resolution of contractual claims and disputes.
� Minimizing claims disputes and assist in resolving them.
A comprehensive project management manual is being prepared for the execution of this
project. The manual will contain roles and responsibilities of the supervision staff, forms for
information collection, daily records, non-conformities, etc. The manual will be approved by
RMC before the onset of construction work. Few sample formats proposed to be used during
the construction are placed at the end of this Chapter.
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12.6.1 Production of Pipes / Manholes at Site
The complete sewer pipe network to be laid is about 1032 km. Considering this enormous
quantity of pipes, it is recommended that the Contractor shall set suitable sized RCC Socket &
Spigot (NP2 & NP3) pipe manufacturing and pre-fab RCC manhole casting unit at Raipur to meet
the project requirement. The manufacturing unit shall produce pipes confirming to relevant IS
standard for pipe quality. The unit shall also have facilities for testing of pipes.
For pre-fab manholes, the Contractor is required to submit approved design (approved by
renowned national / international academic or research institute) before producing prefab
components. A condition to this effect is also incorporated in tender documents.
Raipur Municipal Corporation shall provide land to the Contractor at mutually agreed terms &
conditions for setting the manufacturing unit at Raipur. This will save on the cost of project by
eliminating enormous transportation costs, as the nearest unit of capable / manufacture
suppliers is not less than 300 km from project site, thus enabling timely completion of project.
The Contractor shall maintain at all times a minimum inventory of 10% of various pipe sizes
required for execution, so as to avoid delay in execution of works.
12.6.2 Contractor to Produce Designs
During the preparation stage of Contractor’s work schedule for execution of sewer network
laying, extension of network or inclusion of new network branches is considered necessary by
the RMC / PMC, then the hydraulic design and drawings for the same shall be prepared by
Contractor. All such designs and drawings shall be submitted to RMC / PMC for approval, well in
advance. The cost of preparation of all such designs and drawings shall be borne by the
Contractor. A condition to this effect will be incorporated in tender documents.
12.6.3 Software for Project Scheduling and Monitoring
It will be mandatory for the Contractor to obtain licensed copy of ‘Primavera’ project
management software for scheduling and monitoring the progress of project activities. The
Contractor shall be responsible for providing trained staff for operating / use of this software. If
the Contractor fails to procure the software and or trained staff for use, than the RMC / PMC
shall procure the software and engage an expert from market to use the software and all the
expenditure on procuring software, manpower, training, etc shall be recovered form the
Contractor.
12.7 Project Implementation
Considering the magnitude and cost of works, the project is divided into two packages, namely;
• Construction of gravity sewer system plus pumping stations and laying of rising mains
• Construction of sewage treatment plants
The bid documents are prepared separately for each construction package based on the sample
bidding documents as discussed and agreed by RMC. Drawings shall be in sufficient details to
suit the construction purpose. The bid documentation shall include the following:
� Conditions of Contract and instruction to bidder.
� Technical specifications along with particular specification prepared specially for this project
� Bill of Quantities (BOQ)
� Tender Drawings
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In addition to these, the following information shall be sought from the prospective Contractors:
� Detailed presentation on methodology of project execution including deployment of man-
power and machinery and projected cash flow.
� Lay-out plan for their temporary facilities.
� Quality Assurance plan.
� Safety plan
� Environmental Mitigation plan.
� Names of proposed vendors for piping, accessories and project equipment.
� Plan for restoration of sites including roads, etc., after completion of the project.
In order to select the right type of Contractors and the project execution to be smooth, it is
proposed to include certain provisions in the contract, some of which are given below:
� Rejection of tenders with abnormally high or abnormally low prices.
� Payment of advance against deployment of construction equipment and machinery in
addition to mobilization advance.
� Introduction of a Bonus Clause.
� Third party inspection of piping, accessories and project machinery by reputed inspection
agencies.
� Weightage to the technical superiority of the bids in addition to prices for award of work
based on criteria decided in consultation with RMC.
12.7.1 Implementation Schedule
The implementation schedule for complete sewerage scheme is proposed in two major groups,
i.e. Sewerage System & SPS and STPs is presented in Annexure-7. The gravity sewerage network,
sewage pumping stations and sewage treatment plant is to be implemented in 28 months.
The Contractor shall submit work schedule using primavera software. The schedule shall be
approved by RMC / PMC at the onset of construction activities. The Contractor shall make use of
supporting S-curve charts, CPM / PERT charts, Bar charts, etc.
The schedule to be presented during kick-off meeting shall contain the following, but not limited
to:
• Project Management Plan
• Construction Schedule
• Manpower Schedule
• Resources Schedule
• Cash Flow Statement
• Schedule of Equipment & Machinery
• Quality Assurance Plan
• Quality Control Plan
• Site Organisation Chart
• Site Laboratory
***
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REQUEST FOR INFORMATION
Project Code / Name : Document No…………..
Client Code / Name :
Contractor Code :
Location / Section :
Request for Information No:
………………………………
Date:
…………..
This Request for Information will constitute
Issued to,
Attention :
Designation : Variation Order
(VO)
Extension of Time
(EOT)
Remedial Action
.
Information Required
Dead line: ………………….
Issue By : Acknowledgement of Receipt :
Name : Name :
Position : Date :
,
Response
Attachments / Response :
Signature :
Name :
Position :
Date :
Company Stamp:
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RECEIVING INSPECTION CHECKLIST
Project Code / Name :
Client Code / Name :
DEPMC / Contractor Code :
Location / Section :
Supplier : Delivery Order No :
Delivery Date : Purchase Order No :
The following items have been checked : Acceptability
Yes No
1. Type / Grade
2. Dimensions / Sizes
3. Quantity received
4. Any damaged / poor quantity items
5. Any item to be rejected? If yes, state the quantity?
.
Remarks :
Test Status :
Acceptable
Reject
Downgrade
Checked by
Signature :________________
Name :
Date :
Approved by
Signature :_________________
Name :
Date :
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WORKS INSPECTION CHECKLIST
Structural Work (RCC / Concrete) Inspection
Project Code / Name :
Client Code / Name :
DEPMC / Contractor Code :
Location / Building Block :
Drawing Ref. :
Items to be checked:
No Checklist Contractor Consultant
Yes No Yes No
1 Formwork setting out/dimensions
2 Formwork verticality
3 Formwork thickness / stability / prop
4 Fixing to structures
5 Main bars
6 Secondary bars
7 Links / Stirrups
8 BRC
9 Starter bars / lapping / anchorage
10 Covers
11 Levels / drops
12 Rebars / BRC clean, free of dust etc.
13 Water proofing membrane
14 Conduits / Services / Opening / Piping
15 Preparation on wet weather & curing
STATUS Checked by
DEPMC/ Contractor
Approved by
Consultant / Client
Acceptable Signature :
Unacceptable
Down-Grade Name :
Reject Date :
Revision: Issue: Effective Date:
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Sewerage Reticulation Works Inspection Checklist
Project Code : Package No :
Contractor Name :
Location / Zone :
Ward no. :
Drawing Ref. :
Items to be checked:
No Checklist Contractor Consultant
Yes No Yes No
1 Pipe alignment / location / levels
2 Pipe size as per drawings
3 Pipe laying, jointing & fitting
4 Approved RCC/DI pipe & Accessories
5 Excavation and strutting
6 Valve installation
7 Position of pipe sleeves correct
8 Bedding /haunching
9 Backfilling materials / compaction
10 Straightness Test
11 Leakage Test
12 Smoke Test
13 Pump & accessories
Remarks:
Status Contractor Consultant Client
Acceptable Signature :
Downgrade
Unacceptable Name :
Revision No: Date :
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Cost Estimates 11113333
13.0 Cost Estimates
13.1 Basis of Cost Estimate
The following schedule of rates are adopted is costing of various work components for this
project.
• Chhattisgarh State SOR for PHE works as adopted since 01-09-2002.
• CPWD - Delhi Schedule of Rates,2007
• Madhya Pradesh State SOR for PHE works as adopted since 02-12-2009.
Sewers: The quantities of a typical sewerage system comprise earthwork for excavation in
trenches, quantity of bedding material, quantity of pipes of various diameters, quantities of
manholes of different configuration, finishing, dewatering, disposal of surplus material, shoring,
road restoration, etc. The corresponding rates for these quantities are adopted from PHED-USR,
2002. Where the corresponding basic rates were not available, the rates as mentioned in
CGPWD or CPWD, Delhi Schedule of Rates, 2007, with updated cost index are adopted.
Sewage pumping stations: The cost of sewage pumping stations, sizing of wet well is considered
to arrive at cost of RCC work. The cost of civil works is taken as Rs. 8000 per cum. The cost of
rising main is worked out on the basis of economic diameter analysis as per CPHEEO guidelines
and pipe material for rising main is DI (K7). The cost of DI (K7) is as per the circular of CE, PHE-CG
State, dated 11-09-2007. The associated accessories (valves, chamber, etc) is taken at 10% of
pipe cost. The cost of pumping machinery is considered on KW basis and is taken at Rs.20000 per
KW. The other costs related to laying of rising main are worked out on the basis of CG-PHE
USR/CPWD-DSR adopting the approach as described above for gravity network. The cost
estimate is presented in separate Volume - IV: Cost Estimates.
Sewage Treatment Plant: The cost of sewage treatment plant is based on the hydraulic sizing of
treatment units, sludge handling system and utility works like, administrative building, blower
room, MCC and control room, HT sub-station house, DG set house, staff quarters, security
shelters, internal roads and pathways, boundary wall, etc. The treatment plant cost is also
inclusive of mechanical, electrical and instrumentation works. The summary of cost is presented
in separate Volume - IV: Cost Estimates.
The O&M cost of STP and SPS is worked out using following formula as mentioned in CPHEEO
manual.
Annualized Capital Cost = Annual O&M Cost x [{1-(1+ r)-n
} / r]
Where;
r = rate of interest, presently taken as 4%
n = number of years over which cost is annualized, (3 years)
Annual O&M cost is considered as 4% and 5% of Capital Cost for Sewage Treatment Plants and
Sewage Pumping Stations respectively.
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Other costs: The cost of providing house connections with PVC pipe, implementing
environmental management plan is also under this head. The expenditure towards relocation of
utilities, if required, is provided as lumpsum cost. The cost towards land acquisition for SPS, STP
and access road to STP is also included.
In the gravity sewer network costs, 3.5% of the amount is kept for provisions of encasing and
protection works as and when required during construction. This percentage cost is derived from
the total cost associated with providing and laying of pipes only.
To cater for the costs related to unforeseen contingencies during construction phase and
departmental charges to be incurred for the execution of job, 6% cost is provided on total cost.
13.2 Price Escalation
For items of works the rates prevailing in existing SOR of PHE are updated with current cost
index. Since the scheduled item rates are about eight year old and to update these rates to
current level, cost indices for material, labour and POL are updated. The percentage escalation
arrived is 64%.
Note: During the Bilaspur Sewerage scheme, a circular was issued by CE, PHE, CG (Annexure-8)
State promulgating escalation percentage for PHE works in CG state as under;
• 33% above SOR for pumping mains
• 38% above SOR for distribution system
The nodal agency shall circulate a similar communication to the effect that 64% escalation is
applicable to this project.
13.3 Detailed Cost Estimate
The detailed cost estimates for network of trunk, sub-trunk, collector and lateral sewers of 1032
kms, 13 Nos. SPS and 3 Nos. STPs are presented in Volume - IV. The estimates are under the
following categories.
1. Gravity pipe laying, Restoration of road works, complete.
2. Providing PVC pipe connection form property to manhole.
3. Sewage pumping station and related works including rising main, E&M plant and 3 years
O&M cost.
4. Sewage Treatment Plant and related works including 3 years O&M cost.
5. The environmental costs associated with the project to implement the Environmental
Management Plan.
Particular Description Cost
Sewer Network Zone-I+II+III (142 km2) Rs. 57326.72 Lakhs
Pumping Stations 13 Nos. Rs. 2198.35 Lakhs
Treatment Plant 209 MLD Rs 20482.00 Lakhs (w/o O&M)
Land Acquisition 29.40 + 0.71 ha Rs. 32.41 Lakhs
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The abstract summary of cost is presented in Table 13.1.
Table 13.1 : Abstract of Cost
Sr.
No. Description Amount
A SEWER NETWORK
ZONE - I
1 Trunk No.1 279494438.00
2 Trunk No.2 531315919.00
3 Trunk No.3 401350543.00
4 Trunk No.4 127018741.00
5 Trunk No.5 127051907.00
6 Trunk No.6 114401356.00
7 Trunk No.7, 8 & 9 382993721.00
8 Trunk No.10 & 11 221725212.00
Subtotal (ZONE-I) 218,53,51,837.00
ZONE – II
1 Trunk No.1 62112743.00
2 Trunk No.2 167880494.00
3 Trunk No.3 426731298.00
4 Trunk No.4 89109501.00
5 Trunk No.5 50209393.00
6 Trunk No.6 136586343.00
7 Trunk No.7 251803816.00
8 Trunk No.8 & 9 387160208.00
Subtotal (ZONE-II) 157,15,93,796.00
ZONE – III
1 Trunk No.1 156745444.00
2 Trunk No.2 811258860.00
3 Trunk No.3 233570644.00
4 Trunk No.4 55936605.00
5 Trunk No.5 324324835.00
6 Trunk No.6 80028278.00
7 Trunk No.7 130357164.00
8 Trunk No.8 79287266.00
9 Trunk No.9 104218262.00
Subtotal (ZONE-III) 197,57,27,358.00
Total (A) 573,26,72,991.00
B SEWAGE PUMPING STATION
1 ZONE-I: SPS-A Mahatma Gandhi Nagar, (Near
Chhokra Nallah) – 1.10 MLD 5692929.00
2 ZONE-I: SPS-B Lav-Kush Vatika, Ajuba Park, (Near
Chhokra Nallah) – 3.37 MLD 6639803.00
3
ZONE-I: SPS-C Labhandi Village, Near Ryan
International School, (Near Chhokra Nallah) – 8.23
MLD
15570877.00
4
ZONE-I: SPS-D Shastri Nagar, Near Central Ware
Housing Corporation, (Near Raman Mandir/Shastri
Nagar Nallah) – 14.87 MLD
20640710.00
5 ZONE-I: SPS-E Near Daldal Seoni Oxidation Ponds,
(Near Mova Nallah/ Chhokra Nallah) – 87.09 MLD 30521435.00
6 ZONE-II: SPS-A At Existing Khamtarai Sewage 26596684.00
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Table 13.1 : Abstract of Cost
Sr.
No. Description Amount
Pumping Station – 71.79 MLD
7 ZONE-II: SPS-B At Tahbandh-Bilaspur Road (Near
Bhanpuri Chowk) – 11.65 MLD 10268472.00
8 ZONE-II: SPS-C Near Railway Diesel Depot – 6.03
MLD 13315572.00
9 ZONE-II: SPS-D Near Rameshwar Nagar – 8.11 MLD 17711879.00
10 ZONE-II: SPS-E Near G.K Motors (Eicher) at
Tatibandh- Bilaspur Road – 7.91 MLD 21504530.00
11 ZONE-II: SPS-F Near Chhota Bhawani Nagar Kota –
29.76 MLD 26596684.00
12 ZONE-III: SPS-A Near Mahanta Talab,Hanuman
Temple – 4.25 MLD 10677317.00
13 ZONE-III: SPS-B Math Puraina Area Near Jyoti Nagar
Chowk – 6.11 MLD 14098473.00
14 O&M COST FOR 3 YEARS 26400373.00
Subtotal (B) 24,62,35,738.00
C SEWAGE TREATMENT PLANT
1 ZONE – I : 65 MLD SBR PLANT @ Rs.98Lakhs / Mld 637000000.00
2 ZONE – II : 67 MLD SBR PLANT @ Rs.98Lakhs / Mld 656600000.00
3 ZONE – III : 77 MLD SBR PLANT @ Rs.98Lakhs / Mld 754600000.00
4 O&M COST FOR 3 YEARS 196777232.00
Subtotal (C) 2244977232.00
D OTHER COSTS
1 PVC pipe connections (For House Connections) 513491833.00
2 Relocation of Utilities 10000000.00
3 Implementation of EMP 2500000.00
4 Land Acquisition Cost for STP/SPS 3241013.00
Subtotal (D) 529232846.00
E Subtotal (A+B+C+D) 8753118807.00
F Contingencies & departmental charges @ 6%
on E above 525187128.00
G
GRAND TOTAL (E+F)
927,83,05,935.00
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13.4 Summary of Costs
The summary of costs for various components of the project is presented below in Tables 13.2.
Table-13.2: Summary of Costs
Sr.
No.
Item Cost (Rs.)
Crores
Remarks
1
Sewerage system complete with laterals,
collectors, interceptor sewers + 13 Nos of Sewage
Pumping Stations with DI rising main and all
accessories complete
595.250
1032 km of
gravity sewers
150 – 2200 mm
diameter
2
3 Sewage Treatment Plants on SBR technology
complete in all aspects (zone-I : 65 Mld, zone –II:
67 Mld and zone-III: 77 Mld)
204.82 Only construction
cost
3 O & M Cost for SPS and STP 22.411 cost of O&M of 3
years
4
Land Acquisition Cost for 30.11 hac (for all 3 STPs
& 11 SPS)
0.3241 @ Rs.1 per sq.ft.
5 Environmental Mitigation and Monitoring Cost 0.25
During
construction stage
6 Relocation of Utilities 1.00 Provisional LS
item
7
House Connections for 82200 as per CDP of Raipur
51.349
75000 domestic,
5000 commercial,
2200 industrial
TOTAL 875.3118
Adding 6%* for Contingencies and Departmental
Charges of Total Cost 52.923
Total Cost (Rs. in Crores)
927.830
* percentage approved under Bilaspur Sewerage Project
The cost details are worked out assuming that the land required for all the three STPs is to be
acquired. However, the STP location for Zone-II remains unchanged from the existing one (i.e.,
oxidation ponds at Rawabhata). Similarly, during the field survey for Zone-I STP, the new
proposed location has been shown to be government land. However, the total cost for land
acquisition is very marginal (Rs. 32.41 Lakhs) as compared to other components.
13.5 Cash Flow Statement
On the basis of implementation schedule the 1st year of implementation would require Rs.
382.23 crores for expenditure and 2nd year would require Rs. 220.27 crores. The funds to be
required for execution of works are split in to monthly requirement as per the implementation
schedule of works. The expenditure on sewerage network, SPS, house connections and other
works is combined together at Rs. 647.849 Crores. The expenditure on STP is Rs. 204.82 Crores.
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The above costs are exclusive of 6% departmental charges and contingencies. The cash flow
statement is placed at Annexure-7.
***
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Financial Analysis 11114444
14.0 Financial Analysis
14.1 Financial Management
The Capital cost refers to the initial outlay of money required to acquire and install the
technology in a user’s facility. It includes all the costs incurred up to the point that the
technology is ready to perform its desired function in the user’s facility. Capital items include
construction, purchased equipment, installation and other initial investments associated with
the technology.
The major capital cost in this project is for laying of 1032 kms of gravity sewers ranging from 150
mm to 2200 mm diameter. Though the sewer laying is for the betterment of population of
Raipur, but at the same it is the responsibility of RMC to recover the cost of project from the
population benefited by the project. Unlike water supply schemes, where water is charges to the
consumers who are connected to piped water supply, sewerage connections perform poor in
terms of realization of user charges. The CDP targets for providing 75000 domestic sewer
connections, 5000 commercial and 2200 industrial connections by year 2012-2013.
It becomes compulsory for RMC to provide these connections and steadily increase the
connectivity on sewer system, so as to achieve 100% sanitation and thus improve the functional
efficiency of the assets thus created under this project. Based on the proposed connectivity
targets, the revenue generation and expenditure analysis is separately presented as Volume- 1A
: Financial Analysis, with this report.
14.1.1 Tariff Charges
Sewerage is a service that is provided after incurring costs and hence needs to be charged. It is
also important that RMC initiates the policy and procedures of charging for proposed sewerage
system at this project initiation stage. On implementation of both water supply and sewerage
schemes, the sewage treatment charges have to be fixed in the ratio of revenue collected from
different users for water supply. The charges could be based on expenditure incurred on
providing the system. Charge for sewerage shall be levied to only those households which shall
be connected to the sewerage system. RMC shall develop the various tariff categories during the
course of our services, which shall reflect the types of charges which can be levied on different
service groups. Tariff shall be linked to other variables like power charges and consumable
charges and shall subject to annual increase by certain percentage automatically or in
correlation to increase in variable charges.
14.1.2 Public-Private-Partnership
Public Private Partnership (PPP): In public private partnership concept, a private company
renders public utility service on the grounds of a contract with a public institution which is
responsible for these services. Quite often this is executed according to the BOT - build-operate-
transfer formula, which means that e.g. a company lays a gas pipe network, and then collects
the fees for several years for supplying gas, thus getting the return on investment, to eventually
hand it over to the local government. For private companies, PPP is an opportunity for big
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contracts, and for institution it is a chance to implement large investment projects, which
otherwise would be impossible due to limited financial resources.
The sanitation services (especially sewerage system) for community is perceived as civic
responsibility where in revenue generation out of service provided is not the objective.
However, in India, the public-private partnership is now a decade old concept and many water
supply and sewerage authorities / ULBs are exploring the options for bringing the services under
PPP model. The following successful projects in water supply and sanitation have already been
carried out:
� Tirupur water supply project
� The Alandur Sewerage Project
In PPP cases, two stage approach is followed which covers the aspects as hereunder;
� Development stage
• Assessment of revenue (water and sewerage)
• Verification of leakages (water)
• Assessment of pre-operating costs, capital required, O&M
• Repayment of debt
� Tendering process / selection of Private Sector Partner stage
• Technology tie-ups
• Capital Costs, O&M Costs
• Financing structure
• Delivery commitments
Since this project is envisaged for funding by JNNURM and/or external agency. An illustrative list
of service which has the potential for PPP in case of Raipur is given below.
� Sewerage network (collection system)
� Pumping station (installation and O&M)
� Disposal System (through water recycle – based on water demand)
A separate study is required to arrive at the options for PPP involvement in this project.
14.2 Conclusions
Implementation of this project is envisaged in 28 months in which the sewerage network laying,
SPS and STP shall be completed. At the time, centralized sewerage system comes up, the
individual house hold shall have the facility to connect their soil and waste pipes to the
centralized sewerage system.
It is the prime responsibility of RMC to make a detailed tariff plan considering the improvement
in the civic infrastructure of the city. The tariff plan should be prepared in line so that the
expenditure of O&M is covered and future reserve fund is available for any future expansion.
RMC should focus on bringing in a new unified tariff structure for water and sewerage services
immediately. Focus should be on reforms aiming at providing sustainability of services at least
for the O&M component. Following conclusions are brought out for consideration of RMC.
� Privatize the sanitation services through Concession Agreements;
� Immediate augmentation of water resources;
� Water conservation through an appropriate tariff structure;
� Formulate Policies to attract and support Private sector participation;
� Develop water policy guidelines;
� Set up an Independent Regulatory Authority; and
� Rationalize tariffs.
***
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Conclusions and Recommendations 11115555
15.0 Conclusions and Recommendations
15.1 Conclusions
The Capital cost refers to the initial outlay of money required to acquire and install the
technology in a user’s facility. It includes all the costs incurred up to the point that the
technology is ready to perform its desired function in the user’s facility. Capital items include
construction, purchased equipment, installation and other initial investments associated with
the technology.
The following conclusions are arrived at:
• The sewage generation rate is calculated at 80% of water supply (using 135 lpcd water
supply rate).
• The area-density method is being adopted to compute the load of flow on each lateral.
• The economic analysis reveals that DI pipe are more economical diameter / cost wise
and they also give better velocity and smaller diameter.
• The zoning is based on topographical features (slope, water bodies, etc.) of the area and
location of treatment / final disposal point. Topographically, almost 56% of project area
is having slope from south to north direction.
• Population for the project is projected as 10.14 lakhs in year 2012, 19.33 lakhs in year
2027 and 26.94 lakhs in year 2042. The year 2042 population is inclusive of additional
10% population.
• Sewage flows year 2012, 2027, 2042 are 109.59 Mld, 208.81 Mld and 290.96 Mld
respectively.
• The minimum velocity is kept as 0.45 m/s in the initial reaches of lateral sewers.
• Minimum diameter of sewer adopted in design is 150 mm.
• RCC NP2 and NP3 pipes are proposed in design.
• The depth of sewer laying is limited at 7 to 8 m, and an intermediate sewage pumping
station is proposed at such location.
• The total gravity sewer length proposed is 1032 km.
• 13 submersible pump type sewage pumping stations are proposed to facilitate
conveyance of sewage up to the proposed treatment facilities.
• The CDP targets for providing 75000 domestic sewer connections, 5000 commercial and
2200 industrial connections by year 2012-2013.
• Cost of sewerage system is computed at Rs. 927.83 Crores
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15.2 Recommendations
• RCC pipes (NP2 and NP3) are cost wise most economical for all manufactured diameter
ranges. Hence for gravity sewers, it is prudent to adopt RCC pipes because of their low
cost and wide availability.
• SBR technology based STPs are recommended based on life cycle cost analysis, at three
locations with 65 Mld , 67 Mld and 77 Mld capacity.
• RMC to identify potential areas for application / reuse of treated effluent, as the SBR
treated effluent will be of very high standards.
• STPs are proposed to be constructed on EPC basis with functional guarantee from
contractor / technology provider along with 3 years O&M.
• All 13 sewage pumping stations to be constructed with submersible pump type
configuration and circular wet well and dry room above.
• Space of 2 existing SPS will be utilized for construction of new SPS at the same location.
• Space for 1 STP (zone – II, at Rawabhata) will be utilized at existing Oxidation Ponds site.
• All pumping stations and STPs will have DG sets to operate 50% capacity of the units.
• Process for land acquisition to be initiated immediately to avoid time over-run
while executing the works.
• RMC to prepare scheme for providing house connections so that when the sewer system
is commissioned in year 2012, connectivity of 82,200 domestic and commercial units is
available.
• Works for construction to be packaged in two parts, namely, sewer pipelines + SPS and
Sewage treatment plants.
ANNEXURES
Annexure - 1
Annexure - 1 Ward Wise Area Statement for Raipur Municipal Corporation
Ward
No.
Area, Acres Area, KM2 Ward
No.
Area, Acres Area, KM2
1 3552.19 14.38 36 138.69 0.56
2 1277.63 5.17 37 138.48 0.56
3 326.26 1.32 38 73.08 0.30
4 1348.62 5.46 39 51.64 0.21
5 674.66 2.73 40 172.52 0.70
6 1026.61 4.15 41 96.02 0.39
7 268.34 1.09 42 219.88 0.89
8 189.27 0.77 43 177.08 0.72
9 264.47 1.07 44 149.61 0.61
10 108.55 0.44 45 496.38 2.01
11 158.24 0.64 46 1845.49 7.47
12 391.28 1.58 47 138.43 0.56
13 467.41 1.89 48 177.41 0.72
14 901.77 3.65 49 186.79 0.76
15 333.31 1.35 50 232.84 0.94
16 108.50 0.44 51 646.20 2.62
17 156.49 0.63 52 1080.19 4.37
18 114.25 0.46 53 116.80 0.47
19 49.04 0.20 54 257.56 1.04
20 176.34 0.71 55 48.32 0.20
21 136.44 0.55 56 62.36 0.25
22 102.98 0.42 57 154.27 0.62
23 214.14 0.87 58 50.98 0.21
24 113.99 0.46 59 24.43 0.10
25 145.26 0.59 60 255.63 1.03
26 2450.25 9.92 61 96.98 0.39
27 2637.94 10.68 62 361.30 1.46
28 1444.19 5.84 63 2352.86 9.52
29 233.61 0.95 64 131.22 0.53
30 142.74 0.58 65 77.25 0.31
31 97.09 0.39 66 196.64 0.80
32 186.49 0.75 67 405.65 1.64
33 112.14 0.45 68 1462.26 5.92
34 121.12 0.49 69 572.84 2.32
35 245.15 0.99 70 1749.03 7.08
TOTAL 34673.89 140.32
ANNEXURES
Annexure - 2
Annexure - 2 Ward Wise Population Projections for Raipur Municipal Corporation
Ward
No.
Population,
2012
Population,
2027
Population,
2042 Ward
No.
Population,
2012
Population,
2027
Population,
2042
1 16038 30561 38712 36 14456 27546 34894
2 16531 31499 39901 37 14648 27911 35356
3 16536 31509 39914 38 16102 30683 38867
4 16441 31328 39685 39 12394 23617 29916
5 15210 28982 36713 40 12668 24139 30578
6 13181 25116 31815 41 12620 24048 30462
7 15745 30002 38005 42 16164 30800 39016
8 16266 30994 39261 43 16390 31231 39562
9 15196 28957 36680 44 16042 30568 38722
10 16230 30925 39174 45 13461 25649 32491
11 13932 26547 33628 46 13552 25823 32710
12 15233 29025 36768 47 14178 27016 34222
13 15030 28640 36280 48 16060 30601 38764
14 13180 25114 31812 49 15013 28607 36238
15 15186 28936 36654 50 12671 24145 30585
16 14070 26809 33960 51 13901 26488 33553
17 12935 24647 31221 52 14865 28324 35879
18 15939 30372 38473 53 16260 30984 39248
19 15524 29581 37472 54 12995 24762 31366
20 16199 30867 39100 55 15473 29484 37349
21 12707 24213 30672 56 13730 26162 33140
22 13451 25631 32468 57 12624 24055 30472
23 13758 26215 33208 58 12891 24563 31114
24 13451 25631 32468 59 12782 24356 30853
25 13847 26386 33424 60 13291 25325 32080
26 16017 30520 38660 61 13873 26435 33486
27 14186 27031 34241 62 14462 27557 34907
28 16635 31698 40153 63 16396 31242 39575
29 13936 26554 33637 64 15320 29191 36977
30 12402 23632 29935 65 12801 24392 30898
31 13728 26159 33137 66 13295 25333 32090
32 14361 27365 34665 67 15386 29319 37139
33 13252 25251 31987 68 12952 24680 31263
34 13870 26429 33479 69 13918 26521 33595
35 14294 27238 34503 70 16545 31527 39936
TOTAL 1014676 1933452 2449169
ANNEXURES
Annexure - 2
POPULATION PROJECTION FOR THE PROJECT
A. Introduction about Demography
The first settlement of Raipur city was the Raipura village, near Mahadev Ghat on the bank of Kharun River.
The second one came up close by at Purani Basti and the third settlement emerged as Budhapara along the
Budha talab, which served as the major source of water for the people. Contrary to the present position,
during the beginning of the 9th
century the town has considerably expanded more towards south and west,
and extended right up to Mahadev Ghat.
In 1867 the Municipality was created in Raipur. The Municipality was reconstituted in 1883, 1903 and 1925-
26 under the Central Provinces and Berar Municipality act of 1922. In 1909, Gole Bazar was made by Colonel
Twyford. In 1951, the total area of Raipur Municipal Council was 8.0 square miles occupied by 16,823
residential houses. The area increased to 9.72 square miles or 25.17 square kilometers, while the number of
occupied houses arose to 25,785 in 1961.
Raipur was the seventh largest town of the Central Provinces with a population of 24948 in 1881, the
number went up to 32114 in 1901 and now after hundred years the population is touching around 7.0 lakhs.
Raipur is the largest city in the state with a population of 6,70,042 souls as per year 2001 census. The census
data on decadal population since year 1881 is presented in Table A-2.1 below.
Table A-2.1: Decadal Population Data for Raipur City
Sr. No. Census year Population, Souls
1 1881 24,948
2 1891 23,759
3 1901 32,114
4 1911 35,335
5 1921 38,341
6 1931 45,390
7 1941 63,465
8 1951 80,804
9 1961 1,39,792
10 1971 1,74,518
11 1981 3,38,000
12 1991 4,61,000
13 2001 6,70,042
Source: Sewerage Report 1976 & CDP for Raipur City
B. City Development Plan (CDP) of Raipur City
The Population that has been taken for CDP pertains to population of Municipal Corporation area as per
census 2001. In the year 2003, 26 villages were brought under Raipur Municipal Corporation (RMC). These
villages had a population of 88139 as per 2001 census and were added as 16 Wards under RMC. The growth
rate for projecting the population of these villages for the year 2003 has been taken at 2.01% (The growth
rate for rural population in Madhya Pradesh between 1991-2001). Considering that population the
projection has been done for 2005 to 2021. The average annual growth rates of Raipur city between year
1981 and year 2011 are given in Table A-2.2.
Table A-2.2: The Average Annual Growth Rates of Raipur city
Sr. No. Year Population Average Annual Growth
Rate (%)
1 1981 3,38,000 5.07
2 1991 4,61,000 3.15
3 2001 6,70,042 3.81
4 2005 (estimated) 8,66,545 3.48
5 2011 (projected) 10,64,045 3.48
Note: Population projection has been done using Compound Growth Rate Method
Source: CDP for Raipur City, Section 2.1, Page15.
ANNEXURES
Annexure - 2
The city is witnessing rapid growth since it has assumed the role of capital city. The growth rate is
significantly above the average national growth rate in urban areas.
The rates of growth of population experienced by Raipur Urban Agglomeration during 1991 and 2001 will
continue in future though at a lesser rate. The projections given in CDP indicate that the Raipur Municipal
Corporation would house a population of 10.64 lakhs in 2011 and 14.98 lakhs in 2021. The detail is shown in
Table A-2.3.
Table A-2.3: The CDP Proposed Decadal Growth Rate
Source: CDP for Raipur City, Section 2.1.1, Page18.
C. DPR of Raipur Augmentation Water Supply Scheme (DPR-AWS)
The methods used in Detailed Project Report of Raipur Augmentation Water Supply Scheme Including
Extended Area of RMC (DPR-AWS) for population projection of Raipur City are;
• Arithmetical Increase
• Incremental Increase
• Geometrical Increase and
• Average Growth Method.
The report mentions that the growth rate of the City at present and in next decade will be according to the
Geometrical manner because of the polarization of population & fast urbanization up till 2023.
The decadal population from year 1951 to year 2001 considered for population projection is mentioned in
DPR-AWS is shown in Table A-2.4.
Table A-2.4: Decadal Population for Projection
Sr. No. Year Population Increase
1 1951 89,804 26,246
2 1961 1,39,983 50,179
3 1971 1,74,518 34,535
4 1981 3,48,000 1,73,482
5 1991 4,62,000 1,14,000
6 2001 6,70,042 2,08,042
Source: DPR of Raipur Augmentation Water Supply Scheme Including Extended Area of RMC
The projected population as per the methods mentioned in DPR-AWS is given in Table A-2.5.
Table A-2.5: The DPR-AWS Estimated Population of Raipur City
Estimated Population Sr.
No.
Methods Used
2005 2008 2021 2023 2038
1 Arithmetical
Increase
7,10,474 7,40,798 - 8,92,418 10,44,038
Year Decade Growth Rate, % Population
2001 1991-2001 37.9 67,0042
2011 2001-2011 34.8 10,64,045
2021 2011-2021 34.8 14,98,216
ANNEXURES
Annexure - 2
Estimated Population Sr.
No.
Methods Used
2005 2008 2021 2023 2038
2 Incremental
Increase
7,35,925 7,94,882 - 12,12,379 18,34,396
3 Geometrical
Increase
7,78,907 8,72,014 14,22,398 15,33,603 26,97,133
4 Average
Growth
7,57,735 8,25,819 - 13,17,915 20,90,239
Source: DPR of Raipur Augmentation Water Supply Scheme Including Extended Area of RMC
Considering the decadal population presented in Table A-2.4, the population projected using Incremental
Increase and Geometrical Increase Methods for Year 2005, 2008, 2023 and 2038 is reviewed and the revised
population after incorporating mathematical/typographical errors is given in Table A-2.6.
Table A-2.6: The Estimated Population of Raipur City
Estimated Population Sr.
No.
Methods Used
2005 2008 2021 2023 2038
1 Arithmetical
Increase
7,10,474 7,40,798 - 8,92,418 10,44,038
2 Incremental
Increase
7,20,654 7,62,432 - 10,20,402 13,60,179
Differences in
population
(-)15,271 (-)32,450 - (-)1,91,977 (-)4,74,217
3 Geometrical
Increase
7,79,181 8,72,551 14,24,900 15,36,571 27,05,917
Differences in
population
274 537 2,502 2,968 8,784
4 Average
Growth
7,57,735 8,25,819 - 13,17,915 20,90,239
Further the DPR mention that after year 2023, the rate of growth of the city will be slower and the
geometrical development will not continue and semi saturation state of the town will be achieved.
A comparative statement as per CDP Raipur City highlights that the population projection in the year 2021 is
14,98,216 souls which is very near to the population forecast 14,22,398 souls (Table A-2.5) as per
geometrical increase method. Therefore, up to year 2023 the geometrical increase method is adopted and
the population considered in DPR is 15,33,603 souls (Table A-2.5).
After year 2023, the semi saturation stage in population growth will take place and the exact geometrical
growth will not apply onwards year 2023. Now, taking the realistic growth as 3.48% per annum will be
enough. Hence, this growth is considered from the year 2023 to year 2038 and the population worked out is
21,35,960 souls in the year 2038.
The above statement contradicts itself that the population by the year 2038 has been estimated as
21,35,960 souls taking the base year of 2023 at the rate of 3.48% per annum. In actuality, the population
estimated by year 2038 is taking into consideration of base year 2008 which could not be applicable
because the growth rate by the year 2001 is 37.9% (Table A-2.3).
D. Consultant’s Projection for Project
The Decadal Population considered as per DPR of Raipur Augmentation Water Supply Scheme Including
Extended Area of RMC for projection of project population as per CPHEEO methods.
ANNEXURES
Annexure - 2
Table A-2.7: The Rate of Growth of Population for Projection
Year Population Increase Rate of Growth Incremental
Increase
Decrease in
Increase
1911 - - - - -
1921 - - - - -
1931 - - - - -
1941 63,558 - - - -
1951 89,804 26,246 - - -
1961 1,39,983 50,179 0.5588 23,933 -
1971 1,74,518 34,535 0.2467 -15,644 0.3121
1981 3,48,000 1,73,482 0.9941 138,947 -0.7474
1991 4,62,000 1,14,000 0.3276 -59,482 0.6665
2001 6,70,042 2,08,042 0.4503 94,042 -0.1227
Average 101,081 0.5155 36,359 0.0271
Forecast year = 2042 Intermediate Year = 2027
Geometric Mean of Rate of Growth = 0.4583
1. Incremental Increase Method (as per CPHEEO Manual):
( ) ( )
=−
−++=
10YY
YYxPPPY
19912001
2001PAIIAI2001P
Where,
YP = Year for population projection
P2001 = Population of Year 2001 = 670042
Y2001 = Year 2001 = 2001
Y1991 = Year 1991 = 1991
PAI = Average Increase Population
PAII = Average Incremental Increase Population
( ) ( )725018
10
4x36359101081670042Y2005 =
++=
( ) ( )766250
10
7x36359101081670042Y2008 =
++=
( ) ( )807482
10
10x36359101081670042Y2011 =
++=
( ) ( )821226
10
11x36359101081670042Y2012 =
++=
( ) ( )944922
10
20x36359101081670042Y2021 =
++=
( ) ( )972410
10
22x36359101081670042Y2023 =
++=
ANNEXURES
Annexure - 2
( ) ( )1027386
10
26x36359101081670042Y2027 =
++=
( ) ( )1178570
10
37x36359101081670042Y2038 =
++=
( ) ( )1233545
10
41x36359101081670042Y2042 =
++= ;
2. Geometric Increase Method (as per CPHEEO Manual) - Suitable for City with Unlimited Expansion:
( )
+=
−−
19912001
2001PYY
YY
2001P GMR1PY
Where,
YP = Year for population projection
P2001 = Population of Year 2001 = 670042
Y2001 = Year 2001 = 2001; Y1991 = Year 1991 = 1991
GMR = Geometric mean of rate of growth
( )( )7791814583.01670042Y 10
4
2005 =
+=
( )( )8725514583.01670042Y 10
7
2008 =
+=
( )( )9771104583.01670042Y 10
10
2011 =
+=
( )( )10146764583.01670042Y 10
11
2012 =
+=
( )( )14249004583.01670042Y 10
20
2021 =
+=
( )( )15365714583.01670042Y 10
22
2023 =
+=
( )( )17868554583.01670042Y 10
26
2027 =
+=
( )( )27059174583.01670042Y 10
37
2038 =
+=
( )( )31466694583.01670042Y 10
41
2042 =
+=
3. Arithmetic Increase Method (as per CPHEEO Manual):
−
−+= tionreasPopulaAverageInc*
YY
YYPY
19912001
2001P2001P
Where,
YP = Year for population projection
P2001 = Population of Year 2001 = 670042
Y2001 = Year 2001 = 2001
Y1991 = Year 1991 = 1991
ANNEXURES
Annexure - 2
710474101081*10YY
4YY670042Y
19912001
200120052005 =
=−
=−+=
740798101081*10
7670042Y2008 =
+=
771123101081*10
10670042Y2011 =
+=
781231101081*10
11670042Y2012 =
+=
872203101081*10
20670042Y2021 =
+=
892419101081*10
22670042Y2023 =
+=
932852101081*10
26670042Y2027 =
+=
1044040101081*10
37670042Y2038 =
+=
1084473101081*10
41670042Y2042 =
+=
4. Decreasing Rate of Growth Method (as per CPHEEO Manual, City Reaches saturation):
Table A-2.8: The Decreasing Rate of Growth of Population for Projection
Year Population Increase Percent Increase Decrease in Percent
Increase
1911 - - - -
1921 - - - -
1931 - - - -
1941 63,465 - - -
1951 89,804 26,339 - -
1961 1,39,983 50,179 55.88 -
1971 1,74,518 34,535 24.67 31.21
1981 3,48,000 1,73,482 99.41 -74.74
1991 4,62,000 1,14,000 32.76 66.65
2001 6,70,042 2,08,042 45.03 -12.27
Average 1,01,096 2.71
Ultimate year = 2042 Intermediate Stage Year = 2027
−
−
−+= −
−− 1P
19912001
1PP1PP P*
YY
YY*
100
ADPI2001Y.in.increase.PercentagePY
Where,
ANNEXURES
Annexure - 2
YP = Year for population projection;
YP-1 = Previous year for population projection;
ADPI = Average decrease in percentage increase.
P2001 = Population of Year 2001 = 670042
Y2001 = Year 2001 = 2001
Y1991 = Year 1991 = 1991
783465670042*10
420012005*
100
32.4271.203.45670042Y2005 =
=−
=−+=
882932783465*10
320052008*
100
32.42783465Y2008 =
=−
+=
980664876560*10
3*
100
32.42876560Y2011 =
+=
1014189973586*10
1*
100
32.42973586Y2012 =
+=
13014741006868*10
9*
100
32.421006868Y2021 =
+=
13763411292080*10
2*
100
32.421292080Y2023 =
+=
15197631366407*10
4*
100
32.421366407Y2027 =
+=
19099461508794*10
11*
100
32.421508794Y2038 =
+=
20675441896161*10
4*
100
32.421896161Y2042 =
+=
Table A-2.9: Summary of the Consultant’s Population Projection
Year Incremental
Increase
Method
Geometric
Increase
Method
Arithmetic
Increase
Method
Decreasing Rate
of Growth
Method
Final Population
(As per CPHEEO Manual)
2001 6,70,042 6,70,042 6,70,042 6,70,042
2005 7,25,018 7,79,181 7,10,474 7,83465
2008 7,66,250 8,72,551 7,40,798 8,82932
2011 8,07,482 9,77,110 7,71,123 9,80664
2012 8,21,226 10,14,676 7,81,231 10,14,189
Projected
population @
3.48% per annum
taking base year
2021 by Geometric
Increase Method
2021 9,44,922 14,24,900 8,72,203 13,01,474 14,24,900
2023 9,72,410 15,36,571 8,92,419 13,76,341 15,25,799
2027 10,27,386 17,86,855 9,32,852 15,19,763 17,4,9536
2038 11,78,570 27,05,917 10,44,040 19,09,946 25,48,846
2042 12,33,545 31,46,669 10,84,473 20,67,544 28,24,313
ANNEXURES
Annexure - 2
As per CDP Raipur City, the population projection for the year 2021 is 14,98,216 souls (Table A-2.3) which is
very near to the population forecast 14,24,900 souls (Table A-2.9) for the same year as per geometrical
increase method.
The CDP also mentioned average annual growth rate of the city after the year 2011 will be 3.48% (CDP,
Table 2.1, Page-15).
The PDR-AWS mention that the population growth rate will be @3.48% per annum beyond the year 2021
and hence the population projection has been made for the ultimate stage year 2042 taking the growth rate
of 3.48% per annum i.e. 28,24,313 souls (Table A-2.9).
ANNEXURES
Annexure - 2
E. Comparison between CDP, DPR and Consultant’s Projection
The above section deals with the projection of population for the Raipur City with different methods. The population that has been taken for projection pertains to population of
Municipal Corporation area as per census 2001. The projected population is compared and summarized in Table A-2.10.
Table A-2.10: Summary of the Population Projection
Year Incremental
Increase
Method
Geometric
Increase
Method
Arithmetic
Increase
Method
Decreasing Rate
of Growth
Method
Final
Population
Incremental
Increase
Method
Geometric
Increase Method
Arithmetic
Increase
Method
Average
Growth
Method
Average
Annual
Growth rate
(As per CPHEEO Manual) (As per DPR-RAWS Scheme, Raipur) (As per CDP,
Raipur)
2001 6,70,042 6,70,042 6,70,042 6,70,042 6,70,042 6,70,042 6,70,042 6,70,042 6,70,042
2005 7,25,018 7,79,181 7,10,474 7,83465 7,35,925 7,78,907 7,10,474 7,57,735 8,66,545
2008 7,66,250 8,72,551 7,40,798 8,82932 7,94,882 (8,72,014)* 7,40,798 8,25,819 --
2011 8,07,482 9,77,110 7,71,123 9,80664 -- -- -- -- 10,64,045
2012 8,21,226 10,14,676 7,81,231 10,14,189
Projected
population @
3.48% per
annum taking
base year
2021 by
Geometric
Increase
Method
-- -- -- -- --
2021 9,44,922 14,24,900 8,72,203 13,01,474 14,24,900 -- 14,22,398 -- -- --
2023 9,72,410 15,36,571 8,92,419 13,76,341 15,25,799 12,12,379 (15,33,603)** 8,92,418 13,17,915 --
2027 10,27,386 17,86,855 9,32,852 15,19,763 17,49,536 -- -- -- -- --
2038 11,78,570 27,05,917 10,44,040 19,09,946 25,48,846 18,34,396 26,97,133
(21,35,960)***
10,44,038 20,90,239 --
2042 12,33,545 31,46,669 10,84,473 20,67,544 28,24,313 -- (24,49,169)**** -- -- --
*Population in base year 2008 (beginning of design period, Table 1.5); **Projected population after 15th
year 2023 (intermediate stage of design period); ***Projected population after 30th
year 2038
(ultimate stage of design period) @ 3.48% per annum growth rate; ****Projected population for year 2042 @ 3.48% from the base population of 21,35,960 souls for year 2038.
ANNEXURES
Annexure - 2
F. Conclusion & Recommendations
1. Taking the population (15,33,603 souls, Table A-2.5) of year 2023 into consideration for estimation of
population by the year 2038, the population would be 25,61,883 souls which is 4,25,923 souls higher
than the projected population in DPR as 21,35,960 souls by the 2038.
2. Since the project is envisaged for commissioning by year 2012, the beginning population for project is
considered for year 2012. Therefore, the 30 year design period as per CPHEEO is taken as year 2042.
3. Year 2027 is taken as intermediate design period (i.e. 15 years from year 2012).
4. The DPE-AWS is prepared for ultimate population of 21,35,960 souls in year 2038 mentioning @ 3.48%
per annum growth rate after year 2023. However, the population projected @ 3.48% per annum in
consideration with base year 2008 for design of water supply system.
5. It is prudent to assume the growth rate of 3.48% for the extended period beyond year 2038 and upto
year 2042 which is ultimate year for sewage project.
6. The projected population beyond year 2021 is based on uniform growth rate of 3.48% per annum,
which is in line with water supply DPR-AWS.
7. The intermediate stage (year 2027) and ultimate stage (year 2042) population for the project is
suggested as 17,49,536 souls and 24,49,169 souls, respectively.
8. The difference in population (24,49,169 – 21,35,960 = 3,13,209 souls, Table A-2.10) projected for
extended period upto ultimate year 2042 from the year 2038 from DPR-AWP is 3,13,209 souls taking @
3.48% per annum growth rate.
9. In view of above analysis and computations, RMC may communicate accordingly the population to be
adopted for sewage project design.
G. Distribution of Population
The final selected projected design population will be suitably distributed into various municipal wards
on the basis of area and density, considering the growth potential of wards.
H. Rate of Water Supply
As per the recommendations given in CPHEEO manual, per capita water supply per day in Raipur town
has been considered as 135 LPCD for domestic and non-domestic needs plus 15% UFW considerations.
The same value has been considered in DPR-AWS. The details of total water demand as per DPR-AWS
are given in Table A-2.11 and total water demand excluding 15% UFW are given in Table A-2.12.
The remaining population beyond year 2038 upto year 2042 for this project is projected as 3,13,209
souls. This population has been accounted for additional water requirement beyond the water required
by the year 2038 in DPR-AWS.
Table A-2.11: Total Water Demand Computation as per DPR-AWS
Water Demand, MLD Sr.
No.
Need of water
2008 2023 2038
1 Population 8,72,014 15,33,603 21,35,960
2 Domestic & Non-domestic purpose 135.38 238.10 331.60
3 Institutional purpose 6.60 6.70 6.70
4 Industrial purpose 25.00 27.00 37.00
5 Fire fighting 2.95 4.35 4.62
Water demand 169.93 276.15 379.92
Say, Total water demand 170.00 277.00 380.00
Source: DPR-AWS, Raipur City, Page 40.
ANNEXURES
Annexure - 2
Table A-2.12: Total Water Demand Computation as per DPR Excluding 15% UFW
Water Demand, MLD Sr.
No.
Need of water
2008 2023 2038
1 Population 8,72,014 15,33,603 21,35,960
2 Domestic & Non-domestic purpose 117.72 207.04 288.35
3 Institutional purpose 6.60 6.70 6.70
4 Industrial purpose 25.00 27.00 37.00
5 Fire fighting 2.95 4.35 4.62
Water demand 152.27 245.09 336.67
Say, Total water demand 153.00 246.00 337.00
The values mentioned in Table A-2.12 are net water demand at consumer end which is eventually
contributing to sewage generation.
I. Sewage Generation
The quantity of sewage generation for intermediate design stage on the basis of projected population
for year 2027 is given in Table A-2.13.
Table A-2.13: Total Sewage Generation at Intermediate Stage
Year Description Water Demand,
MLD
Rate of Sewage
Generation, %
Sewage Quantity,
MLD
Domestic & Non-
domestic purpose
(population = 17,49,536)
236.18 80 188.94
Institutional purpose 6.70 70 4.69
2027
Industrial purpose 27.00 70 18.90
269.88 - 212.53
Say 213.00 MLD
Sewage Generation for Intermediate Design Stage = 213.00 MLD.
The quantity of sewage generation for ultimate design stage on the basis of net water demand (Table A-
2.12) is given in Table A-2.14.
Table A-2.14: Total Sewage Generation at Ultimate Stage
Sr.
No.
Description Sewage Generation by
year 2038, MLD
1 Population 21,35,960
2 Water demand 288.35
2 Domestic & Non-domestic purpose @ 80% of water
supply
230.68
3 Institutional purpose @ 70% of water supply 4.69
4 Industrial purpose @ 70% of water supply 25.90
Sewage generation 261.27
Say, Total Sewage Generation 262.00
Contribution of sewage beyond year 2038 and upto year 2042 (ultimate design stage) by the population
of 3,13,209 souls = 313209 souls * 135 LPCD * 80% = 33.83 MLD, Say 34.00 MLD.
Sewage Generation for Ultimate Design Stage = 262.00 + 34.00 = 296.00 MLD.
*****
ANNEXURES
Annexure - 3
Annexure -3 Influent Sewage Characteristics
STP pH TSS, mg/l COD, mg/l BOD, mg/l
Okhla 7.3 498 560 282
7.4 291 486 207
7.4 647 551 222
7.3 480 515 249
7.3 480 515 249
Narela 7.4 426 447 100
Yamuna Vihar 7.1 391 505 174
7.2 405 538 199
Timarpur 6.7 412 272 106
Najafgarh 7.4 165 205 54
Nilothi 7.7 432 328 90
Dr. Sen N. H. 7.5 370 585 236
Kondli 7.3 363 507 241
7.3 604 588 261
7.3 519 615 237
Rithala 7.2 330 399 205
7.2 330 399 205 Source: CPCB, Sewage Pollution, Parivesh News letter, February 2005.
ANNEXURES
Annexure - 3
Annexure -3 Sewage Characteristics by Regional Office
C.G. Environment Conservation Board
New H.I.G. 9, 10, 11 Tatibandh, Raipur (C.G.)
S.
No. Characteristies Unit Result I Result II Result III Result IV Result V Result VI Result VII Result VIII Result IX Result X
1 Appearance -- Blackish
Turbid
Slight
Turbid
Blackish
Turbid
Slight
Turbid
Blackish
Turbid
Blackish
Turbid
Blackish
Turbid
Blackish
Turbid
Blackish
Turbid
Blackish
Turbid
2 Odour -- Unpleasant Unpleasant Unpleasant Unpleasant Unpleasant Unpleasant Unpleasant Unpleasant Unpleasant Unpleasant
3 pH pH Unit 7.78 7.36 7.50 7.52 7.63 7.09 7.50 7.65 7.59 7.47
4 Total Solids Mg/Liter 1868.6 545.2 606.6 423.8 451.3 528.1 583.3 699.7 756.0 603.2
5 Total Dissolved Solids " 1292.6 478.0 425.0 410.0 336.0 436.1 475.0 605.0 654.0 441.0
6 Suspended Solids " 576.0 67.2 181.6 13.8 115.3 92.1 108.3 91.7 102.0 162.2
7 Dissolved Oxygen " 2.8 Nil Nill Nill 4.4 Nill Nill 2.0 Nill 0.3
8 B.O.D. (3-days at 27°C) " 230.0 136.0 115.0 155.0 165.0 188.0 145.0 80.0 190.0 205.0
9 C.O.D. " 422.4 268.8 230.5 307.2 345.6 384.0 268.8 153.6 384.0 422.1
10 TKN " 7.0 4.2 3.6 4.2 4.5 5.6 6.4 6.2 5.9 5.6
11 Sulphate (as SO4) " 34.1 18.9 16.5 9.8 13.1 17.4 9.6 15.4 15.5 14.1
12 Phosphate (as PO4) " 3.0 2.2 2.6 2.8 1.8 2.2 2.7 2.5 2.3 2.0
13 Chloride (as CI) " 148.8 127.1 98.0 121.6 72.6 90.8 99.8 99.8 163.4 85.3
14 Oil & Grease " 16.0 11.0 13.0 14.0 15.0 19.0 12.0 10.0 19.0 14.0
15 Total Coliform (M.F. Technique) MPN/100
ml 18700.0 6000.0 12000.0 16000.0 7600.0 2250.0 16200.0 8000.0 10000.0 14000.0
S. No. Description of Sampling Location
1 Nala Water, Ward No. 14 Ishwari Sharma Shukla, Raipur
2 Nala Water, Ward No. 4 Near Rly Crossing Khamtarai
3 Nala Water, Ward No. 8 Netaji Kanhaiyalal Banjari, Raipur
4 Nala Water, Ward No. 10 Housing Board Colony Pahadi Chowk, Gadhiyari, Raipur
5 Nala Water, Ward No. 62 Near Mahamaya Mandir Mahamai Para, Raipur
6 Nala Water, Ward No. 20 Near Simran Heritage Rly Station Road, Raipur
7 Nala Water, Ward No. 34, Before Avanti Bai Chowk Raipur
8 Nala Water, Ward No. 32 Telibandha Rly Crossing Left side, Raipur
9 Nala Water, Ward No. 27 Mova Rly Crossing, Raipur
10 Nala Water, Ward No. 46 Dr. Rajendra Pradad Ward Amlidi- Raipur
ANNEXURES
Annexure - 4
Annexure - 4 Type of Growth System
Process Common Name Use AEROBIC PROCESS
Activated Sludge Process (ASP)
Extended Aeration
Oxidation Ditch
Suspended growth
Aerated Lagoon
BOD removal, nitrification
Trickling Filter (TF) Attached growth
Rotating Biological Contactors (RBC)
BOD removal, nitrification
Activated bio-filter process
Trickling filter solids contact
Bio-filter activated sludge
Combined suspended and
attached growth
Series trickling filter activated
sludge
BOD removal, nitrification
ANOXIC PROCESS
Suspended growth Suspended growth denitrification Denitrification
Attached growth Fixed-film denitrification Denitrification
ANAEROBIC PROCESS
Anaerobic digestion Stabilization, BOD removal
Standard rate, single-stage Stabilization, BOD removal
High rate, single-stage, Two-stage Stabilization, BOD removal
Suspended growth
Upflow anaerobic sludge blanket
(UASB)
BOD removal
Anaerobic filter process BOD removal, waste stabilization Attached growth
Expanded bed BOD removal, waste stabilization
COMBINED AEROBIC, ANOXIC AND ANAEROBIC PROCESSES
Single or multi-stage processes Suspended growth
Biological Nutrient Removal (BNR)
BOD removal, nitrification,
denitrification, and phosphorus removal
Combined suspended
and attached growth
Single or multi-stage processes BOD removal, nitrification,
denitrification, and phosphorus removal
POND PROCESSES
Aerobic ponds BOD removal
Maturation (tertiary) ponds BOD removal
Facultative ponds BOD removal
Anaerobic ponds BOD removal
ANNEXURES
Annexure - 4
Annexure - 4
Details of STP Under Various Schemes SEWAGE TREATMENT PLANT CAPACITY UNDER YAMUNA ACTION PLAN
S.No Town No. of STPs Capacity (MLD) Type Status of the STP
I HARYANA
1 Yamunanagar STP-I 10.00 UASB Functional
STP-II 25.00 UASB Functional
2 Karnal STP-I 40.00 UASB Functional
STP-II 8.00 OP Functional
Panipat STP-I 10.00 UASB Functional
STP-II 35.00 UASB Functional
4 Sonepat STP-I 30.00 UASB Functional
5 Gurgaon STP-I 30.00 UASB Functional
6 Faridabad STP-I 20.00 UASB Functional
STP-II 45.00 UASB Functional
STP-III 50.00 UASB Functional
7 Chhchhrauli STP 1.00 OP Under construction
8 Gharaunda STP 3.00 OP Under construction
9 Gohana STP 3.50 OP Under construction
10 Indri STP 1.50 OP Under construction
11 Palwaal STP 9.00 OP Under construction
12 Radaur STP 1.00 OP Under construction
Sub Total 17 322.00
II DELHI
13 Delhi STP-I 10.00 ASP Functional
STP-II 10.00 ASP Functional
Sub Total 2 20.00
III UTTAR PRADESH
14 Saharanpur STP 38.00 UASB Functional
15 Muzaffar Nagar STP 32.50 OP Functional
16 Ghaziabad STP-I 70.00 UASB Functional
3.00 KT Functional
STP-II 56.00 UASB Functional
17 Noida STP-I 34.00 UASB Functional
STP-II 27.00 UASB Functional
STP-III 9.00 OP Functional
18 Vrindavan STP-I 4.00 OP Functional
STP-II 0.50 OP Functional
19 Mathura STP-I 14.50 OP Functional
STP-II 12.50 OP Functional
20 Agra STP-I 78.00 UASB Functional
STP-II 10.00 OP Functional
STP-III 2.25 OP Functional
21 Etawah STP 10.00 OP Functional
Sub Total 15 401.25
Total 34 743.25
BCT -Bio-Chemical Technology KT -Karnal Technology
ANNEXURES
Annexure - 4
The STPs were either renovated or constructed to treat the domestic sewage by adopting
treatment technologies such as low cost waste stabilization ponds, conventional Activated Sludge
Process (ASP) Trickling Filter (TF) and Upflow Anaerobic Sludge Blanket (UASB) treatment systems.
The details are provided below.
Treatment Systems under GAP Phase I
in Uttranchal, Uttar Pradesh, Bihar and West Bengal
Sr.
No.
Treatment
System
Total
No.
Total Capacity
of STP (MLD)
Names of towns
1 Oxidation
Pond
11 134.04 UTTARANCHAL (1) Lakkar Ghat- Rishikesh
UTTAR PRADESH(1)Farukhabad,
BIHAR (2)Chapra, Patna Eastern Zone
WEST BENGAL (9)South,Suburban, Bhatpara, Titagarh
(2), Panihati, Bally, Kalyani, Bahrampore, Nabadwip
2 Activated
Sludge
Process
12 507.5 UTTARANCHAL (1) Kankhal-Hardwar
UTTAR PRADESH(5) Kanpur,Alllahabad, Varanasi-BHU,
Varanasi Dinapur & Varanasi SPT-DLW BIHAR (2) Patna
- Saidpur,Patna, Beur WEST BENGAL (4) Garden Reach,
Cossipore-Chitpur (Bangur), BhatparaB, Titagarh
3 Trickling
Filter
5 134.26 West Bengal (5) Baranagar-Kamarhatti, Kalyani,
Serampore, Howrah, Chandannagore
4 RBRC 1 0.33 UTTARANCHAL (1)Swargashram- Rishikesh
5 UASB 3 55 UTTAR PRADESH (3)Kanpur(2),Mirzapur
6 Aerated
Lagoon
3 49.5 BIHAR(3) Patna-Sourthern Zone, Munger,Bhagalpur
Note:- RBRC : Rotating Biological Rope Contractor
OP : Oxidation pond
ASP : Activated sludge process
UASB : Up flow anaerobic sludge blanket
AL : Aerated lagoon
TF : Trickling Filter
Out of 35 STPs planned under GAP Phase I (3 STPs in Uttaranchal, 10 STPs in UP, 7 STPs in Bihar,
and 15 STPs in West Bengal), 32 STPs are commissioned and 29 STPs were found functioning.
ANNEXURES
Annexure - 5
ANNEXURE - 5 General Standards* for Discharge of Environmental Pollutants
Part - A: Effluents
Sr.
No.
Parameter Inland surface
water
Public sewers Land for
irrigation
Marine/coastal
areas
. . (a) (b) (c) (d)
1 Colour and Odour ++ ++ ++
2 Suspended solids
mg/l, max.
100 600 200 (a) For process
wastewater
(b) For cooling
water effluent 10
per cent above
total suspended
matter of influent.
3 pH value 5.5 to 9.0 5.5 to 9.0 5.5 to 9.0 5.5 to 9.0
4 Temperature shall not exceed
5oC above the
receiving water
temperature
shall not exceed
5oCabove the
receiving water
temperature
5 Oil and grease,
mg/l max,
10 20 10 20
6 Total residual
chlorine, mg/l
max
1.0 - - 1.0
7 Ammonical
nitrogen (as
N),mg/l, max.
50 50 - 50
8 Total kjeldahl
nitrogen (as
N);mg/l, max.
mg/l, max.
100 - - 100
9 Free ammonia (as
NH3), mg/l, max.
5.0 - - 5.0
10 Biochemical
oxygen demand
(3 days at 27oC),
mg/l, max.
30 350 100 100
11 Chemical oxygen
demand, mg/l,
max.
250 - - 250
12 Bio-assay test 90% survival of
fish after 96
hours in 100%
effluent
90% survival of
fish after 96
hours in 100%
effluent
90% survival of
fish after 96
hours in 100%
effluent
90% survival of
fish after 96 hours
in 100% effluent
* These standards shall be applicable for industries, operations or processes other than those industries,
operations or process for which standards have been specified in Schedule of the Environment Protection
Rules, 1989.
++ All efforts should be made to remove colour and unpleasant odour as far as practicable
ANNEXURES
Annexure - 6
ANNEXURE - 6