Rural water supply and water demand ... - Up To - SOPAC

SOPAC Water Resources Unit
Water Demand Management Project
Rural Water Supply and Water Demand Management
REPORT OF VISIT TO VANUATU
29 August - 4 September 1999
By Harald Schölzel
September 1999 SOPAC Miscellaneous Report 351
The Water Demand Management Project is funded by NZAID through a cash grant to
the South Pacific Applied Geoscience Commission.

[3]
Table of Contents
SUMMARY............................................................................................................................................................................... 4
INTRODUCTION................................................................................................................................................................... 6
ACKNOWLEDGMENT........................................................................................................................................................ 8
WATER DEMAND MANAGEMENT AND RURAL WATER SUPPLY.............................................................. 9
1.1 GENERAL.......................................................................................................................................................................9
1.2 WDM AND RURAL WATER SUPPLY SECTION IN VANUATU...............................................................................10
THE MELE/MELE-MAAT SYSTEM............................................................................................................................13
REFERENCES ......................................................................................................................................................................20
APPENDIX 1: TRAVEL ITINERARY...........................................................................................................................21
APPENDIX 2: MELE-MAAT SYSTEM INVENTORY............................................................................................22
APPENDIX 3: DATA ACQUISITION, MANAGEMENT AND EQUIPMENT................................................27
A. EQUIPMENT FOR LEAK DETECTION AND LOCATION..........................................................................33
Table of Figures
FIGURE 1: THE ISLAND OF EFATE AND THE LOCATION OF MELE ......................................................................................13
FIGURE 2: SCHEMATIC OF THE MELE/ MELE-MAAT WATER SUPPLY SCHEME (ELEVATIONS IN M.A.S.L.)..................13
FIGURE 3: PRINCIPLE OF PARTLY NON-PRESSURISED FLOW IN 150 MM PIPE (ASSUMPTION).........................................14
FIGURE 4: FLOW MEASUREMENTS AT 150 MM TRUNK MAIN, MELE MAAT, VANUATU, 31 AUGUST 1999................16
FIGURE 5: UNSCALED NUMERICAL MODEL OF THE MELE-MAAT SYSTEM (BASED ON PLANS FROM 1985 MADE
AVAILABLE BY RWSS) SHOWING PIP SIZES AND ELEVATIONS.................................................................................17
FIGURE 6: IMPOSED DEMAND ACCORDING TO AN ESTIMATED POPULATION OF 2600 APPLYING ORIGINAL DESIGN
CRITERIA(13.5 L/S AVERAGE FLOW ).............................................................................................................................18
FIGURE 7: STEADY STATE RESULTS SHOWING FLOW THROUGH PIPES AND AVAILABLE PRESSURE IN M .....................19
Tables
TABLE 1: IDENTIFIED WDM TOPICS (ROY MATARIKI, HEAD OF RURAL WATER SUPPLY DEPARTMENT , JUNE
1999) .................................................................................................................................................................................12
TABLE 2: DESIGN PARAMETERS FOR HYDRAULIC ANALYSIS.............................................................................................15
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[4]
Summary
This report summarises the results and recommendations of the first field trip from 29 August
to 4 September 1999, to Vanuatu, in the context of the NZODA-funded Water Demand
Management Project. Its main purpose was to initiate the co-operation and determine the
objectives and activities to achieve them.
Prior to the trip Rural Water Supply Section (RWSS) suggested that work should focus on
general WDM measures as an introduction to RWSS staff to the area. The trip coincided with
the mission of a consultant funded by NZODA to assess training needs in RWSS. Therefore
it was decided to wait until the release of this report before more concrete WDM actions
would be planned. However, in coordination with the consultant it was decided that SOPAC
should start with providing training in hydraulics. It was opted that the best way attachment
way to provide that would be bringing RWSS staff to the SOPAC Secretariat. It was
anticipated that the attachment would be carried out from 14 October to 11 December 1999.
As to the introduction to WDM different options have been discussed concentrating on data
acquisition and access to designed and implemented projects as well as equipment needs,
institutional arrangements and building standards. The following areas need to be
addressed:
• Though RWSS has an extraordinary well-established (hardcopy) filing system it is
deemed necessary that access to all relevant information should be provided
electronically preferably through a customised Geographical Information System (GIS).
• Even though rural water supply schemes are small, hydraulic analysis should be carried
out. Using modern analysis software would also be a first step to adequate data storage.
• RWSS needs to set up a Community Participation Unit or seek assistance from other
agencies (eg Land Use Department) to better involve the community in the planning,
design and implementation process. That seems particularly important against the
background that the community is expected to assume full ownership of the implemented
project with little support from RWSS expected.
• Communities should be given an active part over the entire project cycle and they should
be given a choice regarding the design (eg low pressure versus high pressure, quality (eg
basic treatment and service (standpipes versus individual connections). The buzz word is
Demand Responsive Approach.
• Each implemented project should be handed over to a water committee the community
has formed during the planning, design and implementation process. (Rule: No water
committee -no water project)
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• Though community ownership seems to be the only viable solution some thoughts should
be given whether regular maintenance and minor spare parts (eg washers) should be
provided. This could be supported by a water committee that collects a very modest
connection fee.
• RWSS should purchase essential water supply system monitoring equipment, ie a
portable flowmeter, pressure reader connectable to hydrants and taps, a pressure
transducer to read and log water levels in tanks and reservoirs and basic leak detection
tools, eg listening sticks. (see also Appendix 3 for more details.)
• RWSS need to stiffen building standards and measure system performance right after
project completion.
• RWSS should develop a leakage policy that applies to all systems or at least to all
system implemented from a certain size on (eg population connected). Compliance
should be monitored by rotating equipment between field staff and non-compliance
should trigger remedy actions in coordination with the water committee.
• Though outside the scope of this trip RWSS should re-think current practice of providing
water without looking (or providing) adequate sanitation.
Prior to the trip, RWSS identified the water supply systems villages of Mele/Mele-Maat as a
pilot area. During the trip some WDM measurements could be carried out in the respective
area indicating that the Minimum Night Time Flow was around 6 l/s. Assuming a constant
inflow into the tank of about 8.7 l/s (derived from measurements and calculations) water
losses would amount to about 68 % of the production. Even though it was not possible to
confirm this result with more and longer-lasting measurements (bad weather and equipment
failure due to the bad weather) current 'operation procedures' confirm (artificial) water
shortages (no 24 hour water supply.) These shortages are attributable not only to leakage
but also to massive over-sizing of the system. (Admittedly a problem rather uncommon in the
Pacific.)
• The problem could be solved by installing a flow control valve at the end of 150 mm GI
trunk main.
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[6]
Introduction
In the past, development projects in the water supply sector have mainly concentrated on the
upgrading or extension of existing water supply hardware. This supply-driven approach has
proved to be very costly for both the donor and the receiving country and has not lead to a
safe water supply even for the bigger urban centres in most of the Pacific Islands Countries
(PIC). Most water supply systems operate at the edge of collapse not because that there is
not enough water available at the source of abstraction, but because water supply systems in
PIC lose more water through leakage and wastage than they actually deliver to customers.
The patchy design of these distribution systems render not only the technical design of many
aid projects technically questionable but also makes the management and operation by the
local water authority very difficult. With more pressure on very limited resources, many PIC
have realised that the key towards sustainability lies, not necessarily, in costly infrastructure
extension but more in the sound management of the water supply system. This trend has
been enforced with the appearance of institutional strengthening projects in the water sector,
mainly funded by AusAID, that concentrate on building national capacity rather than giving
away hardware.
Generally speaking, water leakage and wastage are the main reasons for water problems in
Pacific Island Countries and previous initiatives to resolve this problem have been limited to
unsystematic and isolated projects. This often resulted in the only temporary set-up of leak
detection units, instructed and trained over a very limited period by consultants. From time to
time, multi-international donors fund some isolated activity to reduce leakage with little or no
follow-up. Though a good part of the project is aimed at this particular problem of water
conservation water demand management (WDM) stands for much more than that. It is a
holistic approach towards controlling the water supply system and making fully-informed
decisions. It includes preventative maintenance as well as setting up performance-monitoring
devices or the zonation of the system by districts and pressure sub-zones. Economic and
environmental issues influence the degree to which leakage detection program will be carried
out and are part of WDM. After all, water pricing is an important tool for influencing consumer
demand together with Public Awareness Campaigns. In short:
'Water Demand Management involves the adoption of policies or investment by a water utility
to achieve efficient water use by all members of the community. (White, 1998) 1 '
In the past, SOPAC managed and implemented a water demand management (WDM)
project in the Pacific funded by the Republic of China. The current WDM project is funded by
the New Zealand Overseas Development Assistance (NZODA). The current project aims to
implement the recommendations and conclusions of a regional meeting with 25 participants
from 13 countries on Water Demand Management held in Nadi from the 21 st to the 26 th of
June 1999. It comprises Technical Assistance with the assessment of water losses,
generation of 'as-built' electronic maps (inventories), generation of hydraulic network models,
1 White, S., (1998), Wise Water management: A demand Management Manaual for Water Utilities, Institute for
Sustainable Future, Universitty of Technology, Sydney, Research Report No. 86.
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[7]
leak detection, management problems and on-the-job-training as well as training
attachments at the SOPAC Secretariat in Suva, Fiji - a genuine approach to transfer
knowledge.
The WDM project should be seen as supplementing ongoing country initiatives.
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[8]
Acknowledgment
The SOPAC Secretariat thanks NZODA for their financial support to its Water Demand
Management initiative.
The author wishes to thank all staff of Vanuatu Rural Water Supply for their support during
the field mission, especially Mr. Roy Matariki, Head of the Department.
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1.1 General
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Water Demand Management and Rural Water Supply
Traditionally WDM projects focus on urban water supply systems apparently for very obvious
reasons:
• Urban water supplies are run by a more or less professionally-organised agency/ utility
hence there is a defined recipient and partner for any project.
• The size of most urban water supply systems generate significant distribution costs and
in some cases also significant revenues. That allows for relatively straightforward costbenefit-analysis
of WDM measures.
• Urban water supply systems usually, and rather unfortunately, also 'generates' significant
leakage levels making it easier to achieve success.
• Water supply problems in urban areas rapidly affect a large number of people making it
more pressing to the water utility/ Government to overcome or anticipate such problems.
• Influential people, locals or foreigners, usually reside in urban areas and push for
providing an efficient and safe water supply (and sanitation).
• Urban areas usually offer a more receptive audience for public awareness campaigns
since they can be considered pure cash-economies.
Rural water supply systems, in contrast, present entirely different problems:
• They are small often with a design flow lower than 1 l/s.
• Design standards are rudimentary and systems are often fragmented since there is little
control over who's connecting and how the connection is being done.
• They are owned by the community and managed by a water committee (if at all
implemented) which rarely has the expertise, skills and financial resources to do so.
• Running costs are mostly insignificant hence rarely seem to justify complex WDM
measures/ projects.
• Rural water supply means that there are many water supply systems often difficult to
reach.
All these points seem to impede WDM measures and ideas which are more consequently
applied to urban water supply schemes. However, there are important considerations that
WDM should play a bigger role in rural water supply.
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[10]
In general, economies of scale apply to water supply schemes. That basically means that
costs to provide one unit of water to consumers decrease 2 with the amount of units
produced. Hence, it is relatively more expensive to provide water to a person that lives in a
small community than to a city dweller. However, very basic (and often insufficient) design
standards (low design flow, very basic development of water intakes, small pipe sizes, few
control devices, low building standards) provide means to reduce costs for rural water supply
systems. On the other hand this leads in some cases to problems with the water supply from
the very beginning; after all losing e.g 0.5 l/s in the form of leakage out of a system that was
designed 3 to provide 1 l/s average flow means that 50% would be lost. That would certainly
create problems for most village schemes.
Even more important seems to be the fact that in many cases villagers substantially
contribute to their water supply schemes either financially (two-third-one-third principle) or in
the form of (unskilled) labour or both. These investments into safe water deserve the same
protection as that given to urban schemes, if not more. Additionally the perceived lack of
water in village supply schemes leads regularly to applications to extend the systems either
with Government or other donor support. Very little attention is usually given to simply look
into the system and analyse its performance and the reason for any possible underperformance
although many such problems could be avoided through WDM.
Finally, WDM in rural areas finds its justification with the apparent increase of droughts not
as an emergency tool but as a relatively simple preventative means to provide safe water to
the community.
1.2 WDM and Rural Water Supply Section in Vanuatu
The need to further improve the Rural Water Supply Section in Vanuatu has been recognised
widely. There are several studies 4 and projects that detail the problems, re-organisation and
training needs as well as recommend solutions and strategies to overcome them. However,
implementation lags far behind.
2 This principal applies not 'forever' since it usually becomes increasingly expensive to abstract water but this
point may be ignored in the present case.
3 And probably does not yield much more at all because the easiest to access source has been captured for cost
and convenience considerations
4 Eg Montgomery & Watson, 1997 and Mills, 1999 (not yet published). The reader is referred to these reports.
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[11]
During the afore-mentioned WDM workshop, some time was spent on developing an
immediate/medium-term Action Plan. Table 1 lists the topics the Rural Water Supply Section
has identified as their main concern (SOPAC, 1999). This list was used to offer a choice of
activities SOPAC could provide assistance with. After some discussion it was agreed that
work during this mission should concentrate on the Mele/Mele-Maat water supply system as
a pilot project to demonstrate WDM principles and methods regarding data acquisition,
storage and hydraulic analysis.
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[12]
Table 1: Identified WDM topics (Roy Matariki, Head of Rural Water Supply Department, June 1999)
Topic Description of Activity Time frame Responsibility Identified Training
Capital Cost Include in budget to cover for metering on pilot
projects only
Hydraulic Analysis Review current designing and design to
accommodate basic metering
Feb-00 Dept of Water Resources
Next financial year (July 99 - July 2000) Current and probable assistance,
UNELCO, Aid Agencies
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Needs
From SOPAC - for
direction
Data Organising Start collecting data into include budget ASAP Dept of Water Resources Mines Dept with SOPAC
Leakage Control Create community awareness ASAP after approval of budget Dept of Water Resources Maintenance and cultural
awareness unit
Reservoir test Measure flow test Monthly Dept of Water Resources, PWD As above
Pipe locating Through project files Next financial year (July 99 - July 2000) Dept of Water Resources, PWD As above
Pipe locating On-site locating of pipes Next financial year (July 99 - July 2000) Dept of Water Resources, PWD As above
District Metering Identify two pilot projects January 2000 As above Basics
District Metering Locate areas needed to be metered i.e. zoning January 2001 As above Basics
Leakage Policy in
Corporate Plan
Include this into our program for major rural
systems i.e. gravity and pumps
Next financial year (July 99 - July 2000) To persuade Management to provide
Re-engineering Provide policy to cater for the changes Next financial year (July 99 - July 2000) Engineering and formulation unit to
funding
include into design
Seek aid funding for the
specific training
Engineer needs to train
other personnel

[13]
The Mele/Mele-Maat System
The villages Mele and Mele-Maat are situated Northwest of Port Vila on the Island of Efate. The
villages are of semi-urban in nature with a current population of about 2,600. Figure 1 shows their
location as "Mele".
Figure 1: The island of Efate and the location of Mele
The existing Mele/Mele-Maat water supply system (Figure 2)consists of a surface-water intake, a 80
mm PE main from the source to the tank (960 m), two interconnected 120 m 3 tanks, a 80 mm GI
main to Mele-Maat (250 m) and a 150 mm GI/PVC main to Mele (2000 m).
Source:
Elevation: 125 m
Main:
Length: 960 m
Type: 80 mm, PE
Flow Rate: 8.7 l/s
Main:
Length: 2100 m
Type: 150 mm, PE,GI
Tanks:
Storage: 2 x 120 m 3
Elevation: 125 m
Main:
Length: 500 m
Type: 80 mm,PVC, GI
Mele System:
Population: 2000
Elevation: ~ 5 m
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Mele-Maat System:
Population: 600
Elevation:~ 10 m
Figure 2: Schematic of the Mele/Mele-Maat water supply scheme (Elevations in m.a.s.l.)

[14]
The design population for Mele was 2,000 and Mele-Maat 600. Design demand was assumed to be
200 l/c/d. Both systems can be operated independently with no interconnection between them
except the common tank they rely on. Inflow into tank has been measured and calculated and is in
the range of about 8.7 l/s and can assumed to be constant over time.
Currently the system experiences problems with providing water over 24 hours. Flow measurements
(Figure 4) at the 150 mm main pipe to Mele indicate that the Minimum Night Time Flow (MNTF) is
about 6 l/s. That suggests that leakage amounts to about 68 % of the daily production in the Mele
system alone. Further flow measurements were not possible because of equipment breakdown due
to bad weather.
The current water supply problems are attributable to the high level of leakage as well to a gross
over-design(!!!) of the entire system. The Mele system has been designed for a maximum flow of
30 l/s, the Mele-Maat system for 9 l/s 5 . That resulted in pipe diameters far to big to allow for a
pressurised pipe flow and a rapid drain-out of the tank. The pipe slope over the first, say, 150 m after
the tank is about 70 degrees accelerating the water that leaves the tank to an extent that creates an
open channel flow within the pipe. That on the other hand avoids that the full head between the tank
and the Mele system (65 m - 5 m = 60 m) becomes effective. Figure 3 describes the problem.
Pressurised flow
Water surface, no pressurised flow
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Effective Head = ?? m
Theoretical Head = 65 m
Figure 3: Principle of partly non-pressurised flow in 150 mm pipe (assumption)
This assumption was indirectly confirmed by flow measurements 6 . This problem can be resolved by
installing a flow control valve in the flat part of the 150 mm main right after the slope 7 .
5 It is a mystery where these design criteria have been derived from.
6 The portable flowmeter could not detect valid condition to take measurements. This usually means, after excluding other
error sources, that the flow not pressurised or too turbulent - in this particular case probably both.
7 Currently the flow is regulated by a gate valve at the outlet of the tank effectively limiting the outflow of the tank but
aggravating the described pressure problem.

[15]
A full hydraulic analysis based on the original system design and the measurements have been
carried out. Table 2 summarises the applied design criteria. These more modest criteria follow
standard procedures and are much more in line with the actual production of the source: 8.7 l/s as
production versus 6.02 l/s average flow, 7.82 l/s max. average daily flow 8 .
Table 2: Design parameters for hydraulic analysis
Village Mele Mele Maat Total
Population No. 2000 600 2600
Demand Daily [l/capita/day] 200 200 400
Total Demand [l/day] 400000 120000 520000
m3/day 400 120 520
Average Flow [l/s] 4.63 1.39 6.02
[m3/hour] 16.67 5.00 21.67
Daily Peak Factor [-] 1.30 1.30
Max Aver. Daily Flow [l/s] 6.02 1.81 7.82
Hourly Peak Factor [-] 2.40 2.40
Max.Hourly Flow [l/s] 14.44 4.33 18.78
Even the max. hourly Flow of 18.78 l/s does not come anywhere near the 37.8 l/s flow applied in the
original design.
The results of the hydraulic analysis have been summarised in Figure 5 to Figure 7 and Appendix 2.
They show that, assuming fully pressurised flow, pressure would be at all times in the range of 55 m
posing a hazard to a rather usually fragile house connection. On the other hand high pressure during
static or semi-static conditions (pipes fill fully during the night) yields a good explanation for the high
leakage levels in the system. However, since it is unlikely that the 150 mm pipe to Mele ever fills fully
the hydraulic analysis provides only limited information unless more is known about the real pressure
levels in the system. It is anticipated that this information can be gathered within the next two
months.
8 This base flow would be used to design the tank applying specific local demand pattern the flow.
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Flow [l/s]
12
10
8
6
4
2
0
[16]
Flow Rate Mele Maat water Supply System, Efate, Vanuatu
Estimated Minimum Night Time Flow: 5.64 l/s
15:30:16 99-08-31
15:46:16 99-08-31
16:02:16 99-08-31
16:18:16 99-08-31
16:34:16 99-08-31
16:50:16 99-08-31
17:06:16 99-08-31
17:22:16 99-08-31
17:38:16 99-08-31
17:54:16 99-08-31
18:10:16 99-08-31
18:26:16 99-08-31
18:42:16 99-08-31
18:58:16 99-08-31
19:14:16 99-08-31
19:30:16 99-08-31
19:46:16 99-08-31
20:02:16 99-08-31
20:18:16 99-08-31
20:34:16 99-08-31
20:50:16 99-08-31
21:06:16 99-08-31
21:22:16 99-08-31
21:38:16 99-08-31
21:54:16 99-08-31
22:10:16 99-08-31
22:26:16 99-08-31
22:42:16 99-08-31
22:58:16 99-08-31
23:14:16 99-08-31
23:30:16 99-08-31
23:46:16 99-08-31
0:02:16 99-09-01
Figure 4: Flow measurements at 150 mm trunk main, Mele Maat, Vanuatu, 31 August 1999
Time
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[17]
Figure 5: Unscaled numerical model of the Mele-Maat System (based on plans from 1985 made available by RWSS) showing pip sizes and
elevations.
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Figure 6: Imposed demand according to an estimated population of 2600 applying original design criteria(13.5 l/s average flow)
[18]
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Figure 7: Steady state results showing flow through pipes and available pressure in m
[19]
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[20]
References
Montgomery & Watson (1997), Master Plan Studies for Vanuatu & New Zealand
Mills, G. (1997), Training needs of the Department of Geology, Mines & Water Resources,
New Zealand
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Sunday, 29 August - Suva - Nadi - Port Vila
[21]
Appendix 1: Travel Itinerary
Saturday, 4 September - Port Vila - Nadi - Suva
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[22]
Appendix 2: Mele-Maat System Inventory
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[23]
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[24]
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[25]
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[26]
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[27]
Appendix 3: Data Acquisition, Management and Equipment
This section has been provided by Malcolm Farley, WHO Consultant and Specialist in
Water Demand Management.
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A. General
Operational Data Management (DM) involves
• - the acquisition of data
[28]
• - the transmission of data from local sites to operations
• - the archiving and presentation of data and reports
Such a system requires;
• - a sensor, for data gathering at source
• - data logging equipment, for local site storage
• - a communication system, for transferring data to the operator
• - software, for archiving and presenting data
Sensors
A typical monitoring system will include sensor capacity and interface leads for a range of DMA
meters and pressure monitors;
• - digital and analogue (e.g. 4-20mA, 0-1V) output
• - specific pulse heads for helix meters (e.g Kent PD100 pulse disk bidirectional sensor)
• - other proprietary sensors (HRP, LRP, reed switch, BPG20)
• - optical sensors
• - magnetic sensors
• - pressure and depth transducers
Data Capture
Data capture requires the use of pulse generators, pulse counters and data loggers (portable or
with telemetry) to capture data from the DMA meter.
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Pulse generators.
[29]
These are units attached to the register of a mechanical meter to provide a pulse output, in
effect creating an electromechanical meter. Kent Meters supply the LRP (10 pulses/rev) and
HRP (100 pulses/rev) units which are attached to the range of their helix meters. They are solid
state units which have replaced the Kent PU10 and PU100. Wessex Electronics also supply a
solid state unit, the "Metermate", which will interface with any of the Kent helix meter range and
any data logger.
Pulse counters/low cost data loggers
These units are usually low cost single or dual channel data loggers used to record pulse
output signals. Their main use is as a temporary installation data logger to record night flows
over several nights as an indicator of leakage prior to a full data logging exercise. They are also
suitable for household and non-household demand logging. Some loggers can be mounted
directly onto helix meters, eliminating the need for a pulse generator.
An outline specification for this type of logger is as follows;
• logging interval from 6 seconds to 60 minutes
• 120 days memory at 15 minute intervals
• submersible to IP68
• temperature -10 deg C to + 60 deg C
• digital input to support;
• pressure input facility to support;
• RS232 interface
range of mechanical helix meters
electromechanical insertion probes
EM insertion probes
contact closure pulse units
electronic pulse units used with a range of mechanical
meters
0-25 bar for distribution monitoring sensors
0-350 millibar for reservoir depth sensors
range of electrical inputs
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Data loggers
[30]
Data loggers are used by all water companies to regularly monitor DMA flows on a 24-hour
basis. They are dual or multi-channel, designed for permanent installation if required.
An outline specification for this type of logger is as follows;
• - logging interval from 1 second to 24 hours
• - 380 days memory at 15 minute intervals
• submersible to IP68
• shock proof from1.0m drop
• temperature -10 deg C to + 60 deg C
• digital input to support;
• pressure input facility to support;
• communications;
• battery life 10 years (lithium chloride)
• alarm capacity
range of mechanical helix meters
electromechanical insertion probes
EM insertion probes
contact closure pulse units
electronic pulse units used with a range of mechanical
meters
0-25 bar for distribution monitoring sensors
0-350 millibar for reservoir depth sensors
range of electrical inputs
software selectable,
local via RS232 interface, telemetry options
It should be noted that some manufacturers supply data loggers with a sufficiently high
specification to serve as both pulse counters and permanent data loggers. It is recommended
that practitioners use the specifications above as a guide for selecting from a manufacturer the
data logger suitable for the purpose.
All logger types should be compatible with the range of European and North American
flowmeters which are now being used by the UK water industry for DMA monitoring. They
should able to receive digital and analogue signals so that they can also be used for pressure
monitoring and level sensing, and with temporary insertion/clamp-on meter installations.
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Communications
Data is communicated from site by;
[31]
• site interrogation via a laptop or palmtop (e.g. Psion) computer
• return of the data logger to the office for PC interrogation
• telemetry, either via PSTN, GSM or Paknet
Telemetry data logger
Telemetry loggers should be capable of linking to a range of communication systems. In
addition to the data capture specifications listed in 3.3.2, they should have the option of;
• internal PSTN modem
• GSM (Cellnet or Vodaphone) module
• Paknet radio-pad
An initiative by one water company (reported in "Water Bulletin" - January 1998), involves
connection via Vodaphone's wireless data network, using 1200 "Paknet Radio-Pad"
connections (modem equivalent). It is claimed that purchase and installation of the radio
network will cost 10% of a fixed line system, which can cost up to £3000.00 for a single
connection. Line rental is also less (50% of a standard telecom line). The monitoring system
uses ABB Kent-Taylor meters and a mix of Radcom and ABB data loggers. The antennae are
housed in polyethylene pillars.
Individual manufacturers can provide more detailed specifications for their monitoring
equipment. Leading manufacturers are listed in Appendix 1.
Monitoring software and information systems
Software is required to arrange logged data into a form where it can be used for analysing and
interpreting total night flow losses in each DMA.
Software for calculating and displaying total night flow losses is usually provided by logger
manufacturers. Companies either use manufacturers' software, commission consultants, or use
their own in-house facilities for writing software for leakage reports and for DMA management.
Typical information required for these reports are;
• DMA details
• DMA night flow data and aggregated flows
• total night flow losses in each DMA
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• estimated leakage and priority DMAs
• company leakage figure
• historic burst records
• repair times and cost
[32]
DMA data identifies unreported bursts, from sudden changes in volume, and cumulative
leakage, from a combination of small bursts and weeping joints and fittings.
In a telemetered DMA system night flow data can be received and analysed regularly. This
enables changes in the night flow of each DMA to be quickly identified, reducing awareness
time. When compared with previous readings and with other DMAs, it enables the leakage
control team to prioritise inspection. The logger software typically contains an "error table"
which identifies those DMAs where night flows have increased above a pre-set alarm level.
The leakage control team is able to scan the error table daily to identify unreported bursts, or in
response to poor pressure complaints to confirm a reported burst.
Software should be Windows-based, and should provide facilities for graphing and report
generation to prioritise work.
[MR351 - Schölzel]

[33]
A. EQUIPMENT FOR LEAK DETECTION AND LOCATION
A Review of the Equipment
Equipment Comments / Application Limitations
‘Basic’ Listening
Stick
‘Electronic’
Listening Stick
Electronic ground
microphone
Electronic ground
microphone with
sound frequency
filters
Rudimentary sounding of SVs,
FHs, MSTs etc.
General sounding of SVs, FHs,
MSTs etc. Better than ‘Basic’
Stick due to sound
amplification. Is sometimes
used to confirm ‘best leak
sound’ position after
correlation.
More sensitive than the
electronic stick, generally used
to confirm ‘best leak sound’
after correlation, powerful
enough to listen to leak sounds
through ‘made roadways’. Can
be used for general sounding
with a probe screwed into
microphone.
As sensitive as the ground
microphone with the added
advantage of the inspector
being able to adjust filters and
remove some unwanted
sounds. Generally used to
confirm ‘best leak sound’ after
correlation. Powerful enough
to listen to leak sounds through
‘made roadways’. Can be used
for general sounding with a
probe screwed into
microphone.
[MR351 - Schölzel]
Some smaller leak sounds
may go undetected (good
ear required by inspector).
Few limitations, generally
useful part of the
inspectors ‘tool kit’.
Better than ‘Basic’ Stick,
not as good as ground
microphone (see below).
More ‘cumbersome’ to
use than listening stick.
Some inspectors do not
like to use microphones,
they prefer the electronic
stick.
More ‘cumbersome’ to
use than listening stick.
Some inspectors do not
like to use microphones,
they prefer the electronic
stick

[34]
Equipment Comments / Application Limitations
Acoustic
Detection Loggers
‘Stores’ sounds within the
distribution system usually
between 02:00 and 04:00.
Loggers are set up and
downloaded using a PC. Leak
sounds are identified by the
‘range’ of sounds recorded by
the logger. Useful for areas
where normal leak location
activities cannot be used.
Step Test Unit Mobile Advanced Step Tester
(MAST) system. Used for
remote monitoring of flows
whilst carrying out step tests
within distribution networks.
Allows almost instant results
of valve closure leading to
minimum disruption to
customers. Leak location
activity can be carried out
quickly rather than waiting for
‘office based’ analysis of step
tests using data loggers.
Leak Noise
Correlators -
various
Can also be used for remote
monitoring of pressure during
valve closure (critical node
monitoring whilst setting up
PMAs or DMAs).
Used for general ‘surveying’ of
lengths of main for leak sounds
followed by more accurate leak
location. Various ‘models’
available from easy to use
menu driven machines to PC
controlled FFT machines for
more ‘difficult’ jobs. Sensitive
enough for quiet leak sounds,
can survey long lengths of
main rather than manual
sounding of individual valves.
PC based correlator can be
used for other applications
[MR351 - Schölzel]
Does not locate actual
leak position, can give
identification that leak is
taking place.
Valve closure required,
may cause discoloration /
water quality problems.
Difficult to use during day
as some disruption to
supplies will take place
(unless areas are ‘back
fed’ when valve closure
takes place). Step tests
need to be planned to gain
best results.
Very accurate when all
data inputs can be
guaranteed. Limited to
the fact that main
material, length,
velocities can cause errors
in calculations if not
accurately entered. A
reasonable level of
inspector training, skill
and experience is required
for use. The better the
information the better the
result.

[35]
Equipment Comments / Application Limitations
Hydrogen gas
detection method
loggers. PC’s can be loaded
with ‘mobile’ graphical
information systems providing
inspectors with distribution
system drawings.
Identifies leak position by
detecting the location of
hydrogen gas which has been
introduced into the water
supply. The hydrogen gas
(carried in 95% nitrogen) rises
to the surface above the leak
position. Due to the small size
of hydrogen molecules the gas
can permeate concrete, asphalt
etc. Provides accurate leak
location as the gas rises above
the break in the pipe.
‘Flexi Trace’ Enables non-metallic pipework
to be located by the insertion
of a flexible ‘wire’. Once
inserted in the pipe a signal is
induced either at the leading
point of the trace wire or
throughout its length. This
signal can then be traced using
a cable avoidance tool.
Pipe & cable
locating /
avoiding tools
Other pipe tracing
equipment
Used for locating cables and
pipework.
A ‘vibrating’ sound can be
induced in the pipe to be traced
via equipment attached to a
[MR351 - Schölzel]
Best suited to locating
leaks on smaller pipes
(ideal for difficult supply
pipe leak locations).
Pipework is de-watered
by the introduction of the
gas. Gas needs to be
introduced by using either
a boundary meter box and
forcing the gas toward the
property or closing the
boundary connection and
introducing the gas
through the customers
internal stop tap. Can
take some time to set up
and for gas to rise to
surface for detection.
The trace wire has to be
inserted into the bore of
the pipe, leading to a
possible contamination
risk. Hygiene care needs
to be taken when using
the trace. Trace will not
pass sharp bends or Tee’s.
When obstructions are
met the pipe has to be
excavated, the pipe cut
and trace re-inserted.
Not suitable for plastic
pipes unless ‘flexi’ trace
is used.
Can get complaints about
noise in pipes when in
use. Some argument

Leak detection equipment costs
[36]
Approx. Costs
£ F$
Step test units
Biwater Spectrascan Aqualink 4600 13800
Palmer Mobile Advanced Step Test unit (MAST) 6000 18000
Wessex Electronics Tele-link/Tele-log
Leak localisers
4500 5500 13500 16500
Biwater Spectrascan Spectralisten 6000 18000
Palmer Aqualog 40/"Aqualog50" 7000 21000
Sewerin (PCL) SePem
Leak location equipment
Simple sounding stick
4500 13500
Palmer ST 20 Commercial Industrial Gauges (wooden)
Electronic sounding stick
80 240
Biwater Spectrascan Stethaphone 280 840
Fuji Tecom FSD-7D 280 840
Palmer LS 5 400 1200
Sewerin (PCL) Stethophon
Ground microphone
195 225 585 675
Biwater Spectrascan (for use with Aquacorr) 750 2250
Fuji Tecom HG-10 1200 3600
Palmer MK5 1700 5100
Sewerin (PCL) Aquaphon Memotech
Leak noise correlator
2000 6000
Biwater Spectrascan Aquacorr 6350 19050
Palmer MicroCorr 6 12000 14000 36000 42000
Palmer MicroCall (Portable PC based correlator) 13500 16000 40500 48000
Palmer Corralog Leak Manager
(incorporates flow/pressure loggers and step test unit and ground microphone)
6000 18000
Primayer Eureka 5000 15000
Sewerin (PCL) SeCorr 3 6000 6500 18000 19500
Sewerin (PCL) SeCorr 4 (portable PC based) 9000 11000 27000 33000
[MR351 - Schölzel]