Annotation of the project

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JUNIORSTAV 2011
3. Water Management and Water structures
RISK ANALYSIS METHODOLOGY AND ITS IMPLEMENTATION ON CONTINUOUS AND
INTERMITTENT WATER SUPPLY SYSTEMS
Alayoubi Mzayan 1 , Valešová Martina 2 , Tuhovčák Ladislav 3
Abstract:
The paper presents the methodology of risk analysis for public water supply systems, which is a systematic predefined
process to identify, assess and evaluate the hazards and undesired events in existing water supply systems. The
methodology is associated with a simple and practical software tool that analyses the risk and interprets the
consequences as a clear form to support risk management and decision-making procedures.
The WaterRisk methodology and software tool have been implemented and tested on many simple and complex
water supply systems in Czech Republic with continuous supply patterns. The paper discuses the results of these case
studies and suggest the required development of the software tool that should be done to deal with the intermittent
supply also.
Key words:
Hazards, intermittent, risk analysis, undesired events and water supply.
1 INTRODUCTION:
Risk management is to assess, control, and minimize risk to acceptable levels in the entire water supply system
after subdivided it into subsystems (Source, Treatment system, and distribution and plumbing networks) from source to
tap.
WaterRisk project carried out by Institute of Municipal Water Management / BUT; Local water supply Utility, and
National Institute of Public Health in Brno, Czech Republic during 2006-2010. This project developed risk analysis
methodology and a software tool in the frame of the HACCP methodology (Hazard Analysis at Critical Control Points)
to achieve high level of drinking water quality and safety.
Risk analysis methodology is a systematic pre-defined process to identify, assess, and rank the weaknesses and
shortcomings of an existing water supply system as a first step of risk management of that system, hazards that may
either affect water quality or interrupt the service and the undesired events that are consequences of the hazards will be
specially focused on.
Intermittent water supply is not accebtable in Czech Republic, only temporary emergency supply is allowed under (
§ 109 law 254/2001Sb. About water), so that the intermittent supply is considered as undesired event that related to
distribution system’s section in the catalogue of UEs, more details will be presented.
2 RISK ANALYSIS METHODOLOGY :
2.1 Terminology of risk analysis:
� Undesired event UE:
It is the state when an element (system, part, or product) loses its required property or ability to fulfil the required
function in specific conditions.
� Hazard:
It is a potential source (reason) of the UE.
� Risk:
The common definition of the risk is the combination of the frequency, or probability, of occurrence and the
consequence of an undesired event.
1
Mzayan Alayoubi, Ing., Brno University of Technology, Civil engineering faculty, institute of Municipal water Management, Brno 60200, Žižkova
17, AlayoubiM@study.fce.vutbr.cz
2
Martina Valešová, Ing., Brno University of Technology, Civil engineering faculty, institute of Municipal water Management, Brno 60200, Žižkova
17.
3
Ladislav Tuhovčák, Ing, CSc, Brno University of Technology, Civil engineering faculty, institute of Municipal water Management, Brno 60200,
Žižkova 17, Tuhovcak.l@fce.vutbr.cz

JUNIORSTAV 2011
3. Water Management and Water structures
For the purposes of water supply system risk analysis, that definition was accepted, developed, and expressed as
follows:
R=P*C (1)
While:
R stands for the risk.
P stands for probability of occurrence of UE.
C stands for consequence of the event.
� Risk analysis RA:
RA is a structured process identifying both the probability of occurrence of an undesired event, and the extent of
adverse consequences arising from the event, it tries to answer the following three principal questions:
What can go wrong? (UE and hazard)
How likely is it? (Frequency analysis)
What are the consequences? (Consequence analysis)
2.2 The main principals of the methodology:
Currently there are many methods to analyse risk in water supply systems. While choosing the appropriate method,
many considerations should be taken in to account, The method should be suitable and sustainable for the existing
system, It should offer results in forms that present clear comprehensive of the risk.
Based on those and other considerations, the developed methodology has been formulated, the main principals of it
are:
1. It is suitable and sustainable for existing water supply systems,
2. It offers the results in forms that support decision-making system,
3. It is adaptable and explicitness,
4. It is supported by a simple and practical software tool that deals with the whole components of the water
supply system,
5. The evaluation procedures are objective and clear,
6. Distinguishes between simple and complex systems,
7. Interprets the results in a context,
8. Implements qualitative analysis techniques.
2.3 Risk structuring:
It is important to clarify what will be analyzed (part x unit); which sort of WSS it is (simple x complex), and what
level of details will be distinguished. After defining and describing water supply system, the next analysis’s step can be
performed.
Water supply system is divided into three subsystems that are analyzed separately:
1. Water source,
2. Water treatment plant,
3. Water distribution (accumulation, pumping, and distribution)
The analysis distinguishes between two types of systems – simple and complex.
Criteria Limitation Studied system
Population
0 up to 2000 Simple system
2001 and more Complex system
The number of
connections
Network’s length
The volume of the
consumed water (m3/year)
Complexity of the used Simple system
0 up to 500 Simple system
501 and more Complex system
0 up to 10000 Simple system
10001 and more Complex system
0 up to 75000 Simple system
75001 and more Complex system
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technology for water
treatment
System is without water treatment plant, or
with an aeration, or carbon dioxide removing
treatment technology.
Complex system
Any more complex treatment technology
than that specified for the simple system exist in
the system, so it considered complex.
Table.1. Simple and complex systems criteria
2.4 Generic framework of risk analysis of water supply systems:
Input data Catalogue of
hazards and risk
System
description
Questionnaire
Risk
Influencing Factors
Vulnerability
UE_345: Intermittent water
supply
2.5 Hazard analysis:
2.5.1 Hazard identification:
influencing actors
Fig.1. Generic framework of risk analysis of water supply system
2.5.2 The catalogue of hazards and risk influencing factors:
2.5.3 Hazard estimation:
2.6 Risk estimation:
Database of
WSS elements
Frequency
analysis
Consequences
analysis
2.6.1 Undesired events identification:
In this methodology, 58 undesired events have been defined, they are:
1. 11 UEs for water source,
2. 6 UEs for treatment plant,
3. 41 UEs for distribution system + UE_345.
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Catalogue of
undesired events
Undesired event
R = P x C
Database of risk
reducing measures
JUNIORSTAV 2011
3. Water Management and Water structures
Hazard
identification
And
Undesired
Events
identification
Risk
estimation
Risk
evaluation
Risk
reduction

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3. Water Management and Water structures
2.6.2 Undesired events catalogue:
UE catalogue is a specific list of undesired events or failures of particular parts of the WSS with interaction to the
formerly identified hazards and risk-influencing factor that may cause them.
UE is defined for a certain part of the system; there may be more than one UE for each part and each of them must
be properly described (what, when, how –scenario).
The content of the catalogue is generated by the software application according to the type of WSS, identified
hazards, and the analysed part.
2.6.3 Frequency analysis
The major problem is always how to calculate or estimate the values of C and P under uncertainty - lack of data,
insufficient historical records and/or unreliable data, uncertainty of failure detection.
This problem was effectively solved, by using frequency instead of mathematical probability of occurrence of UE,
based on some chosen factors or indicators, and on limits of categories.
In risk analysis of water supply system, the analysis proceeds bottom-up-ward, that mean it begins with choosing
the element from the lowest level of the system for which enough information is available. Several tables are created to
describe the different failure modes that may occur, and then the consequence of the failure for each of them is
considered as a failure mode when the consequences are analyzed at the next higher level.
Frequency of occurrence Risk factor
No failure 0
low 1
Moderate 2
high 3
Unevaluated factor N
Table.2. Risk factors
After all main factors for UE are defined; Sc is set by summing all risk factors, and then SCMAX can be
determined by:
SCMAX = 3 x n (2)
While n stands to the number of main factors for the UE, it does not take into account the unevaluated factors.
The rate SC /SCMAX sets the probability
The rate SC /SCMAX Reference of the probability
SC /SCMAX = 0 P0- zero probability
0 < SC /SCMAX ≤ 0,30 P1- unlikely ( < 1x year)
0,30 < SC /SCMAX ≤ 0,60 P2 – probable ( 1x week up to year)
0,60 < SC /SCMAX P3 – certain ( 1 x week and more)
Table.3. probability
2.6.4 Hotspot:
Hotspot is an indicator for the dominant risk factor, which has extreme significant, and influence than other existing
factors; it may be one Hotspot for each UE or more than one.
Hotspot should have high risk factor with probability P3.
2.6.5 Consequences analysis
The consequences are divided into four categories depending on their characters:
1. Health consequences, CHEALTH;
2. Economic consequences, CECON;
3. Social consequences, CSOC;
4. Environmental consequences, CENV;
5. In addition to one common value CTOTAL
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While:
CTOTAL = max (CHEALTH, CECON, CSOC, CENV) (3)
To evaluate each of the four consequence categories, certain dimensions have been described:
Verbal rating scale of consequence Rating scale
high C3
Moderate C2
low C1
No failure C0
Unevaluated category N
Table.4. Rating scale of the consequences
2.6.6 Risk matrix
Three levels of risk are distinguished:
1. None or negligible risk (very low K1, low K2);
2. ALARP, as low as reasonable possible risks (average K3);
3. Intolerable risk (high K4, extreme high K5)
Evaluation level
C1
consequences
C2 C3
probability
3 INTERMITTENT WATER SUPPLY
P1 K1 K2 K3
P2 K2 K3 K4
P3 K3 K4 K5
Fig.2. Risk matrix
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JUNIORSTAV 2011
3. Water Management and Water structures
3.1 General description.
Drinking water systems that are supplied by water twenty-four hours a day, seven days a week are called
continuous supply systems.
In some countries, it is not practically possible to supply drinking water systems as a continuous pattern, due to
insufficient water sources, polluted available raw water with no financial ability to treat it, technical problems in the
system, generally, a period of eight hours or less is considered adequate to supply the network with drinking water and
that is called intermittent water supply.
In intermittent water supply system, consumers use individual roof or ground tanks to store water during supply
hours, consumers store as much water as possible to provide their daily needs during the water interruption hours, so the
water consumption is not restricted only by the operation pressure in the network, but also by capacity of the roof
storage tanks.
Intermittent water supply has many negative side effects such as:
1. Low pressure in some zones of the network,
2. System doesn’t operate as designed,
3. Inconvenience for consumers,
4. Consumers should pay for pumping, and storage tanks.
5. Increasing water consumption, because of storing as much water as possible in supply hours.
6. High probability of contamination, due to low or zero pressure in some areas,
7. Inability to effectively apply water demand management plan on the system.

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3. Water Management and Water structures
8. Inability to effectively apply water supply management plan on the system.
9. Higher doses of chlorine are needed,
In developing countries, intermittent water supply is acceptable and common, even if it has many negative side
effects, while in developed countries it is not acceptable.
3.2 Intermittent water supply in Czech Republic conditions:
Public policy of water supply systems and sewage systems in Czech Republic is under §1 paragraph 2 law
no.274/2001Sb., it only considers the constructions, the infrastructures, and the establichment and operation of water
systems for public consumption and sewage systems.
In Czech Republic insufficient water supply can only be temporary ( § 109 law 254/2001Sb. About water).
1. Emergency supply:
It is related only to the extraordinary situation – temporary water shortage.
Eventually deterioration in water quality, and limitation or restriction in withdrawal permissions from surface or
underground water source, leads to serious public policy risk, just necessary urgent interruption period for adjust or fix
the errors is possible in public policy under water law in Czech Republic.
2. Intermittent supply:
It is long-term interruption supply in water system (week to month), when water is supplied less than 24 hours a
day, and/or less than 7 days a week.
Normally, In Czech Republic drinking water is supplied with a continuous pattern, households aren’t equipped with
roof tanks or pumps to accumulate water, so they may use bathtubs, pails, cans, jars... etc. to collect water to provide
their daily needs of water during the water interruption hours, that will affect water’s quality and complicate next
manipulations, so in Czech Republic intermittent water supply is not acceptable.
Research team of WaterRisk project decided to insert the intermittent water supply as an undesired event that
related to distribution system in the catalogue of UEs.
3.3 Intermittent water supply as an undesired event
� The undesired event title: Intermittent water supply.
� Code: NS_345
� The involved subsystems:
1. Underground water sources.
2. Surface water sources.
3. Pumping stations.
4. Supply and distribution pipelines.
� Affected part : Water supply network.
� Risk type: quantity
� The required data
Physical sightseeing/survey for the objects and
surrounding.
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F1 F2 F3 F4 F5
x x x x
Consultation with the operational techniques. x x x x x
Manipulation’s rules, and the decisions of water
law’s office.
x x
Operating instruction. x x x x x
The local plan of supplied area. x x x x
Summary of precipitations and temperature during
last 5 years.
Quantities of withdrawal water during last 5 years,
monthly audits.
x x
x x x
The volume of produced water / year during last 5 x x x

years.
The changes in water levels/ water tables in
underground water sources during last 10 years.
The records of water levels’ changes in the reservoirs
during last 5 years.
Hydrogeology survey. x
Maps of mining activities. x
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x
x
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3. Water Management and Water structures
Summary of raw water in catchment basin. x x x
Audits of failures. x x
Topology of water supply system. x x
Data of consumption (recorded customers, characters
of buildings, etc...).
x x x
Data of supply electrical energy. x
Table.5. Required data for every factor.
� The related hazards
1.05- Strong wind
1.06- draught
1.09- Global climate change
2.02- Operation manner/ method
2.03- Maintenance
2.09- Inappropriate management with water sources
2.11- Customers / consumers
3.01- Failure in electrical power supply
3.03- Failure in the equipments
3.05- Inappropriate properties of the construction’s materials
3.06- Inappropriate properties of the delivered water
3.12- High operational pressure
3.15- Insufficient hydraulic capacity
3.19- Old materials and changes in their properties
3.21- Bad technical status of the objects, pipelines, and valves
� The risk factors:
1. F1, Insufficient water sources capacity, depletion source - HOTSPOT,
2. F2, Insufficient hydraulic capacity,
3. F3, Bad technical conditions of pipelines, high water leakages,
4. F4, Consumers behavior in network operation period.
5. F5, Relation to other infrastructures.
3.3.1 F1, Insufficient water sources capacity, depletion source - HOTSPOT:
It is related to the following hazards:
1.06- draught
1.09- Global climate change
2.09- Inappropriate management with water sources
The problems that may cause this factor are:
� Long-term changes in the climate of catchment basin that cause decreasing in rainfall or inadequate period of
rainfall (rainstorm),
� Droughts, short-term scarcity of precipitations in catchment basin can cause declining underground water
level, decreasing in river flows and decreasing in source capacity,

JUNIORSTAV 2011
3. Water Management and Water structures
� Change of regime of surface water,
� Increasing in other consumptions in catchment basin,
� Increasing in the demands till exceeding the sources capacity.
3.3.2 F2, Insufficient hydraulic capacity:
Insufficient hydraulic capacity is described as decreasing in the quantity of delivered water, less than the required
amount, and less than the expected theoretical calculation.
The undesired event occures in the case that one consumer or more, who has connection with the network can‘t
receive water with the required quantity nor with the required hydrodynamic water pressure.
It is related to the following hazards:
2.03- Maintenance
2.11- Customers / consumers
3.15- Insufficient hydraulic capacity
The problems that may cause this factor are:
� High water losses
� Increasing demend of water - new supply areas, new industrial objects are achieved,
� Increasing in industrial and agriculture production,
� Increasing in specific demand of high-level of living (swimming pools, gardens), decreasing of tariffs.
3.3.3 F3, Bad technical condition of the network, and high water leakages:
During last years, many simple water supply systems have been evaluated in Czech Republic.
To assess the losses we have many indicators such as :
� VNF, percentage of Non-revenue water,
� VVR, leakages of produced water in the network,
� JUVNF [m3/km/year], leakage unit of Non-revenue water, this one is more predicative,
� EIZ, Water loss economical index evaluates parts of system, where could be significant economic losses
caused by water leakage,
� ILI, Infrastructure Leakage Index,
� VNFP, Non-revenue water in connections.
3.3.4 F4, Consumers behavior in network operation period:
It is related to the following hazards:
2.09- Inappropriate management with water sources
2.11- Customers / consumers
Drinking water is easily accessible and low cost commodity in Czech Repubilc, Therefore the households use
drinking water where they could use rain or grey water.
Changes in the behaviors of the consumers are not expected, there are no serious problems.
Problems appear only during dry summer season because of decreasing in rainfall or inadequate period of rainfall
(rainstorm), and increasing of water demand to use it for potting and for filling swimming pools,
There is sufficiency of drinking water for households, but increasing in water demand for potting and filling of
swimming pools may cause depletion water sources capacity, so water utilities must look for new source or ensure
emergency water supply.
3.3.5 F5, Relation to other infrastructures:
It is related to the following hazards:
1.05- Strong wind,
2.03- Maintenance,
3.01- Failure in electrical power supply.
Water supply is totally depending on electrical energy supply and partly depending on communication and
information systems, which are also depending on electrical energy supply.
Subsystems that depend on electricity:
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Raw water source:
� Technical equipments – pumping.
Treatment water plant:
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3. Water Management and Water structures
� Technological process – aeration, carbon dioxide removing, oxidation, coagulation, homogenization,
flocculation, flotation.
� Chemical management preparation, dosage,
� Pumping.
Distribution system:
� Pumping.
The failure in electrical energy supply could be happened because of:
1. High consumption in summer season because of increasingly using the air conditions.
2. During high temperature, air power plants produce minimum power, so their power substituted with
transmitted electricity from other source, often from far distance.
3. Errors in coordination during interconnection national energy system.
4. Bad technical status of the network
3.3.6 Consequences analysis of the undesired event:
� Health consequences:
There is high probability of contamination because of zero or negative pressure in some areas of the network in
interruption water supply hours.
� Economic consequences:
During supply hours, the velocity of water in the pipes is more than designed values so that causes equipments
failure.
� Social-economic consequences:
Inconvenience for customers to supply water many hours a day, Costumers should pay for pumping because of low
pressure in the network and storage tanks
4 CASE STUDIES:
Water supply system of Našiměřice in Czech Republic was chosen, and two independent cases carried out, the first
is the real existing case, and the second is a theoretical case supposes hazards that cause intermittent water supply.
4.1 Našiměřice water supply system description:
Našiměřice village is located on south Moravia region in Czech Republic, with altitude ranges between 210 to
230m.
Water distribution system supplies app. 809 inhabitants; water is being supplied for domestic and other purposes by
Vodárenská Akciová společnost a.s. water supply Company, division of Znojmo.
Water source is underground water, it is a well HV3, which was put into operation in 1962; it yields 1667
m3/month, water is pumped through DN100 cast iron material pipeline with a length of 973m to a globe shape tank
with a capacity of 200m3; the min. level of the tank is 249.23m.a.s.l
The distribution network was been constructed in 1973-1976; it consists of PVC pipelines with 628m length, steel
pipelines with 523m length, and cast iron pipelines with 1747m length.
About the quality, the supplied water is healthy and treated only with chlorine; there was just a problem in terms of
uranium, up to 31.12.2009 uranium percentage was approximately 30 μg/l but since 1.1.2010 it has been limited up to
15 μg/l.
By going back to the table .1. , we can notice that the system is considered as a simple WSS
4.2 The real case study:
As mentioned before, the subsystems should be analyzed separately.
4.2.1 Underground water source:
The possible failures and hazards are:
� 3.01 Electrical power cut

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3. Water Management and Water structures
� 3.03 Equipment (pumps) failure
� 3.06 Inappropriate characteristics of the delivered water, failure in dosage of sodium hypochlorite, which is the
dominant hazard.
The estimated UE are:
� NS101 Deterioration of raw water quality - K5,
� NS103 Contamination of raw water with chemical pollutants - K5,
� NS104 Contamination of raw water with microbiology pollutants - K2, and
� NS105 Insufficient capacity of the sources - K5
4.2.2 Distribution system:
The possible failures and hazards are:
� 2.07 Control mechanisms
� 2.27 Change in legislation
� 3.01 Failure in the electrical power supply
� 3.03 Failure in the equipments
� 3.05 Inappropriate properties of construction materials.
� 3.06 Inappropriate characteristics of the delivered water.
� 3.09 Interconnection systems.
� 3.10 Reverse flow from connection to the system.
� 3.15 Insufficient hydraulic capacity
� 3.19 Aging materials and changing their properties.
� 3.21 Bad technical status of objects, pipelines, and valves.
The estimated UE are:
� NS302 Degradation quality of drinking water in the - tanks K3
� NS202 Failure in chemical dosages - K1.
� NS340 Corrosion of metal pipe - K2.
4.2.3 The results:
From the risk matrix, we can notice that, three UEs with extreme high risk K5, and one UE with low risk K2 affect
the source, while three UEs with average K3, low K2, and very low K1 risks affect the distribution part.
Fig.3. Risk matrix of the real case study
4.2.4 Suggestions :
Regarding to the current legislation, a high unacceptable risk exists from the selected undesired event NS101 in the
source, the solution is that water will need to either adjust or switch to another source.
The resulting risk from UE NS202 is acceptable because the microbial defectiveness doesn’t increase because of
the failure of dosage of disinfectant in through underground sources.
The resulting risks from NS302 and DNS340 are acceptable, because just the sensory properties of drinking water
are worsening because of it.
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3. Water Management and Water structures
4.3 The theoretical case study:
This case study supposes hazards that force water utilities to shift supply patterns from continuous to intermittent
water supply.
4.3.1 Underground water source:
The possible failures and hazards are:
� 1.06 Droughts
� 1.09 Global climate changes
� 2.02 Operation method
� 2.09 Inappropriate management with the water source
� 3.01 Failure in the electrical power supply
� 3.03 Failure in the equipments
� 3.15 Insufficient hydraulic capacity
� 3.21 Bad technical status of objects, pipelines, and valves
The estimated UE are:
� NS101 Deterioration of raw water quality
� NS105 Insufficient capacity of the sources
4.3.2 Distribution network
The possible failures and hazards are:
� 2.02 Operation method
� 2.09 Inappropriate the management with the source of water
� 2.11 Costumers
� 3.01 Failure in the electrical power supply
� 3.03 Failure in the equipments
� 3.12 high operational pressure.
� 3.15 Insufficient hydraulic capacity
� 3.21 Bad technical status of objects, pipelines, and valves.
Some of estimated UE are:
� NS_328 Failure of water mains with temporary interruption in the water supply- K1
� NS_332 Deterioration in taste, smell, and temperature of the water-K4
� NS_336 Insufficient hydraulic capacity – K5
� NS_344 Failure in shut-off valves, and gate valves
� NS_345 Intermittent water supply
4.3.3 The results:
From the figure.3, we can notice that, two UEs affect the source with extreme high risk K5. While ten UEs affect
the distribution system from the storage tank to the tap, one is extreme high K5, one is high K4, two are average K3,
two are low K2, and four are very low K1 risks.

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3. Water Management and Water structures
Figure.4. risk matrix of the theoretical case study
5 CONCLUSIONS:
The developed methodology is suitable for existing water supply systems, supported with simple software tool,
adaptable, and it presents the results in comprehensive matrix that can easily deal with.
The intermittent water supply pattern is not acceptable in Czech Republic even if it is acceptable in some
developing countries to cope insufficient water sources, increasing in demand in parallel with decreasing in sources,
failure in the electrical power supply or in the equipments of the network.
Intermittent water supply is considered as extraordinary situation, so the research team of WaterRisk project
decided to insert it as a technical and technological undesired event in the catalogue of UEs in the software application.
By comparing the real case study with the intermittent supposed case study, we can notice that the undesired
events, which exist in the intermittent supply, are more than that exist in the continuous one.
The solutions are always depending on the economic situations of the countries, if the country doesn’t have enough
budget to treat or withdraw water from other sources, so it’s necessary to look for technical solutions to manage and
optimize the existing water source and networks, and control water demand by set higher tariff and billing, manage
water loss.
References:
[1] TUHOVCAK, Ladislav, RUCKA, Jan. Hazard identification and risk analysis of water supply systems. IWA
leasing edge conference. 10-2007, Czech Republic.
[2] TUHOVCAK, Ladislav;RUCKA, Jan. Analýza rizik veřejných vodovodů, Risk analysis in public water supply
system. first.Brno, Czech Republic:VUT,2010. 254s. ISBN 978-80-7204-676-8
[3] TUHOVCAK, L ; RUCKA, J ;KUCERA, T ;KOZISEK, V. Methods and techniques for risk assessment of
water supply systems. IWA World Water Congress, 9.2008, s. 153. Vienna.
[4] CABRERA-BEJAR, J. A; TZATCHOV, V. G. Inexpensive modelling of intermittent service water
distribution networks. ASCE. 2009, Mexico.
[5] INGEDULD, Petr; PRADHAN, Ajay . Modelling intermittent water supply systems with EPANET. [8]
annual WD symposium. 2006.
[6] www.waterrisk.cz [online]. Brno, Czech Republic.
[7] VALESOVA, Martina. Risk analysis of water supply systems, Brno, Czech Republic 2010. Diplomova
prace.VUT.
Reviewer
Ing. Jan Ručka, PhD, Brno University of Technology, Civil engineering Faculty, institute of Municipal water
Management, odborný asistent, Brno 60200, Žižkova 17, +420 54114-7734, rucka.j@fce.vutbr.cz.
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