MSIG 3

First Edition

Ministry of Energy, Water and Communication Malaysia

Published by : Suruhanjaya Perkhidmatan Air Negara (SPAN)

Volume IIISewer Networks

and Pump Stations

Foreword by theCEO of SPAN

unicipal wastewater treatment technology in Malaysia has evolved through several eras. In thepast, only basic facilities were used, e.g. overhang latrines, pit privy, bucket systems and pourflush systems. Some improvement were observed when more modern system like septic tank andImhoff tank systems were introduced into the country some 40 years ago. The municipal

wastewater treatment in Malaysia sees a significant improvement in the last three decades since the introductionof new technologies in the form of oxidation ponds, aerated lagoons, activated sludge system, package systemsand a variety of mechanical plants into the country. However, sewage still remains as one of the major pollutantsof our inland waterways. In the 1900s, the emergent of new treatment technologies were mainly driven by thebasic need to treat the sewage so as to control waterborne diseases. Today, the environmental regulations arebecoming stringent with the increasing awareness toward sustainable environmental management. Allowableeffluent discharge limits are becoming lower globally. Public are also more educated and more alert on the needsto preserve the environment. Hence the evolution of municipal wastewater treatment technologies now are evenmore revolutionary and more rapid in order to meet the stricter regulators’ requirements and to compete in theincreasing competitive market.

While the nation moves towards achieving the status of a developed country, sustainability of our environment,in particularly the Malaysian rivers and streams must be strengthened. With this vision in mind, the SewerageServices Department published its first edition of the guidelines for sewerage industry titled “Design andInstallation of Sewerage Systems” in January 1995. The main purpose of these guidelines is to assist thedeveloper and his designer to plan and design systems acceptable to the regulatory authorities which, inturn speeds up the approval processes. The Guidelines has clearly guided the nation sewerage industry towardsachieving an improved sewerage system in the country. Subsequently, the Department further improvised theGuidelines in its second edition titled “Guidelines for Developers” which comprise five volumes coveringspecific topics.

As a continuation to the efforts by the Sewerage Services Department, the National Water Services Commissionundertake to revise and improvement the Guidelines for Developers. The product of the revision is “MalaysianSewerage Industry Guidelines” which also comprise five volumes. These new revisions incorporated valuableknowledge gained by various stakeholders over a decade since the implementation of the first Guidelines forDevelopers and upkeep with the aim towards sustainable environmental management.

Volume 1 - Sewerage Policy for New DevelopmentsVolume 2 - Sewerage Works ProceduresVolume 3 - Sewer Networks and Pump StationsVolume 4 - Sewage Treatment PlantsVolume 5 - Septic Tanks

Volume 3 is specifically developed to provide a clear understanding of policies of the SPAN for theprovision, refurbishment or upgrading of sewer networks and pumps stations. This volume coversplanning, design, material selection, construction, installation and sewer testing requirements. Theimplementation of these guidelines since 90’s has undoubtedly achieved some levels of consistency in thedesign and construction of sewerage network nationwide. Finished sewerage networks quality has alsobeen elevated while the operation and maintenance of the plants have improved significantly in terms ofsafety, health, operability and robustness. Whilst the adherence to these guidelines is necessary,engineering discretion is also required, especially for large sewers and pumping station with specialsituations. It is hoped that the publication of the third edition of this Volume further improve the municipalwastewater treatment facilities in this country.

Dato’ Teo Yen HuaChief Executive OfficerSPAN

M

© Copyright National Water Services Commission, Ministry of Energy, Water andCommunications, 2008

All rights reserved.

This publication is protected by copyright.

No part of this publication may be reproduced, distributed, transmitted, stored in a retrievalsystem, or reduced to any electronic medium without the written authority of the Commissioner,National Water Services Commission, Ministry of Energy, Water and Communications,.

National Water Services Commission and Registered Certifying Agencies employees arepermitted to copy and use the information in this publication, for internal purposes only.

Changes may be made periodically to the information herein.

TABLE OF CONTENTS PAGE

Section 1 Introduction1.1 Purpose of This Volume 1

1.2 Who Should Use This Volume 1

1.3 Related Reference Material 1

Section 2 Planning, Material and Design2.1 Sewers 9

2.1.1 Pipe Material Selection Factors 9

2.1.2 Pipe Materials and Fittings 10

2.1.3 Pipe Selections 11

2.1.4 Requirements and Limitations for Use of Certain PipeMaterial 11

2.1.5 Vitrified Clay Pipe 13

2.1.6 Reinforced Concrete Pipe 14

2.1.7 Ductile Iron Pipe 15

2.1.8 Steel Pipe 15

2.1.9 Solid Wall PE Pipe 16

2.1.10 Profiled Wall PE Pipe 16

2.1.11 Glass Reinforced Plastic Pipe 17

2.1.12 Acrylonitrile Butadiene Styrene Pipe 18

2.1.13 Sewer Design - General Requirements 18

2.1.14 Flow Rate Estimations 19

2.1.15 Sewer Cleansing Velocities 20

2.1.16 Pipe Roughness 20

2.1.17 Design of Gravity Sewer 21

2.1.18 Design of Force Mains 23

2.1.19 Vacuum Sewerage System 25

2.1.20 Computerised Sewer Designs 36

2.1.21 Design of Inverted Siphon 37

2.1.22 Structural Design of Sewers 37

2.2 Manhole 40

2.2.1 General 40

2.2.2 Manhole Location 42

2.2.3 Pipe Lengths from Manhole 42

2.2.4 Structural Design Considerations for Manhole 43

2.3 Manhole Covers and Frames 44

2.3.1 General 44

2.3.2 Load Class 44

2.3.3 Material 44

2.3.4 Dimensions, Marking and Surface Finish 44

2.3.5 Seating 44

2.3.6 Casting 45

2.3.7 Protective Coating 45

2.3.8 Water-tightness 45

2.3.9 Safety Features 45

2.3.10 Product Certification 45

2.4 Design of Network Pump Stations 46

2.4.1 Specifying of Network Pump Stations 46

2.4.2 General Requirements 46

2.4.3 Buffer Requirements 47

2.4.4 Pipework Requirements 47

2.4.5 Wet-well Requirements 48

2.4.6 Dry-well Requirements 48

2.4.7 Structural Requirements 49

2.4.8 Ventilation Requirements 49

2.4.9 Odour Control 50

2.4.10 Requirements for Lighting and Electrical Fittings 50

2.4.11 Acceptable Pump System (Fixed Speed PumpsOnly) 50

2.4.12 Valve Requirements 51

2.4.13 Requirements for Level Controls 52

2.4.14 Requirements for Alarms 52

2.4.15 Requirements of Hydraulic Design and Performance52

2.4.16 Maintenance Considerations 52

2.4.17 Hazard and Operability 53

2.4.18 Other Requirements 53

2.5 Interceptors 56

2.5.1 Oil Interceptors 56

2.5.2 Grease Traps 56

2.6 Concrete and Reinforcement Requirements 56

2.6.1 Concrete 57

2.6.2 Cement 57

2.6.3 Steel Reinforcement and Falsework 57

Section 3 Construction and Installation3.1 Introduction 59

3.2 Pipes and Fittings Delivery and Handling 59

3.2.1 Pipes and Fittings Delivery 59

3.2.2 Pipe Handling at Site 60

3.2.3 Pipe Storage 61

3.2.4 Pipe Damage 62

3.3 Trench Excavation 63

3.3.1 Protection of Affected Services, Structures, Pavementsand Vegetation 63

3.3.2 Excavation Requirements 64

3.3.3 Bored Excavation 66

3.4 Pipe Laying 66

3.4.1 Pipe Bedding 66

3.4.2 Pipe and Fittings Placement 67

3.4.3 Pipe Jacking 68

3.4.4 Concrete Pipe Support 68

3.4.5 Pipe Cutting 69

3.4.6 Backfill of Trench 69

3.5 Pipe Jointing 70

3.5.1 Flexible Joints 70

3.5.2 Solvent Weld Joints 71

3.5.3 Flanged Joints 72

3.5.4 Steel Pipe Welded Joints (Field Welding) 72

3.5.5 Polyethylene Butt Welded Joints 73

3.6 Special Requirements For Sewer 73

3.6.1 Thrust Blocks for Pressure Pipelines 73

3.6.2 Pipe Restraints and Bulkheads on Steep Slopes 74

3.6.3 Pipe Embedment and Overlay 74

3.6.4 Sleeving of Ductile Iron Pipe 75

3.7 Reinstatement 75

3.8 Connections to Public Sewers 76

3.8.1 General 76

3.8.2 Junction Connections 77

3.8.3 Saddle Connections 77

3.8.4 Manhole Connections 78

Section 4 Sewer Testing4.1 General 79

4.2 Testing of Gravity Sewers 80

4.3 Testing of Forced Mains 81

4.4 Testing of Manhole and other ancillaries 81

4.5 Low Pressure Air Test 82

4.5.1 General 82

4.5.2 Procedure for Testing 82

4.5.3 Procedures for Handling Air Test Failure 83

4.6 Low Pressure Water Test 84

4.6.1 General 84

4.6.2 Procedure 84

4.6.3 Handling Water Test Failures 85

4.7 High Pressure Water Test 86

4.7.1 General 86

4.7.2 Procedure 86

4.8 High Pressure Leakage Test 87

4.8.1 General 87

4.8.2 Procedure 87

4.9 Test for Straightness, Obstruction, and Grade 88

4.10 CCTV Inspection 88

4.10.1 Objectives of CCTV Inspection 89

4.10.2 Technical Requirements and References 89

4.10.3 Equipment Specifications and Test Devices 89

4.10.4. CCTV Inspection Requirements 90

4.10.5 CCTV Inspection Implementation Procedure for NewSewer Network 91

4.10.6 Interpretation Of Results From CCTV Inspection 93

4.10.7 Follow -Up Action to Be Taken 93

4.11 Infiltration Test 95

4.11.1 General 95

4.11.2 Procedure 95

4.11.3 Handling Test Failures 95

4.12 Water-tightness Test 95

4.12.1 General 95

4.12.2 Procedures 96

LIST OF TABLES Table 2.1a Normal Pipe Roughness for Gravity Sewer 21

Table 2.1b Normal Pipe Roughness for Force Mains for All PipeMaterials 21

Table 2.2 Typical Roughness Coefficient, ks 22

Table 2.3 Typical Manning Coefficient, n 22

Table 2.4 Typical Hazen-Williams Coefficient, C 23

Table 2.5 Condition/alarm of the station equipment 36

Table 2.6 Minimum Manhole Diameters 41

Table 2.7 Final inspection and testing 46

Table 2.8 Recommended Design Parameters for Pump Stations 54

Table 4.1 Test Duration 83

Table 4.2 Defect Grades Descriptions 94

Appendix A Typical Drawings/ DiagramsFigure A1 Standard Manhole Cover 98

Figure A2 Plan View of Typical Manhole 99

Figure A3 Typical Shallow Precast Concrete Manhole

(Ground Level to Invert of Pipe 1.2m ≤ Depth < 2.5m 100

Figure A4 Typical Shallow Precast Concrete Manhole with Backdro

(Ground Level to Invert of Pipe 1.2m ≤ Depth < 2.5m) 101

Figure A5 Typical Medium Precast Concrete Manhole

(Ground Level to Invert of Pipe 2.5m ≤ Depth < 5m) 102

Figure A6 Typical Medium Precast Concrete Manhole with backdrop

(Ground Level to Invert of Pipe 2.5m ≤ Depth < 5m) 103

Figure A7 Typical Deep Precast Concrete Manhole

(Ground Level to Invert of Pipe 5m ≤ Depth ≤ 9m) 104

Figure A8 Typical Deep Precast Concrete Manhole with Backdrop

(Ground Level to Invert of Pipe 5m ≤ Depth ≤ 9m) 105

Figure A9 Typical Details of Large Diameter Manhole (LDM) Type 106

Figure A10 Typical Induct Vent Detail 107

Figure A11 Details of Household Connection to Main SewerReticulation Pipe for V.C. Pipe 108

Figure A 12 Typical Details of Concrete Thrust and Anchor Block 109

Figure A13a Typical Details of Inverted Siphons or Depressed Sewer(Sheet 1 of 2) 110

Figure A13b Typical Details of Inverted Siphons or Depressed Sewer(Sheet 2 of 2) 111

Figure A14 Typical Details of Receiving Manhole, Force Main andWashout Valve 112

Figure A15 Precast Concrete Chamber (Type A ) and Details of AirValve and Scour Valve Chamber 113

Figure A16 Standard Pipe Beddings 114

Figure A17 Vacuum sewage collection system 115

Figure A18 House connection 115

Figure A19a Example of vacuum station with housed collection vessel116

Figure A19b Example of vacuum station with housed collection vessel117

Figure A20a Collection chambers with interface valves vented throughbreather pipes 118

Figure A20b Collection chamber with interface valve activated by float118

Figure A20c Multi-valve collection chamber 119

Figure A21 Vacuum sewer profiles (not to scale) 120

Figure A22 Example of vacuum sewer profiles for uphill and downhilltransport (not to scale) 120

Figure A23 Y-branch for vacuum sewer 121

Figure A24 Method of joining crossover pipes and branch sewers tovacuum mains 121

Figure A25 Typical details of dry-well pump station 122

Figure A26 Typical detail of wet-well pump station 123

Figure A27 Buffer Zone for Pump Station with Super Structure 124

Figure A28 Buffer Zone for Pump without Super Structure 125

Figure A29 Buffer Zone for Pump without Super Structure 126

Appendix B TablesTable B1 : Classes of Rigid Pipe Required for Various Depth 127

Appendix C CCTV Format and CodesAppendix C 1 Report format for CCTV Inspection 129

Appendix C 2 Report format for CCTV Inspection 130




Appendix C 6 Module 134

Section 1

Introduction

Introduction

Sewer Networks and Pump Stations Volume 3 1

1.1 Purpose of This Volume

This volume sets out the requirements of the National Water Services Commission(SPAN) (referred to as the Commission in this document) for the design,construction and testing of sewer networks and network pump stations.

The owner must comply with the requirements set out in this volume whensubmitting an application for the approval of the Commission.

This volume generally does not cover internal plumbing systems within buildings.However, some guidelines are provided on the provision of interceptors to protectpublic sewers from the discharge of oil and grease from garage workshops, hotels,restaurants, canteens or any premises that collect such matter.

1.2 Who Should Use This Volume

This volume is primarily intended for owners, developers, consulting engineers,sewerage contractors, manufacturers, planners, and Public Authorities who have adirect interest in the planning, design and installation of sewer networks and/ornetwork pump stations.

1.3 Related Reference Material

This volume does not cover all aspects of design and construction of sewernetworks and network pump stations. Where information is not covered in thisvolume, the designer shall follow the requirements given in MS 1228.

MS 1228 shall take precedence over other foreign standards in the event whenthere are discrepancies on the requirements.

The following documents are also referred to in this volume.

a) Malaysian Standardsi. MS 28 Specification for test for water for making concrete

ii. MS 29 Specification for aggregates from natural sources forconcrete

iii. MS 144 Specification for cold reduced mild steel wire forreinforcement of concrete

iv. MS 145 Specification for steel welded fabric for the reinforcementof concrete.

v. MS 146 Specification for hot rolled steel bars for the reinforcementof concrete.

vi. MS 522 Specification for Portland cement (ordinary and rapidhardening)

vii. MS 523 Specification for concrete including ready mixed concreteviii. MS 628 Specification for unplasticised PVC (uPVC) pipes for water

supply

Introduction

2 Volume 3 Malaysian SewerageIndustry Guidelines

Part 1 : PipesPart 2 : Joints and fittings for use with unplasticised PVCpipes

ix. MS 672 Specification of rubber seals in water supply, drainage andsewerage pipelines

x MS 740 Specification for hot-dip galvanized coatings on iron andsteel articles

xi. MS 822 Specification for sawn timber foundation pilesxii. MS 881 Specification for pre-cast concrete pipes and fittings for

drainage and seweragePart 1: Specification for pipes and fittings with flexiblejoints and manholes

xiii. MS 922 Specification for concrete admixturesPart 1 : Accelerating admixtures, retarding admixtures andwater-reducing admixtures

MS 923 Specification for joints and fittings for use with uPVCpressure pipes [delete]Part 3: Mechanical joints and fittings, principally of uPVC[delete]

xiv. MS 979 Specification for unplasticizes sewerage pipes and fittings

Part 1: Pipes of diameter 100mm and 155mm

Part 2: Pipes of diameter 200mm and above

xv. MS 980 Specification for safety signs and colours : Colorimetric andphotometric properties of materials

xvi. MS 981 Specification for safety signs and colours : Colour anddesign

xvii. MS 982 Specification for fire safety signs, notices and graphic symbolxviii. MS 1037 Specification for sulphate-resisting Portland cement

xix. MS 1058 MS 1058 Specification for polyethylene (PE) pipingsystems for water supplyPart 1 : GeneralPart 2 : Pipes

xx. MS 1061 Vitrified clay pipes and fittings and pipe joints for drainsand sewers

xxi. MS 1195 Code of practice for structural use of concrete

xxii. MS 1227 Specification for Portland pulverised fuel ash cement

xxiii. MS 1228 Code of Practice for Design and Installation of SewerageSystems

xxiv. MS 1347 Cathodic Protection : Part 1 Code of practice for landapplications

xxv. MS 1292 Specification for rubber seals – water stop for sealing jointsin concrete – Specification of materials

xxvi. MS 1389 Specification for Portland blastfurnace cement

Introduction


xxvii.

MS EN45011

Specification for general criteria for certification bodiesoperating product certification.

xxviii.

MSISO/IECGuide 65

General requirements for bodies operating productcertification systems

xxix 04Z005R0 Air Quality – Determination of odour concentration bydynamic olfactometry. [ KIV. To be discussed in the MainCommittee Meeting ]

b) British Standardsi. BS 65 Specification for vitrified clay pipes, fittings and

ducts, also flexible mechanical joints for use solelywith surface water pipes and fittings

ii. BS 915 Specification for high alumina cement. Metric unit.

iii. BS 3416 Specification for bitumen-based coatings for coldapplication, suitable for use in contact with potable water

iv. BS 3692 ISO metric precision hexagon bolts, screws and nuts.Specification.

v. BS 4147 Specification for bitumen based hot applied coatingmaterials for protecting iron and steel including suitableprimers where required

vi. BS 4164 Specification for coal-tar-based hot-applied coatingmaterials for protecting iron and steel including a suitableprimer

vii. BS 4248 Specification for Supersulfated cement

viii. BS 4515 Specification for welding of steel pipelines on land andoffshore.

ix. BS 5153 Specification for cast iron check valves for general purposes.

x. BS 5480 Specification for Glass Reinforced Plastic (GRP) pipes,joints and fittings for use for water supply or sewerage

xi. BS 5911 Part 1 : Precast concrete pipes, fittings and ancillaryproducts. Specification for unreinforced and reinforcedconcrete pipes (including jacking pipes) and fittings withflexible joints (complementary to BS EN 1916)

xii. BS 5975 Code of practice for falsework.

xiii. BS 6076 Specification for polymeric film for use as a protectivsleeving for buried iron pipes and fittings (for site and factoryapplication)

xiv. BS 6105 Specification for corrosion resistant stainless steel fasteners.[delete]

xv. BS 7123 Specification for metal arc welding of steel for concretereinforcement.

BS 7874 Method of test for microbiological deterioration ofelastomeric seals for joints in pipework and pipelines.

BS 8005 Sewerage [delete]

Introduction


xvi. BS 8007 Code of practice for design of concrete structures for retainingaqueous liquids

xvii. BS 8010-2.1

Code of practice for pipelines. Pipelines on land : design,construction and installation. Ductile iron

xviii. BS 8666 Specification for scheduling, dimensioning, bending andcutting of steel reinforcement for concrete.

xix. BS EN 124 Gully tops and manhole tops for vehicular and pedestrianareas. Design requirements, type testing, marking, qualitycontrol

BS EN 295 Specification for vitrified clay pipes and fittings withflexible mechanical joints [delete]Part 7: Requirements for vitrified clay pipes and joints forpipe jacking [delete]

xx. BS EN295-1

Vitrified clay pipes and fittings and pipe joints for drainsand sewers. Requirements

xxi. BS EN295-7

Vitrified clay pipes and fittings and pipe joints for drainsand sewers. Requirements for vitrified clay pipes and jointsfor pipe jacking

xxii. BS EN 545 Ductile iron pipes fittings and accessories and their joint forwater pipelines – requirements and test methods

xxiii. BS EN 598 Ductile iron pipes fittings and accessories and their joint forsewerage applications – requirements and test methods.

xxiv. BS EN 681 Elastomeric seals. Materials requirement for pipe joint sealsused in water and drainage applications.

xxv. BS EN 682 Elastomeric seals. Materials requirement for pipe joint sealsused in pipes and fittings carrying gas hydrocarbons fluids.

xxvi. BS EN 752 Drain and sewer systems outside buildings

xxvii. BS EN1091

Vacuum sewerage systems outside buildings

xxviii. BS EN1561

Specification for flake graphite cast iron

xxix. BS EN1563

Specification for spheroidal graphite or nodular graphite castiron

xxx. BS EN1982

Copper and copper alloys. Ingots and castings.

xxxi. BS EN10025

Hot rolled products of non-alloy structural steels.

xxxii BS EN10220

Seamless and welded steel tubes. Dimensions and massesper unit length.

xxxiii. BS EN10224

Non-alloy steel tubes and fittings for the conveyance ofaqueous liquids including water for human consumption.Technical delivery conditions.

xxxiv. BS EN10277

Bright steel products. Technical delivery conditions.Part 1 : GeneralPart 2 : Steels for general engineering purposes

Introduction


Part 3 : Free cutting steelsPart 4 : Case-hardening steelsPart 5 : Steels for quenching and tempering

xxxv BS EN10278

Dimensions and tolerances of bright steel products.

xxxvi BS EN13725

Air quality – Determination of odour concentration bydynamic olfactometry.

xxxvii BS EN ISO3766

Construction drawings. Simplified representation of concretereinforcement.

xxxviii BS EN ISO3506

Mechanical properties of corrosion-resistant stainless-steelfastenersPart 1 : Bolts, screws and studs.Part 2 : Nuts.

c) Australian / New Zealand and Australian Standardsi. AS/NZS

1260PVC-u pipes and fittings for drain, waste and ventapplication (refer to uPVC profiled wall pipe only)

ii. AS/NZS1477

PVC pipes and fittings for pressure applications

iii. AS/NZS2566

Buried flexible pipelinesPart 1 : Structural design

iv. AS/NZS3518

Acrylonitrile Butadiene Styrene (ABS) compounds, pipesand fittings for pressure applications.

v. AS/NZS3582

Supplementary cementitious materials for use with portlandand blended cementPart 3 : Amorphous silica.

vi. AS/NZS4323

Stationay source emissionsPart 3 : Determination of odour concentration by dynamicolfactometry.

vii. AS 3725 Loads on buried concrete pipes

viii. AS 3750.2 Paint for steel structure – Ultra high-build piant.

AS3750.12

Paint for steel structure – Alkyd/micaceous iron oxide.

ix. AS 3751 Underground mining – Slope haulage – coumplings,drawbars and safety chains.

x AS 3996 Metal access covers, road grates and frames

xi AS 4060 Loads on buried vitrified clay pipes

d) German Standardsi. DIN

16961Thermoplastic pipes and fittings with profiled outer andsmooth inner surfacesPart 1: DimensionsPart 2: Technical delivery conditions

Introduction


e) International Standardsi. ISO 1083 Spheroidal graphite cast irons - Classification

ii. ISO 3506 Mechanical properties of corrosion-resistant stainless-steelfasteners

iii. ISO TR10465

Underground installation of flexible glass-reinforcedthermosetting resin (GRP) pipesPart 1: Installation proceduresPart 3 : Installation parameters and application limits

f) Water Industry Specifications (U.K)i. WIS 04-32-

15Specification for PE 80 and PE 100 spigot fittings and drawnbends for nominal sizes up to and including 1000

ii. WIS 04-24-01

Specification for mechanical fittings and joints forpolyethylene pipes for nominal sizes 90 to 1000

iii. WIS 04-32-14

Specification for PE 80 and PE 100 electrofusion fittingsfor nominal sizes up to and including 630

g) American Society for Testing and Materiali. ASTM D

3262Specifications for “Fiberglass” Glass-Fibre-ReinforcedThermosetting- Resin Sewer Pipe

ii. ASTM D2321

Practice for Underground Installation of Flexible ThermoPlastic Sewer Pipe

iii. ASTM F 894 Specification for Polyethylene (PE) Large Diameter ProfileWall Sewer and Drain Pipe

iv. ASTM D3350

Standard Specification for Polyethylene Plastics Pipe andFitting Materials

v. ASTM D3212

Standard Specification for Joints for Drain and SewerPlastic Pipes Using Flexible Elastomeric Seals

h) Other Reference Materialsi. Simplified Tables of External Loads on Buried Pipelines - UK Transport

Research Laboratory

The Commission will, from time to time, specify additional standards to be used inthe design and construction of sewerage works. These standards shall be referredto as appropriate for the design and construction of sewer networks and networkpump stations. All standards used in the design and construction of sewerage works shall be thelatest or the most updated. When any one of the above mentioned standards iswithdrawn or superseded, the latest or updated standards shall be referred to asappropriate. This shall be the same for any applicable act, guideline, by-law, etc.related to sewerage works endorsed by the government.

Introduction


Other Guidelines in This Set The Malaysian Sewerage Industry Guidelines comprise of 5 volumes: ♦ Volume I Sewerage Policy for New Development♦ Volume II Sewerage Works Procedures♦ Volume III Sewer Networks and Pump Stations♦ Volume IV Sewage Treatment Plants♦ Volume V Septic Tanks

Introduction

8 (this page is intended to be blank) Volume 3 Malaysian SewerageIndustry Guidelines

Section 2

Planning, Material and Design



2.1 Sewers

2.1.1 Pipe Material Selection Factors

The following considerations are the important factors to be considered beforeselecting or approving any pipe material and pipeline system for sewer networks.

a) Resistance to acidic condition of which is prevalent in sewer networks intropical climates

b) Resistance to sulphate attack from aggressive soils and groundwater

c) Resistance to corrosion in contaminated soils

d) Resistance to severe abrasion from sewage flow and usual cleaningmethods

e) Resistance of the joint to groundwater entry (infiltration) and sewageescape (exfiltration)

f) Resistance of the joint material to corrosion and microbiologicaldegradation

g) Structural damages and other damages that may occur in handling

h) Handling, laying and jointing care and difficulties

i) Methods of pipe embedment to ensure structural performance

j) Maintenance of structural strength and performance in service

k) Methods of maintenance and repair

l) Cost of supply, transportation and installation

m) Range and suitability of fittings where considered for smaller diametersewers

n) Previous local experience

o) Local availability

p) Pipe pressure ratings

q) The design life of a pipe shall be at least 50 years.

r) All bolts and nuts shall be stainless steel (SS) 304.

s) Where necessary, special tools and trained personal shall be made availableduring handling and installation of pipes.

Additionally, the following factors should be considered before selecting orapproving any pipe manufacturer and supplier.

a) Compliance of products to standards

b) Compliance to additional material and product requirements specified bythe Commission

c) Quality control and assurance practised by the manufacturer and supplier toensure good pipe product quality from manufacturing to delivery



2.1.2 Pipe Materials and Fittings

There is an extensive range of pipe materials available in Malaysia for use forgravity, pressure and vacuum sewers. The materials and the standards which thepipes are required to conform to are as follows:

a) Vitrified clay (VC)i) MS 672ii) MS 1061iii) BS EN 295

b) Reinforced concrete (RC)i) MS 881ii) BS 5911iii) BS 7874iv) BS EN 681v) BS EN 682

c) Ductile iron (DI)i) BS EN 598

d) Mild Steeli) BS EN 10025i) BS EN 10224

e) Stainless Steeli) BS EN 10220

f) Polyethylene (PE) solid walli) MS 1058ii) WIS 04-32-15iii) WIS 04-32-14iv) WIS 04-24-01

g) Unplasticised polyvinyl chloride (uPVC) solid walli) MS 628 : Part 2 : Section 2ii) MS 923iii) MS 979iv) AS/NZS 1477

h) Polyethylene profiled walli) DIN 16961

i) Unplasticised polyvinyl chloride profiled walli) AS/NZS 1260

j) Glass reinforced plastic (GRP)i) BS 5480ii) AS 3571

k) Acrylonitrile butadiene styrene (ABS)i) AS/NZS 3518



Marking of all pipes shall comply with available Malaysian or British Standardswhere applicable. Additional requirements to those given in the above standardsmay be specified from time to time by the Commission.

2.1.3 Pipe Selections

Except where otherwise specifically approved by the Commission, the pipematerials to be used for a specific type of sewer are listed below:

1) Gravity sewersa) Rigid pipes b) Flexible pipesi) VCii) RC

i) GRPii) Ductile Ironiii) HDPE (Profile)

2) Force mains (Rising mains)i) Ductile Ironii) GRPiii) ABSiv) HDPE (Solid)v) Steel

3) Vacuum sewersi) ABS – for internal use

ii) HDPE (Solid) – for external use

There are specific requirements such as pipe class, joint type, linings etc. which theabove approved pipe materials must meet in order to suit the above applications.Also, there are certain limitations for use of each pipe type. These requirementsand limitations are specified in the following sections.

From time to time, the Commission will publish sewer selection guides which willprovide more detailed direction on the selection and use of sewer materials.

For other pipe materials not listed above, their use will be given considerations inspecial circumstances. However, only pipes and fittings from manufacturers andsuppliers approved by the Commission are permitted to be used for sewerageapplications.

2.1.4 Requirements and Limitations for Use of Certain Pipe Material

Unless the exemption is granted by the Commission, the following limitations orrequirements shall be followed when selecting the pipe materials:

1) Gravity Sewer

a) VC i. Only size 150 mm or above shall be used

ii. The minimum size for public sewer shall be at least 225 mm



iii. Pipe shall not be used in unstable ground

iv. Flexible joints are recommended

b) RC i. Pipe protection linings are required

ii. Only sizes 600 mm or above are allowed in compliance to thepolicy

iii. Flexible joints are recommended

c) GRP i. Pipe shall not be used in ground contaminated with high

concentration of chemicals such as solvent that can degrade thepipe

ii. Pipe shall not accept any industrial or other aggressive dischargesthat may affect the pipe integrity

iii. Pipe shall be used only when no fittings are required

iv. Only sizes 600 mm or above are allowed

d) DI i. The use is only allowed for applications needed high pipe strength

ii. Pipe protection linings and coatings are required

iii. Polyethylene sleeving is required for all buried applications

e) HDPE i. Pipe shall not be used in ground contaminated with high


ii. Pipe shall not accept any industrial or other aggressive dischargesthat may affect the pipe integrity.

iii. Only pipe with profile wall is permitted.

2) Force Mains

a) DI i. Pipe shall not be used in unstable ground


iii. Polyethylene sleeving is required for all buried applications

iv. Flexible joints are recommended



b) GRP i. Pipe shall not be used in ground contaminated with high



iii. Fittings shall be made of ductile iron

iv. Only sizes 600 mm or above are allowed

c) ABS i. Where VC or RC pipes are not suitable

ii. Only for nominated projects or as permitted by the relevantauthority

d) HDPE i. Pipe shall not be used in ground contaminated with high



e) Steel i. Pipe is allowed only for sizes 700 mm or above


2.1.5 Vitrified Clay Pipe

Vitrified clay (VC) pipe is manufactured in Malaysia in diameters of 100 mm to600 mm and lengths ranging from 0.91 m to 2.50 m. Larger diameters of VC pipeare imported. VC pipes are classified according to the pipe ring crushing strengthwhich depends on the manufacturing process and quality. VC pipes and fittings canbe produced either unglazed or glazed on the interior and/or exterior. When glazedthey need not be glazed on the jointing surfaces of the spigot and socket. VC pipeswhich are available in Malaysia are normally manufactured with spigot-socketflexible joints. Most manufacturers commonly offer a rubber ring seal. However,polyurethane seal is sometimes offered by some manufacturers.

Vitrified clay pipe that has extra chemical resistance is suitable for sewerageapplications. This type of VC pipe may be used even under very corrosive sewageenvironment. However, the potential for infiltration is great and must be minimisedby careful laying procedures on site.



Vitrified clay pipes are permitted for gravity sewers. The minimum permissiblesize for public gravity sewer shall not be less than 225mm and service connectionshall not be less than 150mm.

VC pipes and fittings shall conform to the requirements of MS1061. Pipe strengthis classified by the crushing strength (FN) value tested in accordance with BS EN295-3. The crushing strength for pipe with DN150 shall not be less than 22 kN/m.The crushing strength of the pipe with size ≥ DN 225 is classified by class number.All VC pipes and fittings shall be furnished with spigot-socket flexible joints andrubber ring seals or polyurethane seals. Glazing of VC pipes and fittings arepreferred.

2.1.6 Reinforced Concrete Pipe

Reinforced concrete (RC) pipe is manufactured in Malaysia in diameters from 150mm to 3,600 mm. The standard pipe length is 3.05 m. RC pipe is classifiedaccording to pipe crushing test load or the three-edge bearing strength which varieswith wall thickness and reinforcement.

Common reinforced concrete pipes are not resistant to acidic corrosion whichoccurs in certain septic sewage conditions. The cement used to manufactureconcrete pipe shall be factory produced by the cement manufacturer. Pipes can bemanufactured using Ordinary Portland Cement, Rapid Hardening Portland Cement,Portland Blast Furnace Cement, Portland Pulverised Fuel Ash Cement andSulphate Resisting Portland Cement. All these types of cements are corrosionresistance, except Ordinary Portland Cement and Rapid Hardening PortlandCement. To improve the corrosion resistance, high alumina cement mortar lining,PVC lining, PE lining and sacrificial lining have been used. Low heat and super-sulphated cements have also been found in some tests to improve the corrosionresistance. The inclusion of calcareous or limestone aggregate is another measurefound to improve corrosion resistance. To resist corrosion by neutral sulphatesoccurring in aggressive soils and groundwater, RC pipes are sometimesmanufactured using sulphate resistance cement and where not available, portlandpulverised fuel ash cement or portland blastfurnace cement shall be used with theapproval from relevant authority.

RC pipes are permitted for gravity sewers of diameter DN600 and larger. Pipe shallbe of Standard Strength or higher as determined from structural design. RC pipesbelow 1000mm in diameter linings shall consist of either 12mm thick high aluminacement or 38mm thick (as appropriate) sacrificial concrete lining. For RC pipesgreater than 1000mm diameters either PVC or HDPE plastic lining or 38mm thicksacrificial concrete lining shall be employed. Other linings may be used if approvalfrom the Commission is obtained. Concrete pipe junctions shall be fixed to themain pipe by the pipe manufacturer and fabricated to clay pipe dimensions.Flexible joints which utilise a rubber ring to join a rebated joint and a spigot to asocket are commonly used and are recommended. Ogee joint (fixed joint) shall beused in conjunction with concrete bedding haunching only. RC pipe when used forpipe jacking purpose, shall be comply with BS 5911. The RC pipes alsoincorporate rebated joints with joint elastomeric ring seals either integrated in theunit or supplied separately.



2.1.7 Ductile Iron Pipe

Ductile Iron (DI) pipe is manufactured in Malaysia for diameters from 80 mm to1200 mm. The imported pipe can be up to 2,000 mm. Standard lengths are 6.0 m.DI pipe is classified according to wall thickness. The pressure rating of the pipeincreases with an increase in wall thickness. Commonly used pipe strength is classK9 and shall comply with BS EN 598 for working pressure exceeding 6 bars.

DI pipe is permitted for force mains and internal pipings of pump stations. DI pipeshall be used for gravity sewers only where it is needed to take the advantages ofthe high strength of ductile iron, e.g. shallow cover sewers subjected to high liveload or sewers of above ground applications.

Pipes shall have flexible joints, i.e. spigot-socket rubber seal joints or mechanicaljoints, except for pump station pipework and valve connections where flange jointsshall be used.

Ductile iron will undergo corrosion when exposed to certain aggressivegroundwaters and conveying certain aggressive water. Therefore, the internallining protection is required to protect against corrosions. Unless otherwiseapproved by the Commission, all ductile iron pipes shall have an external coatingto be determined by a Qualified Person based on actual soil condition. For internallining of constant full flowing pipe, ordinary Portland cement shall be used, whilehigh alumina cement mortar or plastic adhesive lining is required for partly fullflowing pipes. Buried pipe shall have zinc with bitumen external coating andfittings shall have bitumen external coating. The end surfaces shall include theinternal surface of the socket and external surface of the spigot for flexibleconnection.

The finishing layer, which is normally bituminous product, shall cover the wholesurface of the applied coating and shall prevent defects such as the loss ofadhesion. In addition, the material of the finishing layer shall be compatible withthe coating.

Unless otherwise approved by the Commission, all fittings and accessories shall beprovided with external and internal epoxy coating.

Polyethylene sleeving shall be used for all the buried pipe and fittings.

2.1.8 Steel Pipe

Steel pipe is manufactured in Malaysia in a wide range of diameters up to 3000 mmand lengths up to 10 m. Pipe joints are normally welded utilising either spigot-socket ends, plain ends or a collar. Flanged and mechanical joints are alsoavailable.

Steel pipes will undergo corrosion when in contact with aggressive soil and sewageand, thus, require an internal lining and an external coating. Pipe internal liningsnormally include high alumina cement mortar, coal tar enamel, coal tar epoxy,sulphate resistant cement lining, or bitumen. Pipe external coatings often includecoal tar enamel, bitumen enamel or asphalt enamel and glass fibre.



Steel pipes are permitted only for inverted siphons (depressed sewers) and internalpump station pipework. For force main larger than 700 mm, steel pipe may beused if the approval from the Commission is obtained.

The internal and external surfaces of the pipes and fittings shall be coated withthermosetting (epoxy paint or powder or epoxy tar resin) or thermoplastic(polyethylene or polyurethane) material. The type of external protection shall bedetermined by the Qualified Person based on soil condition. Following the completionof pipe jointing, exposed steel at the joints shall be protected from corrosion bymanually applied external tape wrap and internal cement mortar lining.

A spigot and socket joint welded both externally and internally shall be used for pipejoints except for pump station pipework and valve connections where flange jointsshall be used. Mechanical joints are only permitted for cut pipe lengths, whereinternal cement mortar lining at joints is not possible and where movement of thepipeline is to be allowed for.

2.1.9 Solid Wall PE Pipe

Polyethylene (PE) pipe is resistant to sulphuric acid of concentrations that might befound in septic sewage under the worst conditions.

PE solid wall pipe is available locally in diameters up to 1,000 mm and in standardlengths of 6 m and 12 m. This pipe is normally butt fusion jointed. Pipe size of160mm or less may be flange jointed or electrofusion jointed. PE pipe is classifiedby pressure rating with static working pressures up to 1.6 MPa. High density PE(HDPE) is used for sewerage applications.

Since PE pipes are flexible, the design of the pipe/trench system is more criticalthan for rigid pipe materials. Compared to rigid pipes, the stability of flexiblepipes relies more on the side support of the earth backfill around the pipe.Consequently, in an urban environment, where the side support may be removedduring future adjacent construction of underground services, pipe failures could bemore frequent. Ground conditions which provide poor pipe side support areunsuitable for flexible PE pipe.

Solid wall HDPE pipes are suitable for buried pressure sewer and buried vacuumsewer installations. Butt fusion joints shall be used for PE pipe. uPVC fittings arenot permitted for force mains. Solid wall pipe for pressure main application shallbe of minimum PE80-PB10. The use of specific strength shall depend on the depthand nature of the soil as confirmed by the Qualified Person. Solid wall pipes forvacuum sewer shall be minimum of PE80-PN8 and at least PN10 for heavy vehicleloading.

2.1.10 Profiled Wall PE Pipe

A profiled wall pipe is a pipe with a plain inside surface and with a ribbed orcorrugated outside surface. The ribs or corrugations are normally either alignedcircumferentially or helically. These corrugated or ribbed profiles optimise the pipering stiffness to weight ratio. The pipe can be designed with double-wall profile ortriple-wall profile.



Corrugated high density PE pipe is available in Malaysia in a range of size from100mm to 3000mm nominal diameter and in standard 6m lengths. The standardjoint is a flexible spigot-socket joint with rubber seal.

Pipes from specific manufacturers in this category may be permitted by theCommission to be used for gravity sewers where special circumstances require thebenefits of such pipes.

2.1.11 Glass Reinforced Plastic Pipe

Glass reinforced plastic (GRP) pipe is currently required to be imported intoMalaysia.

There are two principal manufacturing methods for GRP pipes, centrifugal castingand filament winding. The centrifugal casting GRP pipe incorporates silica sand inthe wall structure in addition to resin and chopped strand mat glass fibres. Thesilica sand shall have a maximum particles size of 10 mm. The centrifugal castingGRP pipe shall be according to AS 3751.

The filament winding GRP pipe does not normally incorporate sand, which permitscentrifugal casting GRP pipe to have a much thicker wall, and thus much higherring stiffness than the filament winding GRP pipe. The filament winding GRP pipeuses continuous glass fibres wound helically about the pipe. The design of filamentwinding GRP pipe shall be in accordance with BS 5480.

Centrifugal casting GRP pipe is classified by internal pressure resistance forpressure applications and by pipe ring stiffness for non-pressure applications.Centrifugal casting GRP is available up to 10,000 N/m2 stiffness and up to 2.5 MPastatic working pressure. Filament winding GRP is available up to 5,000 N/m2

stiffness and up to 1.6 MPa static working pressure

Centrifugal casting GRP pipe is available in sizes from 200 mm to 2,400 mm andstandard length of 6 m. The inner surface of the pipe is usually finished with aresin rich lining which is resistance to attack by sulphuric acid that may result fromseptic sewage. Centrifugal casting GRP pipe has a rubber sealing sleeve jointwhich is supplied fitted to one end. So jointing is similar to a spigot-socket joint.These pipes can also be supplied with flange joints, sleeve-locking joints andsleeve recessed joints for special applications such as pipe jacking and pipelinetowing.

Filament winding GRP pipe is available in sizes up to 3,700 mm and standardlengths of 6m and 12m (size dependent). It also has a resin rich inner surfacealthough the thickness of this resin surface layer is often limited by themanufacturing method. Some filament winding GRP pipe manufacturersincorporate corrosion resistant glass fibres. This feature can be essential with thisGRP pipe because its resin rich surface (gelcoat) is thinner or, sometimes, removedfor fabrication purposes. Filament winding GRP pipe currently being offered canbe jointed using a sleeve and two rubber O rings. Filament winding GRP pipe doesnot have a smooth outer surface like centrifugal casting GRP pipe. Machining maybe required for the outer surface where rubber sealing rings are used. Flange jointsand mechanical couplings are also available for special applications.



GRP pipe is classified as a flexible pipe. It requires sufficient side support to retainits structural integrity in cross-section in the same way as uPVC and PE pipe. GRPpipe has lower strain limits than uPVC and PE pipes since it is made of thermosetresin, which is brittle compared to thermoplastic material. Due to its inherentstructure, GRP pipe has a much higher modulus of elasticity than uPVC and PEpipe. Thus, it may have a much thinner wall than uPVC and PE pipes to achieveequivalent ring stiffness. GRP pipe is generally available in higher stiffness than,uPVC and PE pipe.

Approval for the use of GRP pipe shall be sought from the Director General foreach project intending its use. GRP pipes are permitted for gravity and pressuresewers. For gravity sewers, GRP pipes are only permitted for sizes of 600mmnominal diameter and larger where no fittings are required. The minimum pipestiffness shall be SN 5000 with the appropriate stiffness determined in accordancewith structural design to AS 2566. For pressure sewers, fittings must only be ofductile iron meeting the coating, lining and other requirements.

2.1.12 Acrylonitrile Butadiene Styrene Pipe

Acrylonitrile butadiene styrene (ABS) pipe is a thermoplastic pipe. It ismanufactured in Malaysia in diameters up to 630 mm.

ABS pipe is classified by internal pressure resistance. It comes in various staticworking pressure ratings up to 1.5 MPa.

The most common jointing method is by solvent cementing. The cementingjointing process is more complex than the jointing process of uPVC pipe. Aspigot/socket rubber ring joint is generally not available. Because of the carerequired to make a solvent cement joint, particularly in larger diameters, thejointing of ABS pipe requires special trainings.

ABS, like uPVC and PE, is resistant to corrosion in the most corrosive sewageenvironment that could occur. ABS is used in a range of applications requiringpressure pipe. Because of its excellent resistance to abrasion and UV degradation,ABS has found use in industrial and mining applications and also in treatmentplants for sewage and water.

ABS pipes may be permitted for force mains under special circumstances whichrequire the benefits of such pipes. If used, the approval of the Commission isrequired. ABS pipes may be permitted for use in buried forced mains and buriedinterconnecting pipe-works within pump stations.

2.1.13 Sewer Design - General Requirements

The design of a sewerage system shall generally be in accordance with theprinciples set out in this guideline. Additional requirements in the MalaysianStandard MS 1228:1991 Code of Practice for Design and Installation of SewerageSystem shall also be referred to in design.

The sewerage system shall be suitably designed to carry all sewage flows includingsullage to the approved disposal point. Unauthorised connections of surface watersor excessive infiltration to the sewerage system are not permitted.



Unless otherwise agreed by the Commission, all sewers shall be sited in publicroad reserve so that access can be gained for maintenance purposes. Under specialcircumstances where the sewer cannot be sited in public road reserve thenvehicular access of at least 3 m in width and road bearing capacity of not less than5 tonne shall be provided.

A checklist for sewer reticulation design is given in the Malaysian SewerageIndustry Guidelines, Volume II.

2.1.14 Flow Rate Estimations

Few principal considerations when selecting the diameter and gradient of a sewerare:

i) to cater for peak flow

ii) to ensure that there will be a sufficient velocity during each day tosufficiently cleanse the sewer of slime and sediment

iii) to limit the velocity to avoid scouring of sewers

a) Average Flow:

The volume of sewage that needs to be treated per day is based on an assumedcontribution per person of 225 litres. Another assumption is made as to thecontribution from various types of premises where the contribution from eachpremise type is defined in terms of an equivalent population. The recommendedminimum population equivalent values are given in Table B.1.

b) Peak Flow:

The flow used to determine the diameter and gradient of the pipeline is the peakflow. Peak flow is the most severe flow that could occur on any day whenconsidering daily flow fluctuations and infiltrations. The peak flow is derived fromthe average flow by applying a peak factor for daily flow fluctuations. The peakfactor shall be estimated from the following formula:

Peak Factor = 4.7 (PE/1000)-0.11

Where PE = assumed population equivalent

c) Infiltration:

Infiltration is the amount of groundwater that enters sewers through damage in thenetwork such as cracked pipes, leaking joint seals, leaky manhole walls, etc. Thereare many variables affecting infiltration such as quality of workmanship, jointtypes, pipe materials, height of water table above pipeline, soil type, etc. The peakfactor above has included the contribution of infiltrations. The maximum allowableinfiltration rate shall be 50 litre / ( mm diameter.km of sewer length.day ).



2.1.15 Sewer Cleansing Velocities

The principal accumulants in sewers are slimes and sediments. The hydraulicrequirements for cleansing the sediments of sewer differ from those required forcleansing the slimes of sewer. a) Sediment Cleansing:

For the removal of sediments, the traditional design approach has been to set aminimum velocity to be achieved at least once daily. Minimum velocity values atfull bore of 0.8 m/sec are commonly specified. However, it has been found thatlarger pipe diameters require higher velocity to cleanse the sediment. This ismainly due to higher sediment depths in large diameter pipes

The movement of sediment is mainly a function of shearing stress needed todislodge sediment off the pipe wall. Similarly, shear stress is a function of pipediameter. Also, the type of sediment (i.e. grain size, specific gravity, cohesiveness)also influences the movement of sediment and, thus, the amount of required shearstress. For design purposes however, only a single sediment type needs to beassumed.

b) Slime Cleansing:

The removal of slime depends on the stress needed to shear sections of slime fromeach other or from the pipe wall. However, the shear stress required to removeslimes is not a function of pipe diameter. The necessary shear stress depends onthe thickness of slime to be removed and the pipe material. The degree of removalof slimes in any pipe material varies with the sewage velocity.

Removal of large portion of slimes requires high sewage velocities. It has beenfound that 85% or more of the sulphide producing slimes are removed when thegrade of the sewer is 2.5 times of that for sediment cleansing. In many instances, itmay not be practical to design a sewer to achieve such velocities due to theexcessive cost of constructing such a deep and steep sewer. Although increasingthe velocity up to the critical velocity will increase the amount of slime beingsloughed off, the rate of sulphide production remains substantially unaffected bythe thinner slime layer. Therefore, the selection of steep gradient to achievevelocities for full slime stripping is not a design requirement.

2.1.16 Pipe Roughness

Except for very high velocities, slime will always be present, which will increasethe pipe roughness. Abrasion by sediments will also impart a permanent increasein roughness. Pipeline roughness decreases as the velocity increases. However,there is insufficient data to accurately determine the pipeline roughness for a widerange of velocities or at small incremental changes in velocity. In addition, thevelocity of the sewage flow varies due to the factors such as daily fluctuations,different type of catchment, different stage of catchment maturity, etc. Therefore, itis not possible to select the pipe roughness with great accuracy.

Conservative roughness values as given in Table 2.1 shall be referred to whendetermining sewer discharge capacity.



Table 2.1a Normal Pipe Roughness for Gravity Sewer

Roughness, ks (mm) Pipe Material New Old

Vitrified Clay 0.06 1.5 Concrete: 0.15 3.0 Plastic 0.06 0.6

Old and new roughness values shall be used to determine the sewer cleansing andmaximum design velocities respectively.

Table 2.1b Normal Pipe Roughness for Force Mains for All PipeMaterials

Mean Velocity, V (m/s) Roughness, ks (mm) 0.8 ≤ V ≤ 1.5 0.6 1.5 ≤ V ≤ 2.0 0.3 V ≥ 2.0 0.15

2.1.17 Design of Gravity Sewer

Unless special arrangements have been agreed for the structural protection of pipes,the minimum depth of soil cover over the sewer shall be 1.2 m. Sewers are not tobe constructed under buildings.

The minimum size of public gravity sewers shall be 225 mm in diameter. Theminimum size of domestic connections to the public sewer shall be 150 mm indiameter. The maximum design velocity at peak flow shall not be more than 4.0m/s.

The design shall be based on the worst case scenario. The selection of the gravitysewer diameter and gradient to cope with the peak flow shall be based on thefollowing equations:

1. Colebrook - White Equation

⎟⎟⎠

⎞⎜⎜⎝

⎛+−=

2gDSD2.51ν

D 3.7kslogS D g (22V

whereV = velocityS = hydraulic gradient (m/m)ν = kinematic viscosity of water (m2 / sec)D = internal diameter (m)g = acceleration due to gravity (m/sec2)ks = roughness coefficient (m)



Typical ks values for various types of sewer pipes are presented in Table 2.2 below: Table 2.2 Typical Roughness Coefficient, ks

Material Roughness Coefficient, ks (mm) Concrete 0.3 to 3 Cast iron 0.26

Asphalted cast iron 0.12 Ductile iron 0.046

2. Manning Equations

V = R Sn

2 3 1 2/ /

where

V = velocity (m/sec)S = hydraulic gradientR = hydraulic radiusn = Manning coefficient Typical n values for various types of sewer pipes are presented in Table 2.3 below: Table 2.3 Typical Manning Coefficient, n

Manning Coefficient, n Material Good Condition Bad

Condition Uncoated cast-iron 0.012 0.015

Coated cast iron 0.011 0.013 Ductile iron 0.012 0.015

Vitrified clay pipe 0.010 0.017 Concrete 0.012 0.016

3. Hazen - Williams Equations

V = 0.849 C R 0.63S 0.54

where

V = velocity (m/sec)S = hydraulic gradientR = hydraulic radiusC = Hazen - Williams coefficient



Typical C values for various types of sewer pipes are presented in Table 2.4 below: Table 2.4 Typical Hazen-Williams Coefficient, C

Material Hazen-Williams Coefficient, C Top quality pipes, straight and

smooth 130 to 140

Smooth masonry 120 Vitrified clay 110 Old cast iron 100

Old cast iron in bad condition 60 to 80

Colebrook-White Equation has been deemed to give the most accurate results.However, the other equations, such as Hazen-Williams Equation and ManningEquation are easier to use and may be used too. Various design charts and tableshave been developed elsewhere to aid the manual computations.

2.1.18 Design of Force Mains

The minimum diameter of force mains (also known as rising mains) shall be 100mm diameter. There shall be no reduction in force main diameter with distancedownstream.

All bends on force mains shall be securely anchored to resist lateral thrusts andsubsequent joint movements.

Air release valves and washouts shall be provided at appropriate locations alongthe longitudinal profile.

For long and undulating force mains, hydraulic pressure transient analyses may berequired to ensure that the force main can cope with water hammer pressures.

Retention times in force mains must not exceed 2 hours without special precautionsto mitigate septicity.

All force main shall be designed to withstand at least 1.5 times the workingpressure. Approval from the Commission is required if any force main is to bedesigned to withstand pressure less than the pressure stated above.

Where retention times in the force mains exceed two hours and where concretepipe are laid downstream of the force mains, an induct vent shall be provided atmanholes receiving pumping discharges.

Friction losses are normally calculated using either Darcy - Weisbach (Colebrook-White) Equation or Hazen-Williams Equations. The forms of the equations aredifferent from the equations used to design gravity sewers. The equations arelisted below:



1. Darcy-Weisbach Equation

h fLVgD

f =2

2

where

hf = Friction lossf = Coefficient of frictionV = Velocity in the pipeg = Acceleration due to gravityD = Equivalent diameter of the pipeL = Length of pipe

The value of f is known to depend on the Reynolds number, Re, pipe roughness, ks,and pipe diameter, D, through the Colebrook-White equation as follows:

1 = -2 log ks + 2.51 sqrt (f) 3.7D Re sqrt (f)

The Reynolds number is defined as follows:

Re = VD v

where v is the kinematic viscosity of the fluid, typically equal to 1 x 10-6 m2/s forsewage.

The above equations together with the Moody Diagram are used to determine thecoefficient of friction, f.

2. Hazen-Williams Equation

hVC

LD

f = ⎛⎝⎜

⎞⎠⎟

6 821 85

1 167..

.

where

hf = Friction lossC = Hazen-William Coefficient (refer to Table 2.4)V = Velocity in the pipeL = Length of pipeD = Equivalent diameter of the pipe

Force mains shall be designed to handle the full range of flows from presentminimum to future peak.



The design velocity shall fall within the range of 0.8 to 3.0m/sec over the full rangeof design flows.

The hydraulic resistance of force main fittings and bends shall be included in thehydraulic design.

2.1.19 Vacuum Sewerage System

The design requirements of this Guidelines are the minimum requirements, and donot constitute in themselves a comprehensive design guide sufficient to ensure acorrectly functioning system. Every system must be individually designed, based onthe design parameters of the system employed; where proprietary systems areemployed, it shall be designed in compliance with the requirements of systemmanufacturers.

2.1.19.1 General

Specification of a vacuum sewage collection system shall only be considered wherethe life-cycle costs of a conventional gravity sewage collection system are clearlyshown to be higher.

This Guidelines assumes that all sewage transportation modes have been identified,their respective feasibilities evaluated against technical, environmental, financial,economic and other relevant criteria over the design life of the asset and thatvacuum sewage collection system has been confirmed as the best option. TheCommission may request for net present value (NPV) calculations for all optionsprior to approving construction of a vacuum sewage collection system.

a) Application of vacuum sewage collection system

Consideration shall be given to the use of the vacuum system in one or more of thefollowing circumstances:

i. Flat or undulating terrain; ii. Obstacles to the sewer route eg utility services, waterways; iii. Poor ground subsurface eg high ground water table, rocky terrains; iv. Isolated, low density communities; v. Where it is necessary to minimise the impact of construction work; vi. Where it is necessary to minimise the environmental impact.

b) Unit Processes

Typical unit processes for a vacuum sewage collection system is shown in typicaldrawing in Appendix A. The unit processes shall comprise of, but not limited to, thefollowings:-

i. Collection chamber for housing vacuum interface valve and also forming asump from which collected sewage is evacuated;

ii. A vacuum sewer network for the transport of sewage collected in thecollection chambers to a central vacuum station;

Conc

Ex



iii. A central vacuum station where the vacuum pressure is generated whichallows the sewage to be collected and forwarded to a receiving gravitysewer manhole or a sewage treatment plant.

c) Description of System

i) Collection chamber and vacuum pipeline

When the volume of sewage draining into a collection chamber reaches apredetermined level in the sump, the normally closed interface valve opens. Thedifferential pressure between the vacuum sewer and atmosphere forces the sewagefrom the collection chamber into the vacuum sewer via a crossover pipe. Typicalcrossover pipe connection is shown in typical drawings in Appendix A. After thesump is emptied, the valve closes. Air is admitted simultaneously with, or after, theadmittance of the sewage. The sewage is driven along the sewer until frictional andgravitational forces eventually bring it to rest in the lower section of the pipeprofiles. The characteristics of the vacuum sewerage system ensure that peakdischarges into the sewer are rapidly attenuated.

The vacuum sewer discharges into the vacuum vessel at the vacuum station. Thevacuum is maintained, by vacuum pumps, at a predetermined level. The sewage isgenerally pumped from the vacuum station by sewage discharge pumps.

ii ) Vacuum station

The vacuum station is similar to a conventional pumping station with the additionof vacuum pumps and a closed vacuum vessel. Typical vacuum station is shown intypical drawings in Appendix A. The level of the sewage in the vacuum vessel ismonitored by a level detection probe which activates the sewage discharge pumps.If the sewage rises too high in the vessel then a high level detection probe stops andlocks out the vacuum pumps to prevent the flow of sewage into the vacuum pumps.The vacuum in the vacuum vessel is maintained within the operational range bypressure switches.

d) Warranty of System Performance

Since the vacuum system involves proprietary design and equipment, specialistsystem designers shall be accountable to the performance of the entire vacuumsystem including both design and construction aspects. The specialist systemdesigners shall also specify clearly the specific maintenance and operationalrequirements of the system.

2.1.19.2 Collection Chamber

a) General design requirement

Collection chambers shall have sufficient capacity to store sewage discharged fromall connected properties for at least 6 hours in the event of a valve failure or similaremergency, which is sufficient to cover the IWK’s emergency response time.

KPKT/



The overflow storage time shall be based on the ultimate sewage design flow thatwill enter the collection chamber. The volume that can be used for emergencystorage shall be the volume contained in the collection chamber from the base of thecollection chamber up to the lowest ground level at any point served by the chamberas well as the volume contained in the gravity lateral sewers entering the collectionchamber.

Separate chambers shall be provided to serve properties at different elevationswhere there is a likelihood of sewage from one property flooding another property.

The chamber shall resist external forces and internal water pressure.

The preferred material of construction for collection chambers is pre-cast concrete.The two sections (the valve compartment and the collection sump) may be mountedvertically one on top of the other as shown in typical drawings in Appendix A. Thediameter of the sections may be as small as 1200mm or as large as 1500mm.

The collection sump requires a benching section that allows a scouring action fromthe sewage as it enters the suction pipe, thereby rendering the sump self-cleansing.The internal surfaces of the sump shall be both strong as well as resistant tocorrosive attacks from the collected sewage.

Where the interface valve is situated over the collection sump, a working platformshall be provided for allowing maintenance engineers to stand on when carrying outscheduled maintenance to the interface valve.

The sump shall be sufficiently vented to allow the intake of air without causing anoise nuisance and to ensure that the operation of the vacuum system does notunseal the water traps on the gravity drainage system.

b) Number of properties connected

The location of each collection chamber and the number of properties connected toeach collection chamber shall be specified in the Design Drawings / Calculations.

Sewage flow from the maximum number of existing or future properties that areproposed to be connected to a collection chamber shall be quantified, and theretention time of the collection chamber can be then established. The retention shallexceed 6 hrs.

c) Maximum flows to collection chambers

The maximum sewer design flow to a single vacuum interface valve collectionchamber shall not exceed 0.25 lit/s. Where single point flows in excess of 0.25 lit/soccur, multiple vacuum interface valves shall be installed. Typical multi-valvecollection chamber is shown in typical drawings in Appendix A.

d) Breather pipes

Some vacuum interface valves inhale and exhale air during their operation. This isaccomplished through a screened air pipe known as a "breather".

KPKT/

WSA



While breather bells are generally mounted inside the collection chamber, it may benecessary to mount them externally.

Each breather pipe shall be fitted inside the "breather bell" located at the top of thecollection chamber in an accessible location to allow their removal for maintenancepurposes.

e) Covers and frames

Collection chamber covers shall provide an access opening of at least 600 mmdiameter. Covers and frames shall be installed in accordance with the requirementsstipulated in Clause 2.3.

2.1.19.3 Vacuum Interface Valves

a) General

The interface valve shall fail safe in the closed position and shall prevent backflowsfrom the crossover pipes to the collection sump. When the valve is open, the flowpath shall not be obstructed by the valve mechanism. The valve shall evacuate atleast the batch volume each time it cycles. Valves installed in the sump shall becapable of operating when submerged provided that the breather pipe is notsubmerged.

The valve shall be installed in the collection chamber using demountable, re-useable“ No Hub” couplings suitable for vacuum service.

b) Level sensor

The valve shall be equipped with a sensor to determine the level of sewage in thecollection sump; this sensor shall be designed to be fouling resistant. Level sensorpipes shall not be less than DN/ID 45.

c) Interface valve controller

The controller shall open the valve only if there is a minimum partial vacuum of0.2bar below atmospheric available and shall maintain the valve fully open until atleast the batch volume has been evacuated. If the design provides for theintroduction of air after the sewage has been evacuated, the controller shall maintainthe valve open for a further period. The controller shall be adjustable so that a rangeof air to sewage ratios can be obtained. Controllers installed in sumps shall becapable of operating when submerged.

d) Explosion proof

The valve mechanism and controller shall be explosion proof if exposed topotentially explosive atmosphere.

WS

Exi



e) Life of valves and membranes

Every interface unit, comprising the interface valve, controller and sensor shall beexpected to last in excess of 25 years. Manufacturers shall clearly specify scheduledmaintenance, thus allowing the operators to keep the interface units in tip-topconditions at all times.

2.1.19.4 Vacuum Sewer Design

a) General

For a completely flat area, the length of a single sewer branch shall not be morethan 3km. However, the maximum limit of the pipe length would vary according tothe gradient achievable in that line. Specialist system designer shall provide adetailed hydraulic calculation for the vacuum sewer network.

Vacuum main routes shall be selected to:

i. Minimise lift; ii. Minimise length; iii. Equalise flows on each vacuum main; iv. Provide adequate access for operation and maintenance.

b) Sewer depth

Vacuum sewers, branch sewers and crossover pipe connections from the collectionchambers, shall have a minimum cover of 0.9 m to withstand the stresses arisingfrom traffic loads.

When sewers are not buried, they shall be protected from extremes of temperature,ultra-violet radiation and possibility of vandalisms.When sewers are suspended underside walkways or bridges, they shall be rigidlysupported so there is no visible sagging between supports. Supports shall withstandall static and specified dynamic conditions of loading to which the piping andassociated equipment may be subjected. As a minimum, consideration shall begiven to the following conditions:

i. Weights of pipe, valves, fittings, pipe protection materials, and medium inthe pipe;

ii. Reaction forces due to the operation of isolation valves; iii. Wind loadings on outdoor piping.

c) Sewer profiles

Pipeline profiles shall be self cleansing and prevent the accumulation of solids.Typical pipeline profiles are shown in typical drawings in Appendix A. Forcrossover pipes, the minimum distance between lifts shall be 1.5 m. Vacuum sewersshall have a minimum gradient of 1 in 500. Where the ground has a gradient of 1 in500 or more in the direction of flow, the vacuum sewer may be laid parallel to thesurface as shown in typical drawings in Appendix A.



i) Design tolerances

The chainage and invert levels of the pipeline(s) shall be determined to thefollowing levels of design accuracy and specified in the Design Drawings:

• Sewer chainage to the nearest 0.5 m.• Sewer invert levels to the nearest 0.01 m.

ii) Lift design

To provide for efficient vacuum transport to sewer extremities, the size ofindividual lifts shall be kept as small as possible. Many small lifts are preferable toone large lift. The change in invert at each lift shall not exceed 1.5 m. For vacuumsewers, the minimum distances between lifts shall be 6 m.

iii) Crossover pipe connection

Crossover pipe shall initially fall away from the interface valve and shall connectinto the top sector of the vacuum sewer contained within the angle of ± 60° aboutthe vertical axis as shown in Standard Drawing – Figure Vac7.

iv) Branch connections

All branch connections to vacuum sewers shall be by a Y-junction connected to thesewer above the horizontal axis as shown in Standard Drawing – Figure Vac8. Inplan, the angle of the Y-junction shall ensure that flow towards the vacuum stationis generated and backflows are minimised. No connection shall be made within 3mof a lift.

v) Water-logging

The profile shall ameliorate water-logging at any change in gradient even when aprolonged power failure occurs (both TNB supply and standby genset fail), and thevacuum interface valves continue to operate and admit sewage until the vacuumlevel reduced to the point when they will no longer open. When power is againavailable, the system shall be capable of recovering to normal operation withoutintervention by an operator.

d) Pipework and Fittings for Vacuum Sewers

The recommended material from which to construct vacuum sewers is PE 80 SDR13.6 rated polyethylene pipe. Pipe fittings shall be PE 100 SDR 13.6. Pipes shall beUV stabilised with carbon black which shall give the pipe a black colourthroughout. Four evenly spaced brown stripes shall be incorporated, thus readilyidentifying that the pipe is transporting sewage. The polyethylene pipe is selectedbecause it is both structurally strong and compatible with potentially chemicallyaggressive and abrasive flows in the sewage.



i) Pipe size

The suction pipe DN/ID shall not be greater than the DN/ID of the interface valve.The minimum diameter of crossover pipe shall be DN/ID 50 and shall be greaterthan the DN/ID of the suction pipe. Vacuum sewer shall have a minimum diameterof DN/ID 80.

ii) Jointing of PE pipes and fittings

PE pipes and fittings less than DN 160 shall be jointed using electrofusion fittings.Pipes and fittings DN 160 and larger shall be jointed with electrofusion fittings orbutt fusion welding.

iii) Warning system

To act as a warning to an excavation possibly carried out at a later date, the use of amarker tape laid 300mm on top of the pipe is recommended. This shall be a 150mmwide polyethylene and printed with a descriptive warning of the pipework below.

e) Isolation valve

The isolation valve clear opening shall be not less than the DN/ID of the pipe, andbe capable of sustaining a vacuum pressure of -0.8 bar(g).

Isolation valves shall be resilient seated gate valves with the body, bonnet, gate andbridge fabricated from ductile or cast iron. The stem shall be stainless steel, and thegate shall be encapsulated with EPDM. End connections to the valves shall beflanged.

i) Isolation valve installation

Each isolation valve shall be located in a chamber, which shall contain adismantling arrangement for replacement of the isolation valve if needed.

When isolation valves are buried, they shall have extension spindles and surfaceboxes.

ii) Isolation valve location

Means of isolating lengths of vacuum sewer to permit repairs or to locate faultsshall be provided at distances of not more than 500 m and on branch sewers longerthan 200 m.

2.1.19.5 Vacuum Station Design

a) General

It is desirable to have the vacuum station located as centrally as possible within thesewer network. This lends itself to a system with multi-branches hence givingadded operating and design flexibility. Ideally, the design capacity of a single-vessel vacuum station shall not exceed a population equivalent of 8,000 persons. A



dual-vessel station, or more than a single-vessel station that is completely isolated,shall be provided when the population equivalent exceeds 8,000 persons.

b) Vacuum station layout

A typical vacuum station layout is shown in typical drawings in Appendix A. Thevacuum station shall be divided into two main areas, an above ground plant roomand a below ground dry well.

The floor level of the dry well shall be designed to suit the invert levels of theincoming sewers, the vacuum vessel diameter and the dimensions of the selectedsewage discharge pumps.

The vacuum vessel, the sewage discharge pumps, valves and pipework associatedwith the sewage discharge pumps and a small sump to collect washdown water shallbe located in the dry well.

The plant room shall contain the vacuum pumps, control panel, standby dieselgenerator, vacuum pressure gauges, and moisture trap.

c) Vacuum vessel

Vacuum vessels shall be designed to meet the requirements of ASME Section VIIIDivision 1 – 2004 Edition. The vessel shell shall be constructed from mild steel orany other approved material.

Sewer inlets shall be provided with short radius elbows inside the vessel to directthe sewage inflow away from the sewage discharge pump suction connections andthe vessel walls.

A vacuum vessel may have up to five (5). incoming vacuum sewers connecteddirectly to the vessel. No inlet pipes shall be connected below the systememergency stop level. Sewage discharge pump suction connections shall beprovided at the invert of the vacuum vessel. The vacuum vessel shall be fitted withan externally mounted sight glass which is suitable for operation in a vacuum and iseasily removed for cleaning without decommissioning the vessel.

The vacuum vessel shall be provided with a DN 600 access opening, and the covershall be provided with a lifting eye. Wherever possible, the opening is preferablypositioned on the top of the vessel in order to minimise the size of the structurenecessary to house the vessel, this conserves valuable resource, reduces thefootprint of the building, and thus allows adjacent residences to enjoy more bufferspaces.

During the inspection or maintenance works, safe entry procedures shall be adheredto, according to the Department of Occupational Safety and Health (DOSH) codesof laws, by trained certificated operator, and that the vessel is decommissioned,with the access opening removed and discharge pipeworks at the two (2) draw-offpoints dismantled, and a forced air ventilation is applied.

It is important to ensure that the system would operate continuously in the face ofhaving the vacuum vessel temporarily out of service during an interval inspection.
C
onclude



The incoming sewage shall manually be bypassed to a mobile vacuum tanker via aflexible ribbed pipe. The pipe is of an adequate length to reach the bypass valvessafely. Typical bypass valve arrangement is shown in typical drawings in AppendixA.

d) Moisture trap

When mechanical vane vacuum pumps are selected, moisture trap shall be providedfor the vacuum pumps.

Baffles or moisture removing material shall be fitted inside each vessel to assistwith moisture removal.

e) Vacuum pumps

Vacuum pump capacity (Qvp) shall be rated. The selection of appropriate size ofvacuum pump is determined by the following four factors:-

• The peak flow of the sewage to be collected;• The length of the longest single sewer within the sewer network;• The total volume of the sewer pipework within the network;• Air to liquid ratio employed (ratio not less than 3).

i) Evacuation time

When the vacuum pumps, collection chamber and vacuum vessel have been sized,system evacuation time for an operating range of – 0.55 bar(g) to –0.65 bar(g) shallbe calculated using:

( )

Qvp

60VmtVoVvvVvs32

t×⎥⎦

⎤⎢⎣

⎡+−+⎟

⎠⎞

⎜⎝⎛

=

Where,t = system evacuation time, minutesVvs = volume of vacuum sewers, m³Vvv = volume of vacuum vessel, m³Vo = operating volume of vacuum vessel, m³Vmt = moisture trap volume (if fitted), m³Qvp = vacuum pump capacity, m³/hr

NOTE: In normal operation it is assumed that the vacuum sewers will beapproximately 1/3 liquid filled.

The system evacuation time, which is defined as the time period between thevacuum pump start and stop, shall be between 2 and 5 minutes.

ii) Selection of vacuum pumps

Vacuum pumps shall have sufficient capacity to serve the system. A minimum oftwo vacuum pumps of equal capacity shall be installed such that one pump can be



removed for maintenance without loss of system capacity. Vacuum pumps, whereused, shall be suitable for both continuous operation and for a minimum of 6 startsper hour.

iii) Vacuum pipework

ABS pipes and fittings shall be used for interconnecting pipework between thevacuum pumps and the vacuum vessel within vacuum stations.

Pipework shall be fully supported.

f) Sewage discharge pumps

Two sewage discharge pumps of equal capacity are recommended for use in avacuum station. Each pump shall be sized to discharge sewage at a rate at leastequal to the calculated design peak flow for the vacuum system. Sewage dischargepumps shall be capable of pumping unscreened sewage and suitable for immersedoperation in the event of the vacuum station dry well flooded. In normal operationthe dry well will not contain water.

Pumps may have a vertical or horizontal configuration.

Sewage discharge pumps shall be suitable for a minimum of 6 starts per hour.Equalizing lines connecting the discharge side of the centrifugal sewage dischargepumps to the vacuum vessel shall be installed if required to prevent cavitation or toensure that the pump inlet is always flooded.

Sewage discharge pumps shall be fitted with isolation valves to allow removal ofthe pump without disrupting the system operation.

Discharge pipework for each pump shall be fitted with a non-return valve and aresilient seated gate valve on the discharge side. Where the discharge pipework ismanifold, the final discharge pipe shall also be fitted with a non return valve. Thevalves shall be able to be operated from the vacuum station floor.

g) Vacuum gauges

150mm vacuum gauges calibrated to read 0 to -1 bar to an accuracy of ±2% shall befitted to the vacuum vessel and each incoming vacuum sewer. Vacuum gauges shallalso have bottom outlets fitted with lever-operated ball valves. All gaugediaphragms shall be suitable for use with sewage gases. The gauges indicate thevacuum pressure within each sewer and enable pressures within the sewer networkto be monitored.

h) Fire-fighting system

Fire-fighting system using carbon dioxide at the genset / fuel room shall beprovided at every vacuum station in accordance with Bomba’s requirements.



i) Odour control

Effective odour control system shall be provided to treat air vents from a vacuumstation to prevent malodour impacts being imposed on downstream residentialareas.

Biofilters shall be used to remove the odours from the vacuum pump exhaust gasescontaining toxic and odorous compounds by passing the gases through a naturalbiologically active filter medium.

j) Noise control

Vacuum station shall be acoustically designed and fitted with noise controlmeasures, as required to control noise to levels that comply with local council’sregulations.

k) Controls and Telemetry

i) Vacuum level control

Vacuum levels in the vacuum vessel shall be controlled by vacuum switches withan operating range of 0 to -1 bar(g). Their purpose is to control the operation of thevacuum pumps and to maintain the vacuum within the vessel inside the operatingrange. A minimum of four vacuum switches shall be provided to operate the dutyand assist pumps, and to provide a high and a low vacuum alarms.

ii) Level control

The level detection probes shall be mounted on the vacuum vessel. Their purpose isto control the operation of the sewage discharge pumps and to maintain the sewagewithin the vessel inside the operating range.

Probes shall be manufactured in one length without any screw joints along theirlength. Any form of float switch, including magnetic and ultrasonic types shall notbe permitted.

The level control system shall respond to the following sewage levels in the vacuumvessel:

Emergency stop level - stops vacuum generation;- sewage discharge pump operates;

Start level - starts sewage discharge pump;

Stop level - stops sewage discharge pump;

iii) Vacuum / sewage discharge pump control

The controls shall permit the selection of duty, duty assist (where provided) andstandby vacuum pumps and sewage discharge pumps and shall provide for theautomatic introduction of the standby units in the event of failure.


36 Volume 3

The electrical controls shall allow sequential operation of all pumps so that runningtimes are equalised. The standby pump shall automatically cut-in should the dutypump fail.

iv) Valve monitoring system / station telemetry

Valve monitoring and station telemetry systems are optional, but, shall beimplemented for larger schemes comprising more than 50 interface valves.

The open and closed status of interface valves shall easily be detected by the use ofa remote control via infrared/radio signals. Alternatively, system suppliers mayinstall a signal cable to relay this information to a display panel within the vacuumstation. All monitoring components installed at the collection chambers shall berobust and suitable for use in sewerage application.

Large schemes shall also include a telemetry section with volt-free contacts for eachcondition/alarm of the station equipment as shown in Table 2.5

Table 2.5 Condition/alarm of the station equipment

DESCRIPTIONS INPUT / OUTPUTStation power Failed / OKVacuum pump power Isolated / OKSewage discharge pump power Isolated / OKVacuum pump overload Tripped / OKSewage discharge pump overloadVacuum levelVacuum levelSewage levelIntruder alarmFire alarm

v) Emergency power generation

A back-up diesel generator shall be provideevent of an electric power disruption. The g120% of power for at least one vacuum pumother necessary equipment.

2.1.20 Computerised Sewer Designs

Manual computations for the hydraulic desifor many aspects using proprietary compprograms. However, there are many variatiohydraulic design, i.e. flow contributions infiltration, quantity of inflow, sedimeroughness coefficients, etc. It is therefore nprograms adopt the hydraulic design requSome proprietary softwares may not permit to the hydraulic design requirements givesoftware would be unsuitable.

Malaysian SewerageIndustry Guidelines

Tripped / OKLow / OKHigh / OKHigh / OK

Activated / OKActivated / OK

d to adequately run the station in theenerator shall be capable of providingp and one sewage discharge pump and

gn of a sewer network can be avoideduter software or in-house computerns possible for the different aspects offrom different sources, quantity of

nt cleansing requirements, pipelineecessary that the computer software orirements as detailed in this guideline.certain adaptations required to conformn in this guideline. As such, these



2.1.21 Design of Inverted Siphon

Inverted siphons are introduced along a gravity sewer line in order to pass under anobstacle (e.g. railway line, stream, culvert, etc). An alternative to an invertedsiphon for bypassing obstacles is a pump station. But such an option may beeconomically not viable. The profile of an inverted siphon encourages solidssettlement and accumulation and therefore they require more frequent cleaning.They must be avoided as much as practicable.

Inverted siphon shall consist of at least two or more parallel pipelines (or barrels).The minimum pipe size of a barrel shall be 225mm, and shall be provided withnecessary appurtenances for convenient flushing and maintenance. There will be aninlet chamber designed to divide the flow among the pipes by allowing each pipe tocome into operation in succession and an outlet chamber designed to preventeddies from carrying solids and sediments back into the siphons.Longer siphons shall be provided with hatch box with access for maintenance andcleaning. These siphons shall have independent washout facilities.

The manholes shall have adequate clearance for rodding. In general sufficient headshall be provided and pipe sizes selected to secure flow velocities of at least0.9m/sec for average flow. The inlet and outlet shall be arranged so that the normalflow is diverted to one barrel, and so that either may out of service for cleaning. Itschoice should be taken into consideration the operational and maintenance aspectof siphons. The siphons shall not have sharp bends, either vertical or horizontal.The horizontal leg of the siphon shall have a negative gradient of 8° to 10°, whilstthe rising leg shall be limited to 30° to 45° should space permitting. There shall beno change in pipe diameter along the length of the barrel. Pipes and pipe jointsused for siphons shall be designed at the appropriate pressure rating.

2.1.22 Structural Design of Sewers

The structural design of a buried sewer can be divided into the following twocategories:

a) rigid pipe

b) flexible pipe

All two structural designs shall take account of how the sewer is supported todetermine the loading which the sewer can safely withstand.

The structural design of a buried sewer normally considers only the structuralintegrity of the pipe cross section. Although not as critical as the structuralintegrity of the pipe cross section, the considerations for the ground conditions andsewer installation practices that will affect the longitudinal structural integrity shallnot be omitted.

There are many design approaches for each of the two structural design categories.However, there are only minor alterations among these different approaches. Somedesign approaches tend to give a more favourable prediction of performance for aparticular pipe material than other approaches. The use of standard designapproaches given in this guideline will prevent the selection of a particular design



approach purely to favour one material over another. Also, the followingrecommendations are only meant for general design aspects. Any design aspectsthat are not covered by this guideline, the designer shall refer to BS EN 752 or anyother standards deemed appropriate by the Commission.

a) Rigid Pipe Structural Design:

Pipes which are classified as rigid are:

i. vitrified clay pipe

ii. reinforced concrete pipe

The failure of a rigid pipe normally occurs by pipe fracture. Thus, for structuralperformance, the determination of the pipe ring crushing strength/load is required.This strength is determined using a three point loading test as described in therespective Malaysian standards for the above pipes. Both VC pipe and RC pipecan be made to achieve different ring strengths as defined in the standards.

When a buried rigid pipe is supported, the load which the pipe can safely withstandis higher than the load which caused failure in the three point loading test.

The improvement in load resistance provided by different pipe support designs isdefined by the bedding factor. Where the sewer is supported on granular material,such as crushed rock, the bedding factor becomes a function of the density of thegranular material and the height to which the granular material is placed above thesewer.

By varying the pipe ring strength and the pipe support, different load resistance canbe achieved.

The pipe support designs permitted by this guideline are limited to those in typicalbeddings in Appendix A. They include the following:

i. granular bedding/ Crusher rock

ii. concrete cradle

iii. concrete arch (with granular bedding)

iv. concrete surround

Granular bedding design shall be adopted wherever possible. Concrete support orarch designs should be avoided. This is due to the difficulty in achieving fullcontact of the concrete support with the pipe ring. A higher strength pipe incombination with crushed rock support is preferred over a lower strength pipe incombination with concrete support or arch designs.

It is important that the pipe bedding should be properly constructed to allow for theflexibility at the pipe joints and to ensure uniform pipe supports. Point supports orloads which may lead to pipe failure must be avoided.



The soil load to which a rigid pipe can be subjected to shall be determined fromMartson Load Theory. According to the theory, the soil load on a rigid pipe differsfrom that on a flexible or semi flexible pipe. The load on a rigid pipe is a functionof trench width, backfill soil type and trench depth. In a narrow trench, trench wallfriction reduces the load applied by the soil backfill. Therefore, wide trench givesa more conservative loading and shall be used to determine the load on rigid pipe.

Where vehicles will pass over the sewer and the sewer is laid with a cover depth ofless than 2.5 m, the sewer will be subjected to additional loads from such vehicles.The Boussinesq theory should be used to determine the loads from vehicles in thedesign.

The ultimate vehicle load to which the sewer will be subjected to shall be used forstructural design. Where the sewer may be subjected to construction traffic or mayhave temporary shallow cover during installation, structural design must examinesuch loading conditions to ensure the sewer can withstand such temporary vehicleloadings.

Determination of vehicle loading shall be in accordance with AS 3725 (Loads onburied concrete pipes) and AS 4060 (Loads on buried vitrified clay pipes.)

Loads on buried rigid pipe for field conditions and for main roads can be found inSimplified Tables of External Loads on Buried Pipelines published by the UKTransport Research Laboratory.

b) Flexible Pipe Structural Design:

Pipes which are classified as flexible are:

i. PE pipe

ii. GRP pipe

iii. ABS pipe

iv. Steel pipe

The mode of failure of a flexible pipe is usually by excessive pipe ringdeformation, except for GRP pipe which may be by excessive pipe ring strain. Theoccurrence of such a GRP pipe failure depends on the wall thickness.

Normally a standard long term allowable ring deflection is applied for all flexiblepipe. A 5% long term deflection limit has been the most commonly adopted limitand shall be used except for steel pipe with cement mortar lining. For steel pipewith cement lining, a 2% deflection limit shall be used. Where surface settlementis critical, a lower allowable deflection limit may be adopted.

The resistance of a flexible pipe to ring deformation is classified by pipe ringstiffness. The stiffness classification is derived from a two point short term loadingtest. It is a function of the loading force divided by the specified test deflection.Flexible pipe can be made to achieve different ring stiffness by varying the wallthickness. For PE pipes, the ring stiffness can also be varied by varying the wallstructure.



Similar to rigid pipe, the loading which a flexible pipe can withstand can beincreased when the pipe is supported. For flexible pipes, this external ring supportis more critical. Without it, a flexible pipe would fail under the loads applied byusual soil cover for gravity sewers and under vehicle loads for shallow cover forcemains.

By varying the pipe ring stiffness and surrounding soil stiffness, different loadresistance can be achieved for flexible pipe. Flexible pipe must be completelyembedded in crushed rock, with the rock to be finished at 150 mm over the top ofthe pipe. Crushed rock will give a uniform support around the pipe.

The soil load used for structural design for flexible pipe support shall be the prismload or the weight of the column of soil directly above the pipe. Marston LoadTheory mentions that this column of soil is partly supported by friction provided byadjacent soil. Therefore, this frictional support of soil column causes the load onthe flexible pipe to be less than the weight of soil directly above the pipe. Thisfrictional support may be lost with time and the design using prism load representsa conservative design.

Where vehicles will pass over the sewer and the sewer is laid with a cover depth ofless than 2.5 m, the pipe will be subjected to additional loads from such vehicles.The Boussinesq theory should be used to determine the loads from vehicles in thedesign approach in this guideline.

The ultimate vehicle load to which the pipe will be subjected to shall be used forstructural design. Where the pipeline may be subjected to construction traffic orhave a temporary shallow cover during installations, structural design mustexamine such loading conditions to ensure the pipeline can withstand suchtemporary vehicle loadings.

Granular bedding design shall be adopted wherever possible. Typical details ofgranular bedding for flexible pipe is given in Appendix A. The structural design offlexible pipe support must be in accordance with Australian Standard AS/NZS2566, which uses a modified form of Spangler’s equation for the determination ofpipe deflection. This Spangler equation incorporates Leonhardt’s factor to accountfor the change in support provided by surrounding soil stiffness when the trenchwidth is varied.

For force mains with shallow cover, structural design of flexible pipe may not benecessary. However, when the structural design of flexible pipe for such a forcemain is undertaken, the re-rounding effect of internal pressure should be ignored toallow for the worst case design, which occurs when the line is out of service.

2.2 Manhole

2.2.1 General

Pre-cast concrete manholes shall conform to MS881 and BS5911. Manholes shallbe constructed with pre-cast concrete sections surrounded by an in-situ concretesurround. Protecting lining/coating shall be provided to prevent corrosion of the



concrete due to sulphide attack. Walls shall be either rendered with sulphateresistant cement mortar at least 20mm thick or lined with PVC, HDPE or epoxycoating. PVC or HDPE lining shall be at least 5mm thick. Continuity of the liningshall be provided by means of welding or fusing each individual sheet to the nextprior to the concrete curing. The epoxy coating shall either be high build tar epoxysystem complying with AS 3750.2 and applied in two or more coats to give a totaldry film thickness of not less than 500µm; or high build micaceous iron oxidepigmented epoxy system complying with As 3750.12 and applied in two or morecoats to give a total dry film thickness of not less than 250 µm. The benching shallbe protected with epoxy coating, high alumina cement mortar, or equivalence.Only materials and application processes approved by the Commission may beused.

Brick manholes shall not be used, due to the high risk of excessive infiltration.

Details of manhole types and construction are shown in Appendix A. Straight backtype taper top shall be used while reducing slabs type are acceptable as alternative.Any other type of pre-fabricated manhole will require prior approval of theCommission.

The minimum diameter of manhole chambers constructed from pre-cast concreterings shall be as given in Table 2.6 below:

Table 2.6 Minimum Manhole Diameters

Depth to Soffit fromCover Level (m)

DN Largest Pipe inManhole (mm)

Min. InternalDimensionsa (mm)

< 150 1000 225 to 300 1200 375 to 450 1350 525 to 710 1500 820 to 900 1800

< 1.5

> 900 Subject to designer’srequirements based

on site condition < 300 1200

375 to 450 1350 525 to 710 1500 820 to 900 1800

> 1.5

> 900 Subject to designer’srequirements based

on site conditionNote:a These sizes apply to straight-through pipes; larger sizes may be required forturning chambers or chambers with several side branches or where specificmaintenance requirements are necessary, e.g disconnecting traps.

An induct vent shall be provided at manholes receiving pumping discharges whereretention times in the force mains exceed two hours and where concrete pipe arelaid downstream of the force mains. The induct vent shall have a diameter ofapproximately one half of the force mains but shall not exceed 300 mm in



diameter. The top of the concrete support of the vent shall be built up above floodlevel. Details of the induct vent are shown in Appendix A.

Provision of back-drop manhole shall be based on the following criteria:-

a) for pipe size equal to 225 mm or less, back-drop manhole shall be providedwhen the difference in invert level is equal to 900 mm or more.

b) for pipe size more than 225 mm, back-drop manhole shall be providedwhen the difference in invert level is equal to 1000 mm or more.

2.2.2 Manhole Location

Unless otherwise agreed by the Commission, all manholes shall be sited in publicroad reserve so that access can be gained for maintenance purposes. Manhole shallbe provided for the following locations:

i. the starting end of all gravity sewers, this may be replaced by a terminal layout

ii. every change in direction or alignment for sewers less than 600 mm in diameter

iii. every change in gradient

iv. every junction of two or more sewers

v. every change in size of sewer

Unless adequate modern cleaning equipment is used for the maintenance of thesewer, the spacing between manholes shall not be more than 100 m for sewers lessthan 1.0 m in diameter. For sewers with diameter larger than 1.0 meter, the spacingbetween manholes shall not be more than 150 m.

Where site conditions prevent manhole construction on the existing public sewer, amanhole shall be provided on the connection pipe as near to the public sewer aspossible.

The connections, details, and methods of manhole construction not covered in thisguidelines shall be in accordance with MS 1228. In addition, the current policiesof the Commission with respect to safety and operation shall be strictly followed.

2.2.3 Pipe Lengths from Manhole

To prevent the differential settling of the manhole and the connecting sewer frombreaking the sewer pipe, rotational flexibility in the sewer close to the manhole isrequired. A single flexible joint placed immediately outside the entry to themanhole is not sufficient to solve the differential settlement problem, unless graded(governed by gradient permissible range) to connect directly to match invert levelof manhole channel, if unable to match invert level. A short length of “rocker pipe”having a flexible joint at both ends shall be provided. A 600 mm length short“rocker pipe” is sufficient to provide the rotational flexibility required for mostcircumstances in small diameter pipelines (≤300 mm). For larger pipe, a 900mmlength short “rocker pipe” shall be provided. Refer to drawings in Appendix A.



2.2.4 Structural Design Considerations for Manhole

i. Concrete used in situ shall be 25Mpa Portland cement unless shownotherwise by the Qualified Person.

ii. A cement blinding with a minimum of 50 mm thickness shall be placedbefore pouring the concrete manhole base.

iii. The base of the manhole shall not be less than 300 mm thickness, which ismeasured from the channel invert.

iv. Channel inverts shall be laid accurately to meet entry and exit pipe inverts.

v. The channel invert shall be graded evenly between the entry and exit pipes

vi. Flexible joints shall be provided at the exit and entry of the manholes andshall be placed immediately outside any poured-in-situ concrete surround.

vii. Joints between the pre-cast chamber rings shall be sealed with suitablemortar, which can be high alumina cement mortar or equivalence.

viii. The top of the benching shall be sloped at 1 in 12 towards the channel.

ix. The finish surfaces of cast in-situ concrete structures shall be trowelledsmooth without poke holes or exposed aggregate.

x. A minimum of 150mm thick Grade 25 concrete in-situ shall be encased tothe precast concrete section. Brick manholes shall not be used.

xi. Box outs sealed with bricks or equivalence shall be made for any proposedconnections.

xii. Drop connection pipes and fittings in the manhole shall be of the samediameter and material as the connecting sewer.

xiii. A factory pre-cast intermediate slab shall be provided at every 3 metersdepth and placed at half of the manhole depths. The slabs must have holesfor ventilation.

xiv. Pre-cast reinforced concrete landing, cover slap and flat top’s undersidesshall be painted with 2 layers of coal tar epoxy.

xv. Manhole covers in roads shall be set to the road profile and shall be flushedwith the road surface.

xvi. Manhole covers in unimproved areas shall be set at an elevation to prevententry of surface water.

xvii. Manhole frame surrounds shall be filled with 1:3 cement mortar.

xviii. Field coatings to manhole covers and frames shall be applied to surfacesthat are clean, dry and free from rust.

xix. Bolted-in steps are not permissible in all manholes. Provision shall beprovided for portable ladder for access. The lightweight removable laddersshall be used in manholes where they can easily be inserted and securedfrom the surface, in order to deter unauthorized access to sewers.

xx. Maximum depth shall be equal or less than 9 meter and all manholes deeperthan 6 meter are subjected to the Commission’s prior approval. Dependingon the catchment are and size of sewer pipe, manholes deeper than 9 metermay be considered for the Commission approval.



xxi. Precast or cast in-situ concrete base of minimum grade 20 with 1 layer ofA6 BRC, 300 mm thick or to Qualified Person’s design shall be providedunder poor soil condition including piling, if necessary.

2.3 Manhole Covers and Frames

2.3.1 General

Manhole covers and frames shall comply with the specifications in this guidelineand BSEN124. Where the specifications in this guideline contradict thespecifications given in BSEN124, the specifications in this guideline shall takeprecedence.

2.3.2 Load Class

Manhole covers and frames shall be capable of bearing wheel loads of up to 400kN and, as such, shall meet the test load requirements for Class D400 manholecovers and frames given in BSEN124.

2.3.3 Material

The material for manhole covers and frames shall be of spheroidal or nodulargraphite iron (otherwise known as ductile iron) complying with the requirementsspecified in BSEN1563 for Grade 500/7.

The production, quality and testing of spheroidal graphite cast iron shall complywith ISO 1083.

2.3.4 Dimensions, Marking and Surface Finish

The manhole covers shall be free of defects which might impair their fitness foruse. The dimensions, marking and surface finish of manhole covers and frames shallcomply with the requirements given in Figure A.1 to A.4 in Appendix A. Tolerance on dimensions shown in Figures A1 to A2 shall be ± 1 mm. The castingof markings shall be clearly legible.

2.3.5 Seating

When a random cover is placed in a random frame, the adjacent top surfaces of thecover and frame shall have flushness of level within ± 1 mm. The manholes covers shall be compatible with their seatings. These seatings shallbe manufactured in such a way to ensure stability and quietness in use.



2.3.6 Casting

All cast units shall be cleanly cast and free from air holes, sand holes, cold shutsand chill. They shall be neatly dressed and carefully fettled. All castings shall befree from voids, whether due to shrinkage, gas inclusions or other causes.

2.3.7 Protective Coating

All surfaces of manhole covers and frames shall be supplied coated with either a:

i. hot applied bituminous material complying with BS 4147 Type IGrade C

ii. cold applied bituminous material complying with BS 3416 Type II

Immediately prior to coating, surfaces shall be clean, dry and free of rust. Thecoating shall be free of bare patches or lack of adhesion. The mean thickness shallbe no less than 70 µm and the local thickness shall be no less than 50 µm.

2.3.8 Water-tightness

No visible leakage shall occur between the manhole cover and its seating in theframe when tested in accordance with Appendix E of AS 3996.

2.3.9 Safety Features

Manhole covers shall be provided with locking device and hinge to prevent rockingdue to traffic and to provide a theft proof design. a) Locking Devices Locking devices shall be either bolts and nuts or a mechanism with a special keydesign. The mechanism shall be able to be integrated with the covers and can alsobe used as a lifting device. All the mechanism for locking device shall be ofstainless steel in accordance with BS EN ISO 3506. Bolts and nuts for lockingdevices shall be hexagonally headed, complying with BS3692. b) Hinge All manhole covers shall be hinged. The hinge shall be designed such that, whenin the open position, they shall be secured by a positive mechanical retainer toprevent accidental closure of the covers. The opening angle of hinged covers shallbe at least 100o to the horizontal. If hinge bolt is used for coupling separatesections of covers and frames, it shall be of stainless steel in accordance with BSEN ISO 3506.

2.3.10 Product Certification

Manhole covers and frames shall be certified as complying with the requirementsof this specification. The product testing for certification purposes shall beundertaken by SIRIM QAS, IKRAM QA services or other third party certificationbody. The approval of the product shall be from the Commission.



The quality control of the certified manhole covers and frames shall meet therequirements given in Clause 10 of BSEN 124. However, the final inspection andtests and the frequency of tests/inspection shall not be as shown in Table A3 ofBSEN 124. Instead, the specifications as shown in Table 2.7 below must befollowed. All final inspection and test documents shall be retained for at least 5years.

Table 2.7 Final inspection and testing

Final Test/Inspection Frequency Markings legibility inspection Every unit

Casting defects inspection Every unit

Protective coating inspection Every unit

Locking devise inspection Every unit

Seating flushness of cover in frame 1 per 20 Measurements of all dimensions 1 per 100

Load Class Test 1 per 100 Water-tightness Test (only applicable for covers required to be watertight)

1 per 100

Protective coating thickness measurement 1 per 200

2.4 Design of Network Pump Stations

2.4.1 Specifying of Network Pump Stations

Network pump stations shall be provided only where:

i. Sewage flow by gravity is not allowed by the topography

ii. Excessively deep and expensive excavation for sewer installations will berequired

iii. Sewage needs to be delivered from an area that is outside the naturaldrainage catchment of a sewage treatment plant

2.4.2 General Requirements

i. Network pump stations shall be preceded by screens to protect pumps frombeing damaged or clogged.

ii. The type of pump used must be suitable for sewage application. Waterpumps must not be used as they are not designed to transfer sewage.



iii. Drainage of dry wells and valve pits shall be provided. Drainage lines shallbe equipped with back flow protection to ensure that the chamber is notflooded.

iv. Wherever possible, the wet well shall not be housed within a buildingstructure with insufficient ventilation.

v. Where separate valve pits are used, then the connecting pipes shallincorporate at least two flexible joints to allow for differential settlement.

vi. The designer shall ensure that his/her designs comply with all relevantlegislation, standards, guidelines and requirements, and its latestamendments.

vii. Access and appropriate parking shall be provided at all times for emergencyvehicles, maintenance vehicles and ancillary equipment.

viii. Adequate protection against lightning shall be provided

2.4.3 Buffer Requirements

In order to minimise the nuisance of odours from pumping stations, buffer zoneshall be provided at all sides. The zone shall be at least 20 m from the pumpingstation fence to the nearest habitable building fence. The presence of a pumpingstation in any development may draw negative visual impacts. To minimise thevisual impact of surface structures of the pumping station, landscaping shall beprovided. Landscaping shall comprise of trees that are non-shedding to minimisemaintenance. The buffer requirements are shown in Appendix A.

Under conditions where there exists the potential of odour nuisance to the nearesthabitable building property line within residential and commercial developmentdespite having the minimum buffer zone, such odour shall be minimised to thelowest possible level and in compliance with the EQA.

2.4.4 Pipework Requirements

i. Pipe work shall be of ductile iron with approved internal lining. Otherapproved material by the Commission may be used.

ii. External surface of pipe work in chambers and wells shall be epoxy coated.

iii. Buried ductile iron pipe shall have polyethylene sleeving.

iv. Pipe work shall be adequately supported

v. Flanges shall be located at least 150 mm away from structures.

vi. Dismantling joints such as bends shall be provided.

vii. Pumping thrust shall be resisted using pipe supports

viii. All internal pipework within the pump station shall have flanged jointsunless the pipe selected has special jointing requirements.

ix. Flexible couplings should be used where they will facilitate dismantling andaccommodate vibration.



2.4.5 Wet-well Requirements

i. Suction channels shall be designed to avoid "dead zones", i.e., preventsolids and scum accumulation.

ii. Minimum hopper bottom slope shall be 1.5 vertical to 1.0 horizontal.

iii. Automatic flushing of grit and solids is required for plants of PE > 2,000.

iv. The difference between stop and start levels shall be a maximum of 900mm and a minimum of 450 mm.

v. The difference in level between start or stop of duty and assist pumps shallbe greater than or equal to 150 mm.

vi. The minimum sump volume required shall accommodate the pumpingcycle as per Table 2.4.

vii. Benching shall be designed to minimise deposition of solid matter on thefloor or walls of wet wells. The minimum slope of benching shall be 45o tothe horizontal.

viii. Benching shall preferably extend up to the pump intake.

ix. Self cleansing pumps shall be provided.

x. Access into wet wells can be by vertical rung ladders with a maximumheight of 6 m. When the height exceeds 6 m, intermediate platforms shallbe provided with a change in direction of the ladder. Safety cages shall beprovided for ladders exceeding 6 m.

xi. Access covers shall have a minimum clear opening of 600 mm diameterand be sufficiently large to withdraw pumps vertically.

xii. Access covers shall be capable of being lifted by, at most, two operators.

xiii. On small pump stations (PE < 500), the practice is to provide differencebetween the cut-in and cut-out levels, the storage volume equal to 2 to 3times the peak flow into the wet-well in litres per minute merely to protectthe starting equipment from overheating and failure caused by too frequentstarting and stopping.

xiv. Emergency by-pass shall be provided either at any suitable manhole or wet-well. The discharge of the by-pass is preferred to the nearest watercourseand not to the perimeter drain of the pumping station. However, if this isnot available then discharge to the nearest surface drain is allowed.

xv. All wet-well shall be opened and come with stainless steel or other non-corrosive handrails. If stainless steel tubing is used, it shall be in-filled withconcrete.

2.4.6 Dry-well Requirements

i. The size of dry well depends primarily on the number and type of pumpsselected and on the piping arrangement.

ii. The requirement of pump installation is to provide at least 1.0m from eachof the outboard pumps to the nearest side wall and at least 1.2m betweeneach pump discharge casing.



iii. Sufficient room is required between pumps to move the pump off its basewith sufficient clearance left in between the suction and discharge pipingfor site repairs, inspection or removal from the pit to the surface for repairs.

iv. Consideration should be given to the installation of monorails, lifting eyesin the ceiling and A-frames for the attachment of portable hoist cranes andother devices.

v. Provision should also be made for drainage of the dry well to the wet well.

2.4.7 Structural Requirements

i. Substructure shall be constructed of reinforced concrete with sulphateresistant cement to resist aggressive soils and groundwater.

ii. Below ground walls shall be waterproofed and protected against aggressivesoils and ground water.

iii. Safe and suitable access to the wells shall be provided.

iv. Internal walls shall be made resistant to sulphide corrosion by coating withhigh alumina cement or equivalent coatings.

v. A penstock shall be installed upstream of the wet well to isolate the pumpstation.

vi. For safety and operational reasons, a double penstock system may berequired at specific plant.

vii. The penstock spindle shall extend to pump station ground level and shall besuitably positioned to allow unrestricted operation of the penstock.

viii. Access platforms shall be provided at all locations where dismantling worktakes place.

ix. Access covers shall be hinged with a lifting weight not exceeding 16 kg.

x. Internal walls shall be made resistant to sulphide corrosion by coating withhigh alumina cement mortar lining, PVC lining or epoxy coating. Othermaterials used under special circumstances are subjected to approval fromthe relevant authority.

xi. Penstock greater than 610mm x 610mm shall be motorised and come withmanual overwrite switches. The actuator shall be located above groundlevel and above flood level for easy access in the event of flooding.

xii. Protection against falling shall be provided by means of handrails atwalkways and other working areas, where the fall equal or exceeds 1.5 m.

xiii. Edge protection by means of kick plates of at least 50 mm in height shall beprovided, where the drop is equal or exceeds 2.0 m.

xiv. Proper drainage shall be provided at the collection bin area to ensure thatliquid collected could be channelled back to the pump sump.

2.4.8 Ventilation Requirements

i. Ventilation shall be provided for all hazardous zones of the pump station.

ii. Covered pits shall have mechanical ventilation.

iii. Separate ventilation shall be provided for wet wells and dry wells.



iv. Lighting systems shall be interconnected with ventilation.

v. Permanent ventilation rate and air changes shall comply with MS 1228.

vi. uPVC pipe is not permitted to be used as ventilation ducting between wet-well and dry-well.

2.4.9 Odour Control

i. the potential for odour generation, its impact and treatment, shall beconsidered in all aspects of design

ii. isolate odorous gasses from general ventilation exhausts by containingidentified odour generating sources with a separate local exhaust system

iii. containment of the odour sources shall be by installing lightweight andcorrosion resistant covers/enclosures designed for practical operation andmaintenance works

iv. the local exhaust odorous air shall be conveyed through well designed andbalanced ductworks by a centrifugal fan to an effective odour treatmentequipment

2.4.10 Requirements for Lighting and Electrical Fittings

i. Wet wells and dry wells shall be adequately lit.

ii. Electrical installations shall be water proof, vapour proof and explosionproof.

iii. If lights are fitted outside the well, then a spotlight system may be used toprovide adequate illumination.

iv. If portable lighting is used, proper ancillaries shall be made available.

v. Equipments shall be sited above the highest water level.

2.4.11 Acceptable Pump System (Fixed Speed Pumps Only)

The acceptable pump types are: i. Centrifugal

ii. Screw

iii. Screw Centrifugal

Pumps are to be equipped with an auto restart mechanism to allow for automaticpump restart after power supply has resumed from a power failure. Pumps shall beequipped with protection accessory, e.g. thermal sensor, leakage sensor, etc. Drywell mounted pumps shall be equipped with auxiliary services such as cooling andgland seal water supply.

Guide rail, lifting device and other wet well fittings must be fabricated of stainlesssteel, that is corrosion resistant. The use of hot dip galvanised iron is notrecommended.



Pre-fabricated pump stations are acceptable for small installations of PE less thanor equal to 2,000.

2.4.12 Valve Requirements

2.4.12.1 Generali. All valves shall be anti-clockwise opening.

ii. All valves shall be suitable for use with wastewater and shall be designed toprevent retention of solids.

iii. All valves shall be identified by durable name plate. Direction of flow shallbe stamped on the valve body.

iv. Bodies and cover for all valves shall be made of ductile iron to BS EN1563: 1997. Special protective surfaces finishing by short blasting andfinished externally with epoxy corrosion resistant coating shall be provided.

2.4.12.2 Gate Valvei. Gate valves shall be of the non-rising screw wedge-gate type, double-faced

ductile iron made and with resilient seated.

ii. Gate valve shall conform to MS 1049, BS 5163 EN 1074 Part 2 or BS EN1171: 2002.

iii. The wedge of the gate valves shall be coupled and integral to the wedge hutin dezincification resistant high tensile brass (CZ 132) conforming to BSEN 2287 2: 1993, ISO 2872: 1985.

iv. The spindle of the gate valve shall be of the inside screw non-rising withmachined square or acme threads and operated by a handed or tee-key.

v. Resilient seat valves shall have EPDM covered gates with inside screwnon-rising stem. Stem shall be stainless steel conform to BS EN 10088-3:2005.

2.4.12.3 Check Valvei. Check valve shall be of approved by the Commission and suitable for their

intended used and shall comply to BS 12334: 2001.

ii. Check valves of non-slam swing type with extended spindle if necessaryshall be provided at the upstream of a flow detection device.

iii. Only single disc type of check valve shall be used.

iv. The uses of internal counter weights are not permitted for check valve.

v. Type non-slam check valve shall be of the full body type, with a domedaccess cover and only on moving pant, the flexible disc.

vi. Disc of check valve shall be of precision molded NBR to BS EN 681-2:2000. the disc shall be of one-piece construction, precision molded with anintegral o-ring type sealing surface, and contain alloy steel and nylonreinforcement in the flexible use area.



vii. In the absence of check valve, the reverse rotation of the pump shall notexceed 150% of the rated speed or limit set by the manufacturer.

viii. Tapping (12 mm BSP) shall be located upstream and downstream of checkvalves.

2.4.13 Requirements for Level Controls

i. Either floats, electrodes or ultrasonic level controls may be used for start-stop level of pumps. Those level controls with environmental friendlyfeatures are recommended.

ii. Ultrasonic level control is recommended due to its clog-free nature.

iii. Non-mercury type floats are recommended.

iv. Hollow tube electrodes are not acceptable.

v. Level controls shall be placed where they are not affected by the turbulenceof incoming flow and where they can be safely removed.

vi. When floats are used, cable hanger shall be installed.

2.4.14 Requirements for Alarms

i. Provision of alarms shall be considered inclusive of flammable gas, fire,high water level, bearing temperature, motor temperature, pump failure,power failure and vandalism.

ii. An alarm system should have an emergency power source capableoperating for at least 24 hours in the event of failure of the main powersupply and shall be telemetered thereto.

iii. Where no such facility exists, an audio-visual device shall be installed atthe station for external observation.

2.4.15 Requirements of Hydraulic Design and Performance

The followings items shall be provided: i. System curves

ii. Pump curves

iii. Operating point of pumps with respect to flow and total dynamic head(TDH)

iv. Operating characteristics such as efficiency, horsepower, motor rating andNPSH

2.4.16 Maintenance Considerations

i. Mechanical and electrical equipment selected shall be robust and reliableand shall require minimal maintenance.

ii. Consideration should also be given to the availability of spare parts. iii. The provision of appropriate lifting hoists and beams, and lifting eyes or

similar features on heavy equipment, shall be considered.



iv. Complete sets of current general arrangement and sectional drawings,operational, maintenance and service manuals, circuit diagrams and partslists shall be supplied and be available at all times.

2.4.17 Hazard and Operability

i. All pumping station design shall give consideration to all potential hazardand operability of design.

ii. HAZOP study may need to be conducted for pumping station design toidentify the hazards and operability issues.

iii. The need for HAZOP study shall comply with requirements stipulated theVolume II.

2.4.18 Other Requirements

Also refer to MS1228 for additional requirements.



Table 2.8 Recommended Design Parameters for Pump Stations (continue on next page)

Design ParametersDescription Unit PE ≤1,000 1,000 < PE ≤ 5,000

Type of station Wet well Wet well

Number of pumps(all identical and worksequentially)

21 duty,

1 stand-by(100 % standby)

21 duty,

1 stand-by(100 % standby)

Pumps design flow each at Qpeak each at Qpeak

Maximum retention time at Qave min 30 30

Min pass through openings mm 75 75

Minimum suction and dischargeopenings mm 100 100

Pumping cycle(average flow conditions)

start/hour

6 min15 max

6 min15 max

Lifting device* lifting davit lifting beam and block

* - Weight < 16 kg: Manual lifting- 16 kg ≤ Weight ≤ 250 kg: A davit or ‘A’ frame shall be arranged to allow items lifted by using manual chain

hoist to be projected on a 1.2 m truck tray and positioned at 2m above road level. In the pumpstation, motorized hoist is required for lifting weight exceeding 100kg.

- Weight > 250 kg: A gantry with motorised hoist shall be arranged to allow items to be projected on a 1.2m truck trayand positioned at 2m above road level truck tray.



Table 2.8 Recommended Design Parameters for Pump Stations

Design Parameters

Description Unit 5,000 < PE ≤ 20,000 PE > 20,000

Type of station wet well or dry well up to 10,000 PE10,000 PE above – wet well and dry well

wet well and dry well

Number of pumps(all identical and worksequentially)

4 (2 sets)1 duty, 1 assist,

per set(100 % standby)

6 (3 sets)1 duty, 1 assist,

per set(50 % standby)

Pumps design flow each at 0.5 Qpeak each at 0.25 Qpeak

Maximum retention time at Qave min 30 30

Min pass through openings mm 75 75

Minimum suction and dischargeopenings mm 100 100

Pumping cycle(average flow conditions)

start/hour

6 min15 max 6 - 15

Lifting device* Mechanical and block mechanical

* - Weight < 16 kg: Manual lifting- 16 kg ≤ Weight ≤ 250 kg: A davit or ‘A’ frame shall be arranged to allow items lifted by using manual chain

hoist to be projected on a 1.2 m truck tray and positioned at 2m above road level. In the pump station,motorized hoist is required for lifting weight exceeding 100kg.

- Weight > 250 kg: A gantry with motorised hoist shall be arranged to allow items to be projected on a 1.2m truck tray andpositioned at 2m above road level truck tray.



2.5 Interceptors

All development schemes including individual premises that involve any sewerageworks are vetted by the Director General. As part of this vetting, a check is madeon the means of protecting public sewers from the discharge of prohibited matterssuch as oil, grease, petrochemicals, fats and solid food wastes. These matters canlead to congealment, constriction and blockage of sewers and pipelines and canalso present hazards for sewer operations and maintenance. Therefore, suitableinterceptors must be provided on the sewerage systems of garage workshops,engineering workshops, canteens or any premises that collect such matters. Thedesign specfication may be acquired from the Director General for such a system.

2.5.1 Oil Interceptors

Oil interceptors shall be provided in drain lines from areas such as garages, parkingzones, service stations, machine shops and industrial plants where oil sedimentsand other volatile liquids are generated.

Oil interceptors shall be designed in such a way that pollutants that are lighter thanwater liquid are trapped in a chamber and are prevented from being discharged tothe public sewer. The chamber shall be normally fitted with a device to trapsediments and heavy particles that settle to the bottom. The removal of thesesediments is required periodically.

Intercepted oils shall be capable of being drained off for storage from suitable drawoff points on a continuous operational basis.

The interceptor shall be sized to accommodate the volumes of liquid likely to bedischarged into the drainage system and the trapped pollutants.

2.5.2 Grease Traps

Grease traps shall be provided in drain lines from areas such as restaurants,canteens, food processing and animal product or feeds factories, where grease andfat are likely to present in wash down waters or sullage. Grease traps shall be designed in such a way that solidified grease and fats aretrapped in a chamber prior to discharge and may be skimmed off by means of aperforated strainer or bucket. The trap shall be sized adequately to contain the volume of liquid to be dischargedfrom the drain line and the accumulated grease.

2.6 Concrete and Reinforcement Requirements

Unless otherwise specified in other sections of this guidelines, all the concrete andreinforcement designed for pump stations and sewer networks shall comply withthe following subsections.



2.6.1 Concrete

i. Structural use of concrete shall be designed in accordance with MS 1195

ii. Concrete shall generally comply with the relevant requirements in MS 523

iii. Concrete for purposes other than manholes and pumping stations shall havea strength grade not less than Grade C20 where unreinforced, and not lessthan Grade C30 where reinforced

iv. Structures that are designed for retaining sewage or other aqueous liquidsshall be in accordance with BS8007, which specifies C35A concrete.Where required, higher strength grades may be specified by the DirectorGeneral.

v. Concrete exposed to a sewage atmosphere shall be lined with minimum 20mm high alumina cement mortar complying with BS 915 Part 2 or 2 mmepoxy coating using a method of application approved by the Commission.

vi. Concrete and cement mortar shall be made using a cement with sufficientresistance to sulphate attack if contacted with sewage

vii. Approval for admixtures shall be obtained prior to inclusion in the concretemix. All admixtures shall comply with MS 922

Aggregates shall comply with MS 29 and shall be coarse aggregate of maximum 20mm nominal size

2.6.2 Cement

One of the following cement shall be used to resist sulphate attack:

♦ Sulphate-resisting Portland cement complying with MS 1037

♦ Portland pulverised fuel ash cement complying with MS 1227

♦ Portland blastfurnace cement complying with MS 1389

♦ High silica content Portland cement complying with AS/NZS 3582

♦ Super-sulphated cement complying with BS 4248

2.6.3 Steel Reinforcement and Falsework

♦ Steel reinforcement shall comply with:

1. MS 144 for cold reduced mild steel wire

2. MS 145 for steel fabric

3. MS 146 for hot rolled steel bars

♦ Scheduling, dimensioning, bending and cutting of steel reinforcement shallbe in accordance with BS 8666

♦ Welding of steel reinforcement shall be in accordance with BS 7123

♦ Falsework shall be in accordance with BS 5975


58 (this page is intended to be blank) Volume 3 Malaysian SewerageIndustry Guidelines

Section 3

Construction andInstallation

Construction and Installation


3.1 Introduction

The correct installation of sewer systems is critical to the efficient and effectivesewer system operation. Poor construction practice causes defects in the sewer atjoints, along pipe barrels, at manholes, transition points (e.g. pipe to manhole), etc.Adequate site supervision and certification by consultants, with reference toapproved design drawings, are therefore also required.

The various construction and installation aspects of sewer system can be dividedinto:

i. Pipes and Fittings Delivery and Handling

ii. Trench Excavation

iii. Pipe Laying

iv. Pipe Jointing

v. Special Requirements for Ancillaries and Protection

vi. Connections to Public Sewers

A description of the requirements for each stage is given below.

3.2 Pipes and Fittings Delivery and Handling

3.2.1 Pipes and Fittings Delivery

a) Materials delivered shall be from approved suppliers.

b) Pipes and fittings on the delivery truck shall be secured firmly withoutdamaging the pipe and fittings. Pipes and fittings shall be protected fromany damage from the chain securings by using rubber, carpet or textilepaddings.

c) Pipes and fittings shall be checked to ensure that they have not movedduring transportation.

d) The pipes and fittings shall not be stacked in contact with each other andshall be separated by wooden spacers. The pipes stack can be secured bystrapping or crating or can be secured by chocks at the outer pipes of eachlayer.

e) Sockets of pipe in adjacent layers should be placed at opposite ends.Alternatively, sockets of adjacent pipe can be placed at opposite ends.

f) Thermoplastic pipes (PE, ABS) shall not be supported in such a way thatwill cause the pipes to be twisted or bowed.

g) Sewer pipe and components shall be checked for damage before beingremoved from the delivery truck



h) The delivered pipes and fittings shall be checked against the designdrawings and the delivery docket to ensure the pipe and fittings deliveredare of the strength, stiffness, pressure class, length, joint type, diameter,fitting type, etc. specified.

i) The delivery truck shall be positioned on a flat ground or in such a waythat pipes and fittings would not fall off the truck when unsecuring thefastenings.

j) Pipes and fittings shall not be pushed off the delivery truck and shall notbe allowed to drop to the ground.

k) When pipes are delivered in crates, the crates shall be removed intact,wherever possible.

l) Pipes and fittings shall be lifted from the delivery truck using approvedslings. Plastic covered wire mesh slings, hemp rope slings and chainslings without rubber sleeving are not suitable. For plastic pipes or pipeswith external coating, webbed synthetic slings shall be used.

m) Alternatively, pipes and fittings can be removed from the delivery truck byrolling a pipe at a time down the wooden runners. The pipe rolling shallbe simultaneously controlled by ropes.

n) Uncrated light thermoplastic pipes shall be lifted manually and carefullyoff the truck and shall not be dragged across the truck bed, edges or otherhard and sharp surfaces. This is to avoid the scoring of plastic pipe.

3.2.2 Pipe Handling at Site

a) Pipes shall not be dragged or pushed over the ground.

b) Pipes and fittings shall not be dropped in any way.

c) Pipes and fittings shall not knock against each other or any other objects.

d) The pipe lifting shall be controlled, where necessary, using ropes or byhand to ensure they do not knock against other objects.

e) When rolled, pipes shall be rolled on smooth timber bearers, which are freeof nails, fasteners, etc., and sufficiently raised above the ground to preventhitting any rocky ground, tree roots, etc.

f) When rolled on timbers, pipes shall not be pushed with a machinerybucket.

g) Pipes with external coatings shall not be rolled. Instead, these pipe shallbe lifted into place.

h) Pipes and fittings shall be lifted using approved slings

i) Pipe lifting equipment shall be of sufficient strength and reach to lift theintended individual pipe or crate of pipes.

j) Mechanical lifting units (cranes, backhoes etc.) shall be stable or properlystabilised prior to lifting operations to ensure they would not tip anddamage pipe and fittings.



k) The slings or chains used for lifting the load shall be secured to the load inthe right manner to ensure the load does not slip or tilt excessively.

l) All other safe lifting procedures not covered above shall be adopted.

m) The lifting and moving of all the steel pipes and any pipes that containinternal linings shall follow the manufacturer instructions.

3.2.3 Pipe Storage

a) The pipe and fittings storage area shall be away from traffic and shall notobstruct any property access or pedestrian route.

b) The pipe and fittings storage area shall be at a location that allows liftingmachinery to position easily and safely for lifting pipes and fittings.

c) Pipes shall be stacked on a flat and level firm ground or the base of thepipe stack shall be made level using additional solid timbers under basebearers.

d) There shall be no rocks, tree roots, etc. under the pipe stack, which maycause point load.

e) The sockets shall be alternated to different ends for each pipe stack layer.The sockets shall be protruded out of the stack.

f) The base timber bearers shall be sound and without protrusions. The crosssection of each timber shall be at least 75 mm by 75 mm. The base bearersshall provide support near the pipe ends, but placed behind sockets. Theplacement of base bears shall not be more than 1.5 m apart.

g) VC, RC, DI, Steel and GRP pipe layers shall be separated using timberspacers of at least 50 mm wide and 50 mm thick. These spacers shall notbe placed more than 1.5 m apart. These spacers will prevent pipes in eachlayer from touching pipes in the next layer.

h) For VC and RC pipes that are not crated, the pipes shall not be stackedmore than 3 pipes high. The pipe stacks shall be wedged to prevent themfrom rolling off the stack.

i) Thermoplastic pipes (PE and ABS) shall be stacked in such a way toprevent them from being twisted or bowed.

j) Thermoplastic pipes shall be either stacked in a pyramid with no more than1 m high or in a square with vertical side supports for more than 2 pipeshigh.

k) Plastic pipe and fittings shall be kept under a cover that prevents directexposure to sun light.

l) Plastic pipe and fittings shall not be covered with plastic sheeting.

m) Plastic pipe and fittings shall be stored away from oils, greases, solventsand other aggressive chemicals.

n) Plastic pipe shall be stored away from sources of heat such as engineexhausts.

o) Care shall be taken to prevent scoring and scratching of plastic pipe andfittings.



p) Joint lubricants, rubber rings and other jointing materials shall be stored ina secured area that cannot be accessed by the public.

q) Any safe pipe stacking procedure not covered above, but recommended bythe manufacturer, shall be adopted.

r) The rubber rings that are not delivered fitted to the pipe socket or sleeveshall be stored away from direct sunlight or continual artificial light. Also,the rubber rings shall be stored in a cool area that is away from oils,greases or other petroleum products.

s) When rubber rings are delivered fitted to a pipe socket or sleeve, the pipeends with the rubber ring shall be shielded from sunlight using a hessiancloth.

t) Rubber rings shall be retained in the original sealed packaging until theyare required.

3.2.4 Pipe Damage

a) Pipes, fittings (including coatings and linings) and rubber rings shall beinspected for damage on delivery, immediately before laying and afterlaying.

b) Damaged pipe and fittings shall be identified and marked with an indeliblemarking of “Damaged” in a clearly distinguishable colour.

c) Damaged rubber rings shall be cut through completely to preventinadvertent use.

d) Damaged pipe, fittings, and rubber rings shall be set aside and separatedfrom the undamaged components.

e) Pipes or fittings shall only be repaired if they can be restored back to asatisfactory state. Approval for repair shall be sought from theCommission before the repair.

f) Pipes or fittings that are damaged and are in a repairable state shall berepaired according to the manufacturers instructions.

g) Damaged pipe and fittings that are not permitted to be repaired shall beremoved from the site as soon as possible.

h) PE and ABS pipes with damage in the barrel, shall have the damagedsection and at least 100 mm either side of the damage cut from the barrel.

i) Repaired pipes and fittings shall be used only after the approval for reusefrom the Commission is granted.



3.3 Trench Excavation

3.3.1 Protection of Affected Services, Structures, Pavements andVegetation

a) Owners of affected property, structures, services and other pipelines(sewer, water, gas, electricity, telecommunications lines, fuel lines,chemical pipelines) along or within 3 m of the excavation shall be notified.

b) Services and other pipelines shall be protected, uncovered, temporarilysupported or temporarily relocated in accordance with the conditionsspecified by the owner.

c) Where the shutdown of a service or pipeline cannot be avoided,arrangements shall be made with the owner of the service or the pipelineon the closure and reinstatement requirements.

d) Damages to any affected structure, service or pipeline shall be avoided.

e) Damage to any structure, service or pipeline shall be informed to theowner and shall be repaired as quickly as possible in accordance with therequirements of the owner.

f) Damage to vegetation (trees, bushes, gardens), paved areas (roads,footways, kerbs), fences or other property within the construction zoneshall be minimised.

g) The length of time that any paved route is out of use shall be minimised.

h) Not more than half the width of a roadway shall be disrupted at any onetime.

i) Spoils shall not be placed on road surfaces. Where there is no otherapproved storage area, spoil shall be carted away.

j) Non-reusable material excavated from roadways shall be disposed of in anappropriate manner. Only fillings approved by the responsible authorityfor the roads shall be used as refill.

k) Excavations shall be sufficiently clear of building foundations.

l) Excavations adjacent to roads shall be at least 1 m clear of the road edgeexcept when otherwise approved by the Director General.

m) Trenches adjacent to roads, buildings and structures shall be continuouslysupported until the trench is refilled.

n) Structures, services, vegetation, paving, or other property not within theconstruction zone shall not be damaged.

o) Temporary fencing shall be provided where barriers such as fences andwalls are dismantled.

p) Warning signs and temporary fencing shall be provided at the work site forexcavation spoils, access routes, steep or loose slopes resulted byexcavation work.



q) Warning signs shall be in accordance with the relevant MalaysianStandards. Some of the relevant Malaysian Standards are:

i. MS 980 Specification for safety signs and colours: colorimetricand photometric properties of materials

ii. MS 981 Specification for safety signs and colour: colour anddesign

iii. MS 982 Specification for safety signs, notices and graphicsymbols

r) Adequate lighting and reflective signals, which can make clearly visiblethe perimeter of the work site to pedestrians and traffic, shall be provided.

s) Adequate lighting shall be provided for works undertaken in poor lightingor at night. Lighting in confined spaces shall be explosion proof.

t) Alternative means of access shall be provided to rights of way, buildingsand property where usual means of access are disrupted by the excavation.

u) Soils shall not be taken out of the work site, put onto pavements or flusheddown to drains or water courses.

v) Road drains, gutters and channels shall not be obstructed.

w) Drains disturbed by works shall be rerouted to ensure continual operation.

x) Sufficient top soil that will be used for surface reinstatement shall beremoved and stockpiled separately.

y) When dewatering, care shall be taken to ensure that the adjacent structures,services and building foundations are not affected.

z) Water removed from the excavation shall be disposed of without damagingother property or causing a public nuisance.

3.3.2 Excavation Requirements

a) The required line of the sewer and manhole locations shall be set out usingaccepted surveying practices.

b) Manhole locations shall be pegged and the line of the excavation betweenmanholes shall be maintained straight using one or more of pegs, chalk lineslaser beam lines and string line.

c) Changes to the line, grade or level due to unforeseen obstructions orproximity to services shall be approved by the Commission prior to makingthe actual changes.

d) The trench shall be excavated precisely along the marked alignment toensure the sewer will be in the centre of the trench.

e) The trench shall be excavated to a depth so that the sewer can achieve thespecified level and grade when the specified bedding depth is used.

f) Over-excavation of the trench depth shall be avoided.



g) For open excavation, depending on depth of sewer and soil condition,sufficient slope protection must be provided and supported by approvedconsultant drawings and design.

h) When the excavations are required to cross rivers, railway lines, and anyother obstructions, minimum soil cover requirements specified by theresponsible authorities shall be observed. In extreme cases, inverted siphonsmay be necessary. Minimum requirements for inverted siphons are shown inthe standard drawings in the Appendix, and they must be designedindividually based on actual locations.

i) When working with poor ground conditions, construction depth shall beminimised. Reference shall be made to the approved longitudinal and cross-sectional sewer profile drawings, which give details of construction basedon soil reports.

j) The base of the trench shall be trimmed carefully to level and grade.

k) Where sight rails are used to determine trench excavation depth, at leastthree sight rails shall be used for each manhole length.

l) Sight rails shall be fixed to a uniform height above sewer invert.

m) Rocks that cause an uneven trench base shall be removed. The resultingholes shall be refilled with the specified embedment material.

n) The trench in the pipe zone shall be excavated to the minimum width limitsas given in the specification, except where a wider trench is needed due tounsupportive soil adjacent to the pipe zone.

o) The trench sides shall be vertical except where permitted otherwise by theCommission.

p) To prevent trench wall from collapsing which may lead to injuries and pipedamage, timber or steel support shall be provided in the trench when thetrench is deeper than 1.5 m. These supports must be adequately designedfor.

q) Where possible, spoil shall be placed only on one side of the trench.

r) Spoil shall be placed at an appropriate distance away from the edge of thetrench (minimum 600 mm). This is to prevent the spoil material fromfalling into the trench or to prevent the weight of the spoil from collapsingthe trench wall.

s) Unsupportive (very soft, loose, spongy or puddly) soil in the base of thetrench (as determined by the Commission) shall be removed and replaced.The replacement based shall be sufficiently supportive and shall requireapproval from the Commission.

t) Excessive excavation shall be refilled with approved materials to thespecified compaction.

u) Where possible, the excavated trench shall be kept free of water untilsufficient backfill is placed above the sewer. This is to prevent the base ofthe trench from becoming spongy and to prevent the pipe from moving offline or grade.



v) Changes to the line, grade or level of the sewer shall be properly recordedfor incorporation in the as-constructed drawings. All as-constructeddrawings, irrespective of whether there are changes to the original designdrawings, shall be certified by consultants and shall include sufficientdetails, including as-built sewer invert levels. These drawings shall besubmitted to the Director General.

w) Excavation shall not proceed too far ahead of pipe laying to avoid damagesfrom flooding or spoil.

x) Excavation shall not proceed too far ahead of the required trench supportplacing to avoid trench wall from collapsing.

y) Excavation shall comply with the relevant Occupational Safety and HealthAct (OSHA) requirements for safety.

3.3.3 Bored Excavation

a) The bore shall be on the line, level and grade and of sufficient diameter toallow pipes to be inserted without over-stressing the joints or damaging thepipes.

3.4 Pipe Laying

3.4.1 Pipe Bedding

a) Only approved materials are allowed to be used for pipe embedment. Theyshall be in accordance to the approved longitudinal and cross-sectionalsewer profile drawings, which shall also provide details of the designedbedding types.

b) The bedding material shall be placed as soon as possible after the base ofthe trench is prepared and excess water has been removed.

c) Granular bedding shall be placed, compacted and graded so that it offerscontinuous support to the sewer. The compacting, where required, shallachieve a uniform density.

d) A small hole shall be left in granular bedding for each socket, jointingsleeve, flange, etc. that may project into the bedding. The holes shall be ofsize that is just sufficient for projections to be clear of bedding. Long andlarge holes that may undermine the pipe barrel support are not allowed.

e) A recess shall be made in the bedding to permit the withdrawal of the slingwithout disturbing the remaining bedding.

f) Where the bedding is disturbed, the pipe shall be raised again to repair thebedding.

g) Pegs or other temporary aids to levelling shall be removed before pipelaying.



3.4.2 Pipe and Fittings Placement

a) Before lowering the pipes into the trench, pipes shall be placed next to thetrench away from the trench edge. The pipes shall be placed on the oppositeside of the spoil beside the trench with their sockets facing upstream.Where required, the pipes shall be blocked or chocked to prevent anyrolling.

b) Pipes and fittings (including linings, sheathings and protective paintworks)shall be checked for damage before and after laying in the trench.

c) VC pipes shall be carefully tapped at mid length and either end with awooden mallet or, otherwise, a metal bar. This is to detect a clear ring thatindicates soundness. This is best undertaken while each pipe is lifted in freeair with a lifting sling.

d) Pipe and fittings shall not be dropped into the trench. Instead, pipes shall belowered into the trench using approved slings.

e) Pipes shall be laid from the downstream end towards the upstream end.

f) The laying of pipes shall proceed carefully to ensure the line, level andgrade are within the specified tolerances.

g) Pipes shall not be dropped or impacted forcefully into the bedding to obtainthe specified level or grade.

h) Concrete pipes with elliptical reinforcement shall be laid with the load lineon the vertical axis at the top or bottom position.

i) Holes made in granular bedding for projections of sockets, flanges, etc. shallbe lightly filled where necessary without pushing the pipe/fitting off line,level or grade.

j) Bedding shall be checked to ensure continuous support along the pipebarrel. Further bedding material shall be placed to an even height anduniformly compacted across the trench to ensure the full support of the pipehaunch.

k) Pipes that are laid on concrete, grout, cement stabilised bedding orconnected to a concrete structure shall consist of a flexible joint at theupstream end immediately outside such a zone.

l) Pipe level, grade and alignment shall be sighted using sight rails and boningrod or laser and target. They shall be in accordance to the approvedlongitudinal and cross-sectional sewer profile drawings, which shall besubmitted for approval before work at site is allowed to begin.

m) The invert level of each pipe laid shall be checked during laying andimmediately after laying completion, and with reference to the approveddrawings.

n) Boning rods shall have a foot to rest on the pipe invert with a vertical spiritlevel attached and shall not be more than 45 m apart.

o) The pipe interior shall be cleaned after laying and kept clean and free ofwater.

p) The pipe ends shall be sealed with a tightly fitting plug immediately afterlaying, cleaning of the pipe interior and at the end of the day after laying.



q) The branch arm of the oblique branch junction fitting, if installed, shall belaid in such a way that it is at approximately 45° off horizontal level.

r) Junction fittings shall be properly supported using well compacted crushedrock (or, where required, concrete). The coverage of the support shall beacross to the trench wall and into the junction trench.

s) Branch connections shall be sealed with an approved plug whereconnections are to be made at a later time.

t) Any pipe laid that is out of alignment either vertically or horizontally orshows undue settlement shall be taken up and re-laid correctly.

u) Photographs shall be taken during pipe laying and after sewer pipe layingfor all lengths of pipes and manholes.

3.4.3 Pipe Jacking

a) Jacking method of pipe laying shall be employed only when the conditionsor the requirements of the responsible authorities require such a method.

b) The pipes used for jacking shall be able to withstand the laterally inducedjacking stresses without damage.

c) The setting out of the guide rails for the pipe and the actual jackingoperation shall maintain a high accuracy level of line and grade.

d) The direction and grade for jacked sewer shall not deviate from the designedalignment for more than 100 mm for every 100 meters of sewer.

e) All the joints used for connecting the jacked pipes shall be watertight anddurable.

3.4.4 Concrete Pipe Support

a) Concrete used shall be 20 MPa Portland cement concrete with a slump nogreater than 80 mm.

b) When purpose-made pre-cast concrete blocks are used, the block shall haveapproximately the same width as the trench and shall be positioned justbehind each pipe socket. A compressible packer of polystyrene or particleboard shall be placed between the pipe and the concrete block.

c) Concrete shall be poured in one lift.

d) Pipes shall be prevented from floating or other movement during concretepouring.

e) A space shall be left between the concrete supports for the pipe socket byuse of a polystyrene spacer of 20 mm minimum thickness. This is to retainrotational flexibility at the joint.

f) The concrete support shall fit the pipe closely after hardening.

g) Concrete shall be allowed to cure for at least 7 days before applying anyload.

h) Where the trench base is soft or puddly, a blinding layer shall be placed onthe trench base before the concrete is placed.



3.4.5 Pipe Cutting

a) Only VC, HDPE, ABS and DI pipes are permitted to be cut in the field.However prior approval from the Director General is required should theHDPE helically wound profile wall pipe needs to be cut in the field. Allpipes shall be cut in accordance to approved methods.

b) Rough edges and burrs shall be removed from inside and outside of HDPEand ABS pipe with a rasp or file.

c) Pipes shall be cut in a neat and skilful manner by workers experienced inpipe cutting.

d) Pipes shall be cut perpendicularly to the pipe axis.

e) Any damage to the cement lining of DI pipe shall be repaired to thesatisfaction of the Commission.

3.4.6 Backfill of Trench

a) Selected excavated material shall be placed above the specified pipe supportuntil 300 mm above the sewer. They shall be in accordance to the approvedlongitudinal and cross-sectional sewer profile drawings, which also give thebedding details and the types of fill material.

b) Trench support shall be progressively removed as the backfill is placed.

c) There shall be at least 300 mm of cover over the sewer before lightmechanical compaction can commence.

d) There shall be at least 1000 mm of cover over the sewer before heavymechanical compaction can commence.

e) For plastic pipe, a metallic marker tape shall be laid along the line of thesewer at approximately 500 mm below the surface level.

3.4.6 Other General Requirements

a) Reference shall be made to the approved longitudinal and cross-sectionaldrawings of sewer profiles of both gravity sewers and force mains. Thesedrawings submitted for approval must include details of bedding types andmanhole types, and their design must be must be supported by soil reports.

b) Pipe laying shall be such that there is adequate access for operations andmaintenance of completed sewers, especially in undulating ground profiles,with a minimum width of 6 metres, which shall be supported by drawingswith ground profiles during drawings approval stage.

c) For easy identification of underground forced sewer mains, their layoutshall be planted with marker posts at every 200m length and at everychange of pipe directions. Valve chambers provided shall have adequateaccess for operations and maintenance.



d) There shall be adequate site supervision of construction, and at least thesedocuments must be submitted before approval of construction:

i. Photographs showing sewer pipe laying during an after constructionfor all lengths.

ii. Testing certificates from the consultants (see Section 4 on SewerTesting)

iii. Supervision certification from the consultantsiv. As-built drawings certified by the consultants

e) The construction and installation works shall incorporate the considerationof health and safety.

3.5 Pipe Jointing

3.5.1 Flexible Joints

a) Joint components (i.e. spigots and sockets or sleeves and rubber seals) shallbe checked for damage after delivery, before and after usage.

b) Every part of the rubber ring shall be bent by hand to detect cracks.

c) VC pipe sockets shall be gently tapped with a wooden mallet or, otherwise,a metal bar to detect a clear ring that indicates soundness.

d) Steel sleeve collars used for jacking pipe shall be checked for damage to thecoating.

e) Pipe jointing surfaces and rubber seals shall be wiped clean immediatelybefore jointing using a clean cloth.

f) The rubber ring shall be placed correctly around the pipe joint.

g) The rubber ring shall not be twisted in any way prior to jointing and shall beseated in the correct position.

h) For skid type of joints (i.e. the sealing ring remains stationary and does notroll into place), the spigot shall be lubricated with an approved lubricant.

i) The pipe to be jointed shall be aligned with the laid sewer before pushing inthe joint.

j) The pipe to be laid shall be orientated so that the offset inside the pipe at thejoint is minimise at the invert.

k) The pipe that is already laid and to be connected to another pipe shall berestrained to prevent its pipe joints being further stressed and to prevent thelaid pipe from being pushed off grade or alignment.

l) Pipe joints shall be connected using a bar and block (crow bar and a blockof wood to protect the pipe end) or a pipe puller.

m) A machine bucket shall only be used to connect a pipe joint where approvalis given by the Commission. This method shall only be used for largediameter pipes (larger than 600 diameter pipe) where the jointingcompression force makes it impossible to use a bar and block or pipe puller.A timber shall be placed across the pipe end to protect the pipe from



damage. Pressure shall be applied by the bucket gently while the insertionshall be carefully monitored and directed by a person next to the joint.

n) No excessive force shall be applied to make the joint.

o) After pushing the spigot into the socket, the seal shall be checked to ensurethe seal is correctly located and the spigot is properly inserted. Nocontaminants are allowed between jointing surfaces. The joint or pipe shallnot have damage from jointing.

p) Any allowable deflections at joints shall only be made after the pipe jointingis made.

q) Where a pipe is to be deflected at a joint, the deflection shall not exceed theallowable limit for the specific type of joint.

3.5.2 Solvent Weld Joints

a) The socket and spigot shall be checked for damage before and after jointing.

b) Damaged spigot ends shall be cut from the pipe with 100 mm clearance tothe damage. The spigot end shall be cut perpendicularly to the pipe and anyburrs shall be removed.

c) The spigot shall be inserted up to the witness mark.

d) If a witness mark is not already on the pipe, the mark shall be made toensure that the spigot is inserted to the appropriate length.

e) Witness marks drawn on site shall be made with a soft pencil or felt penmarker that would not score or scratch the pipe.

f) The witness mark shall be of the depth of the socket and shall be measuredfrom the pipe end.

g) A dry fit of the joint shall be made before the jointing.

h) Jointing surfaces shall be wiped clean and dried with a clean cloth.

i) Jointing surfaces shall be primed using an approved priming solution. Thepriming shall be applied with a clean cloth or swab freshly dipped in thefluid immediately before jointing.

j) A thin and even coat of solvent cement shall be applied to the socket and thespigot, which should then be inserted up to the witness mark.

k) The jointing surfaces shall not be contaminated with water, dirt, etc.

l) The jointing shall be made immediately after the application of solventcement.

m) After the spigot is pushed firmly into the socket, the joint shall be hold inthe same position for at least 30 seconds without moving.

n) The jointed pipes shall not be moved for at least 5 minutes after jointing.The jointed pipes shall be handled with extreme care for at least anotherhour.

o) Joints shall be left to dry for at least 24 hours before pressure testing.



p) Containers of solvent cement and primer shall be kept tightly sealed whennot in use.

q) Solvent cement and priming fluid are highly flammable. Therefore, thesolutions shall be stored in a cool place away from any source of spark orfire.

3.5.3 Flanged Joints

a) Flanges, particularly flange faces and rubber seal shall be checked fordamage before and after jointing.

b) Appropriate metal backing plates shall be used on plastic flanged pipe.

c) Screwed-on flanges shall have the screw thread sealed with a compoundsuitable for sewers.

d) Flanged ends shall be correctly aligned before jointing.

e) A steel bar or similar object shall not be used as a lever through the flangeholes to bring the bolt holes into line prior to bolting.

f) The rubber seal between flanges shall be made of an approved compoundand shall meet the specified requirements.

g) The flange faces and the rubber seal shall be wiped clean with a clothimmediately before jointing.

h) Bolts shall be tightened evenly and gradually in rotation.

i) Bolts and nuts shall be tightened with a torque trench set at an appropriatetorque.

j) Plastic flanges shall not be distorted before or after jointing.

k) After pressure testing, metal flanges shall be reprimed and painted with twocoats of bituminous based coating in accordance with BS 4147 for belowground protection.

3.5.4 Steel Pipe Welded Joints (Field Welding)

a) The welded joint shall use a socket-spigot joint with taper sleeve whereverpossible.

b) Welding surfaces shall be cleaned to a bright metallic finish before welding.

c) Welders shall be qualified in accordance with the requirements of BritishStandard BS 4515 Specification for welding of steel pipelines on land andoffshore.

d) Welding procedures shall be tested, qualified and approved in accordancewith BS 4515.

e) Welds shall be inspected and tested in accordance with BS 4515.

f) After welding, exposed external surfaces shall be cleaned by sand blastingor wire brushing. The dry surfaces shall be wrapped in an approved mannerwith an approved wrapping tape to provide corrosion resistance.



3.5.5 Polyethylene Butt Welded Joints

a) The pipes to be joined shall be of the same grade of polyethylene and of thesame wall thickness.

b) The butt welding machine shall be of an approved type and shall be fit foruse.

c) The welding machine shall be sheltered from wind and rain during thewelding process.

d) A practice weld shall be performed and discarded to check the operationaleffectiveness of the machine.

e) The pipe ends shall be trimmed square.

f) The ends to be jointed shall be kept free of dirt, grease and moisture aftertrimming.

g) The heating plate shall be brought into contact with the pipe ends only afterit is at the correct temperature.

h) The pipe ends shall be held against the heating plate for the specified timeappropriate for that pipe size.

i) Immediately after the removal of the heating plate (no longer than 15seconds after heating), the pipe ends shall be pressed together with anappropriate pressure for a specified time appropriate for that pipe size.

j) The joint shall be maintained clamped and pressurised in the machine for asuitable period of cooling time (approx. 10 minutes minimum).

k) After removed from the machine, the joint shall not be stressed until it hascompletely cooled (approx. 10 minutes minimum).

l) The weld shall not be artificially cooled with cold air or water.

m) The external bead shall carefully be removed. The joint zone shall bethoroughly checked.

n) A pipe end that has undergone a complete heating cycle but not joined shallnot be reheated. The unjoined pipe end shall be cut off to at least 250 mmfrom the end.

3.6 Special Requirements For Sewer

3.6.1 Thrust Blocks for Pressure Pipelines

a) The thrust block shall be extended to approximately 180° around the fitting.

b) The thrust block shall not cover a flexible joint.

c) The thrust block shall be constructed equally around the centreline of thefitting.

d) The thrust block shall bear firmly against a recess at the side of the trench.

e) The trench face which the thrust block bears against shall be freshly cut andundisturbed.



f) Each thrust block shall have sufficient bearing area.

g) Thrust block shall be cast-in-place with 20 MPa concrete.

h) For plastic pipe or pipe with a protective coating, a compressible membraneof rubber, felt or cork shall be placed on the pipe to protect it from damagefrom its movement in the thrust block.

i) Formwork shall be used to cast the thrust block to the required dimensions.

j) Formwork shall be removed before any testing.

k) Reference shall made to the standard drawings for thrust block to ensureproper shape and size, which must be designed for each individual thrustblocks.

3.6.2 Pipe Restraints and Bulkheads on Steep Slopes

a) A bulkhead to prevent soil erosion shall be used where the gradient of thesewer is steeper than 1 in 40.

b) A restraint to prevent sewer slippage shall be used where the gradient of thesewer is steeper than 1 in 6.

c) The restraint or bulkhead shall be placed at the downstream side of thesocket.

d) Concrete bulkheads shall be keyed into the base and sides of the trench by atleast 100 mm.

e) A weep hole with the upstream end covered with a geotextile filter shall beprovided through a bulkhead immediately above pipe invert to allowdrainage of groundwater.

3.6.3 Pipe Embedment and Overlay

a) The embedment material type and its grading shall take considerations ofthe sewer type or length.

b) Reference shall be made to the approved longitudinal and cross-sectionaldrawings of the sewers showing the bedding types, which shall be designedbased on supporting soil reports.

c) Embedment material shall not be contaminated with other soils.

d) Embedment material shall be brought up evenly in layers on each side of thepipe.

e) Each embedment layer shall be placed to a depth that permits thecompaction equipment to achieve the specified density.

f) The pipe shall not be pushed off alignment, level or grade while placing theembedment.

g) Where the embedment requires tamping, tamping equipment shall not comeinto contact with the pipe.

h) Temporary trench wall support shall be lifted when the embedment iscompacted.



i) While placing the embedment for the pipe haunches, unnecessarily voidedareas shall be avoided.

j) At least 300 mm of cover shall be placed over the pipe before lightmechanical compaction, such as a hand operated whacker, can commence.

3.6.4 Sleeving of Ductile Iron Pipe

a) Plastic sleeve shall be secured immediately behind the second spigotjointing witness mark with three overlapping turns of adhesive tape. Afterthat, sleeve shall be tightly wrapped around the pipe by folding over surplussleeving. Then, the sleeving shall be further secured with three winds ofoverlapping adhesive tape at one meter intervals.

b) The pipe shall be placed in the trench with the folding of the sleeve locatedat the top of the pipe.

c) After the pipe jointing, the sleeve of the preceding pipe shall be broughtover to cover the socket and the cover shall follow the socket outer surfaceclosely.

d) The sleeve of the preceding pipe shall overlap the sleeve of the next pipe.The sleeve overlap shall be secured with three overlapping winds of tape.

3.6.5 ‘Rocker’ Pipe Connections to Manholes

a) The ‘rocker’ pipe connecting sewers to manholes shall have sufficient castinsitu concrete surround and extended concrete base as shown in typicalmanholes drawings in Appendix A.

3.7 Reinstatement

a) All structures, services, fences, drains, gardens, improved surfaces, etc.disturbed by the construction shall be restored within 7 days afterbackfilling. The restored conditions shall be as similar as possible to theiroriginal condition. Also, the condition shall be to the satisfaction of theCommission, other responsible authorities and property owners.

b) Where a structure or service is affected by construction, the trench fill shallbe compacted to the equivalent of that under a pavement.

c) Within 7 days after backfilling, fill over unimproved surfaces shall beplaced to a height that will make the filled surface level and the adjacentundisturbed surfaces closely matching after settlement. All contours shallbe similar to the original condition.

d) Unimproved surfaces shall be levelled and settled to as near as possible totheir original condition in 30 to 40 days after backfill.

e) Road pavements and access ways shall be temporarily restored to a safecondition, immediately after completion of backfilling. Then, thepavements shall be permanently restored to as similar as possible to theiroriginal condition within a time frame specified by the responsibleauthority.



f) Extra excavated material, un-reusable excavated material and all rubbishshall be removed from the site and legally disposed of.

3.8 Connections to Public Sewers

3.8.1 General

Severe maintenance problems are often caused by poorly made connections tosewers. These may lead to blockages or failure of the sewer structurally. Thefollowing procedures and formalities must be followed to ensure integrity of thesewerage system.

a) The owner must seek the approval of the Director General for anyconnections that involve physical work to an existing public sewer. Theinitial notification must be made on the appropriate form.

b) Once approved, the owner may make the connection only if his contractor islicensed by the Commission for this category of work.

c) The type and location of connections shall be determined by theCommission. The type of connection could be a connection to a manhole ora connection to a sewer through junction or saddle fittings.

d) The cost of the work in making the connection shall be borne by the owner,regardless of whether the work is undertaken by his licensed contractor or alicensed contractor employed by Services Licensee.

e) The connection must be correctly made by the licensed contractor under thesupervision of an authorised inspection person.

f) When the connection is ready for inspection, the owner must notify theCommission on the appropriate form. At the same time, he must give acopy of the notice to the authorised inspection person who will makearrangements for the inspection.

g) The connection must be completely watertight to prevent infiltration. Anyevidence of infiltration in the connection pipe shall be referred to the LocalAuthority who may withhold issuing the Certificate of Fitness.

h) For a development which contains several connections from individualpremises to the proposed public sewers within the development, theconnections may be deemed covered by the original technical proposals.These individual connections will be inspected as part of the routineinspection by the authorised inspection person.

i) The inspection by the authorised inspection person for the connections toexisting public sewers shall be subjected to a standard inspection fee.

j) The design and installations shall incorporate the considerations of healthand safety

k) The difference between each premise platform level and the nearest publicsewer invert level shall not be less than 1.2 metres to avoid flooding ofpremises.



3.8.2 Junction Connections

Where an existing public sewer is circular and is of diameter DN 450 or less, anyconnection to that sewer may be made using a Y junction fitting.

Where the location of future connections are known, Y Junction fittings and theaccompanying junction connection pipework may be installed at the time of thepublic sewer construction.

The typical connection configuration of junction is shown in Figures A.11 andA.12 of Appendix A.

Where no junction pipework exists, a Y junction fitting may be installed byremoving part of the existing sewer. The connection of such a junction shall useflexible couplings.

3.8.3 Saddle Connections

Saddle connections may only be permitted where the existing sewer is at least twopipe sizes greater than the proposed connection pipe. Only saddles specificallydesigned for the type and size of the sewer to be connected to shall be used. Also,the saddle used shall be approved by the Commission.

Making a saddle connection is a highly skilled operation. Hence, only licensedcontractors who can demonstrate suitable qualifications and experience arepermitted to make this form of connection.

The saddle must be purpose-made by off-site manufacture except when the existingpipe size is 900 mm in diameter or greater, which other forms of connection arepreferred.

The saddles for concrete or vitrified clay sewers shall be bedded on cement mortar(mix 3:1) with a depth not less than 40 mm below the base of the saddle. Aflexible joint shall be provided between the saddle and the remaining connectionpipe.

The hole prepared for the saddle connection on the existing sewer shall not haveany rough edges that might cause blockage. The location of the hole on the pipeshall be at a 45° to 60° angle to the horizontal. The hole shall be made at themiddle of the pipe to avoid damages or excessive loading to the existing sewer pipejoints. The existing pipe may require extra strengthening by additional concretesurround to withstand the extra load from the connection pipe and fittings.

The connection pipe must not protrude into the existing sewer.

Any debris falling into the existing sewer during the connection shall be removed.

On completion, the saddle connection joint must be completely watertight toprevent infiltration.



3.8.4 Manhole Connections

Manholes may be constructed on the public sewer for private sewer connectionswhere:

a) good practice requires a manhole for ease of maintenance, or

b) the diameter of the connection pipe is 300 mm or greater, or

c) the public sewer is more than 4.5 m deep, or

d) the point of connection is more than 5 m from an existing or proposedmanhole.

Where site conditions prevent manhole construction on the existing public sewer,the manhole may be provided on the connection pipe as near to the public sewer aspossible.

Section 4

Sewer Testing

Sewer Testing


4.1 General

Sewers and ancillary works shall be tested and inspected for water-tightness toprevent infiltration and exfiltration and to ensure the pipe are laid correctlyaccording to the designed straightness and grade. The testing of the sewers andancillary works before backfill will facilitate the replacement of any identifiedfaulty pipes and joints. The testing of the sewers and ancillary works after backfillwill reveal the leakages caused by the displacement of joints and subsequentdamage. The testing shall be supervised by consultants and their testing certificatesissued by the consultants shall be submitted to the Commission before finalapproval.

The tests that are required to be conducted are listed as follows:

I) Before Backfill

a) Gravity Sewer:

i. Exfiltration Test (Either low pressure air or water tests)

ii. Check for straightness, obstruction and grade

b) Force Main:

i. Exfiltration Test (When required)

ii. High pressure water test

iii. High pressure leakage test (Following high pressure water test)

iv. Check for straightness, obstruction and grade

c) Manhole and others:

i. Visual inspection

ii. Water-tightness test (when required)

To prevent movement of the sewer, embedment material shall be placed aroundand over the sewer prior to testing. The section of the joints above spring line shallbe exposed.

For pipe or part that is made of material that will deteriorate under the sun, theexposed parts of the pipe shall be shielded from direct exposure to the sun duringtesting.

The concrete used for supporting the pipe or resisting thrust shall be cured for atleast seven days prior to testing.

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II) After Backfill

a) Gravity Sewer:

i) Exfiltration Test (Either low pressure air or water tests)

ii) Infiltration Test (when required)

iii) CCTV Test (when required)

Before and after any test, the sewer pipeline to be tested shall be clean, which shallbe flushed clean when necessary. Any leaks or defects identified from any testshall be located and repaired. After testing has been completed, the cleaned sewershall be plugged at open ends to prevent dirt or soil from getting into the sewer.

4.2 Testing of Gravity Sewers

The tests of gravity sewers are generally conducted to ensure there is no leaks,damages, or laying errors. An exfiltration test, which can be either a low pressure air test or a water test shallbe performed on the sewer before any concrete pipe encasement or backfill. Afterbackfilling, an exfiltration test is required again on the sewer laid. In addition, aninfiltration test shall be conducted if:

a) required by the Commission

b) detected high groundwater table

When infiltration has been confirmed by the infiltration test, light and mirrormethod or CCTV may be used to isolate the locations of leaks. If a CCTVinspection is conducted, a video and written record of the CCTV inspection shallbe provided to the Commission no later than 7 days after the inspection.

For gravity sewers, the sewer length to be tested shall be the length betweenmanholes or proposed manhole locations. The test length for water test may beshorter where the gradient is so steep as to cause too high a head at the downstreamend. The pressure head on the sewer being tested shall not be less than 2 m abovepipe crown at the upstream end and shall not be more than 7 m above pipe crown atthe downstream end.

When desired, the air and water tests may be undertaken on shorter lengths of thelaid sewer before backfill. This is to prevent any faulty joint to go unnoticed untilit is revealed by a test on the complete length, which will be more costly and timeconsuming to rectify the defects. Testing of shorter lengths may also be necessarywhere it is required to backfill the sewer to surface level quickly. This earlybackfill may be encountered when there is wet weather, traffic crossings or sitesafety requirements.

In every stage of the works, frequent tests of straightness and obstruction shall beconducted, when required, to ensure there is no line obstruction and thestraightness or grade is correct.

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4.3 Testing of Forced Mains

For pressure sewers, the normal tests during the sewer laying may include, whererequired, the low pressure air or water exfiltration tests on short individual sections.These low pressure air or water exfiltration test are conducted, when required, toensure that the joints are watertight.

As in gravity sewers, the force mains should be checked to ensure the straightnessis correct and to ensure no obstruction in the force mains. Also, force main isrequired to be tested for its mechanical stability through the high pressure watertest. Its water-tightness shall be tested through high pressure exfiltration test.Before conducting these high pressure tests, the sewer support and thrust blockshall be allowed to develop the sufficient strength. In addition, cautions shall betaken when dealing with high pressure.

Where required, a CCTV inspection should be performed on the pipeline afterbackfilling the trench. If a CCTV inspection is performed, a video and writtenrecord of the CCTV inspection shall be provided to the Commission no later than 7days after the inspection.

For the high pressure water test, the test length will depend on:

a) the length which can be isolated effectively, i.e. suitable anchorage fortemporary end closures

b) the time permitted to leave the trench open without backfill takingconsiderations of weather, safety, traffic etc.

c) the location of permanent anchorages

d) the maximum volume of water available to fill the pipeline

e) the requirement to have the pressure at the highest point not less than 0.8times the pressure at the lowest point

After taking the above considerations, initially a maximum of 300 m length of pipeshall be laid and tested to verify that pipe laying practices are to an acceptablestandard. The maximum lengths for subsequent tests may be progressivelyincreased, as determined by the authorised inspection person, but shall not exceed1500 m.

4.4 Testing of Manhole and other ancillaries

Manhole and other ancillaries shall be constructed in such a way that noappreciable amount of infiltration or exfiltration will occur. When the manhole andother ancillaries are constructed in an effective manner, visual inspection isnormally sufficient. However, manholes and other ancillaries suspected of verypoor workmanship shall be tested with exfiltration test before backfill or concretesurrounded.

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Connections between sewer and manholes shall be constructed with extended cast-in-site concrete base and surround over the top of the rocker pipe in accordance tothe standard drawing attached. Drop manholes shall be constructed in such a way that no appreciable amount ofblockage will occur with construction details as in the standard drawings whichprovide for proper pipe outlets and proper sizing of drop pipes. A visual inspection is required on all the external and internal sections of eachmanhole before backfill. Particular attention shall be given to: a) the slope of benching,

b) joints to pipes,

c) transitions at entry and exits,

d) joints in the structure

e) quality of concrete finish

f) water-tightness of manhole cover and surround.

The internal surfaces of manholes shall be inspected visually for sources ofinfiltration after backfill and stabilisation of groundwater table. Manhole coversand surrounds shall be checked for leakage of surface water.

4.5 Low Pressure Air Test

4.5.1 General

Low pressure air test is one of the two sewer exfiltration tests recommended forsewer testing. The air test is quicker to conduct than the water test. Furthermore,no large quantity of water needed to be disposed of after the test. This test providesa quick mean for checking any damage pipe or joints. Sometimes the test isconducted on a short length to prevent damage pipe or joints from passing withoutnoticed until the final sewer test, which could be more costly and time consumingto rectify. However, these tests on the shorter length should not replace the finaltest.

4.5.2 Procedure for Testing

a) Seal the open ends, including sideline ends, using approved plugs. Strut theplugs to prevent movement. Provide temporary bracing where necessary toprevent pipeline movement during testing.

(One of the end plugs will require a connection point to permit injection ofair.)

b) Connect a hand or motorised pump to the pressure injection line at the endplug. Pressurise the test length at a slow and constant rate.

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c) Use dial pressure gauges to measure pressure. Apply an air pressure of:

i. 30 kPa for vitrified clay and reinforced concrete pipelines

ii. 50 kPa for all other pipelines

(Two gauges in series shall be used so that the accuracy of one gauge canbe confirmed by the other. The dial gauges shall be able to be read to anaccuracy of ± 0.1 kPa.)

d) Wait five minutes for air pressure to stabilise due to temperature absorptioninto pipe wall and other effects. Adjust the pressure to the required testpressure during this period.

e) Check for leaks at plugs and test apparatus. Release the air pressure whereleakage occurs. Make necessary repairs and adjustments of apparatus toprevent leakages. Repressurise the sewer pipeline in accordance with thepreceding steps again.

f) Start the test and record the pressure loss for the test duration after the finalgauge adjustment to the test pressure. Conduct the test for the test durationgiven in Table 4.1.

Table 4.1 Test Duration

Pipeline Nominal Size

Test Duration (minutes)

150 2 225 4 300 6 375 8 450 11 525 14 600 17

g) Pass the test if the pressure loss over the test duration does not exceed:

i) 7 kPa for vitrified clay and reinforced concrete pipesii) 2 kPa for all other pipes

4.5.3 Procedures for Handling Air Test Failure

I) Before Backfill a) Readjust the pipe pressure to the specified test pressure and examine for

leakage by pouring a solution of soft soap and water over the exposed jointsif the test fail.

b) Repair leaks and repeat testing where leaks are found at joints.

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c) Where leaks are not found at joints, move the plug, the one that is not usedto exert air pressure, along the pipeline to isolate lengths with leakage.Uncover pipe barrels in the isolated lengths where leakage in pipe barrels issuspected. Replace leaking pipe lengths and repeat testing.

d) Conduct low pressure water testing to verify that the air test was noterroneous where the test length fails the air test but no source of leakagecan be identified.

II) After Backfilling: a) Move the plug up from the other end along the sewer pipeline to isolate the

lengths that fail the air test.

b) Exhume the failed length of pipeline and replace pipe lengths.

c) Repeat the air test.

d) Conduct water testing to check that the air test was not erroneous whenfailed lengths could not be isolated using the air test.

e) Use CCTV, when required or available, to identify the leakage if the failsection can not be isolated by the air test or water test.

4.6 Low Pressure Water Test

4.6.1 General

The low pressure water test is commonly used for checking the water-tightness ofthe joints and the integrity of the sewer pipes. Unlike the high pressure water test,this test can not be used to check the mechanical strength of the sewer pipe.Compared with low pressure air test, this test requires more time to set up the test.Also, the water used for the test require disposal in an appropriate manner.However, this test will show the location of the leaks more clearly than the lowpressure air test.

4.6.2 Procedure

a) Seal the open ends, including sideline ends, using approved plugs. Strut theplugs to prevent movement. Provide temporary bracing where necessary toprevent sewer movement during testing.

b) Establish appropriate arrangements involving a standpipe to apply the waterhead at the upstream end.

(Acceptable arrangements include:

i. temporarily fitting a 90° bend to the upstream end, which should thenbe connected with a vertical riser of straight pipe to used as astandpipe

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ii. sealing the upstream end with a plug which has a connection point fora hose, which can be connected to a tube acting as a standpipe)

d) Fill in water from the upstream end. Ensure water head is not less than 2 mabove pipe crown at the upstream end and not greater than 7 m above pipecrown at the downstream end. Shorten the test length if the sewer gradientis so steep as to cause these water head requirements not to be met.

e) Fill the sewer slowly to the required head and bleed air from behind theupstream plugs.

(Air may be released by slightly loosening the plug and pushing in a pieceof wire between the seal and the pipe.)

f) Maintain the water head for two hours. Top up the water as required.

g) Check for leakage at the plugs and the test apparatus during the pressurisingperiod and the constant pressure holding period. Release the water pressureif leakage occurs. Make the necessary repairs and adjustments beforerepressurising again.

h) Commence the test immediately after the last adjustment of water head inthe preceding two hours period.

i) Add water to maintain the starting water head every 5 minutes during thetest period of 30 minutes. Record the total amount of water required forreadjustment.

j) Pass the water test if:

i. the loss of water does not exceed 1 litre per hour per linear metre permetre internal diameter for vitrified clay and reinforced concretepipes,

ii. there is no loss of water for pipe other than vitrified clay andreinforced concrete pipe,

iii. these is no visible leakage at the joints for all pipe types.

4.6.3 Handling Water Test Failures

I) Before Backfill: a) Readjust the internal water head to the specified test head if the test section

fails the water test. Examine visually for leakage at the external surface ofjoints.

b) Uncover pipe barrels and inspect for leakage if leakage is not evident atjoints. Drain the water and move the downstream plug towards upstream,where necessary, to isolate pipe lengths that fail the water test.

c) Repair or replace pipes before repeating the low pressure water test until thesewer passes the test.

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II) After Backfill: a) Isolate pipe lengths that fail the water test by moving the downstream plug

towards the upstream end in sections when the test sewer fails the watertest. Alternatively, conduct a CCTV inspection, where required, to identifythe source of leakage if the source of leakage can not be isolated.

b) Exhume failed pipe lengths and replace.

c) Repeat test until the sewer pipeline passes the test.

4.7 High Pressure Water Test

4.7.1 General

High pressure water test is normally used for testing the pressure sewers and pipeworks within the pump station. The main aims of the test are to ensure themechanical stability of the pipe and joints to withstand the working pressure. Sincethe test is conducted under high pressure, the anchorage of the sewer is morecritical than the low pressure tests. Preferably, the test should be conducted beforebackfill. During the test, the test pumps should not be subjected to hydrostaticpressure.

4.7.2 Procedure

a) Seal the sewer pipeline ends using “test-end” units consisting of shortlengths of pipe permanently fitted with caps or valves. Connected the “test-end” units to the test pipe section using a standard coupling, which permitseasy removal of “test-end” units after testing.

(The “test-end” units should have a valve with pressure gauge to allowfilling of the test length with water or for venting air. The gauge shall be aconventional circular gauge not less than 200 mm diameter and shall beable to read to an accuracy of ± 0.01 Mpa.)

b) For sewer on level grade, fit tees along the test length, where necessary, toensure all the air can escape. Fit air valves to such tees. Remove air valvesand blank off tees after the test is applied.

c) Fit the test pressure gauge at the lowest end of the test length.

(This prevents the test pressure from exceeding the permitted maximumpressure in the test length.)

d) Place pre-constructed temporary thrust blocks behind the test end units tobrace against thrust from the test pressures.

(No temporary bracing is permitted along the sewer pipeline. All specifiedthrust blocks must be constructed and left to cure before testing.)

e) Fill the test length slowly with water through the valve at the lowest test-end unit.

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(The water shall be of fair quality and free from sediment. A firm foamswab placed ahead of the water column will improve the expulsion of air.)

f) Set all valves at high spots to vent air.

g) Close the air vents after thorough venting of all air.

h) Fill the test length with water. Leave the filled test length undisturbed for24 hours prior to testing to allow for absorption of water into the pipes and/or jointing materials.

i) Wipe the exposed fittings and joints clean and dry and check for leakageand other irregularities during this preparatory period. Check also the testpipe for any appreciable movement and disturbance of anchorages. Drainthe water and repair any damage found. Repeat the water filling again tostart the test.

j) Pump more water into the test length to raise the pressure. Raise thepressure slowly in increments of 1 bars, with pauses of one minute betweeneach increment until achieving the lower of:

i. the maximum rated pressure of the pipes laid, or

ii. 1.5 times the design operating pressure of the pipeline (includes surgeallowance)

k) Stop the test immediately should any appreciable drop in pressure be notedduring one of these pauses. Determine the cause of the pressure drop.Drain the test length where repairs are required. Start the test again afterrepairing.

l) Pass the pressure test if there is no reduction from the test pressure in thenext 10 minutes after the test pressure is achieved. Do not reduce thepressure since the high pressure leakage test should be conductedimmediately next.

4.8 High Pressure Leakage Test

4.8.1 General

High pressure leakage test normally follows the high pressure water testimmediately. This is to avoid any unnecessary pressurising and water filling, whichcould take time and is costly. The purpose of this test is to ensure the pipe andjoint will remain intact under the pressure environment.

4.8.2 Procedure

a) Conduct the test immediately after the high pressure water test. Maintainthe following test pressures (whichever is lower) for 24 hours by pumpingin make-up water if necessary:

i. the maximum rated pressure of the pipes laid, or

ii. 1.5 times the design operating pressure of the pipeline (includes surgeallowance)

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b) Measure the amount of make-up water pumped into the pipe to maintain thetest pressure.

c) Pass the test if the measured amount of make-up water does not exceed 0.1litre per millimetre of pipe diameter per kilometre of pipe per day for each 3bars of pressure applied.

d) Reset the test pressure and check all visible joints to locate leakage whenthe test length fails the test.

4.9 Test for Straightness, Obstruction, and Grade

The sewers shall be check for straightness, obstruction, and grade wheneverpossible. For gravity sewers and force mains, the grade and straightness areimportant to achieve the designed velocity. The following tests are recommendedfor testing the laid sewer: I) Test for freedom from obstruction: a) Visual inspection

b) Insertion of mandrel

c) CCTV inspection

It should be noted that the visual inspection is only for checking a short length.Sufficient light shall be provided when carrying out the inspection. For checking along sewer, insertion of a mandrel should be adopted. II) Test for grade and straightness

a) Laser beams with sighting targets

b) Sight rails and boning rods

c) CCTV inspection

d) lamp and mirrors

e) Insertion of a smooth balls

The first three methods will provide a more exact assurance for both the grade andstraightness of sewers, which shall be used whenever possible. The latter twomethods will provide a rough ideas on whether the sewers are laid graded orstraight, which should be used only for a quick check.

4.10 CCTV Inspection

The following subsections outline details on how the CCTV inspectionrequirements shall be implemented. These guidelines are also aim to enhanceprofessionalism in line with progress in sewerage field, and promote efficiency and

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cost effectiveness as well as transparency and accountability in sewerage systemdevelopment.

4.10.1 Objectives of CCTV Inspection

a) Enable detection of sewer defects such as cracks, deforms, collapse,dislocate and etc. which are not detected by normal means;

b) As a quality assurance measure to ensure sewers and sewer appurtenancesare constructed in conformability with approved design, specifications,workmanship as well as materials and fixtures used;

c) As a means to establish record to enhance accountability andprofessionalism on quality assurance for sewer construction.

4.10.2 Technical Requirements and References

a) Analysis of defects shall be based on WRc Manual for Sewer ConditionClassification Latest Edition;

b) Equipment and test devices to be used are as listed in Section 4.10.3.

c) For sewer with diameter larger than 1050 mm, Man-entry CCTV surveymode may be adopted unless it can be demonstrated that the CCTV can bemaintained in a stable position on or near the central axis of the sewer andimages captured are satisfactory and not distorted.

4.10.3 Equipment Specifications and Test Devices

4.10.3.1 Specifications for CCTV unit’s equipment

a. Solid state colours CCTV camera with pan & rotate features, together witha lighting unit, automatic date/ metre age.

b. A self powered tractor or crawler on which the camera is conveyed along apipeline under inspection in a stable manner.

c. Calibration chart for various sizes of sewer for the camera used.

d. Test device for the CCTV camera using 'Marconi Resolution Chart No.1' orits derivative to demonstrate satisfactory performance of the camera.

e. Test device for the monitor and video recorder to establish the effectivenessand accuracy of the 'on-site' monitor and video recorder.

f. The control unit comprises the camera unit, crawler control andscreenwriter. This console can be mounted permanently in a vehicle or useas portable system.

g. A video recorder for recording high quality video images.

h. A means of producing still images from the monitor screen.

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i. A PC-based site reporting system capable of producing reports customizedto the Contractor's needs and to include photographs captured directly fromvideo.

4.10.3.2 Software Requirements

Software standardisation using databank software that can produce report, based onWRc format.

4.10.3.3 Report Format

Report in VCD or other digital form to be submitted in MPEG format withminimum 352x240 pixels. Two copies of digital records and one copy of hardcopyreport shall be forwarded to JPP office.

a) For the diameter pipe greater than 600mm, it shall have zoomingcapabilities.

4.10.4. CCTV Inspection Requirements

The following areas area identified as the minimum coverage for CCTV inspection.

4.10.4.1 High Risk Areas

A 100% CCTV inspection shall be conducted for sewers laid in the ground withhigh risk of failure and having the following characteristics:

a) Deeper than average 6m or more

b) Pipe diameter above 600mm.

c) Areas that have restricted vehicular access for repair (e.g. central businessdistrict).

d) Crossings under buildings, lakes, rivers, roads and railway including theirreserve.

e) Ground slopes greater than 30o inclination.

f) All sewers installed using pipe jacking method.

g) All diversion or re-alignment of existing sewer networks.

h) All single private developments (with PE > 30), connecting to existingmain sewer.

4.10.4.2 General Inspection Coverage (for Sewer, Manholes and LateralConnections)

a) Initial CCTV testing & inspection shall be conducted for a minimum 10%random selection of sewers including all manholes and lateral propertyconnections in accordance with standard procedure.

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b) If the mandatory requirement of Clause 4.10.4.1 is less than 5% of theentire development area, the minimum CCTV testing & inspection is 10%as in Clause 4.10.4.2a. If the mandatory requirements of Clause 4.10.4.1 ismore than 5%, the minimum CCTV testing & inspection shall have anadditional of 10%.

c) Prior to taking over existing network that has been approved from anyowner or after rehabilitation works have been completed.

d) All new network undergoing intermediate inspection except:

i. Single Phase development with total sewer length less than 500mlong with no interval.

ii. Vacuum sewer.

4.10.4.3 Stage of Inspection

a) Stage 1- All projects are to start with stage 1 inspection where 10 % (bylength) of sewer network and property connections involved, shall berandomly selected and CCTV inspected.

b) Stage 2 - Should any Grade 3,4 or 5 conditions as defined in the Manual forSewer Condition Classification approve by the Commission, found in Stage1 inspection, the CCTV inspection shall proceed to Stage 2 inspection.Stage 2 inspections shall include another 40% of the sewer network to berandomly selected for CCTV inspection.

c) Stage 3- Should any Grade 3,4 or 5 conditions as defined in the Manual forSewer condition classification approve by the Commission, found in Stage2 inspection, the CCTV inspection shall proceed to Stage 3 where all theremaining network shall be CCTV inspected.

4.10.5 CCTV Inspection Implementation Procedure for New SewerNetwork

4.10.5.1. Activities to be completed before submitting for finalIntermediate Inspection.

a) All construction works have been completed and tested by the supervisingqualified person.

b) Sewer networks have been cleared of debris and are ready for inspection.

c) A CCTV Inspection Contractor licensed with the Commission has beenappointed to carry out the inspection.

4.10.5.2. Random selection of sewer to be inspected.

a) The list of sewer segments and house connections selected for CCTVinspection shall be recorded and the parties witnessing the selection processshall duly sign the record.

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b) Names and designations of all persons involved in the random selectionprocess as well as the time, date and place where the selection were carriedout shall be recorded in the report on the random selection process. Recordof the sewer segments randomly selected for CCTV inspection shall beincluded as appendix to the report.

c) The random selection process shall be completed in a single session.

4.10.5.3. CCTV inspection on site.

a) The CCTV inspection shall be carried out 7 days after notice issued by theCommission.

b) Inspection shall be carried out in within 24 hours after random selection hasbeen completed.

c) Once started, CCTV inspection for a project shall be carried out withoutany break. Should for any reason a break/delay of more than 24 hoursbecome necessary, the random selection process shall be repeated to selectthe remaining sewer segments for the inspection. Reasons for thebreak/delay shall be recorded.

d) Representative from the Commission or authorized person, consultantrepresentative and contractor responsible for the construction of the sewershall be present at the onset of CCTV inspection at each project site.

4.10.5.4. Documentation on CCTV recording

a) At the start of the CCTV recording, the following details must be recorded:

i. Date and starting time of inspection.

ii. Project name and location

iii. Names and designation of persons involved (i.e representative of theCommission or authorized person, consultant & contractor andCCTV contractor).

b) At the beginning of each CCTV recording for every segment of sewer shallbe marked with their respective code number with chainage together withthe date, start and end times of the recording.

c) After the CCTV inspection and recording have been completed for aproject, a copy of recorded CCTV shall be handover to the Commission orauthorized person immediately. Report on the CCTV inspection togetherwith the recording and recommendations shall be prepared by the CCTVcontractor and submitted to the relevant the Commission branch office orthe appointed agency not more than 7 days after the date of inspection. Theformat of reporting shall follow the standard that had been given (AppendixC). The copy of the tape (or other recording media used to store the record)containing the CCTV inspection records shall be submitted to theCommission Branch office or the appointed agency together with acertificate duly signed by the qualified person responsible for the CCTVinspection declaring the authenticity of the recording submitted and that the

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CCTV inspection has been done in accordance with the procedure stated inthis guideline.

4.10.6 Interpretation of Results from CCTV Inspection

a) Classification : Grade 1 to Grade 5 as per the Commission approve SewerAssessment Classification. Colour to show the defect grade descriptionshall be follow as:

i. Grade 1: Green

ii. Grade 2 : Blue

iii. Grade 3 : Orange

iv. Grade 4 : Brown

v. Grade 5 : Red

b) Grade 1 and 2 is acceptable constructional defects but may have otherminor defects. It can be accepted provided a performance bond has beensubmitted and the contractor undertake to rectify the defect within 30 days.

c) Sewer with Grade 3, 4 or 5 conditions has major structural defects and shallbe accepted. Relaid of the affected sewer segments is necessary.

4.10.7 Follow -Up Action to Be Taken

a) For Grade 1 and Grade 2, the developer shall rectify and make good to allthe defects in 30 days. These rectification works shall be witnessed by theparties concerned and agreed together that the works had been completed.The Commission or the authorised person may instruct CCTV inspection tobe carried out again. Under these grade classifications, the letter ofrecommendation for CFO will be released by the Commission or theauthorised agency.

b) For Grade 3, 4 or 5 classifications, the developer shall change, replace,relay or reconstruct the rejected works. Further CCTV inspection shall becarried out before acceptance. The letter of support for CFO will bereleased upon acceptance.

c) In the events of any blockages, damages, seepages and etc to the sewernetworks during the defects liability period, JPP may require the developerto carry out further CCTV inspection to determine the cause and extent ofthe problems that arises. CCTV inspection shall be carried out immediatelywithin 24 hours.

Table 4.1 provides the description of various defect grades

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Table 4.2 Defect Grades Descriptions

Grade 1

Occurances without damage and no cracks of pipe but only acceptable displacement onjoint where no visual infiltration can be observe: e.g.

Grade 2

Constructional and sewer product deficiencies or occurances with insignificant influenceto tightness, hydraulic or static pressure of pipe, etc.

Examples: Joint displaced large; badly torched intakes; minor deformation of plasticpipes (<5%); minor erosions; infiltration seeping; Cracks – joint, circumference,longitudinal; Debis, silt – 15%; Encrustation light.

Grade 3

Constructional, operational and maintenance deficiencies diminishing static, hydraulic,safety and tightness.

Examples: Infiltration dripping. (OMD); Open joint; untorched intakes; cracks; minordrainage obstructions such as calcide build ups; protruding laterals; minor damages topipe wall; individual root penetrations; corroded pipe wall; flexible pipe deformation(>5%); Lining defect.

Grade 4

Constructional and structural damages with no sufficient static safety, hydraulic ortightness.

Examples: axial/radial pipebursts; visually noticeable infiltration/exfiltration; cavities inpipe-wall; severe protruding; laterals severe root penetrations; severe corrosion of pipewall; Infiltration running; encrustation medium; minor deformation; flexible pipedeformation >15%

Grade 5

Major structural damaged where pipe is already or will shortly be impermeable.

Examples: collapsed or collapsed eminent; major deformation; deeply rooted pipe; anydrainage obstructions; pipe loses water or danger of backwater in basements etc

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4.11 Infiltration Test

4.11.1 General

Infiltration is an extraneous flow not contributed from households. Althoughdesign has allowed for certain amount of infiltration, a significant amount ofunexpected infiltration will overload both the collection sewers and the treatmentplant. To avoid any extra infiltration, a test maybe conducted on the gravity sewerlaid. If the force main is significantly below the groundwater table, an infiltrationtest is also highly recommended. When severe infiltration is found during sewerlaying, the source shall be investigated immediately. Infiltration test is normally conducted after backfill and after the groundwater levelhas stabilised. The procedures are as follows:

4.11.2 Procedure

a) Plug the inlets at all upstream open ends, after the groundwater level hasstabilised following backfilling.

b) Measure any infiltration from the sewer to the manhole or within manholeitself.

c) Conduct the measurement of infiltration for at least 24 hours.

d) Pass the infiltration test if the infiltration does not exceed 1 litre per hourper metre diameter per meter of pipe run.

4.11.3 Handling Test Failures

a) Conduct a light and mirror test to identify the location of the infiltration ifthe pipe is small and short.

b) Move an inflated rubber plug toward downstream end to isolate lengths ofleakage. Repeat the test procedure after each plug relocation

c) Conduct a CCTV inspection if the location of the infiltration can not beidentified by the light and mirror test or moving the inflated rubber plug.

d) Exhume and repair the fail section of the pipe.

4.12 Water-tightness Test

4.12.1 General

Visual inspection is usually sufficient to ensure the water-tightness of manhole andother ancillary structures. However, water-tightness test may be required if: a) Instruction from the authorised inspection person

b) Unsatisfactory features identified from the visual inspection

c) Suspicion of poor workmanship or poor materials

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d) Leakages revealed from other tests

e) Frequent surcharging of the structure is possible

The test should be carried out only after the structures have achieved sufficientstrength to withstand the test pressure. Where possible, the test shall be carried outbefore backfilled or concrete surrounded.

For manhole less than 1.5 m in depth, the manhole shall be filled with clean waterto the bottom of cover. For manhole more than 1.5 m in depth, the water head forthe test shall not be less than 1.5 m or the mean groundwater level, whichever islarger. For any other ancillary structure, the water shall be filled to the top of thestructure unless otherwise specified by the authorised inspection person.

The procedures for testing the manhole are listed below. For other ancillarystructures, the procedures can still be adopted. However, the height which thewater level should be tested shall follow the instruction from the authorisedinspection person.

4.12.2 Procedures

a) Fit a plug or stopper in all the openings.

b) Secure the plug/stopper to resist the full test pressure.

c) Provide a mean to remove the plug/stopper from the ground level safely iftest water is allowed to be discharged to the downstream.

(The plug/stopper may need to be remove while the structure is still full ofwater. Alternatively, a potable submersible pump might be sunk into thetest structure to remove the water.)

d) Fill the structure with clean water. Fill slowly to avoid any intense pressureimpact from the water.

e) Observe visually to identify any water leakage to the outside of thestructure. Drain the water to repair the leakage if necessary.

f) Otherwise, allow the water to stay in the test structure for 8 hours.Investigate any appreciable water loss.

g) Drain and dispose of the test water from the test structure in an appropriatemanner and to an suitable location.

APPENDIX A

Appendix A

Sewer Networks and Pump Stations Volume 3 Page 97

APPENDIX A

Figure A.3 : Standard Precast Concrete Manholes (Shallow, 2.5 to 5 metres, and > 5metres depth): Add standard drawing for large diameter manhole with RCchamber. Page 107.


Figure A.5 : Standard Deep Precast Concrete Manhole: Remove or reposition landingfor clear passage from manhole top, as landing may obstruct operationsactivity (eg. jetting hose).Page 109.


Figure A.6 : Standard External Drop Junction: Present susceptible to blockage.Improve construction details to minimise blockage Page 110.

a. Outlet for 90 deg bend pipe, to raise to min. 300 mm above crownof sewer pipe.

b. Size of drop pipe min. 300 mm dia.

Figure A.13 : Typical Induct Vent Detail: Delete this figure, as not applicable. Page 117.

Figure A.14 : Typical Details of a Wet Well Submersible Pump Station: Review, includealso typical details not using the circular wet well type (which is now notcommon). Page 118.

Figure A.18 : Buffer Zone for Pump Station with and without Super Structure: Bufferzone for fence to fence, add note “where located in high risk areas,brickwall fencing may be specified for safety”. Page 122.

Figure A.19 : Buffer Zone for Pump Station with and without Super Structure: Bufferzone for fence to fence, add note “where located in high risk areas,brickwall fencing may be specified for safety”. Page 123.

Note: Other figures added are distributed as hard copies for incorporation in the documents.

OTHER COMMENTS

a) Clause 2.5.2, 1 (Oil & Grease Trap) - Drawings submission by developersmust show O&G traps have been provided for these premises where grease and fatare likely to be discharged to sewers. Page 6.

b) To include a section on Inverted Siphons - Standard drawings for invertedsiphons to be included, but they must be designed for individually based on actuallocations.

c) Clause 2.2.4, (Structural Design Consideration for Manholes) - Iron steps inmanholes shall not be provided, for safety. Page 50.

Appendix A

Page 98 Volume 3 Malaysian SewerageIndustry Guidelines

Figure A1 : Standard Manhole Cover

5555

290

350

250

20 20 20

14

22

6

HINGE DEVICE BOLT HOLES

1. MANHOLE COVER AND FRAME MUST COMPLY WITH THE SPECIFICATION AND BE MANUFACTURED BY A MANUFACTURERAPPROVED BY SPAN

120

20

100

20

120

20

120

120

20

SECTION Y - YCOVER HINGE OPEN AT 90°

SECTION Y - YCOVER HINGE OPEN AT MINIMUM 100°

SECTION X - XTYPICAL LOCKING DEVICE

SECTION Y - YTYPICAL HINGE

DANGERCONFINED SPACE

DO NOT ENTER

DILARANG MASUKRUANG TERKURUNG

SEE DETAIL `3'

SEE DETAIL `2'

652

520

915

20

1025

520

5 25

NOTES:

226

3

SECTION Z-Z

55 55 65 55

140

( TYPICAL SURFACE DETAIL )

SECTION Z - Z

TYPICAL SECTION OF HEAVY DUTY D.I. MANHOLECOVER AND FRAME

(SECTION Y-Y)

TYPICAL DETAILS OF HEAVY DUTY D.I. MANHOLE

CLASS D400 "

MODEL NO. AND THEMARKING "BSEN 124

SEE DETAIL `1'

EMBOSSED LOGO(SEE DETAIL `X')

COVER AND FRAME

LOCKING AND

PLAN

DETAIL `1'

Z Z

PLACE OF MANUFACTUREMANUFACTURER'S NAME AND

DETAIL `X' : EMBOSSED LOGO

ALL CORNERS TO BE ROUNDED OFF

652

600

20

100

9

840

840

SERIAL NO.

20

50.5

50.5

60°

DETAIL `2' & '3' : EMBOSSED DESIGN

60

840

655

665

LIFTING DEVICE

Appendix A


Figure A2 : Plan View of Typical Manhole

INLE

TIN

LET

INLE

T

SEC

TIO

NAL

PLA

N V

IEW

FALL

CO

NC

RET

E R

ING

WIT

HPR

EC

AS

T R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK

. MIN

.

1:12

FALL

1:1

2

(DIA

. VAR

IES)

SEW

ER

PIP

E

OF

MA

NH

OLE

TY

PE

G

MIN

120

0

V.C

. CH

ANN

ELH

ALF

RO

UN

D

FALL

1:1

2

(DIA

. VAR

IES)

SEW

ER

PIP

E

FALL

1:1

2

SEC

TIO

NAL

PLA

N V

IEW

OF

MA

NH

OLE

TY

PE

C

MIN

120

0

INLE

T

SE

CTI

ON

AL P

LAN

VIE

W

FALL

CO

NC

RET

E R

ING

WIT

HP

REC

AST

REI

NFO

RC

ED

CO

NC

RET

E S

UR

RO

UN

D15

0 TH

K. M

IN.

1:12

FALL

1:1

2

(DIA

. VAR

IES)

SE

WE

R P

IPE

OF

MA

NH

OLE

TY

PE

E

MIN

120

0

CO

NC

RET

E R

ING

WIT

HPR

EC

AS

T R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK

. MIN

.

V.C

. CH

AN

NEL

HAL

F R

OU

ND

FALL

1:12

SEC

TIO

NA

L PL

AN

VIE

W

CO

NC

RET

E R

ING

WIT

HPR

EC

AS

T R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK.

MIN

.

OF

MA

NH

OLE

TY

PE B

MIN

120

0

FALL

1:12

(DIA

. VAR

IES)

SE

WER

PIP

E

FALL

1:12

SE

CTI

ON

AL P

LAN

VIE

W

(DIA

. VAR

IES)

SE

WE

R P

IPE

OF

MA

NH

OLE

TY

PE

A

MIN

120

0

FALL

1:12

FALL

1:12

V.C

. CH

ANN

ELH

ALF

RO

UN

D

FALL

1:

12FA

LL

1:12

INLE

T

HAL

F R

OU

ND

VC

INLE

TIN

LET

OU

TLET

CO

NC

RET

E R

ING

WIT

HP

RE

CAS

T R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK

. MIN

.

V.C

. CH

AN

NEL

HAL

F R

OU

ND

FALL

1:1

2

(DIA

. VAR

IES)

SEW

ER

PIP

E

SEC

TIO

NA

L PL

AN

VIE

WO

F M

AN

HO

LE T

YPE

F

MIN

120

0

CO

NC

RET

E R

ING

WIT

HPR

EC

AS

T R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK

. MIN

.

INLE

T

FALL

1:12

INLE

T

FALL

1:12

SEC

TIO

NA

L PL

AN

VIE

W

CO

NC

RET

E R

ING

WIT

HP

RE

CA

ST R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK.

MIN

.

(DIA

. VA

RIE

S)S

EWE

R P

IPE

OF

MA

NH

OLE

TY

PE D

MIN

120

0

OU

TLET

FALL

1:12

FALL

1:12

INLE

T

SEC

TIO

NA

L PL

AN

VIE

W

CO

NC

RET

E R

ING

WIT

HP

RE

CA

ST R

EIN

FOR

CED

CO

NC

RET

E SU

RR

OU

ND

150

THK.

MIN

.

OF

MA

NH

OLE

TY

PE H

MIN

120

0

FALL

1:12

FALL

1:12

INLE

T

V.C

. CH

ANN

ELH

ALF

RO

UN

DV.

C. C

HAN

NEL

HAL

F R

OU

ND

V.C

. CH

ANN

ELH

ALF

RO

UN

D

1. A

LL D

IME

NS

ION

S A

RE

IN M

ILLI

MET

RE

S U

NLE

SS

OTH

ERW

ISE

STA

TED

MAN

HO

LE O

PEN

ING

MAN

HO

LE O

PEN

ING

MAN

HO

LE O

PEN

ING

MAN

HO

LE O

PEN

ING

MAN

HO

LE O

PEN

ING

MA

NH

OLE

OPE

NIN

G

MAN

HO

LE O

PEN

ING

MAN

HO

LE O

PEN

ING

NO

TE :

2. D

IAM

ETE

R O

F PI

PE

INS

IDE

MA

NH

OLE

BA

SE T

O B

E O

F EQ

UA

L S

IZE

O

R L

AR

GE

R T

HA

N T

HE

INC

OM

ING

PIP

E D

IAM

ETE

R.

(STR

AIG

HT

THR

OU

GH

)

(CH

ANG

E O

F D

IRE

CTI

ON

- 90

° BE

ND

)

(DIA

MET

ER

CH

ANG

E)

(TH

RE

E IN

CO

MIN

G S

EWE

R)

(MU

LTIP

LE IN

CO

MIN

G)

(TW

O IN

CO

MIN

G S

EWER

)

(DIA

. VAR

IES

)S

EWE

R P

IPE

OU

TLET

OUTLET

(DIA

. VAR

IES

)S

EWE

R P

IPE

OU

TLET

OUTLET

OUTLET

(DIA

. VAR

IES)

SE

WE

R P

IPE

OU

TLET

(CH

ANG

E O

F D

IRE

CTI

ON

)(F

IRS

T M

AN

HO

LE)

Appendix A


Figure A3 : Typical Shallow Precast Concrete Manhole(Ground Level to Invert of Pipe 1.2m ≤ Depth < 2.5m

STA

ND

ARD

MA

NH

OLE

D.I

FRA

ME

AN

D C

OV

ER T

O D

ETA

ILS FI

LL W

ITH

1:3

CEM

EN

T M

OR

TAR

MIX

600

1:12

350 (MAX.)

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AM

EA

ND

CO

VE

R T

O D

ETAI

LS

600

FILL

WIT

H 1

:3 C

EM

ENT

MO

RTA

R M

IX

CA

ST

INS

ITU

CO

NC

RET

E S

UR

RO

UN

D

(150

TH

K. M

IN)

PR

EC

AST

RC

CO

VE

R S

LAB

WIT

H

UN

DE

RS

IDE

PA

INTE

D W

ITH

2 L

AY

ERS

OF

CO

AL

EP

OX

Y (1

00 T

HK.

MIN

.)

PR

EC

AS

T R

.C C

HA

MB

ER

RIN

G W

ITH

20

MIN

. IN

TER

NAL

LIN

ING

OF

HIG

H A

LUM

INA

CE

ME

NT

MO

RTA

R

PR

EC

AS

T R

.C M

AK

E U

P R

ING

S A

S R

EQ

UIR

ED

TO

MA

TCH

TO

P O

F M

AN

HO

LE C

OV

ER T

O

FIN

ISH

ED

SU

RFA

CE

LE

VE

L

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

CE

ME

NT

REN

DE

RIN

G)

PR

EC

AST

RC

CO

VER

SLA

B W

ITH

U

ND

ERS

IDE

PAI

NTE

D W

ITH

2 L

AY

ER

S O

F C

OA

L E

PO

XY

(100

TH

K. M

IN.)

PR

EC

AS

T R

.C C

HA

MB

ER R

ING

WIT

H 2

0 M

IN. I

NTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

CEM

EN

T M

OR

TAR

PR

ECA

ST

R.C

MA

KE

UP

RIN

GS

AS

RE

QU

IRED

TO

MA

TCH

TO

P O

F M

ANH

OLE

CO

VE

R T

O

FIN

ISH

ED

SU

RFA

CE

LE

VEL

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

CE

ME

NT

REN

DER

ING

)

FILL

WIT

H 1

:3 C

EME

NT

MO

RTA

R M

IX

CA

ST

INSI

TU C

ON

CR

ETE

SU

RR

OU

ND

(1

50 T

HK

. MIN

)

PR

EC

AS

T R

C C

OV

ER

SLA

B W

ITH

U

ND

ERS

IDE

PAI

NTE

D W

ITH

2 L

AY

ER

S O

F C

OA

L E

PO

XY

(100

TH

K. M

IN.)

PR

EC

AS

T R

.C C

HA

MB

ER R

ING

WIT

H 2

0 M

IN. I

NTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

C

EM

EN

T M

OR

TAR

PR

EC

AST

R.C

MAK

E U

P R

ING

S A

S R

EQ

UIR

ED

TO

MA

TCH

TO

P O

F M

AN

HO

LE C

OV

ER T

O

FIN

ISH

ED

SU

RFA

CE

LE

VEL

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BA

SE

T12-

150

B/W

AY

1:12

350 (MAX.)

STA

ND

ARD

MA

NH

OLE

D.I

FRA

ME

AN

D C

OV

ER T

O D

ETA

ILS

600

50 T

HK.

CE

ME

NTI

TIO

US

BLI

ND

ING

MIN

. 400

GR

AD

E 2

0/20

C

ON

C. B

ASE

T12-

150

B/W

AY

1:12

CAS

T IN

SITU

CO

NC

RE

TE S

UR

RO

UN

D

(150

TH

K. M

IN)

50 T

HK

. CE

MEN

TITI

OU

S B

LIN

DIN

GT1

2-15

0 B

/WA

Y

HA

LF R

OU

ND

PIP

E A

ND

BE

NC

HIN

G

SH

APE

D T

O D

IREC

T FL

OW

IN

DIR

EC

TIO

N O

F M

AIN

FLO

W

FOR

M C

HAN

NE

L U

SIN

G 4

0 TH

ICK

HIG

H

ALU

MIN

A C

EME

NT

MO

RTA

R W

HE

RE

CH

AN

GE

IN D

IREC

TIO

N O

R D

IAM

ETE

R

OC

CU

RS

THR

OU

GH

MA

NH

OLE

OR

TH

ERE

AR

E 2

OR

3 IN

CO

MIN

G S

EWER

S

CO

NC

RET

E B

EN

CH

ING

(2

0 H

IGH

ALU

MIN

A

CEM

EN

T R

EN

DE

RIN

G)

MIN

. 400

GR

AD

E 2

0/20

C

ON

C. B

ASE

50 T

HK

. CE

MEN

TITI

OU

SB

LIN

DIN

G

SEC

TIO

N A

-A(G

RO

UN

D L

EVEL

TO

INVE

RT

LEV

EL O

F PI

PE 1

.2 <

D <

2.5

MET

RES

)

SEC

TIO

N B

-B

FOR

M C

HAN

NE

L U

SIN

G 4

0 TH

ICK

HIG

H

ALU

MIN

A C

EME

NT

MO

RTA

R W

HE

RE

CH

AN

GE

IN D

IRE

CTI

ON

OR

DIA

ME

TER

OC

CU

RS

TH

RO

UG

H M

ANH

OLE

OR

TH

ERE

AR

E 2

OR

3

INC

OM

ING

SE

WER

S

(GR

OU

ND

LE

VEL

TO IN

VER

T LE

VEL

OF

PIPE

1.2

< D

< 2

.5 M

ETR

ES)

(GR

OU

ND

LEV

EL

TO IN

VER

T LE

VEL

OF

PIP

E 1

.2 <

D <

2.5

MET

RES

)S

ECTI

ON

A-A

(FR

EE D

RO

P <

600)

600 (MAX.)

NO

TES:

1. R

OC

KER

PIP

E S

HA

LL B

E 60

0 LO

NG

FO

R S

EWE

RS

UP

TO

300

DIA

MET

ER

AN

D 9

00 L

ON

G F

OR

LA

RG

ER

DIA

ME

TER

SEW

ER

S.

2. D

IME

NS

ION

S A

RE

IN M

ILIM

ETE

RS

UN

LES

S O

THE

RW

ISE

STA

TED

.

3. S

I IS

RE

QU

IRED

TO

DE

TER

MIN

E S

OIL

CO

ND

ITIO

N A

ND

RE

QU

IRE

ME

NT

FOR

PIL

ING

.

Ø600

B

A

B

PLA

N V

IEW

A

Appendix A


Figure A4 : Typical Shallow Precast Concrete Manhole with Backdro(Ground Level to Invert of Pipe 1.2m ≤ Depth < 2.5m)

350 (MAX.)

600

FILL

WIT

H 1

:3 C

EM

EN

T M

OR

TAR

MIX

125

375

375 125

3 no

s. Ø

12 G

ALV

AN

ISED

RA

G B

OLT

S W

ITH

GU

NM

ETA

L N

UTS

AN

D W

ASH

ER

S

12 T

HK

. M.S

PLA

TE

50 T

HK

. CE

MEN

TITI

OU

SB

LIN

DIN

G

DR

OP

MA

NH

OLE

90

DEG

. BE

ND

1:1 2

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AME

AN

D C

OV

ER T

O D

ETA

ILS

600

FILL

WIT

H 1

:3 C

EMEN

T M

OR

TAR

MIX

PR

EC

AS

T R

C C

OVE

R S

LAB

WIT

H

UN

DE

RSI

DE

PA

INTE

D W

ITH

2 L

AYE

RS

OF

CO

AL

EPO

XY

(100

µm T

HK

. MIN

.)

PR

EC

AS

T R

.C M

AK

E U

P R

ING

S A

S R

EQ

UIR

ED

TO M

ATC

H T

OP

OF

MA

NH

OLE

CO

VE

R T

O

FIN

ISH

ED

SU

RFA

CE

LEV

EL

1:12

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HE

RE

C

HA

NG

E IN

DIR

ECTI

ON

OR

DIA

MET

ER

O

CC

UR

S T

HR

OU

GH

MAN

HO

LE O

R

THE

RE

AR

E 2

OR

3 IN

CO

MIN

G S

EWE

RS

T12-

150

B/W

AY

50 T

HK

. CE

ME

NTI

TIO

US

BLI

ND

ING

MIN

. 400

GR

ADE

20/

20

CO

NC

. BAS

ECLE

AR

AN

D R

OU

GH

EN

SU

RFA

CE

OF

MA

NH

OLE

AN

D A

PP

LY N

EA

T C

ON

CR

ETE

P

AS

TE P

RIO

R T

O P

OU

RIN

G S

UP

PO

RT

FOR

D

RO

P SE

CTI

ON

12 D

IA. G

ALV

AN

ISE

D R

AG

BO

LTS

WIT

H

GU

NM

ETA

L N

UT

AN

D W

AS

HE

RS

1/2Ø+100

CO

VE

R P

LATE

DET

AILS

DE

TAIL

'A'

SE

E D

ETA

IL 'A

'

Ø600

A A

BB

PLA

N V

IEW

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

C

EM

EN

T R

EN

DE

RIN

G)

PR

EC

AST

R.C

CH

AM

BER

RIN

G W

ITH

20

MIN

. IN

TER

NAL

LIN

ING

OF

HIG

H A

LUM

INA

C

EM

EN

T M

OR

TAR

(GR

OU

ND

LE

VE

L TO

INV

ER

T LE

VE

L O

F P

IPE

1.2

< D

< 2

.5 M

ETR

ES)

SE

CTI

ON

B-B

(BA

CK

DR

OP

> 6

00)

SE

CTI

ON

A-A

(BA

CK

DR

OP

> 6

00)

(GR

OU

ND

LE

VE

L TO

INV

ER

T LE

VE

L O

F P

IPE

1.2

< D

< 2

.5 M

ETR

ES)

CA

ST

INS

ITU

CO

NC

RET

E S

UR

RO

UN

D (1

50 T

HK

. MIN

)

NO

TES:

1. R

OC

KE

R P

IPE

SH

ALL

BE

600

LO

NG

FO

R S

EW

ER

S U

P T

O

30

0 D

IAM

ETE

R A

ND

900

LO

NG

FO

R L

AR

GE

R D

IAM

ETE

R S

EW

ER

S.

2. D

IME

NS

ION

S A

RE

IN M

ILIM

ETE

RS

UN

LES

S O

THE

RW

ISE

STA

TED

.

3. S

I IS

RE

QU

IRE

D T

O D

ETE

RM

INE

SO

IL C

ON

DIT

ION

AN

D R

EQ

UIR

EM

ENT

FOR

PIL

ING

.

STA

ND

AR

D M

AN

HO

LE D

.I FR

AM

EA

ND

CO

VER

TO

DE

TAIL

S

CA

ST

INS

ITU

CO

NC

RE

TE S

UR

RO

UN

D

(150

TH

K. M

IN)

PR

EC

AS

T R

C C

OV

ER

SLA

B W

ITH

U

ND

ERS

IDE

PAI

NTE

D W

ITH

2 L

AY

ER

S O

F C

OA

L E

PO

XY

(100

TH

K. M

IN.)

PR

EC

AST

R.C

CH

AM

BER

RIN

G W

ITH

20

MIN

. IN

TER

NAL

LIN

ING

OF

HIG

H A

LUM

INA

C

EM

EN

T M

OR

TAR

PR

EC

AS

T R

.C M

AKE

UP

RIN

GS

AS

RE

QU

IRE

D

TO M

ATC

H T

OP

OF

MAN

HO

LE C

OV

ER

TO

FI

NIS

HE

D S

UR

FAC

E L

EVE

L

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

C

EM

EN

T R

EN

DER

ING

)

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HE

RE

CH

AN

GE

IN D

IRE

CTI

ON

OR

DIA

MET

ER O

CC

UR

S

THR

OU

GH

MA

NH

OLE

OR

TH

ERE

AR

E 2

OR

3

INC

OM

ING

SE

WE

RS

MIN

. 400

GR

AD

E 2

0/20

C

ON

C. B

ASE

T12-

150

B/W

AY

1:12

Appendix A


Figure A5 : Typical Medium Precast Concrete Manhole(Ground Level to Invert of Pipe 2.5m ≤ Depth < 5m)

SEC

TIO

N A

-A

(GR

OU

ND

LE

VEL

TO

INV

ER

T LE

VE

L O

F PI

PE 2

.5 <

D <

5 M

ETR

ES)

SEC

TIO

N B

-B

(GR

OU

ND

LEV

EL

TO IN

VER

T LE

VE

L O

F PI

PE 2

.5 <

D <

5 M

ETR

ES)

SE

CTI

ON

A-A

(FR

EE D

RO

P <

600

)

(GR

OU

ND

LEV

EL

TO IN

VER

T LE

VE

L O

F PI

PE 2

.5 <

D <

5 M

ETR

ES)

NO

TES:

1. R

OC

KER

PIP

E S

HAL

L BE

600

LO

NG

FO

R S

EWER

S U

P TO

300

DIA

ME

TER

AN

D 9

00 L

ON

G F

OR

LA

RG

ER D

IAM

ETE

R S

EWE

RS.

2. D

IME

NSI

ON

S A

RE

IN M

ILIM

ETE

RS

UN

LESS

OTH

ERW

ISE

STAT

ED.

3. S

I IS

REQ

UIR

ED T

O D

ETE

RM

INE

SO

IL C

ON

DIT

ION

AN

D R

EQU

IREM

ENT

FOR

PIL

ING

.

PLA

N V

IEW

A

BB

A

STA

ND

AR

D M

ANH

OLE

D.I

FRAM

EA

ND

CO

VER

TO

DET

AILS

FILL

WIT

H 1

:3 C

EMEN

T M

OR

TAR

MIX

350(MAX.)

(150

TH

K. M

IN)

CAS

T IN

SITU

CO

NC

RET

E SU

RR

OU

ND

PR

ECAS

T R

.C M

AKE

UP

RIN

GS

AS R

EQU

IRED

TO

M

ATC

H T

OP

OF

MAN

HO

LE C

OVE

R T

O F

INIS

HED

SU

RFA

CE

LEVE

L

FOR

M C

HAN

NE

L U

SIN

G 4

0 TH

ICK

HIG

H

ALU

MIN

A C

EM

EN

T M

OR

TAR

WH

ERE

CH

ANG

E IN

DIR

ECTI

ON

OR

DIA

MET

ER O

CC

UR

S TH

RO

UG

H M

AN

HO

LE O

R T

HER

E AR

E 2

OR

3

INC

OM

ING

SEW

ERS

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BAS

E

T12-

150

B/W

AY

1:12

50 T

HK

. CEM

ENTI

TIO

US

BLI

ND

ING

PREC

AST

R.C

. CH

AM

BER

RIN

G W

ITH

20

MIN

. IN

TER

NA

L LI

NIN

G O

F H

IGH

ALU

MIN

A C

EMEN

T M

OR

TAR

PR

ECA

ST R

.C. T

APER

TO

P PA

INTE

D IN

TER

NAL

LY

WIT

H 2

LA

YER

S O

F C

OAL

TAR

EPO

XY

CO

NC

RET

E B

ENC

HIN

G (2

0 H

IGH

A

LUM

INA

CE

ME

NT

REN

DER

ING

)

600

HAL

F R

OU

ND

PIP

E A

ND

BEN

CH

ING

IN

GR

ADE

2O

HIG

H A

LUM

INA

CEM

ENT

SH

APED

TO

DIR

ECT

FLO

W IN

D

IREC

TIO

N O

F M

AIN

FLO

W

600 (MAX.)

350(MAX.)

(150

TH

K. M

IN)

CA

ST IN

SIT

U C

ON

CR

ETE

SUR

RO

UN

D

PRE

CAS

T R

.C M

AKE

UP

RIN

GS

AS R

EQU

IRED

TO

M

ATC

H T

OP

OF

MA

NH

OLE

CO

VER

TO

FIN

ISH

ED

SU

RFA

CE

LEV

EL

STAN

DAR

D M

AN

HO

LE D

.I FR

AME

AND

CO

VER

TO

DET

AILS

FILL

WIT

H 1

:3 C

EM

EN

T M

OR

TAR

MIX

600

1 :12

1 :12

600

350 (MAX.)

STA

ND

ARD

MA

NH

OLE

D.I

FRAM

EA

ND

CO

VER

TO

DET

AILS

FILL

WIT

H 1

:3 C

EMEN

T M

OR

TAR

MIX

PR

ECAS

T R

.C M

AKE

UP

RIN

GS

AS R

EQU

IRED

TO

MA

TCH

TO

P O

F M

ANH

OLE

CO

VER

TO

FI

NIS

HED

SU

RFA

CE

LEVE

L

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BAS

E

T12-

150

B/W

AY50

TH

K. C

EMEN

TITI

OU

SBL

IND

ING

Ø600

FOR

M C

HAN

NEL

USI

NG

40

THIC

K H

IGH

AL

UM

INA

CEM

ENT

MO

RTA

R W

HER

E C

HAN

GE

IN D

IREC

TIO

N O

R D

IAM

ETER

OC

CU

RS

THR

OU

GH

MAN

HO

LE O

R T

HER

E AR

E 2

OR

3

INC

OM

ING

SEW

ERS

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BAS

E

T12-

150

B/W

AY

1:12

50 T

HK.

CE

ME

NTI

TIO

US

BLIN

DIN

G

PR

EC

AST

R.C

. CH

AMBE

R R

ING

WIT

H 2

0 M

IN.

INTE

RN

AL L

ININ

G O

F H

IGH

ALU

MIN

A C

EMEN

T M

OR

TAR

PRE

CAS

T R

.C. T

APE

R T

OP

PA

INTE

D IN

TER

NAL

LY

WIT

H 2

LA

YER

S O

F C

OAL

TAR

EPO

XY

CO

NC

RE

TE B

ENC

HIN

G (2

0 H

IGH

AL

UM

INA

CEM

ENT

REN

DER

ING

)

(150

TH

K. M

IN)

CAS

T IN

SIT

U C

ON

CR

ETE

SUR

RO

UN

D

INTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

PRE

CA

ST R

.C C

HAM

BER

RIN

G W

ITH

20

MIN

.

CEM

EN

T M

OR

TAR

WIT

H 2

LAY

ERS

OF

CO

AL T

AR E

POXY

PR

ECAS

T R

.C T

APER

TO

P P

AIN

TED

INTE

RN

ALLY

FOR

M C

HAN

NEL

USI

NG

40

THIC

K H

IGH

AL

UM

INA

CEM

ENT

MO

RTA

R W

HER

E C

HAN

GE

IN D

IRE

CTI

ON

OR

DIA

MAT

ER O

CC

UR

S TH

RO

UG

H M

AN

HO

LE O

R T

HER

E AR

E 2

OR

3

INC

OM

ING

SEW

ERS

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

CEM

ENT

REN

DER

ING

)

Appendix A


Figure A6 : Typical Medium Precast Concrete Manhole with backdrop(Ground Level to Invert of Pipe 2.5m ≤ Depth < 5m)

600

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AM

EA

ND

CO

VE

R T

O D

ETA

ILS

FILL

WIT

H 1

:3 C

EM

ENT

MO

RTA

R M

IX

PR

EC

AS

T R

.C M

AKE

UP

RIN

GS

AS

RE

QU

IRED

TO

MA

TCH

TO

P O

F M

AN

HO

LE C

OV

ER

TO

FI

NIS

HE

D S

UR

FAC

E L

EVE

L

I : 1

2

I : 1

2

CO

NC

RE

TE B

EN

CH

ING

(2

0 H

IGH

ALU

MIN

A

CE

ME

NT

RE

ND

ER

ING

)

SE

CTI

ON

B-B

(BA

CK

DR

OP

> 6

00)

(GR

OU

ND

LEV

EL

TO IN

VE

RT

LEV

EL

OF

PIP

E 2

.5 <

D <

5 M

ETR

ES

)

SE

CTI

ON

A-A

(BA

CK

DR

OP

> 6

00)

(GR

OU

ND

LE

VE

L TO

INV

ER

T LE

VE

L O

F P

IPE

2.5

< D

< 5

MET

RE

S)

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RE

TE S

UR

RO

UN

D

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

CE

ME

NT

RE

ND

ERIN

G)

NO

TES:

1. R

OC

KER

PIP

E S

HA

LL B

E 6

00 L

ON

G F

OR

SE

WE

RS

UP

TO

30

0 D

IAM

ETE

R A

ND

900

LO

NG

FO

R L

AR

GE

R D

IAM

ETE

R S

EWE

RS

.

2. D

IME

NS

ION

S A

RE

IN M

ILIM

ETE

RS

UN

LES

S O

THE

RW

ISE

STA

TED

.

3. S

I IS

RE

QU

IRED

TO

DE

TER

MIN

E S

OIL

CO

ND

ITIO

N A

ND

RE

QU

IRE

ME

NT

FOR

PIL

ING

.

DET

AIL

'A'

CO

VE

R P

LATE

DET

AIL

S

PLA

N V

IEW

SEE

DE

TAIL

'A'

A

BB

A

CLE

AR

AN

D R

OU

GH

EN

SU

RFA

CE

OF

MAN

HO

LE A

ND

APP

LY N

EA

T C

ON

CP

ASTE

PR

IOR

TO

PO

UR

ING

SU

PP

OR

TFO

R D

RO

P S

EC

TIO

N

DR

OP

MA

NH

OLE

90

DE

G. B

EN

DI :

12

Ø600

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RE

TE S

UR

RO

UN

D

INTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

P

RE

CA

ST R

.C C

HA

MB

ER R

ING

WIT

H 2

0 M

IN.

CE

ME

NT

MO

RTA

R

WIT

H 2

LA

YE

RS

OF

CO

AL

TAR

EPO

XYP

RE

CA

ST

R.C

TA

PE

R T

OP

PA

INTE

D IN

TER

NA

LLY

FOR

M C

HAN

NE

L U

SIN

G 4

0 TH

ICK

HIG

H

ALU

MIN

A C

EM

EN

T M

OR

TAR

WH

ERE

CH

AN

GE

IN D

IRE

CTI

ON

OR

DIA

MA

TER

OC

CU

RS

TH

RO

UG

H M

ANH

OLE

OR

TH

ER

E A

RE

2 O

R 3

IN

CO

MIN

G S

EW

ER

S

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BAS

E

T12-

150

B/W

AY

50 T

HK

. CE

ME

NTI

TIO

US

BLI

ND

ING

INTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

P

RE

CA

ST

R.C

CH

AM

BER

RIN

G W

ITH

20

MIN

.

CE

ME

NT

MO

RTA

R

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HE

RE

CH

ANG

E

IN D

IRE

CTI

ON

OR

DIA

MET

ER O

CC

UR

S TH

RO

UG

H M

ANH

OLE

OR

TH

ER

E AR

E 2

OR

3

INC

OM

ING

SE

WE

RS

T12-

150

B/W

AY

50 T

HK

. CE

MEN

TITI

OU

S B

LIN

DIN

G

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BA

SE

600

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AM

EA

ND

CO

VE

R T

O D

ETA

ILS

FILL

WIT

H 1

:3 C

EM

EN

T M

OR

TAR

MIX

WIT

H 2

LA

YE

RS

OF

CO

AL T

AR

EPO

XY

PR

EC

AS

T R

.C T

AP

ER

TO

P PA

INTE

D IN

TER

NAL

LY

PR

EC

AS

T R

.C M

AKE

UP

RIN

GS

AS

RE

QU

IRED

TO

MA

TCH

TO

P O

F M

AN

HO

LE C

OV

ER

TO

FI

NIS

HE

D S

UR

FAC

E L

EV

EL

125

375

375 125

3 no

s. Ø

12 G

ALV

AN

ISE

D R

AG

BO

LTS

WIT

H G

UN

ME

TAL

NU

TS

AN

D W

AS

HE

RS

12 T

HK.

M.S

PLA

TE

12 D

IA. G

ALV

AN

ISE

D R

AG

BOLT

S W

ITH

G

UN

ME

TAL

NU

T AN

D W

ASH

ER

S

1/2Ø+100

Appendix A


Figure A7 : Typical Deep Precast Concrete Manhole(Ground Level to Invert of Pipe 5m ≤ Depth ≤ 9m)

1 :1 2

1 :1 2

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RE

TE S

UR

RO

UN

D

INTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

PR

ECA

ST

R.C

CH

AM

BE

R R

ING

WIT

H 2

0 M

IN.

CE

ME

NT

MO

RTA

R

WIT

H 2

LA

YE

RS

OF

CO

AL T

AR E

PO

XY

PR

EC

AS

T R

.C T

AP

ER

TO

P P

AIN

TED

INTE

RN

ALLY

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HER

E C

HA

NG

E

IN D

IRE

CTI

ON

OR

DIA

MAT

ER

OC

CU

RS

THR

OU

GH

MA

NH

OLE

OR

TH

ERE

AR

E 2

OR

3

INC

OM

ING

SEW

ERS

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

C

EM

EN

T R

EN

DER

ING

)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AME

AND

CO

VE

R T

O D

ETAI

LS

FILL

WIT

H 1

:3 C

EM

ENT

MO

RTA

R M

IX

350(MAX.)

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RET

E S

UR

RO

UN

D

PR

EC

AS

T R

.C M

AK

E U

P R

ING

S A

S R

EQU

IRED

TO

M

ATC

H T

OP

OF

MA

NH

OLE

CO

VER

TO

FIN

ISH

ED

S

UR

FAC

E L

EVE

L

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HER

E C

HAN

GE

IN D

IRE

CTI

ON

OR

DIA

MET

ER O

CC

UR

S TH

RO

UG

H M

AN

HO

LE O

R T

HER

E AR

E 2

OR

3

INC

OM

ING

SEW

ERS

MIN

. 400

GR

AD

E 2

0/20

C

ON

C. B

ASE

T12-

150

B/W

AY

1:12

50 T

HK

. CE

ME

NTI

TIO

US

BLI

ND

ING

PRE

CA

ST

R.C

. CH

AM

BE

R R

ING

WIT

H 2

0 M

IN.

INTE

RN

AL L

ININ

G O

F H

IGH

ALU

MIN

A C

EME

NT

MO

RTA

R

PR

EC

AS

T R

.C. T

AP

ER

TO

P P

AIN

TED

INTE

RN

ALLY

W

ITH

2 L

AY

ER

S O

F C

OAL

TAR

EPO

XY

CO

NC

RE

TE B

EN

CH

ING

(20

HIG

H

ALU

MIN

A C

EM

EN

T R

END

ERIN

G)

600

HA

LF R

OU

ND

PIP

E A

ND

BEN

CH

ING

IN

GR

AD

E 2O

HIG

H A

LUM

INA

CEM

ENT

SH

AP

ED

TO

DIR

EC

T FL

OW

IN

DIR

EC

TIO

N O

F M

AIN

FLO

W

600 (MAX.)

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BAS

E

T12-

150

B/W

AY50

TH

K. C

EM

EN

TITI

OU

SB

LIN

DIN

G

Ø600

A A

BB

PLAN

VIE

W

SEC

TIO

N A

-A (F

REE

DR

OP

< 60

0)(G

RO

UN

D L

EVE

L TO

INVE

RT

LEV

EL O

F PI

PE 5

< D

< 9

MET

RES

)SE

CTI

ON

B-B

(GR

OU

ND

LE

VEL

TO IN

VER

T LE

VEL

OF

PIPE

5 <

D <

9 M

ETR

ES)

SEC

TIO

N A

-A(G

RO

UN

D L

EVEL

TO

INV

ERT

LEVE

L O

F PI

PE 5

< D

< 9

MET

RES

)

600

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AME

AN

D C

OV

ER

TO

DET

AILS

FILL

WIT

H 1

:3 C

EME

NT

MO

RTA

R M

IX

PRE

CA

ST

R.C

MA

KE

UP

RIN

GS

AS R

EQ

UIR

ED

TO M

ATC

H T

OP

OF

MA

NH

OLE

CO

VER

TO

FI

NIS

HE

D S

UR

FAC

E LE

VEL

STA

ND

AR

D M

AN

HO

LE D

.I FR

AME

AN

D C

OV

ER

TO

DET

AIL

S

FILL

WIT

H 1

:3 C

EMEN

T M

OR

TAR

MIX

350(MAX.)

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RE

TE S

UR

RO

UN

D

PR

EC

AS

T R

.C M

AK

E U

P R

ING

S A

S R

EQU

IRED

TO

M

ATC

H T

OP

OF

MA

NH

OLE

CO

VER

TO

FIN

ISH

ED

S

UR

FAC

E L

EVE

L

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HER

E C

HAN

GE

IN D

IRE

CTI

ON

OR

DIA

MET

ER O

CC

UR

S

THR

OU

GH

MA

NH

OLE

OR

TH

ER

E AR

E 2

OR

3

INC

OM

ING

SE

WE

RS

MIN

. 400

GR

AD

E 20

/20

CO

NC

. BAS

E

T12-

150

B/W

AY

1:12

50 T

HK

. CE

ME

NTI

TIO

US

BLI

ND

ING

PRE

CA

ST

R.C

. CH

AM

BE

R R

ING

WIT

H 2

0 M

IN.

INTE

RN

AL L

ININ

G O

F H

IGH

ALU

MIN

A C

EME

NT

MO

RTA

R

PR

EC

AS

T R

.C. T

AP

ER

TO

P P

AIN

TED

INTE

RN

ALLY

W

ITH

2 L

AY

ER

S O

F C

OA

L TA

R E

PO

XY

CO

NC

RE

TE B

EN

CH

ING

(20

HIG

H

ALU

MIN

A C

EM

EN

T R

END

ERIN

G)

600

NO

TES:

1. R

OC

KE

R P

IPE

SH

ALL

BE

600

LO

NG

FO

R S

EWER

S U

P TO

300

DIA

ME

TER

AN

D 9

00 L

ON

G F

OR

LA

RG

ER D

IAM

ETE

R S

EWER

S.

2. D

IME

NS

ION

S A

RE

IN M

ILIM

ETE

RS

UN

LES

S O

THER

WIS

E S

TATE

D.

3. S

I IS

RE

QU

IRE

D T

O D

ETE

RM

INE

SO

IL C

ON

DIT

ION

AN

D R

EQU

IREM

ENT

FOR

PIL

ING

.

Appendix A


Figure A8 : Typical Deep Precast Concrete Manhole with Backdrop(Ground Level to Invert of Pipe 5m ≤ Depth ≤ 9m)

(GR

OU

ND

LE

VE

L TO

INV

ER

T LE

VE

L O

F P

IPE

5 <

D <

9 M

ETR

ES)C

LEA

R A

ND

RO

UG

HEN

SU

RFA

CE

OF

MAN

HO

LE A

ND

APP

LY N

EAT

CO

NC

PAS

TE P

RIO

R T

O P

OU

RIN

G S

UPP

OR

TFO

R D

RO

P S

EC

TIO

N

DR

OP

MA

NH

OLE

90

DEG

. BEN

DI :

12

125

375

375 125

3 no

s. Ø

12 G

ALV

AN

ISE

D R

AG

B

OLT

S W

ITH

GU

NM

ETA

L N

UTS

A

ND

WAS

HE

RS

12 T

HK.

M.S

PLA

TE

CO

VE

R P

LATE

DET

AIL

S

SEE

DET

AIL

'A'

12 D

IA. G

ALV

AN

ISE

D R

AGBO

LTS

WIT

H

GU

NM

ETA

L N

UT

AN

D W

ASH

ER

S

1/2Ø+100

Ø600A A

BB

PLA

N V

IEW

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RE

TE S

UR

RO

UN

D

INTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

P

RE

CA

ST R

.C C

HAM

BER

RIN

G W

ITH

20

MIN

.

CEM

EN

T M

OR

TAR

WIT

H 2

LA

YE

RS

OF

CO

AL T

AR

EP

OXY

PR

EC

AS

T R

.C T

AP

ER T

OP

PAIN

TED

INTE

RN

ALL

Y

FOR

M C

HAN

NE

L U

SIN

G 4

0 TH

ICK

HIG

H

ALU

MIN

A C

EM

EN

T M

OR

TAR

WH

ER

E C

HA

NG

E IN

DIR

EC

TIO

N O

R D

IAM

ATER

OC

CU

RS

THR

OU

GH

MA

NH

OLE

OR

TH

ERE

AR

E 2

OR

3

INC

OM

ING

SE

WE

RS

MIN

. 400

GR

ADE

20/2

0 C

ON

C. B

ASE

T12-

150

B/W

AY

50 T

HK

. CE

MEN

TITI

OU

SB

LIN

DIN

G

INTE

RN

AL

LIN

ING

OF

HIG

H A

LUM

INA

PR

EC

AST

R.C

CH

AM

BE

R R

ING

WIT

H 2

0 M

IN.

CE

ME

NT

MO

RTA

R

FOR

M C

HA

NN

EL

US

ING

40

THIC

K H

IGH

A

LUM

INA

CE

ME

NT

MO

RTA

R W

HER

E C

HAN

GE

IN

DIR

EC

TIO

N O

R D

IAM

ETE

R O

CC

UR

S TH

RO

UG

H M

ANH

OLE

OR

TH

ER

E AR

E 2

OR

3

INC

OM

ING

SE

WE

RS

T12-

150

B/W

AY

50 T

HK.

CEM

ENTI

TIO

US

BLI

ND

ING

MIN

. 400

GR

ADE

20/2

0 C

ON

C. B

ASE

CO

NC

RE

TE B

EN

CH

ING

(2

0 H

IGH

ALU

MIN

A C

EM

EN

T R

EN

DER

ING

)

(150

TH

K. M

IN)

CA

ST

INS

ITU

CO

NC

RET

E SU

RR

OU

ND

CO

NC

RE

TE B

ENC

HIN

G

(20

HIG

H A

LUM

INA

C

EM

EN

T R

EN

DER

ING

)

NO

TES:

1. R

OC

KER

PIP

E S

HAL

L BE

600

LO

NG

FO

R S

EW

ER

S U

P T

O

30

0 D

IAM

ETE

R A

ND

900

LO

NG

FO

R L

AR

GE

R D

IAM

ETE

R S

EWE

RS.

2. D

IME

NS

ION

S A

RE

IN M

ILIM

ETE

RS

UN

LES

S O

THE

RW

ISE

STA

TED

.

3. S

I IS

RE

QU

IRED

TO

DE

TER

MIN

E S

OIL

CO

ND

ITIO

N A

ND

RE

QU

IRE

MEN

T FO

R P

ILIN

G.

DET

AIL

'A'

600

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AM

EA

ND

CO

VER

TO

DE

TAIL

S

FILL

WIT

H 1

:3 C

EME

NT

MO

RTA

R M

IX

WIT

H 2

LA

YER

S O

F C

OA

L TA

R E

POXY

PR

EC

AS

T R

.C T

AP

ER

TO

P P

AIN

TED

INTE

RN

ALLY

PR

EC

AST

R.C

MAK

E U

P R

ING

S A

S R

EQ

UIR

ED

TO M

ATC

H T

OP

OF

MAN

HO

LE C

OV

ER T

O

FIN

ISH

ED

SU

RFA

CE

LE

VEL

600

350 (MAX.)

STA

ND

AR

D M

AN

HO

LE D

.I FR

AME

AN

D C

OV

ER T

O D

ETA

ILS

FILL

WIT

H 1

:3 C

EMEN

T M

OR

TAR

MIX

PR

EC

AS

T R

.C M

AKE

UP

RIN

GS

AS

RE

QU

IRED

TO

MA

TCH

TO

P O

F M

AN

HO

LE C

OV

ER T

O

FIN

ISH

ED

SU

RFA

CE

LEV

EL

SEC

TIO

N A

-A (B

AC

KD

RO

P >

600

)(G

RO

UN

D L

EV

EL

TO IN

VE

RT

LEV

EL

OF

PIP

E 5

< D

< 9

ME

TRE

S)S

EC

TIO

N B

-B (B

AC

KD

RO

P >

600

)

Appendix A


Figure A9 : Typical Details of Large Diameter Manhole (LDM) Type

PLA

N

SE

CTI

ON

A-A

GR

D. L

EV.

150m

m C

ON

C.

SU

RR

OU

ND

1200

mm

DIA

. A

CC

ESS

C

HAM

BER

WIT

H

12m

m H

IGH

A

LUM

INA

LIN

ING

CO

VER

PLA

TE

SE

CTI

ON

B-B

LAR

GE

DIA

ME

TER

MA

NH

OLE

WIT

H IN

VER

T LE

VEL

OF

INC

OM

ING

BR

AN

CH

SE

WE

R A

BOVE

R.C

. CH

AM

BER

50m

m T

HK.

C

ON

C. S

CR

EED

CO

NC

. C

HAM

BER

GR

ADE

20/2

0 C

ON

C.

SUR

RO

ND

DIA. OF MAIN SEW

ER

(VAR

IES)

150

150

GR

D. L

EV.

150m

m C

ON

C.

SUR

RO

UN

D

1200

mm

DIA

. AC

CES

S C

HAM

BER

WIT

H

12m

m H

IGH

AL

UM

INA

LIN

ING

MAN

HO

LE T

O B

E ID

ENTI

CAL

TO

ST

AND

ARD

P

RE

CAS

T M

ANH

OLE

675

DIA

.O

PEN

ING

GR

ADE

30

CO

NC

RET

E W

ITH

12m

m

INTE

RN

AL H

A LI

NIN

G12

mm

HA

LIN

ING

TO

CH

ANN

EL

BEN

CH

ING

W

ALLS

AN

D T

OP

SLA

B

150m

m

CH

AMBE

R

6mm

DIA

. HEA

VY

GM

S (R

EFE

R T

O

DET

AIL

À')

BR

ANC

H

SEW

ER

STAN

DAR

D

LEN

GTH

OF

PIP

EWO

RK

TO

BE S

ET IN

M

ANH

OLE

D (VARIES)

3/4 D

1/4 D

50m

m T

HK.

C

ON

C. S

CR

EED

GR

AD

E 20

WIT

H

12m

m IN

TER

NAL

H

A LI

NIN

G

INS

TALL

2 N

OS.

A

PPR

OPV

ED S

TAIN

LESS

ST

EEL

CH

AIN

AT

D/S

SID

E O

F M

H. O

NLY

DEPTH VARIES

1800 MIN.

SE

CTI

ON

D-D

AA

CC

SE

CTI

ON

AL

PLA

N C

-C

SE

CTI

ON

E-E

INVE

RT

LEVE

L

12m

m H

A LI

NIN

G

BR

ANC

H

SEW

ER

MAI

N

SEW

ER

INV

ERT

LEVE

L

TO SUIT

500

500

300

30050

mm

TH

K.

CO

NC

. SC

REE

DC

ON

C. G

RAD

E 20

/20

D

EE

D

1:12 FALL

FOO

T H

OLE

S AT

300

mm

C

/C

PLA

STIC

S

AFE

TY

CH

AIN

PLA

STIC

S

AFE

TY

CH

AIN

INVE

RT

LEVE

L

MO

ULD

ED

CH

ANN

EL

BRAN

CH

SE

WER

MIN. 150

675m

m D

IA.

OPE

NIN

G

WIT

H

GR

ATIN

G

TW

AT

W

T W A TW

DE

TAIL

À'

EXP

AND

ITE

EXP

OC

RET

E U

A O

R S

IMIL

AR A

PPR

OVE

D

6mm

DIA

. HE

AVY

GM

S H

EXAG

ON

BO

LT

6mm

DIA

. HEA

VY

GM

S

APP

RO

VED

S

TAIN

LESS

S

TEEL

CH

AIN

6mm

DIA

. ST

AIN

LESS

ST

EEL

BOLT

A

ND

NU

T

MAS

S C

ON

C.

WAL

L

50

20

38

50

30

TYPE

INTE

RN

AL

WID

TH,

À' (

mm

)

MAI

N S

EW

ER

DIA

. (m

m)

INTE

RN

AL

CH

ANN

EL

STR

AIG

HT

THR

OU

GH

TO

BEN

DS

N.E

. 22.

5

INTE

RN

AL C

HAN

NEL

B

END

S N

.E. 2

2.5

N.E

. 90

D E F

1900

2200

2500

1050

, 120

0

1350

, 150

0

1650

, 180

0

900,

975

, 105

0

1200

, 135

0

1500

, 165

0

150m

m C

ON

C.

SU

RR

OU

ND

BB

BR

ANC

H

SEW

ER

GR

ADE

20/2

0 C

ON

C.

SUR

RO

ND

MAI

N S

EWER

Appendix A


Figure A10 : Typical Induct Vent Detail

Induct Vent

1. All dimmensions are in millimetres.

150 Min.

Inside face of Manhole

750 Min.150 Min.

Column Support

Centreline of manhole

Notes :

2. Diameter of induct vent shall be approximately 1/2of the forcemain but shall not exceed 300mm.

Appendix A


Figure A11 : Details of Household Connection to Main Sewer ReticulationPipe for V.C. Pip

CO

NC

RE

TE G

RA

DE

20/

20

FLO

W

150

THK

. GR

AD

E 2

5C

ON

CR

ETE

SU

RR

OU

ND

MAXIMUM 2000

SE

WE

R

(GR

AD

E 1

5)

MA

IN S

EW

ER

PIP

E

SH

OR

T LE

NG

TH O

F PI

PE(W

ITH

SO

CK

ET

EN

D U

ND

AM

AG

ED

)TO

BE

INS

ER

TED

INTO

EX

ISTI

NG

THIS

EN

D O

F P

IPE

TO B

E F

LUS

HED

WIT

HIN

SID

E S

UR

FAC

E O

FE

XIS

TIN

G S

EW

ER

REF

ER

TO

DE

TAIL

À'

T C A

D L

S

R

R1IN

SP

EC

TIO

N M

AN

HO

LEW

ITH

IN P

RO

PE

RTY

BO

UN

DA

RY

INS

PE

CTI

ON

MA

NH

OLE

WIT

HIN

PR

OP

ER

TY B

OU

ND

ARY

2. S

I IS

RE

QU

IRE

D T

O D

ETE

RM

INE

SO

IL C

ON

DIT

ION

AN

D R

EQU

IREM

ENT

FOR

PIL

ING

.

NO

TES

:

1. S

AD

DLE

CO

NN

EC

TIO

NS

ON

LY P

ER

MIT

TED

WH

ERE

EX

ISTI

NG

SEW

ER

IS

SLO

PE 1

%

DE

TAIL

À'

OF

GR

EATE

R D

IAM

ETE

R T

HA

N T

HE

PR

OP

OS

ED

CO

NN

EC

TIO

N P

IPE

.

2. E

NS

UR

E C

ON

NE

CTI

ON

IS D

ON

E O

NLY

ON

TH

E T

OP

HA

LF O

F TH

EE

XIS

TIN

G P

IPE

. TH

E H

OLE

SH

ALL

BE

MA

DE

AT

THE

MID

DLE

OF

THE

EX

ISTI

NG

PIP

E A

T 45

° TO

60°

AN

GLE

TO

TH

E H

OR

IZO

NTA

L.

MO

RTA

R

CO

NC

RE

TE

PIP

E

HU

NC

H(1

0 TH

ICK

NE

SS)

3. S

PEC

IAL

CO

RIN

G E

QU

IPM

EN

T TO

BE

US

ED

FO

R S

AD

DLE

CO

NN

EC

TIO

N.

1. A

LL D

IME

NSI

ON

S A

RE

IN M

ILLI

MET

RES

UN

LESS

OTH

ERW

ISE

STAT

ED

NO

TES:

-

150

CO

NC

RE

TE S

UR

RO

UN

D

TC

AD

LS

RR

1S

AD

DLE

150x

375

259

217

150

6731

019

322

418

8

225x

375

353

308

225

8031

028

422

418

8

300x

375

447

389

300

8231

835

522

418

8

150x

300

259

217

150

6725

519

317

815

1

225x

300

353

308

225

8025

528

417

815

1

150x

225

259

217

150

6722

519

314

211

3

SAD

DLE

VARIES

300 MIN.

STA

ND

ARD

WY

E O

RTE

E O

R S

AD

DLE

300 MIN.

INS

PE

CTI

ON

MA

NH

OLE

WIT

HIN

PR

OP

ER

TY B

OU

ND

AR

Y

LIM

IT O

F W

OR

KS

FOR

SE

WE

R L

INE

RO

AD

RE

SER

VE

/ BA

CK

LA

NE

RO

AD

RE

SER

VE

/ BA

CK

LA

NE

LIM

IT O

F W

OR

KS

FOR

SE

WE

R L

INE

FLOW

SE

CTI

ON

VIE

W

DE

EP C

UT

LATE

RA

L S

ER

VIC

E C

ON

NEC

TIO

N

150

Ø P

IPE

1%

MIN

. GR

AD

E T

O M

AN

HO

LE

VARIES

C L

TRE

NC

H W

IDTH

FLOW

FLOW

PLA

N

MAI

N S

EW

ER

PIP

E

C L

150

Ø P

IPE

STA

ND

ARD

WYE

OR

TE

E

R

R

PLA

N

ON

E L

EN

GTH

OF

PIP

EO

NE

LE

NG

TH O

F PI

PE

BU

ILD

ING

LO

TB

UIL

DIN

G L

OT 15

0 Ø

PIP

E

150

Ø P

IPE

MA

IN S

EW

ER

PIP

E

CO

NC

. HAU

CH

ING

RO

AD

SID

E D

RA

IN

(GR

ADE

20)

SEC

TIO

N R

- R

ON

E L

EN

GTH

OF

PIP

EO

NE

LE

NG

TH O

F PI

PE

BU

ILD

ING

LO

TB

UIL

DIN

G L

OT

MA

IN S

EW

ER

PIP

E

45°

BEN

D

SE

CTI

ON

VIE

W

LATE

RA

L S

ERV

ICE

CO

NN

EC

TIO

N

MAI

N S

EW

ER

PIP

E150

Ø P

IPE

TWO

45°

BE

ND

S

45°

BE

ND

MA

SS

CO

NC

RET

E

MA

IN S

EW

ER

PIP

E

PLA

N

MAS

S C

ON

CR

ETE

(GR

AD

E 2

0)

MAI

N S

EW

ER

PIP

E

C L

150

Ø P

IPE

150

45°

STA

ND

AR

D W

YE

OR

TEE

Appendix A


Figure A 12 : Typical Details of Concrete Thrust and Anchor BlockB B

DE

TAIL

S O

F TH

RU

ST B

LOC

K FO

R B

EN

D 4

5

AB C

TRENCH WIDTH

TRENCH WIDTH

EE

300

RE

CES

SED

INTO

S

IDE

OF

TREN

CH

AD

DIT

ION

AL

4Y12

EA

CH

FAC

E

GR

AD

E 25

/20

CO

NC

RET

E

50m

m T

HK.

GR

AD

E 1

5 C

ON

CR

ETE

BLI

ND

ING

/20

G G

AN

CH

OR

BLO

CK

ELE

VATI

ON

300

300

150

MIN. 1

000m

m

450

50m

m T

HK.

GR

ADE

15

CO

NC

RE

TE B

LIN

DIN

G/2

0

Y12

@ 3

00 C

/C

BOTH

WA

YS E

AC

H

FAC

E

NO

TES

:

1. A

LL D

IMEN

SIO

NS

AR

E IN

MIL

LIM

ETR

ES U

NLE

SS O

THER

WIS

E S

TATE

D.

2. M

ASS

CO

NC

RE

TE G

RAD

E 20

/20.

3. R

EIN

FOR

CED

CO

NC

RET

E G

RAD

E 25

/20.

4. B

LIN

DIN

G C

ON

CR

ETE

GR

ADE

15/2

0.

5. A

LLO

WA

BLE

BEAR

ING

PR

ESSU

RE

= 5

0 KN

/M .

6. T

EST

PR

ESS

UR

E FO

R T

HR

UST

BLO

CKS

IS B

ASE

D O

N 5

0mm

HEA

D O

F

WAT

ER

.

7. D

IMEN

SIO

NS

OF

THR

UST

BLO

CK

S TO

BE

INC

REA

SED

IF A

CTU

AL

BEA

RIN

G P

RE

SSU

RE

IS F

OU

ND

TO

BE

LES

S T

HAN

50

KN/M

.

8. D

IME

NS

ION

À' O

F TH

RU

ST

BLO

CK

TO

BE

ADJU

STE

D B

Y T

HE

E.R

. IF

N

ECE

SSAR

Y T

O S

UIT

TR

EN

CH

WID

TH.2

2

GR

AD

IEN

T EX

CEE

DIN

G

SC

HE

DU

LE O

F A

NC

HO

R B

LOC

K

PO

SIT

ION

OF

ANC

HO

R B

LOC

K

8 %

EVE

RY

3R

D. P

IPE

12.5

%E

VER

Y 2

ND

. PIP

E

20 %

EVE

RY

PIP

E

B

TRENCH WIDTH

D DA

C

DE

TAIL

S O

F TH

RU

ST B

LOC

K FO

R B

EN

D 1

11 4 O

R 2

21 2

SE

CTI

ON

A -

A

GR

OU

ND

LE

VEL

TRE

NC

H W

IDTH

CO

NC

. TO

BE

CAS

T A

GA

INST

OR

IGIN

AL

SOIL

SU

RFA

CE

D

CO

NC

. GR

AD

E 20

/20

DIA. OF PIPE

150

MIN

.

CO

NC

. TO

BE

CAS

T A

GA

INST

OR

IGIN

AL

SO

IL S

UR

FAC

E

D

CO

NC

. GR

AD

E 2

0/20

DIA. OF PIPE

SE

CTI

ON

C -

C150

MIN

.

C C

B

A

TRENCH WIDTH

C

DE

TAIL

S O

F TH

RU

ST

BLO

CK

FO

R B

EN

D 9

0

SE

CTI

ON

D -

D

DE

TAIL

S O

F TH

RU

ST B

LOC

K FO

R T

EE

GR

OU

ND

LE

VEL

TRE

NC

H W

IDTH

CO

NC

. TO

BE

CAS

T A

GA

INST

OR

IGIN

AL

SOIL

SU

RFA

CE

D

CO

NC

. GR

AD

E 2

0/20

DIA. OF PIPE

150

MIN

.

SE

CTI

ON

B -

B

GR

OU

ND

LE

VEL

TRE

NC

H W

IDTH

CO

NC

. TO

BE

CAS

T A

GAI

NST

OR

IGIN

AL

SO

IL S

UR

FAC

E

D

CO

NC

. GR

AD

E 2

0/20

DIA. OF PIPE

150

MIN

.

B C

A

A A

B

TRENCH WIDTH

DE

TAIL

OF

THR

US

T BL

OC

K FO

R V

ER

TIC

AL B

END

PLA

N

FF

B

TRENCH WIDTH

DE

TAIL

OF

AN

CH

OR

BLO

CK

FOR

VE

RTI

CAL

BEN

D

(AC

TIN

G U

PW

AR

D)

PLAN

CO

NC

. G

RA

DE

20/

20

SE

CTI

ON

E -

E

GR

OU

ND

LE

VEL

C

B

150

CO

NC

. G

RA

DE

20/2

0

SE

CTI

ON

F -

F

GR

OU

ND

LE

VEL

C

150

B

SE

CTI

ON

G -

G

GR

OU

ND

LE

VEL

PIP

E T

RE

NC

H W

IDTH

300

GR

OU

ND

LE

VEL

TREN

CH

WID

TH

Appendix A


Figure A13 : Typical Details of Inverted Siphons or Depressed Sewer

AA

B B

500

Ø

350

Ø

400

Ø

INLE

T C

HAM

BER

SEC

TIO

N A

- A

SEC

TIO

N B

- B

500

Ø 350

Ø

750

ØS

LID

E G

ATE

GU

IDE

(TYP

ICA

L)

INV

ER

T E

LEV

ATI

ON

OF

750

INLE

T

750

Ø

PLA

N O

F O

UTL

ET C

HAM

BER

CC

D D

500

Ø

350

Ø

400

Ø

OU

TLE

T C

HAM

BER

SEC

TIO

N C

- C

SEC

TIO

N D

- D

500

Ø

350

Ø

750

ØS

LID

E G

ATE

GU

IDE

(TYP

ICA

L)

INV

ER

T E

LEV

ATIO

NO

F 75

0 IN

LET

2000

NO

TES:

1. R

OC

KE

R P

IPE

SH

ALL

BE

600

LO

NG

FO

R S

EWE

RS

UP

TO

300

DIA

ME

TER

AN

D 9

00 L

ON

G F

OR

LAR

GE

R

DIA

ME

TER

SEW

ER

S

2. Q

UA

LIFI

ED

PE

RS

ON

TO

JU

STI

FY M

ANH

OLE

INS

TALL

ATI

ON

W

ITH

OU

T P

ILIN

G

3. A

LL D

IME

NS

ION

S A

RE

IN M

ILIM

ETE

RS

UN

LES

S O

THER

WIS

E S

TATE

D

250400

375

232

375

125

232

750

Ø

PLA

N O

F IN

LET

CH

AM

BER

Appendix A


Figure A14 : Typical Details of Receiving Manhole, Force Main andWashout Valve

150

THK.

CO

NC

RE

TE S

UR

RO

UN

D

Ø12

00 S

TAN

DA

RD

PR

ECAS

T C

ON

CR

ETE

RIN

G

Ø15

0 W

ASH

OU

T VA

LVE

TO D

RA

IN O

R S

UIT

ABL

E O

UTF

ALL

100

THK.

CAR

EFU

LLY

CO

MPA

CTE

D 2

0 M

AX.

AG

GR

EGAT

E

300

THK

. CO

NC

RET

E G

RAD

E 20

SU

PPO

RT

3 N

OS.

Ø50

H

OLE

S

300

THK.

CO

NC

RET

E G

RAD

E 20

BAS

E

THR

UST

BL

OC

K

AIR

VAL

VE

SLU

ICE

VAL

VE

APP

RO

VED

TEE

FOR

CE

MAI

N (F

OR

CE

MAI

N A

BOVE

G

RO

UN

D T

O B

E P

AIN

TED

GR

EY)

FLA

NG

E J

OIN

TS

AN

CH

OR

BLO

CK

TO S

UIT

AN

CH

OR

BLO

CK

TO S

UIT

45°

BEN

DFL

EXI

BLE

CO

UPL

ING

ELEV

ATIO

N

TYPI

CA

L FO

RC

E M

AIN

CR

OSS

ING

OVE

R C

ULV

ERT

NO

T TO

SC

ALE

AN

CH

OR

BLO

CK

TO S

UIT

FLE

XIB

LE C

OU

PLIN

G

FOR

CE

MA

IN (F

OR

CE

MAI

N A

BOVE

G

RO

UN

D T

O B

E P

AIN

TED

GR

EY)

45°

BEN

D

FLAN

GE

JO

INTS

AN

CH

OR

BLO

CK

TO S

UIT

PLA

N

TYPI

CA

L S

EW

AGE

AIR

VA

LVE

INST

ALLA

TIO

N

NO

T TO

SC

ALEØ50

AIR

VAL

VE

Ø50

SLU

ICE

VAL

VE

Ø50

D.I.

EX

TEN

SIO

N P

IEC

E TO

SU

ITW

ELD

ED T

O D

.I.

PLA

TE O

N F

LAN

GED

E

ND

OF

THE

TEE

FLA

NG

E AD

APTO

R

Ø15

0 SC

OU

R V

ALVE

AA

DE

TAIL

OF

INS

TALL

ATIO

N O

F W

ASH

OU

T VA

LVE

NO

T TO

SC

ALE

PLA

N

1000

x100

0x12

TH

K. U

NB

REA

KABL

E M

.S.

CH

EQU

ER

PLA

NT

STI

FFE

NED

BR

ACED

WIT

H

STEE

L FR

AM

E C

OM

PLE

TE W

ITH

KEY

AN

D

LOC

KIN

G G

EAR

AN

D P

AIN

TED

WIT

H

BITU

MIN

OU

S P

AIN

T IN

TER

NAL

LY A

ND

E

XTER

NAL

LYG

RO

UN

D L

EVEL

VEN

T D

UC

T TO

VE

NT

CH

AMBE

R

DE

TAIL

OF

RE

CE

IVIN

G M

AN

HO

LEN

OT

TO S

CAL

E

NO

TES:

1. A

LL P

RE

CA

ST

MA

NH

OLE

CO

MP

ON

ENTS

JO

INTS

S

HA

LL B

E F

ILLE

D W

ITH

1:3

CE

ME

NT

MO

RTA

R.

2. O

RIE

NTA

TIO

N O

F M

AN

HO

LE P

OS

ITIO

N A

CC

ES

S C

OVE

RS

AN

D C

EN

TER

LIN

E O

F S

EW

ER

S S

HA

LL B

E D

ETE

RM

INE

D O

N S

ITE

.

3. A

LL D

IME

NS

ION

S A

RE

IN M

ILLI

ME

TRES

UN

LES

S

OTH

ER

WIS

E S

TATE

D.

HE

AVY

DU

TY P

REC

AST

RC

C

OV

ER S

LAB

WIT

H 2

LAY

ERS

OF

CO

AL T

AR E

POXY

ON

U

ND

ERSI

DE

FILL

WIT

H C

EM

EN

T M

OR

TAR

1:3

HEA

VY D

UTY

DU

CTI

LE IR

ON

CO

VER

A

ND

FR

AME

(FR

AM

E BE

DD

ED O

N

CEM

ENT

MO

RTA

R)

CLA

Y B

RIC

KWA

LL (S

ING

LE C

OU

RSE

TO

BE

USE

D U

NLE

SS

OTH

ERW

ISE

SPE

CIF

IED

BY

TH

E S

O 4

CO

UR

SES

MAX

.)

RO

CK

ET P

IPE

2 LA

YER

OF

BRC

A7

45°

ANG

LE

CH

AM

BER

20 T

HK.

REN

DER

ING

IN

1:2

HIG

H A

LUM

INA

CE

MEN

T &

SAN

D

WIT

H S

LOP

E 1:

12

225

THK

. CA

ST

INSI

TU R

C

MAN

HO

LE G

RAD

E 20

WIT

H 2

LA

YER

OF

BRC

A8

CA

ST IN

SITU

CH

AMBE

R

BAS

E G

RA

DE

20

50 T

HK.

LE

AN C

ON

C.

GR

ADE

7

300Ø

SEW

ER

PIP

E20

0Ø D

.I.SP

IGO

T SO

CK

ET

JOIN

T

12 T

HK

. ALU

MIN

A LI

NIN

G

DE

TAIL

À'

DE

TAIL

À'

(ABO

VE G

RO

UN

D)

BELL

MO

UTH

Appendix A


Figure A15 : Precast Concrete Chamber (Type A ) and Details of Air Valveand Scour Valve Chamber

75

150

430

150

150380150

225

225

900

225 225900

300

150

150

150

150

75 MIN.

7575

150

900 (NTS)

630

250

580

430

5050

430

5050

50503805050

Appendix A


Figure A16 : Standard Pipe Beddings

FINAL BACKFILL(SELECTED BACKFILL)

(FOR SEWERS WITH LESS THAN 1M COVER,FORCE MAINS AND INVERTED SYPHON.)

CONCRETE SURROUND

O.D + 300

ON UNSUITABLE SOIL

COMPACTED BACKFILL

LOAD FACTOR 1.9

GREATER THAN 25.

COMPACTED DRY SOIL (FREE FROM VEGETABLE ORGANIC MATTERS &EXCAVATION/COMPACTED DRY RED EARTH/SAND/CHIPPING/STONES NOT

THE SELECTED COMPACT BACKFILL FOR VITRIFIED CLAY PIPE SHALL BE

PIPE EMBEDDED IN CAREFULLY COMPACTED 20 DIA. AGGREGATEEXTENDING HALFWAY UP TO SIDE OF THE PIPE. THE REMAINDER

CRUSHED RUN

SIDE FILL AND TOP COMPACTED CAREFULLY WITH BACKFILL.

NOTE : FOR FILLING OF TRENCHES ALONG/ACROSS

USE SAND FROM AN APPROVED SOURCE.CARRIAGEWAY, BACKFILL MATERIAL SHALL

CONCRETE ARCH

PIPE EMBEDDED IN CAREFULLY COMPACTED 20 DIA. AGGREGATE EXTENDING HALFWAY UP TO SIDES OF THE PIPE. THE REMAINDER

SIDE TO FILL AND TOP WITH MONOLITHIC PLAIN CONCRETE

O.D

+ 3

00

150

O.D + 300

SEWER PIPESEWER PIPE

CONCRETE BACKFILL

20 AGGREGATE

GRADE 20/20 CONCRETESURROUND 150 MIN

SEWER PIPE

20 AGGREGATE

LOAD FACTOR 2.8

150SELECTEDGRADE 20/20

0.25 O.D. WITH 100 MIN.

0.D + 300

300 MIN

SEWER PIPE

SPRING LINE

GROUND LEVEL

VARIES

SEWER PIPE

150 to 300mm (20mm Ø)

PIPE EMBEDMENT(CRUSHER RUN)

BEDDING

HAUNCHING

INITIAL BACK FILL

MAXIMUM TRENCH WIDTH

TABLE 1MAXIMUM TRENCH WIDTH

PIPE SIZE

(2 x 5m LONG) WHICHEVER ACHIEVED FIRST

"X' NO. OF 70 Ø BAKAU PILE (REFER TABLE ̀ A')70 Ø BAKAU PILE AT 300 C/C ALONG PIPE BAKAUPILES SHALL BE DRIVEN TO SET OR 10m DEPTH

BACKFILL & COMPACT WITHSUITABLE SOIL TO REQUIRED LEVEL

BACKFILL WITH WELL COMPACTED SOIL(HAND HELD COMPACTOR)

BACKFILL WITH SAND

CONCRETE GRADE 25 N/mm

(HAND HELD COMPACTOR)

150 THICK SANDONE LAYER OF A8 (BRC)

2

SEWER PIPE LAYING

NOTES:

1. THE BACK FILL MATERIAL SHALL BE PLACED OVER THE FULLWIDTH OF THE TRENCH AND WELL COMPACTED IN LAYERSNOT EXCEEDING 300.

2. INCREASED IN BAKAU PILES LENGTH AND NUMBER.

TABLE À'

0.50D

BEDDING FACTOR 2.8 BEDDING FACTOR 3.0BEDDING FACTOR 1.9

3. SI IS REQUIRED TO DETERMINE SOIL CONDITION AND REQUIREMENTFOR PILING.

0.50 O.D.

0.25 O.D.WITH 100 MIN.

100MIN.

0.25 O.D.WITH 100 MIN.

BACKFILL MATERIAL

LOAD FACTOR 1.9

CONCRETE CRADLE

SEWER PIPE

GRADE 20/20 CONCRETE

COMPACTED SELECTED

0.25 O.D. WITH 100 MIN.

0.D + 300

TABLE 2

300 MIN

0.25 O.D.300mm MIN.

FOR FLEXIBLE PIPESCRUSHER RUN BEDDING

32mm Ø

DETECTABLEMARKER TAPE

Appendix A


Figure A. 17 Vacuum sewage collection system

Figure A. 18 House connection

Appendix A


Figure A. 19 (a) Example of vacuum station with housed collection vessel

Appendix A


Figure A. 19 (b) Example of vacuum station with housed collection vessel

Appendix A


Figure A. 20 (a) Collection chambers with interface valves vented throughbreather pipes

Figure A. 20 (b) Collection chamber with interface valve activated by float

Appendix A


Figure A. 20 (c) Multi-valve collection chamber

Appendix A


Figure A. 21 Vacuum sewer profiles (not to scale)

Figure A. 22 Example of vacuum sewer profiles for uphill and downhilltransport (not to scale)

Appendix A


Figure A. 23 Y-branch for vacuum sewer

Figure A. 24 Method of joining crossover pipes and branch sewers tovacuum mains

Appendix A


Figure A. 25 Typical details of dry-well pump station

BLOCK3 LAYER CONC. VENTILATION

PERFORATED SLAB

DOOR

LIGHTNING ARRESTORCOPPER TYPE

CARRIERLIFTING I-BEAM C/W

WINDOW

GATE VALVE

CHECK VALVE

DRY PIT PUMPSDEWATERING PUMP

SCREENINGS COLLECTION BIN

CHEQUER PLATE

CAT LADDER

WET WELL DRY WELL

(FLOAT SWITCH)

OPENINGS

STOP LOG

INCOMING SEWER

R.C STAIRCASE TO ENGR'S DETAIL

HANDRAIL

HANDRAIL

PENSTOCK

MECHANICAL COARSE SCREEN TO NEAREST SUMPRAIN WATER DOWN PIPE

R.C GUTTER TO ENGR'S DETAIL

BRICKWALL C/W CEMENT PLASTER ON BOTH SIDES

1st. STANDBY PUMP START ALARM

2nd. STANDBY PUMP START

SUMP BWL

ALL PUMP STOP

1st.. DUTY PUMP START

2nd. DUTY PUMP START

RAMP DOWN

DNG

.I C

HA

IN G

UA

RD

.

PLAN VIEW

LOUVRES WINDOWADJUSTABLE GLASS

DOOR

DRY PIT PUMPS

R.C STAIRCASE TO ENGR'S DETAIL124 378 6 5101112 913

SPOT LIGHTCHEQUER PLATE

BRICKWALL C/W CEMENTPLASTER ON BOTH SIDES

AIR EXTRACTOR FAN

3 LAYER CONC. VENTILATION BLOCK

CHECK VALVE.

R.C STAIRCASE TO ENGR'S DETAIL.

BLOCK AT TOP AND BOTTOM LEVELCONCRETE VENTILATION

EXTRACTOR FAN

CONC. THRUST BLOCK.

654321

7

CHAIN GUARD.

181920212223

17

DN

CONC. THRUST BLOCK.

A

GATE VALVE.

1011

9816

131415

12

G.I CHAIN GUARDPENSTOCK

20191714 15 16 18 21

A

INCOMING SEWER

GRATING COVER

FORCEMAIN

3 LAYER CONC. VENTILATIONBLOCK AT TOP AND BOTTOM LEVELLIQUID RETURN FROM OTHER UNIT PROCESSESDRAIN

CONC. APRON LAID TO FALL

MECHANICAL COARSE SCREEN

OVERFLOW CHAMBER

WP

OVERFLOW PIPE DISCHARGETO MONSOON DRAIN

AT TOP AND BOTTOMLEVEL

SECTION VIEW

N.B. : The discharge level for dewatering pump shall be higher than the invert level of overflow pipe to prevent sewage from back flowing into the dry well during flooding

Appendix A


Figure A. 26 Typical detail of wet-well pump station

PENSTOCK

PLAN VIEW

R.C STAIRCASE TO ENGR'S DETAIL

16 131415 12 11 678910 5 1234

DELIVERY PIPE

GRATING COVER

STEPS

FINE SCREEN

CLEAR SPACINGS.STEEL MANUAL

CHAMBERA

OVERFLOW

INCOMING SEWER

DISCHARGE TO DRAIN OVERFLOW PIPE

S.STEEL HANDRAIL

20191817 232221 PUMP SUMP

PRIMARY SCREEN

CHECK VALVE

EXPLOSION PROOF

FLEXIBLE COUPLINGGATE VALVE

SPOT LIGHT

A

COLLECTION BIN

STEPSGRATING COVER

INFLUENT PUMP

CONC. APRON

STAND PIPEV.C.P

MECH. COARSE SCREEN

NON-EXPLOSION SPOT LIGHT

CHAMBERPRIMARY SCREEN

SECTION A-A

IL1:2

CHAMBEROVERFLOW

MANUAL COARSE SCREEN

STOP

HAND WHEELFRP STOP LOG C/W

ALARMSTART

IL OPENING

R.C WALL TO ENGR'S DETAIL

CONC. SLAB

IL

PUMP SUMPS.S PERFORATEDTROUGH

DELIVERY PIPE

LIFTING CHAIN

GUIDERAIL

HANDRAIL

MANUAL FINE SCREEN

PIPE DISCHARGETO DRAIN

OVERFLOW

CLEAR SPACING PENSTOCKFLEXIBLE COUPLING

DELIVERY PIPEGATE VALVE

CHAIN GUARDCHECK VALVE

MECH. COARSE SCREENCARRIERLIFTING I-BEAM C/W

Appendix A


Figure A. 27 Buffer Zone for Pump Station with Super Structure

Typical Section

1. 20m buffer zone shall be provided from the external edge of the P.S super-structurefence/boundary to the nearest habitable building fence/boundary as required by building by-laws. Thebuffer zone shall be sufficient to allow for pump station access and working area .

2. Non-Habitable buildings may be located within buffer zone.

3. Where the pump station is located in sensitive areas, additional buffer zone may be specified for the purpose of beutification.

Appendix A


Figure A. 28 Buffer Zone for Pump without Super Structure

1. 20m Buff er zone shall be prov ided f rom the perimeter (f ence/boundary ) of the pump station to the nearest habitable building f ence/boundary as required by building by -laws. The buffer zone shall be sufficient to allow f or pump station access and working area. 2. Non-habitable buildings may be located within the buffer zone but shall not obstruct operation, maintenance and access. 3. H is the height of the v ent pipe which shall be at least higher than roof eav es lev el for buildings up to 2 storey s high. The v ent cowl shall be at least 20m away f orm the nearest building window. 4. Where the pump station is located in sensitiv e areas, additional buff er zone may be specif ied f or the purpose beutification.

Note

G

P.S Fence

Vent

Vent

Sectional Plan

Properties Fence

H

PropertiesFence

20m (Mi )

Buffer 5m ( )Access

and Beutifician

P.S Fence

20m ( )Buffer

5m

Access and

Beutificatio

Appendix A


Figure A. 29 Buffer Zone for Pump without Super Structure

BUILDING (WOODEN OR

BUILDING (MASONRY)

GATE

POND

FIRE

PAVED

RAIL ROAD

CULVER

BRIDGE

PAVED CHANNEL AND FLOW

UNPAVED SIDE SLOPESCHAINLINK FENCEUTILITY

TELEPHONE POLE

ELECTRIC

STREET

PROPERTY, LOT OR RESERVE

SEPTIC TANKBOREHOL

PON

H

LIGHT SIDE POLE SIDE

ST

Symbols

PROVISION FOR BACKDROP FOR SEWER CONNECTIONPROVISION FOR T-JOINT FOR SEWER CONNECTION

PROPOSED MANHOLE AND SEWER IN PLAN

PROPOSED MANHOLE AND SEWER IN PROFILE

EXISTING MANHOLE AND SEWER IN PLAN

EXISTING MANHOLE AND SEWER IN PROFILE

WATER MAIN (GENERALLY 1m DEEP)

ELECTRICAL TRANSMISSION LINE OR CONDUIT (GENERALLY 1m DEEP)

TELEPHONE CONDUIT (GENERALLY 1.5m DEEP)

W

E

T

DN 375 R.C.P DN 375 R.C.P

1:80 1:72DIRECTION OF

SEW ER

PIPE

G GAS

Abbreviations

ASBESTOS CEMENT CAST

A.C.P. C.I.

CONCRET

DUCTILE DIAMETE

CENTRECONC. D.I. DIA.(ø) CRS

DRAWINEXISTINGROUND GRADE

HORIZONTA

INVERJALAN KAMPUNLORONLEFT MAXIMUMANHOLMINIMUMODIFIENUMBE

HIGH

INSIDE

DRG. EXIST. GD. GR. HORZ INV. JLN. KG. LRG. LT MAX. M.H. MIN. MOD. NO.

H.A. I.D. VERT.

N.T.S.O.D.

R.C.PRET.RTSSG.SHT.SPECSTD.SCW.STL.STA.TYP.VAR.

CH.

V.C.P

R.C.

NOT TO OUTSIDE

REINFORCED CONCRETE RETICULATION RIGHTSLOPESTREAM OR SHEETSPECIFICATIOSTANDARSTANDARD CUT-OUT STEELSTATIOTYPICAVARIEVERTICA

CHAINAG

VITRIFIED CLAY

D.M.H. DROP

REINFORCED CLASSCL. DIAMETEDIA.(ø) NOMINAL DN.

HDPE HIGH DENSITY

Appendix A

Page 126 (this pages is intend to blank) Volume 3 Malaysian SewerageIndustry Guidelines

APPENDIX B

Appendix B


Table B1 Classes of Rigid Pipe Required for Various Depth

CLA

Y P

IPE

CLA

SSES

OF

RIG

ID P

IPE

RE

QU

IRE

D F

OR

VA

RIO

US

DE

PTH

TAB

LE B

.1

Appendix B

128 (this page intended to be blank) Volume 3 Malaysian SewerageIndustry Guidelines

APPENDIX C

Appendix C


Appendix C 1 Report format for CCTV Inspection

Client :

Contact :

Position :

Road :

Town :

State :

Telephone :

Fax :

Mobile :

E- Mail :

Site :

Contact :

Position :

Road :

Town :

State :

Telephone :

Fax :

Mobile :

E-Mail :

Contractor :

Contact :

Position :

Road :

Town :

State :

Telephone :

Fax :

Mobile :

E-Mail :

Contractor :

Project-InformationProject Name : Project Number : Contact : Date :

Appendix C



Contractor :

Road: Division: Start MH:

Place: District: End MH:

Location: Tape No.: Total Length:

Purpose: Size/Shape:

Use: Material:

Catchment: Lining:

Category:

Comment:

Location details:

Code Observation Counter Photo GradeSlope

Date:

Preset:

Weather Operator

Present: Camera: Cleaned:

Section Number PLR:

Grade:

Inspection Report

Position

Job nr:

Vehicle:

MH No.

Appendix C



Contractor :

Inspection PhotosPLR :Town : Road : Date : Section Nmber :

Appendix C



To MH :

Pipe Dia. Pipe Wide Cracks or Section(mm) Length (M) Seeping Dripping Running Joints Fractures Total

N.B : When more than one defect is recorded at the same chainage, the most severe defect is counted.

Prepared By : Prepared By : Approved By : ( Qualified Person )( Name : Qualified Person & Company) ( Name : Qualified Person & Company)

Date Of Report : Date Of Report : Date :

Infiltration

DEFECT SUMMARY OF PIPE SECTIONS INSPECTION

Item Start MH End MH Material Others Comments

From MH :

Appendix C



From MH : To MH :

Item PositionNo. (M)

DEFECT SUMMARY OF PIPE SECTIONS INSPECTION

Start MH Finish MH Code Description Grade

Appendix C


Appendix C 6 ModulesSection 5 - Structural Defect Coding (Module 6A)

C CRACK 5.1 F FRACTURE 5.7 B BROKEN 5.14 H HOLE 5.16 D DEFORMED 5.18 X COLLAPSE 5.22 J JOINT 5.25CL Longitudinal 5.2 FL Longitudinal 5.7 BSV Soil Visible Beyond 5.14 HSV Soil Visible Beyond 5.16 DV Deformed Vertically 5.18 JO Joint Offset (Displaced) 5.25CC Circumferential 5.2 FC Circumferential 5.7 Defect Defect (brick) XP Pipe Collapse 5.22 JS Joint Separated (Open) 5.25CM Multiple 5.2 FM Multiple 5.7 BVV Vold Visible Beyond 5.14 HSV Vold Visible Beyond 5.16 DH Deformed 5.18 XB Brick Collapse 5.22 JA Joint Angular 5.25CS Spiral 5.2 FS Spiral 5.7 Defect Defect Horizontally (brick)

S SURFACE 5.30 S SURFACE 5.30 S SURFACE 5.30 S SURFACE 5.30 S SURFACE 5.30 S SURFACE 5.30 S SURFACE DAMAGE 5.30DAMAGE DAMAGE DAMAGE DAMAGE DAMAGE DAMAGE

SRI Roughness 5.30 SAV Aggregate Visible 5.30 SAP Aggregate 5.30 SAM Aggregate 5.30 SRV Reinforcement 5.30 SRP Reinforcement 5.30 SAP Aggregate Projecting 5.30Increased SAVM Mechanical 5.31 Projecting Missing Visible Projecting

SRIM Mechanical 5.31 SAVC Chemical Attack 5.31 SAPM Mechanical 5.31 SAMM Mechanical 5.31 SRVM Mechanical 5.31 SRPM Mechanical 5.31 SAPM Mechanical 5.31SRIC Chemical Attack 5.31 SAVZ Not Evident 5.32 SAPC Chemical Attack 5.31 SAMC Chemical Attack 5.31 SRVC Chemical Attack 5.31 SRPC Chemical Attack 5.31 SAPC Chemical Attack 5.31SRIZ Not Evident 5.32 SAPZ Not Evident 5.32 SAMZ Not Evident 5.32 SRVZ Not Evident 5.32 SRPZ Not Evident 5.32 SAPZ Not Evident 5.32

S SURFACE 5.30 S SURFACE 5.30 S SURFACE 5.30 S SURFACE 5.30 LF LINING FAILURE 5.44 LF LINING FAILURE 5.44 WF WELD FAILURE 5.56DAMAGE DAMAGE DAMAGE DAMAGE (continue)

SMV Missing Wall 5.31 SSS Surface Spalling 5.31 SZ Other 5.31 LFD Detached Lining 5.44 LFOC Overcut Service 5.44 WFL Longitudinal 5.56SMWM Mechanical 5.31 SSSM Mechanical 5.31 SZM Mechanical 5.31 SCP Corrosion 5.31 LFDE Defective End 5.44 LFUC Undercut Service 5.44 WFG Circumferental 5.56SMWC Chemical Attack 5.31 SSSC Chemical Attack 5.31 SZC Chemical Attack 5.31 (metal pipe) 5.31 LFB Blistered Lining 5.44 LFBK Buokled Lining 5.44 WFM Multiple 5.56SMWZ Not Evident 5.32 SSSZ Not Evident 5.32 SZZ Not Evident 5.32 LFCS Service Cut Shifted 5.44 LFW Wrinkled Lining 5.44 WFS Spiral 5.56

LFAC Abandoned 5.44Connection LFZ Other 5.44 WFZ Unidentified 5.56

RP POINT REPAIR 5.62 RP POINT REPAIR 5.62 (continues)

RPR Pipe Replaced 5.62 RPL Localized Pipeliner 5.62RPRD Defective 5.62 RPLD Defective 5.62RPP Patch Repair 5.62 RPZ Other 5.62

SMWZ Not Evident 5.32

Appendix C


Appendix C 6 Modules (Con’t)Section 6 - Operational and Maintenance (Module 6B)

D DEPOSIT 6.1 D DEPOSIT (continue) D DEPOSIT (continue) 6.1 R ROOTS 6.7 R ROOTS (continue) 6.7 R ROOTS (continue) 6.7 R ROOTS (continue)DA Attached 6.1 DS Settled 6.1 DN Ingress 6.1 RF Fine 6.7 RT Tap 6.7 RM Medium 6.7 RB BallDAE Encrustation 6.2 DSF Fine 6.2 DNF Fine Material 6.3 RFB Barrel 6.7 RTB Barrel 6.7 RMB Barrel 6.7 RBB Barrel

DAGS Grease 6.2 DSG Gravel 6.2 (silt & sand) RFL Lateral 6.7 RTL Lateral 6.7 RML Lateral 6.7 RBL LateralDAR Ragging 6.2 DSC Hard/Compacted 6.2 DNGV Gravel 6.3 RFC Connection 6.7 RTC Connection 6.7 RMC Connection 6.7 RBC ConnectionDAZ Other 6.2 DSZ Other 6.2 DNZ Other 6.3

I INFILITRATION 6.13 OB OBSTACLES/ OB OBSTACLES/ OB OBSTACLES/ OB OBSTACLES/ V VERMIN 6.31IW Weeper 6.13 Obstructions 6.19 Obstructions (cont) 6.19 Obstructions (cont) 6.19 Obstructions (cont) 6.19ID Dripper 6.13 OBB Brick or Masonry 6.19 OBI Object protruding 6.19 OBC Object through 6.19 OBS Built into structure 6.19 VR Rat 6.31IR Runner 6.13 through wall connection/juriction OBN Construction Debris 6.20 VC Cockroach 6.31IG Gusher 6.13 OBM Pipe Material in Invert 6.19 OBI Object wedged 6.19 OBP External Pipe Cable 6.19 OBR Rocks 6.20 VZ Other 6.31

in joint OBZ Other 6.20

Section 7 - Construction Features Coding (Module 6C)

T TAP 7.1 T TAP (continue) 7.1 T TAP (continue) 7.10 IS INTRUDING 7.8 IS INTRUDING 7.8 L LINE 7.11 L LINETF Factory Made 7.1 TB Break in/Hammer 7.2 TS Saddle 7.2 SEAL MATERIAL SEAL MATERIAL (of sewer) (of sewer)

(junction) (connection) 7.2 (connection) 7.2 ISSR Sealing Ring 7.8 ISGT Grout 7.8 (continue)TFA Active 7.2 TBI Intruding 7.2 TSI Intruding 7.2 ISSRH Hanging 7.8 ISZ Other 7.8 LL Left 7.11 LRU Right & UpTFC Capped 7.2 TBA Active 7.2 TSA Active 7.2 ISSRB Broken 7.8 LLLU Left & Up 7.11 LRD Right & DownTFD Defective 7.2 TBC Capped 7.2 TSC Capped 7.2 LLD Left & Down 7.11 LU UpTFL Leaking 7.2 TBD Defective 7.2 TSD Defective 7.2 LR Left & Right 7.11 LD Down

TFL Leaking 7.2 TSL Leaking 7.2

A ACCESSPOINT 7.13 A ACCESSPOINT 7.13 A ACCESSPOINT 7.13 A ACCESSPOINT 7.13AMH Manhole 7.13 (continue) (continue) (continue)AWA Wastewater Access 7.13 AOC Other Special 7.14 ACO Clean Out 7.14ADP Discharge Point 7.13 Chamber ACOM Machine 7.14 ACB Catch Basin 7.14ATC Tee Connection 7.13 AM Meter 7.14 ACOP Property 7.14 AEP End of Pipe 7.14

AWW Wet Well 7.14 ACOH House 7.14AJB Junction Box 7.14

Section 8 - MiscellaneousFeatures Coding (Module 6D)

M ACCESSPOINT 8.1 M MISC.FEATURES 8.1 M MISC.FEATURES 8.1 M MISC.FEATURES 8.1MCU Cmaera Underwater 8.1 (continue) (continue) (continue)MGO General Observation 8.1 MSC Shape/Size Change 8.1 MLC Lining Change 8.10 MWM Water Mark 8.2MGP General Photograph 8.1 (Sewer Dims/ MMC Material Change 8.10 MY Dye Test 8.2

Vertical/Horizontal) MSA Survey Abandoned 8.20 MYV Dye Visible 8.2MJL Pipe Joint Length 8.1 MWL Water Level 8.2 MYN Not Visible 8.2

Appendix C

136 (this page is intended blank) Volume 3 Malaysian SewerageIndustry Guidelines

Malaysian SewerageIndustry Guidelines

Suruhanajaya Perkhidmatan Air Negara (SPAN)Kementerian Tenaga, Air dan KomunikasiBlock E4/5 Parcel EPusat Pentadbiran Kerajaan62668 Putrajaya Malaysia

Tel: 03-8883 6000 Fax: 03-8889 3712http://www.ktak.gov.mye-mail : [email protected]

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