Upload
truongduong
View
232
Download
3
Embed Size (px)
Citation preview
Identification and description of hazards for water supply systems
A catalogue of today’s hazards and possible future hazards Preliminary version
Techneau, 07. FEBRUARY 2007
© 2006 TECHNEAU TECHNEAU is an Integrated Project Funded by the European Commission under the Sixth Framework Programme, Sustainable Development, Global Change and Ecosystems Thematic Priority Area (contractnumber 018320). All rights reserved. No part of this book may be reproduced, stored in a database or retrieval system, or published, in any form or in any way, electronically, mechanically, by print, photoprint, microfilm or any other means without prior written permission from the publisher
Techneau, 07. FEBRUARY 2007
Identification and description of hazards for water supply systems
A catalogue of today’s hazards and possible future hazards Preliminary version
This report is: PU = Public
Colofon
Title Identification and description of hazards for water supply systems – A catalogue of today’s hazards and possible future hazards – Preliminary version Authors Ralph Beuken – Kiwa Water Research (Editor) Sebastian Sturm and Joachim Kiefer - TZW Mia Bondelind, Johan Åström and Andreas
Lindhe – Chalmers University of Technology Ingo Machenbach, Esa Melin, Thor Thorsen and
Bjørnar Eikebrokk - SINTEF Claudia Niewersch, Daniela Kirchner – RWTH
Aachen University Frantisek Kozisek and Daniel Weyessa Gari -
SZU. Chris Swartz - WRC SA / SWUE
Quality Assurance Thomas Petterson – Chalmers University of Technology Deliverable number D4.1.1 D4.1.2
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 1 - February, 2007
Contents
Contents 1
1 Introduction 3 1.1 Background 3 1.2 Today’s hazards 3 1.3 Future hazards 4 1.4 Objectives 4
2 Structure of Hazard Database 5 2.1 Introduction 5 2.2 Structure of the Hazard Database 6 2.3 Input from TECHNEAU partners 8
3 Proposed improvements of the Hazard Database 11
4 References 13
Appendix: Hazard Database 15 A 1. Surface water catchment 16 A 2. Groundwater catchment 20 A 3. Surface water intake and transport 24 A 4. Surface water infiltration 26 A 5. Groundwater and infiltration water abstraction and transport 29 A 6. Treatment 31 A 7. Reservoirs and pumps 55 A 8. Drinking water transport and distribution 58 A 9. Internal piping 61 A 10. Consumer 63 A 11. Organization 65 A 12. Future hazards (including the whole drinking water system) 66
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 2 - February, 2007
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 3 - February, 2007
1 Introduction
1.1 Background The main objective of WA4 (Risk assessment and risk management) is to integrate risk assessments of the separate parts of a water supply system into a comprehensive decision support framework for cost-efficient risk management in safe and sustainable drinking water supply. One of the first aspects that need to be addressed in risk management is the identification and description of potential hazards. The position of hazard identification within the risk management process is presented in Figure 1. For a description of the risk management framework adopted in this project, see [1].
Figure 1: The risk management process and the position of hazard identification [2].
1.2 Today’s hazards Traditionally, hazard identifications are performed for separate parts of the water supply system. Within the TECHNEAU-project the water supply system is regarded as a whole and the identification of hazards is done from source to consumer’s tap. The consequences of hazards are related to all the stages of the water supply and the chain of cause and consequences is evaluated through the process. Applying this holistic view helps water companies in preventing sub-optimization of risk management when focussing on specific aspects of water supply. The hazards identified in this report are internal as well as external. Internal hazards are mostly related to function failures or the absence of
Risk analysis
• Scope definition • Hazard identification • Risk estimation
Risk evaluation
• Risk tolerability decisions • Analysis of options
Risk reduction/control
• Decision making • Implementation • Monitoring
Risk assessment
Risk management
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 4 - February, 2007
infrastructure. External hazards are for instance source water contamination, degradation of mains due to aggressive soils or terrorist actions. The hazards identified in this report are general hazards of technical, geographical or human origin, having direct effect on the infrastructure for water supply. Other types of risks, for example of political or economical origin are not assessed specifically in this report. The database focuses on the primary process of water supply. To limit its scope supporting activities like buildings, constructions, electrical installations are not mentioned.
1.3 Future hazards To manage risks efficiently it is important to identify today’s hazards as well as future hazards. Based on a literature review, interviews, evaluation work carried out at Chalmers University of Technology, and contributions from WA1 partners in the SEPTEDOR (Socio-cultural, Economical, Political, Technical, Ecological, Demographic, Organizatorial and Risk) analysis, major future trends have been identified. The implications of these trends for water supply have been studies and the following categories of hazards have been identified:
• Sabotage and terrorist attacks • Conflicts • New chemicals and changed chemical pathways • Emerging pathogens • Public concern • Climate changes • Aging distribution systems
All identified future hazards are presented in Appendix 12. For a more detailed description of the future hazards see [3].
1.4 Objectives The objective of this database is to help end-users working in water supply systems with the identification of relevant hazards by providing a catalogue with potential hazards of technical, geographical or human origin for the whole part of the system. The database has a generic set-up. It does not cover all possible specific operational hazards, but should be regarded as a checklist to assess possible risks of the supply system. The purpose of this document is a thorough review of the main existing hazards that may cause risks in the drinking water supply system. Existing national checklists and databases have been taken into consideration during the preparation of the hazard database [4-11]. The report in this preliminary version will be used and tested mainly by TECHNEAU partners and committed end-users during various case-studies. An updated version of this report will then be presented in the end of 2007. Hazards derived from ‘possible futures’, described in WA1, are also included into this report. The description of the existing and future hazards will be used in the subsequent work packages in WA4.
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 5 - February, 2007
2 Structure of Hazard Database
2.1 Introduction A definition of the system to be studied has to be given in order to identify hazards. Within this project the water supply system is defined as all physical and organisational structures for the supply of drinking water, stretching out from the catchment area to the customer (from source to tap). Hazards related to the handling of water by consumers at home are covered as well, as these types of hazards can be of importance for the quality of the consumed drinking water, especially for consumers that do not have in-house service connections. One crucial aspect in setting-up a hazard identification database is the required level of detail. The database has to be generic for ease of use and at the same time complete for providing sufficient information. The database presented in this study aims to cover both aspects. The water supply system is subdivided into 12 sub-systems, of which 10 are physical sub-systems representing the installations, one is a non-physical sub-system representing organizational aspects and one is a sub-system representing future hazards. A flow-diagram presenting these sub-systems is given in Figure 2. The breakdown is related to the ‘Generic system flow diagram’ as presented in the Water Safety Plans, which is described in the third edition of the Drinking Water Quality Guidelines of the WHO [4].
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 6 - February, 2007
12. Future hazards12. Future hazards
Figure 2 Water supply system subdivided into 12 sub-systems. (SW = surface water, GW = ground water, IW = Infiltration water)
2.2 Structure of the Hazard Database The hazard database is presenting the identified hazards in a table at the sub-system level in Appendix 1-12. The tables are divided into components and elements. At component level the most important elements are given and per element the most relevant hazards are given in combination with a description of the cause of the hazard, the hazard type and the consequences. The format of the hazard database is derived from the Water Safety Plans [4]. The different components are represented in Table 1.
Sub-system Components 1. Surface water catchment 1.1. Catchment area
1.2. Monitoring system 2. Groundwater catchment 2.1. Catchment area
2.2. Monitoring system 3. Surface water intake and transport
3.1. Surface water intake 3.2. Surface water transport 3.3. Monitoring system
4. Surface water infiltration 4.1. Abstraction boreholes and surroundings 4.2. Catchment area 4.3. Monitoring system
Table 1: Subdivision of sub-systems into components.
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 7 - February, 2007
5. Groundwater and infiltration water abstraction and transport
5.1. Water abstraction facility 5.2. Surface water transport 5.3. Monitoring system
6. Treatment 6.1. Treatment, generic hazards 6.2. Chemicals used for treatment and
disinfection 6.3. Solids removal / screens 6.4. Coagulation / flocculation 6.5. Rapid sand filtration 6.6. Disinfection 6.7. Membrane filtration 6.8. Slow sand filtration
7. Reservoirs and pumps 7.1. Clear water reservoir 7.2. Pumping station 7.3. Valves
8. Drinkingwater transport and distribution
8.1. Network
9. Internal piping 9.1. Drinking water installation 10. Consumer 10.1. Water collection
10.2. Water storage and transportation 11. Organization 11.1. Organization 12. Future hazards (including the whole drinking water system)
12.1. Sabotage and terrorist attacks 12.2. Conflicts 12.3. New chemicals and changed chemical
pathways 12.4. Emerging pathogens 12.5. Public concern 12.6. Climate changes 12.7. Aging distribution systems
In the Water Safety Plans the following definitions are used [4]:
• A hazard is any biological, chemical, physical or radiological agent that has the potential to cause harm.
• A hazardous event is an incident or situation that can lead to the presence of a hazard (what can happen and how).
Within TECHNEAU a more broad definition of a hazard is given, as the project focuses on both water quality and water quantity. The hazard database makes use of the definitions given in Table 2.
Element: Lowest level of the system at which hazards are described.
Cluster: Group of elements (only used in sub-system Treatment, in Appendix 6, as this is more complex).
Hazard: A source of potential harm or a situation with a potential of harm (e.g. a biological, chemical, physical or radiological agent or undesired event that has the potential to have a negative
Table 2: Definitions applied in the hazard database.
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 8 - February, 2007
effect on the supply of safe and sufficient water).
Reference: Reference number of the hazard. Hazardous event: An event which can cause harm (e.g. an
incident or situation that can lead to the presence of a hazard, what can happen and how).
Type of hazardous event: Indication of the origin of the hazardous event. D: design-related O: operation-related E: external-related OS: consequence of a hazard in other
sub-system Ref. OS: reference of other sub-system
Type of hazard: Indication of the type of hazard. Biolog.: biological Chemic.: chemical Rad./phys.: radiological or physical
(including turbidity) Unavailib.: insufficient availability of
water supplied to customers
Safety: safety to personnel External damage: external damage to third
parties, including liability Consequence description: Description of potential consequences of the
hazard to other sub-systems at firstly and the consumer secondly.
Consequence to sub-system:
Reference of the sub-system affected by the hazard.
2.3 Input from TECHNEAU partners The identification of the hazards has been carried out by reviewing literature, interviewing experts from collaborating research institutes and interviewing operators. The sub-systems covered by the different partners within this work package, see Table 3.
Sub-system TECHNEAU partner
1. Surface water catchment Chalmers University of Technology
2. Groundwater catchment TZW, SZU and Chalmers University of Technology
3. Surface water intake and transport Chalmers University of Technology
4. Surface water infiltration TZW and SZU
Table 3: Contribution of the TECHNEAU partners
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 9 - February, 2007
5. Groundwater and infiltration water abstraction and transport
TZW and SZU
6. Treatment SINTEF, RWTH and Chalmers University of Technology
7. Reservoirs and pumps Kiwa Water Research
8. Transport and distribution Kiwa Water Research
9. Internal piping Kiwa Water Research
10. Consumer WRC SA /SWUE
11. Organization SINTEF
12. Future hazards Chalmers University of Technology
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 10 - February, 2007
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 11 - February, 2007
3 Proposed improvements of the Hazard Database
The TECHNEAU Hazard Database as described in this document will be tested in practice by the WP-partners. Based on this, improvements will be made to the database. Apart from these experiences, the following aspects have already been identified for improvement: 1. The sub-system Treatment needs more attention:
at some parts information is missing, at some parts the database seems to be very detailed, improvements of the structure and skipping of redundancies by a
further exchange of knowledge between the partners. 2. More effort has to be given to the use of standardized descriptions. 3. Chains of cause and effect through the system have to be described in a
better way. A proposal have been made by RWTH for restructuring the hazard database by discriminating 4 type of hazards (H), caused by 4 types of events (E) that can cause harm to consumers: H1: Hazards inherent to raw water sources in combination with absence of
appropriate treatment. H2: Hazards caused by external events (E1) resulting in a pollution of raw
water sources in combination with insufficient or malfunctioning treatment (E2).
H3: Hazards caused by events resulting in failures of parts of the water supply system (E3).
H4: Hazards caused by events resulting in malfunctioning monitoring of the water supply system (E4).
The abovementioned hazards and events are presented in Figure 3.
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 12 - February, 2007
Figure 3: Restructuring of hazards as proposed by RWTH (H: Hazard, E: Event)
Raw water source Barrier(water supply system) Consumers
H1
H2
H3
H4
E1 E4E3
E2
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 13 - February, 2007
4 References
[1] Rosén, L., P. Hokstad, A. Lindhe, S. Sklet, and J. Røstum (2007) Generic Framework and Methods for Integrated Risk Management in Water Safety Plans, TECHNEAU, In progress.
[2] IEC (1996) IEC60300-3-9, Risk Management - Part 3: guide to risk analysis of technological systems, International Electrotechnical Commission.
[3] Rosèn, L., and A. Lindhe (2007) Trend report – Report on trends regarding future risks, TECHNEAU.
[4] Davison A, G. Howard, M. Stevens, P. Callan, L. Fewtrell, D. Deere, and J. Bartram (2005) Water Safety Plans, Managing drinking-water quality from catchment to consumer. World Health Organization, WHO/SDE/WSH/05.06.
[3] Technische Regeln der Deutschen Vereinigung des Gas- und Wasserfaches e.V.: W 213-3, W 213-1, W 213-4, 213-5, W 217, W 218, W 219, W 220, W 223-1, W 225, W 290, W 294, W 1000.
[4] Glucina, K., A. Alvarez, and J.M. Laîné (2000) Assessment of an integrated membrane system for surface water treatment, Desalination 132, 73-82.
[5] Lipp, P. and G. Baldauf (2002) Application of out-in MF/UF-systems for drinking water treatment with air supported backwash – three case studies, Desalination 147, 63-68.
[6] Lozier, J., M. Kitis, C. Colvin, J.H. Kim, B. Mi, and B. Marinas (2004) Microbial removal and integrity monitoring of high-pressure membranes, Awwa Research Foundation.
[7] Vrouwenvelder, J.S., J.W.N.M. Kappelhof, S.G.J. Heijmann, J.C. Schippers, and D. van der Kooji (2003) Tools for fouling diagnosis of NF and RO membranes and assessment of the fouling potential of feed water, Desalination 157, 361-365.
[8] DVGW (2006) Richtlinien für Trinkwasserschutzgebiete; I. Teil: Schutzgebiete für Grundwasser. Technische Regel, Arbeitsblatt W 101, June 2006.
[9] Sturm, S. (2005) Schutz von Wassergewinnungsgebieten - Das neue DVGW-Arbeitsblatt W 101. Veröffentlichungen aus dem Technologiezentrum Wasser, 28 (ISSN: 1434-5765), 75–92, Karlsruhe.
[10] Nadebaum, P., M. Chapman, R. Morden, and S. Rizak (2004) A Guide To Hazard Identification & Risk Assessment For Drinking Water Supplies, Cooperative Research Centre for Water Quality and Treatment, Research Report Number 11.
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 14 - February, 2007
[11] Public Health Risk Management Plan Guides, Ministry of Health, New Zealand, available on the Ministry of Health’s Web site: www.moh.govt.nz.
Identification and description of hazards for water supply systems Kiwa WR © TECHNEAU - 15 - February, 2007
Appendix: Hazard Database
In the following appendices the hazard database for the sub-systems are presented.
A 1. Surface water catchment 16 A 2. Groundwater catchment 20 A 3. Surface water intake and transport 24 A 4. Surface water infiltration 26 A 5. Groundwater and infiltration water abstraction and transport 29 A 6. Treatment 31 A 7. Reservoirs and pumps 55 A 8. Drinking water transport and distribution 58 A 9. Internal piping 61 A 10. Consumer 63 A 11. Organization 65 A 12. Future hazards (including the whole drinking water system) 66
1. S
urfa
ce w
ater
cat
chm
ent
Elab
orat
ed b
y: C
halm
ers
Uni
vers
ity o
f Tec
hnol
ogy
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
1.1
Cat
chm
ent a
rea
1.1.
1In
dust
rial
dis
char
ges
XX
XC
onta
min
ated
raw
wat
er
(non
-pat
hoge
nic
orga
nism
s,
(non
) tox
ic c
hem
ical
s)
3 /
4
1.1.
2Er
osio
n of
sed
imen
ts b
y dr
edgi
ng o
r shi
ppin
gX
XX
Con
tam
inat
ed ra
w w
ater
(s
edim
ent,
toxi
c ch
emic
als,
pa
thog
ens)
3 /
4
1.1.
3Em
issi
ons
duri
ng
acci
dent
s (fi
re o
r ex
plos
ions
) e.g
. ind
ustr
ial
acci
dent
s or
fore
st fi
re
XX
Con
tam
inat
ed ra
w w
ater
(to
xic
chem
ical
s)3
/ 4
1.1.
4Tr
affic
acc
iden
ts w
ith
ship
s, tr
ains
, veh
icle
s an
d pl
anes
XX
XX
XX
Con
tam
inat
ed ra
w w
ater
((t
oxic
) che
mic
als)
3 /
4
1.1.
5Em
issi
ons
and
leac
hage
, oi
l spi
lls b
y sh
ippi
ng o
r tr
affic
XX
XC
onta
min
ated
raw
wat
er
(toxi
c ch
emic
als,
pat
hoge
ns)
3 /
4
1.1.
6H
arbo
ur a
ctiv
ities
, em
issi
ons,
acc
iden
tsX
XX
XC
onta
min
ated
raw
wat
er
(toxi
c ch
emic
als,
pat
hoge
ns)
3 /
4
1.1.
7To
xic
chem
ical
s fr
om a
ir
depo
sits
XX
XX
Con
tam
inat
ed ra
w w
ater
(to
xic
chem
ical
s)3
/ 4
1.1.
8In
tens
ive
fishe
ry, f
ish
farm
ing,
mas
sive
fish
de
ath
XX
XC
onta
min
ated
raw
wat
er
(toxi
c ch
emic
als)
3 /
4
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Cat
chm
ent
zone
Con
tam
inat
ion
of
catc
hmen
t zon
e
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 1. Surface water catchment
- 16 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
1.1.
9N
ucle
ar p
ower
acc
iden
tX
XX
XC
onta
min
ated
raw
wat
er
(rad
ionu
clei
ds)
3 /
4
1.1.
10D
elib
erat
e co
ntam
inat
ion
by s
abot
age
or te
rror
ist
actio
n
XX
XX
XX
Con
tam
inat
ed ra
w w
ater
(p
atho
gens
, tox
ic c
hem
ical
s or
radi
onuc
leid
s);
insu
ffici
ent r
aw w
ater
3 /
4
1.1.
11D
isru
pted
inflo
w s
uch
as
failu
re o
f dam
s, d
rou g
ht o
r ex
trem
e ru
noff
XX
XC
onta
min
ated
raw
wat
er
(toxi
c ch
emic
als)
; in
suffi
cien
t raw
wat
er
3 /
4
1.1.
12Ea
rthq
uake
, lan
dslid
esX
XX
XC
onta
min
ated
raw
wat
er
(pat
hoge
ns o
r tox
ic
chem
ical
s); i
nsuf
ficie
nt ra
w
wat
er
3 /
4
1.1.
13La
trin
es in
boa
tsX
XX
Con
tam
inat
ed ra
w w
ater
(p
atho
gens
or n
utri
ent l
oads
in
wat
er)
3 /
4
1.1.
14Er
osio
n in
to c
atch
men
t w
ith re
leas
e of
soi
l, sa
nd
or c
onta
min
ants
XX
XC
onta
min
ated
raw
wat
er
(toxi
c ch
emic
als)
3 /
4
1.1.
15O
verf
low
ing
CSO
'sX
XX
Con
tam
inat
ed ra
w w
ater
(p
atho
gens
or t
oxic
ch
emic
als)
3 /
4
Con
tam
inat
ion
by
leac
hage
of s
ea
wat
er in
to th
e fr
esh
wat
er
1.1.
16H
igh
sea
leve
l and
or
stor
ms
XX
XC
onta
min
ated
raw
wat
er
(sal
inity
in e
leva
ted
leve
ls)
3 /
4
Shor
tage
of w
ater
1.1.
17D
roug
ht, b
lock
age
of
wat
er u
pstr
eam
or
abst
ract
ion
by th
ird
part
y
XX
Insu
ffici
ent r
aw w
ater
3 /
4
A 1. Surface water catchment
- 17 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
1.1.
18D
iffus
e w
aste
wat
er e
.g.
sing
le h
ouse
hold
sew
age
tank
, lea
king
sew
ers,
ov
erflo
win
g C
SO's
XX
XC
onta
min
ated
raw
wat
er
(pat
hoge
ns, n
on-to
xic
chem
ical
s, n
utri
ent l
oad)
3 /
4
1.1.
19M
anur
e sp
read
or c
attle
in
prot
ectio
n zo
neX
XX
Con
tam
inat
ed ra
w w
ater
(p
atho
gens
, nut
rien
t loa
d)3
/ 4
1.1.
20A
gric
ultu
re ru
noff
cont
aini
ng fe
rtili
zers
, sl
udge
, her
bici
des
etc
XX
XC
onta
min
ated
raw
wat
er
(pat
hoge
ns, n
on-to
xic
chem
ical
s, n
utri
ent l
oad)
3 /
4
1.1.
21C
ontin
uous
leak
age
from
la
ndfil
ls a
nd c
onta
min
ated
so
ils
XX
XC
onta
min
ated
raw
wat
er
(non
-toxi
c ch
emic
als)
3 /
4
1.1.
22Ef
fluen
t of W
WTP
, nor
mal
op
erat
ions
or f
ailu
reX
XX
Con
tam
inat
ed ra
w w
ater
(p
atho
gens
, non
-toxi
c ch
emic
als,
nut
rien
t loa
d)
3 /
4
1.1.
23Le
akin
g se
wer
s, la
trin
es
and
pres
ence
of C
SO's
XX
XC
onta
min
ated
raw
wat
er
(pat
hoge
ns, n
on-to
xic
chem
ical
s, n
utri
ent l
oad)
3 /
4
1.1.
24St
orm
wat
er e
fflue
nts
XX
XC
onta
min
ated
raw
wat
er
(pat
hoge
ns, n
on-to
xic
chem
ical
s, n
utri
ent l
oad)
3 /
4
1.1.
25Bi
rds
drop
ping
s or
an
imal
s al
low
ed to
cro
ss a
pr
otec
tion
zone
XX
XC
onta
min
ated
raw
wat
er
(pat
hoge
ns)
3 /
4Im
poun
d-m
ent
rese
rvoi
rC
onta
min
atio
n of
re
serv
oir
Surr
ound
-ings
of
cat
chm
ent
zone
Con
tam
inat
ion
of
surr
ound
ings
of
catc
hmen
t
Trib
utar
ies
to
catc
hmen
t zon
eC
onta
min
atio
n of
tr
ibut
arie
s up
stre
am
of c
atch
men
t
A 1. Surface water catchment
- 18 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
1.1.
26A
lgae
blo
oms
duri
ng
sum
mer
mon
th's
XX
XC
onta
min
ated
raw
wat
er
(alg
ae, t
oxic
che
mic
als,
nu
trie
nt lo
ad)
3 /
4
1.2
Mon
itori
ng s
yste
mM
onito
ring
sy
stem
Failu
re o
f m
onito
ring
sys
tem
1.2.
1A
ccid
ent,
defe
ct, p
ower
fa
ilure
, ope
ratio
nal f
ailu
re,
sabo
tage
, dam
aged
m
onito
ring
dev
ices
XX
XX
XX
XIn
suffi
cien
t and
/or
cont
amin
ated
raw
wat
er to
tr
eatm
ent
3 /
4
A 1. Surface water catchment
- 19 -
2. G
roun
dwat
er c
atch
men
t (in
clud
ing
prot
ectio
n zo
nes)
Elab
orat
ed b
y: T
ZW, S
ZU a
nd C
halm
ers
Uni
vers
ity o
f tec
hnol
ogy
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
2.1
Cat
chm
ent a
rea
2.1.
1C
onta
min
atio
n by
in
dust
rial
or t
radi
ng
esta
tes,
bui
ldin
g ac
tiviti
es,
oper
atio
n of
inst
alla
tions
, pi
pelin
e sy
stem
s w
ith
haza
rdou
s (to
xic,
ra
dioa
ctiv
e) s
ubst
ance
s,
traf
fic, a
ggre
ssiv
e pe
rson
s ne
ar th
e ca
tchm
ent a
rea
(incl
acc
iden
ts)
XX
XX
Con
tam
inat
ed ra
w w
ater
5
2.1.
2C
onta
min
atio
n by
was
te
wat
er e
.g. b
y W
WTP
, se
wer
s, la
trin
es
XX
XC
onta
min
ated
raw
wat
er5
2.1.
3Le
achi
ng o
ut o
f co
ntam
inat
ed /
toxi
c su
bsta
nces
by
built
co
nstr
uctio
ns e
.g. l
andf
ills
usin
g w
aste
or
cont
amin
ated
gro
und,
du
mps
ites,
traf
fic fa
cilit
ies,
inst
alla
tions
for h
andl
ing,
st
orag
e an
d de
posi
tion
of
was
te m
ater
ials
or
exca
vatio
n re
sidu
es
XX
XC
onta
min
ated
raw
wat
er5
Refe
renc
e
Cat
chm
ent a
rea
Dir
ect c
onta
min
atio
n of
gro
und
wat
er
laye
rs
Elem
ent
Haz
ard
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Haz
ardo
us e
vent
Type
of h
azar
dous
ev.
A 2. Groundwater catchment
- 20 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.
2.1.
4C
onta
min
atio
n by
traf
fic,
incl
acc
iden
ts (r
ailw
ay
trac
ks, a
irfie
lds,
road
s,
park
ing
area
s, p
etro
l fil
ling
stat
ions
)
XX
XC
onta
min
ated
raw
wat
er5
2.1.
5C
onta
min
atio
n by
co
nstr
uctio
n ac
tiviti
es w
ith
inte
rfer
ence
in s
ubso
il,
wat
erw
ay c
onst
ruct
ion,
in
stal
latio
ns fo
r han
dlin
g or
sto
rage
of h
azar
dous
su
bsta
nces
, fac
ilitie
s fo
r co
nstr
uctio
n w
orke
rs (i
ncl
acci
dent
s)
XX
XC
onta
min
ated
raw
wat
er,
unav
aila
bilit
y of
raw
wat
er5
2.1.
6C
onta
min
atio
n by
op
erat
ions
, inc
reas
ing
vuln
erab
ility
due
to
min
ing
activ
ities
, gra
vel
pits
, exc
avat
ions
un
cove
ring
the
GW
, co
nstr
uctio
n of
faci
litie
s fo
r geo
ther
mal
pow
er
purp
oses
and
/or
sm
all
wat
er s
uppl
y sy
stem
s
XX
XX
Con
tam
inat
ed ra
w w
ater
5
A 2. Groundwater catchment
- 21 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.
2.1.
7C
onta
min
atio
n by
ag
ricu
ltura
l act
iviti
es s
uch
as th
e us
e of
fert
ilize
rs
and/
or p
estic
ides
XX
XC
onta
min
ated
raw
wat
er5
2.1.
8C
onta
min
atio
n by
faec
es
of c
attle
or m
anur
e on
land
XX
XC
onta
min
ated
raw
wat
er5
2.1.
9C
onta
min
atio
n by
ge
ophy
sica
l inc
iden
ts (e
.g.
extr
eme
hydr
aulic
eve
nts
such
as
torr
entia
l rai
n,
flood
s, e
rosi
on, l
ands
lides
, ka
rstic
land
sur
face
with
op
en d
olin
es)
XX
XX
Con
tam
inat
ed ra
w w
ater
5
2.1.
10A
ccid
ents
or s
prea
din g
out
of
haz
ardo
us m
ater
ials
du
ring
recr
eatio
nal
activ
ities
(e.g
. mas
s ra
llies
, fis
h po
nds,
sho
otin
g ga
lleri
es, s
port
s fa
cilit
ies
incl
. mot
or s
port
s, h
orse
-ra
ce g
roun
ds, z
oo /
ani
mal
re
serv
es, c
amps
, ca
mps
ites,
mili
tary
fiel
d ex
erci
ses
and
trai
ning
ar
eas)
XX
XC
onta
min
ated
raw
wat
er5
A 2. Groundwater catchment
- 22 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.
2.1.
11C
onta
min
atio
n by
fore
stry
ac
tiviti
es, w
ild li
fe
activ
ities
, lan
dslid
es
XX
XC
onta
min
ated
raw
wat
er5
2.1.
12G
eoph
ysic
al in
cide
nts
(e.g
. la
ndsl
ides
)X
XX
XC
onta
min
ated
raw
wat
er5
2.1.
13Bu
ildin
g a
ctiv
ities
(e.g
. m
inin
g, c
onst
ruct
ion
of
wel
ls, c
anal
s, p
its, e
tc)
XX
XX
Con
tam
inat
ed ra
w w
ater
5
Infil
trat
ion
of G
W b
y al
ien
wat
er2.
1.14
Wet
land
s &
floo
d pl
ains
no
t hyd
raul
ical
ly
sepa
rate
d fr
om th
e aq
uife
r
XX
XX
Con
tam
inat
ed ra
w w
ater
5
Shor
tage
of g
roun
d w
ater
reso
urce
s2.
1.15
Gro
und
wat
er a
quife
r is
not s
uffic
ient
ly fe
d or
w
ater
is a
bstr
acte
d by
ot
hers
XX
Una
vaila
bilit
y of
raw
wat
er5
2.2
Mon
itori
ng s
yste
mM
onito
ring
sy
stem
Failu
re o
f m
onito
ring
sys
tem
2.2.
1A
ccid
ent,
defe
ct, p
ower
fa
ilure
, ope
ratio
nal f
ailu
re,
sabo
tage
, dam
aged
gr
ound
wat
er o
bser
vatio
n w
ells
XX
XX
XX
Con
tam
inat
ed ra
w w
ater
, un
avai
labi
lity
of ra
w w
ater
5
Redu
ctio
n of
pr
otec
tive
cove
r, in
crea
sing
vu
lner
abili
ty o
f gr
ound
wat
er la
yers
A 2. Groundwater catchment
- 23 -
3. S
urfa
ce w
ater
inta
ke a
nd tr
ansp
ort
Elab
orat
ed b
y: C
halm
ers
Uni
vers
ity o
f Tec
hnol
ogy
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
3.1
Surf
ace
wat
er in
take
3.1.
1Ph
ysic
al o
bsta
cles
for t
he
inta
ke o
f raw
wat
erX
XX
X1
XIn
suffi
cien
t raw
wat
er to
tr
eatm
ent
4 /
6
3.1.
2Fa
ilure
in th
e ra
w w
ater
tu
nnel
XX
XIn
suffi
cien
t raw
wat
er to
tr
eatm
ent
4 /
6
Pipe
bur
st3.
1.3
Bad
cond
ition
or e
xter
nal
caus
es (e
.g. l
ands
lides
, he
avy
traf
fic)
XX
XX
Insu
ffici
ent r
aw w
ater
to
trea
tmen
t4
/ 6
Inta
ke b
asin
Con
tam
inat
ion
and
/ or
una
vaila
bilit
y of
w
ater
3.1.
4W
ater
sho
rtag
e or
co
ntam
inat
ion
lead
ing
to
(par
tly) c
losi
ng o
f int
ake,
no
alte
rnat
ive
raw
wat
er
sour
ce
X1
XX
XX
Insu
ffici
ent a
nd/o
r co
ntam
inat
ed ra
w w
ater
to
trea
tmen
t
4 /
6
3.2
Surf
ace
wat
er tr
ansp
ort
Pum
psPo
wer
failu
re
3.2.
1Po
wer
inte
rrup
tion
and
no
back
up p
ower
sup
ply
XX
XX
Una
vaila
bilit
y of
raw
wat
er4
/ 6
Raw
wat
er
mai
nsPi
pe b
urst
3.2.
2Ba
d co
nditi
on o
f mai
ns o
r ex
tern
al c
ause
s (e
.g.
land
slid
es, h
eavy
traf
fic)
XX
XX
XIn
suffi
cien
t raw
wat
er to
tr
eatm
ent
4 /
6
Shor
tage
/
unav
aila
bilit
y of
w
ater
Inta
ke tu
nnel
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 3. Surface water intake and transport
- 24 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
3.3
Mon
itori
ng s
yste
mM
onito
ring
sy
stem
Failu
re o
f m
onito
ring
sys
tem
3.3.
1A
ccid
ent,
defe
ct, p
ower
fa
ilure
, ope
ratio
nal f
ailu
re,
sabo
tage
, dam
aged
m
onito
ring
dev
ices
XX
XX
XX
Insu
ffici
ent a
nd/o
r co
ntam
inat
ed ra
w w
ater
to
trea
tmen
t
4 /
6
A 3. Surface water intake and transport
- 25 -
4. S
urfa
ce w
ater
infi
ltrat
ion
Elab
orat
ed b
y: T
ZW a
nd S
ZU
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
4.1.
Abs
trac
tion
bore
hole
(s) a
nd s
urro
undi
ngs
Wat
er s
ourc
e ar
eaD
irec
t con
tam
inat
ion
of a
bstr
actio
n bo
reho
les)
and
su
rrou
ndin
g gr
ound
(b
ank)
by
man
mad
e ac
tiviti
es (l
andf
ills,
in
dust
rial
was
te
outle
ts e
tc.)
or
acci
dent
s (e
.g. t
raffi
c ac
cide
nts)
4.1.
1To
xic
chem
ical
s an
d pa
thog
ens
from
acc
iden
ts
with
trai
ns, v
ehic
les
and
plan
es, f
rom
land
fills
or
was
tew
ater
dis
char
ge
XX
XX
Toxi
c ch
emic
als
and
path
o gen
s in
filtr
ate
to w
ater
sy
stem
Wat
er s
ourc
e ar
eaC
onta
min
atio
n of
gr
ound
wat
er s
yste
m
by p
ollu
ted
surf
ace
wat
er in
filtr
atio
n
4.1.
2In
tens
ive
agri
cultu
ral
activ
ities
(far
min
g,
appl
icat
ion
of fe
rtili
zers
an
d pe
stic
ides
, woo
d pr
eser
vativ
es e
tc.)
XX
XD
eter
iora
tion
of w
ater
qu
ality
due
to in
trod
uctio
n of
hea
vy m
etal
s, b
adly
de
grad
able
org
anic
co
mpo
unds
, nitr
ogen
, ph
osph
orou
s, p
atho
gens
etc
(w
ater
qua
lity)
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 4. Surface water infiltration
- 26 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Wat
er s
ourc
e ar
eaD
irec
t con
tam
inat
ion
of w
ater
sou
rce
area
by
sab
otag
e ac
t, te
rror
ism
or
vand
alis
m
4.1.
3V
ario
us to
xic
chem
ical
s an
d pa
thog
ens
XX
Pollu
tion
of w
ater
sou
rce
Wat
er s
ourc
e ar
eaD
irec
t con
tam
inat
ion
of a
bstr
actio
n bo
reho
les)
and
su
rrou
ndin
gs (b
ank)
by
nat
ural
dis
aste
rs
(ear
thqu
ake,
flo
odin
g, la
ndsl
ide,
fir
e et
c...)
4.1.
4To
xic
chem
ical
s, s
alts
, pa
thog
ens
from
w
aste
wat
ers,
land
fills
, ru
noff,
acc
iden
ts.
Mec
hani
cal d
amag
e of
ab
stra
ctio
n si
tes.
XX
XTo
xic
chem
ical
s, p
atho
gens
in
wat
er
4.2.
Cat
chm
ent a
rea
Cat
chm
ent a
rea
Shor
tage
of
infil
trat
ed w
ater
to
the
soil/
aqui
fer o
f ab
stra
ctio
n ar
ea
4.2.
1.H
uman
act
ivity
by
build
ing
diffe
rent
st
ruct
ures
alo
ngsi
de th
e ri
ver b
ank,
poo
r lan
d us
e m
anag
emen
t, ir
riga
tion
in
agri
cultu
re, p
oor s
oil
cons
erva
tion
etc.
, pr
even
ting
pass
age
of
wat
er fr
om s
urfa
ce w
ater
, cl
oggi
ng o
f the
infil
trat
ion
pond
s/ri
verb
ank
XX
Wat
er s
hort
age
in th
e so
il an
d th
en p
oor d
isch
arge
(w
ater
qua
ntity
)
A 4. Surface water infiltration
- 27 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Cat
chm
ent a
rea
Con
tam
inat
ion
of
grou
nd w
ater
sy
stem
(inf
iltra
tion)
be
caus
e of
pol
lute
d so
urce
sur
face
wat
er
4.2.
2.se
e Se
ctio
n: 1
. Sur
face
w
ater
cat
chm
ent z
one,
i.e.
1.
1 up
to 1
.4.
XX
XIn
trod
uctio
n of
che
mic
als
(or g
anic
and
inor
gani
c), a
nd
path
ogen
to th
e w
ater
sy
stem
.
4.3
Mon
itori
ng s
yste
mM
onito
ring
sy
stem
Failu
re o
f m
onito
ring
sys
tem
4.3.
1A
ccid
ent,
defe
ct, p
ower
fa
ilure
, man
agem
ent
failu
re, h
uman
mis
take
, sa
bota
ge, d
amag
ed
grou
ndw
ater
obs
erva
tion
wel
ls
XX
XX
XX
Toxi
cs a
nd p
atho
gens
in
grou
ndw
ater
. C
onta
min
atio
n of
gr
ound
wat
er a
nd
envi
ronm
ent
A 4. Surface water infiltration
- 28 -
5. G
roun
dwat
er a
nd in
filtr
atio
n w
ater
abs
trac
tion
and
tran
spor
tEl
abor
ated
by:
TZW
and
SZU
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
5.1
Wat
er a
bstr
actio
n fa
cilit
yC
rack
s (e
.g. i
n ch
ambe
r wal
ls),
lead
ing
to in
gres
s of
sh
allo
w w
ater
5.1.
1Tr
ees,
root
s, c
rack
s in
co
ncre
teX
XX
XX
Con
tam
inat
ed ra
w w
ater
to
trea
tmen
t (pa
thog
ens
&
toxi
cs);
dam
ages
to
infr
astr
uctu
re
6
Infil
trat
ion
of ru
n-of
f w
ater
5.1.
2Ru
n-of
f wat
erX
XX
XX
Con
tam
inat
ed ra
w w
ater
to
trea
tmen
t (pa
thog
ens
&
toxi
cs)
6
Ope
ning
s in
sy
stem
Pollu
tion
/ co
ntam
inat
ion
thro
ugh
open
ings
( w
ell-h
ead
/ ve
ntila
tion
pipe
/
grit
cham
ber /
st
illin
g ba
sin
/ ov
erflo
w p
ipe
/ do
ors)
5.1.
3Po
llutio
n by
floo
ding
, sa
bota
ge, a
nim
als
XX
XX
XX
XC
onta
min
ated
raw
wat
er to
tr
eatm
ent (
path
ogen
s &
to
xics
)
6
Ass
et
prot
ectio
n (fe
nces
, cl
osur
e)
Secu
rity
failu
re,
caus
ing
cont
amin
atio
n
5.1.
4Im
prop
er lo
ckin
g of
the
syst
em a
nd s
abot
age
XX
XX
XX
XX
Con
tam
inat
ed ra
w w
ater
to
trea
tmen
t (pa
thog
ens
&
toxi
cs)
6
Bent
onite
la
yers
Soil
setti
ng a
nd
hydr
aulic
byp
ass
5.1.
5Im
prop
er b
ento
nite
laye
rs,
or m
issi
ngX
XX
Con
tam
inat
ed ra
w w
ater
to
trea
tmen
t (pa
thog
ens
&
toxi
cs)
6
Gen
eric
si
tuat
ion
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ardo
us e
v.Ty
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 5. Groundwater and infiltration water abstraction and transport
- 29 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ardo
us e
v.Ty
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Wel
l cha
mbe
rSo
il se
tting
, flo
odin
g, c
ham
ber
buo y
ancy
, co
rros
ive
soil
mat
eria
ls
5.1.
6Im
prop
er m
aint
enan
ce
conc
ept,
flood
ala
rm a
nd
sum
p pu
mp
lack
ing
XX
XX
XC
onta
min
ated
raw
wat
er to
tr
eatm
ent (
path
ogen
s &
to
xics
)
6
5.2
Gro
undw
ater
tran
spor
tPu
mps
Pow
er fa
ilure
5.
2.1
Pow
er in
terr
uptio
n an
d no
ba
ckup
pow
er s
uppl
y X
XX
XIn
suffi
cien
t raw
wat
er to
tr
eatm
ent
6
Raw
wat
er
mai
nsPi
pe b
urst
5.2.
2Ba
d co
nditi
on o
f mai
ns o
r ex
tern
al c
ause
s (e
.g.
land
slid
es, h
eavy
traf
fic)
XX
XX
XIn
suffi
cien
t raw
wat
er to
tr
eatm
ent
6
5.3
Mon
itori
ng s
yste
mM
onito
ring
sy
stem
Failu
re o
f m
onito
ring
sys
tem
5.3.
1A
ccid
ent,
pow
er fa
ilure
, op
erat
iona
l fai
lure
, sa
bota
ge, d
amag
ed
mon
itori
ng d
evic
es
XX
XX
XX
Con
tam
inat
ed a
nd/o
r in
suffi
cien
t raw
wat
er to
tr
eatm
ent
6
A 5. Groundwater and infiltration water abstraction and transport
- 30 -
6. T
reat
men
t (ex
clud
ing
soil
infi
ltrat
ion
and
recl
amat
ion)
Elab
orat
ed b
y: S
INTE
F, R
WTH
and
Cha
lmer
s U
nive
rsity
of T
echn
olog
y
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
6.1
Trea
tmen
t, ge
neri
c ha
zard
sD
esig
nIn
suffi
cien
t tr
eatm
ent d
ue to
in
adeq
uate
des
ign
of th
e tr
eatm
ent
proc
ess
in re
latio
n to
raw
wat
er q
ualit
y (a
t all
or d
ue to
pe
ak p
ollu
tion
even
ts)
6.1.
1E.
g. in
effe
ctiv
e re
mov
al o
f po
luta
nts
and
cont
rol o
f D
BP
XX
X01
XX
XX
XRe
duce
d w
ater
qua
lity
and/
or a
vaila
bilit
y7
Ope
ratio
nIn
suffi
cien
t tr
eatm
ent d
ue to
no
n-op
timal
op
erat
ion
or
mai
nten
ance
of
trea
tmen
t pro
cess
6.1.
2E.
g. n
ot a
dequ
ate
coag
ulan
ts a
re u
sed,
im
prop
er p
H v
alue
is
mai
ntai
ned,
no
prop
er
dose
of c
oagu
lant
is u
sed
etc,
XX
XX
XX
Redu
ced
wat
er q
ualit
y an
d/or
ava
ilabi
lity
7
Elec
tric
al
pow
erIn
suffi
cien
t tr
eatm
ent d
ue to
po
wer
inte
rrup
tions
6.1.
3N
o or
uns
tabl
e el
ectr
ical
po
wer
and
no
or fa
iling
ba
ck-u
p
XX
XX
XX
XX
Redu
ced
wat
er q
ualit
y an
d/or
ava
ilabi
lity
7
Use
of
mat
eria
lsC
onta
min
atio
n or
w
ear d
ue to
the
use
of m
ater
ials
not
su
itabl
e fo
r con
tact
w
ith d
rink
ing
wat
er 6.
1.4
E.g.
coa
tings
, ion
-ex
chan
ge re
sins
, iro
n no
t pr
otec
ted
agai
nst
corr
osio
n et
c.
XX
XLe
achi
ng s
ubst
ance
s an
d su
ppor
t of
mic
robi
al g
row
th
7
Flow
con
trol
Insu
ffici
ent
trea
tmen
t due
to
non-
optim
al fl
ow
6.1.
5Fl
ow m
eter
is n
ot
calib
rate
dX
XX
XX
Redu
ced
wat
er q
ualit
y an
d/or
ava
ilabi
lity
7
-
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 6. Treatment
- 31 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Gen
eral
Nat
ural
dis
aste
rs
resu
lting
in
dest
ruct
ion
of
trea
tmen
t mod
ules
6.1.
6E.
g. e
arth
quak
es, s
torm
sX
XX
XX
XRe
duce
d w
ater
qua
lity
and/
or a
vaila
bilit
y7
Raw
wat
erIn
suffi
cien
t qua
ntity
of
raw
wat
er6.
1.7
Haz
ards
in ra
w w
ater
ab
stra
ctio
n or
tran
spor
tX
02X
XX
XRe
duce
d w
ater
qua
lity
and/
or a
vaila
bilit
y7
Raw
wat
erIn
suffi
cien
t qua
lity
of ra
w w
ater
6.1.
8H
azar
ds in
raw
wat
er
abst
ract
ion
or tr
ansp
ort
X02
XX
XX
Redu
ced
wat
er q
ualit
y an
d/or
ava
ilabi
lity
7
6.2
Che
mic
als
used
for t
reat
men
t or d
isin
fect
ion
Qua
lity
of
chem
ical
sIn
suffi
cien
t tr
eatm
ent d
ue to
ba
d qu
ality
of
chem
ical
s
6.2.
1U
se o
f pol
lute
d an
d/or
ex
pire
d ch
emic
als
XX
XX
XX
Insu
ffici
ent t
reat
men
t, ch
emic
al p
ollu
tion
of
wat
er, b
lock
ing
of
filte
rs e
tc.
7
Insu
ffici
ent
trea
tmen
t due
to
impr
oper
dos
ing
6.2.
2(a
) fai
lure
of d
osin
g un
it in
cl. p
ower
sup
ply;
(b) n
o su
ffici
ent s
uppl
y av
aila
ble;
(c) p
erso
nal
(ope
ratio
nal)
failu
re; (
d)
inco
rrec
t mea
sure
men
t
XX
XX
XX
idem
7
Ove
rdos
ing
of
chem
ical
s (a
ccid
enta
ly)
6.2.
3Fa
ilure
of t
he d
osin
g un
it or
ope
ratio
nal f
ailu
reX
XX
XX
Xid
em7
6.3
Solid
s re
mov
al /
scre
ens
Scre
ens
Bloc
kage
s in
sc
reen
ing
slee
ves
6.3.
1In
corr
ect s
cree
n si
ze o
r in
adeq
uate
cle
anin
gX
XX
Redu
ced
wat
er q
ualit
y an
d/or
ava
ilabi
lity
7
Dos
ing
of
chem
ical
s
--
A 6. Treatment
- 32 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Scre
ens
Bloc
kage
s in
sc
reen
ing
slee
ves
6.3.
2Fl
oods
, alg
al b
loom
or
vand
alis
mX
XRe
duce
d w
ater
qua
lity
and/
or a
vaila
bilit
y, e
g br
eakt
hrou
gh o
f pa
rtic
les
7
A 6. Treatment
- 33 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
6.4
Coa
gula
tion/
floc
cula
tion
Coa
gula
tion
flocc
ulat
ion
Raki
ng
syst
emEx
cess
ive
build
-up
of s
olid
s in
crea
se
carr
yove
r and
effe
ct
filte
r per
form
ance
6.4.
1C
lari
fier r
ake
syst
ems
are
not r
egul
arly
mai
ntai
ned
XX
XX
Yes
Coa
gula
tion
flocc
ulat
ion
Hyd
raul
ic
flocc
ulat
ion
Insu
ffici
ent
trea
tmen
t due
to
impr
oper
des
ign
6.4.
2Re
tent
ion
time
too
shor
tX
XX
Yes
Coa
gula
tion
flocc
ulat
ion
Mec
hani
cal
flocc
ulat
ion
Insu
ffici
ent
trea
tmen
t due
to
mec
hani
cal f
ailu
re
of th
e st
irre
r
6.4.
3Im
prop
er d
esig
nX
XX
Coa
gula
tion
flocc
ulat
ion
Dos
ing
Hig
h co
agul
ant
resi
dual
or r
educ
ed
capa
city
6.4.
4To
o lo
w o
r too
hig
h co
agul
ant d
ose
XX
XX
Hig
h tu
rbid
ity a
nd
insu
ffici
ent (
NO
M)
rem
oval
Yes
Coa
gula
tion
flocc
ulat
ion
pH-c
ontr
olSu
b-op
timal
co
agul
atio
n pH
6.4.
5Im
prop
er p
H c
ontr
olX
XX
Coa
gula
tion
flocc
ulat
ion
Mix
ing
flocc
ulat
ion
Insu
ffici
ent
flocc
ulat
ion
6.4.
6Im
prop
er c
oagu
lant
m
ixin
g an
d/or
flo
ccul
atio
n
XX
XX
Yes
Floc
cula
tion
Mon
omer
s in
the
wat
er6.
4.7
Usi
ng p
olym
ers
as
flocc
ulan
ts c
onta
inin
g no
n-flo
ccul
atin
g-m
onom
ers
XX
XC
onta
min
ants
(m
onom
ers)
in th
e w
ater
afte
r se
dim
enta
tion
or
filtr
atio
n
Yes
A 6. Treatment
- 34 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Floc
cula
tion
Inap
prop
riat
e flo
ccul
ant o
r flo
ccul
atio
n ag
ent
6.4.
8A
ltere
d va
riat
ions
in
wat
er q
ualit
y or
in
appr
opri
ate
pret
estin
g of
floc
cula
nts
XX
XX
Con
tam
inan
ts (e
.g.
flocc
ulan
ts) i
n th
e w
ater
afte
r se
dim
enta
tion
or
filtr
atio
n
Yes
Floc
cula
tion
6.4.
9In
appr
opri
ate
pH a
nd/o
r te
mpe
ratu
reX
XX
XX
Yes
Floc
cula
tion
6.4.
10D
ispe
rsin
g tim
e of
the
dosi
ng s
olut
ion
of
flocc
ulat
ion
a gen
ts
XX
XX
XYe
s
Floc
cula
tion
6.4.
11D
istu
rbin
g in
gred
ient
s in
the
wat
er th
e ch
emic
als
are
disp
erse
d w
ith
XX
XX
XYe
s
Floc
cula
tion/
flo
ccul
atio
n ag
ents
6.4.
12Pr
ecip
itatio
n du
e to
st
agna
nt re
gion
s in
the
wat
er ta
nk fo
r flo
ccul
atio
n ag
ents
bui
ld-
up
XX
XX
Yes
Floc
cula
tion
6.4.
13In
suffi
cien
t tur
bule
nce
for
the
initi
atio
n of
ag
greg
atio
n
XX
XX
Yes
Floc
cula
tion
6.4.
14In
suffi
cien
t mix
ing
of
dosi
ng m
ixtu
re a
nd w
ater
XX
XX
Yes
Floc
cula
tion
6.4.
15In
fluen
ce o
f Ca,
Mg,
PO
4,
SO4,
pH
, aci
d ca
paci
ty,
diss
olve
d or
gani
c m
atte
r
XX
XX
Yes
Floc
cula
tion
6.4.
16Ea
rth
alka
li in
the
wat
er
whe
n us
ing
poly
acry
lam
id a
s flo
ccul
atio
n ag
ent
XX
XX
XYe
s
Inap
prop
riat
e co
nditi
ons
duri
ng
disp
ersi
on o
f flo
ccul
ants
or
flocc
ulat
ion
agen
ts
in a
wat
er ta
nk
Con
tam
inan
ts (e
.g.
flocc
ulan
ts) i
n th
e w
ater
afte
r se
dim
enta
tion
or
filtr
atio
n
Adv
erse
con
ditio
ns
afte
r add
ing
the
wat
er-fl
occu
lant
/ flo
ccul
ant a
gent
m
ixtu
re to
the
wat
er
Con
tam
inan
ts (e
.g.
flocc
ulan
ts) i
n th
e w
ater
afte
r se
dim
enta
tion
or
filtr
atio
n
A 6. Treatment
- 35 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Floc
cula
tion/
flo
ccul
atio
n ag
ents
6.4.
17To
o sh
ort t
ime
betw
een
dosa
ge o
f flo
ccul
ant a
nd
flocc
ulat
ion
agen
t
XX
XX
Yes
Floc
cula
tion
6.4.
18O
zone
in th
e w
ater
XX
XX
XYe
sFl
occu
latio
n/
alum
iniu
m a
s flo
ccul
atio
n ag
ents
6.4.
19Ex
iste
nce
of c
ompl
ex-
bind
ing
orga
nic
subs
tanc
es o
r aci
d ra
w
wat
er w
hen
usin
g al
umin
ium
as
flocc
ulat
ion
agen
t
XX
XX
XC
onta
min
ants
(e.g
. flo
ccul
ants
) in
the
wat
er a
fter
sedi
men
tatio
n or
fil
trat
ion,
incr
easi
ng
conc
entr
atio
ns o
f su
lpha
te, c
hlor
ide,
so
dium
, inc
reas
ing
pH
and
corr
osio
n ri
sk d
ue
to h
ighe
r con
cent
ratio
n of
Al-s
alts
Yes
Floc
cula
tion/
flo
ccul
atio
n ag
ents
6.4.
20Fa
ilure
of t
he d
osin
g pu
mp
XX
XX
Yes
Floc
cula
tion
6.4.
21Po
wer
failu
re in
an
auto
mat
ised
con
trol
led
syst
em
XX
XX
Yes
Floc
cula
tion
Failu
re o
f the
au
tom
atis
ed,
prog
ram
mab
le
cont
rol s
yste
m
6.4.
22po
wer
failu
re,
prog
ram
mab
le e
rror
sX
XX
XX
XX
XYe
s
Floc
cula
tion
Biol
ogic
al
cont
amin
atio
n du
ring
the
flocc
ulat
ion
6.4.
23M
icro
biol
ogic
al a
ctiv
ity
whe
n us
ing
flocc
ulat
ion
agen
t con
tam
inat
ed b
y ye
ast
XX
XC
onta
min
ants
in th
e w
ater
afte
r se
dim
enta
tion
or
filtr
atio
n
Yes
Inco
rrec
t dos
ing
of
the
flocc
ulan
ts o
r flo
ccul
ant a
gent
s
Con
tam
inan
ts (e
.g.
flocc
ulan
ts) i
n th
e w
ater
afte
r se
dim
enta
tion
or
filtr
atio
n
A 6. Treatment
- 36 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Floc
cula
tion/
flo
ccul
atio
n ag
ents
Mic
robi
olog
ical
ac
tivity
in th
e tr
eate
d w
ater
6.4.
24Br
eakt
hrou
gh fl
occu
latio
n ag
ent c
onta
min
ated
by
yeas
t
XX
XBi
olog
ical
co
ntam
inan
ts in
the
wat
er a
fter
sedi
men
tatio
n or
fil
trat
ion
Yes
Floc
cula
tion
mon
itori
ng
6.4.
25In
suffi
cien
t sam
plin
g fr
eque
ncy
at c
ontr
ol p
oint
XX
Floc
cula
tion
mon
itori
ng
6.4.
26In
appr
opri
ate
mon
itori
ng
prog
ram
X
Floc
cula
tion
mon
itori
ng
6.4.
27M
alfu
nctio
n of
mea
suri
ng
inst
rum
ents
due
to
cons
truc
tion,
ope
ratio
n sy
stem
or m
aint
enan
ce
XX
Settl
ing
tank
Inad
equa
te fl
oc
settl
ing
due
to w
ind
and
/or l
ow
tem
pera
ture
s
6.4.
28X
XX
XYe
s
Settl
ing
tank
Insu
ffici
ent
trea
tmen
t due
to
impr
oper
des
ign
6.4.
29E.
g. u
pflo
w v
eloc
ity to
o hi
gh. W
eir o
verf
low
rate
to
o hi
gh. I
nsuf
ficie
nt
slud
ge d
raw
-off.
Re
tent
ion
time
too
shor
t.
XX
X
Settl
ing
tank
Insu
ffici
ent
trea
tmen
t due
to
inad
equa
te
desl
udgi
ng
prog
ram
me
6.4.
30Fl
oc c
arry
-ove
r tak
es
plac
eX
XX
Dis
solv
ed a
ir
flota
tion
Insu
ffici
ent
trea
tmen
t due
to
poor
bub
ble
form
atio
n
6.4.
31Pr
essu
re v
esse
l mat
eria
l. Pa
ckin
g m
ater
ial t
o en
sure
air
sat
urat
ion
XX
X
Del
ayed
or n
o de
tect
ion
of
cont
amin
ants
in th
e w
ater
afte
r the
se
dim
enta
tion
or
filtr
atio
n
Failu
re o
f the
m
onito
ring
of:
phys
ical
(e.g
. tu
rbid
ity, f
low
, pH
, A
l-loa
d),
biol
ogic
al
para
met
ers
(e.g
. E.
coli)
, pre
ssur
e,
chem
ical
pa
ram
eter
s
A 6. Treatment
- 37 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Dis
solv
ed a
ir
flota
tion
Insu
ffici
ent
trea
tmen
t due
to
impr
oper
des
ign
6.4.
32Re
actio
n zo
ne a
nd/o
r cl
arifi
catio
n zo
ne n
ot
size
d co
rrec
tly
XX
X
Dis
solv
ed a
ir
flota
tion
Insu
ffici
ent
trea
tmen
t due
to
impr
oper
ope
ratio
n
6.4.
33A
ir re
leas
e no
zzle
s no
t ke
pt c
lean
or b
lock
ages
no
t cle
ared
XX
X
Rapi
d sa
nd
filtr
atio
nIn
suffi
cien
t tr
eatm
ent d
ue to
im
prop
er d
esig
n
6.4.
34W
rong
cho
ice
or
inad
equa
te d
epth
of t
he
med
ia, w
rong
med
ia
spec
ifica
tions
XX
XRe
leas
e of
a v
arie
ty o
f ph
ysic
al, c
hem
ical
or
mic
robi
al im
puri
ties
into
trea
ted
wat
er
6.5
Rap
id s
and
filtr
atio
nH
ydra
ulic
lo
adIn
suffi
cien
t tr
eatm
ent d
ue to
a
high
hyd
raul
ic lo
ad
6.5.
1Su
dden
incr
ease
in w
ater
us
e (p
ipe
burs
t, fir
e, e
tc.)
with
insu
ffici
ent b
uffe
r ca
paci
ty
XX
X8
XX
Hyd
raul
ic
load
Insu
ffici
ent
trea
tmen
t due
to
vari
atio
ns in
flow
th
roug
h th
e fil
ters
du
ring
a fi
lter c
ycle
6.5.
2In
suffi
cien
t flo
w
equa
lizat
ion
desi
gned
in
to th
e sy
stem
or
impr
oper
hyd
raul
ic
cont
rol
XX
XX
Brea
kthr
ough
pea
ks
duri
ng th
e fil
ter c
ycle
, ch
anne
l for
min
g
Prev
ious
tr
eatm
ent
Insu
ffici
ent
trea
tmen
t due
to
high
par
ticle
load
in
inco
min
g w
ater
6.5.
3To
o hi
gh p
artic
le lo
ad d
ue
to s
ubop
timal
coa
gula
tion
in p
revi
ous
step
X1
or 2
XX
Brea
kthr
ough
of
part
icle
s, m
ud b
alls
Rapi
d sa
nd
filte
r
A 6. Treatment
- 38 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Back
was
hing
, cl
eani
ngIn
suffi
cien
t tr
eatm
ent d
ue to
im
prop
er o
r in
freq
uent
ba
ckw
ashi
ng
6.5.
4X
XX
Back
was
hing
, cl
eani
ngIn
suffi
cien
t tr
eatm
ent d
ue to
im
prop
er fi
lter
med
ia
6.5.
5Sa
nd n
ot re
plac
ed w
hen
requ
ired
XX
X
Back
was
hing
, cl
eani
ngIn
suffi
cien
t tr
eatm
ent d
ue to
im
prop
er w
ashi
ng
equi
pmen
t
6.5.
6Po
or p
erfo
rman
ce o
f air
sc
oure
rs, b
lock
ed n
ozzl
es,
unev
en d
istr
ibut
ion
of
wat
er a
nd a
ir
XX
XX
Brea
kthr
ough
of
prot
ozoa
or p
artic
les,
al
gal f
orm
atio
ns
Earl
y st
age
of
filte
r op
erat
ing
(afte
r w
ashi
ng)
Low
er re
mov
al
effic
ienc
y du
ring
th
e ea
rly
stag
e of
ra
pid
filte
r op
erat
ion
(filte
r ri
peni
ng)
6.5.
7Br
eakt
hrou
gh o
f pa
rtic
les
(incl
. e.g
. pa
rasi
tes)
into
dri
nkin
g w
ater
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
8D
eter
iora
tion,
err
atic
hy
drau
lic s
tres
sX
XX
XX
Con
tam
inan
ts in
fil
tere
d w
ater
Yes
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
9Fi
lter b
lock
age
XX
XX
Yes
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
10A
ir u
nder
neat
h th
e fil
ter
bed
due
to in
suffi
cien
t de
aera
tion
XX
XX
XYe
s
Pum
p an
d flu
e da
mpe
rFi
lter b
reak
age,
da
mag
e of
the
filte
r6.
5.11
Too
high
flow
due
to
failu
re o
f the
flue
dam
per
or th
e do
sing
pum
p
XX
XX
XYe
s
Filte
r bed
A 6. Treatment
- 39 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
12Re
duce
d cl
eani
ng
perf
orm
ance
due
to lo
w
back
was
h flo
w s
peed
, cl
eani
ng p
rogr
am fa
ilure
or
man
ual o
pera
tion
XX
XX
XYe
s
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
13C
lean
ing
air
cont
amin
ated
with
e.g
. fli
es, p
olle
n
XX
XX
Yes
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
14D
estr
uctio
n du
e to
pr
essu
re in
clo
sed
filte
r la
yers
rela
ted
to h
ydro
m
echa
nica
l sec
urity
de
vise
s or
pre
ssur
e-tr
ansd
ucer
s
XX
XX
XYe
s
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
15In
term
ixin
g of
sev
eral
la
yers
in
filte
rs w
hich
are
si
mul
tane
ousl
y cl
eane
d w
ith a
ir a
nd w
ater
XX
XX
Yes
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
6.5.
16Sh
ift in
the
part
icle
-siz
e di
stri
butio
nX
XX
XX
Yes
Redu
ced
filtr
atio
n pe
rfor
man
ce6.
5.17
Inap
prop
riat
e fil
trat
ion
spee
d, fi
lter m
ater
ial,
runn
ing
time,
laye
r th
ickn
ess
(e.g
. due
to
rapi
d ch
ange
s in
flow
, pr
essu
re, c
once
ntra
tions
)
XX
XX
XX
Con
tam
inan
ts in
fil
tere
d w
ater
Yes
Pum
p an
d flu
e da
mpe
r6.
5.18
Too
high
flow
due
to
failu
re o
f the
flue
dam
per
or th
e do
sing
pum
p
XX
XX
XX
Yes
Filte
r bed
A 6. Treatment
- 40 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Filte
r blo
ckag
e6.
5.19
Erra
tic d
istr
ibut
ion
of th
e cl
eani
ng m
edia
due
to
chan
ges
in th
e su
ppor
t la
yer o
r oth
er d
estr
uctio
n in
the
filte
r lay
ers
XX
XX
XX
Yes
Filte
r blo
ckag
e6.
5.20
Hyd
rolo
gica
l eve
nts
resu
lting
in c
hang
es o
f the
am
ount
of p
artic
les
in th
e ra
w w
ater
XX
XX
XX
Filte
r blo
ckag
e6.
5.21
Failu
re o
f the
floc
cula
tion
XX
XX
XX
X
Filte
r blo
ckag
e6.
5.22
Und
esir
ed p
artic
les
in th
e fil
ter d
ue to
failu
re o
f m
icro
sie
ves
or
inad
equa
te d
esig
n
XX
XX
XX
X
Filte
r blo
ckag
e6.
5.23
Redu
ced
clea
ning
pe
rfor
man
ce d
ue to
cl
eani
ng w
ater
flow
spe
ed
too
low
or f
ailu
re in
the
clea
ning
pro
gram
or i
n th
e m
anua
l cle
anin
g op
erat
ion
or w
ater
in th
e cl
eani
ng a
ir s
yste
m
XX
XX
XX
Yes
Filte
r blo
ckag
e6.
5.24
Cle
anin
g in
terv
als
too
long
or f
ailu
re o
f the
cl
eani
ng p
roce
dure
due
to
e.g.
blo
ckag
e of
the
nozz
les
or c
orro
sion
in th
e cl
eani
ng s
yste
m
XX
XX
XYe
s
Yes
Con
tam
inan
ts in
fil
tere
d w
ater
or/
and
redu
ced
avai
labi
lity
of
drin
king
wat
er
Filte
r bed
A 6. Treatment
- 41 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Filte
r blo
ckag
e6.
5.25
Dur
ing
inst
alla
tion
insu
ffici
ent f
lush
ing
afte
r th
e st
art u
p op
erat
ion
of
the
filte
r
XX
Yes
Filte
r blo
ckag
e6.
5.26
Insu
ffici
ent p
re-tr
eatm
ent
acco
rdin
g to
the
susp
ende
d pa
rtic
les
XX
XX
Yes
Filte
r blo
ckag
e6.
5.27
Shift
in th
e pa
rtic
le-s
ize
dist
ribu
tion
XX
XX
XYe
s
Insu
ffici
ent
elim
inat
ion
of fl
ocs
and/
or fl
occu
lant
s
6.5.
28D
estr
uctio
n of
the
flocs
X
XX
XX
Con
tam
inan
ts in
fil
tere
d w
ater
Yes
Pum
p an
d flu
e da
mpe
rTo
o lo
w fl
ow
6.5.
29Fa
ilure
of t
he fl
ue d
ampe
r or
the
dosi
ng p
ump
XX
XRe
duce
d av
aila
bilit
y of
dr
inki
ng w
ater
Yes
Con
tam
inat
ion
of
the
filte
r6.
5.30
Back
pres
sure
of t
he
clea
ning
wat
er d
ue to
no
pres
sure
free
cle
anin
g w
ater
out
let
XX
XX
XC
onta
min
ants
from
the
clea
ning
wat
er
(cle
anin
g ch
emic
als
or
raw
wat
er
cont
amin
ants
) in
the
filte
red
wat
er
Yes
Con
tam
inat
ion
of
the
filte
r6.
5.31
Erra
tic d
istr
ibut
ion
of th
e cl
eani
ng m
edia
resu
lting
in
uns
atis
fyin
g cl
eani
ng
chan
ge in
the
supp
ort
laye
r or o
ther
des
truc
tion
in th
e m
embr
ane
laye
rs
XX
XX
XYe
sC
onta
min
ants
in th
e fil
tere
d w
ater
Cle
anin
g sy
stem
A 6. Treatment
- 42 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Con
tam
inat
ion
of
the
filte
r6.
5.32
Con
tam
inan
ts o
f the
m
anuf
actu
ring
pro
cess
in
the
filte
r due
to
insu
ffici
ent c
lean
ing
afte
r in
stal
latio
n
XX
XX
Yes
Con
tam
inat
ion
of
the
wat
er
dow
nstr
eam
of t
he
filte
r
6.5.
33C
lean
ing
med
ia
cont
amin
ated
XX
XX
Yes
Con
tam
inat
ion
of
the
wat
er
dow
nstr
eam
of t
he
filte
r
6.5.
34C
lean
ing
air
cont
amin
ated
with
e.g
. fli
es, p
olle
n
XX
XX
Yes
Con
tam
inat
ion
of
the
wat
er
dow
nstr
eam
of t
he
filte
r
6.5.
35N
ot d
isca
rdin
g of
the
first
fil
trat
ed w
ater
afte
r the
cl
eani
ng
XX
XYe
s
Con
tam
inat
ion
of
the
wat
er
dow
nstr
eam
of t
he
filte
r
6.5.
36M
icro
biol
ogic
al a
ctiv
ity
due
to in
suffi
cien
t cl
eani
ng
XX
XX
Yes
Con
tam
inat
ion
of
the
wat
er
dow
nstr
eam
of t
he
filte
r
6.5.
37C
hem
ical
con
tam
inat
ion
dow
nstr
eam
of t
he fi
lter
due
to in
adeq
uate
sto
rage
of
che
mic
als
XX
XYe
s
Con
tam
inan
ts in
w
aste
wat
er6.
5.38
Inap
prop
riat
e cl
eani
ng
wat
er tr
eatm
ent
XX
XX
XEn
viro
nmen
tal
pollu
tion
Yes
Con
tam
inan
ts in
the
filte
red
wat
er
A 6. Treatment
- 43 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Dis
rupt
ion
of th
e fil
trat
ion
6.5.
39D
urin
g cl
eani
ng p
roce
ss
or m
aint
enan
ce o
r rep
air
in c
ombi
natio
n w
ith o
nly
one
exis
ting
filtr
atio
n-lin
e
XX
XN
o av
aila
bilit
y of
fil
tere
d w
ater
Yes
Refe
edin
g cl
eani
ng
wat
er
6.5.
40X
XA
ccum
ulat
ion
of
path
ogen
s in
the
trea
tmen
t
Yes
Failu
re o
f the
au
tom
atis
ed,
prog
ram
mab
le
cont
rol s
yste
m
6.5.
41Po
wer
failu
re,
prog
ram
mab
le e
rror
sX
XX
XX
XX
XSe
vera
l pos
sibi
litie
s de
pend
s on
the
kind
s of
failu
res
Yes
Staf
f get
ting
into
un
desi
red
cont
act
with
che
mic
als
6.5.
42In
adeq
uate
sto
rage
of
chem
ical
s X
XX
XH
ealth
impa
ct to
the
staf
fN
o
Failu
re o
f the
m
onito
ring
of t
he
rapi
d fil
ter
6.5.
43N
o m
anho
les
exis
ting
XD
elay
ed o
r no
dete
ctio
n of
filte
r fa
ilure
Failu
re o
f m
onito
ring
6.5.
44A
bsen
t or i
nsuf
ficie
nt
mon
itori
ng o
f the
pr
essu
re d
iffer
ence
and
op
erat
iona
l pre
ssur
e
XX
XX
XYe
s
Failu
re o
f m
onito
ring
6.5.
45In
suffi
cien
t num
ber o
f sa
mpl
es a
t a s
ampl
e po
int
and/
or d
urin
g a
defin
ed
peri
od o
f sam
plin
g
XX
Failu
re o
f m
onito
ring
6.5.
46In
appr
opri
ate
mon
itori
ng
conc
epts
X
Del
ayed
or n
o de
tect
ion
of
cont
amin
ants
in th
e fil
tere
d w
ater
, in
appr
opri
ate
oper
atio
n
Mon
itori
ng
A 6. Treatment
- 44 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Failu
re o
f m
onito
ring
6.5.
47M
alfu
nctio
ning
m
easu
ring
inst
rum
ent
due
to e
rror
s at
m
anuf
actu
ring
, ope
ratio
n or
mai
nten
ance
XX
6.6
Dis
infe
ctio
nC
hlor
inat
ion
Gas
ch
lori
natio
nC
hlor
ine
gas
leak
ages
6.6.
1C
hlor
inat
ion
faci
litie
s do
no
t com
ply
with
saf
ety
regu
latio
ns
XX
XX
Chl
orin
atio
nG
as
chlo
rina
tion
Una
vaila
bilit
y of
ch
lori
ne g
as6.
6.2
Leve
ls o
f gas
bot
tles
not
chec
ked,
new
bot
tles
not
orde
red
timeo
usly
.
XX
Chl
orin
atio
nD
osin
g sy
stem
Mal
func
tioni
ng
dosi
ng s
yste
ms
6.6.
3Er
rors
in c
hlor
ine
solu
tion
conc
entr
atio
n, b
lock
ages
XX
X
UV
di
sinf
ectio
nU
V la
mps
Too
low
UV
dos
e 6.
6.4
Dec
reas
e of
lam
p pe
rfor
man
ce d
ue to
ag
eing
or c
olou
r se
dim
ents
on
quar
tz tu
be.
Elec
tric
al d
isru
ptio
ns
XX
UV
or
chem
ical
di
sinf
ectio
n
Part
icle
s in
the
wat
er d
urin
g th
e di
sinf
ectio
n pr
oces
s
6.6.
5In
appr
opri
ate
pre-
trea
tmen
t X
XX
XC
onta
min
ants
(p
atho
gens
) in
the
disi
nfec
ted
wat
er
Yes
UV
or
chem
ical
di
sinf
ectio
n
Path
ogen
s ar
e pr
otec
ted
agai
nst
the
disi
nfec
tion
6.6.
6Pa
thog
ens
in a
ggre
gate
s w
ith m
ucus
XX
Con
tam
inan
ts
(pat
hoge
ns) i
n th
e di
sinf
ecte
d w
ater
Yes
UV
or
chem
ical
di
sinf
ectio
n
Failu
re o
f the
au
tom
atis
ed,
prog
ram
mab
le
cont
rol s
yste
m
6.6.
7Po
wer
failu
re,
prog
ram
mab
le e
rror
sX
XX
XX
XX
XSe
vera
l pos
sibi
litie
s de
pend
s on
the
kind
s of
failu
res,
Yes
A 6. Treatment
- 45 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
UV
or
chem
ical
di
sinf
ectio
n
Too
shor
t rea
ctio
n tim
e of
dis
infe
ctio
n ag
ents
in th
e w
ater
6.6.
8In
corr
ect d
osin
g lo
catio
nX
XX
Con
tam
inan
ts
(pat
hoge
ns) i
n th
e di
sinf
ecte
d w
ater
Yes
UV
di
sinf
ectio
nU
V la
mps
Impr
oper
in
stal
latio
n6.
6.9
Inco
rrec
t spe
cific
atio
ns o
f la
mps
XX
UV
di
sinf
ectio
nG
ener
alPo
wer
fluc
tuat
ions
6.6.
10N
o ba
ck-u
p po
wer
sup
ply
Ozo
ne
disi
nfec
tion
Gen
eral
Pow
er fl
uctu
atio
ns6.
6.11
No
back
-up
pow
er s
uppl
y
Ozo
ne
disi
nfec
tion
Air
co
mpr
esso
rFa
iling
air
co
mpr
esso
r6.
6.12
XX
X
Ozo
ne
disi
nfec
tion
Ozo
ne
gene
rato
rFa
iling
ozo
ne
gene
rato
r6.
6.13
XX
X
Ozo
ne
disi
nfec
tion
Ozo
ne
gene
rato
rFa
ilure
in o
zone
ge
nera
tor c
oolin
g sy
stem
6.6.
14
Ozo
ne
disi
nfec
tion
Ozo
ne g
as
met
erO
zone
dos
e to
o lo
w6.
6.15
Failu
re o
r wro
ng
calib
ratio
n O
zone
di
sinf
ectio
nD
isso
lved
oz
one
met
erO
zone
dos
e to
o lo
w6.
6.16
Failu
re o
r wro
ng
calib
ratio
n
Ozo
ne
disi
nfec
tion
Ozo
ne
tran
sfer
line
sLe
akag
e of
ozo
ne
gas
6.6.
17
Ozo
ne
disi
nfec
tion
Side
stre
am
pum
pIn
adeq
uate
ozo
ne
dosi
ng6.
6.18
Pum
p fa
ilure
Ozo
ne
disi
nfec
tion
Bubb
le
diffu
ser
Dec
reas
e in
ozo
ne
tran
sfer
effi
cien
cy6.
6.19
Diff
user
clo
ggin
g or
ga
sket
leak
age
Ozo
ne
disi
nfec
tion
Ozo
ne
cont
acto
rIn
suffi
cien
t di
sinf
ectio
n du
e to
in
adeq
uate
des
ign
6.6.
20In
suffi
cien
t con
tact
tim
e,
insu
ffici
ent o
xyge
n su
pply
A 6. Treatment
- 46 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Ozo
ne
disi
nfec
tion
Ozo
ne
cont
acto
rIn
suffi
cien
t di
sinf
ectio
n6.
6.21
Unu
sual
ly h
igh
cont
ent o
f or
gani
c m
atte
r in
raw
w
ater
XX
Ozo
ne
disi
nfec
tion
Ozo
ne
cont
acto
rIn
suffi
cien
t di
sinf
ectio
n6.
6.22
Due
to w
ater
usa
ge
exce
edin
g de
sign
flow
XX
Ozo
ne
disi
nfec
tion
Ozo
ne
cont
acto
rIn
suffi
cien
t di
sinf
ectio
n6.
6.23
Brom
ide
cont
ent i
n th
e ra
w w
ater
XX
Form
atio
n of
bro
mat
e
Ozo
natio
nFo
rmat
ion
of D
BP6.
6.24
Brom
ide
cont
ent i
n th
e ra
w w
ater
XX
XC
onta
min
ants
in th
e di
sinf
ecte
d w
ater
No
Ozo
natio
nIn
com
plet
e di
sinf
ectio
n6.
6.25
Turb
idity
due
to fa
ilure
of
the
pre-
trea
tmen
t X
XC
onta
min
ants
(p
atho
gens
) in
the
disi
nfec
ted
wat
er
No
6.7
Mem
bran
e fi
ltrat
ion
Mem
bran
e m
odul
e/ p
lant
Des
truc
tion
of
mem
bran
e m
odul
es6.
7.1
Stru
ctur
al d
amag
es, e
.g.
due
to p
ress
ure
shoc
ks,
cros
sflo
ws,
che
mic
al
dam
ages
or b
roke
n fib
res.
XX
XX
XX
XN
o av
aila
bilit
y of
dr
inki
ng w
ater
and
/or
cont
amin
ants
in fi
ltere
d w
ater
Mem
bran
e pr
oces
sRe
duce
d fil
trat
ion
perf
orm
ance
6.
7.2
Ope
ratio
nal f
ault
with
au
tom
atis
ed p
roce
ss b
y un
qual
ified
sta
ff
XX
XX
XX
XRe
duce
d av
aila
bilit
y of
dr
inki
ng w
ater
and
/or
cont
amin
ants
in fi
ltere
d w
ater
Yes
Mem
bran
e6.
7.3
Cha
nge
in q
ualit
y of
raw
w
ater
or i
ncom
ing
wat
er
(e.g
. sto
rm, a
bsen
ce o
f or
failu
re in
the
pre-
trea
tmen
t)
XX
XX
XRe
duce
d av
aila
bilit
y of
dr
inki
ng w
ater
and
/or
cont
amin
ants
in fi
ltere
d w
ater
Mem
bran
e/
Cle
anin
g pr
oces
s
6.7.
4In
adeq
uate
cle
anin
g m
etho
ds in
com
bina
tion
with
hig
h co
ncen
trat
ion
of c
onta
min
ants
XX
Red
uced
cap
acity
Mem
bran
e fo
ulin
g
A 6. Treatment
- 47 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Mem
bran
e6.
7.5
Erra
tic h
ydra
ulic
str
ess,
de
teri
orat
ion,
in
appr
opri
ate
mem
bran
e m
ater
ial,
exce
edin
g th
e m
axim
um p
ress
ure
due
to
faul
t in
the
prog
ram
XX
XX
XX
Yes
Mem
bran
e6.
7.6
Con
tam
inat
ed w
ater
by
acci
dent
al p
ollu
tion
like
indu
stri
al h
azar
ds, t
ruck
w
ith d
ange
rous
goo
ds
XX
XX
Mem
bran
e6.
7.7
Con
tam
inat
ed w
ater
by
delib
erat
e po
llutio
n lik
e te
rror
ist a
ttack
s
XX
XX
Mem
bran
e/M
onito
ring
sy
stem
6.7.
8A
bsen
t or i
nsuf
ficie
nt
mon
itori
ng o
f TM
P,
pres
sure
and
flow
XX
XX
X
Mem
bran
e/C
lea
ning
pro
cess
6.7.
9In
corr
ect d
osag
e of
ch
emic
als
for c
lean
ing
(e.g
. bec
ause
of e
rror
s in
cl
eani
ng p
roto
col)
XX
XX
XC
onta
min
ants
and
cl
eani
ng c
hem
ical
s in
fil
tere
d w
ater
Mem
bran
e6.
7.10
Larg
e pa
rtic
les
due
to
inad
equa
te p
re-tr
eatm
ent
(no
or w
rong
filte
r)
XX
XX
X
Mem
bran
e/C
lea
ning
pro
cess
6.7.
11Pr
essu
re o
f the
bac
kflu
sh
is to
o hi
gh (f
or c
apill
arie
s)X
XX
XX
Mem
bran
e br
eakt
hrou
gh, f
ibre
br
eaka
ge
Con
tam
inan
ts in
fil
tere
d w
ater
Mem
bran
e da
mag
e
A 6. Treatment
- 48 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Mem
bran
eM
embr
ane
impe
rfec
tions
6.
7.12
Man
ufac
ture
def
icie
ncie
s:
faul
ty b
arri
er la
yer
coat
ing
+ p
olym
eris
atio
n,
glue
line
dis
cont
inui
ties,
in
adeq
uate
ly s
ealin
g th
e ed
ges
of m
embr
ane
leav
es
XX
XX
Con
tam
inan
ts in
fil
tere
d w
ater
O-r
ing,
glu
e lin
esRa
w w
ater
byp
ass
6.7.
13Fa
ilure
of o
-rin
g or
glu
e-lin
e ca
used
by
e.g.
cut
s,
crac
ks, l
eaks
from
im
prop
er in
stal
latio
n an
d sh
imm
ing
XX
XX
Con
tam
inan
ts in
fil
tere
d w
ater
Out
let o
f m
embr
ane
6.7.
14Ba
cter
ial g
row
th o
n pe
rmea
te s
ide
X
Pipe
sys
tem
, in
tern
al
surf
aces
6.7.
15Ba
cter
ial g
row
th o
n in
tern
al s
urfa
ces
X
Mem
bran
e/
Cle
anin
g pr
oces
s
Con
tam
inat
ion
of
the
wat
er
dow
nstr
eam
of t
he
mem
bran
e
6.7.
16N
o di
scar
d of
the
first
fil
trat
ed w
ater
afte
r the
cl
eani
ng
XX
XC
onta
min
ants
(TH
M
and
AO
X) i
n fil
tere
d w
ater
Yes
Mem
bran
e/C
lea
ning
pro
cess
Wea
r at m
embr
ane
com
pone
nts
6.7.
17Fr
eque
nt b
ackw
ashi
ngX
XX
XX
Con
tam
inan
ts in
fil
tere
d w
ater
Mem
bran
e/
Cle
anin
g pr
oces
s
DBP
6.7.
18D
isin
fect
ion
of th
e m
embr
ane
XX
Con
tam
inan
ts (D
BPs)
in
filte
red
wat
er
Yes
Bact
eria
to tr
eate
d w
ater
Con
tam
inan
ts (m
icro
or
gani
sms)
in fi
ltere
d w
ater
A 6. Treatment
- 49 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Mem
bran
e/
chem
ical
sC
onta
min
atio
n of
th
e w
ater
do
wns
trea
m o
f the
fil
ter
6.7.
19St
ored
che
mic
als
rele
ased
in
to th
e w
ater
do
wns
trea
m o
f the
filte
r du
e to
val
ve fa
ilure
XX
XX
Hea
lth d
amag
e of
the
staf
f, co
ntam
inan
ts in
th
e w
ater
Yes
Mem
bran
e/
Pneu
mat
ic
syst
em
6.7.
20Po
wer
failu
re
Mem
bran
e/
Pneu
mat
ic
syst
em
6.7.
21Le
akag
e in
the
air s
uppl
y sy
stem
Mem
bran
e pr
oces
s/
Elec
tron
ic
syst
em
Failu
re o
f the
au
tom
atis
ed,
prog
ram
mab
le
cont
rol s
yste
m
6.7.
22Po
wer
failu
re,
prog
ram
mab
le e
rror
sX
XSe
vera
l pos
sibi
litie
s de
pend
s on
the
kind
s of
failu
res
Pipe
sys
tem
Bu
rst o
f pip
es6.
7.23
Plug
ging
due
to a
lgal
bl
oom
, art
efac
ts,
accu
mul
atio
n
XX
XX
Redu
ced
avai
labi
lity
of
drin
king
wat
er
Pum
psPu
mp
failu
re6.
7.24
Wea
r, w
rong
des
ign
XX
No
wat
er p
rodu
ctio
nM
embr
ane
filtr
atio
n m
onito
ring
Mon
itori
ng fa
ilure
of
the
mem
bran
e6.
7.25
No
part
icle
cou
nter
or
bubb
le te
st, p
ress
ure
deca
y te
st
XD
elay
ed o
r no
dete
ctio
n of
mem
bran
e fa
ilure
Mem
bran
e fil
trat
ion
mon
itori
ng
6.7.
26In
suffi
cien
t num
ber o
f sa
mpl
es a
t a s
ampl
e po
int
and/
or d
urin
g a
defin
ed
peri
od o
f sam
plin
g
XX
Mem
bran
e fil
trat
ion
mon
itori
ng
6.7.
27In
appr
opri
ate
mon
itori
ng
conc
epts
X
Failu
re o
f the
m
onito
ring
of:
phys
ical
(e.g
. tu
rbid
ity, f
low
, TM
P),
biol
ogic
al
para
met
ers
(e.g
. pa
rasi
tes)
, pre
ssur
e,
chem
ical
pa
ram
eter
s
Del
ayed
or n
o de
tect
ion
of
cont
amin
ants
in th
e fil
tere
d w
ater
Redu
ced
avai
labi
lity
of
drin
king
wat
er a
nd/o
r co
ntam
inan
ts in
filte
red
wat
er
Failu
re o
f the
co
mpr
esso
r/th
e pn
eum
atic
sys
tem
A 6. Treatment
- 50 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Mem
bran
e fil
trat
ion
mon
itori
ng
6.7.
28M
alfu
nctio
n of
mea
suri
ng
inst
rum
ents
due
to
mis
take
s in
m
anuf
actu
ring
pro
cess
, w
rong
ope
ratio
n sy
stem
or
mai
nten
ance
, mea
sure
-lin
e ru
ns d
ry
XX
Mem
bran
e fil
trat
ion
mon
itori
ng
6.7.
29Po
wer
failu
reX
X
Mem
bran
e fil
trat
ion
mon
itori
ng
6.7.
30Sa
mpl
ing
duri
ng th
e fil
trat
ion
qual
ity v
arie
dX
6.8
Slow
san
d fi
ltrat
ion
Slow
filte
rD
isru
ptio
n of
the
filtr
atio
n 6.
8.1
Dur
ing
clea
ning
pro
cess
or
mai
nten
ance
or r
epai
r in
com
bina
tion
with
onl
y on
e ex
istin
g fil
trat
ion-
line
XX
No
avai
labi
lity
of
drin
king
wat
erYe
s
Slow
filte
r6.
8.2
Inap
prop
riat
e fil
trat
ion
spee
d, fi
lter m
ater
ial,
runn
ing
time,
cle
anin
g,
laye
r thi
ckne
ss, f
ilter
ad
just
men
t, in
suffi
cien
t re
mov
al o
f the
top
laye
r
XX
XX
XX
Yes
Slow
filte
r6.
8.3
Inap
prop
riat
e ad
just
men
ts d
urin
g st
art
up p
hase
XX
XX
XYe
s
para
met
ers
Redu
ced
filtr
atio
n pe
rfor
man
ceRe
duce
d av
aila
bilit
y of
dr
inki
ng w
ater
A 6. Treatment
- 51 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Slow
filte
r/
mon
itori
ng6.
8.4
Abs
ent o
r ins
uffic
ient
m
onito
ring
of p
ress
ure
diffe
renc
es a
nd
oper
atio
nal p
ress
ure
XX
XX
XYe
s
Slow
filte
r6.
8.5
Due
to q
ualit
y of
raw
or
inco
min
g w
ater
: un
desi
red
part
icle
s/co
ntam
inan
ts in
th
e fil
ter d
ue to
failu
re o
f m
icro
sie
ves
or th
e bo
rder
, abs
ence
of a
pre
-tr
eatm
ent o
r ina
dequ
ate
desi
gn
XX
XX
XX
XYe
s
Slow
filte
r6.
8.6
Due
to q
ualit
y of
raw
or
inco
min
g w
ater
: hig
h tu
rbid
ity d
ue to
the
abse
nce
of a
co
rres
pond
ing
pre-
trea
tmen
t
XX
XX
XX
Yes
Slow
filte
r6.
8.7
Hyd
rolo
gica
l eve
nts
resu
lting
in c
hang
es o
f the
am
ount
of p
artic
les
in th
e ra
w w
ater
XX
XX
XX
Yes
Slow
filte
r6.
8.8
Oth
er s
ubst
ance
s w
ithin
in
com
ing
wat
er, s
uch
as
alga
e, e
leva
ted
Fe, M
n,
prec
ipita
tion
of li
me,
fr
eeze
, dus
t
XX
Yes
Slow
filte
r6.
8.9
Det
erio
ratio
n, e
rrat
ic
hydr
aulic
str
ess
XX
XX
XYe
s
Filte
r blo
ckag
e
Redu
ced
avai
labi
lity
of
drin
king
wat
er
Filte
r bre
akag
e,
dam
age
of th
e fil
ter
Con
tam
inan
ts in
fil
tere
d w
ater
A 6. Treatment
- 52 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Slow
filte
r6.
8.10
Due
to q
ualit
y of
raw
or
inco
min
g w
ater
: un
desi
red
part
icle
s/co
ntam
inan
ts in
th
e fil
ter d
ue to
failu
re o
f m
icro
sie
ves
or f
ine
scre
ens,
abs
ence
of a
pre
-tr
eatm
ent o
r ina
dequ
ate
desi
gn
XX
XX
XX
XYe
s
Slow
filte
r6.
8.11
Rum
plin
g of
the
filtr
atio
n la
yer d
ue to
sm
all a
nim
als
or in
sect
s in
the
filte
r
XX
XX
XX
Yes
Slow
filte
r6.
8.12
Dis
turb
ance
of m
icro
bial
fa
una
in th
e fil
ter d
ue to
fa
st c
hang
e in
co
ncen
trat
ions
, pH
, dry
ru
ns e
tc.
XX
XX
XYe
s
Slow
fil
ter/
Out
let
6.8.
13O
utw
ashi
ng o
f filt
er
orga
nism
s du
e to
hig
h hy
drau
lic s
tres
s, la
ckin
g de
vice
for r
eten
tion
XX
XX
XX
Yes
Slow
filte
r/
mon
itori
ng6.
8.14
Abs
ent o
r ins
uffic
ient
m
onito
ring
of t
he
pres
sure
diff
eren
ce a
nd
oper
atio
nal p
ress
ure
XX
XX
XYe
s
Slow
fil
ter/
over
flow
pip
e an
d fr
eebo
ard
Ove
rflo
win
g of
the
filte
r6.
8.15
Bloc
king
of t
he o
verf
low
pi
pe, e
xtre
me
rain
falls
, to
o lo
w fr
eebo
ard
XX
XX
XD
amag
e ca
used
by
the
over
flow
ing
wat
erN
o
A 6. Treatment
- 53 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Type
of h
azar
dous
ev.
Clu
ster
of
elem
ents
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Slow
filtr
atio
n m
onito
ring
6.8.
16In
suffi
cien
t num
ber o
f sa
mpl
es a
t a s
ampl
e po
int
and/
or d
urin
g a
defin
ed
peri
od o
f sam
plin
g
XX
Slow
filtr
atio
n m
onito
ring
6.8.
17In
appr
opri
ate
mon
itori
ng
conc
epts
X
Slow
filtr
atio
n m
onito
ring
6.8.
18M
alfu
nctio
n of
mea
suri
ng
inst
rum
ents
due
to
man
ufac
tura
l def
icie
ncie
s, w
rong
ope
ratio
n sy
stem
or
mai
nten
ance
XX
Slow
filtr
atio
n m
onito
ring
6.8.
19Po
wer
failu
reX
X
Slow
filtr
atio
n m
onito
ring
6.8.
20Sa
mpl
ing
duri
ng th
e fil
trat
ion
qual
ity v
arie
dX
Failu
re o
f the
m
onito
ring
of:
phys
ical
(e.g
. tu
rbid
ity, f
low
),
biol
ogic
al
para
met
ers
(e.g
. pa
rasi
tes)
, pre
ssur
e,
chem
ical
pa
ram
eter
s
Del
ayed
or n
o de
tect
ion
of
cont
amin
ants
in th
e fil
tere
d w
ater
A 6. Treatment
- 54 -
7. R
eser
voir
s an
d pu
mps
(eith
er d
irec
tly a
fter
trea
tmen
t or i
n th
e di
stri
butio
n sy
stem
)El
abor
ated
by:
Kiw
a W
ater
Res
earc
h
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
7.1
Cle
ar W
ater
rese
rvoi
rD
estr
uctio
n of
re
serv
oir b
y ex
trem
e ci
rcum
stan
ces
7.1.
1M
assi
ve g
roun
d m
ovem
ent,
near
traf
fic
acci
dent
s, e
xplo
sive
s et
c
XX
XX
Com
plet
e lo
ss o
f fun
ctio
n8
7.1.
2In
trod
uctio
n of
toxi
c m
ater
ial b
y sa
bota
ge o
r te
rror
ist a
ctio
n
XX
XX
Con
tam
inat
ed w
ater
8
7.1.
3In
trod
uctio
n of
pol
luta
nts
by im
prop
er u
se o
f m
ater
ial o
r ope
ratio
nal
erro
rs
XX
XX
XC
onta
min
ated
wat
er8
Long
resi
denc
e tim
e in
rese
rvoi
r7.
1.4
Dea
d co
rner
s in
rese
rvoi
rX
XD
ecre
ase
wat
er q
ualit
y8
Acc
umul
atio
n of
Se
dim
ent
7.1.
5In
suffi
cien
t cle
anin
g an
d/or
sed
imen
t loa
d in
in
com
ing
wat
er
XX
XX
Eros
ion
of s
edim
ent l
eadi
n g
to w
ater
qua
lity
prob
lem
s8
7.1.
6C
rack
s in
rese
rvoi
r wal
l in
com
bina
tion
with
pol
lute
d so
il
XX
XX
Con
tam
inat
ed w
ater
8
7.1.
7C
rack
s in
rese
rvoi
r roo
fX
XX
XC
onta
min
ated
wat
er8
7.1.
8Bl
ocke
d fil
ters
in
vent
ilatio
n in
com
bina
tion
with
und
erpr
essu
re in
re
serv
oir
XX
XC
onta
min
ated
wat
er8
Rese
rvoi
r vo
lum
e
Con
tam
inat
ion
of
wat
er
Con
stru
ctio
nC
onta
min
atio
n of
w
ater
by
entr
ance
of
pollu
tant
s
Gen
eral
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 7. Reservoirs and pumps
- 55 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Dam
age
to re
serv
oir
due
to h
igh
inte
rnal
pr
essu
re
7.1.
9Bl
ocke
d fil
ters
in
vent
ilatio
n du
e to
lack
of
clea
ning
XX
XX
Dam
age
to c
onst
ruct
ion
8
Ven
tilat
ion
and
open
ings
Con
tam
inat
ion
of
wat
er b
y en
tran
ce o
f po
lluta
nts
thro
ugh
open
ings
7.1.
10O
peni
ngs
in a
ir fi
lters
of
vent
ilatio
n, o
ther
hol
es o
r do
ors
XX
XC
onta
min
ated
wat
er8
Coa
ting
on
wal
lsC
onta
min
atio
n of
w
ater
by
grow
th o
f bi
olog
ical
mat
eria
l or
fung
i on
rese
rvoi
r w
all
7.1.
11G
row
th o
f bio
logi
cal
mat
eria
l or f
ungi
on
rese
rvoi
r wal
l due
to
Insu
ffici
ent c
lean
ing
and/
or im
prop
er c
oatin
g
XX
XC
onta
min
ated
wat
er8
Mea
sure
men
tV
olum
e of
w
ater
/wat
er le
vel i
n re
serv
oir i
s no
t m
easu
red
corr
ectly
7.1.
12Er
ror o
f met
erin
g de
vice
or
data
pro
cess
ing
XX
XW
rong
set
ting
for p
umps
, w
rong
pre
ssur
e in
net
wor
k8
7.2
Pum
ping
sta
tion
Con
trol
of
pum
psIn
corr
ect p
ump
setti
ngs
7.2.
1Im
prop
er o
pera
tion
or
failu
reX
XX
XX
Loss
of p
ress
ure/
flow
8
Pum
psFa
ll-ou
t of p
umps
7.2.
2El
ectr
ical
fall-
out a
nd
impr
oper
func
tioni
ng o
f ba
ckup
pow
er s
uppl
y
XX
XX
XX
Loss
of p
ress
ure/
flow
8
Surg
e ta
nkPr
essu
re tr
ansi
ents
ar
e no
t lev
elle
d ou
t7.
2.3
Abs
ence
or m
al
func
tioni
ng s
urge
tank
XX
XX
XEx
trem
e hi
gh o
r low
pr
essu
res
in n
etw
ork
8
A 7. Reservoirs and pumps
- 56 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Pres
sure
m
easu
rem
ent
Inco
rrec
t pre
ssur
e re
cord
ing
at
pum
ping
sta
tion
or
exte
rnal
loca
tions
7.2.
4Er
ror o
f met
erin
g de
vice
or
data
pro
cess
ing
XX
XX
XW
rong
set
ting
for p
umps
, lo
w p
ress
ure
in n
etw
ork
8
Pow
er b
ack-
up d
oes
not s
tart
7.2.
5Fa
iling
pow
er b
ack-
upX
XX
No
wat
er s
uppl
y du
ring
po
wer
inte
rrup
tions
8
Pow
er b
ack-
up w
ith
inco
rrec
t vol
tage
or
freq
uenc
y
7.2.
6Fa
iling
pow
er b
ack-
upX
XX
No
or m
alfu
nctio
ning
wat
er
supp
ly d
urin
g po
wer
in
corr
ectn
ess
8
Air
dry
erFa
iling
air
dry
er,
caus
ing
high
hu
mid
ity
7.2.
7Fa
iling
air
dry
erX
XX
Rapi
d co
rros
ion;
de
teri
orat
ion
of e
lect
roni
c co
mpo
nent
s
No
7.3
Val
ves
(bot
h in
rese
rvoi
rs a
s in
pum
ping
sta
tions
Wat
er le
akin
g th
roug
h va
lves
7.3.
1Im
prop
er d
esig
n or
op
erat
ion
XX
XX
XLo
ss o
f wat
er, i
neffi
cien
t pu
mpi
ng o
r mix
ing
of
diffe
rent
wat
er q
ualit
ies
8
Wat
er
(con
tam
inat
ed)
ente
ring
cle
ar w
ater
sy
stem
7.3.
2Im
prop
er d
esig
n or
op
erat
ion
XX
XX
XC
onta
min
ated
wat
er8
Pow
er b
ack-
up
Val
ves
A 7. Reservoirs and pumps
- 57 -
8. T
rans
port
and
dis
trib
utio
n (f
rom
trun
k m
ain
to th
e w
ater
met
er)
Elab
orat
ed b
y: K
iwa
Wat
er R
esea
rch
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
8.1
Net
wor
kW
ater
ent
erin
g th
e di
stri
butio
n
netw
ork
is p
ollu
ted
8.1.
1Tr
eatm
ent f
ailu
reX
03 -
07X
XSu
pply
of p
ollu
ted
wat
er to
cu
stom
ers
9
No/
insu
ffici
ent
wat
er s
uppl
y fr
om
pum
ps
8.1.
2Pu
mp
or re
serv
oir f
ailu
reX
03 -
07X
No/
insu
ffici
ent w
ater
su
pply
to c
usto
mer
s9
Con
tam
inat
ion
intr
oduc
ed d
urin
g re
pair
s
8.1.
3Po
or h
ygie
ne d
urin
g re
pair
sX
XX
Supp
ly o
f pol
lute
d w
ater
to
cust
omer
s9
8.1.
4Ba
d co
nditi
on o
f pip
eX
XX
XX
XN
o/in
suffi
cien
t sup
ply;
su
pply
of p
ollu
ted
wat
er to
cu
stom
ers;
ext
erna
l dam
age
to p
erso
ns b
uild
ings
etc
9
8.1.
5In
crea
sed
stre
sses
on
pipe
(g
roun
d, tr
affic
, hig
h pr
essu
res,
etc
) in
com
bina
tion
with
a
redu
ced
pipe
con
ditio
n
XX
X08
XX
XX
XN
o/in
suffi
cien
t sup
ply;
su
pply
of p
ollu
ted
wat
er to
cu
stom
ers;
ext
erna
l dam
age
to p
erso
ns b
uild
ings
etc
9
8.1.
6Ex
trem
e st
ress
es o
n pi
pe
(land
slid
es, t
raffi
c in
cide
nts,
sto
rms,
etc
)
XX
XX
XX
No/
insu
ffici
ent s
uppl
y;
supp
ly o
f pol
lute
d w
ater
to
cust
omer
s
9
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Refe
renc
eH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.El
emen
t
Gen
eral
Pipe
sPi
pe b
urst
Haz
ard
A 8. Drinking water transport and distribution
- 58 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Refe
renc
eH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.El
emen
tH
azar
d
Influ
x of
pol
lute
d w
ater
8.1.
7Lo
w (n
egat
ive)
pre
ssur
e in
ne
twor
k, in
com
bina
tion
with
leak
s or
leak
ing
join
ts
XX
XX
XSu
pply
of p
ollu
ted
wat
er to
cu
stom
ers
9
Incr
ease
of h
ardn
ess
8.1.
8D
eter
iora
tion
of c
emen
t lin
ing
caus
ing
incr
ease
of
hard
ness
XSu
pply
of h
ard
wat
er to
cu
stom
ers,
dam
age
to
elec
tric
al e
quip
men
t (b
oile
rs, e
tc)
9
Resu
spen
sion
of
sedi
men
t or
slou
ghin
g of
bio
film
8.1.
9Se
dim
enta
tion
of p
artic
les
or fo
rmat
ion
of b
iofil
m, i
n co
mbi
natio
n w
ith e
xtre
me
flow
s
XX
XX
XX
Supp
ly o
f pol
lute
d w
ater
to
cust
omer
s (d
isco
lour
ed
wat
er)
9
Pipe
s, jo
ints
Mig
ratio
n of
org
anic
po
lluta
nts
thro
ugh
pipe
wal
l (PE
or
PVC
) or r
ubbe
r jo
ints
8.1.
10O
rgan
ic p
ollu
tion
in
grou
ndX
XX
Supp
ly o
f pol
lute
d w
ater
to
cust
omer
s9
Met
al p
ipes
Rele
ase
of m
etal
lic
com
poun
ds8.
1.11
Det
erio
ratin
g lin
ing
in
met
al p
ipes
, low
pH
of
dist
ribu
ted
wat
er
XX
X03
- 07
XSu
pply
of p
ollu
ted
wat
er to
cu
stom
ers
9
Bitu
mic
pip
es,
join
tsRe
leas
e of
org
anic
co
mpo
unds
(PA
H)
8.1.
12D
eter
iora
tion
of b
itum
en
linin
g, e
spec
ially
coa
l tar
bi
tum
ic li
ning
XX
XX
Supp
ly o
f pol
lute
d w
ater
to
cust
omer
s9
Serv
ice
conn
ectio
ns,
fire
hydr
ants
Con
tam
inat
ion
of
wat
er b
y te
rror
ist
actio
n
8.1.
13In
trod
uctio
n of
toxi
c su
bsta
nces
by
sabo
tage
or
terr
oris
t act
ion
XX
XX
XX
Supp
ly o
f tox
ic w
ater
to
cust
omer
s; s
top
of s
uppl
y;
mas
s hy
ster
ia
9
A 8. Drinking water transport and distribution
- 59 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Refe
renc
eH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.El
emen
tH
azar
d
8.1.
14M
alfu
nctio
ning
val
ves,
co
nnec
tions
to d
iffer
ent
wat
er q
ualit
ies
(indu
stri
al
wat
er, s
ewer
s)
XX
XX
XX
Supp
ly o
f pol
lute
d w
ater
to
cust
omer
s9
8.1.
15V
alve
box
es in
unda
ted
with
con
tam
inat
ed w
ater
an
d im
prop
er s
ealin
g of
va
lve
XX
XX
XSu
pply
of p
ollu
ted
wat
er to
cu
stom
ers
9
Val
ve d
oes
not o
pen
or c
lose
8.1.
16M
alfu
nctio
ning
val
veX
XX
XX
XPr
oble
ms
with
ope
ratio
n ne
twor
k, n
o co
ntro
l in
case
of
em
erge
ncy
9
Fire
hyd
rant
Insu
ffici
ent w
ater
for
fire
fight
ing
8.1.
17M
alfu
nctio
ning
fire
hy
dran
t, re
duce
d av
aila
ble
capa
city
of w
ater
XX
XX
Fire
figh
ting
is h
inde
red
9
Fire
hyd
rant
Inflo
w o
f pol
luta
nts
pres
ent i
n hy
dran
t 8.
1.18
No
back
flow
pro
tect
ion
in
fire
hydr
ant a
nd im
prop
er
use
by fi
re b
riga
des
XX
XX
XX
Pollu
tion
of n
etw
ork
and
supp
ly o
f pol
lute
d w
ater
to
cust
omer
s
9
Serv
ice
conn
ectio
nsIn
flow
of p
ollu
tant
s fr
om c
onne
ctio
ns8.
1.19
Abs
ence
or m
al
func
tioni
ng b
ackf
low
pr
even
tion
(e. g
. non
-ret
urn
valv
e)
XX
XX
XPo
llutio
n of
net
wor
k9
Val
ves
Con
tam
inat
ion
ente
rs n
etw
ork
at
valv
es
A 8. Drinking water transport and distribution
- 60 -
9. In
tern
al p
ipin
gEl
abor
ated
by:
Kiw
a W
ater
Res
earc
h
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
9.1
Dri
nkin
g w
ater
inst
alla
tion
Low
flow
/ p
ress
ure
9.1.
1Ba
d de
sign
or l
ow
pres
sure
in d
istr
ibut
ion
netw
ork
XX
8X
Insu
ffici
ent s
uppl
y of
wat
er10
Back
flow
to
dist
ribu
tion
netw
ork
or o
ther
par
ts o
f in
stal
latio
n
9.1.
2W
rong
pro
tect
ion
mea
sure
s (e
.g. m
issi
ng o
r m
alfu
nctio
nin g
non
-ret
urn
valv
es),
or c
ross
-co
nnec
tions
XX
XX
XC
onta
min
atio
n of
di
stri
butio
n ne
twor
k or
in
stal
latio
n
10
Extr
eme
high
te
mpe
ratu
re o
f w
ater
from
tap
9.1.
3Fa
iling
hot
wat
er v
alve
s or
w
rong
inst
alla
tion
of
heat
er
XX
XBu
rnin
g10
9.1.
4C
lose
dis
tanc
e of
pip
e to
w
arm
obj
ects
, e.g
. cen
tral
he
atin
g
XX
Mic
robi
olog
ical
co
ntam
inat
ion,
e.g
. le
gion
ello
sis
10
9.1.
5D
ead
ends
in in
stal
latio
nX
XM
icro
biol
ogic
al
cont
amin
atio
n, e
.g.
legi
onel
losi
s
10
Mic
robi
olog
ical
pr
oble
ms
9.1.
6Ba
d di
sinf
ectio
n af
ter
inst
alla
tion
or re
pair
XX
Mic
robi
olog
ical
co
ntam
inat
ion
10
Noi
se in
pip
es9.
1.7
Wat
er h
amm
er a
nd/o
r hi
gh v
eloc
ities
XX
Nui
sanc
e to
cus
tom
ers
10
Mic
robi
olog
ical
pr
oble
ms
9.1.
8Po
llutio
n by
dev
ices
in th
e in
stal
latio
n e.
g. fi
lters
, so
ftene
rs e
tc.
XX
Mic
robi
olog
ical
co
ntam
inat
ion
10
Mat
eria
ls:
pipe
s, fi
tting
s an
d ta
p
Hig
h m
etal
rele
ase,
re
leas
e of
toxi
c ag
ents
9.1.
9Im
prop
er m
ater
ial o
r low
pH
X
X6
XX
Supp
ly o
f pol
lute
d w
ater
to
cust
omer
s10
Refe
renc
e
Gen
eral
Mic
robi
olog
ical
gr
owth
e.g
. le
gion
ella
Elem
ent
Haz
ard
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Haz
ardo
us e
vent
Type
of h
azar
dous
ev.
A 9. Internal piping
- 61 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dH
azar
dous
eve
ntTy
pe o
f haz
ardo
us e
v.
Mat
eria
ls:
pipe
s, fi
tting
s an
d ta
p
Leak
age
9.1.
10Po
or m
ater
ial,
high
pr
essu
res,
wat
er h
amm
er,
exte
rnal
e.g
. dri
lling
ac
tiviti
es
XX
XX
8X
XLe
akag
e of
wat
er10
War
m w
ater
re
serv
oirs
Sca
ling
9.1.
11H
igh
hard
ness
of w
ater
X6
XD
amag
e to
hea
ting
equi
pmen
t; nu
isan
ce to
cu
stom
ers
10
A 9. Internal piping
- 62 -
10. C
onsu
mer
and
taps
(inc
ludi
ng c
omm
unal
taps
)El
abor
ated
by:
WRC
SA
/ S
WU
E
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
10.1
Wat
er c
olle
ctio
n10
.1.1
Una
vaila
bilit
y of
wat
er
from
dis
trib
utio
n ne
twor
kX
X8
X
Una
vaila
bilit
y of
wat
er fo
r ho
useh
old
purp
oses
Not
re
leva
nt
10.1
.2V
anda
lism
or i
mpr
oper
us
e of
sta
ndpi
pe o
r tap
sX
X
X
U
nava
ilabi
lity
of w
ater
for
hous
ehol
d pu
rpos
esN
ot
rele
vant
Con
tam
inat
ion
of
tap
or s
urro
undi
ng
part
s
10.1
.3U
nhyg
ieni
c ha
ndlin
g of
ta
p e.
g. b
y un
was
hed
hand
s or
pre
senc
e of
an
imal
s
X
X
Spre
ad o
f dis
ease
s su
ch a
s ch
oler
a, h
epat
itis
A,
typh
oid,
dys
ente
ry a
nd
gast
roin
test
inal
infe
ctio
ns
Not
re
leva
nt
Com
mun
al
stan
dpip
es o
r gr
ound
tank
s
Una
vaila
bilit
y of
w
ater
10.1
.4N
o ac
cess
or p
oor a
cces
s to
th
e st
andp
ipe
or g
roun
d ta
nk d
ue to
obs
truc
tions
or
othe
r rea
sons
XX
XX
Una
vaila
bilit
y of
wat
er fo
r ho
useh
old
purp
oses
Not
re
leva
nt
10.2
Wat
er s
tora
ge a
nd tr
ansp
orta
tion
Wat
er s
tora
ge b
efor
e co
nsum
ptio
nO
pen-
top
cont
aine
rs
(buc
kets
)
Wat
er q
ualit
y de
teri
orat
e du
ring
st
orag
e
10.2
.1Ex
posu
re to
air
born
e su
bsta
nces
, suc
h as
dus
t, di
rt, f
lies
or o
ther
co
ntam
inan
ts
XX
XX
X
Con
tam
inat
ion
of w
ater
and
po
ssib
le s
prea
d of
dis
ease
sN
ot
rele
vant
Wat
er q
ualit
y de
teri
orat
e du
ring
st
orag
e
10.2
.2D
issi
patio
n of
chl
orin
e re
sidu
als
XX
Spre
ad o
f dis
ease
sN
ot
rele
vant
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Ope
n-to
p or
cl
osed
-top
cont
aine
rs
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Com
mun
al
stan
dpip
esU
nava
ilabi
lity
of
wat
er
A 10. Consumer
- 63 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Type
of h
azar
dous
ev.
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ard
Elem
ent
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
Wat
er q
ualit
y de
teri
orat
e du
ring
st
orag
e or
co
nsum
ptio
n
10.2
.3Po
or s
anita
tion
cond
ition
s by
con
sum
ers
XX
Con
tam
inat
ion
of w
ater
and
po
ssib
le s
prea
d of
dis
ease
sN
ot
rele
vant
Con
tam
inat
ion
at
colle
ctio
n ar
ea10
.2.4
Soile
d na
ppie
s or
soi
led
child
ren
was
hed
dire
ctly
at
the
grou
nd ta
nk
xx
Con
tam
inat
ion
of w
ater
and
po
ssib
le s
prea
d of
dis
ease
sN
ot
rele
vant
10.2
.5Po
or c
ondi
tion
and
age
of
the
cont
aine
rs, l
eaki
ng
cont
aine
rs
XX
X
XX
Una
vaila
bilit
y of
wat
er
and/
or c
onta
min
atio
n of
w
ater
Not
re
leva
nt
10.2
.6To
p no
t fitt
ed c
orre
ctly
ov
er th
e ta
nk a
llow
ing
dirt
an
d du
st to
ent
er th
e ta
nk
XX
XX
XC
onta
min
atio
n of
wat
er a
nd
poss
ible
spr
ead
of d
isea
ses
Not
re
leva
nt
10.2
.7Bi
ofilm
form
atio
n fr
om th
e in
ner w
alls
of t
he g
roun
d ta
nks
XX
XC
onta
min
atio
n of
wat
er a
nd
poss
ible
spr
ead
of d
isea
ses
Not
re
leva
nt
Gro
und
tank
s
Poor
wat
er q
ualit
y fr
om th
e co
ntai
ners
A 10. Consumer
- 64 -
11. O
rgan
izat
ion
Elab
orat
ed b
y: S
INTE
F
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
11.1
Org
aniz
atio
n11
.1.1
Use
of o
ut-o
f-dat
e gu
idel
ines
XX
XX
XX
X
11.1
.2In
appr
opri
ate
fina
ncia
l or
tech
nica
l co
nditi
ons
XX
XX
XX
XX
11.1
.3In
appr
opri
ate
pers
onal
or
gani
satio
n (e
.g. n
o as
sign
men
t of
resp
onsi
bilit
ies,
no
resp
onsi
ble
pers
on,
inap
prop
riat
e qu
alifi
catio
n)
XX
XX
XX
XX
11.1
.4In
suffi
cien
t on-
call-
duty
X
XX
XX
XX
X
11.1
.5In
suffi
cien
t and
/or
unqu
alifi
ed s
taff
(e.g
. ce
rtifi
ed, a
dequ
ate
labo
ur)
XX
XX
XX
XX
11.1
.6In
suffi
cien
t int
erna
l co
ordi
natio
n an
d sc
hedu
ling
XX
XX
XX
XX
11.1
.7O
pera
tiona
l fau
lt in
the
auto
mat
ised
pro
cess
due
to
o pr
ogra
mm
ing
by
unqu
alifi
ed s
taff
XX
XX
XX
X
Redu
ced
wat
er q
ualit
y,
redu
ced
avai
labi
lity,
dan
ger
to th
e st
aff o
r env
iron
men
t N
ot
rele
vant
Dis
turb
ance
of t
he
proc
ess
in g
ener
alO
rgan
izat
ion
Elem
ent
Type
of h
azar
dous
ev.
Type
of h
azar
dPo
tent
ial c
onse
quen
ces
Haz
ard
Refe
renc
eH
azar
dous
eve
nt
A 11. Organization
- 65 -
12. F
utur
e ha
zard
sEl
abor
ated
by:
Cha
lmer
s U
nive
rsity
of T
echn
olog
y
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
12.1
Sab
otag
e an
d te
rror
ist a
ttack
sTr
eatm
ent a
nd
dist
ribu
tion
12.1
.1Ph
ysic
al d
amag
e (e
.g.
bom
bing
atta
ck)
XX
XX
Wat
er s
hort
age
and
tech
nica
l dam
age
Not
re
leva
nt
Sour
ce w
ater
, tr
eatm
ent a
nd
dist
ribu
tion
12.1
.2In
tent
iona
l che
mic
al
cont
amin
atio
nX
X
Hea
lth e
ffect
s, w
ater
sh
orta
ge a
nd re
med
iatio
n of
su
pply
sys
tem
Not
re
leva
nt
Trea
tmen
t and
di
stri
butio
n (s
ourc
e w
ater
)
12.1
.3In
tent
iona
l mic
robi
al
cont
amin
atio
n
XX
Hea
lth e
ffect
s, w
ater
sh
orta
ge a
nd re
med
iatio
n of
su
pply
sys
tem
Not
re
leva
nt
Trea
tmen
t and
di
stri
butio
n12
.1.4
Cyb
er a
ttack
(e.g
. m
anip
ulat
ion
of
oper
atio
nal s
teps
)X
XX
XX
Hea
lth e
ffect
s an
d w
ater
sh
orta
geN
ot
rele
vant
Refe
renc
eH
azar
dous
eve
nt
Sabo
tage
and
te
rror
ist a
ttack
s
Elem
ent
Haz
ard
Pote
ntia
l con
sequ
ence
sTy
pe o
f haz
ardo
us e
v.Ty
pe o
f haz
ard
A 12. Future hazards (including the whole drinking water system)
- 66 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eH
azar
dous
eve
ntEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dous
ev.
Type
of h
azar
d
Sour
ce w
ater
, tr
eatm
ent a
nd
dist
ribu
tion
12.1
.5N
on a
cces
sibl
e in
form
atio
n. T
o pr
even
t sa
bota
ge a
nd te
rror
ist
atta
cks
info
rmat
ion
rega
rdin
g so
urce
wat
er,
trea
tmen
t and
dis
trib
utio
n ar
e cl
assi
fied.
Due
to th
is
all n
eces
sary
info
rmat
ion
mig
ht n
ot b
e av
aila
ble
to
the
pers
onal
and
peo
ple
in
gene
ral.
XX
XX
XX
X
If th
e pe
rson
al o
pera
ting
the
syst
em d
oes
not h
ave
all
nece
ssar
y in
form
atio
n ac
tions
mig
ht b
e ta
ken
that
in
trod
uce
new
risk
s to
the
syst
em. A
lso
peop
le in
ge
nera
l mig
ht, b
ecau
se o
f la
ck o
f inf
orm
atio
n, a
ct in
a
way
that
pos
e ne
w ri
sks
to
the
syst
em. W
ater
sho
rtag
e an
d he
alth
effe
cts
are
poss
ible
.
Not
re
leva
nt
Con
sum
ers
12.1
.6C
hang
ed h
uman
be
havi
our a
fter t
erro
rist
at
tack
s le
adin
g to
av
oida
nce
of ta
p w
ater
XX
XX
Indi
rect
dam
a ge.
Bec
ause
of
lack
of t
rust
in ta
p w
ater
pe
ople
use
wat
er fr
om o
ther
so
urce
s an
d if
this
wat
er is
of
poo
r qua
lity
it m
ight
ca
use
nega
tive
heal
th
effe
cts.
Not
re
leva
nt
12.2
Con
flic
tsSo
urce
wat
er,
trea
tmen
t and
di
stri
butio
n
12.2
.1M
ilita
ry c
onfli
cts
XX
XX
XX
X
Tech
nica
l dam
age,
wat
er
shor
tage
and
hea
lth e
ffect
sN
ot
rele
vant
Sour
ce w
ater
, tr
eatm
ent a
nd
dist
ribu
tion
12.2
.2Po
litic
al c
onfli
cts
XX
Polit
ical
act
ions
lead
ing
to
wat
er s
hort
age
Not
re
leva
nt
Sabo
tage
and
te
rror
ist a
ttack
s
Con
flict
s
A 12. Future hazards (including the whole drinking water system)
- 67 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eH
azar
dous
eve
ntEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dous
ev.
Type
of h
azar
d
Sour
ce w
ater
Con
flict
s12
.2.3
Com
petin
g la
ndus
eX
XX
XX
Wat
er s
hort
age,
co
ntam
inat
ed s
ourc
e w
ater
an
d he
alth
effe
cts
Not
re
leva
nt
12.3
New
che
mic
als
and
chan
ged
chem
ical
pat
hway
sSo
urce
wat
er12
.3.1
Dis
char
ge o
f new
ch
emic
als
to s
ourc
e w
ater
s du
e to
e.g
. acc
iden
ts o
r co
ntin
uous
leak
age
XX
Hea
lth e
ffect
s, w
ater
sh
orta
ge a
nd re
med
iatio
n of
su
pply
sys
tem
Not
re
leva
nt
Sour
ce w
ater
, tr
eatm
ent a
nd
dist
ribu
tion
12.3
.1D
isch
arge
of c
hem
ical
s du
e to
new
app
licat
ions
XX
Beca
use
know
n ch
emic
als
are
put i
nto
new
pat
hway
s th
ey m
ay c
ause
poo
r wat
er
qual
ity le
adin
g to
wat
er
shor
tage
, neg
ativ
e he
alth
ef
fect
and
rem
edia
tion
of
supp
ly s
yste
ms
Not
re
leva
nt
12.4
Em
ergi
ng p
atho
gene
sSo
urce
wat
er12
.4.1
Dis
char
ge to
sou
rce
wat
ers
XX
X
Hea
lth e
ffect
s, w
ater
sh
orta
ge a
nd re
med
iatio
n of
su
pply
sys
tem
Not
re
leva
nt
Con
sum
ers
12.4
.2C
han g
ed in
fect
ion
patte
rns
(incr
ease
d su
scep
tibili
ty to
in
fect
ions
am
ong
the
popu
latio
n)X
X
Hea
lth e
ffect
s an
d w
ater
sh
orta
geN
ot
rele
vant
Emer
ging
pat
hoge
ns
New
che
mic
als
and
chan
ged
chem
ical
pa
thw
ays
A 12. Future hazards (including the whole drinking water system)
- 68 -
DO
EO
SRe
f. O
S.Bi
olog
.C
hem
ic.
Rad. /
phys
.
Una
vai
lib.
Safe
tyEx
tern
al
dam
age
Des
crip
tion
To s
ub-
syst
em
Refe
renc
eH
azar
dous
eve
ntEl
emen
tH
azar
dPo
tent
ial c
onse
quen
ces
Type
of h
azar
dous
ev.
Type
of h
azar
d
12.5
Pub
lic c
once
rnC
onsu
mer
sPu
blic
con
cern
12.5
Repo
rts
on d
etec
tion
of
chem
ical
s or
pat
hoge
ns o
f ve
ry lo
w to
lera
bilit
yX
XA
nxity
and
dec
reas
ed tr
ust
in w
ater
sup
ply
Not
re
leva
nt
12.6
Clim
ate
chan
ges
Sour
ce w
ater
12.6
.1N
ew p
reci
pita
tion
and
evap
orat
ion
patte
rns
XX
Wat
er s
hort
age
Not
re
leva
ntSo
urce
wat
er12
.6.2
The
clim
ate
chan
ges'
effe
cts
on w
ater
qua
lity
(cha
nged
sur
face
runo
ff an
d m
ater
ial t
rans
port
ef
fect
ing
wat
er q
ualit
y)X
XX
X
Wat
er s
hort
a ge
and
poss
ible
he
alth
effe
cts
due
to p
oor
wat
er q
ualit
y, in
clud
ing
high
er te
mpe
ratu
re o
f su
pplie
d w
ater
Not
re
leva
nt
12.7
Agi
ng d
istr
ibut
ions
sys
tem
sD
istr
ibut
ion
12.7
.1D
amag
ed d
istr
ibut
ion
syst
em a
nd p
ossi
ble
intr
usio
n of
con
tam
inan
tsX
XX
XX
X
Wat
er s
hort
age,
hea
lth
effe
cts
and
tech
nica
l da
mag
e
Not
re
leva
nt
Dis
trib
utio
n12
.7.2
Incr
ease
d re
tent
ion
times
du
e to
ove
rsiz
ed s
yste
ms
XX
Wat
er q
ualit
y de
teri
orat
ion
due
to m
icro
bial
regr
owth
ca
usin
g he
alth
effe
cts
Not
re
leva
nt
Agi
ng d
istr
ibut
ion
syst
ems
Clim
ate
chan
ges
A 12. Future hazards (including the whole drinking water system)
- 69 -