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 -