Sewage Storm Water Work - Raipur

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



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



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



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



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


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





(refer Table below).

Area, Population and Sewage Generation on Zone - III


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.



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



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.



Total Cost For STPs (Intermediate Stage)


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



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.



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

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Project Report - Sewerage Chapter 1: Introduction


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.



Figure 1: location MAP



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.



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



(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:



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.



Details Of Civil Works (Khamtarai Pumping Station)


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



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)


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)


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



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)


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



Details Of Pumps and Machinery (Tikrapara Pumping Station)


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)


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)


1 No. of Pumping Sets Installed 3 Nos

2 Discharge of 2 Nos. of Pumping Set 9 MLD. Each



Details Of Pumps and Machinery (Khokhopara Pumping Station)


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)


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



Details of Pump and Machinery (Daldal Seoni Main Pumping Station)


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


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



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


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



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.



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.



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.



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



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.



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

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Project Report - Sewerage Chapter 2: Planning of Sewerage System


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;



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.



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.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Project Report - Sewerage Chapter 3: Population Projection


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



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



• 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.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Project Report - Sewerage Chapter 4: Sewage Generation


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





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





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.



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

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Project Report - Sewerage Chapter 5: Design Considerations


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



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



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.



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.



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.



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



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



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

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 6: Design Criteria


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



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



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.



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.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 7: Design of Sewers


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



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.



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



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


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



Table - 7.1: Area, Population and Sewage Generation on Zone - I


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



(refer Table 7.2).

Table - 7.2: Area, Population and Sewage Generation on Zone - II


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



Table - 7.2: Area, Population and Sewage Generation on Zone - II


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



(refer Table 7.3).

Table - 7.3: Area, Population and Sewage Generation on Zone - III


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



Table - 7.3: Area, Population and Sewage Generation on Zone - III


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



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.



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



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



Table 7.5: Summary of Design Length



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

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 8: Design of Sewage Pumping Station


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



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



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.



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

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 9: Design of Sewage Treatment Plant


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.



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



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



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



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



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



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.



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.



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



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



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



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



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%.



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.



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



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


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



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)


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)


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.



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).



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



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.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 10: Environmental Impacts


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.



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



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

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 11: Operation and Maintenance


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

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 11: Operation and Maintenance


� 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.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 12 : Project Management


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



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



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.



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.



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



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.



• 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.



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.



(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.



(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.



(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.



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.



� 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.



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



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

***



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:



RECEIVING INSPECTION CHECKLIST

Project 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 :



WORKS INSPECTION CHECKLIST

Structural Work (RCC / Concrete) Inspection

Project 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:



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 :

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 13 : Cost Estimates


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.



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



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



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



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.



The above costs are exclusive of 6% departmental charges and contingencies. The cash flow

statement is placed at Annexure-7.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 14 : Financial Analysis


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

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 14 : Financial Analysis


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.

***

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 15 : Conclusions and Recommendations


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

Project Management Consultancy Services for Sewerage, Storm, Surface Water Drains and Lake Protection Works For Raipur City Detailed Design Report - Sewerage Chapter 15 : Conclusions and Recommendations


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


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


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,



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,



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.


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)


Activated bio-filter process

Trickling filter solids contact

Bio-filter activated sludge

Combined suspended and

attached growth

Series trickling filter activated

sludge


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


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-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


17 Noida STP-I 34.00 UASB Functional


STP-III 9.00 OP Functional

18 Vrindavan STP-I 4.00 OP Functional


19 Mathura STP-I 14.50 OP Functional


20 Agra STP-I 78.00 UASB 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