HR for OnM

Human Resources needs for Operation
and Maintenance of Water Technologies

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INTERNATIONAL WATER ASSOCIATION 2015
The International Water Association (IWA) is an organisation that brings together people from across the water profession
to deliver equitable and sustainable water solutions for our world. As a global network, we aim to be the global source of
knowledge, experience and leadership for urban and basin-related water solutions.
Disclaimer:
The information and data in this report have been based on a long process of development, review, and iterations. All reasonable precautions have
been taken by the International Water Association to verify the information contained in this publication. However, the published material is being
distributed without warranty of any kind, either expressed or implied.
The responsibility for the interpretation and use of the material lies with the reader. This publication does not represent the views of the IWA
membership and does not constitute formal policy of IWA. IWA takes no responsibility for the result of any action taken based on the information
herein. IWA is a registered charity in England (No. 3597005).

List of Figures
Figure 1 From water and sanitation technologies
to staff requirements . . . . . . . . . . . . . . 08
Figure 2 A gravity dam . . . . . . . . . . . . . . . . . . 19
Figure 3 A cross-section of an earth-fill dam . . . . . . . 20
Figure 4 A typical cross-section of arch dams . . . . . . 20
Figure 5 Protected side intake . . . . . . . . . . . . . . 24
Figure 6 River-bottom intake . . . . . . . . . . . . . . . 24
Figure 7 A water well. . . . . . . . . . . . . . . . . . . . 26
Figure 8 Representation of transmission mains. . . . . . 29
Figure 9 A slow sand filtration process . . . . . . . . . . 32
Figure 10 Diagram of a rapid sand filtration plant . . . . . 34
Figure 11 A typical rapid sand filtration plant . . . . . . . 35
Figure 12 A service reservoir and connection to
elements downstream . . . . . . . . . . . . . . 37
Figure 13 Typical inflow and outflow flow rates
in a service reservoir . . . . . . . . . . . . . . 38
Figure 14 Operational water levels
of a service reservoir . . . . . . . . . . . . . . 38
Figure 15 A pumping system . . . . . . . . . . . . . . . . 41
Figure 16 Characteristic curves of a centrifugal pump . . 41
Figure 17 A centrifugal pump . . . . . . . . . . . . . . . 42
Figure 18 Centrifugal pumps assembled in parallel . . . . 42
Figure 19 Association of characteristic curves
of two centrifugal pumps in parallel . . . . . . . 42
Figure 20 Centrifugal pumps assembled in series . . . . 42
Figure 21 Association of characteristic curves
of two centrifugal pumps in series . . . . . . . 42
Figure 22 Inspection, condition assessment and
failure risk evaluation of pipes . . . . . . . . . . 45
Figure 23 Representation of a water supply system. . . . 49
Figure 24 Different layers in a GIS system . . . . . . . . 54
Figure 25 An orifice plate . . . . . . . . . . . . . . . . . 56
Figure 26 A ventury flow meter . . . . . . . . . . . . . . . 56
Figure 27 Pitot tube . . . . . . . . . . . . . . . . . . . . 57
Figure 28 Typical Annubar flow meter . . . . . . . . . . . 57
Figure 29 A turbine flow meter . . . . . . . . . . . . . . . 57
Figure 30 A vortex flow meter . . . . . . . . . . . . . . . 57
Figure 31 An electromagnetic flow meter . . . . . . . . . 57
Figure 32 A transit-time ultrasonic flow meter . . . . . . . 58
Figure 33 An ultrasonic Doppler flow meter . . . . . . . . 58
Figure 34 Pitot tube type Cole . . . . . . . . . . . . . . . 61
Figure 35 Insertion turbine flow meter . . . . . . . . . . . 61
Figure 36 Insertion electromagnetic flow meter . . . . . . 61
Figure 37 Profile of velocities throughout a
given diameter of a pipe . . . . . . . . . . . . . 62
Figure 38 Pressure expressed in terms of
height of liquid column (P) . . . . . . . . . . . 62
Figure 39 Determination of the head loss generated
between points 1 and 2 of a pipeline . . . . . . 63
Figure 40 Testing the accuracy of a flow meter . . . . . . 64
Figure 41 Characteristic curves of a centrifugal pump . . 64
Figure 42 Relationship between pressure reduction
and leakage reduction in a piped distribution
system for different values of n . . . . . . . . . . 66
Figure 43 Steps in implementing a pressure
management area (PMA) . . . . . . . . . . . . 67
Figure 44 Approaches for managing real losses . . . . . 72
Figure 45 Error ranges for a meter of nominal flow
(Qn) 3.5 m3
/h (classes B, C) . . . . . . . . . . 75
Figure 46 Oscillating piston flow meter . . . . . . . . . . 77
Figure 47 Side view of a nutating disk meter . . . . . . . 78
Figure 48 Plan view of a single-jet water meter . . . . . . 79
Figure 50 Woltmann meter, horizontal vane (Elster). . . . 81
Figure 51 Cross-section of a horizontal vane
Woltmann flow meter (Elster) . . . . . . . . . . 81
Figure 52 Typical composition of a combination meter . . 82
Figure 53 Main steps in developing a WSP . . . . . . . . 87

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List of Tables
Table 1 Linking the O&M staff with technologies
and processes . . . . . . . . . . . . . . . . . . 12
Table 2 Example: O&M staff for non-revenue
water management . . . . . . . . . . . . . . . . 13
Table 3 Matrix of training needs . . . . . . . . . . . . . . 15
Table 4 Selected areas of knowledge for training
of personnel involved in O&M in a typical
water utility. . . . . . . . . . . . . . . . . . . . . 16
Table 5 Selected personnel involved in O&M of dams. . 21
Table 6 Selected categories of staff involved in
O&M of intakes of raw water and respective
references to sample job description . . . . . . 25
O&M of wells and respective references
to sample job descriptions . . . . . . . . . . . . 28
Table 8 Selected categories of staff involved in O&M
of water transmission mains and respective
references to sample job descriptions . . . . . . 31
of slow sand filtration plants and respective
of rapid sand filtration and respective
of service reservoirs and respective
of pumping stations and respective
references to sample job descriptions . . . . . 44
Table 13 Condition assessment technologies . . . . . . 47
condition assessment and respective
of piped water network and respective
mapping and respective references to
sample job descriptions . . . . . . . . . . . . . 55
Table 17 Main types of flow meters with main
characteristics . . . . . . . . . . . . . . . . . . 59
of flow meters and respective references
hydraulic surveys and respective
Table 20 Selected categories of staff involved in pressure
management and respective references
V
Table 21 Elements of a water balance . . . . . . . . . . . 69
water loss control and respective
Table 23 Characteristics of class B and C water
meters according to their nominal flow
rates (ISO 4064:1993) . . . . . . . . . . . . . . 76
Table 24 Metrological characteristics of class C
oscillating piston meters . . . . . . . . . . . . . 76
Table 25 Metrological characteristics of nutating
disc meters (according to AWWA C700) . . . . 78
Table 26 Characteristics of single jet water meters . . . . 79
Table 27 Multi-jet water meters: metrological
characteristics for classes B and C (ISO 4064) . 80
Table 28 Metrological characteristics of horizontal vane
Woltmann meters for class B (ISO 4064) . . . . 81
water meters and respective references
Table 30 Example of water testing requirements in
urban systems . . . . . . . . . . . . . . . . . . 86
Table 31 Selected categories of staff involved in water
quality control and surveillance and respective

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Contents
Acknowledgements �� 03
Foreword�� 05
Introduction ��07
Objectives of the document ��07
Who should use this document?��07
Approach adopted��07
Limitations of the document �� 08
How is the document organised? �� 09
Part 1:
Linking Operation And Maintenance To Human Resources 11
Human resources for operation and maintenance
of urban water supply systems��11
Assessment of needs and planning of OM
staff and training �� 14
Links to other parts of this document�� 18
Bibliography�� 18
Part 2:
Fact Sheets On Selected Technologies 19
Fact sheet 1: Dams�� 19
Fact sheet 2: Intakes of surface water �� 23
Fact sheet 3: Wells�� 26
Fact sheet 4: Water transmission systems �� 29
Fact sheet 5: Slow sand filtration plants �� 32
Fact sheet 6: Rapid sand filtration plants �� 34
Fact sheet 7: Service reservoirs ��37
Fact sheet 8: Pumping stations ��41
Fact sheet 9: Condition assessment �� 45
Fact sheet 10: Piped-water network
Fact sheet 11: Survey, mapping and GIS�� 53
Fact sheet 12: Flow metering�� 56
Fact sheet 13: Hydraulic survey��61
Fact sheet 14: Pressure management �� 65
Fact sheet 15: Non-revenue water management�� 69
Fact sheet 16: Customer metering�� 75
Fact sheet 17: Water quality monitoring and surveillance85
Part 3:
Generic Job Description Of Selected
Operation And Maintenance Personnel 89
Senior officers�� 90
Supervising staff (technical)��91
Administrative staff�� 99
Technical staff�� 104

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Acknowledgements
The International Water Association (IWA) wishes to express its appreciation to all whose efforts made this document
possible. In particular, IWA gratefully acknowledges the contributions of the following specialists, who contributed to and
reviewed the publication: Bado Mnthali; Carla Laucevicius; Eamon Sullivan; Farooq Janjua; Janelcy Alferes Castano; João
Pedro Pitta; Pham Ngoc Bao; Ribia García Arrazola; Roland Liemberger; Rongchang Wang; Xu Wang.
Significant inputs to different draft versions were provided by Reggie Indon and Ronaldo Padua (Maynilad Services,
Philippines).
Special mention should be made of the overall management of this process by Kirsten de Vette of IWA. Without her
leadership, managerial guidance and quality assurance, preparing this document would not have been possible. Jose Hueb
was the lead author of the document.
The development of this document was generously supported by the Water Supply Division (WSD) of the Japanese
Ministry of Health, Labour and Welfare, through the Operation and Maintenance Network.

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Foreword
This document has been prepared as a response to the conclusions of assessments addressing national human resource
capacity in the water and sanitation sector conducted by IWA in 15 countries. The results highlighted enormous deficien-
cies with regard to operation and maintenance (OM) personnel. The report “Investing in water and sanitation: increasing
access, reducing inequalities” prepared by the UN-Water Global Analysis and Assessment of Sanitation and Drinking-Wa-
ter confirmed these findings by indicating that OM is among the top three issues that would benefit most from strength-
ened human resources.
Sustaining investments in infrastructure and delivering services in a safe and sustainable manner require sufficient and
well-trained personnel to operate and maintain the systems effectively and efficiently. The reality, however, is that many
water utilities count on limited financial and human resources, and thus face serious difficulties in rendering water services
according to their established objectives and mission.
A recurrent difficulty in many water utilities is to reliably assess the availability and needs of human resources, and to de-
termine the numbers and competency levels of OM personnel. This document provides guidance on how to address these
issues by examining some of the most crucial components of the water supply system as well as some of the processes in-
volved in operating and maintaining such components and the typically associated functions. Although this document offers
important guidance on OM and staff requirements for the different parts of water supply systems, it should not be used as
a blueprint for application in all utilities. The approaches proposed here should be adapted and further developed for each
specific need of different water utilities.
The Operation and Maintenance Network (OMN), which led the production of this document, has produced several
tools addressing different aspects of OM of water and sanitation systems, both in rural and in urban areas. The network
comprises water suppliers, government agencies, international organisations and other stakeholder groups, collaborating
together to raise awareness and develop capacities to effectively address OM of water supply and sanitation systems and
protect public health.
NIPH
Dr. MASAKI SAGEHASHI, Coordinator of Operation and Maintenance Network
National Institute of Public Health, Japan
IWA
Dr. GER BERGKAMP, Executive director
International Water Association (IWA is the secreteriat of the OMN)

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Introduction
In 2014, IWA published a first-of-its-kind study on human resources in the water, sanitation and hygiene (WASH) sector. It
concluded that in many developing countries there are not enough water professionals to attain universal access to water
and sanitation. Moreover, the “shortages of human resources in many countries’ Water, Sanitation and Hygiene (WASH)
sector have the potential to undermine the progress made over the last two decades in increasing access to safe drinking
water and adequate sanitation” (IWA, 2014).
The sustainability of water and sanitation infrastructure can be seriously affected by a lack of both effective and well-re-
sourced operation and maintenance (OM) facilities and an enabling institutional framework. Inadequate OM of water
supply and sanitation systems contributes to a vicious cycle where, in the absence of effective services, the OM and cap-
ital costs cannot be fully recovered, which in turn prevents new investments and leads ultimately to a poor service delivery
that compromises public health. And this is exactly the area that, according to IWA human resource assessments (IWA,
2014), is chronically neglected, with financial and human resources inadequately allocated.
To address this neglect, the assessment recommended that further in-depth research needed to be performed on the
skills and education levels required to operate and maintain water systems, to understand what efforts (i.e. planning and
training) are needed to fill the OM human resources gap in the short and long term. This document offers an initial thinking
on how to address these issues and should be followed by more specific and detailed developments addressing specific
parts of water supply systems as well as the categories of staff required to operate and maintain the system.
OBJECTIVES OF THE DOCUMENT
The objective of this work is to follow up on the IWA Human Resource Capacity Gaps study (IWA, 2014) by developing a
brief description of the main technologies involved in producing and distributing drinking water in urban areas, the functions
and skills involved in operating and maintaining such technologies, and to provide guidance to determine the staff needs to
undertake such functions and conduct the required tasks accordingly.
WHO SHOULD USE THIS DOCUMENT?
This document is aimed at a variety of stakeholders:
• Water utilities: as a guide for determining human resources required to operate and maintain the different types of
technologies;
• Policy-makers: to help understanding the human resource implications of different technology options;
• Education institutes: to help characterise the demand for skills within the sector and establish curricula and
courses to meet such demand;
• Training institutes: to contribute to a better understanding of the demand for continuous learning and education of
water professionals.
APPROACH ADOPTED
This document attempts to identify the main functions involved in operating and maintaining different “technologies” in urban
systems as well as the type of staff required to undertake such functions (Figure 1). The term “technology” in this document is
not used in the strict sense of machinery and equipment, but in a wider sense providing a broad categorisation of conjuncts of
equipment with specific functions within a water supply system. In the same way that, for instance, a water treatment plant is
considered a “technology” in this document, parts of the treatment plant can be also be considered as “technologies”.

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This document is mainly aimed at urban water supply systems in low- and middle-income countries, as similar efforts for rural
systems have already been made (WHO, 2003). The technologies, on which the document is based, deal with water supply from
source to distribution.
Urban water supply “technologies” differ from rural ones in that they are complex structures comprising myriad interlinked
technologies and processes, each of which is associated with functions that form the basis for staff profiles and needs.
The concept of “technology” in this document addresses the following main issues: the physical components of the water supply
systems and the processes involved in operating and maintaining such components (Figure 1).
The description of activities inherent to each process as well as the identification of the people needed to perform such
activities depend not only on the generic functions (ultimately, a description of activities) but also on the complexity of the
system, level of sophistication of the facilities, instrumentation, etc. The definition of the numbers and specificity of staff
needs requires a good knowledge of the system where the staff will perform their work. Thus, it needs to be done on a
case-by-case basis.
The “technologies” tackled in this work by no means reflect the whole conjunct of water supply physical units and sub-
units and the processes involved in operating and maintaining such infrastructure. The technologies addressed here should
be viewed as a sample to stimulate customised work tailored to the actual needs of existing systems.
LIMITATIONS OF THE DOCUMENT
A major limitation of this document is the fact that it is not possible to foresee all the technologies and processes, and all
the staff needed to operate and maintain them in a generic manner. Each system has its own particularities that require the
development of materials similar to those proposed in this document, taking into account the special needs and features of
such systems.
Similarly, it is not possible to foresee all the types of personnel required to operate and maintain water supply systems.
Examples are given here on possible types of staff required to operate and maintain the identified technologies, but this
should not be taken as a blueprint for application everywhere.
Main
components of
the system
(e.g. pumping station,
pressure sectors,
wells, etc)
Functions for each process
(e.g. use of leak detection equipment, maintenance of meters, etc)
Description
of the typical
activities of
each function
Identification
of the people
needed to
perform
functions and
activities
System
(e.g. distribution,
treatment, etc)
Main processes
(leakage control,
metening, etc)
Figure 1 From water and sanitation technologies to staff requirements.

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Another limitation is the impossibility of quantifying human resources for OM in a generic manner. There are many external
factors, such as size, complexity, geography, financial resources available, productivity, that influence the numbers of per-
sonnel needed. This document, however, provides elements that might facilitate the determination of the staff required to
operating and maintaining existing water supply systems.
HOW IS THE DOCUMENT ORGANISED?
This document is organised in three main parts, as follows.
Part 1 deals with the conceptual aspects of the document. It includes explanations of what actions and elements OM
personnel of water utilities should perform according to the complexities and requirements of water supply systems. It pro-
vides information on the different categories of OM staff, and establishes the links between the different staff and different
technologies.
Part 2 is a collection of fact sheets dealing with a selection of water supply technologies and processes involved in OM.
The fact sheets include a brief description of each technology, its OM functions, the potential OM problems, and sug-
gestions on some key personnel to be involved in operating and maintaining such technology. Bibliographical references
are shown at the end of each fact sheet.
The “technologies” addressed in this document are by no means exhaustive and do not represent all technologies and processes
involved in a water utility. To be meaningful, utilities should identify the different components of their water supply system (e.g.
water treatment plant), from source to points of water delivery, and successive sub-components. They should then conduct the
exercise proposed in this document according to their own needs. Rather than the few exemplary fact sheets presented in this
document, a water utility might need to develop myriad fact sheets to address their specific needs.
Part 3 provides generic job descriptions of selected OM personnel. Information is provided on the summary of functions,
example of duties, what knowledge is required by the staff, the experience required and the education more likely to be
compatible with the expected functions and duties. Different OM staff members have different degrees of involvement
with each technology. Normally, one single staff member may be involved in operating and maintaining various technologies.

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Part 1: Linking Operation And Maintenance To Human Resources
HUMAN RESOURCES FOR OPERATION AND MAINTENANCE OF URBAN WATER
SUPPLY SYSTEMS
Safe drinking water and adequate sanitation facilities are a major requirement for improvement in community health and
economic development. Maximum health benefits will be accrued when the water supply systems operate continuously and
to full capacity. Undertaking the operation and maintenance (OM) functions and actions effectively and efficiently requires
the strengthening of the technical, operational and managerial capabilities of the OM staff. The management orientation
should aim at a service-oriented approach, at the same time looking at the social aspects of the water services but also at
the sustainability of such services.
Conducting effective OM functions requires trained and motivated staff. It is essential that the organisation responsi-
ble for OM has well-qualified, experienced and efficient staff. Human resource assessment, planning, as well as human
resources (HR) management and development (training programmes, career plans, performance evaluations and adequate
salary systems) are crucial to improve staff performance (Brikké F, Bredero M 2003).
The operation of water supply systems is aimed at the use of human resources, equipment, materials and facilities to
transform raw water into treated water and to convey such water to users, complying with the current legislation, with a
maximum of efficiency and effectiveness and at a minimum cost.
Maintenance is the set of techniques and procedures that aims to foresee possible failures of the water supply system
and its components, and to act preventively to minimise the risks of disruption and to proceed, in the case of disruption, to
a swift repair. Sound maintenance services should keep the production and distribution processes to the minimum possible,
ensuring the maximum reliability of the water supply system with a minimum cost.
CATEGORIES OF OM STAFF
The OM functions are performed in general by a) senior officers; b) supervising staff; c) administrative staff; d) technical
staff; e) operators. While the first two categories provide the strategic and operational planning and supervise and monitor
the OM work, the last three categories actually run the system (CPHEEO, WHO, 2005).
The OM staff should know the procedures for routine tasks to be performed. While in most cities a large workforce is
normally assigned to OM activities, the skills and experience of the staff involved do not necessarily match the actual re-
quirements of the OM required for the water systems. This can be due to poor needs assessments or lack of job descrip-
tions, inadequate recruitment procedures, low remuneration, competition from other sectors and lack of training. The last
three factors are often causes of low morale and high staff turnover, resulting in even higher chances of having unskilled
and inadequate OM staff within the overall utility personnel.
Senior staff should be able to conduct the strategic planning, organisation and finance for OM including a continuous
effort towards improving the equipment and installations, as well as identifying best-practice approaches for operation,
maintenance and instrumentation. The senior staff are also responsible for ensuring that the vision and objectives of the
utility are met at all times (e.g. target volume and water quality standards). A crucial role of senior officers is talent manage-
ment and development, with human resource management being an inherent function. They are responsible for identifying
and analysing skills gaps and providing intervention to close them.
Supervising personnel should be able to monitor the performance of the staff and ensure that the best approaches are
adopted for OM tasks. The supervision staff should know the checks and inspections to be performed at specified inter-
vals to monitor and evaluate the status of the equipment and installations. They ensure that the operation and maintenance
staff perform their assigned duties promptly and properly. They have also the crucial function of conducting or ensuring
formal or on-the-job training.
Administrative staff should ensure the administrative backup for the overall OM work, including the administration of
human resources, transport, purchasing and stock of spare parts and materials, etc.

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Technicians are highly specialised staff responsible for specific aspects of OM, including instrumentation, laboratories,
maintenance of equipment, etc.
Operators conduct hands-on OM activities, normally under the guidance of a supervisor.
WATER UTILITIES SHOULD UNDERSTAND THEIR OM NEEDS
While the technologies and processes presented in Table 1 and Part 2 of this document are not exhaustive, and are to a
certain extent generic, a utility should understand its needs by making a profound analysis of its specific technologies and
processes and the respective requirements for OM staff.
In the fact sheets, presented in Part 2 of this document, the section on personnel requirements will send the reader to
Part 3, which provides generic job descriptions for each of the personnel categories suggested, with a more detailed sum-
mary of functions, example of duties, knowledge required by staff, the experience required and the education expected.
The staff categories in Part 2 and respective job descriptions in Part 3 of this document are only indicative and should not be
used as a blueprint by water utilities. This exercise should be conducted by each utility in a much more detailed manner, so that
all technologies, processes and their respective components are addressed according to the utility’s own requirements for an
effective assessment of staff needs. It is clear that the definition of staff levels and categories as well as the technologies in a
specific water utility depend upon the size and complexity of the water supply system and myriad other factors.
Table 1 Linking the OM staff with technologies and processes
Indicate here the
different senior officers
with OM functions
(e.g. Director OM)
Indicate the various
staffs with supervisory
OM functions (e.g.
maintenance supervisor,
laboratory supervisor,
etc.)
Indicate the administrative
staffs linked to OM func-
tions (e.g. procurement
officer, public information
officer, administrative
assistant, etc.)
Indicate the OM staff
dealing with technical
functions (e.g. labora-
tory technician, control
operator, etc.)
Indicate the different
categories of operators
(e.g. utility worker,
water treatment
operator, etc.)
STAFF
LEVELS
SUPERVISING
STAFF
(TECHNICAL)
ADMINISTRATIVE
STAFF
STAFF
CATEGORIES
Dams
Intakesof
surfacewater
Wells
Watertransmission
systems
Slowsand
filtrationplants
Rapidsand
filtrationplants
Servicereservoirs
Pumpingstations
Condition
assessment
Piped-waternetwork
Survey,
mappingandGIS
Flowmetering
Hydraulicsurvey
Pressure
management
Non-revenuewater
management
Customermetering
Waterquality
monitoringand
surveillance
CODE
(see exemplary
post descrip-
tions in Part 3)
Indicate a
reference code
for each post
under staff
categories
Indicate for each staff levels, its functions in connection with the technologies indicated here.
SELECTED
TECHNOLOGIES
TECHNICAL
STAFF
OPERATORS
SENIOR
OFFICERS

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As indicated above, utilities should formulate similar matrices for technologies and their components. As an example, Table
2 proposes a more detailed definition of staff categories and respective activities and processes involved in managing
non-revenue water. This example would be typical for a mid-sized utility of around 100,000 service connections that has a
high level of non-revenue water (NRW) management.
Table 2 Example: OM staff for non-revenue water management
Director OM
NRW manager
IMM supervisor
DMA supervisor
Leak detection supervisor
Instrumentation supervisor
(Telemetry and Pressure Management)
Construction management supervisor
Hydraulic Analyst
Design engineer
IMM technical staff
Leak detection staff
DMA field work staff
Instrumentation field
work staff
NRW data analyst
GIS staff
PM maintenance staff
Unauthorised consump-
tion investigation staff
Construction
supervision staff
NRW field worker
Leak repair staff
(if repairs are done in-house)
Customer meter-replacement
staff (if done in-house)
LEVEL
SUPERVISING
STAFF
(TECHNICAL)
CATEGORY
OverallNRW
Management
Pressure
management
(PM)
Unauthorised
consumption
control
NRWmonitoring,
dataanalysisand
reporting
IntegratedMeter
Management
(IMM)
DMAdesign,
establishmentand
management
DMAflowand
pressuredata
telemetry
NRWrelatedGIS
improvementand
utilisation
Leakdetection
Leakrepair
Pipereplacement
Indicate for each Category his/her activities with regard to each of the functions above.
FUNCTIONS/ ACTIVITIES
TECHNICAL
STAFF
OPERATORS
SENIOR
OFFICERS
ABBREVIATIONS:
NRW — Non-revenue water MM — Integrated meter management DMA — District metered area
PM — Pressure management GIS — Geographical information system

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Water utilities should have well-defined duties and responsibilities for all these categories of employees. Formulating such
a well-defined set of duties and responsibilities requires a profound knowledge of the actions required to keep each piece
of equipment or installation in good working condition as well as the competencies required to fulfil the duties.
The required competencies (i.e. skills, knowledge, abilities) to effectively perform OM should be clearly defined and up
to date. Equally important is to define the minimum qualifications and characteristics of people who will be handling the
position, and to critically assess if current and potential team members have these necessary qualifications and characteris-
tics. Hence, HR processes such as recruitment, training and development, and compensation, which all promote employee
engagement and employee development, should be aligned with what is actually needed to have an effective OM team.
In many utilities, staffing with a sufficient quantity of personnel who have adequate qualifications is a major problem. In most
instances this is due to financial constraints. It is common in many utilities to outsource OM activities to experienced con-
tractors. By adopting this practice, the utilities may keep core activities in house and outsource those that can be delegated to
private contractors. Such approach does not preclude the need for conducting the exercise proposed in this document.
The list of competencies and the level of proficiency vary according to the technology under consideration. For less com-
plex OM systems the list of competencies and level of proficiency may be simpler and less demanding. For more complex
OM systems, the list of competencies may be larger and the level or proficiency may be higher. The fact sheets in Part 2,
while considering different contexts (and procedures and working relations on-site), are the basis for formulating or revising
the description and quantification of posts. Every post in the water utility should have a well-thought-out description of func-
tions and tasks. This is especially important for recruitment, management, supervision and career development.
ASSESSMENT OF NEEDS AND PLANNING OF OM STAFF AND TRAINING
ASSESSMENT OF NEEDS
Based on the utility’s understanding of OM functions and tasks, it is possible to determine the degree to which this re-
quirement is being met through the existing personnel.
First, there is a need to determine the set of functions and tasks required to undertake properly the OM functions of the
water utility (see previous section). Such functions and tasks are grouped according to the levels of staff required. Second-
ly, an estimate should be made of the numbers of staff in the different categories required to undertake the OM functions
at the utility effectively.
Next, the current staff profile needs to be determined. The professional profile of the staff dealing with OM in the water
utility should be carefully formulated, including details of job holders with adequate knowledge and skills. Professional pro-
files should address at least the following aspects for each staff member in the water utility:
• Education, achievements, skills, training;
• Effectiveness in conducting his/her work;
• Job satisfaction;
• Information on the culture and communication process within the work place;
• Problems in learning basic skills and applying them successfully;
• Gap in knowledge, lack of skills or motivation;
• Areas where competence levels are not up to standards;
• Areas where future changes in work process or methods or job responsibilities indicate training needs.
Based on the analysis of these aspects, it is possible to determine either the training needs to make the personal profile of
the staff match the requirements of each post or the need to develop additional job descriptions and recruit new staff to
take up the required functions and undertake the identified tasks. In addition to training, there is a need to adopt staff devel-
opment approaches that lead to an improvement in staff performance at all levels.

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TRAINING
Training is a planned process to modify attitudes, knowledge or skills through learning to achieve effective performance and
to develop the abilities of the individual to satisfy the current and future needs of the water utility.
The existing or new staff chosen to perform the functions and tasks contained in the OM planning process may have to
be trained through formal classroom training courses or “on the job training”. This training is essential to prevent inade-
quate OM, poor use of equipment and poor workmanship, which could compromise the ability of the utility to deliver the
services with good regularity, continuity and quality at affordable costs. For certain categories of staff, especially those
dealing with grass-root OM, on-the-job training can be more effective than classroom training. A rule of leadership devel-
opment states that only 10% of learning occurs from structured training, 20% from coaching and mentoring and 70% from
on-the-job experience and assignments (Lombardo Eichinger, 2000).
Managers and supervisors deserve special attention in the training process. They are responsible for strategic decisions
that can either help the water utility towards effective and efficient services or can jeopardise the ability of the utility in
delivering its services properly. Managers and supervisors are also crucial in terms of motivating the staff in a process of
self-development and by helping in designing and implementing staff training.
An assessment of training needs should be conducted to match different requirements, as follows:
• The requirements of the organisation as a whole;
• The requirements of the departments/divisions/teams within the organisation;
• The requirements of individual employees through personal development plans.
• Taking the fact sheets presented in this document as an example, a matrix of areas of knowledge and categories of staff
can be prepared with the identification of the training needs for each employee (Table 3). A much wider categorisation of
staff and areas of knowledge may be needed in most water utilities. Such categorisation should be formulated on a case-
by-case basis according to the actual requirements of each water utility.
Several knowledge areas for training, intrinsic to the technologies addressed in this document as well as to the category of
staff involved, are shown in Table 4. These areas and the respective training should cover most of the needs linked to effec-
tive and efficient OM and the associated technologies considered in this document.
TECHNOLOGIES
Table 3 Matrix of training needs
AREA OF
TRAINING
MANAGEMENT General management
Supervision skills
Dams
Intakes of surface water
Pumping stations
Wells
Water transmission systems
Slow sand filtration
Rapid sand filtration
Service reservoirs
Condition assessment
Piped-water network
Mapping
Flow metering
Hydraulic survey
Pressure management
Leakage control
Water meters
Water quality monitoring and surveillance
SENIOR
OFFICERS
SUPERVISING
STAFF
ADMINISTRATIVE
STAFF
TECHNICAL
STAFF
OPERATORS
Management staff requiring training
Technical staff requiring training

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Table 4 Selected areas of knowledge for training of personnel involved in OM in a typical water utility. Source: based on CPHEEO WHO (2005).
Corporate policy
Corporate planning
Supervision techniques
Overall management
Management information system
Organisational development
Government, bilateral and multilateral funding
Financial management
Project management
Contracts, specifications
Quality of services
Material planning and control
Import procedures
Personnel management
Human resource development
Office management and automation
Material (stock accounting)
Computer applications in office management (e.g. Microsoft Office, project management, etc.)
Organisation and methods
Programme planning and budgeting
Hydrology
Dam safety: monitoring and evaluation
Capacity estimation of impounding reservoirs
Models for management of reservoirs
Systems design
Material planning and control techniques
Water audit
GIS methods, preparation and updating of maps
Operation of wells
Operation of water transmission systems
Training of water treatment plant managers
Training of water treatment plant operators
Training in condition assessment
Operation of pump stations
Engineering drawing
Training in hydraulic survey
Electrical and mechanical maintenance
Water losses
Leak detection and location
Repairing mains, valves and other appurtenances
Swabbing, cleaning and coating pipelines
Rehabilitation and replacement of pipelines
Pipe network analysis
Pollution detection, prevention and control
Maintenance management
Energy audit
Instrumentation
Water supply systems modelling and simulation
Material testing and certification
Operation control centre
Hydraulic modelling of the water supply system
Rehabilitation of structures
Metering
Training in water quality control and surveillance
EXAMPLE OF
KNOWLEDGE
AREAS
SENIOR
OFFICERS
SUPERVISING
STAFF
ADMINISTRA-
TIVE
STAFF
TECHNICAL
STAFF
OPERATORS

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DEVELOPING A TRAINING PROGRAMME
A training programme can then be designed to address the gaps. For this to be successful, the utility needs to allocate a
sufficient proportion of its annual budgets towards staff development and training.
The HR department should prepare policies and procedures that will support the development of their staff. Such poli-
cies and procedures should take the following into account:
All staff needs to have in place a career development plan, indicating the staff member’s development goals for the year,
the means to achieve those development goals, and indicators to measure progress. In certain situations, these achieve-
ments can be linked to performance agreements and hence staff members are encouraged to progress their professional
development as well.
Secondly, the HR department needs to coordinate with all departments to assess training needs, which in turn will allow
the formulation and implementation of a training programme under good conditions of cost-effectiveness.
Thirdly, the HR department needs to evaluate whether it has the desired systems and procedures in place to make the
training programme successful. Achieving this requires the following:
• Set clear objectives and outcomes of training;
• Plan the training activities well in advance to allow proper preparation;
• Evaluate the training;
• Organise the training events properly, to reach a wider group of staff members;
• Keep a record of training events attended by staff members and respective results to help plan further training;
• Establish a knowledge management system to allow learning from professional development to be shared between staff.
Fourthly, following classroom or field training, the utility and its staff would greatly benefit from examinations to ensure that
the training was effective and reached its objectives. Certification should be issued according to a certification programme.
It is unfortunate to note that many utilities in developing countries do not count on an effective HR department focused
on staff selection, recruitment, training and development in general. This is a major drawback, which should be addressed
as a condition to improve the overall performance of staff and that of the utility itself.
Another common problem in many utilities is that it is difficult to reward staff members who, by training, become excellent
at their job. Since it is difficult to reward them with an increased salary on their present position they are often promoted to
some managerial job where their previous skills are not needed and are thus forgotten. A career development plan would
avoid this practice by devising horizontal development opportunities (increase in salary and level while at the same position)
and vertical promotions that would allow the staff to make use of their skills either to manage activities within their knowl-
edge area or to train others to perform that type of work. It is also helpful to link positive training results with promotions as
an incentive to keep staff interest in training.
Types of training
A training programme should aim at complementing the professional profile of the employees to make them match the
requirements of their respective job descriptions. In formulating the training programme, it should be determined whether
training can bridge the gap between the job description and the staff profile.
Several training modalities exist:
• Refreshing courses: to update knowledge, and enhance skills that will help motivate the staff, improve production and
efficiency and achieve corporate goals;
• Training of trainers: enables new trainers to learn the basic techniques and approaches of training or to enable
existing trainers to improve the training skills they already possess;
• Off-the-job training: training can take place in institutions outside the organisation, which are specially equipped and
staffed for training;
• Long-term training: formal educational programmes at universities, technical teaching institutions, etc., leading to a
formal diploma in the working domain of the staff member.
• On-the-job training: the trainee gets training while working on the tasks assigned to him/her.

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LINKS TO OTHER PARTS OF THIS DOCUMENT
The fact sheets presented in Part 2 of this document propose the categories of staff to undertake the functions and tasks
related to each technology under consideration. By no means are such categories exhaustive, and they should not be used
as a blueprint for application everywhere. Each utility has its own needs and each category can vary enormously in terms of
the sophistication of instrumentation and automation. The same applies to the level of training expected for each category of
employee. While highly automated systems require fewer personnel, the level of training to operate and maintain this type of
setup may require highly skilled personnel. Less automated systems may require more staff with a lower level of training. Part
3 of this document presents typical job descriptions for selected personnel in a water utility. Again, such descriptions are by
no means exhaustive and need to be adjusted according to the actual requirements of each institution.
BIBLIOGRAPHY
Brikké F, Bredero M (2003). Linking technology choice with operation and maintenance in the context of community water supply and sanita-
tion – A reference document for planners and project staff. Geneva, World Health Organization (WHO).
CPHEEO, WHO (2005). Manual on operation and maintenance of water supply systems. New Delhi, Central Public Health and Environmental
Engineering Organisation - Ministry of Urban Development, India Ministry of Urban Development (http://cpheeo.nic.in/, accessed 9 September
2013).
IWA (2014). An avoidable crisis - WASH Human Resource Capacity Gaps in 15 Developing Countries.

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Part 2: Fact Sheets On Selected Technologies
Several water technologies and processes have been selected for this document to illustrate OM functions and tasks and
to link them to the required human resources. The fact sheets presented in this section provide an overview of selected
technologies in a water supply system. By no means are they intended to exhaust the issues addressed here. The authors
have selected a bibliography for each fact sheet that provides further details on the different subject areas addressed in
this document.
Each fact sheet addresses a technology or process and contains the following elements:
• Description: brief section explaining the objectives and working principles of the technology;
• Main operation functions: this section summarises the main functions involved in making the facility work according to
expected standards;
• Main maintenance functions: describes the main maintenance activities required to make the facilities work
continuously, effectively and efficiently;
• Potential OM problems: the main problems that might occur over the lifetime of a facility;
• Staff requirements: sends the reader to generic job descriptions linked to the technology or process under
consideration;
• Bibliography: publications utilised as sources in preparing the fact sheets.
FACT SHEET 1: DAMS
DESCRIPTION
A dam is a barrier that allows the storing of water for different purposes such as the management of water flow down-
stream and the use of water for hydropower generation, agriculture, industry, municipal water supply systems, etc.
There are several types of dWam, including the following:
Gravity dams
A gravity dam is a massive structure made up of concrete or stone masonry (Figure 2). The weight of the concrete holds it
down to the ground, providing sufficient resistance against the horizontal forces impacting on the upstream surface of the
dam. This type of dam is especially indicated in the case of rivers in wide valleys or narrow gorges.
Figure 2 A gravity dam Coulee Dam, Grand Coulee, Washington. Photo: Bureau of Reclamation, USA.

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Embankment dams
Embankment dams are made up of compacted earth (earth-fill dams) or compacted free-draining granular earth containing
an important proportion of large particles (rock-fill dams). The latter dams can be further classified by types of dam section,
types of core, etc. They use their own weight to contain the forces against their surfaces. Earth-fill dams are the most com-
mon type of dam (Figure 3). This is because their construction makes use of materials from excavations and locally available
natural materials almost without any processing.
While earth-fill dams with drainage should have structural and seepage resistance, rock-fill dams have a waterproof core
that prevents water from seeping through the structure. The core is separated through a filter to prevent internal erosion of
clay into the rock fill. The impervious zone may also be on the upstream face through the use of masonry, concrete, etc.
Arch-gravity dams
Arch-gravity dams are curved in the horizontal plane and usually built of concrete (Figure 4). The horizontal thrust is taken by abut-
ments in the sides of a valley. Arch dams must be built on solid rock, as yielding material would cause a failure. The arch-gravity
dam’s structural design takes into account the gravity action and arch properties. In the case of a vertical upstream face, the
weight of the dam is discharged to the foundation. If the upstream face is sloped, the normal component of the arch ring’s weight
will be borne by the arch’s action, whereas the normal hydrostatic pressure will be discharged to the foundation, as in the case of
a vertical upstream face. This type of dam is especially indicated in narrow canyons with steep walls made up of firm rocks.
MAIN OPERATION FUNCTIONS
Normal operation
• Flows and discharges should be defined under guidelines and models, taking into account the availability of water
resources and the demand for different uses;
• The water in the reservoir should not be stored beyond a maximum level. Excess water should be discharged taking into
Atazar Dam, Madrid, Spain. Canal de Isabel II, Gabinete de Prensa e Imagen
Figure 4 A
typical cross-
section of arch
dams
Figure 3 A cross-section of an earth-fill dam

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account the capacity of both the spillway and the receiving water body downstream;
• Discharges should be made taking into account the water resources minimum needs and maximum capacity of the
receiving body downstream;
• Water flows and pressures should be monitored regularly and should be an integral part of the operational
decision-making;
• The initial filling of the reservoir should be done carefully, in a phased way, and should be well monitored to avoid a
possible accident due to leakage or any other problem;
• The water level should be recorded regularly, typically once a day. The frequency might be higher during special situations
(e.g. rainy season);
• The capacity of the reservoir should be measured regularly through bathymetry or other method to monitor its reduction by
silting;
• A record of operations should be kept to provide relevant data and help ensure the optimum management of the system.
Emergency operation
An emergency action plan should be prepared and tested dealing with emergency operations including the following: flood
warning systems; flood control through monitoring of inflow and controlled discharges; emergency emptying of the reser-
voir; evacuation of high-risk areas; rescue operations; information system involving public utilities potentially affected by the
emergency; warning, communication and transport.
MAIN MAINTENANCE FUNCTIONS
• A sound programme for preventive maintenance should be formulated and implemented accordingly;
• A programme should be established dealing with systematic inspection of the dam including its various components as
well as the reservoir and downstream installations;
• A maintenance manual (preventive and corrective) should be prepared and implemented accordingly;
• The embankment structures should be examined to look for any evidence of settlement, slope stability and protection,
seepage and drainage;
• The spillway structures should be examined in terms of control gates, operating equipment, inlet and outlet channels and
energy dissipaters;
• In the case of gravity concrete dams, systematic inspections should be conducted to look for structural cracking, stability,
hill slides, possible movements, junctions, drains, seepage, and foundations;
• In the case of embankment dams, the inspections should focus on evidence of problems such as stability, settlement,
cracks, seepage, erosion, permeability and piping;
• Keep a record of maintenance activities organised according to installations and equipment for future reference and
guidance.
POTENTIAL OM PROBLEMS
PERSONNEL REQUIREMENTS
Table 5 Selected personnel involved in OM of dams
SO01, ST03, ST04, ST05, AS01, AS02, AS04, AS05, TS01, TS02, TS12, TS14, OP01, OP02Main categories of staff involved in OM of dams
(see generic job descriptions in Part 3)
GRAVITY DAMS
Sliding of the structure
Overturning of the structure
Crushing of the structure
Seepage
EMBANKMENT DAMS
Overtopping
Erosion of upstream and downstream faces
Inadequate drainage
Inadequate foundation
Slide of slopes
Seepage
ARCH-GRAVITY DAMS
Cracks
Differential displacements of supported arch barrels
Movement along construction joints
Seepage

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BIBLIOGRAPHY
Brikké F, Bredero M (2003). Linking technology choice with operation and maintenance in the context of community water supply and sanita-
tion – A reference document for planners and project staff. Geneva, World Health Organization (WHO).
CPHEEO, WHO (2005). Manual on operation and maintenance of water supply systems. New Delhi, Central Public Health and Environ-
mental Engineering Organisation - Ministry of Urban Development, India Ministry of Urban Development (http://cpheeo.nic.in/, accessed 9
September 2013).
Food and Agriculture Organization (2001). Small dams and weirs in earth and gabion materials. Rome, Italy, FAO
(ftp://ftp.fao.org/agl/aglw/docs/misc32.pdf, accessed 18 September 2013).
Narita K (2000). Design and construction of embankment dams. (http://aitech.ac.jp/~narita/tembankmentdam1.pdf, accessed 20 September 2013).
Ragsdale and Associates. New Mexico Water Systems Operator Certification Study Guide. United States of America, Utility Operators Certifi-
cation Program NMED Surface Water Quality Bureau (http://www.nmenv.state.nm.us/swqb/UOCP/index.html, accessed 18 September 2013).
Salvato Jr J (1972). Environmental engineering and sanitation, Second edition. United States of America, John Wiley Sons.
Texas Commission on Environmental Quality (2006). Guidelines for operation and maintenance of dams in Texas. Austin, United States of Ameri-
ca, TCEQ (http://www.tceq.texas.gov/publications/gi/gi_357/gi-357.html, accessed 19 September 2013).
The British Dam Society. About dams. (http://www.britishdams.org/, accessed 9 September 2013).
U.S. Army Corps of Engineers (1994). Earth and Rock-Fill Dams - General Design and Construction Considerations. Washington, DC (http://
www.polytechnic.edu.na/academics/schools/engine_infotech/civil/libraries/hydraulics/docus/EarthRockFillDams.pdf).
United States Department of Interior - Bureau of Reclamation (1987). Design of small dams, 3rd ed. Washington, DC (http://www.usbr.gov/
pmts/hydraulics_lab/pubs/manuals/SmallDams.pdf, accessed 18 September 2013).

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FACT SHEET 2: INTAKES OF SURFACE WATER
DESCRIPTION
The purpose of the intake of raw water is to withdraw suffi-
cient quantities of raw water continuously. Intakes in large
rivers should be located so that the ports are submerged,
even under the lowest level of the surface water, and are
free from potential sources of pollution. The ports should be
sufficiently above the bottom of the stream to avoid with-
drawing sand and other materials.
A conventional solution to raise the water level of a river
is to build a weir across such a river and place the intake
immediately upstream. This solution is only feasible for rivers
of moderate size, which do not carry coarse materials such
as cobbles, boulders or debris. In the case of wider rivers,
or where there are risks of high flood flows, other solutions,
which take into account the need for building costly infra-
structure, are more appropriate.
The main conditions to be considered in designing water
intakes include the following:
• Type of surface water (e.g. rivers, lakes, canals);
• High and low water levels;
• Navigation;
• Floods and storms;
• Floating debris;
• Ice formation;
• Water velocities, surface and subsurface currents,
channel flows, and stratification;
• Location of sanitary, industrial and storm sewer outlets.
Bar racks are normally used on the openings into the intake structure to protect the intake from large floating objects.
Screens have the function of protecting the intake against floating materials, such as leaves. Screens should be made up of
corrosion-resistant materials and should be easily removable for cleaning and repairing. Intakes in large rivers and reser-
voirs should be as deep as possible.
Several types of water intake can be devised according to the conditions above. They include the following:
Protected side intake
A protected side intake provides a stable place in the bank of a river or lake, from where water can flow into a channel or
enter the suction pipe of a pump. It is built to withstand damage by floods and to minimise problems caused by sediment.
Side intakes are sturdy structures, usually made of reinforced concrete, and may have valves or sluices to flush any sedi-
ment that might settle.
Often, a protected side intake is combined with a weir in the river to keep the water at the required level. It also includes
a sand trap to let the sand settle and a spillway to release excess water. The river water may enter the side intake through a
screen, and a spillway overflow may be required. Sometimes, protected side intakes are combined with a dam and a flush-
ing sluice, which allows the upstream part of the river to be flushed.
The side intake shown in Figure 5 is used to abstract water up to 0.5 m3
/s. For larger rates of flow, the settlement bays
should be constructed with hopper bottoms to collect silt. The silt is removed recurrently by suction pipes after agitation
with air delivered through pipes to the hoppers.
There are several variations of this design to take into account issues such as bottom sediments, ice, debris in the water, etc.
Intake on Rio Blanco, Costa Rica. Source: Morris (s.d)
Floating intake structure, Brushy Creek Regional Utility Authority, USA.
Source: ASCE (2013)

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River-bottom intake
Where there is little variation between high and
low water levels, and where the rivers have a sta-
ble bed, it is possible to install a pump station on
the bank (Figure 6). This type of intake is possible
in small rivers and streams and in cases where
there is little bed-load transport. The suction pipe
should be down the bank. The water is abstracted
through a screen to protect the system against
coarse material. For this, the bars of the screen
should be laid in the direction of the current and
sloping downwards. Intake designs should ensure
the stability of the structure even under flood
conditions. Where the river does not transport
boulders or rolling stones, an unprotected intake
may be acceptable.
Floating intakes
Floating intakes for drinking water systems allow
water to be abstracted from a constant depth below the surface of a river or lake, thus at the same time ensuring the appro-
priate height for good functioning of the pumps and avoiding the heavier silt loads that are transported closer to the bottom
during floods.
The pump can be located either on the bank or on the pontoon. The advantages of placing the pump on the pontoon are
that the suction pipe can be quite short and the suction head will be constant (less risk of cavitation). If the river currents
frequently carry logs or large debris, a floating inlet needs extra protection or it will be damaged. The design of the floating
intake has to take into account the different characteristics of the site as indicated above.
Figure 6 River-bottom intake
Figure 5 Protected side intake.
Source: Twort et al. (2000).

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• Ensure that the intake system provides the adequate quantities of water to the subsequent phases of the system
(treatment, pumping, etc.);
• Operate gates and valves to ensure the adequacy of the water flow taking into account issues such as the variation of the
water level, required flow rate and maintenance;
• Where there is this possibility, operate the system so the water is abstracted at the depth that ensures the best raw
water quality.
• Inspect the bar racks regularly to ensure that they are free of large floating objects;
• Inspect the screens to make sure that it does not have excessive leaves and other floating objects obstructing the water
flow;
• Screens should be regularly cleaned through mechanical or hydraulic jet cleaning devices;
• Test and operate the intake valves, gates, and any other mechanical or electrical equipment regularly;
• Keep all the equipment well serviced and lubricated where needed.
The following factors may exacerbate the OM problems in a water intake:
• Fluctuations of water level beyond design expectations;
• Varying water quality with depth without the possibility of varying the depth of water withdrawals accordingly;
• Ice, floods, floating debris, boats and barges;
• Clogging by silt or debris;
• Water pollution;
• Erosion caused by the river current may undermine the intake structure and the bank;
• Lack of effective racks and screens to prevent entry of objects;
• Lack of space for equipment cleaning, removal and repair of machinery;
• Water source insufficient to ensure the flow rate required;
• Settlement or shifting of supporting structures which could cause binding of gates and valves;
• Worn, corroded, loose or broken parts;
• Vandalism.
STAFF REQUIREMENTS
BIBLIOGRAPHY
Brikké F, Bredero M (2003). Linking technology choice with operation and maintenance in the context of community water supply and sani-
tation – A reference document for planners and project staff. Geneva, World Health Organization (WHO).
Landers J (2013). Texas Cities Join Forces to Create Water Supply System. Civil Engineering - The magazine of the American Society of Civil
Engineering (ASCE). (http://www.asce.org/CEMagazine/Article.aspx?id=25769810817#.UmTJPfmnp48, accessed 21 September 2013).
SO01, ST03, ST04, ST05, AS01, AS02, AS04, AS05, TS01, TS02, TS12, TS14, OP01, OP02Main categories of staff involved in OM of intakes of raw water
Table 6 Selected categories of staff involved in OM of intakes of raw
water and respective references to sample job descriptions

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Morris GL. Water supply intake structures. (http://www.drna.gobierno.pr/oficinas/saux/secretaria-auxiliar-de-planificacion-integral/planagua/proyec-
to-de-caudales-ecologicos/1ra-conferencia-de-flujos-ambientales-en-rios-de-puerto-rico/Land%20Figs%20River%20Structures.pdf, accessed 21
September 2013).
Salvato Jr J (1972). Environmental engineering and sanitation, Second edition. United States of America, John Wiley Sons.
Twort A, Ratnayaka D, Brandt M (2000). Water supply, 5th ed. London, Hodder Headline Group and IWA Publishing.
Williams R, Culp G (1986). Handbook of public water systems. New York, Van Nostrand Reinhold Company.

FACT SHEET 3: WELLS
DESCRIPTION
A water well is a structure established in the ground by digging, driving, boring, or drilling to access groundwater. In urban
areas, the water is normally withdrawn from wells through electro-mechanical pumps. For peri-urban areas, other mecha-
nisms are also used such as hand-pumps, buckets, etc.
The level of the water in a well when no pumping is performed is called the static water level (Figure 7). By withdrawing wa-
ter from the well, the water level drops below the static level to a vertical distance from the static level, called the drawdown.
When the water is pumped from the well, an un-watered zone (cone of depression) is formed below the static water level. The
radius of the cone at the static water level is called the radius of influence. When two or more wells are located excessively
close together, their cones may overlap which may decrease the capacity of each well when operating simultaneously.
Figure 7 A water well

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The main types of well are the following:
• Dug wells: normally excavated by hand, they are shallow and consist of the following main components: a stone, brick or
concrete apron; a headwall (the part of the well lining above ground) at a convenient height for collecting water; a lining
that prevents the well from collapsing.
• Driven wells: made by driving a metal pipe into the water-bearing stratum. The pipe acts as the permanent casing Well-
points are normally driven by hand when depths are less than 9 m. In the case of greater depths driving tools are often
suspended from a tripod or derricks. To avoid contamination, the well should be protected from surface waters by use of a
concrete top with an apron. The well pump should be sealed and the well surroundings should be banked and tamped to
divert surface waters. The casing should be extended to at least 30 cm above the ground surface and at least 3 m below
the groundwater surface.
• Drilled wells: although there are several methods for drilling wells, the main methods are through percussion, rotary or
reverse-circulation drilling.
The percussion method consists of lifting and dropping a heavy string of tools in the borehole. The drill bit breaks or crushes
hard rock into small fragments. The size of the drill bit allows the casing to be introduced into the well after drilling is complete.
Rotary drilling is made through a cutting bit which is attached to a hollow drill rod rotated rapidly by an engine-driven rotary
table. Either water or a suspension of colloidal clay is pumped down the drill pipe, flows through openings in the bit and trans-
ports the loosened material to the surface. The clay suspensions are designed to reduce loss of drilling fluid into permeable
formations, lubricate the rotating drill pipe, bind the wall against caving and suspend the cuttings. In drilling for water, the thick
drilling clay may be forced into the aquifer and reduce the flow into the well; but new methods of reaming and flushing have
largely overcome such difficulties.
Reverse-circulation, rotary drilling is done with the flow of drilling fluid reversed with respect to the system used in the
conventional rotary method. The drilling fluid and its load of cuttings move upwards inside the drill pipe and are discharged
by the pump into a settling pit. The fluid returns to the pipe to the bottom of the hole, picks up the cuttings and re-enters
the drill pipe through ports in the drill bit.
Because of the importance of drilled wells in urban water supply systems, this is the technology that is considered in the
subsequent sections of this fact sheet.
Centrifugal pumps are normally used to pump water from a well. The most common pumps used for this purpose are ver-
tical spindle pumps. The driving motor is at the surface whereas the pump is immersed in the water.
• An operation manual should be prepared for reference by operators, which should include operating criteria, the equipment
manufacturer’s operating instructions and standard operating procedures;
• Pumping rates should be monitored carefully so the pumps function within their adequate design range;
• Excessive starting and stopping of well pumps should be avoided as this practice not only shortens equipment life, but also
consumes more energy;
• Over-pumping should be avoided as it may affect the efficiency of the system and, in the case of coastal areas, cause
saltwater intrusion;
• Prime the pump with potable water to avoid contamination;
• Keep the drain from the pump base open and free so that any leakage will be carried away from the source;
• Conduct well tests to evaluate the performance of the well;
• Make sure that the well pumping rate does not reach more than 50% of the maximum drawdown;
• Disinfect wells after original development in the following circumstances: each time the pump is removed; each time the
screen is cleaned; and, where microbial analyses indicate contamination.
• Clean well screens regularly;
• Repair or replace well screens when they are corroded or damaged;
• Inspect, operate and test regularly intake structures and related facilities;

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• Carry out regularly service and lubrication of intake facilities;
• Inspect, test and maintain regularly gates and valves.
• Incrustation, restricting the water passages from the aquifer into the well and increasing surface roughness, reducing the
capacity of the system;
• Chemical, physical and galvanic corrosion, reducing the life span of the system;
• Incorrect design and poor construction;
• Lowering of water table;
• Poor-quality water;
• Inadequate pumping design;
• Defective installation of the pumping system;
• Settlement and shifting of supporting structures;
• Excessive vibration of the pumps, motors and overall structure.
BIBLIOGRAPHY
CPHEEO, WHO (2005). Manual on operation and maintenance of water supply systems. New Delhi, Central Public Health and Environ-
mental Engineering Organisation - Ministry of Urban Development, India Ministry of Urban Development (http://cpheeo.nic.in/, accessed 9
September 2013).
Lehr J et al. (1988). Design and construction of water wells. New York, Van Nostrand Reinhold Company.
Ratnayaka D, Brandt M, Johnson KM (2009). Twort’s water supply, 6th Edition. Great Britain, Elsevier Ltd.
U.S. Army Corps of Engineers, Naval Facilities Engineering Command, Air Force Civil Engineer Support Agency (2001). Operation and mainte-
nance: water supply systems. United States of America (UFC 3-230-02; http://www.wbdg.org/ccb/DOD/UFC/ufc_3_230_02.pdf, accessed 13
October 2013).
Williams R, Culp G (1986). Handbook of public water systems. New York, Van Nostrand Reinhold Company.
Table 7 Selected categories of staff involved in OM of wells and
respective references to sample job descriptions
SO01, ST03, ST04, ST05, AS01, AS02, AS04, AS05, TS04, TS05, TS06, OP02, TS07, TS09, TS11,
TS12, TS14
Main categories of staff involved in OM of wells

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FACT SHEET 4: WATER TRANSMISSION SYSTEMS
DESCRIPTION
Water transmission mains convey raw water from the water
source to the treatment plant or directly to the consumption
area where treatment plants are not required (Figure 8).
Water transmission may occur through free-flow channels
or conduits or pressure mains. The sources of water may
be rivers, lakes, surface reservoirs and groundwater aqui-
fers. Water transmission mains also carry water from the
treatment plant to storage reservoirs or to pumping stations.
This fact sheet deals primarily with pressure mains.
Common pipes used in transmission mains are made up of ductile iron, cast iron, steel, pre-stressed concrete, high density
polyethylene, asbestos cement, etc., under myriad variants and trademarks.
Transmission systems should be designed, operated and maintained to ensure that they function under the minimum pos-
sible costs, taking into account the variables involved in such costs including flow rate, diameter, length of pipeline, head
loss, pumping capacity and OM costs.
A major tool for the effective management of transmission mains is the so-called condition assessment. It includes the
collection of information about the condition of the mains, the analysis of the data collected and the use of this information
for decision-making with regard to maintenance, rehabilitation or replacement of the pipelines (see fact sheet 9).
• All the information concerning the valve operations, water levels, pressures, flow rates and the status of pumps are
transmitted manually (by radio, telephone, etc.) or by telemetry to a control centre and to the transmitting and receiving
reservoirs. This is done hourly or in real time, depending on the operation requirements;
• The number of pumps in operation, and the status of control valves are decided according to flow rates, pressures and
water levels in reservoirs required to ensure the continuity of supply;
• The analysis of pressures and flows either at the pumping station (if there is one) or at the transmission mains, is
fundamental to identify any possible breakdowns or any other change in the regime of operation of the system;
• Operate valves and pumps according to a schedule aimed at ensuring that the hydraulic status of the system is according
to the needs in terms of water transmission;
• Keep reliable records of the transmission system’s operation indicators including pressures, flows, pumping status,
valves, etc.;
• Pressure transients are critical aspects linked to a collapse or rupture of pipelines and need to be assessed recurrently;
Figure 8 Representation of transmission mains
Water transmission main, City of Moorhead.
Source: http://www.ulteig.com/water-transmission-line

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• Hydraulic models can be useful in simulating the best possible operating options in cases of abnormal situations such
as power failure, non-functioning pumps, pipe bursts, pressure transients, etc. Such models are particularly useful for the
hydraulic analysis of complex transmission systems;
• In large and complex systems, it might be feasible to use telemetry and supervisory control and data acquisition
(SCADA) systems to capture indicators such as flows, pressures, water levels, etc., to analyse the performance
of the water supply system and take decisions to ensure that the system is operating with required efficiency. For
such large and complex systems, this is preferable to manual approaches such as the use of telephone line or radio
communication to gather the data and decide on actions;
• Keep the GIS and mapping systems of the transmission mains reliably and permanently updated. The system should
include the precise location of pipes, valves, pressure meters, flow meters and fittings. Regardless of the degree of
sophistication of such a system, entering unreliable information will obviously generate inaccurate outputs.
MAINTENANCE FUNCTIONS
• Implement a condition assessment process taking into account the priorities imposed by the importance and
vulnerability of the different transmission mains (see fact sheet 9);
• Prepare a maintenance schedule taking into account the tasks required to improve the efficiency and effectiveness of
the transmission system. The maintenance schedule is fundamental to make the most of the existing human resources
and equipment utilised for both preventive and corrective maintenance;
• Perform systematic inspection covering the whole transmission system to detect, locate and repair leaks;
• Establish standard procedures for each type of maintenance intervention, including procedures for cleaning and
disinfecting the pipelines when they need to be emptied to be serviced;
• A complete list of spare parts for the transmission system should be prepared, purchased and kept in stock to ensure
the prompt action in case of emergency or normal maintenance actions;
• Define criteria for cleaning and lining the transmission mains where the friction coefficients (e.g. coefficient C in the
Hazen–Williams equation) and inspections indicate a serious reduction in the carrying capacity of the pipelines. This
is particularly important for unlined metal pipes such as old cast iron pipes and mild steel with bare metal surfaces;
• In the case of metallic pipelines, where the electrolyte resistivity of the soil is high, it might be necessary to implement
impressed current cathodic protection (ICCP) systems to protect the mains. Such systems use anodes fed by direct
current power source, often a transformer-rectifier connected to AC power;
• Establish an effective communication strategy to inform the media and the public about interruptions in supply due to
maintenance activities.
• The carrying capacity of the pipelines may be reduced over time owing to tuberculation and corrosion. This is
especially true for unlined steel, cast iron and galvanised iron. Controlling the carrying capacity of the transmission
mains over time is fundamental to provide the decision-making elements for rehabilitation or replacement (see fact
sheet 13). Ageing may be aggravated by poor quality materials and poor workmanship;
• Leaks may occur through the glands of gate valves, expansion joints, air valves and the pipes themselves due to
failing joints or pipe failures;
• Poor functioning of gate valves or control valves: valves may be partly closed owing to different factors such as
corrosion, defective stem, gate being stuck after a long period of non-use, etc.;
• Poor functioning of air valves, pressure reducing valves and relief valves, causing reduction of flow rates or excessive
pressures;
• Old steel pipelines, especially those unlined may be subject to severe corrosion or tuberculation over time.
Pre-stressed concrete pipes may present corrosion of the pre-stressed wire or the reinforcement cage where the
concrete is not properly manufactured;
• Lack of readily available spare parts of components of the transmission system (valves, pumps, etc.);
• Meters (flow meters, level meters and pressure meters) not providing accurate measurement, which may, in turn, lead
to inadequate operation interventions.

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BIBLIOGRAPHY
Ainsworth R (2004). Safe piped water. London, International Water Association (IWA) on behalf of the World Health Organization
(http://www.who.int/water_sanitation_health/dwq/924156251X/en/, accessed 9 November 2013).
Brikké F, Bredero M (2003). Linking technology choice with operation and maintenance in the context of community water supply and sani-
tation – A reference document for planners and project staff. Geneva, World Health Organization (WHO).
CPHEEO, WHO (2005). Manual on operation and maintenance of water supply systems. New Delhi, Central Public Health and Environmental
Engineering Organisation - Ministry of Urban Development, India Ministry of Urban Development (http://cpheeo.nic.in/, accessed 9 September
2013).
Hueb J (1985). Macromedicion. Lima, Peru, Panamerican Centre for Sanitary Engineering and Environmental Sciences (CEPIS) - Panamerican
Health Organization (PAHO).
Jan D, Brikké F (1995). Making your water supply work - Operation and Maintenance of small water supply systems. The Hague, The Nether-
lands, IRC International Water and Sanitation Centre (Occasional Paper Series, No. 29; www.irc.nl, accessed 18 September 2013).
Liu Z et al. (2012). Condition Assessment Technologies for Water Transmission and Distribution Systems. (http://nepis.epa.gov/
Exe/ZyNET.exe/P100E3Y5.TXT?ZyActionD=ZyDocumentClient=EPAIndex=2011+Thru+2015Docs=Query=Time=End-
Time=SearchMethod=1TocRestrict=nToc=TocEntry=QField=QFieldYear=QFieldMonth=QFieldDay=IntQFieldOp=0Ex-
tQFieldOp=0XmlQuery=File=D%3A%5Czyfiles%5CIndex%20Data%5C11thru15%5CTxt%5C00000004%5CP100E3Y5.
txtUser=ANONYMOUSPassword=anonymousSortMethod=h%7C-MaximumDocuments=1FuzzyDegree=0ImageQuality=r75g8/r75g8/
x150y150g16/i425Display=p%7CfDefSeekPage=xSearchBack=ZyActionLBack=ZyActionSBackDesc=Results%20pageMaximumP-
ages=1ZyEntry=1SeekPage=xZyPURL, accessed 9 March 2013).
Ragsdale and Associates. New Mexico Water Systems Operator Certification Study Guide. United States of America, Utility Operators Certifi-
cation Program NMED Surface Water Quality Bureau (http://www.nmenv.state.nm.us/swqb/UOCP/index.html, accessed 18 September 2013).
Table 8 Selected categories of staff involved in OM of water transmission
mains and respective references to sample job descriptions
SO1, SO2, ST3, ST4, ST5, AS1, AS2, AS4, AS5, TS4, TS5, TS6, OP2, TS12, TS14, TS11, SO1,
SO2, ST3, ST4, ST5, AS1, AS2, AS4, AS5, TS4, TS5, TS6, OP2
Main categories of staff involved in OM of water
transmission mains (see generic job descriptions in Part 3)

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FACT SHEET 5: SLOW SAND FILTRATION PLANTS
DESCRIPTION
Water treatment through slow sand filtration combines biological, chemical and physical processes (Figure 9). The princi-
ple of slow sand filtration is to make the water go slowly through a thin layer of microorganisms (“schmutzdecke”) devel-
oped on the top of the filter bed and then through a bed of sand. While the particulate suspended matter is filtered out, the
schmutzdecke feed on bacteria, viruses and other organic matter in the water. The filtered water goes through a layer of
sand and supporting gravel and is finally collected by an underdrainage conduct. In summary, while raw water slowly enters
the filter through an inlet, an outlet leads the treated water from the underdrainage system to a service reservoir and from
there to the distribution mains.
Normally, the sand filter is covered with raw water with a depth of 1.0–1.5 m. The average velocity of the water is normal-
ly within 0.1–0.3 m/hour and the flow should be continuous. Filter reservoirs are normally made up of concrete, bricks, fer-
rocement, etc. To facilitate maintenance actions, at least two filters are needed: while one filter is serviced, the second can
be in operation. A weir accomplishes the purposes of maintaining a minimum water depth within the filter box, aerating the
outgoing water and rendering the operation of the filter independent of fluctuations in the water level in the treated water
reservoir (Figure 9).
For poor quality raw water (turbidity 10 mg/l), it is recommended that the slow sand filtration is preceded by pre-
treatment through, for instance, up-flow roughing filtering. Although the effluent water from a well-operated and well-
maintained slow sand treatment plant is practically free from pathogens, the water may be chlorinated after filtration to
ensure an adequate concentration of free-residual chlorine to prevent recontamination while in the piped distribution
system.
The main elements of a slow sand filtration process include the following:
• A supernatant with a depth of 1.0–1.5 m, which provides the pressure that forces the water through the filter;
• A bed of filter medium (sand) with a thickness of 0.6–1.2 m responsible for the basic treatment of the water;
• An under-drainage collector, which supports the filter medium and collects the filtered water;
• Control valves that control the rates of flow and water levels throughout the treatment process.
In many developing countries, especially for small installations, slow sand filtration is normally the simplest and most efficient
method of surface water treatment.
• The operation of the filter is determined by the filtration rate. The latter is controlled by regulating a valve at the
effluent outlet;
• The control of effluent water is greatly helped by a bulk flow meter measuring the flow rate of the filtered water.
Figure 9 A slow sand filtration process

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Where costly meters are not available, the measurement of the water level over the weir may be a good alternative to
direct flow measurement;
• The inflow is controlled by an automatic control valve (or manually if this is not available) to ensure that the head of
water in the supernatant reservoir remains constant;
• In case of excessive algal growth, pre-treatment with micro-strainers may be a good option to control them. Another
alternative (more expensive) is to cover the filters to avoid the incidence of sunlight. Chlorinating the raw water or
applying copper sulphate are more radical methods to control algae growth;
• Take samples of raw and filtered water at defined time intervals for analysis;
• Measure regularly the inlet and outlet heads. This will provide the measurement of the head loss, which is required for
regulating the flow and maintaining the filter;
• Keep a logbook with precise information on the OM activities performed either regularly or as an emergency.
• Clean the filter beds, either mechanically or manually. The sludge can be used by farmers for dressing their land. The mixture
of sand and organic matter is suitable especially for conditioning heavy clay soils;
• Clean the filter structure and its surroundings;
• The filter should be cleaned when the head loss reduces considerably the filtration rate. This is determined through
monitoring the head loss between the inlet (water surface on the filter) and outlet (water surface on the weir);
• After about twenty to thirty scrapings of the filter, the depth of the filtering material will have dropped to its minimum,
requiring that the filter be re-sanded;
• Preventive and corrective maintenance need to be properly conducted on all the support equipment such as raw-water
pumping stations, reservoirs, chlorinators, valves, etc.
• In very cold climates, freezing may occur if the necessary structural precautions are not undertaken;
• The efficiency of treatment may be adversely affected by low temperatures;
• Sudden changes in raw water quality or the existence of certain types of toxic industrial wastes or heavy concentration of
colloids, may affect the effectiveness of the biological filtration;
• Certain types of algae may cause premature choking of the filter, which, in turn, will require frequent cleaning.
BIBLIOGRAPHY
Barrett J et al. (1991). Manual of design for slow sand filtration. Denver, AWWA Research Foundation (http://protosh2o.act.be/VIRTUELE_BIB/
Watertechniek/350_Waterbehandeling/353.1_HEN_E5_Manual_Design.pdf.pdf, accessed 10 September 2013).
Brikké F, Bredero M (2003). Linking technology choice with operation and maintenance in the context of community water supply and sanitation –
A reference document for planners and project staff. Geneva, World Health Organization (WHO).
Huisman L, F.I.C.E. WEW (1974). Slow sand filtration. Belgium, World Health Organization.
Mwiinga G, Setlhare B, Swartz C (2004). Practical experiences at 5 slow sand filtration plants in South Africa. 30th WEDC International Confer-
ence. Lao PDR (http://wedc.lboro.ac.uk/resources/conference/30/Mwiinga2.pdf, accessed 9 October 2013).
Table 9 Selected categories of staff involved in OM of slow sand
filtration plants and respective references to sample job descriptions
SO1, ST03, ST04, ST05, ST06, AS01, AS02, AS04, AS05, OP03, TS12, TS14, OP02Main categories of staff involved in OM of slow sand filtration
plants (see generic job descriptions in Part 3)

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FACT SHEET 6: RAPID SAND FILTRATION PLANTS
DESCRIPTION
A water treatment plant with rapid sand filtration normally
comprises the following phases of treatment:
Pre-treatment
The treatment process may need a stage of pre-treatment,
which may include pre-chlorination, pre-settling with a time
of detention of 2–3 days, storage up to 90 days, pre-fil-
tration, aeration, chemical treatment, micro-strain and
screening (Figures 10 and 11). Such treatment phases are
normally decided on the basis of the raw-water quality and
the desired quality of the effluent water.
Coagulation and flocculation
The objective of coagulation and flocculation is to remove particulate non-settleable solids, especially colloids, as well as
colour from the raw water. Coagulation and flocculation comprise the following stages of treatment: addition of a continu-
ous flow of adequate quantities of chemicals to the raw water and thorough mixing; formation of precipitates that amalgam-
ate the impurities in the water into flocs with a higher density than that of the water; sedimentation.
Coagulation and flocculation are two separated processes. In coagulation, the coagulant containing aluminium or iron
(ferric salt) is mixed thoroughly with the water resulting in the formation of various types of positively charged aluminium or
iron hydroxide complexes. These positively charged particles adsorb onto negatively charged colloids such as colour, clay,
turbidity, etc., through a process of charge neutralisation. In flocculation, the destabilised particles are bound together by
hydrogen bonding forces to form larger particle flocs during which further particulate removal takes place by entrapment
into the flocs. A gentle and constant mixing of the flocs with the water contributes to a better flocculation.
Sedimentation
Following coagulation and flocculation there is a need to proceed with a sedimentation phase to reduce the load of solids
that otherwise would need to be retained by the filters. Horizontal sedimentation basins, typically rectangular, square or
circular in shape are the most common utilised in water supply systems.
Figure 10 Diagram of a rapid sand filtration plant. Source: adapted from Salvato (1972).
Treatment plant of Pouso Alegre, Brazil.
Source: http://www.iconetec.com.br/modules/content/index.php?id=85.

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Rapid sand filters
A rapid sand filter comprises a bed of sand acting as a single medium granular matrix supported on gravel. The distinctive
features or rapid sand filtration compared with slow sand filtration include careful pre-treatment of raw water to effectively
flocculate the colloidal particles, use of higher filtration rates with more coarser and uniform filter media to utilise greater
depths of filter media to trap influent solids without excessive head loss.
As indicated above, the treatment of raw water by coagulation and settling to remove as many impurities as possible
is crucial to the effectiveness of the rapid sand filtration process. Not all the flocs are retained at the sedimentation basin.
Some flocs, as well as colour and microorganisms, are carried to the filters. This material forms a mat on top of the sand
that aids greatly in the straining and removal of the remaining impurities. This also causes a rapid clogging of the filters.
Thus there is a need to washing the filters regularly by forcing the water backwards up through the filter at a rate that will
provide a sand expansion up to 40% depending on the water temperature and sand effective size.
A well-operated and maintained rapid sand filtration plant can be expected to remove about 98% of the microorganisms
and practically all the colour and suspended solids from the raw water. However, following the filtration phase, there is a
need to chlorinate the water to make it safer for drinking.
• Develop a plan of daily operation and follow it;
• Monitor the water level at the intake structure from which raw water is drawn;
• Measure the raw water flow into the plant;
• Control the concentration of the coagulant solution in the solution tanks;
• Monitor the filter influent and effluent turbidity with a turbidity meter or laboratory testing of samples drawn from a tap;
• Measurement of head-loss build up in the filter media;
• Check the effectiveness of the diffuser;
Figure 11 A typical rapid sand filtration plant. Source: adapted from Wagner and Pinheiro (2001).

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