QT00129 Vol1 Final

State of Qatar -Public Works Authority Drainage Affairs

Volume 1 General Page i

1st Edition June 2005 - Copyright Ashghal

CONTENTS

FOREWORD

1 Introduction ............................................................................................................... 1

1.1 Terms of Reference ...................................................................................................... 1

1.2 Manual Development Process ...................................................................................... 1

1.3 Recommendations for Additional Study ........................................................................ 1

1.4 Manual Updating ........................................................................................................... 2

1.5 Literature/References ................................................................................................... 2

2 Planning Issues ......................................................................................................... 5

2.1 Master Plans ................................................................................................................. 5

2.1.1 Sewerage ............................................................................................................................... 5

2.1.2 Surface and Ground Water .................................................................................................... 6

2.1.3 Irrigation using TSE ............................................................................................................... 7

2.2 Allocation of Lands ....................................................................................................... 7

2.3 Statutory Undertakers ................................................................................................... 8

2.4 Infrastructure Projects ................................................................................................... 8

2.5 Catchments & Flood Plains........................................................................................... 8

2.6 Groundwater ................................................................................................................. 8

2.7 Environmental Planning ................................................................................................ 9

2.7.1 Introduction ............................................................................................................................ 9

2.7.2 Planning ............................................................................................................................... 12

2.7.3 Screening ............................................................................................................................. 12

2.7.4 Scoping ................................................................................................................................ 14

2.7.5 EIA ....................................................................................................................................... 14

2.7.6 Conclusions ......................................................................................................................... 17

3 Investigations .......................................................................................................... 18

3.1 Geotechnical ............................................................................................................... 18

3.1.1 Introduction .......................................................................................................................... 18

3.1.2 Investigation Objectives ....................................................................................................... 18

3.1.3 Desk Study and Site Reconnaissance ................................................................................. 19

3.1.4 Ground Investigation ............................................................................................................ 19

3.1.5 Extent of Ground Investigation ............................................................................................ 21

3.1.6 Field Works .......................................................................................................................... 21

3.1.7 Sampling .............................................................................................................................. 25

3.1.8 Field Tests ........................................................................................................................... 28

3.1.9 Laboratory Tests .................................................................................................................. 29

3.1.10 Reports and Interpretation ................................................................................................... 30

3.2 Hydrogeological Investigations ................................................................................... 37

3.2.1 Purpose of Investigations..................................................................................................... 37

3.2.2 Outline Methodology ............................................................................................................ 37


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3.2.3 Sources of Information ........................................................................................................ 37

3.2.4 Data Requirements: Desk Study Phase .............................................................................. 38

3.2.5 Data Requirements: Site Investigation Phase ..................................................................... 38

3.2.6 Notes on Site Investigation Techniques .............................................................................. 39

3.3 Surveys ....................................................................................................................... 40

3.3.1 Types of Survey ................................................................................................................... 41

3.4 Operating Data ........................................................................................................... 43

3.4.1 Pumping Stations ................................................................................................................ 43

3.4.2 Sewage Treatment .............................................................................................................. 44

3.4.3 Sewerage ............................................................................................................................ 44

3.4.4 Surface Water/Hydrology .................................................................................................... 44

3.5 Asset Condition ........................................................................................................... 44

3.6 Meteorology ................................................................................................................ 44

3.6.1 Introduction .......................................................................................................................... 44

3.6.2 Climate Overview ................................................................................................................ 45

3.6.3 Rainfall ................................................................................................................................. 45

3.6.4 Other Climatological Variables ............................................................................................ 49

3.6.5 Wind Speed and Direction ................................................................................................... 49

3.7 Environmental Investigations ...................................................................................... 53

3.7.1 Introduction .......................................................................................................................... 53

3.7.2 Strategic Environmental Assessment (SEA) ....................................................................... 53

3.7.3 EIA Investigations ................................................................................................................ 53

4 Design Process ........................................................................................................ 55

4.1 Background Information .............................................................................................. 55

4.1.1 Existing Services and Utilities ............................................................................................. 55

4.1.2 Services Hierarchy .............................................................................................................. 55

4.1.3 Site Investigations ............................................................................................................... 55

4.1.4 GIS / AIS .............................................................................................................................. 56

4.1.5 QNBS/QCS .......................................................................................................................... 56

4.2 Ground Conditions ...................................................................................................... 56

4.2.1 Topography & Regional Geology ........................................................................................ 56

4.2.2 Geology of the Dammam Formation ................................................................................... 59

4.2.3 Hydrogeology ...................................................................................................................... 61

4.2.4 Summary of Relevant Conditions ........................................................................................ 62

4.3 Construction Materials ................................................................................................ 62

4.3.1 Materials Selection .............................................................................................................. 62

4.3.2 Structures ............................................................................................................................ 69

4.3.3 Quality Control and Quality Assurance ............................................................................... 71

4.4 Design Standards, Procedures and Calculations ....................................................... 72

4.5 Standard Drawings ..................................................................................................... 72

4.6 Building Permits .......................................................................................................... 73

4.6.1 Opening a Building Permit File ............................................................................................ 73

4.6.2 Initial DC 1 Approval ............................................................................................................ 73

4.6.3 Utility Approvals ................................................................................................................... 73


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4.6.4 Final DC1 Approval .............................................................................................................. 74

4.6.5 DC 2 Approval ...................................................................................................................... 74

4.6.6 Building Permit ..................................................................................................................... 74

4.7 Environmental Design ................................................................................................. 74

4.8 Tendering and Contract Procedures ........................................................................... 75

4.8.1 Professional Service Agreement ......................................................................................... 75

4.8.2 Conventional Construction Contracts .................................................................................. 76

4.8.3 76

4.8.4 Design and Construct Construction Contracts ..................................................................... 76

4.8.5 Material Supply Contracts .................................................................................................... 76

4.8.6 Hybrid Contracts .................................................................................................................. 77

4.8.7 Work Carried Out Under Work Order Agreements .............................................................. 77

4.9 Health and Safety and Security .................................................................................. 77

4.9.1 Policy Statement .................................................................................................................. 77

4.9.2 Accident Reporting ............................................................................................................... 79

4.9.3 Training ................................................................................................................................ 79

4.9.4 Site Safety Meetings ............................................................................................................ 81

4.9.5 Enforcement Policy .............................................................................................................. 82

4.10 CDM Best Practice...................................................................................................... 83

4.10.1 Introduction .......................................................................................................................... 83

4.10.2 Earliest Involvement ............................................................................................................. 83

4.10.3 Co-ordination ....................................................................................................................... 83

4.10.4 Preparing the Design ........................................................................................................... 83

4.10.5 Health and Safety Plan ........................................................................................................ 84

4.10.6 Health and Safety File .......................................................................................................... 85

5 Reporting Systems .................................................................................................. 86

5.1 General ....................................................................................................................... 86

5.1.1 Quality Control ..................................................................................................................... 86

5.1.2 Format of Documents .......................................................................................................... 86

5.2 Sketch Stage .............................................................................................................. 90

5.2.1 Structure/Content of Report ................................................................................................. 90

5.2.2 Programme .......................................................................................................................... 91

5.2.3 Design Enquiry Status ......................................................................................................... 91

5.2.4 Available Information ........................................................................................................... 91

5.2.5 Investigations ....................................................................................................................... 91

5.2.6 Land Use .............................................................................................................................. 91

5.2.7 Design Criteria ..................................................................................................................... 91

5.2.8 Options ................................................................................................................................. 91

5.2.9 Recommendation ................................................................................................................. 91

5.2.10 Appendices .......................................................................................................................... 91

5.2.11 Typical Drawings .................................................................................................................. 92

5.3 Preliminary Stage Report ........................................................................................... 92

5.3.1 Structure/Content of Report ................................................................................................. 92


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5.4 Detail Design and Tendering Stage ............................................................................ 93

5.5 Documentation ............................................................................................................ 93

5.5.1 Drawings .............................................................................................................................. 93

5.5.2 Specification ........................................................................................................................ 93

5.5.3 Bill of Quantities................................................................................................................... 94

5.6 Engineering Report ..................................................................................................... 94

5.7 Supplementary Reports .............................................................................................. 95

6 Checking Systems ................................................................................................... 96

6.1 Project Quality Plan .................................................................................................... 96

6.2 Stage Approvals ......................................................................................................... 97

6.3 References and Information updating ......................................................................... 97

6.4 Progress Reporting ..................................................................................................... 97

7 Operation and Maintenance.................................................................................... 99

7.1 Normal Operations ...................................................................................................... 99

7.1.1 Operational Objectives and Priorities .................................................................................. 99

7.1.2 Management and Control of Operations ........................................................................... 100

7.1.3 Operating Procedures, Schedules and Organisation ........................................................ 101

7.1.4 Cost Control and Operational Efficiency ........................................................................... 101

7.2 Routine (Scheduled) Maintenance ........................................................................... 101

7.2.1 Definition of Scheduled Maintenance ................................................................................ 102

7.2.2 Classification of Routine Maintenance Tasks.................................................................... 102

7.2.3 Method Statements on Each Activity and Sub-Activity ..................................................... 103

7.2.4 Organisation and Control of Scheduled Maintenance ....................................................... 103

7.2.5 Inspection, Quality Control and Follow-Up ........................................................................ 104

7.2.6 Maintenance and Inspection of Safety/Rescue Equipment............................................... 104

7.3 Non-Scheduled (Non-Routine) Maintenance ............................................................ 105

7.3.1 Definition of Non-Scheduled Maintenance ........................................................................ 105

7.3.2 Classification of Non-Scheduled Maintenance Tasks ....................................................... 105

7.3.3 Identifying the Need for Non-Scheduled Maintenance ...................................................... 105

7.3.4 Management of Non-Scheduled Maintenance .................................................................. 105

7.3.5 Control of Costs and Quality ............................................................................................. 106

7.3.6 Inspection and Follow-Up .................................................................................................. 106

7.4 Emergency Procedures ............................................................................................ 106

7.4.1 Definition and Classification of Emergencies .................................................................... 106

7.4.2 Establishment of Emergency Response Plans/Procedures .............................................. 107

7.4.3 Emergency Plant and Equipment ...................................................................................... 108

7.4.4 Public Health and Environmental Considerations ............................................................. 108

7.4.5 Safety Considerations ....................................................................................................... 109

7.4.6 Feedback and Optimising Emergency Response ............................................................. 109

7.4.7 First Aid Arrangements and Emergency Procedures ........................................................ 109

7.5 Spare Parts and Equipment ...................................................................................... 109

7.5.1 Targets and Objectives ..................................................................................................... 110

7.5.2 Spare Parts Availability...................................................................................................... 110


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7.5.3 Storage Facilities ............................................................................................................... 110

7.5.4 Inventory Control and Stock Management Procedures ..................................................... 110

7.6 Records..................................................................................................................... 111

7.6.1 Operational Records .......................................................................................................... 111

7.6.2 Records of Scheduled Maintenance .................................................................................. 111

7.6.3 Records of Non-Scheduled Maintenance .......................................................................... 112

7.6.4 Records of Emergencies .................................................................................................... 112

7.6.5 Recommendations for Reporting of Operation & Maintenance ......................................... 112

7.6.6 Records of Existing Assets, Including GIS and Electronic Media ...................................... 112

7.6.7 Procedures for Maintenance and Updating of Asset Databases ....................................... 112

7.6.8 Verification, Updating and Maintenance of ‘As-Built’ Drawings, Documents and Manuals113

7.7 Capacity Review ....................................................................................................... 113

7.7.1 Guidelines for Monitoring and Reporting of Operational Capacity .................................... 113

7.7.2 Measurement of Pump Performance Against Design ....................................................... 113

7.7.3 Comparison of System/Part of Actual System Against Design Capacity .......................... 114

8 References ............................................................................................................. 115

APPENDICES

Appendix 1 - Sample Calculation Sheets, Forms, HARA & Report Page Layout

Appendix 2 - Programmes

Appendix 3 - Drawings

Appendix 4 -Tender Procedure Flowchart

Appendix 5 - Industrial Waste Application

Appendix 6 - Soil and Rock Descriptions

Appendix 7 - Sample Letters


Page vi Volume 1 General June 2005 - Copyright Ashghal

FOREWORD

This Manual is the sole property of the Drainage Affairs (DA) of the Qatar Public Works Authority. It was produced

by Hyder Consulting (ME) Ltd under a Project Service Agreement (PSA), on behalf of the Qatar DA in December

2003.

This is the first of 8 Volumes, as listed below:

• Volume 1 - General

• Volume 2 - Foul Sewerage

• Volume 3 - Surface and Groundwater Drainage

• Volume 4 - Treated Sewage Effluent

• Volume 5 - Sewage Treatment Works

• Volume 6 - CAD Manual

• Volume 7 - Standard Drawings

The Manual is intended for use as a guide to good practice in the design of work on behalf of, and for adoption by

the DA. It is intended to be used by consulting engineers in order to produce a degree of uniform quality and

similarity for future infrastructure developments throughout Qatar.

The content of the Manual has been compiled by a panel of specialists based upon their collective individual

experiences, and in close consultation with DA staff.

The first issue of the Manual is available for general circulation in paper format. Digital master copies will be

retained by the DA. A web-based version of the Manual will be compiled subsequent to the successful launch of

the first issue. Any enquiries regarding this Manual should be directed to the Head of Consultancy Services

Division, Qatar Drainage Affairs. It is intended that the Manual will be reviewed by the DA after the first year of

implementation in June/July 2005.

i Standards

This Manual should be used in accordance with, or as a supplement to the relevant standards, codes, papers and

other documents, as categorised into the three categories below.

A. Contract Documents

B. Local Technical Regulations

C. Technical Codes and Papers

Please note, that the reader should always check with the relevant authority for new standards or revisions of

existing documents pertaining to the task at hand.

A. Contract Documents

The following are examples of relevant contract documents (not exhaustive):

• General Conditions of Contract, Prepared by the Ministry of Public Works;

• Professional Service Agreement General Conditions of Engagement 1984;

• Conditions on Contract Governing the Supply of Materials;

• Conditions of Contract for Design and Build Projects.


Volume 1 General Page vii


B. Local Technical Regulations

The following are examples of applicable technical regulations (not exhaustive):

• The Qatar National Building Specification ("QNBS") published by the Ministry of Public Works, including all

revisions issued by the Ministry of Industry & Public Works and the Public Works Authority(Qatar Contract

Specification (“QCS”), is currently undergoing revision and not preferred by DA);

• The Survey Manual prepared by the Survey Section of the Ministry of Public Works;

• The Qatar Traffic Manual prepared by the Ministry of Public Works;

• The Traffic Control at Road Works Manual issued by the Ministry of Industry & Public Works;

• Rules, Regulations and Code of Practice for Design and Installation of Air Conditioning, Heating, Ventilation

& Refrigeration (ACHVR) Systems for Government Buildings, 2nd Edition, 1989, prepared by Electricity

and Water Department (MEW);

• Regulations for the Installation of Electrical Wiring by Qatar National Telephone;

• The Regulations for the Installation of Electrical Wiring, Electrical Equipment and Air Conditioning

Equipment, sixth re-issue dated January 1992 prepared by the Ministry of Electricity and Water, PO Box

41, Doha;

• Any current and relevant regulation, notice or circular issued by the Public Works Authority(including the

previous Ministry of Public Works and the previous Ministry of Industry and Public Works), the Ministry of

Electricity and Water or the appropriate local Municipality prior to the date of the letter of invitation to

Tender;

• State of Qatar Law Number (8);

• State of Qatar Law No. 30 of 2002 and all subsequent amendments concerning “The Environment and

Natural Resources Protection” – Articles 6, 17, 19 & 35 obtainable form Government House.

C. Technical Codes and Papers

The following are examples of applicable technical codes/papers (not exhaustive):

• The Code of Practice and Specification for Road Openings in the Highway prepared by the Ministry of

Industry & Public Works;

• The Guide for Civil Users of Explosives in Qatar prepared by the Ministry of Public Works.

ii Authorities

The following utility/planning authorities should be contacted as appropriate for guidance, approvals and applicable

standards/regulations/codes of practice, pertaining to the design task being undertaken.


Page viii Volume 1 General June 2005 - Copyright Ashghal

Utility/Planning Authorities

The Director of Drainage Affairs Public Works Authority

PO Box 23337 Doha

The Director of Roads Affairs

Ministry of Municipal Affairs and Agriculture PO Box 22188

Doha

The Director of Building Engineering Department Public Works Authority

PO Box 22188 Doha

The Director of Agricultural Development Department Public Works Authority

PO Box 22188 Doha

The Head of Mapping & Positioning Services

Centre for GIS Public Works Authority

PO Box 22188 Doha

The Director of Electricity Networks Department

Qatar General Electricity & Water Corporation PO Box 41

Doha

The Director of Water Networks Department Qatar General Electricity & Water Corporation

PO Box 41 Doha

The Director of Programmes & Planning

Qatar General Electricity & Water Corporation PO Box 41

Doha

The Manager of External Planning Division Q-Tel

PO Box 217 Doha

Engineering Manager of Oil & Gas Operations Qatar Petroleum

PO Box 70 Doha

The Director of Planning Department

PO Box 3843 Doha


Volume 1 General Page ix


The Director of Land Information Centre PO Box 23999

Doha

The Director of Land Acquisition Department PO Box 2199

Doha

The Director of Land Department PO Box 2199

Doha

The Director Supreme Council for the Environment and Natural Resources

PO Box 7634 Doha

The Director of Department of Industrial Development

Ministry of Energy & Industry PO Box 2599

Doha

REGULATING AUTHORITIES

The Chairman General Tenders Committee

Public Works Authority Doha - Qatar

The Chairman

Limited Tenders Committee Public Works Authority

Doha - Qatar

The Chairman Small Tenders Committee Public Works Authority

Doha - Qatar

State Audit Bureau PO Box 2466

Doha

Department of Legal Opinions & Contracts PO Box 917

Doha

iii Qatar National Height Datum (QND) and Qatar National Grid

The Qatar National Height Datum is referred to as the Qatar National Datum 1995 (QND95). Both QND and

the Qatar National Grid are regulated by:

The Head of Mapping & Positioning Services Centre for GIS

Public Works Authority PO Box 22188, Doha


Page x Volume 1 General June 2005 - Copyright Ashghal

Details of benchmarks and co-ordinates of survey stations throughout Qatar can be obtained from the

Centre for GIS (cGIS).

iv Definitions

The following definitions apply to terms used throughout Volumes 1 – 8 of this Manual

Accuracy -is the extent to which a given measurement agrees with the standard value

required for that measurement, or the level of error on measuring instruments.

Aeration -is the addition of oxygen to wastewater.

Aerobic -respiration is respiration in the presence of oxygen.

Ammonia (NH3) -protein breakdown product common in wastewater

Anaerobic -respiration is respiration in the absence of oxygen.

Approved -terms such as “approved”, “approved by”, “to the approval”, “as directed” and the

like refer always to approval or directions given by the Engineer in writing.

Backfill -material used to fill pipe trench to formation level.

Bacteria -single celled organisms, which play a part in the breakdown of organic matter.

Bar screen -catches large objects prior to entering pumping stations, water treatment and

wastewater treatment processes.

Bedding / Bed and Surround -granular material used to bed pipes in trenches.

Belt press -device for mechanical dewatering of sludge.

Bioassays -tests on biota which can be used to determine both the short and long-term impact

of schemes.

Biochemical Oxygen Demand -(BOD) is the quantity of oxygen used by micro-organisms in the aerobic demand

stabilisation of wastewater. It is a measure of the amount of organic matter in the

wastewater.

Catchpit -roadside drainage appurtenance designed to collect silt (also known as silt trap).

Centrifugal separation -is a method of concentrating suspended solids.

Chloramines -product of chlorine and ammonia sometimes used for disinfection.

Chlorination -most common method of disinfection.

Chlorine dioxide (CO2) -less common disinfectant.

Client -the Municipality, Department, Agency or individual for whom the Project is being

undertaken and to whom the hand over of the final product will be made.

Chemical Oxygen -the amount of chemically oxidizable material present in the wastewater. Demand (COD)


Volume 1 General Page xi


Coliform bacteria -indicator organisms for faecal contamination in wastewater

Comminutor -mechanism used to shred suspended material in wastewater.

Contract -legally binding agreement.

Contractor -the company or organisation responsible for the construction of the Works under

the terms of the contract.

Cover -depth of fill above pipe, or thickness of concrete surround to reinforcement.

Crown -top of pipe.

Datum -reference level.

Design Flow -flow used for design of facilities such as Sewage Treatment Works (STW) (also

called FFT), for sewer and stormwater (SW) drainage pipes.

Density -mass per unit volume.

Digester -wastewater treatment module to promote breakdown of settled sludge.

Detention time -the time which elapses between wastewater entering and leaving a tank.

Dilution -is the mixing of a strong concentration of solution with water or other liquid to

produce a weaker concentration.

Disease -health disorder caused by pathogens, which can be associated with wastewater.

Disinfection -deactivation of viable pathogens.

DO (Dissolved Oxygen) -refers to the amount of dissolved oxygen in water expressed in milligrams per litre.

Drain -pipe conveying surface or ground water.

Drawings -drawings included in the Project Documentation.

Drying beds -type of facility using evaporation for dewatering digested sludge.

Dry Weather Flow (DWF) -sewer base-flow during dry periods with no inflow due to rainfall.

Efficiency -actual performance expressed as a percentage of theoretical maximum.

Effluent -outflow from a sewer or treatment process.

Engineer -the Director of Drainage Affairs, Director of Roads Affairs, or the Director of

Building Engineering, as appropriate, unless specified otherwise in the Project

Documentation.

Environmental Protection -standards set by the Supreme Council for the Environment and Natural Reserves (SCENR) for application under the Qatar Environmental Law.

Evaporation (Pan) -measure of water loss to atmosphere from large water surfaces (not to be confused by evaporation (piche) referring to plant evaporation).

Extended aeration plants -type of activated sludge process.

Flow to Full Treatment (FFT) -design flow at the STW, commonly three times DWF in Qatar.

Formation -Founding level for road construction, or top of excavation level.


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F/M -food to micro-organism ratio.

Facultative bacteria -are able to break down organic matter in the presence or absence of oxygen.

Feasibility -is the viability or likelihood of an event or process taking place.

Fixed media filters -use micro-organisms attached to a medium to treat wastewater.

Government -government of the State of Qatar.

Granular sub base -road construction material.

Grease -long chain hydrocarbons common in wastewater from cooking processes.

Grinder/Macerator pump -comminutor (see above).

Grit -dense, inorganic material in wastewater.

Guarantee -is a written assurance.

Hydraulic loading -is the volume of wastewater treated per unit time.

Hypochlorite -oxidising agent used for disinfection.

Invert -lower inside surface level of pipe, or top of slab level.

Kinetics of growth -conditions for microbial treatment of wastewater.

Mixed Liquor Suspended Solids (MLSS) -amount of total suspended solid material (organic and inorganic). Mixed Liquor Volatile Suspended Solids (MLVSS) -amount of organic material suspended in the mixed liquor sample.

Nocardia -bacteria which are a major cause of foaming in activated sludge plants

Organic Loading -amount of BOD applied to a treatment plant.

O.U.R. (Oxygen Uptake

Rate) -rate at which oxygen is consumed by living organisms in the waste stream.

Oxidation Ditch -suspended growth treatment process for wastewater, commonly with large specific

surface area and surface aeration.

Ozone (O3) -strong oxidising agent sometimes used for disinfection.

Package Plant -small treatment plant manufactured in modules.

Peak Flow -maximum value of flow at a point in a sewer or other system. Design flows in pipes

are generally taken as the peak flow.

Pipe Full Flow -pipe capacity with no surcharge.

pH -measure of acidity on a scale of 1-7.

Power -measure of energy consumption or output, expressed as a total or rate.

Precision -degree of accuracy.


Volume 1 General Page xiii


Pre-treatment -is the first phase of the wastewater treatment process. It usually includes

screening and grit removal or in the case of small plants, screening and shredding

the sewage.

Primary Treatment -settlement stage of the wastewater treatment process in a conventional STW

following pre-treatment.

Project Documentation -all documents associated with and applicable to the Project Contract.

Pumps -are mechanical devices that impart additional pressure head at a given flow.

Pumps are most efficient at only one pressure and flow and are rated accordingly.

Rotating Biological

Contactor (RBC) -fixed film bioreactor used in wastewater treatment.

Recirculation -proportion of effluent from a treatment which is recycled to improve treatment.

Sequencing Batch

Reactor (SBR) -activated sludge system which operates sequentially as opposed to continuously.

Sedimentation Chamber -settlement tank.

Seeding -is the process of inoculating the influent with micro-organisms usually for removal

of contaminants.

Septic -anaerobic.

Septic Tank -septic tanks treat sewage by anaerobic means and are installed with soakaways or

tile beds. They are installed primarily for private homes. In Qatar the term is also

used to include cesspits, which do not have soakaways and require emptying

regularly by tanker.

Settling -process in which denser material is separated by gravitation.

Sewage -domestic or industrial wastewater.

Sewer -pipe which conveys sewage.

Sewerage -refers to complete sewer system and appurtenances.

Site -the land allocated for Works to be constructed.

Sludge -is a semi-solid material produced during wastewater treatment processes.

Sludge consists of mostly of dead micro-organisms and inorganic matter.

Sludge – Returned/Activated -Secondary sludge returned to the head of the process to seed influent.

Soakaway -facility for dispersion of water to soil strata, primarily for surface water dissipation,

but also associated with septic tanks.

Soffit -underside of pipe or slab.

Solubility -is the amount of a substance which will dissolve in water.

Specific Gravity -density relative to water.

Supernatant -clear fluid decanted from the top of tanks


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Suspended Solids -Insoluble substances suspended in water.

SVI (Sludge Volume Index) -measure of sludge settleability formally defined as "the volume in millilitres

occupied by 1gm of activated sludge after settling the aerated mixed liquor for 30

minutes".

Tertiary Treatment -polishing stage in wastewater treatment to further improve treatment and remove

nutrients.

Time of Concentration -time required for surface water flow to reach a specific point downstream of entry in

SW drainage system.

Time of Entry -time required for surface water flow to enter SW drainage system.

Toxins -poisonous compounds.

Tricking Filter -are a type of fixed-media filter used in wastewater treatment.

Total Suspended Solids

(TSS) -measure of insoluble content of wastewater.

Ultraviolet (UV) Light -is light beyond the violet end of the visible spectrum, used for wastewater

disinfection.

Valve -flow control device used to limit or isolate flow.

Washout -low point of a pressure pipeline equipped with a tee/branch pipe and isolating

valve, to enable draining of the main and flushing of solids.

Washout -occurs when a great deal of stormwater flows into a treatment plant. Micro-

organisms, sludge, and wastewater are forced through the plant and out into a river

or stream before being properly treated.

Wastewater -domestic and industrial sewage.

Wet well -pumping station chamber receiving inflow.


Volume 1 General Page xv


v Abbreviations

A. Drainage Affairs Abbreviations

The following definitions refer to Qatar Drainage Affairs Divisions/Areas.

Abbreviation Description

DD Designs Department

DA Drainage Affairs

DODA Director of Drainage Affairs

AMoDD Acting Manager of Designs Department

AMoMD Acting Managerof Maintenance Department

AMoPD Acting Manager of Projects Department

AMoQ&SD Acting Manager of Quality and Safety Division

MMAA Ministry of Municipal Affairs and Agriculture

MD Maintenance Department

PD Projects Department

Q&SD Quality and Safety Department

B. Other Departments/Organisations Definitions

The following definitions refer to Qatar Departments/Organisations other than the Drainage Affairs.


BA Building Affairs

CEBA Contract and Engineering Business Affairs

CTC Central Tenders Committee

DLOC Department of Legal Opinion and Contracts

cGIS Centre for Geographic Information Systems

PDS Prime Document Storage

QGEWC Qatar General Electricity and Works Company

QP Qatar Petroleum

Q-Tel Qatar Telecommunications

RA Roads Affairs

SAB State Audit Bureau

SCENR Supreme Council for the Environmental and Natural Reserves

TAC Tenders and Auction Committee


Page xvi Volume 1 General June 2005 - Copyright Ashghal

C. Technical Definitions

The following definitions relate to technical abbreviations found throughout Volumes 1-8 of this Manual.


% Percent – i.e. 50/100 = 50%

°C Degrees Celsius

A/C Air Conditioner/Conditioning

AASHTO American Association of State Highway and Transportation Officials

ABS Acrylonitrile Butadiene Styrene

AC Alternating Current

AC Asbestos Cement

ACB Air Circuit Breaker

AIS Asset Information System

AMCA Air Movement Conditioning Association

ANSI American National Standards Institute

APIS American Petroleum Institute Specification

ARF Areal Reduction Factor

ACRI Air Conditioning and Refrigeration Institute

ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers

ASTM American Society for Testing and Materials

BOD Biological Oxygen Demand

BS / BSI British Standards / British Standards Institute

C&CA Cement and Concrete Association

CBGF Cement Bound Granular Fill

CESMM3 Civil Engineering Standard Method of Measurement, 3rd Edition, 1991

CFD Computational Fluid Dynamics

cGIS Central Geographical Information System

CI Cast Iron

CIBSE Chartered Institution of Building Services Engineers

CIRIA Concrete Industry Research and Information Association

COD Chemical Oxygen Demand

COSHH Control of Substances Hazardous to Health

CPU Central Processing Unit

CPVC Chlorinated Polyvinyl Chloride

CS Concrete Society

CW Constructed Wetlands

dBa Decibel Amperes (electrical)


Volume 1 General Page xvii



DC Direct Current

DCS Distributed Control Systems

DA Drainage Affairs of the Public Works Authority

DI Ductile Iron

DICL Ductile Iron Concrete Lined

dia/diam Diameter

DO Dissolved Oxygen

DOL Direct on Line

DWF Dry Weather Flow

dwg Drawing

EC European Community

EFA Environmental Flooding Areas

EGL Existing Ground Level

EIA Environmental Impact Assessment

EIS Environmental Impact Study

ELCB Earth Leakage Circuit Breakdown

ELV Extra Low Voltage

EPDM Ethylene Propylene Rubber

FGL Finished Ground Level

FLC Full Load Current

F/M Food to Micro-organism Ratio

GGBS Ground Granulated Blastfurnace Slag

GI Ground Investigation

GIR Ground Investigative Report

GIS Geographical Information System

GL Ground Level

GPS Geographical Positioning System

GRE Glass Reinforced Epoxy

GRP Glass Reinforced Plastic

GSB Granular Sub Base

GL Ground Level

GWL Groundwater Level

H2S Hydrogen Sulphide

HCME Hyder Consulting Middle East Ltd

H&S Health and Safety


Page xviii Volume 1 General June 2005 - Copyright Ashghal


HV High Voltage (exceeding 650 volts between conductor or between any conductor and

earth)

HVAC Heat, Ventilation & Air Conditioning

I/O Input/Output

ICE Institution of Civil Engineers

IDF Intensity Frequency Duration

IEE Institution of Electrical Engineers

IEE Regulations The Institution of Electrical Engineers Regulations for Electrical Installations

ISO International Standard Organisation

KSM Kuwait Stormwater Master Plan

KVA kilo Volt Ampere

LAN Local Area Network

LCD Liquid Crystal Display

LED Light Emitting Diode

LRA Lock Rotor Current

Lux The metric unit of measure for illuminance of a surface (Light intensity)

LV Low Voltage (exceeding 50 volts but not exceeding 250 volts between any conductor and

earth)

M&E Mechanical & Electrical

Mbgl Metres below ground level

MCB Main Circuit Breaker

MCC Motor Control Centre

ME Middle East

MLSS Mixed Liquor Suspended Solids

MLVSS Mixed Liquor Volatile Suspended Solids

MMAA Ministry of Municipal Affairs and Agriculture

MCCB Moulded Case Circuit Breakdown

MS Mild Steel

MTU Motor Terminal Unit

MV Medium Voltage (exceeding 250 volts but not exceeding 650 volts between any conductor

and earth)

N/C Normally Closed

N/O Normally Open

NDM Non Destructive Methods (e.g. trenchless)

Ne Not exceeding

NH3 Ammonia

No. Number


Volume 1 General Page xix



NPSH Net Positive Suction Head

NPT National Pipe Thread

Nr Number

NRV Non Return Valve

O3 Ozone

OEL Occupational Exposure Limit – e.g. to hydrogen sulphide gas.

OHSA Occupational Health and Safety Act

O&M Operations and Maintenance

OPC Ordinary Portland Cement

O.U.R Oxygen Uptake Rate

PC Personal Computer

PF Power Factor

PFA Pulverised Fuel Ash

PH Measure of acidity, units are pH on a scale of 1-7

PID Proportional, Integral, Derivative

PIMP Percentage Impermeable

PLC Programmable Logic Controller

PLSW Paper Lead and Steel Wire

PM Project Manager

Ppb Parts per Billion

Ppm Parts per Million

PS Pumping Station

PSA Professional Services Agreement

PSTN Public Switched Telephone Network

PTTA Partially Type Tested Assembly

PVC Polyvinyl Chloride

PVC-U Unplasticised Polyvinyl Chloride, also referred to as uPVC

QA Quality Assurance / Assured

QC Quality Control

QGEWC Qatar General Electricity and Water Corporation

QHDM Qatar Highways Design Manual

QNBS Qatar National Building Specification

QND / QNHD Qatar National Datum / Qatar National Height Datum

QR Qatar Riyals

Q-Tel Qatar Public Telecommunications Corporation

R Radius

RBC Rotating Biological Contactor

RC Reinforced Concrete


Page xx Volume 1 General June 2005 - Copyright Ashghal


RPM Rotations Per Minute

Rpm Revolutions Per Minute

RTU Remote Telemetry Unit

SAR Sodium Absorption Ratio

SBR Sequencing Batch Reactor

SCADA Supervisory Control and Data Acquisition

SKVA Starting kilo Volt Ampere

SLS Serviceability Limit State

SMS Short Message Service

SNMP Simple Network Management Protocol

SPN Single Phase and Neutral

SRC Sulphate Resisting Cement

SRPC Sulphate Resisting Portland cement

SS Stainless Steel

STP Sewerage Treatment Plant

STW Sewerage Treatment Works

SVI Sludge Volume Index

SW Surface Water or Stormwater

SWL Safe Working Load

TDH Total Dynamic Head

TDS Total Dissolved Solids

TSE Treated Sewage Effluent

TSS Total Suspended Solids

TTA Type Tested Assembly

TTW/TTP Tertiary Treatment Works/Tertiary Treatment Plant

TWL Top Water Level, e.g. of a tank or wet-well

UAE United Arab Emirates

ULS Ultimate Limit State

UPS Uninterrupted Power Supply

uPVC Unplasticised Polyvinyl Chloride, also referred to as PVC-U

UV Ultra Violet

v/v Concentration volume/volume

Vac Volt alternating current

VC Vitrified Clay

Vdc Volt direct current

VDU Visual Display Unit

VFD Variable Frequency Drive

VSD Variable Speed Drive

VT Voltage Transformer


Volume 1 General Page xxi



WG Wire Gauge

WHO World Health Organisation

WIS Water Industry Specification

WRC Water Research Centre, UK

XML Extensible Markup Language

vi Units and Dimensions

The units used on all projects shall be SI units only, as per the table below

Multiplication factor prefix Symbol

1 000 000 000 000 = 1012 tera T

1 000 000 000 = 109 giga G

1 000 000 = 106 Mega M

1 000 = 103 Kilo k

100 = 102 hectot h

10 = 101 dekab da

0.1 = 10-1 decib d

0.01 = 10-2 centib c

0.001 = 10-3 milli m

0.000 001 = 10-6 micro µ

0.000 000 001 = 10-9 nano n

0.000 000 000 001 = 10-12 pico p

0.000 000 000 000 001 = 10-15 femto f

0.000 000 000 000 000 001 = 10-18 atto a


Volume 1 General Page 1


1 Introduction

The Drainage Affairs (DA) Design Manual comprises

eight separate volumes. The coverage of each is

designed to reflect the organisational structure of the

DA.

The content in some areas of the Manual, such as

Volumes 2 and 3 (foul and surface water

respectively) is repeated. This is because the

different specialisms are covered by different

sections within the DA. Separate volumes of the

Manual are available corresponding to the different

administrative sections of DA, and are intended to

be complete for the particular section, or provide

references to relevant sections of other volumes

where this is not possible. For this reason, material

is repeated in some volumes in order to provide a

source of information for each department that will

be, on the whole, independent of other volumes.

References to other volumes are provided where

appropriate however.

The Manual is for use by Design Consultants in

developing new infrastructure for the DA. The

Manual will be controlled and administered by the

DA. Sections of the Manual will be revised from time

to time, and it will be the responsibility of all

Consultants using the Manual to ensure that they

are working to the current issue. The DA can be

contacted for information on revisions. Any errors or

omissions, or recommendations should be notified

to the Designs Department DA.

Original drafts were produced using Microsoft Word,

and converted to Adobe Acrobat files for use by the

DA. Paper copies will be distributed to consultants

on request.

A web version of the Manual will also be developed

by the DA following initial launch.

Copyright of the Manual in its current format is the

property of the DA and it may not be reproduced in

any format without written permission of the DA.

Use of the Manual does not absolve design

consultants from their normal responsibilities. The

Manual is be utilised as a guide to good practice and

should be used only by competent practitioners, with

due diligence.

1.1 Terms of Reference

This Manual was written by Hyder Consulting Middle

East Ltd (HCME). under the terms of the DA PSA

DFC1050/D9. The content of the Manual was

developed from Appendices A and B of the PSA

(developed during the period 1997–2000 by staff of

the DA). The initial PSA was issued for competitive

tenders in 2000, and Hyder was commissioned to

prepare the Manual in 2003.

1.2 Manual Development Process

The initial PSA contents were further developed

during 2003 through a series of meetings between

Hyder specialists and DA staff. Information obtained

during these meetings included DA policy on

drainage planning, operational policies, preferences

for equipment, procurement strategies, and practical

issues associated with the operation of the existing

infrastructure.

Visits were made to Consultants ASCO and KAME

site offices to view typical local construction

conditions including; high water tables, deep

excavations and micro-tunnelling.

1.3 Recommendations for Additional Study

The Manual will serve as a useful guide for

experienced designers in design for the DA. It is not

exhaustive in its’ coverage, and is not intended to

replace the standard texts or proven theory listed

elsewhere.

Where detailed procedures are considered to be

beyond the scope of the Manual, some

recommendations are made for further reading. For

example, the Trenchless Section within Volume 2,

includes discussion of design of jacking pipes, thrust

and delivery pits for new installations. These

activities are always carried out by experienced

specialist contractors, however, design consultants

may wish to check the adequacy of these designs.

Hence references are provided for this purpose.

With trenchless installation for rehabilitation of

existing sewers, there is a wealth of literature

commonly cited for reference.


Page 2 Volume 1 General


As current DA preference in Qatar is for new-build,

the rehabilitation of existing sewers is covered by

cross-references to some of the more commonly

used literature.

1.4 Manual Updating

Updates to the Manual will be issued periodically.

These will incorporate any technical improvements

identified since the last revision, in addition to any

new or updated references/publications included in

the Manual. Descriptions of the updates will be

forwarded to all consultants, whilst both hard and

digital copies will be available on request from the

DA.

1.5 Literature/References

The following list of references has been compiled

from Volumes 1 to 8 of the Manual. References

used within this volume are also included at the end

of the text.

• B Maidl, M. Herrenknecht, L.Anheuser,

Mechanised Shield Tunnelling, Ernst & Sohn

Publications.

• Bazaraa, A.S., Ahmed, S., 1991. Rainfall

Characterization in an Arid Area, Engineering

Journal of Qatar University, Vol. 4, pp35-50.

• Bowker D. G., Smith J. M., and Webster N. A.,

1989, Odour and Corrosion Control in Sanitary

Sewerage Systems and Treatment Plants,

United States, Hemisphere Publishing

Corporation.

• British Standards Institution, 1997, BS 8301:

Code of practice for building drainage, London,

BSI. ISBN 0-89116-067-1.

• Bras, R.L., 1990, Hydrology: An Introduction to

Hydrologic Science, Addison-Wesley.

• Building Research Establishment, Digest 250:

Concrete in sulphate-bearing soils and ground

water. UK, BRE.

• British Standards Institution, 1989, BS 8010-

1:1989 - Code of practice for Pipelines, Part 1:

Pipelines on land: general, London BSI.


2:1997 - Noise and vibration control on

construction and open sites — Part 2: Guide to

noise and vibration control legislation for

construction and demolition including road

construction and maintenance. London, BSI.


1:1981 Precast concrete pipes and fittings for

drainage and sewerage. Specification for pipes

and fittings with flexible joints and manholes

(No longer current but cited in the Building

Regulations), London, BSI.

• British Standards Institution, 1992, BS

6472:1992: Evaluation of human exposure to

vibration in buildings (1Hz to 80Hz), London,

BSI.

• British Standards Institution, 1990, BS 7385 -

1:1990, Evaluation and measurement for

vibration in buildings. Guide for measurement

of vibrations and evaluation of their effects on

buildings, London, BSI.

• British Standards Institution, 1990, BS 7385 -

1:1990, Evaluation and measurement for

vibration in buildings. Guide for measurement

of vibrations and evaluation of their effects on

buildings, London, BSI.

• British Standards Institution, 1990, BS1377:

1990 - Methods of test for soils for civil

engineering purposes. London, BSI.


1981- Code of practice for site investigation,

London, BSI.


2001 - Code of practice for safety in tunnelling

in the construction industry, London, BSI.


1991: Guide to selection and application of flow

meters for the measurement of fluid flow in

closed conduits. London, BSI.

• British Standards Institution, 1991, BS EN ISO

6817: 1997: Measurement of conductive liquid

flow in closed conduits. London, BSI.

• Chow, V.T., Maidment, D.R., Mays, L.W., 1988.

Applied Hydrology, McGraw-Hill, p140.




• Construction Industry Research and

Information Association, 1997, Special

Publication 137: Site Safety for the Water

Industry, London, CIRIA.

• E.J. Cording, T.D. O’Rourke, and

M.D.Boscardin, 1978, Ground Movements and

Damage to Structures, Proc., Int. Conf. On

Evaluation and Prediction of Subsidence,

Florida, pp 516-537.

• Foundation for Water Research, 1993,

Enclosed wastewater treatment plants - health

and safety considerations, FR/W 0001, UK,

FRW.

• British Standards Institution, 1998, BS EN

1508:1998, Water supply - Requirements for

systems and components for the storage of

water, London, BSI.

• British Standards Institution, 2000, BS EN

805:2000, Water supply - Requirements for

systems and components outside buildings,

London, BSI.

• United Nations, 1985 , Food & Agriculture

Organisation of the United Nations, Rome, UN.

• Milligan G., Norris, P., , Pipe jacking: Research

results and recommendations, Pipe Jacking

Association.

• International Society for Trenchless

Technology, 1992, Introduction to trenchless

technology, 2nd edition, ISTT.

• Tyson A., and Harrison K, Irrigation for Lawns

and Gardens, Extension Agricultural Engineers,

The University of Georgia College of

Agricultural & Environmental Sciences.

• Burland J.B., and Wroth C.P, 1975, Settlement

of Buildings and Associated Damage, Building

Research Establishment Current Paper,

Watford, Building Research Establishment.

• Burland J.B., 1997, Assessment of risk of

damage to buildings due to tunnelling and

excavation, Earthquake Geotechnical

Engineering, Ishihara (ed.), Balkema,

Rotterdam, pp. 1189-1201.

• Boon, A.G., 1992, Septicity in sewers: Causes,

Consequences and Containment. JIWEM, Vol

6 No.1, February 1992, pp.79-90.

• Linsley, R.K., Kohler M.A. & Paulhaus, J.L.H.,

1982, Hydrology for Engineers, 3rd Edition,

McGraw-Hill.

• Ministry of Civil Aviation and Meteorology,

State of Qatar, 2002. Long Term Climate

Report –2000, extracted from Long Period

Means & Extremes of Climatological Elements,

Doha International Airport, period (1962-2002),

Qatar Ministry of Civil Aviation and

Meteorology.

• Morin, J., and Benyamini, Y., 1997. Rainfall

Infiltration into Bare Soils, Water Resources

Research, 13(5), pp812-817.

• Water Research Centre, Network analysis - A

code of practice, UK, Water Research Centre.

• Peck, R. B., 1969, Deep excavations and

tunnelling in soft ground. Proc. of 7th Int. Conf.

Soil Mech., Mexico, State of the Art 3, pp. 225-

290.

• Pipe Jacking Association, 1987, A guide to pipe

jacking and microtunnelling design, Pipe

Jacking Association.

• Water Research Centre, 1995, Pipe materials

selection manual - water supply, 2nd edition,

UK, Water Research Centre.

• US Environmental Protection Agency, 1974,

US EPA Report 625/1-74-005 - Process Design

Manual for Sulphide Control in Sanitary

Sewerage Systems, USA, EPA.

• Ministry of Municipal Affairs and Agriculture,

1997, Qatar Highway Design Manual, January

1997, Qatar, MMAA.

• Taylor, R. N., and Bracegirdle, A., 1993,

Subsurface settlement profiles above tunnels in

clay, Geotechnique, 43(2), pp.315-320.

• Reynolds, C.E. and Steedman, J.C, 1988,

Reinforced Concrete Designers Handbook. 10th

ed. London, Spon Press.




• Boone S.J., 1996, Ground Movement Related

Building Damage, Journal of Geotechnical

Engineering, ASCE, 122(11), pp. 886-896.

• State of Kuwait Ministry of Planning & Hyder

Consulting, 2001, Kuwait Stormwater

Masterplan Hydrological Aspects - Final

Report. Cardiff, (AU00109/D1/015), Hyder

Consulting.

• State of Qatar, 2002, Law No. 30:

Environmental Protection, Qatar, State of

Qatar.

• HR Wallingford and DIH Barr, 2000, Tables for

the Hydraulic Design of Pipes, Sewers and

Channels, 7th Edition, Trowbridge, Wiltshire,

UK Redwood Books.

• Construction Industry Research and

Information Association, 1994, Guide to the

Design of thrust blocks for buried pressure

pipelines, Report 128, London CIRIA.

• UK Health and Safety Executive, 2002,

Occupational Exposure Limits, EH40/2002, UK,

Health and Safety Executive.

• Various publications arising from time to time

From the Regional Centre for Environmental

Health Activities (CEHA), a subgroup of WHO,

dealing specifically with issues relating to the

Eastern Mediterranean Countries, having a

similar climate to the Gulf Region. They

publish notes of their programmes on the

internet.

• Vincent A.J., 2001, Sources of odours in

wastewater treatment, eds. Stuetz R. and

Frechen F.B., Odours in Wastewater

Treatment, IWA Publishing.

• Twort, A.C., Ratnayaka, D.D., Brandt, M.J.,

2000,Water Supply, 5th Edition, Arnold and

IWA Publishing.

• Washington State Department of Health, 2001,

Water System Design Manual, Washington,

State Department of Health.

• Blumenthal et al, 2000, Guidelines for the

Microbiological Quality of Treated Wastewater

Used in Agriculture: Recommendations for

Revising WHO Guidelines, World Health

Organisation.

• World Health Organisation, 2000, WHO EHC

216 Environmental Health Criteria –

Disinfectants and Disinfectant By products,

World Health Organisation.

• World Health Organisation, WHO Guidelines

for the Safe Use of Wastewater and Excreta in

Agriculture and Aquaculture, World Health

Organisation.

• World Health Organisation, 1987, Air Quality

guidelines for Europe, WHO Regional

Publications Series No. 23, Regional Office for

Europe Copenhagen, World Health

Organisation.

• Building Research Establishment, 1991,

Soakaway Design, BRE Digest 365, BRE

Watford.




2 Planning Issues

2.1 Master Plans

Master Plans set the policy for each particular

service and will be carried out on a regional scale to

suit the specific requirements. The three main types

of Master Plans undertaken by the DA are:

• Sewerage;

• Surface and Ground Water Drainage;

• Treated Sewage Effluent/Irrigation. Each Master Plan should incorporate the main three

elements:

• Data Collection and Scoping;

• Capability of Existing Facilities;

• Recommendations for Future Requirements.

Design Consultants should contact the DA for

information regarding Master Plans

2.1.1 Sewerage

Sewage Treatment Works

Sewage treatment works are the focal point of each

sewerage system. Provision of sufficient treatment

capacity is the most important factor in the planning

of a sewerage network. Disposal of the arisings,

sludge, and TSE, also have to be planned to enable

a balanced system to be constructed.

Existing Assets

Identification of existing and proposed assets is

essential to the development of a Master Plan. This

will include:

• Details of the network: i.e. plots connected;

manhole locations; pipe diameters/materials;

and levels;

• Contributing pumping stations;

• Schemes under design and construction.

Land Use

Fundamental to the planning of the scheme is the

type of land use, as this will set the criteria on which

generated sewerage and surface flow will be

determined. Information in this respect can be

obtained from the Lands Department. Where

information is not available, the consultant should

clearly state on what assumptions the planning has

been undertaken, in terms of land use and

estimated flows to the sewerage system.

Population Estimates

Data on existing and future populations are essential

to the overall planning of an area. The expected

timing of population growth is important so as to set

the programme for the network development and

sewage treatment requirements. Information in this

respect can be obtained from the Planning Council

who undertake the population census in Qatar.

Adequacy of Existing Systems

Implementation of a new Master Plan will result from

a change to the criteria on which the design of

existing works was based. This would either imply a

surplus or deficiency in the existing works. The

consultant must, in the preparation the Master Plan,

ensure that any upgrading or redundancy is carried

out in an economical fashion.

Utilisation of Natural Topography

Having assessed the population in all areas of the

catchment, and thus the predicted flows, the best

route for conveyance to the treatment facilities

needs to be determined. In this determination the

natural ground topography must be used to

minimise the depth of sewers and reduce the

number and size of forwarding pumping stations.

Land Acquisition

During the development of the Master Plan there

may be a need for land to be purchased. In this

event, the consultant is to make the requirements

clear to the DA so the feasibility of purchasing the

land can be determined.

Preparation of Options




The process described above will lead to the

development of several options with differing merits

and demerits, such as reduced sewer depths or

fewer pumping stations. The consultant is to prepare

a detailed study of the different options and make a

recommendation as to which is to be adopted.

2.1.2 Surface and Ground Water

Discharge Points

The identification of existing and potential discharge

points is the first stage in the assessment of any

Surface Water Master Plan. These vary greatly in

capacity and availability and include:

• Sea Outfalls;

• Flooding Areas;

• Existing Facilities;

• New Pumping Stations and Pumping Mains;

• Infiltration system such as chamber and

trench soakaways.

• Storage Tanks

The consultant is to identify and assess the usage of

all available options.

Natural Topography

This is of the utmost importance in preparing a

Master Plan, as it will determine the catchment area

and natural surface water flow routes. A full-scale

topographical survey would not be appropriate at the

Master Planning stage so the consultant must

carefully assess the accuracy of the available data.

It is also noted that future development can change

the surface flow characteristics of surface water due

to land use change or road construction. The

bearing these would have on the flow need to be

identified and incorporated into the Master Plan.

Ground Water Control

Ground water levels can have a significant effect on

the design of surface water systems, as it will affect

the surface absorption and potential for the use of

infiltration systems. Master Plans should therefore

identify any requirements for ground water control

and methods by which this can be achieved.

Existing and Proposed Assets

Identification of existing/proposed assets is essential

to the development of a Master Plan. This will

include:

• Details of networks;

• Type of surface/ground water disposal

employed;

• Pumping stations and rising mains;

• Outfalls available;

• Schemes under design and construction.

• Historical information

Definition of Rainfall Characteristics

These are to be identified and quantified at the

Master Planning stage as they are fundamental to

any design and will be required for the analysis

described below.

Analysis

Computerised modelling is to be undertaken at the

Master Planning stage to assess the overall run-off

and flow characteristics. This will demonstrate the

need for major works such as pumping stations,

attenuation tanks, and main pipeline routes and

sizes. This will be used to develop the various

options for the Master Plan.

Land Use


land use, as this effects the development type, run-

off characteristics, and more importantly, the design

storms applicable to a specific area. Information in

this respect can be obtained from Lands

Department.

Land Acquisition

During the development of the master plan there

may be a need for land to be purchased. In this

event the consultant is to make the requirements

clear to the DA so the feasibility of purchasing the

land can be determined. This is a critical factor in

determining the overall scheme, especially where

flooding areas or large attenuation tanks are

desirable options.







and demerits such as use of attention tanks or large

diameter pipelines. The consultant is to prepare a

detailed study of the different options and make a


2.1.3 Irrigation using TSE

Identification

The identification of existing and proposed assets

will be the first stage in master planning as this will

define the existing supply points and sources.

Existing TSE irrigation assets may include:

• Pumping Stations;

• Elevated Towers;

• Supply and Distribution networks.

Land Use


land use, as this affects the development type and

will effect the irrigation requirements and TSE

demands. Information in this respect can be

obtained from the Lands Department.

Planting Scenarios

The purpose of the irrigating system is to support

plant life, therefore assessing likely plant irrigation

regimes and resultant demand is of the utmost

importance. The consultant is to produce various

planting options and assess the effect on the overall

scheme and TSE supply/demand balance.

Supply Facilities

The next major factor in the development of a

Master Plan is the main supply method, e.g.

pumping stations, or elevated towers. The

consultant is to identify the options, outline the

advantages and disadvantages of each, and the

suitability of the various methods available.

Distribution Networks

Computerised modelling of the distribution system is

to be undertaken to establish the pipeline routes,

diameters and materials. This should demonstrate

that all the necessary hydraulic design parameters

are achieved.

Land Acquisition

As noted in previous sub-sections the consultant is

to ensure that any need to purchase land is made

clear to the DA.




and demerits such as the use of pumping stations or

elevated towers. The consultant is to prepare a

detailed study of the different options and make a


2.2 Allocation of Lands

Land in Qatar has generally been allocated with

certain plots owned by the Government. The DA are

allocated some of these plots for existing and future

works.

When the need for land is identified on a particular

project the following procedure should be followed:

• Check that a plot has already been allotted

to the DA. If this is the case, confirmation

with the DA is required to check that the plot

is available for the specific use intended;

• Check that a Government plot is available.

In this case, a check is required to assess if

the plot has been allocated to a specific

Government authority. If the plot is available

for use, then an application for transfer to

the DA should be made. If a plot has been

allocated to another authority but is

undeveloped then that authority’s

requirement for the plot is to be ascertained,

and potential for transfer to the DA;

• Where no Government plots are available,

an undeveloped plot will need to be

identified. Once this has been done,

permission for the proposed use will need to

be obtained from Lands Department. When

it has been obtained, the matter will be

referred to Lands Acquisition Department for

Government purchase.




2.3 Statutory Undertakers

The process for applying for and monitoring receipt

of information from the statutory authorities is

described in Section 5. These enquires should

highlight the need for any particular requirements for

service co-ordination, or special measures required

for the project.

If the need for such measures becomes apparent,

then the consultant is to undertake all the necessary

co-ordination and design work to ensure the

authority’s requirements are met.

2.4 Infrastructure Projects

The DA usually administers projects that are solely

for their own assets. However, where infrastructure

projects are undertaken, this will bring together the

design aspects of several Departments and

authorities. The Roads Affairs usually administers

these types of projects. However it is imperative that

the design of any DA works is undertaken with its

full knowledge and approval.

2.5 Catchments & Flood Plains

Catchments, subcatchments and floodplain areas

have been identified in most areas by the DA.

Designers must check these against current

developments.

Where such master plans identify areas that need to

be reserved, i.e. not developed, then the land

acquisition measures described in Section 2.2

above need to be followed.

2.6 Groundwater

Groundwater control is a key aspect of drainage

design because:

• Parts of Doha City experience severe

drainage problems associated with high and

rising groundwater levels and low

permeability rates (i.e. perched water

tables);

• The ability of soakaways to function is

critically dependent on the local

hydrogeological conditions.

Variations in geological, hydrogeological and

topographic conditions, together with the extent of

urban development, are the main influences on

groundwater conditions. The geological conditions

control hydrogeological properties, especially the

ability of the ground to accept, store and transmit

groundwater. Topography is an issue because of the

shallowness of the water table in low-lying areas.

New development is particularly important because

it is almost always associated with enhanced

recharge to groundwater, due to the installation of

soakaways, septic tanks, excess irrigation etc. and

this results in a rise in water table levels.

These issues have significant practical implications

that designers of drainage systems must recognise.

For example, the ability of soakaway systems to

function properly depends on the permeability and

effective porosity of the soil medium. In some cases

the ground is effectively impermeable and standard

chamber-type soakaways will simply not function.

Similarly, groundwater levels may rise to the extent

that there is no significant head difference between

the water level in the soakaway after a storm and

the pre-storm groundwater level outside it. Under

such circumstances the soakaway will not function

effectively.

Numerous studies, reports and internal documents

have addressed the groundwater issue and the

adverse consequences of high and rising

groundwater levels are well documented. The

principal adverse effects are reported as:

• Unsightly, unhygienic and disruptive

accumulation of water at the surface;

• Damage to infrastructure such as telephone

and power cables;

• Damage to the fabric of buildings;

• Leakage to basements in old properties;

• Possible geotechnical instability.

It is generally regarded that groundwater levels

should be no higher than four metres (4m) below

ground level. In practice, three metres is a safe

level but using four metres builds in a factor of

safety allowance to cater for temporary rises due to




rainstorms and the more extreme effects of urban

development. Four metres is taken as being a target

level that can safely be adhered to.

In strategic planning terms it should be noted that

several different government departments have a

direct interest in groundwater. These include: the DA

for reasons explained above; the Roads Affairs

because of its use of soakaways for roads drainage;

the Agriculture Department because of its use of

groundwater for irrigation; and the Ministry of

Electricity and Water which is understood to

maintain a network of groundwater monitoring

boreholes in Doha City. The Roads Affairs is

particularly important because of the opportunity

some of its works present to help deal with the

groundwater drainage problem. The private sector

also has an interest because of the need to consider

groundwater levels and drainage requirements in

building design.

It may be noted that these different interests cause

the organisations involved to focus on different parts

of the hydrogeological system and this is reflected in

the publications produced. The Department of

Agriculture is concerned with water resources and

will tend to concentrate on the deeper groundwater

in the freshwater lens, typically more than 50m

below ground level (i.e. down to the Rus / Umm er

Rhaduma interface). By contrast, the DA needs a

detailed understanding of the conditions that

characterise the 0-15m depth range (i.e. above

Midra shale), particularly the 0-10m section. Also,

whereas the other departments are concerned with

groundwater per se., the Roads Affairs is concerned

primarily with ground strength.

In general terms, what results from the above

discussion, is as follows:

• There is a need to understand the

hydrogeological conditions that characterise

an area as a basis for designing schemes

guaranteed to maintain acceptably low

groundwater levels;

• There is a need to maintain liaison between

government departments in respect of

groundwater drainage, including free

exchange of information where possible.

Meeting these needs is the objective that underpins

the references to groundwater that are contained

within the Design Manual.

It is recognised that this manual is expected to be a

guide to drainage requirements in the whole of the

State of Qatar. However most attention will be given

to the greater Doha area because of the rapid

development compared to the rest of the country. It

is inevitable that the level of understanding of the

critical hydrogeological conditions that characterise

the shallower geological formations is better for the

greater Doha area than for elsewhere, as reflected

in this part of the Manual.

It is intended that the techniques used to acquire

this level of hydrogeological understanding in

greater Doha, may be applied to ensure appropriate

drainage design wherever it is needed in Qatar. It

may be noted in this regard that as long ago as

1983, preliminary studies were carried out that took

into account the hydrogeological conditions relevant

to drainage in the Umm Said, Al Wakrah and Wukair

areas south of Doha.

2.7 Environmental Planning

2.7.1 Introduction

This Section introduces a general overview of the

importance of environmental issues as part of the

planning process for sewerage and drainage

infrastructure projects in Qatar. Further guidance on

environmental impact assessment (EIA) is also

included in: specific sections on Investigations

(Volume 1, Section 3.7); EIA and the design process

(Volume 1, Section 4.7); surface water and ground

water control (Volume 3, Section 3.2); treated

sewage effluent (Volume 4, Section 1.5); and

sewage treatment plant design and odour (Volume

5, Section 1.5).

Increasing environmental awareness and global

concerns over sustainability have broadened the

range of issues that need to be examined in the

assessment of the potential impacts of proposed

projects and programmes. Three different concepts

of sustainable development may be identified.

These are based on economic, ecological and

socio-cultural criteria.




The economic approach to sustainability is based on

the concept of maximising the flow of income that

could be generated through maintaining assets

and/or capital. The ecological view of sustainable

development focuses on the stability of biological

and physical systems and overall ecosystems.

Protection of biological diversity is a key component

of the approach. The socio-cultural concept of

sustainability seeks to maintain the stability of social

and cultural systems. These concepts should be

considered during the impact assessment process.

he identification of sustainable development options

requires:

• A good understanding of the physical,

biological and social impacts of human

activities;

• Good estimates of the real economic value

of investment proposals.

General sustainability objectives for various

environmental parameters are identified in Table

2.7.1 below.

Sustainable development is achieved most

efficiently when negative and positive environmental

impacts are identified and addressed at the earliest

possible project planning stage.

The environmental sections within this manual

provide practical guidance for designing sustainable

sewerage and drainage projects in Qatar. The aim

is to provide specific information and guidance as

common ground for discussion among those

involved – designers, operators, EIA professionals,

planners, regulators and the Government in general.




Table 2.7.1 - General Sustainability Objectives

Parameter Objective

Community Cohesion and Social Equity To provide benefits for local communities and minimise disruption from development and training activities

Land Use

To help provide a good quality of life for all who live and work on the estate, take full account of environmental considerations, and encourage public access within operational, safety and conservation constraints

Biodiversity and Nature Conservation To reverse trends of damage to biodiversity, in the sea and on land, and identify enhancement opportunities

Landscape and Townscape To reverse trends of damage to landscape character and identify enhancement opportunities

Archaeology & Cultural Heritage To protect and enhance all aspects of the historic, archaeological and cultural environment for their own sake, and as a central part of our cultural heritage

Climate Change & Air Quality To achieve major long term cuts in greenhouse gas emissions and improve the quality of air

Water and Drainage To safeguard marine resources, reduce the threat of pollution, and prevent death, property damage, and distress from flooding

Traffic and Transport To reduce the need to travel, especially by road and air, and increase the use 0f coastal shipping

Geology and Soils

To protect soil as a limited resource, remove unacceptable risks to human health and the environment from contamination, and seek to bring damaged land back into beneficial use

Energy Consumption and Supply To ensure the prolonged availability of finite fossil fuels, improve energy efficiency and support the development and use of renewable energy sources such as solar power

Waste Management To move away from the disposal of waste towards reduction, recycling and recovery

Efficient Use of Land, Buildings and Construction Materials

To maximize the efficient use of land and construction materials, and pursue opportunities for sustainable building design

Economic Prosperity To maintain and encourage a diverse and thriving economy




2.7.2 Planning

Decisions on the type and location of sewerage and

drainage infrastructure are crucial and should not be

made without adequate information (see also

Section 2.1). Full consultation must be made with

the DA in all stages of the planning process.

The level of sewage treatment depends on the

performance standards that apply to the system

(see also Volume 1, Section 4.7). These are usually

expressed as limitations on the concentration of

regulated substances permitted in the treated

effluent. In cases where Treated Sewage Effluent

(TSE) is applied to crops or otherwise used on land

(as is often the case in arid states such as Qatar),

the standards are set to prevent crop and

groundwater contamination.

A second component of planning involves the

sequencing and phasing of projects as part of long-

term pollution abatement programmes, and in

relation to activities in other sectors. In addition to

the aspiration for sustainable development, there

are specific environmental laws in Qatar that require

compliance.

The SCENR are the Licensing Authority and must

be involved as statutory consultees. EIA Procedures

have been developed by SCENR. These relate to

the legal requirement of the State of Qatar for

polluting industries to conduct an EIA (Law No. 30,

2002), the policy of the State, and its commitment to

the outcomes of the United Nations Conference on

Environment and Development, 1992.

Law 30 dictates that EIAs be undertaken for specific

projects, including ‘waste disposal or treatment

facilities, including hazardous waste treatment’, and

‘projects which may effect ground water including

irrigation and drainage projects’. As a result,

sewerage and drainage projects require submission

of an ‘Application form for Initial Environmental

Authorisation’ to the SCENR. Prior to the

submission of this form it is good practice to consult

with SCENR and the Planning Department to

discuss the scale of the proposed project and its

location. This will enable confirmation that the

proposed works location falls in an approved zone

on the basis of land use planning, and whether or

not an EIA is required.

2.7.3 Screening

In the strategic planning context, given the

importance of the environment on planning

development, it is good practice to consult with

SCENR and the Planning Department prior to

project conception. This enables key areas to be

identified that might inhibit a project developing

further in the future, for example, the proposed

works may be located in:

• an ‘Environmental Protection Area’;

• land use zone inappropriate for sewerage or

drainage works; or

• dense human population areas.

Screening out potentially sensitive projects with

unacceptable environmental impacts, or with no

agreement on ‘environmental clearance’ ensures

optimised, efficient and effective use of resources. A

useful tool which can be used during the screening

process is the environmental matrix, giving a simple

visual representation of potential hold points during

the anticipated stages of a project. An example is

shown in Table 2.7.2.




Table 2.7.2 - Environmental Screening Matrix Planning

Design

Construction

Operation

Decom

missioning

Social ○ ○ Land Amenity ● ● ● ○ ○ Public Health ● ● ● ○ Economic Visual ○ Marine ● ● ○

Air pollution ● ○ Noise ● ● ●

Ecological ● ●

Archaeological ●

○ Denotes positive impact

• Denotes negative impact

Location of Projects

The environmental sensitivity of geographical areas

likely to be affected by projects must be considered,

in particular, having regard to:

• the existing land use;

• the relative abundance, quality and

regenerative capacity of natural resources in

the area;

• the absorption capacity of the natural

environment, paying particular attention to

the following areas:

1) coastal zones;

2) nature reserves and parks;

3) areas classified or protected under

Qatari legislation;

4) landscapes of historical, cultural or

archaeological significance.

Characteristics of Projects

The following must be considered:

• the size of the project;

• the cumulative effect with other projects;

• the use of natural resources;

• the production of waste;

• pollution and nuisances;

• the risk of accidents, having regard in

particular to substances or technologies

used.

Characteristics of the Potential Impact

The following must be considered:

• the geographical extent of the impact;

• probability;

• duration, frequency and reversibility.

Assuming that an EIA is required for a particular

sewerage or drainage project, then the EIA

Procedures (available from SCENR) should be

closely followed, with frequent consultation with

SCENR.

It should be noted that it is often the case that an

EIA is prepared prior to, or during preparation of the

Initial Environmental Authorisation (IEA) process.

This is because EIA is often undertaken during the

preliminary design process, with environmental

mitigation being built into the final designs (see

Volume 1, Section 4.7). Early consultation with

SCENR may have identified a clear need for an EIA,

and as such, the EIA can then be submitted with the

IEA application at a later date, as at this stage more

detailed design information may be available.




2.7.4 Scoping

It is a requirement of Law 30, to undertake an EIA

Scoping Study prior to undertaking a full EIA. This

stimulates early consultation with SCENR, and

others. The Scoping Study should consider the

following sections:

Project description:

• a description of the physical characteristics

of the project and land-use requirements

during the project lifetime;

• a description of the main characteristics of

any production processes, for instance,

nature and quantity of the material used;

• an estimate, by type and quantity, of any

expected residues and emissions (water, air

and soil pollution, noise, vibration, light, heat,

radiation, etc).

An outline of the main alternatives studied by the

developer, and an indication of the main reasons for

the proposed alternative, taking into account the

environmental effects.

A description of the receiving environment,

population, fauna, flora, soil, water, air, climatic

factors, material assets, architectural and

archaeological heritage, landscape and the inter-

relationship between the above factors.

A description of the environmental impact which

should cover the direct effects and any indirect,

secondary, cumulative, short, medium and long-

term, permanent and temporary, positive and

negative effects of the project), resulting from:

• the existence of the project;

• the use of natural resources;

• the emission of pollutants, the creation of

nuisances and the elimination of waste;

• the description by the developer of the

forecasting methods used to assess the

effects on the environment.

Proposed mitigation steps.

A non-technical summary.

An indication of any difficulties encountered in

compiling the required information.

The ‘Scoping’ approach encourages efficient and

effective use of resources, by focusing any required

EIA on the important issues only.

2.7.5 EIA

An EIA may be required by the DA for larger

projects. This will be indicated in the PSA.

It is good practice to submit a Draft EIA to SCENR

prior to IEA application. This approach should be

incorporated into the project programme.

On finalisation, the EIA should be submitted with the

IEA Application. A ‘clearance’ decision should be

reached by SCENR within 30 days. A key

component of the decision is the EIA report and its

contents. The EIA should include (following similar

lines to 2.7.4 above, but in greater detail) the

following sections indicated as follows:

Information Describing the Project

• Purpose and physical characteristics of the

project, including details of proposed access

and transport arrangements, and of numbers

to be employed and where they will come

from;

• Land use requirements and other physical

features of the project:

1) during construction;

2) when operational;

3) after use has ceased (where

appropriate).

• Production processes and operational

features of the project:

1) type and quantities of raw materials,

energy and other resources

consumed;

2) residues and emissions by type,

quantity, composition and strength

including:

i) discharges to water;

ii) emissions to air;

iii) noise;

iv) vibration;




v) light;

vi) heat;

vii) radiation;

viii) deposits/residues to land

and soil;

ix) others.

3) Main alternative sites and processes

considered, where appropriate, and

reasons for final choice.

Information Describing the Site and its

Environment

• Physical features;

• Population - proximity and numbers;

• Flora and fauna (including both habitats and

species) - in particular, protected species

and their habitats;

• Soil - agricultural quality, geology and

geomorphology;

• Water - aquifers, wadis, shoreline, including

the type, quantity, composition and strength

of any existing discharges;

• Air - climatic factors, air quality, etc.;

• Architectural and historic heritage,

archaeological sites and features, and other

material assets;

• Landscape and topography;

• Recreational uses;

• Any other relevant environmental features.

The Policy Framework

Where applicable, the information considered under

this section should include all relevant statutory

designations. These may include nature reserves

and any area allocated for the preservation of a

species of plants, animals, birds or aquatic life in

danger of becoming extinct, in which it is prohibited

to eliminate, hunt or kill such species, and which

shall be determined by a decision of SCENR.

Consideration should additionally be given to areas

and sites of environmental importance as defined by

the Qatari Environmental Protection Standards

(2003).

This should also include references to relevant

national policies and to regional and local plans and

policies (including approved or emerging

development plans).

Reference should also be made to international

designations, for example. those defined under the

Biodiversity Convention and the Ramsar

Convention.

Assessment of Effects

This includes direct and indirect, secondary,

cumulative, short, medium and long-term,

permanent and temporary, positive and negative

effects of the project. The following effects should be

considered:

Effects on human beings, buildings and man-

made features:

• Change in population arising from the

development;

• Visual effects;

• Levels and effects of emissions during

normal operation;

• Levels and effects of noise.

Effects of the development on local roads and

transport.

Effects of the development on buildings, the

architectural and historic heritage,

archaeological features, and other human

artifacts, e.g. through pollutants, visual intrusion,

vibration.

Effects on flora, fauna and geology:

• Loss of, and damage to, habitats and plant

and animal species;

• Loss of, and damage to, geological,

palaeontological and physiographic features;

• Other ecological consequences.

Effects on land

• Physical effects of the development, e.g.

change in local topography, effect of earth-

moving on stability, soil erosion, etc.;

• Effects of chemical emissions and deposits

on soil of site and surrounding land;




• Land use/resource effects:

1) quality and quantity of agricultural

land to be taken;

2) sterilisation of mineral resources;

3) other alternative uses of the site,

including the `do nothing' option;

4) effect on surrounding land uses

including agriculture;

5) waste disposal.

Effects on water

• Effects of development on drainage pattern

in the area;

• Changes to other hydrographic

characteristics, e.g. groundwater level, water

courses, flow of underground water;

• Effects on coastal or estuarine hydrology;

• Effects of pollutants, waste, etc. on water

quality.

Effects on air and atmosphere

• Level and concentration of chemical

emissions and their environmental effects;

• Particulate matter;

• Offensive odours;

• Any other climatic effects.

Other Indirect and Secondary Effects Associated

with the Project

• Effects from traffic (road, rail, air, water)

related to the development;

• Effects arising from the extraction and

consumption of materials, water, energy or

other resources by the development;

• Effects of other development associated with

the project, e.g. new roads, sewers, housing,

power lines, pipe-lines, telecommunications,

etc.;

• Effects of association of the development

with other existing or proposed development;

• Secondary effects resulting from the

interaction of separate direct effects listed

above.

Mitigating Measures

Where significant adverse effects are identified, a

description of the measures to be taken to avoid,

reduce or remedy those effects, for example:

• site planning;

• technical measures, including:

1) process selection;

2) recycling;

3) pollution control and treatment;

4) containment (e.g. bunding of storage

vessels).

• aesthetic and ecological measures, e.g.:

1) mounding;

2) design, colour, etc;

3) landscaping;

4) tree planting;

5) measures to preserve particular

habitats or create alternative

habitats;

6) recording of archaeological sites;

7) measures to safeguard historic

buildings or sites.

• Assessment of the likely effectiveness of

mitigating measures.

Risk of Accidents and Hazardous Development

Risk of accidents as such is not covered in the

Qatari Environmental Protection Law or,

consequently, in the implementing Rule on EIA.

However, when the proposed development involves

materials that could be harmful to the environment

(including people) in the event of an accident, the

environmental statement should include an

indication of the preventive measures that will be

adopted so that such an occurrence is not likely to

have a significant effect. This could, where

appropriate, include reference to compliance with

Health and Safety legislation.

There are separate arrangements in force relating to

the keeping or use of hazardous substances and the

Health and Safety agency provides local planning

authorities with expert advice about risk assessment




on any planning application involving a hazardous

installation.

Nevertheless, it is desirable that, wherever possible,

the risk of accidents and the general environmental

effects of developments should be considered

together, and developers and planning authorities

should bear this in mind.

2.7.6 Conclusions

Any approval might be accompanied by specific

conditions, normally related to capacity and

processes specified (if these change, then re-

application is required), mitigation and/or monitoring

measures, which are identified in the EIA. Prior to

operation of new works a ‘Permit to Operate’ is

required from SCENR. This is the mechanism by

which SCENR can check that the IEA Approval

Clearance conditions (if any) have been actioned.

The environment has a significant impact on the

planning process for sewerage and drainage

projects. Consultation with SCENR and the Planning

Department, environmental impact screening,

scoping and detailed assessment are often key

components of securing regulated clearance to

proceed with a project proposal. Strict adherence to

the EIA Procedure is required.

Detailed examples of International Best Practice for

EIA as part of the project cycle for sewerage and

drainage projects are as follows:

• UK Environment Agency Scoping Guidelines

for EIAs, May 2002;

• UK Office of the Deputy Prime Minister EIA

Guidance on Procedures;

• World Bank Environmental Assessment

Sourcebook Volume 1 Policies, Procedures,

and Cross Sectoral Issues, 1992;

• World Bank Environmental Assessment

Sourcebook Volume 2 Sectoral Guidelines

Wastewater Collection, Treatment, Reuse,

and Disposal Systems, 1992;

• Asian Development Bank Environmental

Guidelines for Selected Infrastructure;

More detailed information regarding the

investigations and content required for sewerage

and drainage project scoping studies and EIA’s are

included in Volume 1, Section 3.7, and Section 4.7,

Volume 3, Section 3.2, and Volume 4, Section 1.5.

EIA as part of the planning process assists in

making good decisions, to screen strategies and

projects efficiently for their environmental impacts, to

clarify to Governments what is needed for

sustainable projects, and to design them effectively.




3 Investigations

3.1 Geotechnical

3.1.1 Introduction

This section of the Design Manual provides general

guidance on the investigation of sites in Qatar for

the purposes of assessing their suitability for the

construction of sewerage and drainage works. It

also covers the acquisition of knowledge on the

characteristics of a site that affect the design and

construction of such works, and the security of

adjacent land and properties. Guidance on the

selection of construction sites with regard to the

wider environmental and economic considerations

affecting the community is outside the scope of the

Geotechnical Section of the Design Manual.

This Design Manual describes design

considerations for site investigations and all involve

some risk to safety unless an appropriate safety

plan has been prepared and implemented. It is

emphasised that safety is of paramount importance

for every activity in site investigation.

An understanding of the geology is fundamental to

the planning of Geotechnical investigations. The

general topography and regional geology in Qatar

are described in Section 4.2 of this Volume.

3.1.2 Investigation Objectives

Investigation of the site is essential to the

construction of sewerage and drainage works. The

purpose and objectives of the investigation are as

follows.

Purpose

The purpose of the investigation is to examine the

general soil conditions at a construction project site,

which will impact any proposed features of a project.

Identifying problem soil conditions prior to schematic

development will enable the designers to produce

the most efficient and cost effective design. Problem

soil conditions may even dictate a different project

alignment than that initially proposed.

Objectives

The investigation should accomplish the following

objectives:

• Assess existing soil data;

• Identify soil and groundwater conditions at

the site;

• Delineate any areas of exceptionally soft

soils;

• Identify any soil instabilities such as slope

failures or geologic faults. In Qatar, natural

soil/rock instability is generally not a cause

for concern due to the landscape topography

of the region. However, this is particularly

relevant to the design of deep cuttings for

underground structures where excavations

may expose soil and rock faces that may

lead to instability;

• Identify long term instabilities such as

uncontrolled earthworks.

The ground is naturally variable and often the nature

of these variations is not known in advance. A site

investigation is a process of continuous exploration

and interpretation, with the scope of the

investigation requiring regular amendment in the

light of the data being obtained. In order to evaluate

properly the nature of the ground and the

groundwater and so to achieve the objectives of the

site investigation, it is essential that the work be

planned, undertaken and supervised by personnel

who have appropriate qualifications, skills and

experience in geotechnical work. If this is not done,

the results and conclusions of an investigation may

be inadequate or even misleading and result in a

considerable over-run of time and expenditure when

the proposed works are under construction.

The extent of the investigation depends primarily

upon the magnitude and nature of the proposed

works and the nature of the site. The former use of a

site and the presence of contamination of the

ground or groundwater can also have a significant

impact on the extent of the investigation.

A site investigation should proceed in stages as

follows:

Stage 1 Desk study and site reconnaissance.




Stage 2 Detailed ground investigation for

design including ground

investigation, topographic,

hydrographic surveying and any

special studies plus interpretative

reports.

Stage 3 Construction review, including any

follow-up investigations during

construction, and the appraisal of

performances.

3.1.3 Desk Study and Site Reconnaissance

The purpose of the desk study is to examine all

information in the project files and literature, which

might yield useful information for the project. The

desk study should cover

Published Literature

Typical soils information sources are:

• Geological maps;

• Geological memoirs;

• Flooding, erosion, landslide and subsidence

history;

• Data held by central and local authorities;

• Construction and investigation records of

adjacent sites;

• Seismicity.

General Land Survey

Typical existing data, which is normally available,

includes:

• Location of site on published maps and

charts;

• Aerial photographs, all dated where

appropriate;

• Site boundaries, outlines of structures and

building lines;

• Ground contours and natural drainage

features;

• Obstructions to sight lines and aircraft

movement, for example transmission lines;

• Indication of obstructions below ground;

• Record of differences and omissions in

relation to published maps;

• Position of survey stations and benchmarks

(the latter with reduced levels);

• Meteorological information.

Site Reconnaissance

At an early stage, a thorough visual examination

should be made of the site to evaluate such

conditions as:

• EFA’s and / or other low lying areas with

perched water tables which may need

special consideration;

• Soft soils indicated by wet areas or

characteristic wet land vegetation;

• Unstable slopes or stream banks;.

3.1.4 Ground Investigation

Consultants should note that the work of all staff and

contractors involved in ground investigation (GI)

would be subject to DA approval.

The objectives of ground investigations are to obtain

reliable information to produce an economic and

safe design, to assess any hazards (physical or

chemical) associated with the ground, and to meet

tender and construction requirements. The

investigation should be designed to verify and

expand information previously collected.

Of primary importance is the establishment of the

soil profile or soil and rock profile, and the

groundwater condition. The profile should be

obtained by close visual inspection and systematic

description of the ground, and by correlation of the

engineering properties of the soils and rocks in

detail. Where appropriate the geometry and nature

of discontinuities should be established.

The investigation should cover all ground in which

significant temporary or permanent changes may

occur as a result of the works. These changes

include: changes in stress and associated strain;

changes in moisture content and associated volume

changes; changes in groundwater level and flow

pattern; and changes in properties of the ground,




such as strength and compressibility. Materials

placed in the ground may deteriorate, especially in

landfill and contaminated former industrial sites. It is

therefore necessary to provide information from

which an estimate of the corrosivity of the ground

can be made.

On many occasions, , a preliminary investigation is

necessary in order that the main investigation may

be planned to best advantage. The main

investigation obtains the bulk of the information

required, but it may be necessary to carry out

supplementary investigations after the main work to

gather more detailed information related to specific

matters.

The ground investigation should be completed

before the works are finally designed. It is therefore

important that sufficient time for ground

investigation, including reporting and interpretation,

is allowed in the overall programme for any scheme.

Should changes in the project occur after completion

of the main investigation, additional ground

investigation may be required.

Sometimes conditions necessitate additional

investigation after the works commence. In

tunnelling, for example, probing ahead of the face

may be required to give warning of hazards or

changes in ground conditions. The properties of the

ground and also the groundwater levels may vary

with the seasons. In planning the investigation,

consideration should be given to predicting the

ground conditions at other times of the year.

The imposition (for reasons of cost and time) of

limitations on the amount of ground investigation to

be undertaken may result in insufficient information

being obtained to enable the works to be designed,

tendered for and constructed adequately,

economically, and on time. Additional investigations

carried out at a later stage may prove more costly

and result in delays.

It is essential that there be adequate direction and

supervision of the work by a competent person who

has appropriate knowledge, training and experience

and the authority to decide on variations to the

ground investigation when required.

Investigations for new works are required to yield

information to assist in selecting the most suitable

location for the works. For instance, when an

excavation has to be carried out, knowledge of the

subsurface strata and groundwater conditions

should indicate, for example:

• whether removal of the material is difficult;

• whether the side of the excavation is stable

if unsupported or requires support;

• whether groundwater conditions necessitate

special precautions such as groundwater or

other geotechnical processes;

• whether the nature of the excavated material

will change;

• whether the excavated materials can be re-

used as backfill to pipework;

• whether any of the soil or groundwater is

contaminated, therefore requiring special

controls on excavation, movement, disposal,

and additional safety measures;

• whether environmental or ecological

considerations might impose any constraints

on the scope of the new works.

On the design side, it is necessary to assess such

considerations as bearing capacity and settlement of

foundations, stability of pipe trenches, earth

pressures on supporting structures, and the effect of

any chemically aggressive or hazardous ground

conditions.

Groundwater control is also a key aspect of

drainage design. Guidance on groundwater

considerations and hydrogeological investigations

are given in Sections 2.6, 3.2 and 4.2 of this

Volume.

For the design of new works, it is important that the

range of conditions, including least favourable

conditions, should be known. This entails not only a

study of the degree of variability in the strata over

the area of the site, but also an appreciation of the

possible injurious effects of groundwater variation

and weather conditions on the properties of the

various strata. Where works require excavations into

or within rock, the orientation and nature of

discontinuities in the rock may be the most important

factor.




3.1.5 Extent of Ground Investigation

The extent of the ground investigation is determined

by the character and variability of the ground and

groundwater, the type of sewerage and drainage

works, and the amount and quality of existing

information. It is important that the general character

and variability of the ground be established before

deciding on the basic principles of the design of the

works.

A range of methods is used to carry out ground

investigations for sewerage and drainage works.

These include excavations, boreholes and probing.

The greater the natural variability of the ground, the

greater the extent of the ground investigation

required to obtain an indication of the character of

the ground. The depth of exploration is usually

determined by the depth of sewerage and drainage

works, but it may be necessary to explore to greater

depths at a number of points to establish the overall

geological structure. The technical development of

the project should be kept under continuous review

since decisions on the design influence the extent of

the investigation.

The investigation should yield sufficient data on

which to base an adequate and economical design

of the project. It should, in addition, be sufficient to

be able to decide which of the various possible

methods of construction would be desirable and,

where appropriate, to suggest sources of

construction materials. The lateral and vertical

extent of the investigation should cover all ground

that may be significantly affected by the new works

or their construction.

3.1.6 Field Works

Successful ground investigation requires careful

advance planning to be conducted in the most

expedient manner. Proper exploratory location

selection and preparation are essential to minimise

site operational standby time and associated

charges. Utility clearance is an essential item that

must be considered. Disrupted utilities can result in

a tremendous liability to all parties concerned. The

following are some detailed items to consider prior

to commencing field works:

• Site preparation;

• Access;

• Utility clearance;

• Traffic control;

• Mechanical excavator and borehole/core drill

equipment and their impact on groundwater

profiles;

• Probing;

• Geophysical surveying;

• Groundwater;

• Barge work;

• Trial pit/drill hole filling.

Site preparation - Drilling sites need to be prepared

prior to arrival of the drill crew to avoid standing

time. A levelled terrain or working platform is often

necessary to accommodate the drill rig, particularly

where the site is at or adjacent to any excavation or

slope formed by other construction activities. Prior

to site work, consultation should be made with the

drilling operatives for specific site preparation

requirements.

Overhead clearance - Overhead must be clear of

obstructions. It is not safe to work adjacent to an

overhead power. Consultation should be made with

the Power Company to determine the minimum

standoff distance from overhead power. If it is

necessary to work closer, the Power Company must

be contacted in order to cut the power during site

works period.

Underground utility locations must be determined,

including:

• High pressure gas lines;

• Water lines;

• Sewer and storm sewer lines;

• Electrical and telephone conduits and

cables.

All locations proposed for drilling must be cleared for

utilities prior to arrival of the drill crew. When utilities

are present, their exact location should be clearly

marked by the utility company. The drilling operative

must verify the locations of underground utility on

site prior to drilling.




Access permit must be secured from the land

owner to ensure that the drill crew has access to drill

sites upon arrival to avoid difficulties associated with

farm animals and uncooperative landowners, for

instance.

Traffic control may be required where the

investigation location is adjacent to highways /

public roads.

Shallow trial pits are usually dug using a hydraulic

backhoe excavator, preferably mounted on a tractor

for ease of mobility. This expedient is used in

ground that can temporarily stand unsupported and

in suitable conditions. For practical reasons, the

maximum depth of excavation is 4m to 5m. Where

personnel are required to enter pits, it is essential

that the sides are safe or made safe, particularly

from sudden collapse, by supporting the sides.

Ideally, the support system should consist of

purpose-made metal frames that can be quickly

inserted and extracted. Entry by personnel into

unsupported pits deeper than 1.2m is not allowed for

health and safety reasons.

By providing access for taking samples and carrying

out in-situ tests, shallow trial pits permit the in-situ

condition of the ground to be examined in detail both

laterally and vertically; they also provide a means of

determining the orientation of discontinuities in the

ground. The field record should include a plan giving

the location and orientation of the pit with details of

which face(s) was logged, and a dimensioned

section of each side and the floor. Whenever

possible, the record should include photographs.

Shallow pits without side support can be used for

making a rapid check on the condition of the ground.

It may be unsafe for personnel to enter a pit but,

working from ground surface, a visual log of the

strata can be made and disturbed samples using the

excavator bucket can be taken.

Tube samplers can be driven into the floor of the pit,

using jarring link and drill rods, and then extracted

by the excavator. In-situ testing, such as the vane

shear strength test, can also be carried out. Pits that

are unsupported may collapse soon after being dug,

so any logging, sampling and in-situ testing should

be carried out immediately after the pit has been

dug. It is advisable to backfill pits as soon as

possible after logging, sampling and testing have

been completed, since open pits can be a hazard to

the general public.

Light cable percussion boring is an adaptation of

standard well-boring methods, and normally uses a

mobile rig specially designed for ground

investigation work.

The clay cutter is used in cohesive soil in a damp or

dry borehole. The shell is used in cohesionless soils

and requires there to be sufficient water in the

bottom of the borehole to cover the shell (about

2.5m). It is therefore necessary to add water to a

borehole in order to bore through dry cohesionless

strata that require the use of the shell.

Light cable percussion boring is suitable for soil and

weak rock. The sizes of borehole casings and tools

are usually 150mm and 200mm. For deeper

boreholes, 250mm and 300mm are available. This

gives a maximum borehole depth of about 60m in

suitable strata. This type of rig may have a hydraulic

power take-off to drive a rotary drilling attachment

for coring rock. The drill tools, which are worked on

a wire rope using the clutch of the winch for the

percussive action, consist of the clay cutter for dry

cohesive soils, the shell or baler, for cohesionless

soils and the chisel for breaking up rock and other

hard layers. The clay cutter and shell bring up

disturbed material, which is usually sufficiently

representative to permit identification of the strata.

Mechanical augers for ground investigations

normally use a continuous-flight auger with a hollow

stem and these are suitable for auguring in cohesive

soils. When auguring, the hollow stem is closed at

its lower end by a plug, which may be removed so

that the sampler can be lowered down through the

stem and driven into the soil below the auger bit.

The use of hollow-stemmed augers in cohesionless

soils often presents practical problems because it

may be difficult to prevent material from flowing into

the hollow stem on removal of the plug.

When rock is encountered, boring can be extended

by core-drilling through the hollow stem. Typically,

augers with hollow stems of approximately 75mm

and 125mm diameter produce boreholes of about

150mm and 250mm diameter respectively, to a

depth of 30m to 50m.




Continuous-flight auguring requires considerable

mechanical power and weight so that the machine is

therefore usually mounted on a heavy vehicle. The

debris from drilling is brought to the surface by

auger flights and gives only a very rough indication

of the levels and character of the strata. A precise

intermittent identification of the strata may be

obtained from drive samples taken through the

hollow stem of the auger.

In self-supporting strata, solid rods and a suitable

auger tool can be used, the auger tool being drawn

up to the ground surface each time it has to be

emptied. Drive sampling and testing can be carried

out in the borehole.

Rotary drilling methods, in which the drill bit is

rotated on the bottom of the borehole, are used to

drill rocks and sometimes soils for investigation

purposes. The drilling fluid, which is passed from the

surface through hollow drill rods to the face of the

bit, cools and lubricates the bit, transports drill

cuttings to the ground surface and, when using

particular types of drilling fluids, stabilises the

borehole.

Drilling fluids are commonly clean water, air, or a

mixture of both. In some cases mud, polymers or

foam are used to maintain or assist borehole

stability, aid the transport of drill cuttings to the

surface and maximise core recovery, particularly in

superficial deposits and weak rock formations. It is

essential that the cleaning and recirculation of the

drill fluid is arranged so that the cuttings transported

from the bottom of the borehole are not recirculated

and that the condition of the drill fluid is maintained

to achieve its objectives.

There are two basic types of rotary drilling: open

hole (or full hole) drilling, where the drill bit cuts all

the material within the diameter of the borehole; and

core drilling, where an annular bit, fixed to the

bottom of the outer rotating tube of a core barrel,

cuts a core, which is recovered within the innermost

tube of the core barrel assembly and brought to the

surface for examination and testing.

Rotary drilling for ground investigation is usually

core drilling. When open hole drilling or coring,

temporary casing is normally used to support

unstable ground or to seal off fissures or voids,

which cause excessive loss of drilling fluid. Drilling

fluid additives or cement grouting may sometimes

be satisfactory alternatives. The rotary drilling rig

should be well maintained and should be capable

both of controlling rotational speed and providing

axial load and torque to suit the nature and

hardness of the material penetrated, the diameter of

the core barrel and drill string, drilling fluid and

flushing system, weight of drill string and installation

of temporary casing(s).

Probing and penetration testing - Probing from

the surface probably represents the oldest method

of investigating the depth to a hard stratum where

the overburden is weak and not unduly thick. The

simplest probe is a sharpened steel rod, which is

pushed or driven into the soil until it meets

resistance. The method is still of use where other

means of site investigation have disclosed relatively

thin layers of very soft soils overlying much harder

ones, when the thickness of the soft stratum may be

determined over a wide area very quickly and

economically. Two distinct types of probe have been

developed: one where the probe is driven into the

soil by means of some form of hammer blow; and

the other where the probe is forced into the soil by a

static load.

Dynamic probing - The apparatus for dynamic

probing comprises a sectional rod with a cone fitted

at the base of a slightly greater diameter than the

rod. It is driven into the ground by a constant mass

that is allowed to fall on the rod through a constant

distance, and the arrangement should be such that

the mass falls through the constant distance without

judgement to be made by the operator. This is

usually achieved using a mechanical latch on

machine-driven equipment, and mechanical

indication on hand-operated apparatus.

The main uses of dynamic probing are for

preliminary investigations of a site using hand-

operated equipment, followed by machine-operated

equipment during the main investigations, thereby

allowing the interpolation of data between boreholes

using site specific correlations with known ground

property data. Where a site investigation has been

carried out by more conventional means, it may be

possible to use dynamic probing to check rapidly

and cheaply that conditions on neighbouring sites

are similar.

Static cone penetration test or static probing -

The basic principle of static probing is that a




cylindrical probe, fitted to the lower end of a string of

hollow rods, is pushed into the ground at a slow

uniform rate by a static thrust. The probe has a cone

at its base, which is fitted with a sensor, so that its

resistance to penetration can be measured. If

required, probes can also incorporate a friction

sleeve, by which the local frictional resistance can

be measured, and also a piezometer for measuring

the pore water pressure in the vicinity of the cone

and sleeve. The most frequently used probe has

electrical sensors, which can permit continuous

recording throughout the test.

Mechanical penetrometers are occasionally used in

very isolated sites, where the more sophisticated

electrical read-out systems are not readily

applicable, and employed as preliminary probing to

assess whether the ground conditions are suitable

for the use of the much more expensive electrical

probe.

Geophysical surveying - The primary objectives in

the use of engineering geophysical surveys in

sewerage and drainage works are:

• Geological investigation: geophysical

methods have a major role to play in

mapping geological boundaries between

layers; determining the thickness of

superficial deposits and depth to rockhead;

establishing weathering profiles; and the

study of particular erosional and structural

features, such as the location of buried

channels, faults, dykes, etc.;

• Hazard assessment: detection of voids and

buried artefacts; location of buried

mineshafts and adits, natural cavities, old

foundations, pipelines etc.; detection of leaks

in barriers; pollution plumes on landfill sites;

• Determination of engineering properties of

the ground, such as dynamic elastic moduli,

rock rippability and rock quality; soil

corrosivity for pipeline protection studies etc.

There are many different geophysical techniques,

each based on different theoretical principles, such

as seismic velocity or electrical resistivity, and

consequently producing different sets of information

relating to the properties of subsurface materials.

For any given geophysical technique the variations

in the information obtained can give an indication of

the geological structure. Invariably interpretation of

geophysical survey data involves some degree of

prior knowledge of the underlying geological

structure derived from the preliminary

reconnaissance and from boreholes. For optimum

interpretation of the data from a geophysical survey

it is essential that adequate direct control is

available, such as boreholes or trial pits. In

comparison with borehole investigations,

geophysical surveys can offer considerable savings

in both time and money.

On sites where contamination is suspected, a

geophysical survey may form part of a preliminary

risk assessment prior to drilling or sampling. During

the drilling programme on the site, geophysical

surveys may be used to check the interpretation of

the geological structure between the boreholes.

Later in the site investigation further geophysical

surveys may be carried out within and between the

boreholes and on the ground surface; these are to

determine the geological, hydrogeological and

geotechnical properties of the ground mass in which

the construction is taking place.

The performance of all geophysical methods used in

site investigation is influenced by four fundamental

controlling factors:

• depth penetration;

• vertical and lateral resolution;

• signal-to-noise ratio;

• contrast in physical properties.

Prior to the employment of geophysical methods, it

is necessary to determine the quality of information

required, taking the above four factors into

consideration, in order to yield an effective

investigation.

Groundwater - The determination of groundwater

pressures is of the utmost importance, because

these have a profound influence on the behaviour of

the ground during and after the construction of

engineering works. Various strata, particularly those

separated by relatively impermeable layers, can

have different groundwater pressures, some of

which may be artesian. The location of highly

permeable water-bearing strata and the

measurement of water pressure in each is

particularly important where deep excavation or




tunnelling is required, since special measures may

be necessary to deal with the groundwater. To

measure groundwater pressures accurately, it is

usually necessary to install special measuring

devices called piezometers.

The groundwater pressure may vary with time owing

to seasonal, tidal, or other causes, and it may be

necessary to take measurements over an extended

period of time so that such variations may be

investigated. When designing drainage works, it is

often helpful to determine the contours of the water

table or piezometric surface to ascertain the

direction of the natural drainage, the seasonal

variation and the hydrological controls.

Borehole permeability tests and large scale pump

tests should be considered. These tests require

some flow of water into or out of the measuring

system before the recorded pressure can reach

equilibrium with the actual groundwater pressure.

For an excavation or a borehole, a large volume of

water may flow before the water level reaches

equilibrium with the groundwater pressure. On the

other hand, some types of piezometer require only a

very small change in the volume of water for the

groundwater pressure to be read. The rate at which

water flows through the soil depends on the

permeability. The time required for a measuring

system to indicate the true groundwater pressure is

known as the response time and depends both on

the quantity of water required to enter the system

(including all pipes and tubes) to operate the

pressure measuring device, and on the permeability

of the ground. Depending on the response time, a

suitable method for measuring the groundwater

pressure should be employed.

Barge work - When the sewerage must cross large

bodies of water, barges are used to obtain ground

information. Sufficient lead-in time must be allowed

for mobilisation of barges.

Trial pit/drill hole filling - Upon completion of trial

pitting works, the pits should be filled and

compacted to better than its original conditions. If

the materials arising from the trial pits could not be

compacted (e.g. some silty or clayey soils), then the

arising should be disposal off site and the pit be

filled with imported materials.

Drill holes must be filled or plugged. This prevents

injury to livestock or people in the area and also

minimises the entry of surface water into the

borehole. If surface contamination of lower aquifers

or cross contamination is a concern, backfill the hole

with bentonite pellets or grout. This is especially

important in urban areas where ground

contamination from leaking underground storage

tanks is a common occurrence.

3.1.7 Sampling

The selection of sampling technique depends on the

quality of the sample that is required and the

character of the ground, particularly the extent to

which it is disturbed by the sampling process.

There are four main techniques for obtaining

samples:

• taking disturbed samples from the drill tools

or from excavating equipment in the course

of boring or excavation;

• drive sampling, in which a tube or split tube

sampler having a sharp cutting edge at its

lower end is forced into the ground, either by

a static thrust or by dynamic impact;

• rotary sampling, in which a tube with a cutter

at its lower end is rotated into the ground,

thereby producing a core sample;

• taking block samples specially cut by hand

from a trial pit.

Samples obtained by techniques as noted in the

second, third and fourth points above are often of

sufficient quality to enable the ground structure

within the sample to be examined. The quality of

such samples can vary considerably, depending on

the technique and the ground conditions, and most

exhibit some degree of disturbance.

When taking samples for chemical testing and in

particular, on potentially contaminated sites,

additional care is needed to avoid cross-

contamination and chemical or biological reactions,

which may affect the result. The risks of cross-

contamination are reduced by:

• using dry drilling or air flush methods for

progressing the boreholes;

• using casing to isolate upper layers of soil

and groundwater;




• ensuring that all sampling and boring

equipment are clean;

• implementing strict sample handling

protocols.

Any sample of ground that might be contaminated

by substances hazardous to health should have a

warning to that effect on the sample label so that

personnel can follow appropriate safety procedures.

Sampling in sand and gravel should be carried out

at the top of each new stratum and thereafter at

1.5m interval of depth; a disturbed sample should be

obtained from a split-barrel sampler.

Sampling in cohesive soil should be carried out at

the top of each new stratum and thereafter at 1.5m

intervals of depth for undisturbed samples, and at

each metre of depth, a disturbed sample should be

obtained.

If with the sampler there is inadequate recovery or

the sampler cannot be driven, this should

immediately be followed by a standard penetration

test using a split-barrel sampler.

Sampling in rock should use continuous rotary

core. In cases where the core recovery is poor and

the rock is weak, the split-barrel standard

penetration test sampler should be used after each

core run in an attempt to recover a small sample of

the rock. Depending on the rock type, it may also be

useful to take a disturbed sample from the drill fluid

return, and thereafter at 1 m intervals of depth.

Handling and labelling of samples - Samples

obtained should be treated with great care. The

usefulness of the results of the laboratory tests

depends on the quality of the samples at the time

they are tested, so it is important to establish a

satisfactory procedure for the handling and labelling

of the samples, as well as their storage and

transport both to prevent their deterioration, and to

ensure that they can be readily identified and drawn

from the sample store when required.

The samples should be protected from excessive

heat and temperature variation, which could lead to

deterioration in the sealing of the sample containers

and subsequently damage the samples. The

temperature of the sample store is influenced by the

climate, but it is recommended that the samples be

stored at the lowest temperature practicable and

below 450C. The daily temperature variation within

the store should not exceed 200C.

All samples should be labelled with a unique

reference number immediately after being taken

from a borehole or excavation. If they are to be

preserved with their natural moisture content, they

should be sealed in an airtight container or coated in

wax at the same time. The label should show all

necessary information about the sample. If the

sample is of ground which might be contaminated

and contain hazardous substances, then the label

should carry a warning to that effect. The sample is

normally recorded on the daily field report. It should

carry more than one label or other means of

identification so that the sample can still be identified

if one label is damaged. The label should be marked

with indelible ink and be sufficiently robust to

withstand the effect of its environment and the

transport of the sample. An additional record copy of

the sample should also be kept separately.

Disturbed samples of soil and hand specimens of

rock may be required for testing, or where it is

desirable to keep them in good condition over long

periods for later inspection. Immediately after being

taken from a borehole or excavation, the sample

should be placed in a glass container of at least 1

litre capacity, which the sample should fill with the

minimum of air space. The container should have an

airtight cover or seal so that the natural moisture

content of the sample can be maintained until tested

in the laboratory. The sample containers should be

labelled. For rock samples, an alternative procedure

is to coat the sample in a layer of paraffin wax. A

microcrystalline wax is preferred because it is less

likely to shrink or crack. Larger disturbed samples

that are required for certain laboratory tests may be

packed in robust containers or plastic sacks. For

hand samples of rock, the reference number should

be recorded by painting directly on the surface of the

sample or attaching a label. Samples should then be

wrapped in several thicknesses of paper and packed

in a wooden box.

During the interval when the samples are on site or

in transit to the sample store, they should be

protected from excessive heat.

For Undisturbed samples that are retained in a

tube or liner, procedure a) below should be followed.




For other samples, procedure b) below should be

followed:

a) Immediately after the sample has been taken

from the boring or excavation, the ends of the

sample should be removed to a depth of about

25mm and any obviously disturbed soil in the

top of the sampler should also be removed.

Several layers of molten wax, preferably

microcrystalline wax, should then be applied to

each end to give a plug of about 25mm in

thickness. The molten wax should be as cool

as possible. It is essential that the sides of the

tube be clean and free from adhering soil. If the

sample is very porous, a layer of waxed paper

should first be placed over the end of the

sample. Any remaining space between the end

of the tube or liner and the wax should be

tightly packed with a material that is less

compressible than the sample and not capable

of extracting water from it. There should be a

close-fitting lid or screw-cap on each end of the

tube or liner. If necessary, the lids should be

held in position with adhesive tape.

b) Immediately after being removed from the

sampling tool, samples that are not retained in

a tube should be wholly covered with several

layers of molten paraffin wax, preferably

microcrystalline wax, and these should then be

tightly packed with a suitable material into a

metal or plastics container. The lid of the

container should be held in position with

adhesive tape. If the sample is very porous, it

may be necessary to cover it with waxed paper

before applying the molten wax.

The liners or containers should be packed in a

way that minimises damage by vibration and

shock during transit.

Rotary core samples should be kept in a sample

store as described above.

Block samples - After labels have been attached to

the sample to indicate its location and orientation the

sample should be coated with a succession of layers

of microcrystalline wax. It may be advisable to

reinforce these with layers of porous fabric (e.g.

muslin) or plastic film. Additional labels should be

fixed to the outside of samples. The sample should

be packed in a suitable material and placed in a

strong box or crate. Large samples should be

protected with tight-fitting formwork or packed in

rigid cement, wax or resin to prevent fissures from

opening up under the weight of the samples.

Groundwater samples - Care should be taken to

ensure that the samples are representative of the

water-bearing stratum and have not been

contaminated or diluted by water entering the

borehole from other strata, or by contact with any

water or drilling fluid used to advance the borehole.

The depth and method of sampling, as well as the

subsequent storage and handling of samples, may

influence the results of analyses undertaken on

groundwater samples.

Sample containers should be made from glass,

polyethylene or polypropylene, be clean and

completely filled with the water sample so as to

minimise contact with oxygen. The samples should

be stored in the dark, at low temperatures and

tested as soon as possible after sampling.

When groundwater samples are to be taken from a

stratum that has been contacted while advancing

the borehole, all water-bearing strata from higher

levels should first be sealed off by borehole casings.

As far as possible, all the water in the borehole

should be removed by baling or pumping and the

sample taken from water that collects by seepage.

About one litre should be collected in a clean

polyethylene, polypropylene or glass bottle, which

should be rinsed three times with the water being

sampled before filling.

More stringent requirements may apply in certain

circumstances, particularly when accurate or

extensive chemical testing is to be undertaken in

order to investigate possible chemical

contamination. Additional requirements may include

special sampling techniques, multiple samples in

different sample containers with different fixing

agents, duplicate sampling, and special sample

handling procedures.

Some investigations require the use of permanent

monitoring wells from which groundwater samples

can be taken at various times. Before taking a

sample, it is essential that the well be purged, i.e.

the water standing in the well is removed by baling

or pumping, and groundwater allowed to flow in until

the water in the standpipe is representative of the




groundwater. The sample is then taken using a baler

type sampler or a suitable pump.

3.1.8 Field Tests

During ground investigation field works, in-situ tests

in boreholes should be carried out concurrent with

soil/rock sampling. Numerous tests in boreholes

have been developed. Routine tests that are

considered relevant to sewerage and drainage

design include:

• Standard penetration test;

• Vane test;

• Permeability test;

• Packer test.

Other specialist tests in boreholes, e.g. plate load

tests, or pressure meter tests may be relevant to

foundation design of pumping stations and tunnels.

These tests should also be considered as

appropriate.

In addition to tests performed in boreholes, pump

tests may also be relevant to sewerage and

drainage works, particularly for the design and

construction of deep shafts where the mass

permeability of the ground and its groundwater

response to pumping during construction phases.

Other in-situ tests, including field density, in-situ

stress measurement, lateral and inclined loading

tests, pressurised chamber tests, and in-situ shear

tests are not usually employed for sewerage and

drainage works. However, the merits of these tests

may be relevant to particular sites and design

requirements.

Standard penetration test is a dynamic penetration

test carried out using a standard procedure, which is

described in BS 1377-9:1990, 3.3. The test uses a

thick-walled sample tube, the outside diameter of

which is 50mm. This is driven into the ground at the

bottom of the borehole by blows from a standard

weight falling through a standard distance. The blow

count gives an indication of the density of the

ground. The small sample that is recovered will have

suffered some disturbance but can normally be used

for identification purposes.

When the test is being performed in gravel of

coarser soil or in rock, the cutting shoe of the split-

barrel sampler may be replaced by a solid cone of

the same outside diameter and an included angle of

600. It is important that the test is carried out

precisely as described in BS 1377-9:1990, 3.3, since

even minor variations from the specified procedure

can seriously affect the results and its interpretation.

The main purpose of the test is to obtain an

indication of the relative density of sands and

gravels, but it has also been used to find out the

consistency of other soils (silts and clays) and of

weak rocks (e.g. chalk).

In sand and gravel, at the top of each new stratum,

and thereafter at one metre intervals of depth, a

standard penetration test should be carried out.

In cohesive soil, when the recovery of samples from

the sampler is inadequate or the sampler cannot be

driven, a standard penetration test using a split

barrel sampler should be carried out.

Vane test - A cruciform vane on the end of a solid

rod is forced into the soil below the bottom of the

borehole and then rotated. The torque required to

rotate the vane can be related to the shear strength

of the soil. The method of carrying out the test is

described in BS 1377-9:1990, 4.4.

The test can be extended to measure the remoulded

strength of the soil. This is done by removing the

torque-measuring instrument from the extension

rods and turning the vane through six complete

rotations. A period of five minutes is permitted to

elapse after which the vane test is repeated in the

normal way.

The test is normally restricted to fairly uniform,

cohesive, fully saturated soils, and is used mainly for

clay having undrained shear strength up to about

100 kPa. Results are unreliable in materials with

significant coarse silt or sand content.

Permeability tests are carried out in boreholes to

determine the hydraulic conductivity, a measure of

the rate of water flow of soils.

Before carrying out any tests, it is important to

identify the aquifer and understand whether it is

confined or unconfined. The determination of in-situ

permeability by tests in boreholes involves the

application of a hydraulic pressure in the borehole

different from that in the ground, and the




measurement of the rate of flow due to this

difference.

The pressure in the borehole may be increased by

introducing water into it, which is commonly called a

“falling head” test, or it may be decreased by

pumping water out of it in a “rising head” test. The

pressure may be held constant during a test

(constant head test) or it may be allowed to vary (a

variable head test).

The Packer or Lugeon test gives a measure of the

acceptance by in-situ rock of water under pressure.

In essence, it comprises the measurement of the

volume of water that can escape from an uncased

section of borehole in a given time under a given

pressure. Flow is confined between known depths

by means of packers, hence the more general name

of the test.

The flow is confined between two packers in the

double packer test, or between one packer and the

bottom of the borehole in the single packer test. The

test is used to assess the amount of grout that rock

accepts, to check the effectiveness of grouting, to

obtain a measure of the amount of fracturing of rock,

or to give an approximate value of the permeability

of the rock mass local to the borehole.

The results of the test are usually expressed in

terms of Lugeon units. A rock is said to have a

permeability of 1 Lugeon if, under a head above

groundwater level of 100m, a 1m length of borehole

accepts 1l/min of water. A simple rule that is

sometimes used to convert Lugeon units into

permeability is to take one Lugeon unit as equal to a

permeability of 1027m/s.

Pump test - In principle, a pumping test involves

pumping at a steady known flow from a well and

observing the drawdown effect on ground water

levels at some distance away from the pumped well.

In response to pumping, phreatic and piezometric

levels around the pumping well fall, creating a “cone

of depression”. The permeability of the ground is

obtained by a study of the shape of the cone of

depression, which is indicated by the water levels in

the surrounding observation wells.

The shape of the cone of depression depends on:

the pumping rate; the duration of pumping; the

nature of the ground; the existence, or otherwise, of

intermediate or other boundaries; the shape of the

ground water table; and nature of recharge. From

the data obtained from the test, the coefficients of

permeability, transmissivity and storage can be

determined.

The results obtained are averages for the entire

mass of ground which has been influenced by the

pumping test. In permeable ground, pumping from

the well may have a significant effect on piezometric

pressures to a distance of 100m or more. Flows

from a well pumping test are accumulated from

contributions coming from strata that may have very

different values of permeability individually and may

not be of consistent thickness within the radius of

influence of the well. The overall result could be

dominated by the flow from one highly permeable

layer or discontinuity; hence a thorough

understanding of the geological sequence of the

ground is vital in the interpretation of the pump test

results.

3.1.9 Laboratory Tests

Soil and water samples obtained from the field

works should be tested to evaluate their engineering

properties and to complement field observations.

Before samples are passed to the laboratory, care

should be taken to assess the possibility that some

may be contaminated with harmful substances. If

such a possibility exists, appropriate safety

precautions should be implemented and preliminary

tests done to determine the nature of any

contamination. The results of these preliminary tests

establish whether it is necessary to impose any

special procedures to ensure the safety of the

laboratory personnel.

The purpose of laboratory testing of samples of soil

and rock is to determine the following properties:

• Classification;

• chemical and electro-chemical;

• soil corrosivity;

• compaction-related properties;

• compressibility;

• permeability and durability;

• shear strength (total stress and effective

stress).




The selection of tests depends on the design

requirements. It is often not necessary to specify

the whole range of tests listed above. Conversely, it

is essential to assign appropriate tests to be

undertaken, as late schedule of tests may adversely

impact on the design and construction programme.

Classification tests are used to determine the

following characteristic properties of soil/rock

samples:

• Moisture content or water content;

• Suction for desiccated soils;

• Liquid and plastic limits (Atterberg Limits);

• Soil volumetric shrinkage limit;

• Soil linear shrinkage;

• Swelling clay content;

• Soil particle density;

• Mass density or unit weight;

• Soil particle size distribution.

Soil suction, volumetric shrinkage, linear shrinkage,

and swell clay content tests are not usually required.

Particle density test is required occasionally to verify

the commonly adopted value of 2.65 is valid.

Chemical and electro-chemical tests are used to

determine the following properties of soil/rock and

water samples:

• Dispersion for fine grained soils;

• Chemical contaminants for soils and water;

• Organic matter in soils, in particular, peats;

• Sulphate content of soil and ground water;

• Magnesium content as a supplement to the

sulphate content test to assess the

aggressiveness of soil or groundwater to

buried concrete;

• pH value for soils and water;

• Carbonate content to determine the

presence of carbonates, which often

indicates cementing;

• Chloride content, where pH of ground is less

than 5.8. Results are used in conjunction

with those for sulphate, nitrate and pH to

assess the aggressiveness of the ground,

especially to concrete;

• Total dissolved solids in groundwater.

Soil corrosivity is determined by bacteriological,

Redox potential, and Resistivity tests on undisturbed

specimens stored in sterilised containers.

Compaction tests require the determination of dry

density; standard compaction tests at different

moisture contents and compaction efforts;

maximum, minimum density and density index tests

of coarse grained soil; and moisture condition value

used for control of materials for earthworks.

Compressibility tests include: one-dimensional

compression and consolidation tests to determine

the coefficient of volumetric changes and the

coefficient of consolidation.

Permeability and durability tests include: constant

head tests; falling head tests; triaxial permeability

tests; and Row consolidation tests.

Strength tests for soils include: triaxial compression

tests, unconfined compression tests; laboratory

shear vane tests; direct shear box; and residual

shear strength tests. Strength tests for rocks

include: point load tests; uniaxial compression tests;

direct and indirect tension tests; and triaxial

compression tests.

3.1.10 Reports and Interpretation

Reports on ground investigation should distinguish

between factual report and interpretative report.

Factual reports should record all information

obtained from the actual ground investigation carried

out. This includes results from field and laboratory

works.

Interpretative reports should contain all information

obtained from desk study and site reconnaissance,

and interpretation of the data contained in the

factual report. Often it is convenient to produce

separate desk study reports and interpretative

reports. In such cases, references to relevant desk

study reports should be made in the interpretative

reports.

Factual Report




The content of a factual report should include the

following (not necessary exhaustive):

• Introduction

This should state who the client is the works

were undertaken for, the dates and nature of

the investigation, the nature of the proposed

development for which the investigation was

carried out, and the general location.

• Site description

The report should contain a description of

the geographical location of the site and

comment on features outside the site

boundary. Where appropriate this should

include street names and grid reference. It

may also include a reproduced section of the

relevant map of the appropriate scale for

clarity. Details of all relevant topographic

features should be included. The description

should also include details of what was

present on the site at the time of the

investigation, including the possibility or

knowledge of any contaminated ground or

landfill gases. In addition, details of any past

or present man-made underground features,

such as basements, mineral or other

extractive workings, access or drainage adits

and other tunnels, should be included. Some

comment should be made on the relative

levels between the site and its surroundings,

and whether there are conspicuous

differences in level over the site itself.

• General geology

An account should be given of the geology

of the site, and the sources from which the

information was obtained should be stated.

Information from previous ground

investigations on or adjacent to the site

should be emphasised. The soil and rock

types identified and described in the report

should be linked with the known geology of

the site.

• Fieldwork

This should describe the methods of

investigation and testing used. It should

include a description of all the equipment

used, e.g. types of drilling rigs and tools,

together with the relevant standards for

testing, sampling or drilling to which the work

has been carried out. A note should be

made of any difficulties experienced, e.g.

problems in recovering samples. It is

essential that any testing for gases and other

contaminants, or observations of these in the

boreholes and around the site generally be

reported. The dates when the exploratory

work was done should also be recorded,

together with a note about the weather

conditions, if relevant. The report should

contain a drawing indicating the positions

and ground levels of all pits, boreholes, field

tests, etc. It should contain sufficient

topographical information so that the several

positions can be located at a later date.

• Exploratory hole (including trial pit) logs.

Logs of exploratory holes should contain the

following data as a minimum:

1) title of investigation, report number,

and name of client;

2) location detailed by a national or site

grid reference;

3) date of start and finish of boring;

4) unique borehole number;

5) type of boring, e.g. cable, percussion

or rotary, and other details, including

sizes of boring tools or drilling

equipment used;

6) ground level related to recognised

national datum;

7) diameter of borehole and/or types of

core barrel including depths of any

reductions in size;

8) diameter of casings and depth to

which taken;

9) a depth scale so that the depth of

sampling, tests and change in strata

can be readily determined;

10) a description of each stratum

together with its thickness. For trial

pits, a record of the ease of

excavation of the strata and stability

of the sides of the excavation should

be taken. Soils and rocks should be

described in accordance with Table




A6.1 and A6.2, and with symbols as

given in Table A6.3 (see Appendix

6).

11) the depth and level of each change

of stratum;

12) the depth of the top and bottom of

each tube sample, or bulk sample

and its and the depth of each small

disturbed sample; or the depth of the

start and finish of each core run; the

core recovery for each rock core run

expressed in percentage of total core

recovery, the fracture state

expressed in terms of rock quality

designation, solid core recovery, and

fracture index; zones of core loss

and voids; rock cores, cores should

be photographed when fresh and

before any destructive logging is

carried out. The photographs should

be in colour, to a consistent format

on any investigation, include job,

borehole and depth references,

together with a scale and standard

colour chart, and be free from

distortion. The photographs should

be presented in the report.

13) the depth at the top and bottom of

each borehole test and the nature of

the test;

14) where standard penetration tests are

being recorded, tests made with the

thick-walled sampler should be

distinguished from those made with

a solid cone; and should include all

incremental blow counts and

penetrations;

15) the date when each section was

bored or cored/drilled;

16) details of tools in use, including

sizes; for trial pits, a description of

excavator type, bucket size, shoring

arrangement and pumps as

appropriate;

17) an indication of the type of drilling

flush and return proportion for each

core run, with note of any change in

colour;

18) water levels (including changes) and

related casing depths at all samples,

tests and water inflows; incidence

and behaviour of groundwater.

Where no groundwater was

encountered, this should also be

recorded. In addition, where

groundwater observations could not

be observed this should be noted; for

instance, drilling with water flush or

over water, or boring at a rate much

faster than water can make its way

into the borehole. Where the

information derived from boreholes is

concise, it should be included in the

logs. The position of the borehole

casing and the borehole depth at the

time of an observation should be

stated. All other data, including those

from separate observation wells,

should be given in a separate table.

Where water has been added to or

removed from the ground by the

boring or drilling process, this should

be recorded.

19) a record of each water strike,

including rate of rise of water level,

depth of water in the borehole at

start and finish of shift, depth of

water at the time of each test or

sample and depth of casing when

each observation was made. The

final reading to be determined after a

minimum of 3 readings at 24 hour

intervals, when steady state has

been reached;

20) a record of any water added to

facilitate boring;

21) where observation wells or

piezometers have been installed,

their depths should be given,

together with details of the

installation, preferably in the form of

a diagram, and often on a separate

report sheet;




22) water levels in observation wells

measured subsequent to the

completion of the borehole; these

may be recorded separately.

23) a record of tests carried out, such as

permeability and packer tests;

24) the orientation of the exploratory

holes;

25) depth of termination of borehole;

26) details of backfilling or instruments

installed;

27) ground and surface water records;

28) details of all samples and tests

taken, including depth at top of each

sample; the core recovery for each

rock core run expressed in

percentage of total core recovery,

the fracture state expressed in terms

of rock quality designation, solid core

recovery, and fracture index.

• In-situ tests

In-situ tests should be reported giving full

details of the test type, location, equipment

used, start and finish date and time, weather

conditions, particular difficulties

encountered, and details of the testing

procedure and results obtained.

• Location of exploratory holes and in-situ

tests

These should be indicated on a plan

showing the precise position of each

borehole so that it is possible to locate each

position accurately even after demolitions

and excavations have taken place.

Extensive tracts of open featureless country

present problems that are best solved by

linking the position of the borehole to a land

survey. Ground levels related to a

permanent datum are also required.

• Results of laboratory tests

These should be reported in accordance

with BS 13771. A summary should be

provided in addition to the detailed results.

The precise test carried out should also be

stated.

A description of samples should be given.

Soil and rock samples should be described

in accordance with Table A6.1 and A6.2,

Appendix 6.

• Special reports

Special reports, such as penetration tests,

well-point pumping, and geophysical survey

should be reported separately as

appropriate.

Interpretative Report

The content of an interpretative report should

include the following (not necessary exhaustive):

• Introduction

The Introduction to the interpretative report

should state who was the client for the

proposed scheme, the nature of the

proposed scheme, the contractor who

carried out the field and laboratory works,

the dates and nature of the investigation,

and the general location of the scheme.

References to factual reports should be

made.

• Desk study

Desk study information should be included in

the interpretative report, unless a separate

report has been compiled, in which case a

reference to the desk study report should be

made.

• Ground type and stratigraphy

Ground type and stratigraphy should be

described. Where appropriate, the ground

should be divided into a series of soil and

rock types for which the engineering

properties may be regarded as sensibly

constant for the purpose in hand. This

division is usually, though not always,

closely related to the geological succession.




A description of each ground type should be

given and any anomalies that have been

observed should be noted and commented

on.

An account should be given of the sequence

of ground types as they occur in the various

parts of the site. Wherever possible the

stratigraphy of the site should be tied into its

topographical, geological and

geomorphological features. Attention should

be specifically drawn to any anomalies that

may have a significant effect on the works

being considered.

Discussions on ground type and stratigraphy

should be supplemented by geotechnical

cross-sections illustrating the ground profile,

simplified as required, with groundwater

level shown.

The presentation of a borehole section

would usually include joining up the

boreholes by stratum boundaries, using all

the available information and suitably

qualified in any areas of doubt. Accurate and

integrated interpretation of geological maps,

boreholes and other data is a prerequisite to

a thorough understanding of the ground. It

can be helpful to indicate relevant soil

parameters on sections, e.g., results of

standard penetration tests, triaxial tests or

earthworks relationship tests.

• Geotechnical design parameters

There is no universally accepted method of

selecting these parameters, but the following

approach may help to arrive at reliable

values:

1) compare both laboratory and in-situ

test results with ground descriptions;

2) cross-check, where possible,

laboratory and in-situ results in the

same ground;

3) collect individually acceptable results

for each formation and decide

representative values appropriate to

the number of results;

4) where possible, compare the

representative values with

experience and published data for

similar geological formations;

5) consider and explain apparently

anomalous or extreme results.

• Groundwater

Groundwater is a very important factor in the

design and also in the selection of methods

of construction. Inadequate or erroneous

assessment of groundwater conditions is

one of the biggest single contributors to

problems on-site during construction. The

report should describe regional groundwater

conditions and the presence or otherwise of

perched, artesian or downward draining

conditions. Comment should be made on

any anomalies and the possibility of the rise

or fall of groundwater with the season, tide

or other long term variation. Further

guidance is given in Sections 3.2 and 4.2 in

this Volume.

• Chemical conditions

Comment should be made on chemical

conditions in the ground and groundwater,

not only with regard to attack on buried parts

of the structure, but also with regard to

possible effects in construction and service

life, whether these be due to natural causes

or to human activities. Any conditions that

could affect health and safety during

construction or in subsequent use should be

mentioned.

• Engineering considerations

Engineering considerations should relate to

the nature of the scheme. The following list,

which is by no means exhaustive, indicates

the topics on which advice and

recommendations are often required, and

also what should be included. Given the

availability of a wide and ever-changing

range of proprietary systems, all of which

interact with the ground in subtly different

ways, it is important that the report does not

overstate the technical analysis of the

engineering works in relation to the ground

interactions. However, it is essential for the




report to provide adequate information

needed to assess the suitability of various

design and construction options.

1) Spread foundations: level, either in

terms of a depth or to a stated

stratum; safe or allowable bearing

capacity; estimated total and

differential settlements; possible

alternative types of foundation;

possible ground treatment.

2) Piles: types suited to the ground

profile and environment; estimated

safe working loads, or data from

which they can be assessed;

estimated settlements of structures.

3) Retaining walls: lateral pressures or

data from which they can be derived;

wall friction; bearing capacity;

groundwater conditions.

4) Basements/shafts: comment on the

possibility of flotation. An estimate of

the rise of the basement floor/shaft

base during construction, and where

appropriate, groundwater levels.

5) Ground anchorages: bearing stratum

and estimated safe loads, or data

from which they may be calculated;

6) Chemical attack: most commonly

takes the form of recommendations

for protecting buried concrete

against attack from sulphate-bearing

soils and groundwater. Also to be

considered is the possibility of

corrosion of steel in saline waters or

in the presence of sulphate-reducing

bacteria. The effect of acidic or

highly alkaline soils may also need to

be considered. Contaminated soils,

especially those containing high

concentrations of organic chemicals,

should be considered for their effects

on all building materials, including

effects on services. These factors

should also be considered with

regard to health and safety during

construction and in subsequent use

of the structure.

7) Pavement design: assessment of

appropriate design parameters or

California Bearing Ratios; type and

thickness of pavement; possibility of

using soil stabilisation for forming

pavement bases or sub-bases;

recommendations, where

appropriate, for sub-grade drainage;

comment on susceptibility of soil at

formation level to frost heave.

8) Slope stability: recommendations on

temporary and permanent slopes for

excavations, including where

appropriate, drainage measures.

Comment should be made, where

relevant, on the possibility of

weathering of rock faces and the

available methods of dealing with

this hazard. Recommendations for

the monitoring of unstable slopes

may also be required.

9) Mining subsidence: This is not a

common issue in Qatar. However, if

any voids are identified,

recommendations for methods of

filling known cavities near the

surface; the design of structures to

withstand movements without

damage or measures to limit the

damage and simplify repairs.

10) Tunnels and underground works: a

description of the ground through

which the tunnel is to be driven, by

chainage; possible covering of the

following points: methods and

sequence of excavation; whether

excavation is likely to be stable

without support; suggested methods

of lining in unstable excavations;

potential use of rock bolting;

likelihood of encountering

groundwater and recommendations

for dealing with it; special features

for pressure tunnels; risk of

encountering ground or water

contamination; possibility of natural

or man-made gases.

11) Safety of neighbouring structures: an

assessment of the likely amount of




movement caused by adjacent

excavations and groundwater

lowering, compressed air working,

grouting and ground freezing or

other geotechnical processes. The

possibility of movement due to

increased loading on adjacent

ground may also need to be

considered.

12) Monitoring of movements: comment

on the necessity for measuring the

amount of movement taking place in

structure and slopes, together with

recommendations for the method to

be used; recommendations for taking

photographs before the

commencement of works.

13) Embankments: comment on stability

of embankment foundations and pipe

trenches; assessment of amount and

rate of settlement and the possibility

of hastening it by such means as

vertical drains; recommendations for

side slopes; choice of constructional

materials and methods; parameters

for control of earthworks.

14) Drainage: comment on possible

drainage methods during

construction for works above and

below ground; general permanent

land drainage schemes for extensive

areas.

• Construction expedients

Comments and recommendations are often

required on the points listed below. Safety

aspects should be included where

appropriate. These matters are often given

insufficient attention, although they are

comparable in importance to the design of

the permanent works.

1) Open excavations: method and

sequence of excavation; what

support is needed; how to avoid

boiling and bottom heave; estimated

upward movement of floor of

excavation. Comment on relative

merits of sheet piling and diaphragm

or bored pile walls where

appropriate.

2) Underground excavations: method

and sequence of excavation and the

need for temporary roof and side

support; dealing with gases.

3) Groundwater: likely flow, head and

quantity and how to deal with it.

4) Driven piles, bored piles and ground

anchors: methods of driving or

construction suited to the ground

profile, environment and

neighbouring buildings.

5) Grouting: types of grouts likely to be

successful in the ground and

recommended method of injection.

6) Mechanical improvement of soil

below ground level. Comment on the

suitability of techniques for the

consolidation of loose soils.

7) Contamination: known or suspected

contaminants and gases in soil,

groundwater and any cavities.

Comment on health and safety

aspects both during and after

construction.

8) Sources of materials. The following are suggested:

i) Fill: possibility of using

excavated material for this

purpose as an assessment

of the proportions of usable

material; methods and

standards of compaction;

possible off-site sources of

fill; bulking factor.

ii) Aggregates: in areas

where no commercial

sources are available, the

possibilities of winning and

processing materials

available locally.




3.2 Hydrogeological Investigations

This Section should be read with reference to:

• Section 4.2 (Ground Conditions) which

contains a general review of the

hydrogeological conditions that characterise

Qatar;

• Section 3.1, which describes the

requirement for geotechnical investigations.

There is considerable overlap between the

components of work that make up a geotechnical

investigation and that of a hydrogeological

investigation with much of the data obtained being of

use in both types of interpretation. In addition it is

most cost-effective to combine the two in one

seamless operation.

3.2.1 Purpose of Investigations

In the context of drainage issues, the purpose of a

hydrogeological investigation is to obtain a sufficient

understanding of the groundwater conditions that

characterise an area to enable suitable and cost-

effective drainage solutions to be designed,

constructed, and operated.

3.2.2 Outline Methodology

The recommended methodology is as follows:

Phase 1: Desk Study

• Consider data requirements relevant to the

drainage problem under consideration (e.g.

dewatering, drainage for a single building,

drainage for a larger development, drainage

for a district etc.);

• Procure and review currently available

information on general geological and

hydrogeological conditions;

• Procure and review relevant data on the

area concerned e.g. from previous site

investigations;

• Carry out field visits and reconnaissance

inspections to verify conditions at the site;

• Make a preliminary hydrogeological

interpretation i.e. of the groundwater regime

that characterises the area under current

conditions;

• Make a preliminary assessment of the

possible drainage solutions in the context of

the hydrogeological interpretation;

• Identify uncertainties in the interpretation

that require resolution by further site

investigation;

• Draw up a scope for the additional

investigations, amalgamate the work

required with any geotechnical

investigations, and produce a schedule of

works required for tendering purpose or

other procurement method as required;

• Produce an interim report on findings as

necessary or otherwise record project status

to date for record purposes.

Phase II: Intrusive Investigations

• Procure investigations through tender and

award procedures as appropriate;

• Supervise works to ensure compliance with

specification;

• Take responsibility for (or have provided by

site investigation contractor) factual and

interpretative reports on ground conditions;

• Carry out longer-term monitoring as required

e.g. of groundwater levels and quality;

• Produce final interpretation for detailed

design.

3.2.3 Sources of Information

A considerable amount of work has already been

done to understand the hydrogeological conditions

that characterise Qatar, especially the Greater Doha

area and a summary is given in Section 4.2. The

main source of this information are consultant’s

reports that have been produced, particularly since

1981, mainly for government ministries and their

executive agencies such as the DA. Subsequently,

groundwater investigations have been carried out for

various kinds of infrastructure development and

longer term groundwater level monitoring is

continuing.




The available information includes the results of site

investigations that have produced borehole logs with

detailed strata descriptions. Some investigations

have included determination of key hydrogeological

parameters such as permeability, specific yield and

up-to-date groundwater level information may also

be available.

It follows therefore that there is much more detailed

and possibly site-specific information relevant to a

particular area that may be available in addition to

the general description contained in this manual.

3.2.4 Data Requirements: Desk Study Phase

The following is a summary of information

requirements at Desk Study stage:

• Information relevant to the physical setting,

including; geomorphology, ground elevation

relevant to the surrounding area, proximity to

coastline, and the current extent of urban

development etc.;

• Any information that can be obtained relating

to the functioning of drainage systems in the

new project area e.g. the propensity for

flooding, or the performance of soakaways;

• Geological Information:

1) The strata succession in the 0-50m

depth range;

2) Rock types in the sequence to the

top of the Midra Shale, including

lithological descriptions, extent of

fissuring, and degree of weathering.

• Hydrogeological Information:

1) Rock properties (permeability and

porosity) estimated from lithological

description, if possible supported by

information from previous site

investigations;

2) Groundwater level information

including likely depth to the water

table and its elevation (the latter

providing the basis for deducing

groundwater flow patterns), and the

likely extent of seasonal variation;

3) Indicative information on

groundwater quality, for construction

materials, design purposes and also

as an indicator of the extent of urban

leakage.

The above information will then be collated to

provide a preliminary interpretation of groundwater

conditions with a view to uncertainties being

resolved through additional site investigation, as

discussed in the following section.

3.2.5 Data Requirements: Site Investigation Phase

The following describes the components of work

likely to form the hydrogeological part of a typical

site investigation:

• Digging of trial pits to allow inspection of

shallow, in-situ ground conditions;

• Drilling of boreholes to provide:

1) Lithological details of strata

penetrated, and their distribution

spatially (across the site) and with

depth;

2) Zones of groundwater occurrence as

the borehole is drilled, as an

indicator of depth to water and

permeability;

3) A means of carrying out in-situ

permeability tests using one of the

standard techniques such as falling

or rising head tests.

• Completion of boreholes with standpipes to

provide:

1) A means of measuring groundwater

levels;

2) A facility for water sampling for

chemical analysis.

• Performance of pumping tests to provide

data on permeability, specific yield etc. if

required;

• Longer-term monitoring of groundwater

levels and quality to assess seasonal

change and post-construction monitoring to

validate the completed scheme.




3.2.6 Notes on Site Investigation Techniques

As referred to in section 3.1, this section covers the

following general issues applicable to site

investigation:

• Physical extent of investigation and timing;

• Health, safety and environment Issues;

• Site preparation and existing utilities issues;

• Techniques of intrusive investigation

including:

1) Trial Pits;

2) Light Cable Percussion Boring;

3) Mechanical Augers;

4) Rotary Drilling, including use of

circulation fluids;

5) Types of probing and penetration

testing.

• Use of Geophysics;

• Site restoration;

• Sampling protocols (soil and groundwater);

• In-situ testing (including permeability tests

and packer tests)

• Field pumping tests;

• Laboratory testing;

• Reporting.

Additional points to note in respect of investigations

focussed on hydrogeological conditions are as

follows:

• Trial pits offer a particularly useful

opportunity to examine rock lithology in

detail and in a relatively undisturbed state;

aspects such as fracture spacing, degree of

weathering and infill can all be examined at

first hand, but the data are applicable to the

first 3-4m only, this being the standard depth

of a trial pit;

• In the context of the conditions that will

generally be found in Qatar, only rotary

coring will allow lithological properties to be

studied with the rock intact;

• Use of non-biodegradable mud as a

circulation fluid during drilling may seal off

fissures and hence provide misleadingly low

permeability values in subsequent in-situ

testing;

• Air-flush drilling will displace water as well as

drill cuttings and provides a useful guide as

to the groundwater level. This is used to

record the depths at which most water is

produced, with the most permeable zones

being below the water table;

• Standpipes slotted over the full length of the

hole may provide an artificial connection to

permeable layers otherwise separated by

impermeable ones, thus confusing hydraulic

relationships and providing mixed-water

samples. If a lack of vertical hydraulic

continuity is suspected, casagrande-type

piezometers may be considered. Standpipes

with restricted open areas (i.e. with the

annular space above and below the

response zone sealed with an impermeable

grout) may also be considered;

• Whilst tests on individual boreholes will

provide values of permeability, either depth-

related or bulk for the whole depth of the

borehole, the most comprehensive testing

regime for obtaining aquifer parameters over

substantial parts of the site is through a

pumping test, the main components of which

are:

1) Installation of a pumping well from

which groundwater can be

abstracted at a constant rate,

continuously for one - two weeks

minimum;

2) A means of measuring the discharge

from the pumping well and the taking

of water level measurements within it

in response to pumping;

3) A means of conveying the pumped

water away from the test site so that

it does not re-circulate;

4) Installation of one or more

observation wells from which water

level measurements can be taken in

response to pumping;




5) The taking of water level

measurements for at least seven

days before pumping begins in order

to identify any background effects;

6) The taking of water level

measurements after pumping stops

in order to obtain recovery data for

further analysis;

7) The taking of water samples at

intervals to check for changes in

quality as the cone of depression in

the water table expands in response

to pumping;

8) Analysis of the data using graphical

techniques or computer models but

in all cases using methods whose

inherent assumptions approximate to

the field conditions (e.g. for

unconfined conditions).

• When planning pumping tests (or dewatering

schemes) in areas where there are adjacent

properties it must be recognised that the

cone of depression may extend beyond the

site boundaries, leading to the possibility of

settlement beneath adjacent buildings.

Monitoring of settlement is mandatory under

such circumstances;

• With respect to the taking of water levels

under any circumstances, the following may

be noted:

1) It may be most cost effective to

monitor groundwater levels

automatically using data-loggers that

can be either manually downloaded

or be configured to automatically

transmit the data to a designated

source;

2) Basic data should include the survey

of the measuring benchmark (e.g.

the top of the borehole casing) to

QNHD so that the water levels can

be plotted as absolute levels;

3) Groundwater levels in boreholes or

piezometers should not be regarded

as representative of in-situ

conditions unless they are taken at

least 24 hours after completion of

drilling.

• Regarding water quality, a more detailed

understanding of the hydrochemical

conditions may be required. In these cases,

sampling protocols require rigorous

attention. The following comments apply:

1) The need for wellhead (field)

determination of parameters such as

temperature, pH, electrical

conductivity, dissolved oxygen and

redox potential (Eh) should be

considered, including use of a flow-

cell;

2) Samples should be obtained in clean

containers, preferably supplied by

the laboratory responsible for the

chemical analysis;

3) Samples should be stored in a cool

place away from sunlight, and should

be taken to the laboratory as soon as

possible, preferably on the day that

they are taken;

4) The analytical suite should include

all major anions and cations but at

least sodium, potassium, calcium,

magnesium, sulphate, chloride,

carbonate/bicarbonate and nitrate,

so that an ionic balance can be

carried out as a check on the

accuracy of the analyses;

5) Other parameters may require

determination to suit the

requirements of particular

investigations;

6) The laboratory should as far as

possible, be independently

accredited for the testing carried out.

3.3 Surveys

Early collection of accurate survey data is crucial to

the success of all design projects, but is frequently

also necessary during planning stages in order to

assess the viability of different options.




The nature of the work in hand will determine the

type of survey work required. Almost all new

pipeline installations will require at least some

topographical work, but other types of survey are

also frequently necessary.

This should be considered in the early stages of

project programming, so that appropriate contractors

with the necessary expertise can be sourced and

mobilised. Some of the less common survey

expertise may only be available outside Qatar and

can take six or more months from first inquiry to

mobilisation to Qatar.

3.3.1 Types of Survey

Types of survey required may include:

Conventional Topographic Using Total Station or

Manual Instruments

Conventional topographic surveys will be

appropriate for most smaller scale projects and the

designer should consider carefully the information

requirements for the success of the project.

It is not appropriate to write a general specification

covering all projects because they all differ.

However, the general guidelines below should be

followed.

1) All levels should be reported in metres

above QND.

2) For most hard ground, levels in millimetres

can be rounded to 2 decimal places e.g.

6.01m. If extreme accuracy is required, this

should be noted specifically. In open

unmade ground, levels to 1 decimal place

e.g. 6.1m will be sufficient.

3) For design purposes, proposed levels

should be quoted to three decimal places.

4) Co-ordinates should always be tied in with

QND.

5) Survey data should be provided in digital

and hard copy.

6) Digital survey data should be presented in

AutoCAD files at 1:1 scale

7) Paper copies should be at 1:100, 1:500,

1:1250 or 1:2500. Other scales are not

acceptable.

8) Survey grid sizes should be carefully chosen

to the suit the needs of the project. For a

new treated urban area, a grid of spots at

5m x 5m may be sufficient.

9) For laying of pipelines over long distance

spot levels at 50m intervals should be

sufficient in flatter areas, reducing to 10m on

inclines.

10) For a pipeline route, the width of study

corridor surveyed may be as much as 50m

wide to each alternative route at planning

stage. This may reduce to 10m wide where a

final route has been chosen and levels are

required for detailed design. It is important to

give sufficient coverage at planning stage,

as the results of other surveys (such as

geotechnical) will frequently have an impact

on choice of route, resulting in the need for

changes and more survey information at

later stages.

For pipelines laid by trenchless techniques

the only points of real interest are at the

beginning and end points. If ground levels

do not vary significantly in between, they are

of no interest. The location of topographical

features may, however, be important in

relation to other considerations, such as

property boundaries and legal notices.

All surveys should pick up relevant

topographical features in the vicinity of the

study area, such as ground types, manholes,

kerblines, boundaries, fences and barriers,

overhead cables, wadis, trees, buildings and

all other obstructions.

The surveyor should be instructed to

maintain effective checking systems at all

stages of the production of the survey. The

object should be to ensure accurate work

and/or detect errors and omissions before

the issue of the final survey record. The

surveyor should record the locations and

value of all survey stations used during the

survey.

Aerial Photogrammetry




Aerial Photogrammetry is commonly used for

planning major developments in inaccessible areas.

It may be of use for planning routes of long

transmission pipelines; however, its use is now

becoming superseded by satellite imagery.

Satellite Imagery

Satellite Images have now been prepared for most

developed parts of the world. Although originally

developed for military purposes, these can now be

obtained commercially. Again, they can be of use

during the planning stages of a project.

GPS Surveys

GPS Surveys also use satellite information.

Handheld GPS units are very useful for quick

determination of co-ordinates in relation to the

National Grid, but collection of accurate data

requires more sophisticated equipment. Current

mobile models, carried in backpacks should be

capable of providing co-ordinate and levels to sub-

metre accuracy. Quoted accuracy is typically ±

005m horizontal and ±0.01m vertical. These units

provide an excellent method of obtaining data

quickly in remote locations.

Manhole Location (Confined Space) Surveys

Manhole Location Surveys will be necessary when

compiling computer models of existing sewers and

when tying new works into existing. These must be

carried out by specialist contractors with appropriate

experience. The work involves entry into confined

spaces, and often requires traffic management.

Survey contracts should be carried out in

accordance with the requirements of WRC/WSA

Model contract2, adapted for use in Qatar.

Impermeable Area Surveys

Impermeable Area Surveys are sometimes

necessary for the design of new drainage in existing

2 The UK Water Industry Engineering and

Operations Committee. 2003. Model Contract for

Manhole Location Surveys and The Production of

Record Maps. 2nd ed. Marlow, Buckinghamshire:

Water Research Centre (WRc) Publications.

urbanised areas. The ultimate aim is to provide an

accurate estimate of the percentage impermeable

areas of all of the subcatchments in order to

determine more accurate times of concentration and

critical storm durations. Such surveys are generally

carried out during the process of information

collection and should be carried out by an

experienced engineer or technician. The procedure

involves a systematic visual survey of the whole

catchment on foot, marking up all of the paved areas

onto a topographical survey map of appropriate

scale. Ground types should be noted, and colour

coded. It is not generally practical to measure

accurately all of the contributing areas, but the areas

marked up on the survey drawing can be measured

in the office with the use of a planimeter

House Connection Surveys

House Connection Surveys may also be necessary

for design of foul sewers to service existing

catchments. Again, there is no set procedure for

this, but it involves a systematic investigation of all

the properties in the catchment to determine

whether they are already connected to the system,

or served by septic tank or other means. Data

should be reported on a proforma, the format of

which will be determined by the DA in the PSA. This

form will be different for each project. An example

of such a form is included in Appendix 1. Each

property will need to be visited, and information to

be determined will, as a minimum, include:

1) Type of property and number of inhabitants.

2) Water and Electricity Department Numbers.

3) Co-ordinates, size, materials and level of

septic tanks.

4) Terminal manhole information, co-ordinates,

cover level and depth.

5) Connection pipe diameter, length and

material.

6) Buried utility locations.

Buried Utilities Location

The normal procedure for location of buried services

should initially follow the guidelines laid out in

Section 2.3. It is conceivable that information

received by this method may need to be

supplemented by site surveys. These will normally




include a variety of methods, such as trial pits to

confirm locations, use of probes to confirm pipe

routes between manholes, ground radar to locate all

non-metallic pipes, and pipe tracing using hand held

electrolocation detectors (not suitable for plastic

pipes).

CCTV Surveys

CCTV Surveys are necessary for assessing the

condition of existing sewers. Work should be carried

out in accordance with the WRC Model Contract3,

and results reported according to the WRC Manual4.

Flow Surveys

Flow Surveys are sometimes necessary for

confirmation of sewer flows for the purpose of sewer

modelling and design. They should be carried out in

accordance with the Model Contract for Short Term

Flow Surveysi.

Again, this could be adapted for conditions in Qatar

and careful consideration given to timing in relation

to local weather patterns.

Bathymetric and Drogue Surveys

Bathymetric and Drogue Surveys (current

monitoring) will be necessary for the design of

coastal outfalls. Also specialist in nature, the survey

requirements will be dependent upon the modelling

software to be used.

Structural Condition Surveys

Structural Surveys should be recommended for

existing structures adjacent to tunnelling or other

deep excavations. These will generally include a

3 Water Research Centre (WRc). 1990. Model

Contract for Non Man-Entry Sewer Inspection. 3rd

ed. Marlow, Buckinghamshire: Water Research

Centre (WRc) Publications.

4 Water Research Centre (WRc). 1993. Manual of

Sewer Classification. 3rd ed. Marlow,

Buckinghamshire: Water Research Centre (WRc)

Publications.

pre-condition survey, and monitoring of any existing

cracks during construction.

3.4 Operating Data

Operating data is available or can be

measured/obtained for the existing DA facilities as

outlined in the following sub-sections.

3.4.1 Pumping Stations

Fixed Data

• Pump type/manufacturer;

• Pump numbers and configuration;

• Pump duty/operating arrangements;

• Wet-well capacity;

• Pump on/off/alarm levels;

• Rising main diameter, length and material;

• MCC manufacturer;

• Pump control sensors;

• Flow measurement facilities;

• Inflow screening equipment;

• Surge protection measures;

• SCADA/Telemetry facilities.

Variable Data

• Levels in wet well (e.g. low, high water and

alarm levels);

• Pump running details (hours run and start

stop times);

• Flow meter records.

Test data

• Actual pump flow Q and head losses H in

rising main (i.e. actual H/Q diagram);

• Pump efficiency, energy use and other

relevant performance data.

• Data from drop tests




3.4.2 Sewage Treatment

Fixed Data

Sewage treatment plants contain extensive

electromechanical, civil and instrumentation

facilities. As required for a project, these can be

surveyed and reported on so as to define the actual

details of the plant.

Variable Data

Numerous data can be recorded at a sewage

treatment plant such as:

• Operating levels in tanks, chambers etc.;

• Operating details of electromechanical

equipment;

• Flows through the various elements of the

plant.

Test Data

• Extensive testing can be done on the

sewage, effluent, and sludge at the various

stages in the process to determine the

physical, chemical and biological properties;

• Other data arising from the operation of the

plant such as odour and noise;

• Testing of electromechanical plant to

determine actual operating performance

characteristics can also be undertaken.

3.4.3 Sewerage

Operating data for sewerage networks would be

limited to:

• Flow logging;

• Physical inspection: man entry for manholes

and CCTV of pipelines to check for

blockages, pipe damage, and other aspects

that might affect the flow characteristics of

the system.

3.4.4 Surface Water/Hydrology

Operating data for drainage networks would be

limited to:

• Flow logging;

• Physical inspection: man entry for manholes

and CCTV of pipelines to check for

blockages, pipe damage, and other aspects

that might affect the flow characteristics of

the system;

• Measurement of rainfall, especially if it can

be combined with flow logging, provides very

useful information;

• Groundwater monitoring can also be

undertaken.

The data listed in the above sub-sections can be

obtained by various means.

• Existing data record by the DA. The

Department’s central SCADA control is

continually expanding its capability and

extensive information on sewerage network

pumping facilities is available;

• The DA can award specific data collection

contracts;

• Data collection requirements can be

incorporated into design PSAs.

3.5 Asset Condition

Asset condition can be determined by two methods:

• Review of existing reports and studies;

• Actual surveys of the assets.

The process of undertaking surveys is described in

Section 3.3 of this volume. Where existing reports

and studies exist, these can be obtained from the

DA.

3.6 Meteorology

3.6.1 Introduction

Section 3.6 provides an overview of the climate and

meteorological conditions in Qatar. It includes

sufficient information for Designers to gauge the

degree of weather severity in the State in relation to

sewerage and drainage design, and provides

maximum values for design purposes.




3.6.2 Climate Overview

This overview of the climate in Qatar has been

developed from a number of sources including the

‘Long Term Climate Report – 2000’ (LTCR)ii,

together with information from relevant journal

articles detailing specifics of Qatar’s climateiii. The

LTCR is based on data recorded at Doha

International Airport (Latitude 25 15’N and Longitude

51 34’E) between 1962 and 2000.

The State of Qatar occupies a peninsula situated on

the eastern coast of the Arabian Gulf, covering an

area of 11 437km2. Qatar also comprises a number

of offshore islands. The topography of mainland

Qatar is generally flat and low-lying except for a

slight rise in the Dukhan area in the west. Almost

the whole area of the State of Qatar is a desert, with

very similar climatic conditions throughout the Arab

State. The climatic regime of the area is classed as

arid. Essentially, this means that the potential water

loss by evaporation and transpiration exceeds the

amount of water supplied by precipitationiii.

The climate throughout the year in Qatar is closely

related to climatic conditions in other Gulf States

such as Bahrain, Kuwait and Sharjah in the United

Arab Emirates (UAE). The climate is typically

represented by high humidity throughout the year

except when hot, dry winds blow from the mainland.

Annual rainfall is very low and falls mainly between

the months of December and April.

The weather in Qatar over the summer months is

dominated by semi-permanent heat low-lying over

the Arabian Gulf. Cloud formation is inhibited by the

sub-tropical anticyclonic cell situated above the low

pressure areas on the surface. Temperatures

between June and September are extremely hot,

with maximum temperatures reaching close to 500C.

Rainfall in the summer months is very infrequent

and, when it occurs, in very low quantities

For the rest of the year, the weather is greatly

influenced by the mid-latitude frontal systems.

These systems mostly originate over the

Mediterranean Sea and can give rise to

precipitation, sometimes in the form of

thunderstorms.

The peninsula of Qatar is also subject to a land-sea

breeze effect, caused by the quick radiation cooling

of the land as compared to the sea during the night.

The following sections outline key climatic features

of Qatar and provide an analysis of existing data. It

should be noted that climate characteristics are

determined from a single climate station located in

Doha, with available and sufficient data. Therefore,

the DA deems that it is reasonable to make the

assumption that the climatic data collected in Doha

is representative of the entire State of Qatar.

3.6.3 Rainfall

An important climatic feature for sewerage and

drainage design is rainfall. The average annual

rainfall in Qatar is low at around 82.8mmiii. Rain

mainly falls during the months of December to April,

with February and March accounting for almost half

of the annual total. In comparison, rain in Qatar is

commonly absent in the summer months between

June to September. Thunderstorms occur mainly in

March and April.

In line with other arid regions of the world, inter-

annual variations in rainfall are very large in Qatar.

The highest annual total on record is 302.8mm in

1964. Over half of this fell in December to give the

highest ever recorded monthly total. However, in

1962, the annual rainfall was just 0.4mm, the lowest

on record. This effectively classifies Qatar as lying in

an ‘extremely arid area’ which, according to one

definition, is an area where precipitation totally lacks

any rhythm and remains at zero for at least twelve

consecutive monthsiii.

Average and extreme rainfall values in Qatar are

summarised in Table 3.6.1, below.

Table 3.6.1 –Summary of Qatar Rainfall

Characteristics (1962-2000)

Rainfall Characteristics Value (mm)

Annual Average 83

Highest Annual Rainfall 302.8

Lowest Annual Rainfall 0.4

At the time of compilation of this Manual, 39 years of

comprehensive rainfall data from 1962-2000 was

available from a single rain gauge at Doha

International Airport. The rain gauge is operated by

the Department of Civil Aviation and Meteorology, of




the Ministry of Communication and Transport, and

provides the largest record in Qatar.

The Department of Civil Aviation and Meteorology

processes the daily rainfall data from this rain gauge

and produces climate reports which contain a

summary of annual rainfall depth, maximum rainfall

in 24-hours and the number of rainfall days in a

year.

Table 3.6.2, below, provides a comparison of the

average and peak monthly rainfall values over the

period of 1962-2000. Peak monthly rainfall is

defined as the highest rainfall value recorded for

each respective month over the entire rainfall data

period.

The monthly maximum rainfall in 24-hours and the

mean number of rainfall days over the 39-year

record are provided in Table 3.6.2 below.

Table 3.6.2 - Average and peak monthly rainfall

in Qatar taken at Doha Airport (1962-2000)

Month Average Monthly

Rainfall (mm)

Peak Monthly

Rainfall (mm)

Jan 13.9 101.8

Feb 17.5 130.5

Mar 21.4 141.6

Apr 7.4 68.1

May 3.1 106.4

Jun 0.0 0.0

July 0.0 Tr

Aug 0.0 0.7

Sep 0.0 Tr

Oct 1.1 17.3

Nov 5.6 110.5

Dec 12.8 115.4

Note: Tr- indicates a trace amount of rainfall. Source:

LTCR, (2000).

Table 3.6.3, summarises statistical parameters for

existing rainfall data, including mean, maximum and

minimum values for annual rainfall, maximum rainfall

in 24-hours and number of rainfall days for the 39-

year record.

A comparison of maximum and minimum values in

Table 3.6.4 indicates a large variation in rainfall. In

addition, the coefficient of variation for rainfall depth,

which is defined as the ratio of the standard

deviation and the mean, was found to be 0.85. This

value is high in comparison to well-watered regions

where coefficients are as low as 0.1iii.

From 1978, a second climatological station was

installed at the Doha Port, approximately 4km from

the station at Doha International Airport. Table 3.6.5

outlines the variation in rainfall characteristics in

Qatar through a comparison of data at Doha Port

Station and Doha International Stationvii. The

correlation of the annual rainfall depth and the

number of rainfall days is high as compared to the

maximum rainfall in 24-hours.

Table 3.6.3 - Maximum Rainfall in 24 Hours and

Mean Number of Days with Rainfall 1mm or

More. (1962-2000), taken at Doha Airport

Month

Maximum Rainfall in 24hrs & Year of

Occurrence

Mean No. of Days with

Rainfall 1mm or More

Jan 58.0 1969 1.8

Feb 44.6 1993 2.0

Mar 58.2 1995 2.2

Apr 34.4 1976 1.3

May 64 1963 0.2

Jun 0.0 - 0.0

July 0.0 - 0.0

Aug 0.7 1983 0.0

Sep 0.0 - 0.0

Oct 17.3 1977 0.1

Nov 45 1976 0.5

Dec 80.1 1964 1.3




Table 3.6.4 - Summary of Statistical Parameters for Rainfall Data (1962-2000) taken at Doha Airport

Variable Mean Maximum & Year

Minimum & Year

Standard Deviation

Coefficient of Variation

Total Annual Rainfall (mm) 82.8 302.8 1964 0.4 1962 70.0 0.85

Maximum Rainfall in 24 hrs (mm) 26.4 80.1 1964 0.2 1962 18.6 0.70

No of Rainfall Days per year in excess of 1mm 9.4 22 1964 0 1962 5.8 0.62

Table 3.6.5 - Variation of Rainfall Characteristics in Qatar- Doha Port and Doha International Airport (for Data between 1979-1989)

Year

Annual Rainfall Depth

(mm)

Max Rainfall in 24 hrs

(mm)

No. of Rainfall Days

>1mm

D.I.A D.P D.I.A D.P D.I.A D.P

1979 101.9 107.4 48.8 34.3 7 9

1980 50.8 71.4 20.2 25.1 10 15

1981 33.8 31.1 12.7 12.1 6 6

1982 167.3 130.3 40.1 44.6 20 17

1983 68.1 59.8 17.5 24.1 8 8

1984 40.9 45.9 16.2 13.1 4 5

1985 9.7 11.4 3.8 8.6 3 2

1986 78.0 72.2 17.1 17.9 12 12

1987 61.3 65.9 28.0 37.5 4 2

1988 152.8 170.1 41.3 39.8 12 14

1989 69.7 129.7 34.9 104.0 11 11

Mean 75.85 81.38 25.51 32.83 8.82 9.18

Correlation

Coefficient

0.880 0.591 0.908

Note: D.I.A =Doha International Airport Station; D.P= Doha Port Station. Source: Bazaraa & Ahmed (1991) and LTCR (2000).




3.6.4 Other Climatological Variables

A summary of other key climate characteristics in

Qatar is provided in Tables 3.6.6–3.6.8. The

following sections provide an overview of some of

these characteristics, including surface air

temperature, wind speed and direction, and relative

humidity. Climate data was collated from only one

station (Doha International Airport), as there is

insufficient climate data elsewhere in Qatar.

Therefore, in the absence of data to indicate

otherwise, it is recommended that the climate details

presented in this Manual are used for all other

locations in the State of Qatar, unless site specific

data becomes available (for example, through a

dedicated monitoring programme of specific climate

variables).

3.6.5 Wind Speed and Direction

Surface Air Temperature

As mentioned in previous sections, the climate in

Qatar consists of extremely hot and humid summers

and mild winters. The summer months are from

June to September, whilst the winter months run

from December to February.

The maximum surface temperature ever reached in

Qatar was recorded on 9 July 2000 at 49.60C, whilst

the minimum was 3.80C, recorded on 21 January,

1964.

In general, the highest temperatures occur in the

mid-summer month of July, with a mean monthly

temperature of 34.90C.

As summarised in the LTCR (2000)ii, the surface

wind flow over Qatar is influenced by different

pressure systems. In winter and transition months,

the mid-latitude frontal systems dominate the wind

regime, whereas in summer months the wind regime

is primarily influenced by thermal lows over the

Indian subcontinent and Sudan (extending to Saudi

Arabia and Qatar). Concurrently, the direction and

speed of surface winds in Qatar is also influenced

by the Zagros Mountains of Iran, and the highlands

of the Arabian Peninsula.

Wind characteristics recorded at Doha International

Airport during the period 1974-2000 are summarised

in Table 3.6.6.

Relative Humidity

Typically, the months of May and June have the

lowest relative humidity with an average value of

43%, but mostly within the range of 40-50%. In

comparison, the humidity gradually increases

towards the winter months to about 70% in the

months of December- February.

In addition to the variables examined, Table 3.6.7

and Table 3.6.8, below, provide peak and average

monthly values for Atmospheric Pressure and

Vapour Pressure, Fog Days, Sunshine Hours,

Global Solar Radiation and Evaporation (Pan).




Table 3.6.6 - Summary of Wind Characteristics in Qatar

Wind Characteristic Units Value

Predominant wind direction - Northwest

Highest wind speed (10 min duration) Knots 40

Highest wind speed (1 Hr duration) Knots 36

Highest wind speed reported (gust) Knots 54 (achieved March 1995)

Mean wind speed from December to January Knots 8.9-9.3

Mean wind speed from February to May Knots 7.8-8.2




Table 3.6.7 - Summary of Climatological Characteristics in Qatar

Month

Air Temperature ( C) Fog Atmospheric Pressure (hPa)

Vapour Pressure (hPa)

Relative Humidity (%)

Peak Monthly

Average Monthly

No of Days with visibility

<1000 m

MSL Average Monthly

Average Monthly

Peak Monthly

Average Monthly

Jan 21.9 17.2 3.4 1019.1 14.0 88 71

Feb 23.1 18.1 2.6 1017.1 14.4 87 70

March 26.7 21.2 1.0 1014.3 15.5 84 63

April 32.1 25.9 0.3 1010.9 17.2 75 53

May 38.3 31.2 0.4 1006.7 19.1 66 43

Jun 41.3 34 0.6 1000.6 21.4 67 43

Jul 41.6 34.9 0.7 997.6 26.2 73 49

Aug 40.8 34.5 0.6 999.5 29.9 78 56

Sep 38.7 32.4 1.6 1005.4 29.4 83 62

Oct 35.2 29.1 2.2 1012.2 25.0 83 63

Nov 29.5 24.3 1.4 1016.7 20.0 84 66

Dec 24.3 19.4 3.1 1019.0 16.3 88 71

Yrs. of

Data

39 39 39 27 27 27 27

Years 1962-2000 1962-2000 1962-2000 1974-2000 1974-2000 1974-2000 1974-2000




Table 3.6.8 - Summary of Climatological Characteristics in Qatar

Month

Wind Sunshine Hours

Global Solar Radiation (mWh/cm2)

Evaporation Pan (mm/day)

Average Speed (kt)

Speed (Kt) based on 10 mins

Direction (degrees) based

on 10 mins

Average Daily

Peak Daily

Average Daily

Peak Monthly

Average Daily

Jan 8.2 28 330 7.9 502.4 374.9 11.56 3.91

Feb 8.9 30 350 8.2 663.1 436.6 11.17 5.00

March 9.3 40 340 7.9 757.8 489.3 14.87 6.69

April 8.9 33 360 9.2 781.9 569.9 20.25 9.73

May 9.3 38 340 10.6 777.1 620.4 28.50 13.42

Jun 10 38 330 11.6 799.5 646.3 30.60 15.60

Jul 8.4 30 340 10.6 802.7 605.1 27.79 13.61

Aug 8.1 33 330 10.7 718.2 584.7 32.02 11.80

Sep 6.7 30 350 10.2 697.6 545.8 21.20 9.44

Oct 6.9 30 350 9.9 673.2 481.7 18.78 7.64

Nov 7.6 40 350 9.1 560.6 414.9 14.40 5.51

Dec 7.8 28 350 7.9 455.2 349.8 10.58 3.83

Yrs. of

Data

27 26 26 26 18 18 25 25

Years 1974-2000 1975-2000 1975-2000 1795-2000 1976-

1993

1976-1993 1976-2000 1976-2000

Source: LTCR, (2000).




3.7 Environmental Investigations

3.7.1 Introduction

This section provides general guidance on the

various types of environmental investigations

required for sewerage and drainage projects.

3.7.2 Strategic Environmental Assessment (SEA)

The following items require environmental

investigation during the planning process:

• The current and evolving features of the

State of Qatar National Physical

Development Plan;

• Associated population growth trends,

expectations and projections for various time

horizons;

• Land use plans associated with national and

local physical development plans;

• National conservation areas and the

identification of protected ecological areas;

• Internal investigations should be made

relating to DA Environmental Policy – e.g.

final effluent standard targets may be more

onerous than those applicable under

SCENR Environmental Protection

Standardsvi;

• DA Environmental Management Plan

(ISO14001) – e.g. has an environmental

audit been undertaken across the sewerage

and drainage sector, or a particular works,

and what were the findings?;

• DA Monitoring Programme – laboratory

quality accreditation, sampling location,

frequency, criteria analysed, results,

database storage, equipment used, staff

training for monitoring, response to

unacceptable data, as well as any other

outstanding issues.

3.7.3 EIA Investigations

A EIA might include the following types of

investigations:

Walk Over Surveys

These are a qualitative overview of the site,

surrounds, and potential issues meriting more

detailed investigation.

These surveys should provide general baseline

information and allow the assessor to have a

general appreciation of the site and surrounding

area. From this survey, the most significant impacts

may be defined. Impact interactions, secondary

impacts and cumulative effects would also be

identified through this procedure.

Ecological (Flora and Fauna) Surveys

An initial ecological site survey should provide a

description of the baseline environment in terms of

habitats and species present. This would identify the

potential need for further surveys to be conducted

should the presence of statutorily protected species

or habitat be identified. Ecological Surveys should

be conducted by an appropriately qualified ecologist.

Baseline Noise Levels and Predictions

The site survey should provide baseline information

on ambient noise levels in order to ensure

compliance with Qatari Environmental Regulations.

Following the survey, the data should be

manipulated and run through various models to

determine projected noise levels during both

construction and operation following the

development of the works.

Baseline Odour Level and Predictions

Guidance on investigations required for odour

assessment is included in Volume 5, Section 1.5.

Baseline Air Quality and Predictions

The site survey should provide baseline information

on ambient air quality levels in order to ensure

compliance with Qatari Environmental Regulations.




Incoming Effluent Quantity and Quality Sampling

Specific requirements and suggested methodologies

are detailed in Volume 5, section 1.15.

Existing Wastewater Quantity and Quality

Sampling

Specific requirements and suggested methodologies

are detailed in Volume 5, section 1.15.

The breadth and depth of detail required for these

investigations should be agreed in advance with the

DA, and in consultation with SCENR. Typical

outline investigation methods and data collection

requirements are included for certain types of

activities in Volume 3, Section 3.2, Volume 4,

Section 1.5, and Volume 5, Section 1.5).

Water quality, noise and odour surveys are

particularly important for the EIA process. More

detailed guidance on water quality and odour

surveys are presented in Volume 1, Section 3.4, and

Volume 5, Section 1.5, respectively.

The surveys and their subsequent assessments aim

to ensure that both existing and future potential

receptors will not be significantly adversely impacted

as a result of any construction works or operation.

Results from the surveys should be tested against

pre-determined criteria defined and agreed through

consultation with SCENR.

Existing and future potential receptors include

operations and maintenance staff, nearby residential

properties and inhabitants of any future proposed

housing in the vicinity. All parameters should be

tested for compliance to the relevant Qatari

Environmental Standards. If the case arises where

it is deemed that there would be a significant

adverse impact, appropriate mitigation measures

should be assessed in order to reduce or eliminate

the potential adverse effect.




4 Design Process

4.1 Background Information

4.1.1 Existing Services and Utilities

On commencement of a design project, the parties

listed in the Foreword, Section ii, of this Volume.

should be contacted to request any service

information relevant to the design project. These

requests are hereafter referred to as design

enquires. All requests must be accompanied by a

letter of authorisation from the DA, indicating

consent for the consultant to collect information on

the behalf of the DA. Example letters are included in

Appendix 7.

When information is not forthcoming, the consultant

is to pursue this matter with the concerned authority

and notify the DA. In the event that receipt of

information is unduly delayed or not received, the

consultant must advise the DA of any delays to the

project or design assumptions made in it’s absence.

4.1.2 Services Hierarchy

Service reservations are shown on standard Drg.

No. SR 1 and SR 2 in Vol. 8 of this manual. Service

reservation corridor widths of 16, 20, 24, 32, 40 and

64m are possible, and consistent with the Qatar

Highway Design Manual, with the exception of the

surface water reservations, which are not shown.

Service reservations for surface water are not

included in the Qatar Highway Design Manual.

Consultants must therefore consult with DA on each

project to confirm surface water corridors.

The standard service corridor sections are not

applicable at junctions and interchanges. In such

cases, the general guidelines listed in the following

sub-sections are to be followed.

Roundabouts

Drainage works should extend into the roundabout

with the intersection point in-line with the corridors

on either side, as there is usually sufficient space

within the roundabout to accommodate the

necessary manholes and chambers. If obstacles

within the roundabout prevent this, the services

should be located within the road close to service

reservations, but the number of direction changes

should be minimised.

Split Level Interchanges

Underpasses effectively provide a barrier to services

therefore they must be diverted. Such diversions

must be undertaken even when such schemes are

only at master planning stage and the consultant is

to liase with the Roads Affairs to ensure sufficient

provision is made.

Major Junctions

These will usually be signalised, with road layouts to

suit the necessary turning and holding lanes.

Provision must be made within the drainage design

works for the specific layout and this is to be done in

co-ordination with, and to the approval of, the Roads

Affairs.

Non-perpendicular Junctions

In order to avoid changes in direction of flow

exceeding 90o pipes may have to locate outside of

the designated corridors. In this event, permission

must be obtained from any service authority

affected.

Existing Services

Existing services may not be within the designated

corridors, resulting in a change to standard

hierarchy. In this event, the changes are to be

carried out in co-ordination with the authorities

concerned, and with their full approval.

4.1.3 Site Investigations

Investigations of the types detailed in section 3 will

be undertaken as per the specific requirements of

the project brief. The scope of the investigation must

be finalised by the consultant and approved by the

DA prior to work commencing.

In determining the scope of the investigations, the

consultant is to formally ask the DA for any reports

from previous investigations to avoid any

unnecessary works. The consultant is to also

prepare a schedule of other organisations that may

have carried out relevant investigations and make

appropriate requests on behalf of the DA and update




the schedule to show responses received. The DA

are to be advised of updates to the schedule.

A statement from the consultant confirming that all

enquires have been undertaken and due cognisance

taken of previous investigations is required when the

proposal for the scope of the investigations is

proposed.

4.1.4 GIS / AIS

The DA has it’s own GIS section that handles the

input and abstraction of information that relates to

the DA’s assets. This is linked to the Ministry’s main

Centre for GIS (cGIS). Requests can be made

through the CSD for information on DA existing and

proposed assets. Information on plot boundaries,

roads layout, and any other information on the cGIS

network can also be reproduced. It is, however, the

consultants’ responsibility to confirm the accuracy of

such data.

Design information produced by the consultant is to

be in a format that is compatible with the GIS.

Adherence to Vol. 7 - CAD Manual, will ensure this.

4.1.5 QNBS/QCS

The basic specification for DA works is the Qatar

National Building Specification (QNBS) published by

the Ministry of Public Works. This is comprised of

the following sections:

• 1 – General

• 2 – Demolitions and Alterations

• 3 – Excavations and Earthworks

• 5 – Concrete Work

• 6 – Blockwork

• 7 – Roofing

• 8 – Carpentry, Joinery and Ironmongery

• 9 – Structural Steelwork

• 10 – Miscellaneous Metalwork

• 14 – Finishes

• 15 – Glazing

• 16 – Painting and Decorating

• 19 – Roadworks

• 20 - Drainage

The QNBS has been the subject of numerous

variations and these are to be included in tender

documentation. The tender document is also to

contain a further specification (Clause 21) that will

contain any project-specific clauses and variations

required to the QNBS for the particular project.

The Qatar Construction Specification (QCS) is a

more recent document in use by other departments,

but it is still undergoing revision with supplementary

clauses for DA projects. Until such time as these are

complete, it should not be used on DA projects.

4.2 Ground Conditions

An understanding of the geology is fundamental to

interpretation of hydrogeological conditions. This

Section presents a review of the geological

conditions that characterise the State of Qatar,

followed by a description of the hydrogeology. In

both aspects there is a focus on the upper parts of

the sequence because it is the shallower zone that

is most relevant to drainage projects.

The general objective of this section is to provide a

guide to the general conditions that are likely to be

encountered. However because of variability, there

is always a need for site-specific information and the

review presented here is intended as a basis for the

additional investigations described in section 3.2.

4.2.1 Topography & Regional Geology

Qatar is a peninsula of low-moderate relief, the

highest elevation being 103mQND in the south.

There is a gentle slope towards the sea from inland

areas.

A significant landscape feature is the series of

shallow depressions that are caused by dissolution

of gypsiferous and calcareous strata at depth,

resulting in collapse at the surface. Some 850 such

features have been identified, ranging in size from a

few hundred metres to 3km in diameter. The

resulting occurrence of low-lying areas is of

particular significance in drainage projects.




The regional geological sequence is summarised in

Table 4.2.1 below.

The modern-day topography and surface geology

was created largely as a result of post-Eocene

tectonic and geomorphic activity. Following

deposition of the Dammam Formation, widespread

emergence of the landmass from the sea occurred,

accompanied by considerable erosion.

Submergence and the re-establishment of marine

conditions then occurred again, leading to

deposition of the Dam Formation. The Qatar

peninsula finally emerged at the end of the Miocene

at which time the Hofuf gravels were laid down. In

the Quaternary period beach deposits accumulated

and with the onset of arid conditions, dunes and

sabkha deposits formed.

At the present time, some 80% of the land surface of

the Qatar peninsular is formed by the Dammam

Formation. The geology of the Dammam Formation

is described in more detail later in this chapter.




Table 4.2.1 - Regional Geological Succession of Qatar

Age Formation

Name

Thickness

Range (m) Formation Description

Pleistocene-

Holocene 0-20

Made Ground (including reclaimed land), residual soils, dunes,

beach deposits and sabkha.

Miocene

Hofuf

Dam

0-10

0-30

Residual gravels

Marls, chalk and limestone

Eocene

Dammam

Rus

0-75

10-120

Chalky and dolomitic limestones, marls and shales

Chalky limestone, anhydrite, marls and shale

Palaeocene Umm er

Rhaduma 270-370

Limestone and dolomites with siliceous and marly zones;

basal shales

Upper

Cretaceous Aruma Dolomites and shales




Certain structural features are apparent that have

had a strong influence on the depositional

environments that created the Rus sequence. The

sedimentary rock sequence beneath Qatar has been

subject to folding, with the present peninsular

located in a zone that has been active since early

Tertiary times. North - South trending anticlinal

(positive) and synclinal (negative) structural areas

can be recognised, with clayey, gypsiferous

(sulphate-rich), sediments deposited in the deeper

marine environments created by the negative areas,

and calcareous dolomitic limestones deposited in

the warmer, shallower, positive structural areas.

As a consequence, calcareous, shallow depositional

rocks characterise the Rus sequence in the northern

and western parts of Qatar and gypsiferous rocks

characterise most of the remainder. This distribution

is more applicable in the upper parts of the Rus

formation than in the lower.

4.2.2 Geology of the Dammam Formation

The geology of the Dammam Formation and the

upper parts of the Rus are summarised in Table

4.2.2 overleaf.

The strata descriptions are summarised from

published reports and from an examination of

borehole logs compiled on an ad-hoc basis by the

DA. It may be noted that consideration is being

given to systematic compilation of such information

on a geological database.

The main features of significance are as follows.

The upper 10–15m of the Dammam Formation, the

Simsima Limestone, is often weathered and altered,

especially where the limestone is fractured and

these are opened up to fissures by solution

processes. Some of the fissures are infilled with

secondary products such as silt, clay, and gypsum.

It may be noted that there are places where the

upper part of the limestone is not fissured and is

more massive. Below 15m the fractures are more

closely spaced and free of weathering.

The lithology of the deeper layers is less well-

recorded in detail. The Midra Shale is reported to

consist of a series of laminated shaley horizons

separated by silty sand. The shales are not

necessarily persistent laterally and the unit may be

fissured. The Rus is reported to be a chalky,

dolomitic limestone.

The weathering of fractures to produce fissures is a

particularly important feature in hydrogeological

terms




Table 4.2.2 - Geology of the Dammam and Upper Rus Formations (characteristic of the Greater Doha area)

Formation Member

Typical

Thickness

(m)

Lithological Description

Recent

Deposits

>1

Residual soils from weathering of the Simsima Limestone below, in

the form of sand and gravel.

Upper

Dammam

Simsima

Limestone 20-30

White or cream coloured microcrystalline or chalky and dolomitic

limestone with secondary siltstone or gypsum in cavities. Fissured

and weathered to a variable extent to10-15m depth from the surface,

becoming fresher with more closely space fracturing at depth.

Lower

Dammam

Alveolina

Limestone 0-1

White, compact, fossiliferous chalky limestone that marks the

boundary between the Upper and Lower Dammam. Not present in

northern Qatar.

Lower

Dammam

Midra

Shale 5-10

Brown, weak, shale interbedded with silty sandstone.

Rus (>10) Interbedded cream and light brown chalky and dolomitic limestone




4.2.3 Hydrogeology

The principal components of the hydrogeological

system are as follows:

• The Simsima Limestone is characterised by

unconfined (water-table) groundwater

conditions, with groundwater stored and

transmitted via fissures that are especially

prevalent in the upper 10–15m;

• The Midra Shale is characterised by low

permeability and is an aquiclude;

• The Rus (and the upper parts of the

underlying Umm er Rhaduma) combine to

form a significant aquifer over many parts of

Qatar.

The Rus and Umm er Rhaduma formations owe

their aquifer designations to enhanced permeability

produced by dissolution. Recharge to the Rus

occurs from infiltrating rainfall in central Qatar, as

evidenced by the presence of a recharge mound,

and groundwater flow is then seawards. As a result,

a freshwater lens has formed that is important over

large areas of Qatar in water resources terms.

In the context of drainage issues, the most

significant attribute of the Rus is that dissolution of

the anhydrite (gypsum) by groundwater movement

within it, has led to collapse of the formations above,

producing depressions at the ground surface.

The permeability within the Dammam Formation is

similarly attributable to dissolution effects, especially

by infiltrating rainfall and resulting groundwater flow.

In the greater Doha area, natural recharge has been

significantly enhanced from sources such as garden

watering, soakaway drainage systems, and leakage

from water mains. Increased runoff as the extent of

paved areas grows, encourages storm water to

pond in the low-lying areas created by collapse of

the Rus, enhancing recharge and standing water at

those locations.

The artificially enhanced recharge has resulted in a

general rise in groundwater levels in the greater

Doha area as it has in many other Arabian Gulf

cities. A network of observation boreholes has

shown a net but variable rise in water table levels in

many areas since 1983. In areas where a sewerage

network has been installed, levels have fallen again.

Rises of 1-2 metres for the period 1983-1991 are

fairly typical.

In Doha there is a general gradient on the water

table in the Simsima Limestone towards the coast

and again, in general, the closer a location is to the

coast the shallower the depth to water table is likely

to be. The water table is typically less than 2.5m

depth within 3km of the West Bay Lagoon area and

typically 2.5 – 5m outside of it. However there are

many local exceptions to this general pattern,

particularly in low lying areas such as Abu Hamour

where standing water persists into the dry season.

It may be noted that where the natural groundwater

condition is high, either district-wide drainage

schemes will need to be installed to achieve the

desired level of at least 4mbgl or, bespoke designs

will be required to dewater the area around

individual building structures. This is particularly

applicable to coastal areas where groundwater

levels are generally the shallowest.

Seasonal variation in groundwater levels is

significant. It is reported that over most of greater

Doha a range of 1-1.5m may be observed as a

seasonal effect, reducing to 0.5-0.6m near the

coast. In low-lying areas, the rise may take

groundwater levels above ground level.

Because of the nature of the permeability in the

Simsima Limestone as secondary due to fissuring, it

is unevenly distributed throughout the formation.

Apart from generally decreasing with depth as

overburden pressure closes up the fractures and the

solution action of water is less prevalent, it also

varies spatially. Thus fissured zones in which bulk

permeability may reach 10-4m/s are interspersed

with zones where it may be 3-4 orders of magnitude

lower.

Both groundwater levels and variations in

permeability have a significant effect on the ability of

chamber-type soakaways to function.

The porosity of the limestone is relatively low and

consequently, so is the specific yield (a

dimensionless aquifer parameter) for an unconfined

aquifer, estimated in one area to be 0.02.

Groundwater quality is an issue because of potential

effects on construction materials. Infiltrating waters

are under-saturated with respect to the minerals in




the rock fabric and the recharge-through flow

process causes these minerals to be taken into

solution. Using Electrical Conductivity (EC) as a

guide to total dissolved solids, background levels of

10,000-20,000µohms may be expected in

groundwater but a study in 1983 showed that in

many parts of central Doha, the levels were 3000-

6000µohms due to dilution by urban leakage.

Highest levels may be found in the coastal areas

reclaimed from the sea.

4.2.4 Summary of Relevant Conditions

A summary of the main conditions relevant to

drainage design is as follows:

• Most of the country is directly underlain by

the Simsima Limestone member of the

Dammam Formation which stores and

transmits groundwater via fissures that are

opened up by solution;

• Below the Simsima are the Midra Shales, an

aquiclude, and below that, a major aquifer,

the Rus Formation;

• Dissolution of anhydrite in the Rus causes

collapse in the strata above it and the

occurrence of depressions in the

topography;

• In Doha, the water table in the Simsima is

shallowest near the coast and beneath

depressed areas. Superimposed on

seasonal variations due to recharge from

rainfall, is a general rise in water table levels

due to urban leakage;

• In several areas of low elevation, recharge

events, coupled with shallow groundwater

levels may result in water table levels rising

above ground level during and after rainfall;

• The permeability of the shallow ground is

variable according to the incidence of

fissuring;

• The variation in permeability and the

elevation of the groundwater are critical

factors in the ability of soakaways to function

effectively;

• Groundwater generally has a high

conductivity but recently recharged waters

are under-saturated with respect to sulphate

and carbonate minerals;

• The groundwater conditions described

herein are only a general guide to the

hydrogeological conditions that may

characterise individual areas and site-

specific investigations are always required

as the basis for appropriate drainage design.

4.3 Construction Materials

As pipeline material on foul sewerage, surface

water, groundwater control and treated sewage

effluent (irrigation water) contracts can constitutes

around 15% of the capital costs of a projects in

Qatar, it is essential that suitable materials are

selected for the long term benefit of the Client. The

design principles adopted for a particular system

may reduce the number of options on material

selection either from cost or geological /

geographical standpoint.

Established international standards and guides such

as BS, ISO, ASTM, WIS, and WRC should be

followed in the selection of and specification for

Construction Materials. Ideally, the material product

should be covered by an established ISO 9000

Quality control system and wherever possible a third

party quality assurance scheme e.g. BSI (see

QA/QC Section 4.3.3).

4.3.1 Materials Selection

General

In order to determine if a material is suitable for

inclusion in foul, SW or TSE projects, several factors

have to be considered. These include:

• Suitability for intended purpose;

• Availability of material locally and cost;

• Capital cost of selected material offset

against reduction or elimination of

maintenance costs;

• Capital cost of installation by trenchless

methods offset by reduction in disruption to

traffic etc.;




• Quality of the medium being transported;

• Ground conditions (strata and groundwater);

• Difficulties in handling, transporting and

installing the material;

• Environmental conditions within the network,

such as high temperature, poor ventilation

high levels of corrosive products and

significant sand accumulation;

• Future use of land.

The selection of materials should strive to maximise

all options available to provide the lowest total

installed cost of the system without compromising

the long-term performance.

The conveyance of sewage, combined with poor

ventilation and high temperatures creates anaerobic

conditions resulting in the creation of hydrogen

sulphide (H2S). This in turn will convert to sulphuric

acid, which is highly corrosive to cementitious and

ferrous materials (see also Volume 2 section 1.6).

Caution should be exercised in Industrial areas

where dumping of neat waste into sewerage or

drainage networks, in the absence of local

legislation, may result in abnormally high

concentrations of corrosive products in specific

locations of the network.

Pipes

The DA preferences for materials used in SW,

sewerage and irrigation networks are included in the

following sections of this manual:

• Foul Sewerage – Volume 2, Sections 1.7.1

and 2.5;

• Surface Water and Groundwater Control –

Volume 3, Section 1.1.3 and 2.5;

• Treated Sewage Effluent – Volume 4

Section 4.2.7.

WRC Pipe Materials Selection Manualiv and EN

1295-1:1997v should be used as guidelines where

appropriate.

The material for a pipeline must be selected to suit

the liquid being conveyed and the installation

conditions. Table 4.3.1 highlights the suitability of

each type of material for various systems together

with Client’s preference, manufacturing base, and a

guide to the relative cost of each material. The table

is not exhaustive on labour and jointing costs. This

table is presented only a guide, as prices for

materials and labour vary with prevailing economic

conditions. Table 4.3.1 also provides a brief

summary of the materials acceptable for foul, SW

and TSE applications in Qatar.

Structural Behaviour & Classification of Pipes

A buried pipe and the soil surrounding it are

interactive structures. Pipes are generally classed

into “rigid”, “semi-rigid”, or “flexible”, depending on

the degree of this interaction.

Rigid pipes are those where, due to the nature of the

pipe material, only very small diametrical (ring)

deflections are possible before fracture occurs at a

well defined limiting load. These deflections are too

small to develop significant lateral passive pressure

in the pipe zone fill material (i.e. the soil surrounding

the pipe) due to external vertical loading. Thus all

the external load is taken by the pipe itself and

bending moments are induced in the pipe wall. The

design of rigid pipes is based upon the concept of a

maximum loading at which failure occurs.

Some examples of rigid pipe are RC, VC and AC

(Note that AC pipes are no longer acceptable in

Qatar).

Semi-rigid pipes are capable of being distorted

sufficiently without failure to transmit a part of the

vertical load to the pipe zone fill material. This

mobilises a measure of lateral passive support from

the surrounding soil, with the pipe wall continuing to

take the remainder of the load in bending.

Resistance to vertical loading is thus shared

between the pipe wall itself, and the lateral support

from the pipe zone fill material. The proportions of

this distribution depends upon the relative stiffness

of the pipe and the soil surround.

Some examples of semi-rigid pipe are ductile iron

(DI), and cylinder type pre-stressed concrete.

Flexible pipes are capable of being distorted

sufficiently without failure to transmit virtually all

vertical load to the surrounding pipe zone fill

material for lateral support; the proportion of the load

resisted by the pipe wall itself is very small. Flexible

pipes are designed on the basis of maximum

acceptable deflection (or strain induced in the pipe

wall), and resistance to buckling under load.




Some common flexible types of pipe are

unplasticised polyvinyl chloride pipe (PVC-u Note

that PVC is not acceptable on DA projects),

polyethylene pipe (PE), glass reinforced plastic pipe

(GRP) and glass reinforced epoxy pipe (GRE).

Pipe Bedding

The selection of the proper type of bedding and

surround material is important in the long-term

integrity and performance of both rigid and flexible

pipes.

Although rigid pipes support vertical loads mostly

through their inherent strength, and little support is

generated by the horizontal soil reactions, the

bedding can significantly increase its load bearing

capacity by ensuring a more even distribution of

vertical loads onto the pipe itself. It also allows

transmission of the load by the pipe to the trench

formation beneath.

There is a much greater interaction between flexible

pipes and the pipe zone material. The integrity of a

flexible pipe is therefore critically dependent on the

width and degree of compaction of the pipe bedding

material, and the stiffness of the native soil. A

flexible pipe should be totally surrounded with

granular bedding material. Sufficient trench width

each side of the pipe is essential to allow correct

placement and compaction of the granular bed and

surround. Incorrect placement will lead to distortion

of the pipe walls. A geotextile membrane is often

employed to avoid loss of fines from the native soil

and/or to stiffen up the pipe zone material. This is

particularly important in Qatar, where settlement

around manholes continues to be a problem.

Joints

Joints are an essential component of any pipeline

system, providing continuity between individual

pipes. The number and type of joints can

considerably affect cost and timescales for a

particular pipeline.

For buried pipelines it is important to allow for some

movement of the pipeline which occasionally occurs

through differential settlement of the soil. There are

three principal types of flexible joint:

1) Spigot and socket.

2) Sleeve coupling.

3) Bolted coupling.

Push fit spigot and socket joints comprise a belled

end (socket) integrally formed at one end of the

pipe. This has a slightly enlarged internal diameter

sized to receive the spigot end of the next pipe.

Sealing of the joint is achieved with flexible

elastomeric gaskets (sealing rings) which allow a

limited degree of angular rotation and longitudinal

movement without risk of leakage or fracture.

A sleeved coupling comprises a short cylinder into

which the machined ends of the two pipes are

inserted. Sealing is affected by two elastomeric

gaskets, one for each end of each pipe, which also

allow movement of the joint. The sleeve can have a

raised ring, or central locating register on the inside,

to ensure that the pipes are correctly inserted.

Bolted couplings comprise a cast iron or steel

sleeve, which is located over the ends of the two

pipes to be joined. Detachable flanges, located

outside the sleeve are bolted together, compressing

rubber gaskets on the outside edges of the sleeve to

effect sealing of the joint.

Joints can also be formed by solvent welding (PVC-

U pipes) and in-situ lamination (GRP pipes). The

pipes themselves are flexible and can accommodate

limited differential settlement through longitudinal

bending.

For HDPE pipes and fittings, two types of fusion

welding of joints are available – butt-fusion welding

and electrofusion welding. The latter method is

expensive and should be avoided where possible.

Universal mechanical couplers are also available,

particularly for jointing HDPE to pipes/fittings

composed of different material. Flanged joints can

also be formed, generally comprising a slip-on

galvanised mild steel flange restrained by an integral

stub return on the pipe end.

Pipe Handling, Storage and Laying

It is imperative that Manufacturers’

recommendations for handling, storage and laying

are strictly followed. Each material has its frailties

and rejection and repair strategies should be

assessed at tender stage.

The Manufacturer should be encouraged to attend

site to evaluate the performance of the contractors’




personnel to handle, store and more importantly to

correctly install and backfill the pipes to provide

optimum performance throughout the lifetime of the

pipes.

Lining

Ductile iron pipes for sewage use require lining with

epoxy or polyurethane.

Ductile iron pipe for TSE or storm water require

lining as above or with cement mortar.




Table 4.3.1 - Summary of Properties of Pipe Materials

HDPE GRP Ductile Iron Concrete VC

Specification

PrEN 12201

WIS 4-37-17

ISO 4427

DIN 8074

ASTM D1447

ASTM D 3035

ASTM C128

AWWAC 400

BS 486

ISO R160

BSS 5480

ASTM D3262

ISO – 2531

ISO – 8179

Coating

BSEN 545

BSEN 548

BSEN 639

BSEN 642

BSEN 1916

BSEN 5911

BSEN 295

BS 65

ASTM C700

DIN 1230

Maximum

Operating

Pressure

2.5 Bar to 30 bar Maximum 24 Bar Maximum 25

Bar

Prestressed to

20 Bar 10 Bar

Structural Type Flexible Flexible Semi Rigid Rigid Rigid

Standard Length

coil up to 180mm

dia

> 12m length

above 180 mm

6m 5/6m to 2.5m to 3.0m

Jointing

Butt Fusion

welding, Electro

Fusion, Flange

Push fit rubber

Gasket collar joint

Spigot – socket

with gasket slip-on

collar, flange

Push fit spigot

and socket /

flanged joints

Spigot and

socket

or welded steel

for pressure

pipe

Push fit with

rubber gasket

Anchor Blocks Not required on

welded lines Required Required Required Required

Fittings

HDPE Fabricated

fittings, standard

mechanical joints

GRP D.I. Fittings Concrete

(Limited) VC

(Limited)

Deflection Allowed More than 50

35 D radius Max. 50 Up to 50 up to 20

Up to DN 200

2.90

For 1000mm 0.60

Trench Required Narrow Trench Wide Trench Wide trench Either Wide Trench

Installation

Can be laid over

ground / under

ground on slopes

Underground Over Ground

Under ground Underground Underground

Corrosion

Resistant to soil

corrosion. Not

suitable for

contaminated

land

Resistant to soil

corrosion. May be

susceptible to

degradation by

organic

contaminants

Affected by

certain soil

chemicals

Affected by

certain soil

chemicals

Resistant to soil

corrosion

Chemically inert

Weight Light weight Light weight Heavy Heavy Heavy




HDPE GRP Ductile Iron Concrete VC

Handling Easy handling, not

easily damaged

Very Careful

handling, cracks if

badly handled

Can be

damaged by

heavy handling

Robust Careful handling,

brittle

Hydraulic

Properties

Low frictional

losses, low

pumping costs

Low frictional

losses, low

pumping costs

Low frictional

loss when lined Moderate friction

Low frictional

losses

Abrasion

resistance Good Good

Lining subject

to abrasion High Good

Breakage Impact resistant

unbreakable

Impact load cause

cracks

Damaged due

to heavy

impact loads

Robust Damage by

impact

Installation

Easy installation,

Less time required

Only very large

sizes need

craneage

Very careful

installation required.

Easy

installation,

larger sizes

need craneage

Easy installation

Easy installation,

many joints due

to small length

Bedding

Requirements

Selected as dug

material, target

90% standard

Proctor.

Granular surround

important to

support along entire

length must be self-

compacting

As dug

material Granular

Selected as dug

material or

processed

granular

materials, target

90% Proctor

Leakages No Leakage Normal Normal Normal Normal

Surge Head

Low wave

velocity

Less surge pressure

Medium surge

pressure. Poor at

cyclic loading

High surge

pressure n/a in Qatar n/a in Qatar

Deterioration with

time Nil

Joints deteriorate,

encrustation etc.

Corrosion

encrustation etc.

Good durability

when correctly

selected

Joint deterioration

Availability Local up to 1200

UAE UAE

Imported from

Europe, USA

or Japan

UAE Saudi Arabia

UV Light Deteriorates in

UV Deteriorates in UV Not affected Not affected Not affected

Cost Moderate Moderate High Low Low

HDPE GRP Ductile Iron Concrete VC RC




Use

in Qatar Foul

X

(Not preferred , but

sometimes used as

liner for pipejacks)

GRP + Conc

surround >1200

dia

Common in

pump mains X

To 1200

dia

SW X a a a To 1000

mm

> 1000

mm

TSE a� a a X X X




4.3.2 Structures

Concrete

Concrete is produced locally using locally sourced

materials (cement, aggregates, clean water,

admixtures etc). Approved readymix companies and

pre-cast yards should be selected to provide

concrete. Auditing of the facilities is essential to

verify that a quality product is supplied.

A good guide for properties of concrete constituents

and properties is provided in the CIRIA Guide to

concrete construction in the Gulf regionvi. Also useful

is ACI 305R Hot weather concretingvii.

Generally, two classes of concrete are required to

be designed for use on networks. A structural grade

will reflect the compressive, tensile strength and

durability requirements. This will have a water-

cement ratio less than 0.4, minimum 28-day

compressive strength of 40N/mm2, with durability

properties e.g. RCP value less than 4000 Coulombs.

A non-structural grade is required for blinding etc.,

where strength and durability are not a major

requirement.

Concrete mix designs should be designed to BS

5328viii or equivalent. Trial mixes should be

conducted on each mix to confirm the suitability and

the properties of fresh concrete and hardened

concrete. The approved mix designs should be

continually assessed by frequent site sampling and

testing. Limits should be derived from the trial mix,

which will govern the quality of the concrete supplied

throughout the remainder of the project using that

particular mix design.

Concrete-General

All concrete used in construction work must have a

certain strength, regardless of its application.

However, a high strength alone does not guarantee

long-term performance of a concrete structure. The

durability of concrete is probably the single most

important property.

The durability of concrete can be defined as its

ability to resist weathering action, chemical attack,

abrasion, or any other form of deterioration. A

durable concrete should maintain its original form,

quality and serviceability when exposed to the

surrounding environment for a long service life.

Water is responsible for many types of physical

processes of degradation. It also serves as the

carrying agent of soluble aggressive ions that can

be the source of chemical processes of degradation.

Tests and field experience have demonstrated that

compressive strength is the most important single

factor controlling the physical degradation of

concrete.

Generally, two factors leading to the chemical

degradation of reinforced concrete are sulphate and

chloride attack. Sulphates and chlorides are found

in abundance in the soil and groundwater in Middle

East. The sulphates attack the concrete, while the

chlorides cause corrosion of reinforcing steel. The

chemical processes involved in both cases are

complex and these are described briefly in the

following section.

• Ordinary Portland Cement (OPC) Versus

Sulphate Resisting Cement (SRC)

The British and American Standards

governing Portland Cement classify several

different types of cement based on their

chemical compositions. The differences in

chemical composition impart different

properties to the cements.

• Classification and Applicable Standard

There are five general types of cement

classified by ASTM C 150ix. The five types

are designated as Type I through Type V

with each classified for a particular type of

application based on its properties. OPC is

designated as Type I and SRC is designated

as Type V.

• Additives

Relatively small quantities of other materials,

called additives or admixtures, can be added

to concrete to modify its properties in either

fresh or hardened state.

The additives used to modify the properties

of fresh and hardened concrete are of the

following general categories:

1) Water-Reducing admixtures and

workability aids.




2) Superplasticizers and high-range

water-reducing admixtures.

3) Air-entraining agents.

4) Accelerators and “antifreezes”.

5) Retarders.

6) Waterproofers.

7) Viscosity modifiers.

8) Resin bonding agents.

In general a well-produced Portland cement

concrete, with appropriate protection when

necessary, will perform adequately for the

duration of its design life without the need for

any expensive property-modifying additives.

The following simple measures if

implemented and strictly enforced will

significantly improve the durability of

concrete.

1) Use of high quality aggregates.

2) Use of minimum water-cement ratio.

3) Avoidance of segregation and

elimination of bleeding.

4) Use of properly-timed finishing and

curing procedures.

5) Use of surface barrier sealants and

coatings, waterproofing membranes,

etc.

The use of concrete additives should be

evaluated on a case-by-case basis for

particular applications. If required to be

used, ASTM C 494x and BS 5075xi should

be referred to for specification requirements.

• Protective Coatings and Linings

The service environment of network

structures in the Middle East is considered

very severe. High concentrations of sulphate

and chloride ions in the surrounding soil,

groundwater and effluent present an

environment which makes all concrete

structures susceptible to significant

deterioration. New structures should be

properly protected by means of surface

barrier sealants, coatings and membranes in

order to preclude chemical attack and

significantly improve their service life. The

protection of concrete will be necessary for

buried structures and exposed structures.

For buried structures, an external

waterproofing membrane should be applied

to all surfaces. The membrane can be either

a self-adhesive or a torch-applied type,

consisting of a rubberised bituminous

compound coated to one side of a

polyethylene sheet. Alternatively, the

waterproofing membrane may be a liquid-

applied elastomeric type.

It is worth noting that in hot climates,

problems can be experienced with the self-

adhesive type membrane. The bituminous

compound softens in the heat when exposed

to direct sunlight for a long period of time

and the membrane will sag or slide off

vertical surfaces if not protected or backfilled

soon after application. The torch-applied

protective membrane is much more robust in

this regard.

Designers should note that the membrane,

whatever the type, should be protected by a

suitable protection board so that no damage

occurs to it during backfilling operations.

For structures in splash zones (such as

headwalls, outfalls, etc.), where exposure to

wetting and drying cycles are expected, the

exposed concrete surfaces can be coated

with an epoxy coating to DA approval.

All concrete that is subject to exposure to

sewer , gasses should be lined with GRP or

painted with an epoxy paint system to

prevent acid and bacterial attack on the

concrete.

• Reinforcement Bars

1) Plain (Uncoated) Reinforcing Steel

Reinforcement used in DA projects

should be mild or high yield steel,

bending dimensions and scheduling

in accordance with BS 8666xii.

2) Epoxy Coated Reinforcing Steel.




Epoxy coated steel is widely used in ME

countries but may only be used on DA

projects in exceptional circumstances.

The advantages are that it significantly

improves the long-term durability of

concrete, due to corrosion resistance

against chloride attack.

The main disadvantages are the increased

construction cost for reinforced concrete and

the possibility of damaged epoxy coating

being undetected and used; damaged

coating can make the steel prone to severe

chloride attack.

Manholes

• Manhole construction

Manholes are generally designed in both

cast in-situ and precast concrete with

protective coatings on internal and external

faces.

For sewage applications the internal liner

must be corrosion resistant and generally,

GRP with a vinylester resin-rich outer layer

is used. For ease of construction it has been

found that use of double-skin GRP units as

shuttering has proved successful. The units

can be manufactured in one piece for small

depths but generally come as separate units

that have to be joined in-situ. Designers

should note that the joints must be made

watertight by application of an external

epoxy bandage to the outer faces, and

finished with epoxy putty on the internal

faces.

For stormwater and irrigation the manholes

are constructed by conventional shuttering

methods with external bituminous tanking

and an internal coating of solvent free epoxy

resin.

• Manhole Covers

In addition to being capable of withstanding

applied loads, covers must be durable.

Manhole covers are classified according to

load classes in relation to the areas in which

they will be installed. BS EN 124xiii provides

detailed requirements regarding manhole

covers.

• Step-irons and Ladders

The top of the rungs should have a non-slip

surface for safety reasons. Three types of

material may be used for step irons and

ladders on DA projects as follows.

1) Stainless Steel can be used for step

irons and ladders.

Although covered more fully in

QNBS, it is worth noting that the

designer should ensure that the

grade is type 316 S31 to BS 790 Pt.

1, or better. Lower quality ladders

may still be subject to corrosion in

harsher environments.

2) Encapsulated Step-irons.

These are galvanised mild steel with

an epoxy coating.

3) GRP Ladders.

4.3.3 Quality Control and Quality Assurance

Quality of a material can be defined as the ability to

satisfy defined, and implied, needs. This will often

include compliance with national or international

standards.

Quality is rarely achieved without a formal system of

controls being established, and implemented. There

are three main requirements to ensure that quality

standards can be achieved in a reliable and

predictable manner:

• Quality Control (QC): A system of

documented procedures for manufacturing

and inspection;

• Quality Assurance (QA): The

implementation of the quality control system

by routinely providing evidence that all

reasonable actions have been taken to

achieve the required quality;

• Auditing: Routinely providing evidence that

the quality control system is being

implemented and that all reasonable actions




have been taken to achieve the required

quality.

Quality management systems (not product

standards) are now governed by ISO 9001:2000

Quality Management Systems – Requirementsxiv. It

is becoming increasingly recognised world-wide that

mandatory implementation of these standards does

significantly help achieve desired quality standards

and it is recommended that the DA insist that

suppliers have quality systems in place which are

regularly verified by certified external auditors before

their materials are approved for use.

The choice of material and a high standard of

specification alone cannot guarantee the satisfactory

performance of a drainage system. Improper

handling or installation of a high quality product will

render it inferior. For example, GRP pipes are

susceptible to impact damage during installation,

which can easily occur without proper training of

operatives and with poor supervision. Such damage

is not easily detected by visual examination and can

cause cracking of the fibre-resin matrix leading

possibly to the eventual failure of the pipe.

In concrete construction, the durability of an

otherwise superior mix is significantly reduced if

poor placement practices result in inadequate

compaction, honeycomb formation, and insufficient

hydration due to improper curing.

4.4 Design Standards, Procedures and Calculations

Design standards are detailed in the following

Sections:

• Volume 1 - Foreword i)

• Volume 1 - Section 1.5




Calculations are to be produced when necessary as

detailed in the technical sections of this Manual.

4.5 Standard Drawings

Volume 8 contains a complete list of all Standard

Drawings. Sections of the same drawings are

reproduced in Volumes 2, 3, 4, 5 and 6 as A3

appendices for ease of handling.

Standard Drawings were obtained from the DA for

incorporation into this Manual. In addition, a large

number of typical drawings is also presented. The

Standard Drawings must be used in their original

format without alterations. Where used in contract

documents their numbers shall remain unaltered,

and may be referred to without the need to

incorporate as hard copies into all documents.

Typical drawings have been developed from a

number of past DA projects, and are presented as

an indication of standard format and quality. These

may be used as the basis of individual contract

drawings but must be renumbered and edited

accordingly for specific projects.

It should be noted that the typical drawings include

only drawings developed from previous projects. It

is the DA’s intention that the list be supplemented by

new drawings from other projects as they become

available. The list includes:

• Sewerage Standard Detail;

• Sewerage Standard Details for manholes,

miscellaneous chambers and septic tanks;

• Surface Water Details for manholes and

miscellaneous chambers;

• TSE and Irrigation Drawings containing

general layout plans, chamber and

protection bollard details;

• General Details Drawings containing thrust

blocks, pipe bedding details, boundary wall

and gates details, and sign and notice board

details;

• Sewage Treatment Works Typical details

covering typical general arrangements, plant

layouts, landscaping, process and hydraulic

profiles;

• Non-Disruptive Pipeline Construction

Drawings containing details of pipelines,

thrust and reception pits;




• Service Reservation Detail Drawings

containing details of service reservations

corridors;

• Pumping Station Standard Detail Drawings

containing site layout plans, general

arrangements, elevations, details of

chambers, boundary walls and

miscellaneous works.

All other drawings should be produced in

accordance with the CAD Manual, Volume 6. It

should also be noted that, where projects infringe

upon highways, traffic management measures will

be required, and the consultants will be expected to

produce traffic management drawings to suit the

requirements of the project, to satisfaction of the RA

and DA.

4.6 Building Permits

Building permits will be required for any new building

or structure which requires utility connections. The

stages required to obtain a building permit are:

• Open a building permit file at the Planning

Department;

• Obtain Initial Design Control (DC) 1

approval;

• Obtain utility approvals;

• Obtain Final DC1 approval;

• Obtain DC 2 approval;

• Collect building permit.

These are described in more detail below.

4.6.1 Opening a Building Permit File

Depending on the location of the project the building

permit file need to be opened at either Doha,

Rayyan, Al Khor or Wakrah Municipality. To open

the file drawings showing the location and general

arrangement of the building/structure and the land

ownership, details from the Lands Information

Department will be required.

4.6.2 Initial DC 1 Approval

To obtain this the consultant must present drawings

showing:

• Site location;

• General Arrangement of Site;

• Plot details including plot number, total plot

area, area of proposed works, proportion of

works to plot area, and overall dimensions of

plot. These are to be consistent with the

Ministry of Lands Information plot details.

At this stage the municipality will advise on the

service authorities from whom approval will be

required. These will be selected from the following

list depending on the scope of work:

• Roads Affairs;

• Electricity Networks;

• Civil Defence Department;

• Water Networks;

• Q-Tel;

• Drainage Affairs;

• Police.

4.6.3 Utility Approvals

Roads Affairs

Drawings submitted to the RA are to show the

surrounding road corridors and design details as

available. Points of vehicular ingress and egress

with access roads, gate details etc. must also be

indicated.

Electricity Networks

Electricity networks will require details of buildings

which will contain electrical equipment and site

layout showing cable routes, duct provisions,

electrical items, including small power and lighting,

to be installed and meter cabinet. A single line

diagram showing details of all distribution boards

and total demands is to be supplied. It is important

that the QGEWC Building Permit Application Form is

completed consistently with the single line diagram.

Thermal insulation calculations for the building will

also be required. Digital and A3 size hard copies of




all the drawings are to be submitted prior to final

approval.

Civil Defence Department

Details of all fire alarms and fighting equipment are

to be included on the drawing submitted for

approval.

Water Networks

The provision of a water meter cabinet has to be

made whether a supply is currently available or not.

This is to be shown on the drawings together with

any existing or proposed water network pipes.

Copies of all drawings are to be submitted in digital

format.

Q-Tel

The drawing submitted for approval is to show the

point of supply, the duct from the plot boundary to

the internal sockets and any additional internal

sockets. Drawings showing site location and site

layout will also be required. Copies of all drawings

are to be submitted in digital format.

Drainage Affairs

The DA will require a site layout showing the

sewerage outlet and connection to the sewage

network or location of septic tank with provision for

connection to the future network for approval.

Police

Police approval is infrequently required and would

relate to matters such as vehicular access to

developments which are open to general public,

such as sports stadiums and shopping malls.

4.6.4 Final DC1 Approval

Once all the requisite service authority approvals

have been obtained they should be returned to

municipality with the original file so that final DC 1

approval can be given.

4.6.5 DC 2 Approval

DC 2 approval relates to the structural elements of

the building or structure and architectural and

structural details will must be submitted as follows:

• Structural drawings, three copies;

• Architectural drawings, three copies;

• All approved utility drawings;

• Digital copy of the site layout drawings in the

municipality’s format;

• Drawing list of all submitted drawings.

4.6.6 Building Permit

Once the DC2 approval has been given the Building

Permit will be prepared and can be collected from

the municipality following the payment of fees which

are dependant on the nature of the project.

4.7 Environmental Design

This section provides guidance on sewerage and

drainage project design and the potential for impact

on the environment. As with all environmental

management activities in the sewerage and

drainage sector, the need for an integrated

approach, including extensive consultation with

planning authorities, SCENR, and DA staff is re-

iterated.

The pollutants in municipal wastewater are

suspended and dissolved solids consisting of

inorganic and organic matter, nutrients, oil and

grease, toxic substances and pathogenic micro-

organisms. Urban storm water can contain similar

pollutants, sometimes in surprisingly high

concentrations. Human wastes that are not properly

treated, and disposed of at source, or collected and

carried away, pose high risks of parasitic infections,

hepatitis, and various gastro-intestinal diseases

including cholera and typhoid (through

contamination of water supplies and food).

When wastewater is collected but not properly

treated before disposal or reuse, health hazards

exist at the point of discharge. If the discharge is to

a confined lake (see Volume 3, Section 1.1.2) then

its nutrient content can cause eutrophication, with

nuisance algae and plant growth that can cause

odour, and disrupt fisheries, recreation and/or

conservation. Solid waste generated as part of the

wastewater treatment process (grit, screenings,

sludge) can pollute soil and groundwater if not

properly managed.




Wastewater projects are implemented in order to

prevent or alleviate the potentially significant

negative effects of the pollutants described above

on the human and natural environments. When

properly carried out as part of an EIA and

sustainability procedure, their overall impact is

positive. Direct beneficial impacts include

abatement of nuisances and public health hazards

in the serviced area. In addition, an opportunity for

more effective control of industrial wastewater

through pre-treatment and connection to public

sewers offers the increased potential for beneficial

reuse of treated effluent and sludge. Indirect

impacts include the improved provision of serviced

sites for development, increased tourist,

conservation and recreational activity and revenues,

increased agricultural and silvicultural productivity

and/or reduced chemical fertiliser requirements,

alongside reduced demands for other water sources

as a result of effluent reuse. Public health

improvements, together with the above

improvements, result in strong positive social,

economic and environmental benefits that contribute

to the sustainable development of Qatar.

From the preceding discussion, it will be clear that

the environmental design procedure will follow on

from the drivers presented by Qatari environmental

law, the environmental scoping study (Section 2.7.4)

and the EIA (Section 2.7.5).

The environmental design process must follow on

from the mitigating measures identified in the EIA.

Where a design changes significantly during the

course of the project, the EIA must be reviewed and

amended accordingly. This is an iteration process,

and amendments will require approval by SCENR

via Q&SD. It is essential that monthly project

meetings are held between consultants PM, DA PC

and a designated Q&SD representative on all

environmentally sensitive projects.

4.8 Tendering and Contract Procedures

The types of contracts awarded by the Government

for DA works are:

• Professional Service Agreements;

• Conventional Construction Contracts;

• Design and Construct Contracts;

• Material Supply Contracts;

• Hybrid Contracts;

• Work Order Agreements.

Fig 1 in Appendix 4 illlustrates the procedure by

which contracts are tendered and awarded, in flow

chart format. In addition to this procedure,

consultants must be aware of the following:

• Once a tender document has received

approval it cannot be amended.

• Tender circulars may either be prepared by

the DA, for items such revisions to the

tender return date or the consultant for item

such as revisions to specification or

drawings. Numbering of circulars is to be

sequential;

• When tender enquiries are received from

tenderers the consultant is to review them,

advise the DA on any action required, and

prepare any necessary tender circulars;

• On return of the tenders, the consultant will

undertake the technical and final review of

the tenders as per the PSA requirements;

• During the design period the estimated value

of the works to be constructed, construction

period and likely start date will be

determined and finalised. During this period

the DA will keep DOFA advised of cash flow

requirements for approval and re-approval

as found necessary. The consultant is to

provide in a suitable format all the necessary

information required by the DA to fulfil this

obligation.

The use of the above noted contracts will be

dependent on the DA’s requirements as described

below.

4.8.1 Professional Service Agreement

These are utilised where services are to be provided

by consultants for activities such as:

• Master Planning;

• Feasibility Studies;




• Outline Designs;

• Detailed Designs;

• Record Surveys;

• Specialist Investigations;

• Specialist Services.

• Site Management and Supervision

These are based on the Professional Service

Agreement General Conditions of Engagement

1984xv, as expanded and modified by the particular

Fee Tender Professional Consultancy document. It

will comprise:

• Form of Tender;

• Instruction to Tenderers;

• Conditions of Engagement;

• Specimen of the Consultancy Services

Contract;

• Project Brief;

• Tender Submission Schedules;

• Reference Documentation and Schedules.

Generally the Fee Proposal will comprise a single

combined technical and financial proposal.

However, for projects that require a high level of

technical expertise, outside the normal scope of

projects, a separate technical submission can be

specified. This will enable a full technical appraisal

and evaluation to be undertaken prior to the opening

of the financial offers.

4.8.2 Conventional Construction Contracts

These are utilised where a contractor is required to

undertake major construction works such as:

• Area drainage/sewerage schemes;

• Pumping Stations;

• Sewage Treatment Works;

• Refurbishment Works.

These are based on the General Conditions of

Contract prepared by the Ministry of Public Works

as expanded and modified by the particular Tender

Document, which will comprise:

• Form of Tender;


• Conditions of Contact;

• Project Specification;

• Bill of Quantities.

4.8.3

4.8.4 Design and Construct Construction Contracts

Design and build contracts can be advantageous:

• where an early start to construction is

desirable;

• when there is a substantial element of

electromechanical works which will dictate

the civil requirements;

• where it is desirable to use the special skills

of the contractors to design the works e.g.

treatment processes.

These are based on the General Conditions of

Contract prepared by the Ministry of Public Works

as expanded and modified by the particular Tender

Document, which will comprise:

• Form of Tender;


• Conditions of Contact;

• General Specification;

• Output Specification;

• Payment Schedule.

Design and Construct Contracts will generally be

valued at more than QR 3M and will be tendered by

the CTC.

4.8.5 Material Supply Contracts

Where materials only are required, the Standard

Supply Conditions of Contract are utilised. These

will comprise the following:

• Bill of Quantities;

• Specification;




• Tender and Contract Forms.

4.8.6 Hybrid Contracts

These are used when the other forms of contract are

not applicable. They have to be prepared on a one–

off basis for the specific requirements, and all of the

necessary approval procedures followed must be

based on internationally recognised Conditions of

Contract (eg flow survey contracts.

4.8.7 Work Carried Out Under Work Order Agreements

The DA is currently reviewing the procedure of the

issue of Work Orders and this section will be added

following the completion of the review.

4.9 Health and Safety and Security

The Health and Safety section incorporates many

features of international practice which are not yet

incorporated into Qatar legislation. This section will

be revised as necessary in the final document to

accord with Qatar procedures. The department is

currently drafting a revised policy statement, which

will be included, when Ministerial approval is

granted. Until this time, the policy stated below shall

be observed.

4.9.1 Policy Statement

It is the Department’s policy to conduct its activities

in a manner designed to minimise H&S risks, protect

the health and safety of its employees, consultants,

contractors, the community at large and the

environment in which the Department’s activities are

conducted.

The Department, through the active participation of

all employees, contractors and consultants will strive

to manage H&S risks with the goal of preventing

accidents, injuries and occupational illnesses, using

energy efficiently and producing safe, quality

products.

The Department considers that good H&S

performance is equally if not more important than all

other primary business objectives.

The Department expects all of its staff, contractors

and consultants alike to:

• comply with all applicable laws and

regulations, and apply internationally

recognised standards where local laws and

regulations do not exist;

• manage all risks to a level which is as low as

is reasonably practicable;

• design facilities, establish procedures,

provide training and conduct operations in a

manner that minimises risks and hazards to

workers, property, and the community at

large, applying best available technology,

consistent with good industry practice.

The Department will:

• hold all levels of line management

accountable for H&S issues and for the

development of positive attitudes in

themselves and those they supervise;

• provide H&S training to appropriate staff,

and will assist both the consultants and

contractors by providing with the relevant

advice and encouragement in the provision

of H&S training;

• ensure all operations are conducted with the

safety of the employee and community as a

primary objective;

• appoint a safety manager for all projects,

whose main role will be to provide the

required safety expertise to the department

and liase with Consultants via the Project

Co-ordinator’s safety related duties.

The Consultant shall:

• prepare and submit copies to the head of the

department, with copies to the department’s

safety manager, along with their company

health & safety policy and procedural

manual which outlines their company’s

proposal for effectively managing the H&S

aspects of their business and on all the DAs

building and construction contracts;

• during the design phase of each contract,

prepare a pre-tender H&S plan, which will

enable prospective contractors to be made

aware of the project’s main health and safety




issues. The pre-tender H&S plan should

contain enough information to allow

prospective tenderers to plan and price for

H&S on that particular contract. A copy of

the pre-tender H&S plan shall accompany

each tender;

• appoint a full/part time safety officer;

• report all accidents/injuries, dangerous;

• submit to the Head of the DA, with a copy to

the DA Safety Manager (safety unit), at the

beginning of each month using their own

company format, a brief summary of the

contractor’s safety performance on each of

their contracts during the previous month.

Where applicable, this should include copies

of any H&S site instructions issued to the

contractor during that period;

• arrange both the pre-construction and site

safety meetings;

• ensure, as far as is reasonably practicable,

that the contractor fully complies with the

appropriate H&S procedures and minimum

H&S standards laid down in the DA safety

manuals, and any other additional standards

either included in the contract specification

or agreed on-site;

• set a high example of health and safety on

all the department’s building construction

contracts.

The Contractor shall:

• at the tender stage, submit with the tender

documents, a copy of their company health

and safety policy and procedural

arrangements for effectively managing H&S

issues on all the DA’s building construction

contracts;

• include with the tender documents, a brief

summary and breakdown of moneys

allocated to effectively manage the main

hazards/risks identified in the pre-tender

H&S plan;

• on being officially informed of being awarded

the contract, to prepare and submit to the

Department Head, with copies to the

Department’s Safety Manager and

consultant’s site engineer, prior to, or at the

pre-construction meeting, a copy of their

proposed Health and Safety Plan specific for

that contract. This will be based on the

information received in the pre tender health

and safety plan they received with the

tender, and any other main risks or hazards

they themselves may have identified;

• are responsible for ensuring that their sub-

contractor(s) comply with the minimum H&S

standards laid down by the DA, and any

other additional standards either included in

the contract specification, or agreed on site;

• appoint a full/part time safety officer;

• submit risk assessments/method statements

for specific operations as directed by the

consultant’s site engineer and/or the

department’s safety manager;

• provide information on all

accidents/dangerous occurrences;

• attend safety meetings as directed by either

the consultant’s site engineer or the

departments safety manager;

• appoint a trained first-aider;

• submit monthly H&S reports to the

consultant’s site engineer;

• ensure that they fully comply with the

minimum H&S procedures and standards

laid down by the DA.

The Contractor’s policy document should

include, as a minimum:

• a written statement of their general policy with

respect to the H&S of their employees signed

by the managing director of the company;

• details of their safety organisation and its

function;

• safety responsibilities of all concerned;

• procedural arrangements for effectively

implementing the policy including:

1) provision of safe systems of work;

2) safety training;

3) safety committees;

4) accident reporting;




5) emergency procedures.

4.9.2 Accident Reporting

An accident is defined as an unplanned and

unexpected occurrence, which upsets a planned

sequence of work resulting in loss of production,

injury to personnel and/or damage to plant and

equipment.

Ideally, the causes of all accidents should be

established regardless of whether injury or damage

results. Where necessary, a full investigation should

be carried out and a record of accident classification

should be maintained. This will enable appropriate

preventative action to be taken should a pattern of

causation emerge.

The main purpose of this procedure is to firstly

ensure that all accidents, injuries and incidents are

properly reported and investigated in order that the

main cause(s) can be determined with a view to

preventing a recurrence. Secondly, this will enable

the gathering of statistical information so that any

particular trend can be identified and corrective

action taken.

Consultants, contractors and sub-contractors are

responsible for ensuring that all accidents occurring

to their employees are reported as follows:

• In the case of Death of any Person,

immediately Inform Police (999);

• In the case a Major Injury to, within 24 hrs

inform (either by fax or phone) DA Safety

Unit;

• In the case of both major and lost time

accidents to within 7 days, forward full report

of the accident to DA Safety unit;

• All minor accidents to be included in the

consultant’s monthly record of accidents

reports to the Department Safety Unit.

Note: where applicable, include any witness

statements, photographs, drawings etc.

4.9.3 Training

Introduction

The construction industry is labour intensive and, as

such, should regard its labour and trades staff as

one of its major resources. It is therefore important

that, in improving the quality of the industry, the

skills and knowledge of its personnel are also

improved.

As part of that improvement programme, the DA

firmly believe that providing the skills and knowledge

to facilitate the avoidance of accidents and

occupational ill health through properly organised

and structured safety courses, is of paramount

importance. As such, the DA requires consultants,

contractors and sub contractors to carry out, and

record, the following minimum safety training

requirements.

Training Required

Senior Management

• Includes directors, principals and others who

may be responsible for defining and

influencing the management of health and

safety at a senior level. In broad terms,

those who have overall responsibility for

matters of H&S and will be required to

establish and support the H&S policy and

allocate resources for the policy objectives

to be met;

• training syllabus should include, but not be

limited to the following:

1) management of health and safety;

2) legal obligations;

3) DA’s site safety procedures and

standards;

4) health and safety resources;

5) accidents and accident prevention;

6) hazards of toxic gases and COSHH.

Site Management

• Includes senior consultant site engineers,

consultant site engineers, contract

managers, project managers, contractors

site engineers, safety officers and general

foremen;

• training syllabus should include, but not





1) company health and safety policy

and procedural arrangements;

2) individual health and safety

responsibilities;

3) legal obligations;

4) DA’s safety procedures and

standards;

5) site safety management;

6) health and safety planning;


8) common health and safety issues

e.g. manual handling, welfare

facilities, personal protective

equipment (PPE) etc.;

9) specific training requirements e.g.

scaffolding, excavations, cranes,

confined space etc.;

10) hazards of toxic gases e.g. chlorine,

hydrogen sulphide and methane,

and procedure sin their safe handling

for all employees;

11) radiation safety for those involved in

industrial radiography on site.

First Line Supervision

• Includes supervisors, trades foremen,

chargehands and gangers;

• training syllabus should include, but not be


1) company health and safety policy

and procedural arrangements;

2) individual safety responsibilities;

3) DA’s safety procedures and

standards;

4) health and safety management;


6) standards of health and safety

provisions.

Site Operatives

Induction Training

• On recruitment, all site operatives should

receive a H&S induction course which will

alert them to:

1) their company health and safety

policy and procedural arrangements;

2) their individual health and safety

responsibilities;

3) procedures for the reporting of

accidents and dangerous

occurrences;

4) outline the management systems

which are in place to identify and

eliminate or minimise identified risks;

5) advise them of the role they have to

play to ensure that standards of

health and safety provisions are

maintained;

6) name and responsibilities of the

company’s safety officer;

7) availability, use and care of personal

protective equipment;

8) risks that are related to the tasks

they perform;

9) location of welfare facilities;

10) first aid, trained first aider and

location of first aid boxes;

11) fire arrangements, evacuation

procedure etc. in the labour camp.

On Site Training: (Tool Box Talks)

• The techniques for training operatives will

often be quite different from those used to

train first line managers. Operatives training

is normally site based, but that should not

give rise to any compromise in the careful

setting of training objectives and delivery of

the training by competent instructors working

in a suitable training environment. An

additional means of providing instruction and

training to operatives is in the form of “tool

box talks”.

These are brief instruction/training sessions

lasting approximately 20 to 30 minutes

duration dealing with specific subjects, and




ideally delivered by the safety officer with a

member of site management in attendance.

Specialist Training

• These will be courses designed to meet the

needs of specific operatives involved in

specialised trades and will include, but not


1) safe entry into confined spaces;

2) crane operation;

3) slingers/banksmen;

4) scaffolding;

5) abrasive wheels;

6) woodworking machinery;

7) excavation support equipment;

8) first aid.

4.9.4 Site Safety Meetings

Pre-Construction Site Meetings

To be organised by:

The consultant senior site engineer and/or

contractors project manager for the contract,

in conjunction with the DAs safety unit and

appropriate engineers and technical

inspectors.

To attend:

In addition to those normally invited to these

meetings, the following are also required to

attend for the safety agenda only:

• DA’s safety manager and/or

nominated member from the safety

unit;

• consultants full/part time safety

officer for the contract;

• contractors full/part time safety

officers.

H&S Agenda Items:

Health and Safety will be the first item on the

meeting agenda and will include, but not be limited

to the following:

• contractors health and safety policy, with

details of their safety organisation and

arrangements/procedures;

• arrangements/procedures for dealing with

sub-contractors;

• copy of their H&S plan indicating their

methods/proposals for either eliminating or

controlling the main hazards/risks identified

in the pre-tender H&S plan;

• their procedure for the reporting of

accidents/injuries and dangerous

occurrences;

• details of their appointed full time/part time

safety officer’s qualifications, experience etc.

together with his prime duties and

responsibilities;

• their arrangements and procedures for the

provision of trained first aiders, first aid

boxes and portable fire fighting equipment;

• ensure that the contractor has received a

copy of DA H&S policy;

• bring to the notice of the contractor DA

enforcement policy and financial penalties

for non-compliance.

Site Progress Meetings

To be organised by:

consultant’s senior site engineer and

contractors project manager for the contract,

in conjunction with the DAs appropriate

engineers and technical inspectors.

To attend:

In addition to those normally invited to these

meetings, the following are also required to

attend, for the safety agenda only:

• representative from the DA’s safety

unit;

• consultant’s full/part time safety

officer;




• contractor’s full/part time safety

officer for the contract.

H&S Agenda Items

Health and safety will again be the first item on the

meeting agenda and will include, but not be limited

to the following:

• matters arising and actions outstanding from

the previous meeting;

• on the agreed format, to receive from the

contractor details of any accidents/injuries or

dangerous occurrences reported;

• review any health & safety site instructions

issued since the last meeting;

• details, together with records of any safety

training carried out since the last meeting;

• any other matters relating to health and

safety.

4.9.5 Enforcement Policy

The DA, in its commitment to continuously improve

H&S standards may introduce an enforcement

policy, which will financially penalise contractors

who consistently violate the DA H&S procedures.

The enforcement policy will consist of two notices, a

Prohibition and an Improvement notice, and both

consultants and contractors should note that, failure

to comply with the requirements and time scale

indicated in any of these notices, will result in the

matter being referred to the Head of the DA.

On being informed of the violations, and after

confirming that these have still not been attended to,

the Dead of the Department will approve the fine

issued by the DA Safety Manager to the contractor

concerned, in line with the schedule of rates

published from time to time by DA.

In the case that fines which have already been

implemented, but still no action has been taken by

the contractor, the Head of the Department will refer

the matter to the QMMAA legal section.

Prohibition Notice

This will be issued by either DA’s Head of Safety

Unit and/or by the engineer/inspector responsible for

the contract. It will instruct the contractor to

immediately cease work when, in their opinion, the

violation noted could result in a serious or fatal injury

to the worker(s) involved in that particular operation.

Types of violation for which a prohibition notice

could be issued:

• scaffold platforms over two metres high

which are not properly boarded out, no

proper and safe access provided, and no

guard rails fitted;

• men working in areas without safety helmets

where overhead work is in operation;

• deep excavations where sides are not

supported or battered back to a safe angle,

and there is imminent danger of collapse;

• using cranes and/or lifting gear which,

because of their condition, or the manner in

which they are being used, could cause

serious or fatal injury during lifting

operations;

• cranes being used not being certified and

tested within the last twelve months.

Improvement Notice

This will be issued by either the DA’s Head of Safety

Unit and/or by the engineer/inspector responsible for

the contract, when he is of the opinion that, although

there is no immediate danger to life, items noted in

the notice are in contravention of procedures and/or

standards laid down by the DA H&S Section.

The contractor will be given 28 days to rectify the

violations indicated in the notice, following which, if

no action has been taken, he will be given a further

seven days. If no action has been taken after these

two warnings, penalties as indicated in the

introduction to this section will be imposed.

Types of violations for which an improvement notice

could be issued:

• non-appointment of full or part time safety

officer;

• not providing appropriate PPE e.g. head,

foot, ear, face protection etc.;




• untidy site;

• non-provision and/or maintenance of existing

welfare facilities;

• non-provision of fire fighting equipment;

• lack of proper security fencing;

• non-provision of appropriate safety signs;

• deficiencies in safety training requirements.

4.10 CDM Best Practice

4.10.1 Introduction

The Construction (Design and Management)

Regulations 1994, commonly known as the CDM

Regulations, came into force in the UK in 1995. The

Regulations, supported by an Approved Code of

Practice, brought about a major change in the

management of construction health and safety and,

in particular, imposed explicit statutory duties on

Clients, Designers and Contractors. Other EC

countries produced similar legislation. This section

of the Manual recommends how the main

requirements on Designers can be implemented in

situations where the Regulations do not apply in law,

such as in the State of Qatar, but may be used as a

means of ensuring Best Practice during design with

a view to increased health and safety during the

construction and indeed the maintenance of assets.

4.10.2 Earliest Involvement

Designers are in a unique position to reduce the

risks that arise during construction work. Designs

develop from initial concepts through to a detailed

specification, often involving different teams at

various stages. At each stage, designers from all

disciplines can make a significant contribution by

identifying and eliminating hazards and by reducing

the remaining risks. Designers’ earliest decisions

are crucial in that they influence later choices.

Considerable work may be required to unravel

earlier inappropriate decisions, so it is vital to

address health and safety at the very start. It is also

important to realise that designers’ responsibilities

extend beyond the construction phase of a project.

They also need to consider the health and safety of

those who will maintain, repair, clean and eventually

demolish a structure. Failure to address these

issues adequately at the design stage may make it

difficult to devise safe systems of work. It could

also cause additional costs later because, for

example, expensive scaffolding or other access

equipment is needed.

4.10.3 Co-ordination

It is essential that the input of all designers involved

on a project is properly co-ordinated. The lead

designer should take on the role of co-ordinator and

ensure full co-operation between all parties in order

to implement a ‘brainstorming’ approach to

‘designing out’ hazards and risks. In order for this to

be effective, there must be a broad definition given

to the term ‘designer’ to ensure that no-one is

missed out of this process. Therefore, the input of

the following should be included:

• architects;

• quantity surveyors;

• building service designers;

• those purchasing materials;

• contractors carrying out design work;

• temporary works designers;

• interior designers;

• heritage organisations.

4.10.4 Preparing the Design

Designers must critically assess the risk to those

people involved during construction. When the

design is being prepared, these risks don’t yet exist,

but there is already a potential for harm when the

work starts on site. The first stage in reducing risk is

to identify the hazards in the proposed design. The

next stage is to eliminate each hazard, if feasible.

Where it is not feasible to ‘design out’ a hazard, the

next stage is to consider what can be done to

reduce the risk and give priority to control measures

which will protect all those involved.

The designer should, where possible, select the

position and design of structures to minimise risks

from the following hazards:

• buried services, such as electricity and gas;

• overhead cables;




• traffic movements;

• contaminated ground;

Health hazards should be ‘designed out’ by:

• specifying less hazardous materials, e.g.

solvent-free or low solvent adhesives and

water-based paints;

• avoiding processes that create fumes,

vapours, dust, noise or vibration, e.g. by:

disturbing asbestos, cutting chases in

brickwork and concrete, breaking down cast

in-situ piles to level, scabbling concrete,

using hand-held tunnelling machines, flame

cutting or sanding areas coated with lead

paint or cadmium;

• specifying materials that are easier to

handle, e.g. lighter weight building blocks.

Safety hazards should be ‘designed out’ by

avoiding:

• the need for work at height;

• fragile roofing materials;

• deep or long excavations in public areas or

in highways;

• materials that could create a significant fire

risk during construction.

Designers should consider prefabrication to

minimise hazardous work or to allow it to be carried

out in more controlled conditions, e.g. by:

• designing elements such as structural

steelwork whereby it can be erected at

ground level and then safely lifted into place;

• arranging for ‘cutting to size’ to be done ‘off-

site’ under controlled conditions to reduce

the amount of dust released.

The designer should include features that reduce

the risk of injury, e.g. by:

• the early installation of permanent access,

such as stairs to reduce the use of ladders;

• designing permanent edge protection at

height;

• providing lifting points at marked centres of

gravity of awkward items requiring ‘slinging’

on drawings and on the items themselves;

• making allowance for temporary works;

• considering the stability of partially erected

structures and, where necessary, providing

information to show how temporary stability

could be achieved during construction;

• identifying hazards that may arise during the

eventual demolition of the structure being

designed (refer to section 4.10.6 ).

4.10.5 Health and Safety Plan

Designers (together with clients, if appropriate) must

include adequate health and safety information with

the design. This includes information about hazards

that the designer has not been able to eliminate,

reduce or control, and will consequently remain a

design hazard during construction. Such information

should be included in a document referred to as the

pre-construction Health & Safety Plan. It should

contain details of all the significant residual risks

facing contractors and should include any

assumptions about working methods or precautions

to be taken into account by contractors.

A section of the Health and Safety Plan should

contain the Hazard and Risk Assessments

(HARAS), which will have been produced by the

designers. The HARAS will contain all of the risks

identified during the assessment, together with all of

the mitigating measures as appropriate. An example

of a HARA is included in Appendix 1.

Designers do not need to mention every hazard or

assumption, as this can obscure the significant

issues. Significant hazards are those that are:

• not likely to be obvious to a competent

contractor;

• unusual; or

• likely to be difficult to manage effectively.

To identify significant hazards, designers must

understand how the design can be built.

Examples of significant hazards to be included in the

pre-construction Health & Safety Plan are:

• hazards that could cause multiple fatalities to

the public, such as tunnelling or the use of a

crane close to a busy public place;




• temporary works required to ensure stability

during construction;

• hazardous or flammable substances

specified in the design, e.g. epoxy grouts,

fungicidal paints or those containing

isocyanates;

• heavy or awkward prefabricated elements

likely to create risks in handling;

• areas needing access where normal

methods of tying scaffolds may not be

feasible.

Information should be clear, precise and in a form

suitable for the users. This can be achieved by

using:

• notes on drawings;

• a register of hazards with suggested control

measures;

• suggested construction sequences showing

how the design can be erected safely.

4.10.6 Health and Safety File

Designers (together with clients and contractors)

should also provide health and safety information

needed by people carrying out cleaning work,

maintenance, alterations, refurbishment and

eventual demolition of the structure being designed.

This information is included in a document referred

to as the Health & Safety File, which is handed to

the client or operator of the asset at the end of the

construction phase. Such information could include:

• ‘as built’ drawings of the structure, its plant

and equipment;

• information on remaining hazards (e.g.

asbestos or contaminated land) and how

they should be managed;

• HARAs (see 4.10.5);

• key structural principles incorporated in the

design of the structure (e.g. bracing, sources

of substantial stored energy including pre or

post tensioned members) and safe working

loads for floors and roofs;

• information on hazards associated with

materials used, e.g. lead paint;

• information regarding the removal or

dismantling of installed plant, e.g. lifting

equipment;

• information about equipment provided for

cleaning or maintaining the structure;

• the location and markings of significant

services such as fire-fighting services.




5 Reporting Systems

5.1 General

Each project has its own specific technical brief and

design process. During this design process a

standard reporting system is to be followed for each

of the main design stages:

• Sketch Stage;

• Preliminary Stage;

• Investigation Stage;

• Detail Design and Tendering Stage;

• Documentation;

• Engineering Report;

• Supplementary Reports.

Basic requirements for each report stage are given

in the ‘Professional Service Agreement General

Conditions of Engagement’, 1984xv, which will be

amended and amplified by the particular terms of

reference for the project. The investigation stage

noted above will often overlap between sketch and

preliminary stages. It may be carried out by the

consultant or another contractor. However, the

consultant will need to review any reports produced

by such contractors for completeness in relation to

the PSA.

The objective of each report is to describe the

design activities up to that stage and to clearly state

the specific requirements required by the project

brief for that stage, as outlined below. Prior to

submission of any report the following quality

assurance procedures are to be carried out.

5.1.1 Quality Control

Each report is to be given a specific sequential

number prefixed by the letter R i.e. R01, R02, R03,

etc.

Where a report consists of more than one volume

each volume is to be numbered as follows R01/A,

R01/B, R01/C, etc.

Revisions to reports: the initial issue of a report is to

be denoted as (Rev A) with subsequent revisions

progressing in alphabetical order. If a volume of the

report remains unchanged through a revision

change it should be reissued with the new revision

number.

Drawings and figures included in reports need not

have the report revision number, but where

drawings have been revised from previous issues

they must be given the next revision letter. Each

report is to include a drawing/figure list showing the

revision letter of the drawings/figures included in the

report.

Each volume of a report is to include a quality

control sheet containing the following:

Prepared By ……………Date ……………

Checked By ……………Date ……………

Approved By ……………Date…………….

Report No. ...................Rev..............…..

Note: Authors, Checkers and Approvers are to be

defined in the Project Quality Plan, see Section 6.1.

In the case of tender documentation, which for

quality control purposed is to be considered a report,

the report number and revision are to be included on

the quality control sheet, which is to be inserted in

the copies for DA only. Copies for re-issue to other

parties such as SAB, DLO and tenderers are not to

contain the quality control sheet.

Specifics of the technical aspects for the design

works undertaken by the DA are covered in other

volumes of the QSDDM, the purpose of this section

is to define the level of detail required of the various

report stages and the general requirements for all

projects.

5.1.2 Format of Documents

The consultant is required to submit all reports,

drawings and documents in an approved format

recorded on computer media (compact disc) using

software compatible with the Client’s computer

systems.

Drawings shall be produced on AutoCAD Windows

Version 14 and submitted as .DRG files and shall

comply with Volume 6 CAD manual. All documents




should be in digital format compatible with Word 97

for Windows and the font to be used is Arial text size

11.

Reports are to be submitted in a standard format as

per the example included in Appendix 1. Tables,

graphs and charts included in reports can use colour

but this should be complemented with the use of

shading types such that when copied in black and

white the meaning remains clear. Each chart, table

etc. should be given unique reference.

Hard copy reports and documentation shall be either

comb bound with hard covers or in four-ring binder

format and accompanying drawings either up to A3

size bound or in A1 size folded and inserted in

plastic holders.

Tender drawings shall not bear the names of the

consultant or checkers/approvers. These are to be

reinstated on Contract Issue documents and

drawings as agreed with the DA.

All reports, documents and drawings to be submitted

in hard copy shall also be submitted in an

appropriate electronic format (2 copies each)

including the PDS submission.

Examples of DA submission formats are included in

the following tables:

Table 5.1.1 - Format & Numbering of Documents;

Table 5.1.2 – Design Enquiry Status;

Table 5.1.3 – Status of Available Information;

Table 5.1.4 – Investigations Status.




Table 5.1.1 – Format & Numbering of Documents

Report Format Max, Drg Size Number of Copies

Project Quality Plan A4 - 4

Sketch A4 A3 4

Preliminary A4 A1 4

Tender Documents

DA Review A4 A3 4

Roads Dept Approval A4 A3 2

Planning and Land Department Approvals A4 A3 2

Final Tender A4 A1

Documents 40

Drawings A1s 24

Drawings A3 3

Cost Estimate A4 - 4

Tender Circulars A4 A1 17

Supplementary Reports A4 A1 4

Contract Documents

Unsigned A4 - 13

Signed A4 - 5

Engineering Report A4 A1 4

PDS

Signed PSA A4 - 1

Tender Document A4 - 1

Tender Drawings - A1 1 Negative

Engineering Report A4 A1 1

Table 5.1.2 – Design Enquiry Status

Service Authority Date Submitted Date of Reply Information Received Action Required

Table 5.1.3 – Status of Available Information

Required Information Source Date of Receipt Information Abstracted Action Required




Table 5.1.4 – Investigations Status

Investigation Ministry/ Consultant

Appointment

Name of Sub-

Consultant/

Contractor

Programmed Start Duration Status

Further examples are included in Appendix 1. These are:

• Example of report summary page, together with header and footer;

• Example of calculation cover sheet;

• Typical calculation sheet for foul sewer sizing;

An example of a project programme is included in Appendix 2.

Typical drawings are shown in Appendix 3.




5.2 Sketch Stage

The requirements for the sketch stage report are

given in section 10.1 of the Professional Service


1984xv as amended and amplified by the particular

terms of reference in the project PSA. The main

objective of the report is to define the design

parameters, prepare various design options and

recommend the preferred option. The main part of

this design stage is the collection and assimilation of

the information required for the design, the control

and use of which of forms an important part of the

sketch stage report.

The DA requires the following basic structure, which

is to be amplified, if required by the project PSA.

5.2.1 Structure/Content of Report

Objective of the Project

A clear statement of the objective of the project is to

be given with specific reference to the main design

criteria.

Methodology and Work Plan

The purpose of the methodology and work plan is to

define how the objectives of the PSA will be

achieved and cover the following subjects:

• staff – approval of appropriate staff will be

covered by the Project Quality Plan, see

Section 6.1, the purpose of this section is to

define the specific input from the various

members of the design team. It should be

clearly stated whether design works are to

be carried out in the consultant’s offices,

outside Qatar or by a sub-consultant;

• investigations – each project will require

specific investigations to be carried out, the

details pertaining to which are covered by

Section 3 of this Volume. The methodology

and work plan should state the investigation

to be undertaken, the company who will

undertake the work, description of the

investigation and the information that is to be

obtained. Whether a specialist investigation

company is to be employed directly by the

Government, or the consultant, should be

noted;

• data required – data will be obtained from

numerous sources depending on the project

requirements which should be defined at this

stage and is presented in tabular form as

shown in Table 5.2.1 below.

Table 5.2.1 – Data Requirements

Data Required

Source Date Requested

Date Received

Remarks

• studies – each specific project will require certain studies to be carried out. These will

be defined in the PSA but should be listed

and briefly described in the methodology

and work plan. These should be tabulated to

enable progress tracking to be carried out,

see Table 5.2.2 below.

Table 5.2.2 – Study Progress

Study

Date

Required

Date

Submitted

Date

Approved Remarks

Note that these studies may be submitted

separately or be included in a design stage

report. Studies submitted separately should

follow the same quality control procedures

for reports.

• design calculations – at the methodology

and work plan stage the design calculations

required for the project should be identified

and itemised. With the studies, a reporting

table should be included. Note, these

calculations may be submitted separately or

be included in a design stage report. All

calculations, whether included in a report or




submitted separately are to have a cover

sheet in the format shown in Appendix 1.

• deliverables schedule – in addition to the

design calculation and studies a full table of

all deliverables is to be included.

5.2.2 Programme

The project programme submitted within the Project

Quality Plan is to be up-dated to show current

progress, as per the example shown in Appendix 1.

5.2.3 Design Enquiry Status

Design enquires will have been submitted to all

authorities as detailed in Section 4.1, the sketch

stage report is to contain a table, showing the status

of information received and any action required to

facilitate the receipt of outstanding information.

5.2.4 Available Information

Most design projects will have a relationship to other

design works that could vary from master planning

to detailed design or construction. The consultant

will be required to research all available design data

and existing assets that DA may have. This

research should extend to other departments, and

authorities and should not be limited to the

information received in response to design enquires.

It is the consultant’s responsibility to ensure that all

the required information is obtained and assess the

accuracy of information received. The sketch stage

report should identify the required information

available and report the status of this information

and any further action required, clearly tabulated,

and including a synopsis of all relevant data.

5.2.5 Investigations

The investigations required will have been identified

in the methodology and work plan. Programming of

the investigation may require them to have

commenced prior to the submission of the sketch

stage report. The status along with other basic

information should be reported clearly in tabular

format.

5.2.6 Land Use

Land use is of the utmost importance and is

fundamental information for any scheme as it

governs the end use of the scheme and indicates

area where new facilities can be constructed. The

land use can be obtained from the Lands/Planning

Department and should be reproduced in the report

as per sample drawing, C415/ER002, shown in

Appendix 3.

5.2.7 Design Criteria

The technical aspects of the design criteria to be

adopted on different types of schemes are detailed

in the appropriate sections of this manual. However,

the sketch report should clearly state the design

criteria that are to be used on the project.

5.2.8 Options

At sketch stage design, the requisite design options

need to prepared and presented in sufficient detail

so that the merit and demerits of each option can be

quantified and assessed and estimates for the total

cost of each option prepared.

5.2.9 Recommendation

Based on the merits, demerits and cost estimates

for the individual options, the consultant shall make

a recommendation as to which option is to be

adopted clearly stating how this conclusion is

reached.

5.2.10 Appendices

Appendices can be used as necessary to included

information, such as design calculations, that are too

bulky for in incorporation in the main text, but as a

minimum the following two appendices should be

included:

• Project Brief;

• Relevant Correspondence and Minutes of

Meetings.




5.2.11 Typical Drawings

As noted above, one of the main objectives of this

manual is to set the level of information required at

each design report stage. In this respect, the

following example drawings have been included in

Appendix 3:

Sewage EIC0543/D3/FS/100

Surface Water EIC0543/D1/PR/SW/100

Sewage Treatment Works C627 004

Process Flow Diagram C627 011

Land Use C415/ ER002

5.3 Preliminary Stage Report

The requirements for the preliminary stage report

are given in Section 10.3 of the Professional Service


1984xv as amended and amplified by the particular

terms of reference for the project. The main

objective of the report is to fix the design. The

finalised scope, depending on the project specifics,

will comprise drawings showing:

• Layout plans;

• Long sections of pipelines;

• Structural drawings;

• Compound layouts;

• Mechanical and electrical installations.

The DA require the following basic structure, which

is to be amplified if required by the project PSA.

5.3.1 Structure/Content of Report

Programme

The programme submitted with sketch stage and

intervening progress reports should be updated and

any revisions to the deliverable schedule included.

Design Enquiry Status

A table should now be complete with all information

received. If it has been the case that some

information has not been forthcoming then the report

should clearly state any assumption made in the

absence of this information.

Available in formation

As with the Design Enquiries, this should be

complete and in the absence of information

assumptions made clearly stated. The preliminary

report is to identify which sources of information

have been used and specific information abstracted.

Investigations

Investigations should have been completed and the

details recorded in tabular format.

Design Criteria

The final design criteria used to determine the

design should be stated and any revisions from

sketch stage highlighted.

Cost Estimates

The cost estimate should be updated to match the

level of design completed.

Appendices

Appendices can be used as necessary to include

information, such as design calculations, that are too

bulky for in incorporation in the main text, but as

minimum, the following four appendices should be

included:

• Project Brief;

• Relevant Correspondence and Minutes of

Meetings;

• Drawings;

• Details of Cost Estimate.

Typical drawings

Sewerage, SW, STW, and TSE drawings as

necessary, in sufficient detail to clearly illustrate the

design options discussed.




5.4 Detail Design and Tendering Stage

Detailed design is to be prepared and presented in

the form of tender documentation. This may be for a

single, or for several contracts depending on the

requirements of the PSA. The tender documentation

will be divided in to the following sections:

• Drawings;

• Specification;


The tender documents will be prepared in

accordance with section 5.5. On completion, they

will be submitted to the DA for review and

comment/approval. Following approval by the DA,

final approval will be required from the Roads Affairs

and the Lands and Planning Department prior to

submitting for SAB and DLO approval.

A cost estimate, in the form of a priced bill of

quantities is to be submitted with the tender

documentation.

Prior to progressing to tender stage any building

permit required should be completed.

5.5 Documentation

As noted above, the tender documentation will

comprise the following.

5.5.1 Drawings

All drawings are to be prepared in accordance with

Volume 6- CAD Manual, and should fully describe

the works to be constructed.

5.5.2 Specification

The specification will be combined with the

necessary other sections to form the main tender

document, this will, for civil works, comprise a single

volume but where electromechanical works are

required a separate volume containing the

Mechanical and Electrical specification will be

included.

The main tender document will comprise the

following sections:

• Form of Tender;


• Conditions of Contract;

• Project Specification;

• List of Drawings;


Instructions to Tenderers

Instruction to tenderers are to a standard format,

however, the consultant will be required to

incorporate the:

• Project Title, Number and Code;

• Budget Reference and Code.

Conditions of Contract

The Conditions of Contract are to be the General

Conditions of Contract prepared by the Ministry of

Public Works. This will be amended by the Part II

Conditions of Particular Application, which are

standard on all contracts and only require the

incorporation of the:

• Project Title, Number and Code;

• Budget Reference and Code.

The Specimen Form of Contract Agreement is to

included in both English and Arabic and as such be

updated to represent the correct Government

signatories at the time of preparation.

Project Specification

The project specification will comprise the general

specification and project specification, which may

also include a Mechanical and Electrical

Specification depending on the project

requirements.

The general specification is to be the Qatar National

Building Specification or Qatar Construction

Specification as specified by the DA for each

project. Drainage Affairs issue specification

amendments and those issued at the time of

preparation are to be included. Other amendments

to the general specification for items such as the

Engineer’s site accommodation will be incorporated

to suit the project requirements.




The project specification will contain all the

necessary specification required for the specific

project and are written for each project.

Where a mechanical and electrical specification is

required this should follow the same format as

above. In the case where QNBS is adopted this will

be a full specification as QNBS does not contain a

mechanical and electrical specification.

List of Drawings

The project specification is to contain a complete list

of all the drawings that comprise the contract. This

list shall contain the following information:

• Drawing Number;

• Drawing Title;

• Drawing Revision.

5.5.3 Bill of Quantities

The Bill of Quantities is to be prepared in

accordance with the Civil Engineering Method of

Measurement, 3rd Edition (1991) with additions and

amendments as detailed in the DAs standard

preamble, if applicable.

5.6 Engineering Report

The Engineering Report shall be prepared for the

Works included in the detailed design, details of

options not adopted need not be included. The

report is to contain a summary of the main elements,

which will depend on the particular project, typically:

• design criteria;

• design parameters;

• hydraulic calculations;

• effluent standards;

• average and peak design flows (STW’s);

• general layout plans;

• process flow schematic;

• hydraulic profiles;

• calculations for rising mains with pump

system curves.

A summary of all the reports prepared for the

scheme shall be given.

A separate section of the Engineering Report, if

required, shall deal with the design of

electromechanical equipment. It shall include a

summary of design criteria for all principal

equipment such as pumps, process units, aerators,

compressors, air conditioning, ventilation and odour

control systems, specifying respective electrical

loads and estimated power consumption. The

calculations shall be accompanied by a single line

diagram and complete electrical load chart showing

principal parameters for confirming the capacity of

transformers, power supply, capacity of standby

generators detailing kVA and kW loads.

The Engineering Report is to include the following

aspects, to particular project requirements, and be

prepared in accordance with the format and quality

control procedures detailed in this section.

Plans: Layout of the Works including existing

Works and those which are under construction at a

suitable scale showing general arrangement of

pumping stations, chambers, manholes, structures,

other facilitates, buildings, roads, pipelines and

works inter-faces etc.

Catchment and sub-catchment plans showing the

main drainage routes and major facilities are to be

included at an appropriate scale.

Plan drawings showing general arrangements with

dimensions of pipelines, buildings, structures,

chambers and manholes. The drawings are to

illustrate all M&E equipment with centre lines and

leading dimensions; machinery pipelines, cable

ducts, control panel, valves, penstocks etc.

Sections: Sections of all pipelines and other

hydraulic structures, at appropriate scales. These

are to include chainages, connecting pipelines and

structures, manholes/chambers, invert cover and

ground levels, bedding type, pipeline diameters and

materials, gradient, terrain crossed, major service

crossings and any specialist construction

requirements.

Detailed Drawings: Outline drawings, to

approved scales, of: building, structures pumping

stations, chambers, manholes, roads, pipelines and

including M&E equipment showing the principal




components, pipework, fuel tanks etc. The limit and

extent of the Works undertaken under the Project

shall be clearly identified together with existing and

other proposed works.

Hydraulic Model Studies: Description and

illustration of the hydraulic model study for relevant

catchment and sub-catchment areas. The study is to

cover current and fully developed catchment

conditions. The report is to show hydraulic profiles

for peak flow along all pipelines, hydraulic

structures, chambers, pumping stations, together

with clear illustrations and listings of all input data.

M&E Equipment: Schedule of all items of M&E

equipment and instrumentation control and

automation (ICA). Where the new equipment is

incorporated with existing equipment, details shall

also show existing machinery and apparatus. A

basic P&I diagram indicating the method of control

and layout of the proposed instrumentation. The

diagram shall incorporate existing equipment where

necessary to illustrate the complete system.

Hydraulic Calculations: Complete manual

hydraulic calculations shall be provided where not

provided by computer model or spreadsheet.

Structural Design: Structural calculations shall

be prepared for the structural elements of the

scheme.

Geotechnical Information: A summary of

geotechnical information and key parameters used

in the design of the Works together with a drawing

showing the location of relevant boreholes and test

pits.

Health and Safety: The Report shall contain a

summary of health and safety measures adopted to

meet fundamental safety requirements with respect

to construction, refurbishment, operation and

maintenance of those sections of the Works which

are covered under this PSA.

Environmental Impact Statement: The report

shall contain an EIS if requested by in the PSA

(refer to Section 3.7).

5.7 Supplementary Reports

Supplementary Reports will be required by the

specific project brief and will cover such items as

specialist investigations. These are to be prepared

and submitted in accordance the quality control and

format requirement details in this section.




6 Checking Systems

6.1 Project Quality Plan

The objective of the Project Quality Plan is to

demonstrate that the consultant has a full

understanding of the project and Drainage Affairs‘s

requirements and should as a minimum comprise

the following sections:

• Project Description;

• Work Plan;

• Schedule of Deliverables;

• Investigations and Sub-Contracts;

• Quality Requirements;

• Meetings;

• References and Sources of Information;

• Team Structure;

• Programme.

The Quality Plan is to be submitted within two weeks

of the commencement of the project unless

otherwise specified in the project brief.

Project Description: The Project Description is to

define the scope of the works as defined in the PSA.

It is to expand on the brief to fully define the

project’s requirements and DA’s aspirations.

Work Plan: In this section the consultant is to

describe how the project will be carried out. The

design approach, i.e. the individual design elements,

are to be stated and the method by which these will

be undertaken. The design philosophy, i.e. how the

consultant will utilise his resources to complete the

work, is to be described with particular reference to

internal and external communications.

A methodology is to be included stating the

requirements at different design stages, the

information required form external sources, and the

process by which the major design parameters will

be derived.

Schedule of Deliverables: A schedule listing all the

project deliverables and delivery dates is to be

included.

Investigations and Sub-Contracts: Where

specialist investigation and sub-contract works are

to be carried out, these shall be listed with the name

and full details of the proposed specialists included

for DA approval.

Quality Requirements: The minimum requirements

are stated in Section 5. The purpose of this part is

for the consultant to demonstrate how he will

meaningfully fulfil these requirements, with

reference to his own company quality control

procedures. The names of authors, approvers and

checkers must be clearly stated.

Meetings: Progress meetings are to be held and

should be held to coincide with the monthly progress

reports. Other meetings will be required on subjects

such as:

• Project start-up (Kick off);

• Co-ordination with DA Divisions;

• Co-ordination with other consultants;

• Co-ordination with other Departments;

• Design stage reviews.

This will vary depending on the project

requirements, but all meetings should be identified

and listed in the Project Quality Plan along with

provision dates to suit the design programme.

References and Sources of Information: Section

5 describes the sources of information and

references. The sources of required information

should be identified and listed in the Project Quality

Plan.

Team Structure: Organograms showing the team

structure of the DA and consultant’s staff are to be

included, along with contact details as appropriate.

The consultant is to include a curriculum vitae, and

any other relevant documentation, for all his

proposed staff for DA approval.

Programme: A programme, in an approved format,

using appropriate software such MS Project or

Primavera is to be included. This should show all the

main design stages and activities in sufficient

details. to allow approval by DA. The programme

should be in a format that will allow progress to be

monitored and up-dates to be issued as required.




6.2 Stage Approvals

Approval of the DA will be required for the main

design stages namely:

• Sketch Stage;

• Preliminary;

• Detailed/Tender;

• Engineering Report.

Although the project PSA may vary or be expanded

on, the above the implications of approval of the

report will be as follows.

Sketch Stage: The recommended option has been

accepted and can be progressed to preliminary

design.

Preliminary: The design and scope of work is fixed

and detailed design and tender documents can be

produced.

Detailed/Tender: Tender documentation is finalised

and necessary copies of documents can be

produced for tendering purposes.

Engineering Report: The engineering and design

elements are finished and the project is effectively

complete. The only remaining obligations will relate

to the tendering process and may included items

such production of tender documents, tender review

and production of contract documentation.

6.3 References and Information updating

During the course of the project the consultant will,

from various sources, obtain much information. The

sources of this, details of information received, and

details utilised will be included in the various design

stage reports as described in Section 5. It is not

generally desirable or practicable to include copies

of the actual information in the reports. However, the

consultant is to maintain a register of all information

received and store this information in such a way

that in can be easily retrieved for the duration of the

project. The DA may request an inspection of the

register and storage arrangements at any time

during the course of the project and this is to be

accommodated by the consultant.

6.4 Progress Reporting

The consultant is to submit a Monthly Report to an

approved format and this should contain the

following:

Project Details

• Project Title;

• Project Code;

• Consultant Name and Contact Details;

• Report Title;

• Month Reported on;

• Report Issue Number;

• Prepared By;

• Approved By;

• Project Co-ordinator;

• Consultant Key Staff;

• Start Date;

• Completion Date;

• Addends issued.

Introduction

• Brief statement of the scope of the project.

Progress Summary

• List of report issued;

• Main objectives received;

• Status of on-going works.

Detailed Progress

• Details of work undertaken in the month;

• Details of information received.

Outstanding Information

• Details of information that is still required.

Key Issues

• Main item of progress;

• Any items of importance.

Programme and Planned Process




• Status report of actual progress compared

with original programme;

• The project programme is to be updated and

submitted in tracking format.

Schedule of Meetings Held and Site Visits

Undertaken

Schedule of Submission

• Programmed dates;

• Actual dates;

• Data Collection;

• Status report of data collection;

• Staffing;

• Details of consultant’s staff who worked on

the project.

Variations

• List of finalised variations;

• List of variations being processed;

• List of variations notified by consultant.

Delays

• List of accepted delays;

• List of delays notified by the consultant.

Addenda

• List of finalised addenda;

• List of addenda being processed.

Finance

• List of invoices submitted and payment

status.

Health and Safety

• Description of any health and safety issues

applicable to the project.




7 Operation and Maintenance

7.1 Normal Operations

7.1.1 Operational Objectives and Priorities

The overall objective of the Department shall be the

provision, within budget, of timely, efficient and

effective operational and maintenance services,

including scheduled preventative maintenance and

unscheduled corrective activities. This overall

objective seeks to:

• Maximise the overall performance of all

infrastructure;

• Increase performance levels by the use of

improved technologies and methods;

• Perform services to the best industrial

practices in terms of delivery, efficiency,

workmanship, housekeeping, planning and

control;

• Cater for expansion of the wastewater

collection, treatment and disposal systems

to meet future demands and deliver its

required levels and quality of service;

• Monitor and control operations and

maintenance expenditure within agreed

financial targets;

• Provide the continuity of the services with

minimal disruption to the flows and pumping

requirements;

• Guidelines for Setting up the Operating

Procedures.

The operating procedures shall address the

following particular requirements:

• Operations shall be structured using a split

system, i.e. 24 hrs;

• Ensure that no activity causes hindrance to

the execution of any works and fully

cooperate with the concerned parties;

• Operate/adjust pumping station reservoirs,

networks and or treatment works to

accommodate varying demand requirements

depending on the weather, maintenance

programme, upstream/downstream flow

conditions, etc.;

• Confine all operations, maintenance and site

establishment facilities to within the site

boundaries;

• Safeguard all structures in the vicinity of the

site;

• Ascertain from the public utility authorities,

positions of all existing underground

services and maintain, protect or divert them

as required;

• Establish procedures for procurement and

installation of all spare parts, consumables

etc.;

• Establish and maintain a central

computerised stores management system;

establish minimum stock holding; replenish

stock in a timely manner; and as and when

necessary, man stores to suit operational

requirements;

• Ensure all personnel are fully familiarised

with the requirements of the services to be

provided and the various site layouts, plant

assets, site safety regulations, statutory

requirements and Department procedures;

• Implement a community relations

programme to prevent abnormal and

improper use of assets;

• Emergency response service;

• Develop ongoing planned

repair/refurbishment work;

• Establish proactive planned inspection,

operations and maintenance, and cleaning

routines;

• Undertake reactive and non-routine

maintenance;

• Provide appropriate qualified personnel to

plan, direct and supervise all activities.




7.1.2 Management and Control of Operations

A co-ordinated and planned operations policy shall

be adopted with the aim of providing a cost effective

service whilst providing ongoing security of service

and assurance as to the operation of the asset.

Base operation management on sound planning,

good communications and good working

relationships between all parties concerned.

Optimise the operation of the system with the help of

accurate operational records and management

science.

Consider personnel safety in all operations.

Organise the different levels of operation procedures

into the following:

• Routine operation procedures which are

normally carried out without shutting down of

plant. These include operational data

gathering, plant condition monitoring,

pump/equipment status, cleaning etc.;

• Routine operational procedures requiring

shutting down of plant for not more than

two hours continuously and where a standby

facility is available;

• Major maintenance/inspection and overhaul

procedures which require shutdown of the

plant for more than two hours irrespective of

availability of standby plant;

• Routine maintenance procedures requiring

shutting down of plant for not more than two

hours continuously and where a standby

facility is available;

• Emergency procedures which require

immediate action.

Apply all Health and Safety requirements and in

particular for confined spaces, traffic management,

use and storage of chemicals and such substances,

workshop and offices.

Optimisation of Pumping Station Operation to

maximise the life of ‘whole system’ assets and

minimise station and network maintenance. The key

to optimising operational activities of assets is an

effective schedule and dispatch system backed up

by good logistics management. Ongoing analysis of

the database generated through Computerised

Maintenance Management System (CMMS) linked

to the assets will enable improvements and fine

tuning of the operational activities, maximising asset

life, minimising costs of delivery and ensuring

activities are effective.

Regulation of flows using Pumping Stations,

Valves, Penstocks, Temporary Stoppers, etc. to

Accommodate Work on the System: Operation

and maintenance of assets, e.g. networks, pumping

stations and treatment works, are closely interlinked

and have a close working relationship. Interface and

co-ordination with other authorities, contractors, etc.

is essential if the total service delivery of the system

is to be maintained.

Adjust normal method of working/operational

practices/maintenance programme to accommodate

changes in up/downstream flow conditions resulting

from work by others.

Surveillance of Networks to Ensure Appropriate

Use and/or Stop Misuse: Any environment in

which explosive or poisonous gases are present,

presents a potential safety hazard. Therefore,

permission from the Department and other

authorities shall be sought for works falling under

the following categories:

• Dewatering discharge;

• Entering into confined space, e.g. manholes,

chambers, pump station wet-wells, etc.;

• Discharge of waste, e.g. hazardous or toxic

material, oil, collected sediments, fat/grease,

rags, etc.;

• Monitoring salinity;

• Illicit and/or cross-connections.

The Department shall monitor the assets through

various sources in order to ensure their proper use.

Co-ordination of Work on the System by Others

(Connections, Rehabilitation, Diversion, etc.):

Co-ordination of work with others is essential to

effectively manage the ongoing operations of the

network.

Ensure that no activity causes hindrance to the

execution of any work on the system. Adjust normal




method of working/operational practice/maintenance

programmes to accommodate changes in

up/downstream flow conditions resulting from work

by others or as required.

7.1.3 Operating Procedures, Schedules and Organisation

Operating procedures shall be in accordance with

the following:

• Equipment manufacturer’s

recommendations;

• Operating requirements;

• Industry standards.

Operating procedures shall be written in accordance

with relevant ‘best practice standards’ to achieve

best possible quality. These will concern facilities,

quality of service, staff and their organisation.

Operating procedures shall be followed by all staff.

Operating procedures shall be reviewed and audited

systematically and regularly to ensure that they are

practical, safe and meet the intent for which they are

designed.

Operating schedules shall:

• Generate work order schedules based on

resource levelling techniques;

• Graphically analyse and manipulate

availability of resources;

• Set down-time requirements for machinery

required to be off-line prior to work being

performed;

• Optimise asset life through what-if analysis;

• Store new schedule dates for comparison

with the original target dates;

• Forecast future preventive maintenance

dates for resource planning.

The operation of the Department’s assets will be

organised into manageable; efficient areas of

responsibility and service centres for call-outs,

inspections, cleaning and repairs.

7.1.4 Cost Control and Operational Efficiency

Achieve the following:

• Optimum control of resources;

• Best cost management and auditability;

• Ability to schedule complex, fast-moving

work loads;

• Optimum performance of the assets;

• Planned maintenance on programme;

• Response to emergencies and complaints

within agreed response time.

The key to optimising operational activities is an

effective schedule and dispatch system backed up

with good logistics management in delivering

essential services to the people.

Ongoing analysis of the database generated through

CMMS linked to the assets will enable

improvements and fine tuning of the

operational activities, minimising costs of delivery

and ensuring activities are effective. Analysis of

trends in salinity, odour issues, collapses, and

blockages against asset class, operating context,

location and history will allow problems to be

identified and addressed effectively. Analysing the

performance of assets will enable understanding of

assets performance and determine the most

appropriate operational and maintenance strategies.

7.2 Routine (Scheduled) Maintenance

A routine (scheduled) programme shall be

implemented over a period of time to improve the

utilisation of the assets, reduce down-time due to

failure and therefore corrective maintenance costs.

The approach to maintenance of assets should be

based on the following philosophy:

• Retain the functionality of the assets in

accordance with the performance

requirements of the Department;

• Minimise the impact on public health;




• Customer and environmental consequences

of asset failure are avoided or minimised;

• Maintenance programmes take account of

all aspects of business effectiveness, risk,

safety, environmental integrity, energy

efficiency, product quality asset life

expectancy and customer service;

• Maintenance strategies are based on a

proper understanding of the life performance

of the assets in their operating context, and

maintenance tasks reflect both technical

feasibility and cost effectiveness;

• Condition-based maintenance tasks will be

preferred and will be based on the ‘lead time

to failure’, not availability or reliability;

• Ensure that protective devices are effectively

maintained, thus limiting the probability of

multiple failures at acceptable levels;

• Ensure an appropriate balance between

maintenance and capital solutions, i.e. cost

effectiveness, asset capability vs. current

and future required demand.

Maintenance programmes based on the above

principles will ensure that lowest ‘whole of life’ costs

will be achieved in delivering the required asset

performance. Maintenance programmes may be

controlled through CMMS that generate work orders

on a regular basis (i.e. daily, weekly, etc). This

system allows the control of corrective maintenance

and stock management, and produces reports.

7.2.1 Definition of Scheduled Maintenance

Scheduled maintenance shall include: periodic

lubrication, inspection and testing, based on the

recommendations of the equipment manufacturer. It

shall also take account of any specific legal

requirements relating to particular work equipment,

e.g. inspection and testing of lifting gear.

A Scheduled Maintenance programme shall consist

of the following aspects:

• Routine Maintenance;

• Routine Inspections;

• Monthly Inspections;

• Annual Inspections.

7.2.2 Classification of Routine Maintenance Tasks

Routine maintenance tasks will be divided up on the

basis of frequency and will bear the effective

operational date during the year. There will be for

example routine daily, weekly, monthly, quarterly,

six-monthly, annual and two-year operations etc.

Particular attention will be paid in planning

procedures to avoid an excessive concentration of

programmed works on the same day. The following

are some typical examples of routine maintenance:

• Extensive manual rodding programmes;

• Routine maintenance using mechanical

rodding equipment e.g. combi-jet rodding,

mechanically driven cutters, screen

cleaning, bucket machines;

• Manhole/chamber inspection and renovation

programmes;

• Manhole/chamber location, raising and

lowering;

• Construction of manholes, discharge

manholes and overflow structures;

• Treatment of odour with absorbent chemical

products;

• Blockage removal;

• Pressure main inspection and repair;

• Sewer excavation and repair;

• Joint sealing programmes (patches, sleeves,

etc.);

• Chemical grouting programmes;

• Inspections with CCTV, probes and flexible

probes;

• Man-entry inspection programmes;

• Routine maintenance for valves, probes and

flowmeters (lubrication, painting, electric

wiring inspection, etc.);

• Ordinary maintenance of control, indicators

and measurement instrumentation;

• Electrical and Mechanical test procedures;




• Mandatory/statutory testing of equipment;

• Maintenance of traffic management

equipment;

• Maintenance of safety equipment; gas

monitors, man-lifts, harnesses, etc.

Safe working methods, e.g. working in confined

spaces; isolation, tests and restoration on high

voltage equipment; isolation, working and re-starting

of rotating & electrical equipment; winching;

jetting/de-silting of sewers; major/minor pipe repairs,

and working in public highways.

Cleaning of pipes, tanks, sumps: Cleaning

services are defined as the removal from the

networks, tanks, sumps, etc. of: obstructions,

deposits and debris. Cleaning services can be low

or high velocity jetting, flushing, winching, cutting

and rodding.

Preventive/Reactive maintenance of assets;

pumps, motors, starters, manholes, valves, air-

conditioning units, buildings, civil structures

and etc: A well planned and executed

preventive/reactive maintenance programme is

absolutely necessary in order for pumps,

motors, starters, valves, air conditioning and civil

structures to operate efficiently. Attention to

maintenance is particularly important in preventing

the accelerated corrosion and wear resulting from

the severe conditions imposed by acidity, gases and

dampness.

Establishment of and a firm commitment to a strong

scheduled maintenance programme are critical to

reduce equipment downtime and extended

equipment life.

Maintenance of pump sets, MCCs, ACs, etc.: A

continuing preventive maintenance programme can

maximise the performance, minimise life cycle

operating costs, and extend the life of assets such

as pumps, MCCs, ACs, etc. by several years.

Keeping an accurate record of the performed

maintenance will also help in the diagnosis of

failures when they do occur.

7.2.3 Method Statements on Each Activity and Sub-Activity

All major activities carried out on-site shall be

preceded by the creation of a method statement.

Typical examples of method statements are detailed

below:

• Safety/risk assessments;

• Isolations required;

• Work procedure;

• Permits required;

• Emergency procedure;

• Personnel required;

• Tools required.

The Department shall require that any organisation

undertaking to perform work on assets under its

jurisdiction shall submit appropriate method

statements for implementing the proposed work.

7.2.4 Organisation and Control of Scheduled Maintenance

Efficient maintenance schedules for any asset

require that inspection precede maintenance

activities. There are many drivers of asset

performance, and predicting asset condition and

therefore maintenance requirements are very

unreliable.

By identifying key points that can provide

representative statements on the asset condition,

planned maintenance activities can either proceed

or be deferred. The programme cycles are

correspondingly adjusted to reflect the new

information. If maintenance activities show the rate

of deterioration of the assets to be greater than

predicted, the inspection cycle is shortened to suit.

In some instances, inspections are required to

simply provide ongoing monitoring of the rate of

deterioration of assets, to enable planning of capital

expenditure in major renovation programmes. It is

essential to schedule asset inspections to identify

problems or issues, assess rates of deterioration

and to calibrate planned maintenance activities.

These inspections will be scheduled through

Computerised Maintenance Management System




(CMMS) and dispatched to the inspection team to

action.

7.2.5 Inspection, Quality Control and Follow-Up

The inspection programme will be based on the best

asset data available:

• Existing documents and drawings;

• Asset details;

• Existing asset condition data;

• Asset historical data;

• Local knowledge of existing employees;

• Most appropriate asset evaluation

methodology;

• Evaluation rate for the specific asset.

During routine maintenance and inspection,

maintenance personnel will note the condition of

various assets and identify areas that need repair.

Potential problems documented and repair work

prioritised, depending on the nature and severity of

the problem:

• Immediate repair, e.g. pump station failure,

sewer line rupture, sewer line blockage.

These repairs may be temporary until

scheduled or capital improvements can be

completed;

• Scheduled repair, e.g. lubricating pump

motors, sealing cracks, flushing sewer lines,

repairing manholes, etc.;

• Capital improvements, e.g. rehabilitating

sewer lines, constructing or replacing new

pump stations, installing new sewer lines,

etc.

Quality controls will be done by maintenance

personnel through inspecting installations to check

for any breakdowns, defects, or other elements

interfering with asset operations. In any case these

controls make it possible to notify any critical

situation to the management for further action.

The work of the operators assigned to the asset

maintenance/installations will be checked by these

inspections as well as service quality in general,

particularly related to the following:

• Reliability of collected data;

• Condition of works and equipment;

• Compliance to instructions and manual

procedures;

• Accuracy of measures taken;

• Service management efficiency;

• Presence of abnormal conditions.

The department shall ensure that all work complies

with the requirements of the relevant QC/QA

standards, as a minimum. Internal audits shall be

performed to verify that QC/QA procedures are

adhered to.

A review and follow-up system will also address the

problems and failures with assets, e.g. why a failure

occurred, and to ensure that there is no repeat. Any

failure discovered through the exercises shall be

managed through the QA corrective action system.

Implementation of actions shall be followed up by

means of continuous monitoring, planned reporting

back on actions or direct follow-up. The result of the

follow-up shall be documented.

7.2.6 Maintenance and Inspection of Safety/Rescue Equipment

The condition of the safety and rescue equipment

shall be monitored during routine site visits by

operations staff. When a safety/rescue item is

issued from the stores it will be accompanied by

instructions for its use, storage and maintenance.

Inspection and operational checks must be carried

out before and after each use:

• Seek advice from the manufacturer if in

doubt or if any faults or defects are found

with a unit;

• Inspect for: loose bolts, bent or damaged

parts, signs of corrosion and ensure fully

legible labels and instructions are present;

• Examine the housing for wear, cuts,

damage, distortion, fractures or other

damage;




• Gas detectors to be calibrated by qualified

personnel, as required;

• Operate the mechanism and confirm the

device activates correctly;

• Remove from service and return to

authorised dealer for service;

• Document the inspection in the inspection

log.

7.3 Non-Scheduled (Non-Routine) Maintenance

Non-scheduled maintenance is a result of a defect

developing and/or being identified between

scheduled maintenance. Non-scheduled

maintenance will:

• Provide immediate attention to the problem;

• Stabilise the situation and either provide

temporary repair or provide full correction of

the defect.

7.3.1 Definition of Non-Scheduled Maintenance

Non-scheduled maintenance activities are defined

as any activity, which is required to sustain the

proper and continued operation of any system, but

are not at the time included in the Computerised

Maintenance Management System (CMMS).

7.3.2 Classification of Non-Scheduled Maintenance Tasks

The Department shall identify and classify all non-

scheduled maintenance activities and where

applicable include them in the Computerised

Maintenance Management System (CMMS). Non-

scheduled maintenance tasks can be divided up on

the basis of priority.

7.3.3 Identifying the Need for Non-Scheduled Maintenance

During routine maintenance and inspection, crews

may identify potential problems. These should be

documented and reported to the management for

prioritisation and co-ordination of repair work. There

are three general priorities that may be used:

• Immediate repair – urgent problem that may

cause an immediate overflow, e.g. pump

station failures, sewer line collapse,

blockages, etc.;

• Scheduled repair – problems that do not

require immediate action, e.g. sealing

cracks, repairing manholes, lubricating

pump motors and flushing sewer lines;

• Capital improvement - for large projects or

replacement project, e.g. rehabilitating

sewer lines, constructing or replacing a new

pump station.

7.3.4 Management of Non-Scheduled Maintenance

Non-scheduled (reactive) maintenance is geared to

assessing and resolving system component

breakdowns as quickly and as efficiently as

possible. Examples of such problems are as follows:

• Blockages in sewers due to encrustations;

• Blockages in sewers due to root in-growths;

• Blocked storm drains;

• Wastewater overflows;

• Bursts on sewage pumping mains;

• Leaks and bursts on irrigation mains.

Procedures should be put in place so that staff can

react to the failure of major items, or have clear

ideas on contingency actions. Priorities can be

made as follows:

• Quick assessment of problem – can it be

resolved?

• Safeguard process – deduce any impact on

environment and community;

• Detailed inspection – formulate plan of

action;

• Mobilise resources – personnel and

materials;

• Fix problem;




• Report on problem and ways to prevent

recurrence in future.

7.3.5 Control of Costs and Quality

The Department shall have in place management

and accounting systems that would allow it to set

budgets for the works, manage the costs and

measure actual performance against budget for cost

categories such as labour, spares, consumables,

fuel, recruitment costs, capital items, chlorine, and

repairs.

7.3.6 Inspection and Follow-Up

Maintenance personnel shall inspect installations to

check for any breakdowns, defects or other

elements interfering with asset operations. In any

case, these controls make it possible to notify any

critical situation to the management for further

action.

The follow-up system shall address the problems

and failures with assets, e.g. why a failure occurred,

and to ensure that there is no repeat. Any failure

discovered through the exercises shall be managed

through the QA corrective action system.

Implementation of actions shall be followed up by

means of continuous monitoring, planned reporting

back on actions, or direct follow-up. The result of the

follow-up shall be documented.

7.4 Emergency Procedures

This guidance document provides advice on

emergency response planning. It aims to help

operators consider the appropriate level of detail for

a specific site, taking into account the risks and the

site layout.

Emergency procedures will define the scope of

activities covered, staff responsibilities, and

procedures for dealing with a variety of events. The

level of response will depend on health and safety

issues, staff training, the level of Personal Protective

Equipment (PPE) available, the nature of the

problem, and types of control equipment available

on the site. The appropriate level of response will,

therefore be site specific. It is important to consider

what could happen in the worst case and to take this

into account in developing the procedure. A check

list of actions may be a useful addition.

A well prepared plan should give competent

operatives adequate information to initiate

appropriate remedial action. This will eliminate

having to wait for decisions to be made by others

and reduce the overall response times required to

contain the incident.

A well-prepared plan will also include availability of

resources, internally and externally.

7.4.1 Definition and Classification of Emergencies

An incident can be defined according to the alarm

levels that trigger an emergency response:

Level 1 – incidents arising on a daily basis, e.g. a

blockage or surcharge imminent or occurring. After

intervention and action by the operator, the situation

returns to normal with no resultant effect on the

system. This type of emergency does not require

other organisations to be notified immediately.

However, a procedure will exist to record the

incident in order to allow recognition that these

problems can exist.

Level 2 – incidents limited to a well defined area

that completely halt the operation of that area, e.g. a

pipeline collapse. Level 2 incidents concern well

defined zones of the system and during these

incidents the affected zone is non-operational.

Irrespective of the severity of the situation, the

operator in charge of the problem will provide an

account as soon as possible to the management.

Following internal communications, the

management will implement the necessary

safeguards. These may involve:

• co-ordinating the actions with the operator;

• contacting emergency works services;

• informing the relevant authorities.

For incidents of this level, the management takes

complete control of the problem.

Level 3 – incidents (or associated incidents) that

completely stop the works, and require some co-

ordination with external organisations, e.g. industrial




pollution in a network, or a fire. Level 3 incidents

adopt the same concept as emergency level 2. As a

priority, the management will consider actions to

solve the problem and will identify as quickly as

possible the most probable delay in the restitution of

works. During this type of crises, the role of the

management is essential, in that, all resources,

personnel, emergency works services and relevant

authorities must be assigned to control the crisis in

the best possible way.

Each of these three levels is defined using three

criteria:

• zone of influence;

• seriousness;

• management of the emergency.

7.4.2 Establishment of Emergency Response Plans/Procedures

An effective Emergency Response Plan (ERP) shall

be an essential element of the Department’s

strategy for dealing with operational emergencies.

Included in this should be a system for

avoiding, or at worst, minimising pollution during

emergencies.

An ERP should enable operators to respond to

incidents in a timely and cost effective manner. In

this respect procedures should:

• Be comprehensive, yet short and easy to

read;

• Be simple, with a minimum of bureaucracy.

ERPs need to take account of the department’s

operational arrangements and will vary from one

organisation to another. However, an ERP should in

general address the following issues:

• Communication strategy that identifies, for

each level of failure, the communication that

is to occur. These could include

communication with the emergency

services, local authorities, other

organisations concerned, customers,

internal department communications, and

the media;

• Management systems, including systems

that give an early warning of problems,

pollution management, alerting staff on site

and clean-up procedures and follow-up

reviews;

• Information, including contingency plans and

access to reliable and appropriate

information/databases and resources, etc.;

• The above elements are all worthless unless

the people concerned know how to use

them. Any site ERP will depend for its

effectiveness on staff training. All staff and

contractors working on site should be made

aware of the plan and should know their role

if an incident occurs. Exercises should be

carried out periodically to familiarise staff

with the operation of the plan and to test its

effectiveness. Records of staff training

should be maintained;

• Review and follow-up systems of ERP, e.g.

to determine why a failure occurred, and

how to ensure that there is no repeat

incident. Any failure discovered through the

exercises should be managed through the

QA corrective action system. In order for the

plan to remain effective, it is vital that it is

regularly reviewed and that any significant

changes are reflected in a revised plan.

Ensure that revised copies are sent to all

plan holders and that old versions are

destroyed.

Finally, the document must be retained by all

personnel, in a simplified version that defines their

personal responsibility. All personnel must be

retained in the system, and the communication

strategy must be part of exercising the ERP.

‘Client’ Procedures: It is important in any

emergency to respond quickly to correct the

situation, learn from the experience and restore

confidence. An ERP will ensure positive action is

taken and the duration of the problem is minimised.

Important factors are co-ordination and teamwork,

and all Department staff must familiarise themselves

with the Plan so that they fully recognise their own

roles within a team when dealing with any incident.

Management of Specific Types of Incidents on

the Whole System: An incident is defined as an

unexpected, unplanned and undesired event that

results in physical harm (injury or disease): i) to

individual; ii) damage to property; iii) near miss; and




iv) any combination of these effects. The

management of the incident must follow a procedure

that is agreed between all parties, taking into

consideration the local law.

An effective incident management procedure should

be an essential element of the Department’s

strategy for dealing with operational emergencies.

Included in this should be systems for avoiding, or at

worst, minimising pollution during emergencies.

The type of emergency reported will vary from

incidents such as a blockage and flooding, to less

defined problems such as a depression in the road.

Such reports may be from customers, contractors,

from highway authorities, or others.

In case of a fatal or major accident, notification shall

be forwarded to the Department Representative.

Site/Location Specific Procedures: Irrespective of

the site and/or location of an incident, all emergency

enquiries and demands should be reacted to

promptly and appropriately. Notice of the incident

will come from one of the following sources:

• Customer/public complaint;

• Operations notification;

• Department notice (pumping station or

treatment works breakdown).

A well-prepared ERP will define the organisation,

the methods of intervention and the courses of

action in the case of incident or accident, with least

possible delay, following any unforeseen damage or

safety problem. Actions taken within the framework

of the ERP would intend to:

• Make the installations safe and limit the

consequences of an accident;

• Guarantee that the emergency services and

responsible authorities are alerted.

Interaction With Other Authorities: The ERP shall

include details of the organisations capable of

assisting in the various areas and their ability to be

brought together outside normal working hours.

Interaction and co-ordination with other authorities,

consultants and contractors is essential to effectively

manage an emergency, also with:

• Emergency Services;

• Emergency Response Teams;

• Other Service Providers;

• Armed Services, where necessary;

• The Media.

7.4.3 Emergency Plant and Equipment

Provision of specialist plant and equipment in an

emergency situation in a public utilities environment.

These shall include, but not limited to, the following:

• Lifting and salvage equipment ;

• Surface supplied air equipment;

• Rescue and diving equipment;

• Swiftwater rescue equipment;

• Flotation gear;

• Full face masks;

• Rope rescue equipment;

• Ventilation equipment;

• Sealed retracting lifeline with retrieval;

• Tripods / winches/ life-lines / gas detectors /

communications equipment / etc.

7.4.4 Public Health and Environmental Considerations

Most industrial and commercial sites have the

potential to cause significant environmental harm

and to threaten water supplies and public health.

ERP guidance notes will, if followed, reduce the risk

of an incident occurring and often minimise

expenditure. However, there will always be a

residual risk of a spillage or a fire that could cause

serious environmental problems. In addition to these

obvious threats posed by spillage of sewage,

chemicals and oils, even materials which are non-

hazardous to humans, such as foods and

beverages, can cause serious environmental harm.

The run-off generated in the event of a fire can also

be very damaging.

The health and environmental impact of such an

incident may be long term and, in the case of ground




water, may persist for decades or even longer. As a

result, the legal consequences and clean-up

operation can be costly. Sewers, culverts, drains,

water distribution systems and service ducts all

present routes for pollutants to travel off-site. As a

result, the effects of a discharge may not be evident

on site but may become apparent some distance

away.

In most cases, an incident of this kind need not

result in serious environmental damage, providing

appropriate pollution prevention measures are in

place or immediately available.

7.4.5 Safety Considerations

In order to effectively manage sites from a safety

perspective, the Department shall ensure all its

contractors shall have site specific training manuals.

Typical examples are:

• Permit to work system;

• Permit to work on HV equipment;

• Risk assessments;

• Safe confined space entry procedures;

• Sludge digestion tanks;

• Safe hand tool procedures.

Wastewater collection, treatment and disposal

systems contain numerous hazards and can be

highly dangerous environments in which to carry out

any task, from a simple inspection, to physical

maintenance works.

All personnel involved in carrying out, planning or

supervising assets/plant operations work should

receive training (general and specialised), to

increase awareness of hazards associated with their

work, so that they are able to recognise potential

dangers and their effects.

The Department will meet all its statutory safety

duties and aspire to those standards generally

recognised as being best or approved practice in

order to ensure, so far as reasonably practicable,

the health, safety and welfare of the public,

employees, contractors and others affected by its

operations.

7.4.6 Feedback and Optimising Emergency Response

It is in the interest of the Department to provide an

efficient response to problems in order to avoid

incidents that have the potential to result in pollution

and when an incident occurs, to minimise any

resulting pollution. Serious failures can cause

disruption, health risks, a loss of service, a poor

image to customers and unnecessary expenses.

7.4.7 First Aid Arrangements and Emergency Procedures

In an emergency situation, the experienced person

or team member renders First Aid, assesses the

situation, and then summons assistance. Clearly

state the position, problem, people involved and

emergency service required. As soon as practicable,

advise the appropriate safety office and local

depot/team of the occurrence.

In rendering 1st Aid the following points should be

remembered:

• In all emergency situations, the rescuer

must:

1) Assess the situation quickly;

2) Ensure the safety for the rescuer,

victim and bystanders;

3) Commence appropriate treatment

4) Where there is more than one victim,

the care of an unconscious victim

has priority.

• The rescuer should not be distracted by

victims who are calling out; their needs are

less urgent as they are able to breathe.

Note: If an emergency situation arises, the

safety of the workers, in a manhole or wet

well, is the highest priority regardless of the

task being performed or equipment being

used.

7.5 Spare Parts and Equipment

Purchasing and stock control play an important part

in effective project management and co-ordination.




All efforts are wasted if necessary supplies are

unavailable. Therefore, good logistics management

of stores spares and procurement requires a holistic

approach.

The most efficient approach requires analysis of the

supply chain to ensure ‘value added’ is maximised

at each step. It is not necessary to hold large

numbers of spares, however, it is important

to decide what spares are required. Value is through

skilled personnel applying sound maintenance

practices to ensure existing equipment function

correctly.

The following list will help to identify which spare

parts are already held and which extra items may

need to be ordered and kept available in the store:

• Routine consumables;

• Specialist items;

• Spare parts for routine equipment needing

regular and frequent maintenance.

Needs should be discussed with O&M staff

members who know exactly what is required. Clear

explanations must be given regarding what they

hope to achieve through good stock control practice.

When supply needs are decided, the information

can be collated and a stock control policy devised.

7.5.1 Targets and Objectives

Better access to communication and accurate information leads to improvements in maintenance planning, equipment scheduling and reduced inventory costs. The following objectives should be aimed for:

• Increase readiness in order that operators

may access faults more quickly;

• Improve safety and compliance; automated

forms and checklists;

• Improve asset utilisation; time, materials and

spare part usage is collected at point-of-

work and automatically updated on back-end

systems. This eliminates rework, allows for

more efficient spare parts scheduling, and

enables management to track and allocate

resources more effectively;

• Reduce inventory costs; as parts are issued

out to work sites, real-time updates to

inventory allow for accurate replenishment

and turn around, minimising costly on-hand

inventory.

7.5.2 Spare Parts Availability

The O&M teams and the related workshops and

stores will indicate the minimum stock levels

required for each item based on the quantities

required for maintaining a service. This figure is

entered on the stock card. It needs to be taken into

consideration whether an item is a local or overseas

purchase. Orders need to be placed well in advance

of the minimum stock level being reached. Forward

planning is important.

7.5.3 Storage Facilities

Storage conditions are a vitally important

consideration in hot, humid climates. As such, air-

conditioning may be necessary. Storage areas are

to be designated to prevent damage or deterioration

of spare parts and equipment, in accordance with

the manufacturers’ storage instructions.

Personnel are to make sure that spare parts and

equipment are labelled/marked in such a manner so

as to enable easy identification and location.

Frequently used parts are best kept in a central

place within the stores where staff who are familiar

with them and understand their functions can quickly

access and order them as stock levels demand.

Specialist equipment and expensive materials

should be stored in a designated area.

Displayed lists and colour-coding of shelves will

provide easier access.

Maintain the relevant documentation for

identification and location of spare parts prior to use

or delivery.

7.5.4 Inventory Control and Stock Management Procedures

A Computerised Maintenance Management

System (CMMS)




Spare parts received should be checked and

catalogued against the supplier/manufacturer part

number. If no number is apparent, a part number

shall be allocated and attached to the

component(s) packaging. Data against each

component shall then be recorded into a:

• Computer and linked to accounting and

Management Information System (MIS).

Data can be entered more accurately and in

a timely manner and is easily accessible;

• Show a running balance of the quantity of

the specific item;

• Should be checked each month by someone

in authority to ensure accuracy and also to

enable monitoring of the general usage in

each department.

Noting the monthly usage is useful when considering the annual budget and requirements for the year ahead. An end-of-year stocktaking exercise is required for correct auditing procedures.

7.6 Records

Information shall be kept in two ways:

• Real-time data and trends stored on

telemetry system, e.g. water flows in

different networks;

• Data and trends stored on CMMS or in

technical reports such as spreadsheets.

All computerised data shall be downloaded onto disk

and archived. Typical examples of information to be

recorded are as follows:

• Flows of wastewater in various networks;

• Process alarms and event;

• Personnel movement and operation times;

• Salinity measurements;

• Electricity consumption;

• Chlorine consumption;

• Digester performance.

Permanent records will be kept as part of the

operation and maintenance plan, but not limited to:

• Asset inspections;

• Asset condition;

• Test and inspection records;

• Commissioning reports;

• O&M procedures;

• Manufacturer’s manuals;

• Networks drawings and documents;

• Spares and chlorine procurement.

7.6.1 Operational Records

The following records, documents, drawings and

inventories are essential to the operation of assets:

• Equipment and maintenance inventories;

• Operation records;

• Laboratory inventory;

• Asset engineering and specifications;

• Asset documents and drawings;

• Discharge monitoring reports;

• Industrial discharge permits;

• Financial records.

At least one complete set, hard copy and/or

computerised data, of current/working records of

assets information, and ‘as-built’ drawings, shall be

kept in a safe place. Computerised information shall

be backed-up daily. Back-up copies should be

stored at separate locations.

7.6.2 Records of Scheduled Maintenance

Information relating to all scheduled (planned)

maintenance programmes shall be scheduled

through CMMS, and work orders dispatched to the

work teams together with the responsive

maintenance requests. Work orders shall give

details of all parameters to be monitored and items

to be inspected. Where a deviation from normal

operating parameters is observed, this is noted and

further maintenance investigation/action will be

taken. This information can be used for future

maintenance programmes.




7.6.3 Records of Non-Scheduled Maintenance

Provision of resources and systems to deal with

unplanned events within an agreed target time.

Priorities will be made as follows:

• Quick assessment of problem – can it be

resolved?

• Safeguard process – reduce any impact on

environment and community;

• Detailed inspection – formulate plan of

action;

• Mobilise resources – personnel, materials;

• Fix problem;

• Report on problem and ways to prevent

recurrence in future.

Information relating to all scheduled (planned)

maintenance programmes shall be scheduled

through CMMS and used for future maintenance

programmes.

7.6.4 Records of Emergencies

Reports dealing with emergencies shall be reported

within an agreed time period and shall include, as a

minimum, the following points:

• Established points of contact;

• Recorded details of the incident;

• References to previous reports;

• Determined responsibility;

• Assessed action required;

• Advice to informant of action taken;

• Update of asset records;

• Assessment and recommendations for

further work.

7.6.5 Recommendations for Reporting of Operation & Maintenance

Reports shall be produced on a daily, weekly,

monthly, quarterly and annual basis, as required:

• Daily reports shall concentrate on day to day

issues such as equipment out of service,

unusual occurrences, daily flows, chlorine

consumption, etc.;

• Weekly reports detail the planned

maintenance due in the following week;

• Monthly reports summarise the activities

during the month and provide details, such

as; quality of effluent, digester and drying

bed performance.

7.6.6 Records of Existing Assets, Including GIS and Electronic Media

This involves collection of existing records,

standardisation of formats and update of records.

Data collected from various sources will be stored in

CMMS. This has the capability of providing reports,

generating graphical trends of asset performance

and undertaking statistical analysis of data,

providing an understanding of asset behaviour.

7.6.7 Procedures for Maintenance and Updating of Asset Databases

Maintenance and updating of asset system maps,

documents and records is of utmost importance.

Many of these very important records may be on

paper and or in Geographical Information System

(GIS) format. Whatever the format, there will be

procedures in place for maintaining the system and

adding system improvements. GIS assists in

accessing the information and keeping the data

current.




7.6.8 Verification, Updating and Maintenance of ‘As-Built’ Drawings, Documents and Manuals

Updating of ‘as-built’ records will be an activity as

important as the maintenance work itself and must

be seen as an active part of the asset maintenance.

Such records shall, as a minimum, include:

• Visual inspection of manholes/chambers,

etc.;

• Cleaned pipes in km/month, assessed

according to size or profile;

• No. of blockages occurring in each network

sewer;

• No. of manholes whose structural condition

have been recorded/month;

• No. of manholes structurally repaired/month;

• No. of storm drains cleaned/month;

• No. of storm drains whose structural

condition have been recorded/month;

• No. of storm drains structurally

repaired/month;

• CCTV inspected pipes/month subdivided

according to dimension or profile in km;

• Results of salinity measurements with the

aim of localising and quantifying infiltration;

• Construction works, number of damaged

reports completed for third parties, and for

which repairs were commissioned.

7.7 Capacity Review

The O&M responsibilities will include the

measurement of asset performance parameters that

monitor the efficiency of the assets, and their spare

capacity against actual daily demand. The data will

be recorded and used to measure operational

efficiencies against maintenance requirements, and

predict the future asset upgrade requirements. This

will result from a whole of life cycle cost analysis,

being constantly studied on a rolling basis.

7.7.1 Guidelines for Monitoring and Reporting of Operational Capacity

Maintaining historical records of key operational

parameters such as:

• Pumping station flows;

• Pump running hours;

• Sewer surcharging and flooding;

• Sewage works inflows/outflows.

Such records will be compiled through either of the

following:

• Continuous flow monitoring by magnetic

flowmeters on rising mains;

• SCADA records on pump running hours and

sewage treatment work flows;

• Flumes/weirs on sewage works;

• Manual recording of flowmeter readings (if

there are no automatic readings).

Temporary flow monitoring equipment will also be

deployed and maintained at predetermined strategic

points in the sewerage system, to record flows for

hydraulic modeling purposes.

Sewage biological/chemical loading entering a

works will also be monitored periodically to

determine the spare treatment capacity at each

process stage of a sewage treatment works. Trade

effluent monitoring will also form part of this activity,

either against trade effluent discharge licenses (if

applicable), or monitoring of trends.

Reporting on the operational capacity will determine

any risk to the Levels of Service, and when

investment would be required to in extend the

system assets.

7.7.2 Measurement of Pump Performance Against Design

• Measurements to monitor the electrical

power taken from the electricity supply

against station flow for all duty pump

operating combinations;

• Monitoring of station system curves against

that measured at station commissioning, and




the operating points of all pumpsets on that

curve for all duty pump operating

combinations;

• Measurement to monitor the pumpset

characteristic curves head/flow, absorbed

power & overall efficiency for each pumpset.

Comparison of theoretical/new pump performance

against actual performance will be made using the

following criteria:

• Manufacturers flow/energy data;

• Installation/commissioning data;

• Actual flow/energy data determined by

temporary or permanent flow/energy meters

against variety of heads;

• Pump reliability;

• Maintenance costs.

7.7.3 Comparison of System/Part of Actual System Against Design Capacity

The above measurements will be reported to the

project coordinator, DA design section, who will

determine through hydraulic modeling and demand

forecasting, any risk to the Levels of Service, and

when there is a need to invest in extending the

system assets.




8 References

i British Standards Institution, 1990, BS1377: 1990 - Methods of test for soils for civil engineering purposes. London, BSI. ii The UK Water Industry Engineering and Operations Committee. 2003. Model Contract for Manhole Location Surveys and The Production of Record Maps. 2nd ed. Marlow, Buckinghamshire: Water Research Centre (WRc) Publications.

iii Water Research Centre (WRc). 1990. Model Contract for Non Man-Entry Sewer Inspection. 3rd ed. Marlow, Buckinghamshire: Water Research Centre (WRc) Publications.

iv Water Research Centre (WRc). 1993. Manual of Sewer Classification. 3rd ed. Marlow, Buckinghamshire: Water Research Centre (WRc) Publications. v Water Research Centre (WRc). 1993. Model Contract Document for Short Term Sewer Flow Surveys. 2nd ed. Marlow, Buckinghamshire: Water Research Centre (WRc) Publications.

vi Ministry of Civil Aviation and Meteorology, State of Qatar, 2002. Long Term Climate Report –2000, extracted from Long Period Means & Extremes of Climatological Elements, Doha International Airport, period (1962-2002), Qatar Ministry of Civil Aviation and Meteorology.

vii Bazaraa, A.S., Ahmed, S., 1991. Rainfall Characterization in an Arid Area, Engineering Journal of Qatar University, Vol. 4, pp35-50.

viii Water Research Centre, 1995, Pipelines Selection Manual, UK, WRC.

ix BSI. 1998. BS EN 1295-1:1998. Structural design of buried pipelines under various conditions of loading. General requirements. London. British Standards Institution. x Construction Industry Research and Information Association, 2002, CIRIA Report C577: Guide to the construction of reinforced concrete in the Arabian Peninsula : M Walker (ed), London, CIRIA. ISBN: 0 946691 93 2.

xi ACI 305R - Hot Weather Concreting.

xii British Standards Institution, 2000, BS EN 206-1:2000: Concrete. Specification, performance, production and conformity (AMD Corrigendum

13189) (AMD 14857). London, BSI. Notes: Amendment 13189 is Corrigendum No.1. Supersedes DD ENV 206:1992. In conjunction with BS 8500-1, BS 8500-2, BS 8500-3 and BS 8500-4 will supersede BS 5328-1:1997, BS 5328-2:1997, BS 5328-3:1990 and BS 5328-4:1990 (withdrawn December 2003).

xiii ASTM C 150.

xiv ASTM C 494.

xv British Standards Institution, 2001, BS EN 934-2:2001: Admixtures for concrete, mortar and grout. Concrete admixtures - Definitions, requirements, conformity, marking and labelling, London BSI.

xvi British Standards Institution, 2000, BS 8666:2000 - Scheduling, dimensioning, bending and cutting of steel reinforcement for concrete, London, Highways Agency.

xvii British Standards Institution, 1994, BS EN 124:1994 – Gully tops and manhole tops for vehicular and pedestrian areas – design requirements, type testing, marking, quality control (AMD 8587), London, BSI.

xviii British Standards Institution, 2000, ISO 9001:2000: Quality Management Systems – Requirements, London, BSI.

xix MMAA Drainage Dept Professional Service Agreement General Conditions of Engagement 1984.

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