EPA DriNkiNg WAtEr ADViCE NOtE Advice Note No. 8 ... Note No8.pdf · EPA DriNkiNg WAtEr ADViCE NOtE...

Advice Note No.8 | Version 1: Issued 02/08/2011 | Developing Drinking Water Safety Plans 1The Environmental Protection Agency

EPA DriNkiNg WAtEr ADViCE NOtEAdvice Note No. 8: Developing Drinking Water Safety Plans

2 EPA · Drinking ADViCE NOtE2 EPA · Drinking ADViCE NOtE

EPA DriNkiNg WAtEr ADViCE NOtEAdvice Note No. 8:

Developing Drinking Water Safety PlansVersion 1

Issued: 2 August 2011

Advice Note No.8 | Version 1: Issued 02/08/2011 | Developing Drinking Water Safety Plans 3

thE EPA has adopted the World health Organisation (WhO) water safety plan approach to ensuring drinking

water is both “safe” and “secure”. A supply is deemed ‘safe’ if it meets the relevant standards at the tap and

‘secure’ if a management system is in place that identifies all potential risks and procedures are in place to

manage these risks. the methodology described in this Advice Note ensures that a drinking water supply is safe

and secure through the use of a comprehensive risk assessment and risk management approach.

In 2009 the WHO published detailed guidance on the implementation of the Drinking Water Safety Plan

approach, the document is entitled Water Safety Plan Manual: Step-by-step risk management

for drinking water supplies and is available for download on the WHO website at

http://whqlibdoc.who.int/publications/2009/9789241562638_eng.pdf.

This Advice Note is intended to give an overview of the steps involved in constructing a water safety plan

and an outline of what it should contain in the Irish context. It contains guidance on hazard identification,

risk assessment and the preparation of action plans for hazards identified. This document is aimed at all

local authority staff involved in the production and distribution of drinking water and should be read in

conjunction with the WHO guidance manual when implementing a Drinking Water Safety Plan.

The Agency introduced the DWSP concept in 2009 by issuing a letter to all county managers outlining the

approach and advocating its use. The EPA Handbook published in 2010 also contains a section

(Section 10) covering DWSP’s. The approach applies equally to small and large drinking water supplies.

1IntroductIon

4 EPA · Drinking ADViCE NOtE

A DWSP is developed specifically for each water supply and should be considered as a risk management

strategy to ensure the continuous supply of safe water. The water safety plan approach builds on existing

good water supply management practices. An emphasis in the plan is placed on risk mitigation above

sampling, although targeted operational monitoring is still a key component of the plan.

The Key components of a DWSP are:

▼▼ an assessment of the water supply from source to tap to determine whether the water supply can

consistently deliver water of a quality that meets health-based targets. This assessment identifies the

potential hazards in each component of the water supply, the level of risk presented by each identified

hazard and the appropriate control measures for the identified risks to ensure that the water supply is

safe, the standards and targets are met, and human health is protected;

▼▼ operational monitoring of an appropriate nature and frequency at an appropriate point in the water

supply for each control measure identified and implemented from the supply assessment to ensure

that any deviation from the required performance is rapidly detected; and

▼▼ documentation of management arrangements including details of the supply assessment, validation

monitoring and operational monitoring. Documentation should also include a description of

the actions to be taken under normal operating and under incident conditions. During incident

conditions there is a risk of non-compliance with a standard (or target value) or failure to meet an

operational control, or there may be a potential risk to human health. These actions should include

appropriate investigations, remedial action in the form of improvement programmes, reporting and

communication.

It is important to differentiate clearly between the purpose of a DWSP and a Drinking Water Incident

Response Plan (DWIRP) though there is overlap between the two approaches. The DWIRP focuses

on actions to be taken following an unplanned event leading to the interruption of supply or the

contamination of a supply constituting a danger to public health. In comparison, the DWSP focuses on

actions to be taken to prevent an incident leading to a failure of the Drinking Water Regulations and/or a

potential danger to public health. A DWIRP is prepared at Water Services Authority level whereas a DWSP

is prepared at scheme/supply level. In some cases, if a control measure for a hazard identified under the

DWSP fails or if there is no control measure in place, then the hazard may have to be dealt with using the

DWIRP (e.g. a Cryptosporidium outbreak or flooding of the treatment plant). When preparing a DWSP

Water Service Authorities should integrate the DWIRP where relevant to avoid duplication or contradiction

between the two approaches.

The River Basin District Plans and the Water Management Units with their associated Action Plans should

be consulted and utilised for identification of hazards, assessment of risk and identification of control

measures in the catchment.

the WhO state that “the most effective means of consistently ensuring the safety of a drinking water supply is

through the use of a comprehensive risk assessment and risk management approach that encompasses all steps in

water supply from catchment to consumer”. this type of approach is called a Drinking Water Safety Plan (DWSP).

the basis of the approach is risk assessment but the primary objective is to protect human health.

2WhatIsadrInkIngWatersafetyPlan?


Assemble a team of experts

The first thing to do in preparing a DWSP is to assemble a team of people with a thorough knowledge

of each stage of the water supply. A team leader should be appointed, who as well as being a good

leader and communicator, should be of an appropriate level to communicate to senior management and

progress the work of the team. The team must have experience of the catchment and raw water sources,

water treatment processes, distribution networks, operations management, drinking water quality,

public health and domestic distribution systems. Most of the team will be drawn from within the Water

Services Authority but others such as catchment and public health specialists may be required from other

organisations.

In Ireland some or all of the catchment for supplies extend beyond the functional area of the Water

Services Authority. In this case, it will be necessary to have a representative from the other Water

Services Authority/Authorities either on the team or to serve as a contact during DWSP preparation and

implementation.

At all stages it is imperative that the DWSP team is supported by the Water Services Authority and is

given the necessary resources for the task.

Document and describe the supply

The next step is to document and describe the water supply and ensure that each element of the system

is captured. A description of the water supply is required to support the subsequent risk assessment

process. This step involves desk studies supported by site visits to confirm the knowledge, skills and

schematics available to the water supplier such as: the infrastructure at source, number and type of

sources, interconnectivity of sources, land use in the catchment, raw water storage, water treatment

including processes and chemicals used, treated water storage, secondary treatment (i.e. secondary

chlorination) and the distribution network. It is recommended that a simple flow diagram is prepared to

describe the supply. Examples of flow diagrams are given in Module 2 of the WHO guidance manual.

identify the hazards and hazardous events

This stage involves an assessment of what could go wrong at each step of the drinking water supply

process as described in the flow diagram. Site visits as well as desk studies are required at this stage.

Hazard identification also requires assessment of historic information and events as well as predictive

information based on knowledge of the treatment and supply systems. Risks that are not readily obvious

should also be considered such as the siting of the treatment works in a flood plain (where there is no

record of flooding), the age of pipes or the presence of lead pipe work in the distribution system.

Appendix 1 of this document provides assistance to water suppliers in completing this step by providing a

list of typical hazardous events associated with each element of the supply. It must be noted that the list

is not exhaustive and additional hazards can be added by the water supplier where they are specific to a

supply. Similarly, not every hazard on the list will apply to each water supply.

It is important to note that stakeholder involvement is important at this stage as the DWSP is not just

about the water supplier, many other bodies can be involved and should be involved to ensure the

success of the approach, such as: agriculture, forestry, industry, residents groups, consumers, regulators

and other Water Services Authorities.

3guIdanceonthePreParatIonofWatersafetyPlan

3.1

3.2

3.3


Perform a risk Assessment

When each hazardous event is identified, an assessment is carried out to assess the level of risk posed by

each hazard. The initial risk assessment assesses the risk posed by the hazard in isolation of any existing

control measures that are in place. This is the worst case scenario, and can often be difficult to visualise

due to our knowledge of the control measures downstream of the hazard.

Risk assessment is a consideration of both the likelihood of a hazard occurring, and the impact or severity

should it occur. A semi-quantitative approach is recommended comprising informed estimations of

likelihood and severity.

A risk matrix is provided in Appendix 2. Likelihood and severity are scored on a scale of 1 to 5, a set of

descriptors is provided to help with scoring (Tables 1 and 2). The values for likelihood and severity are

multiplied together to give a value for the risk posed, resulting in a maximum risk score of 25.

The risk scores are classified as follows:

▼▼ 1 to 5 – Low risk,

▼▼ 6 to 10 – Medium risk,

▼▼ 12 to 15 – High risk,

▼▼ 16 to 25 – Very High risk.

Define and Validate Control measures

Anything that reduces the risk posed is termed a control measure (also known as a mitigation measure or

barrier), such as treatment stages, monitors and alarms, operator knowledge, training etc. Most hazards

can be mitigated by control measures to reduce the risk, however this is not always the case particularly

in the catchment. In this situation, the next stage (i.e. treatment) will act as mitigation and so on.

Many control measures will already be in place, although some will not have been tested. The next

stage is to validate the control measures in place. Validation should not be confused with operational

monitoring which verifies that the control measure is working and shows when there is an abnormal

situation. For many controls, validation involves concentrated monitoring to test the control measure.

For systems including filtration, validation could be carried out using daily turbidity monitoring, e.g. if the

turbidity goes no higher than a pre-determined level, say 0.2 NTU, in at least 95% of the daily samples

taken in a month. Validation of controls may also involve imitating a hazard e.g. an alternative power

source may be validated by simulating a power outage and assessing if the backup power source is

sufficient to run the required processes.

reassess risk to determine current risk

The second stage of risk assessment takes into account the effectiveness of the control measures currently

in place, and assesses the level of risk remaining. The same procedure is used as described above for the

initial risk assessment (Appendix 2) in order to determine the current or residual risk.

At the initial and current risk assessment stages the team should record the reasoning behind the

decisions made by the team for future reference.

The outcome of the current risk classification determines the action to be taken for the hazard (Table 4).

If there is no control in place, the action should be applied after the initial risk assessment.

3.4

3.5

3.6


Establish improvement/action plan for risks

Following the initial and current risk assessment a risk classification for each hazard is required before and

after mitigation. This may highlight deficiencies in the current control measure or the fact that a control

measure is absent (e.g. absence of a Cryptosporidium barrier or inadequate fencing at the intake) and

thus requiring action. An action plan is prepared for every hazard classified as medium risk or higher.

A template action plan is provided in Appendix 3. The template details the initial risk assessment, control

measures (both those validated and already in place and controls planned in the short-term) and the

current risk classification for each hazard. The level of detail on each sheet will vary depending on the

hazards but for those hazards that remain high or very high despite mitigation, a detailed action plan is

required with target dates for completion of the planned actions. In this case the action plan should

also be signed off at Director of Services level or by another suitably qualified person in the Water

Services Authority.

In cases where there are plans in place by the Water Services Authority to provide additional mitigation

in the future (may be dependent on funding in the longer term), the expected benefit of the proposed

measures can be included in the Action Plan as a ‘Target’ risk assessment, indicating the eventual risk

rating.

It is suggested that each risk in the hazard spreadsheet is linked (by hyperlink) to its corresponding Action

Plan worksheet.

Define Monitoring of the Control Measures and Verify effectiveness of the DWSP

Operational monitoring should be defined for the supply (frequency of monitoring, who carries out

monitoring, where monitoring takes place, who receives and assesses the results etc.). The level of

monitoring will vary depending on the control measure in place. Operational monitoring can be

measurable (chlorine residuals, turbidity) or observable (integrity of fencing, locks on reservoir covers).

Critical control measures will normally be measured online. For some control measures it may be

necessary to define ‘critical limits’ outside of which the safety of the water supply is diminished. Plant

operators need to be aware when a system is operating under normal conditions and when there is an

incident.

The DWSP needs to be verified to ensure that it is working properly, verification involves three activities:

▼▼ Compliance monitoring, to ensure the results are consistent with water quality targets;

▼▼ Internal and external audits to ensure water quality risks are controlled, and;

▼▼ Verification of consumer satisfaction.

Management procedures and Documenting

All aspects of the DWSP should be clearly documented (description of supply, hazard list, risk assessment,

level of monitoring etc.) and the documentation should be available for review by the supervisory

authority. Management procedures are the actions to be taken during normal operational conditions

(as verified by operational monitoring) and the corrective actions to be taken during an incident. Near

misses should also be recorded for future reference. It should be noted that there may be some overlap

with DWIRP procedures in relation to some incident situations and recording of same.

3.7

3.8

3.9


Supporting programmes – develop skills & knowledge

Supporting programmes enable commitment to the DWSP approach and provide the capacity to deliver

safe water. They include staff training, provision of equipment (for monitoring or calibration), preventative

maintenance, hygiene and sanitation. Existing support programmes may need to be reviewed and

updated.

regular review of hazards, risks, controls (e.g. new equipment)

The DWSP is a working document and forms an integral part of operational practices. A schedule for

periodic full reviews of the DWSP should be defined but it should also be reviewed after any significant

event e.g. an exceedance notified to the EPA, an incident, installation of new key piece of equipment,

staff changes etc.

3.10

3.11


aPPendIx1hazardIdentIfIcatIonsheets

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

001

Floo

ding

lead

ing

to r

apid

cha

nges

and

var

iabi

lity

in w

ater

qua

lity/

no b

alan

cing

tan

k fo

r ra

w w

ater

002

Abs

ence

of

char

acte

risat

ion

of t

he r

aw w

ater

sou

rce

003

Pres

ence

of

Cry

ptos

porid

ium

in t

he r

aw w

ater

004

Urb

an w

aste

wat

er –

dis

char

ge w

ith p

oten

tial t

o ca

use

mic

robi

al c

onta

min

atio

n

005

Urb

an w

aste

wat

er –

dis

char

ge o

f su

bsta

nces

tha

t ar

e an

imm

inen

t da

nger

to

publ

ic h

ealth

006

Urb

an w

aste

wat

er –

dis

char

ge f

rom

sto

rm w

ater

ove

rflo

w w

ith p

oten

tial t

o ca

use

mic

robi

al

cont

amin

atio

n

007

Drin

king

wat

er –

tre

atm

ent

plan

t di

scha

rgin

g sl

udge

s up

stre

am o

f in

take

008

Fore

stry

– f

ellin

g ca

usin

g in

crea

sed

sedi

men

tatio

n of

the

raw

wat

er

009

Aqu

acul

ture

(fr

eshw

ater

) –

caus

ing

cont

amin

atio

n (f

eed,

pes

ticid

es e

tc.)

010

Run

off

from

con

stru

ctio

n/de

velo

pmen

t ac

tiviti

es u

pstr

eam

of

inta

ke c

ausi

ng c

onta

min

atio

n |

(oil

spill

s, s

ilt, c

emen

t, b

ento

nite

s, s

oaka

way

s, o

pen

tank

s, s

urfa

ce w

ater

ince

ptor

s)

011

Qua

rrie

s –

sedi

men

tatio

n or

nitr

ate

risk

from

exp

losi

ves

used

012

Hyd

ro p

ower

gen

erat

ion

stat

ions

– c

hang

es in

raw

wat

er q

ualit

y du

e to

hyd

ro g

ener

atio

n

013

Wild

life

– or

gani

c an

d m

icro

bial

con

tam

inat

ion

014

Recr

eatio

nal u

se o

f so

urce

wat

er c

ausi

ng m

icro

bial

con

tam

inat

ion

or o

il sp

ills

015

Alg

al b

loom

s/eu

trop

hica

tion

in la

ke s

ourc

e

016

Stra

tific

atio

n in

lake

sou

rce

017

Risk

of

oil s

pill

ente

ring

the

supp

ly (

e.g.

gen

erat

ors,

hou

seho

ld h

eatin

g oi

l, fa

rm f

uel,

ESB

tran

sfor

mer

s, r

oad

traf

fic a

ccid

ent

etc.

)

018

Dre

dgin

g/ar

teria

l dra

inag

e w

orks

/flo

od p

rote

ctio

n w

orks

cau

sing

incr

ease

d se

dim

enta

tion

upst

ream

019

Any

oth

er u

rban

run

-off

tab

le 1

. S

OU

rC

E –

Ca

tch

me

nt

of

Su

rfa

ce W

ate

r S

up

ply


tab

le 2

. S

OU

rC

E –

Ca

tch

me

nt

of

gro

un

d W

ate

r S

up

ply

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

020

Doe

s th

e vu

lner

abili

ty c

ateg

ory

(incl

udin

g ka

rst

feat

ures

and

rec

harg

e) in

dica

te t

hat

grou

ndw

ater

may

bec

ome

cont

amin

ated

by

surf

ace

or s

hallo

w d

isch

arge

s?

021

Doe

s th

e A

quife

r C

lass

ifica

tion

indi

cate

a f

ast

time

of t

rave

l and

hen

ce p

ose

a ha

zard

to

drin

king

wat

er q

ualit

y?

022

Is t

he w

ell h

ead

com

plet

ion

desi

gned

and

con

stru

cted

in a

man

ner

that

will

exc

lude

sur

face

w

ater

or

spill

ages

of

cont

amin

ated

mat

eria

l cau

sing

mic

robi

al o

r ot

her

cont

amin

atio

n?

023

Is t

he w

ell h

ead

secu

red

agai

nst

lives

tock

acc

ess

caus

ing

mic

robi

al c

onta

min

atio

n?

024

Doe

s th

e bo

reho

le h

ave

a pu

mp

cham

ber

casi

ng,

the

annu

lus

of w

hich

has

bee

n fu

lly g

rout

ed

(line

d) b

y in

ject

ion

from

the

bas

e of

the

cas

ing

to t

he g

roun

d su

rfac

e to

pre

vent

intr

usio

n of

su

rfac

e w

ater

or

othe

r co

ntam

inat

ion?

025

Is t

he in

filtr

atio

n ga

llery

influ

ence

d by

sur

face

wat

er c

ausi

ng m

icro

bial

con

tam

inat

ion?

026

Are

the

re la

nd d

rain

s ca

usin

g pr

efer

entia

l pat

hway

for

pol

lutio

n of

sha

llow

wel

l sou

rce?


tab

le 3

a.

SO

Ur

CE

– C

atc

hm

en

t o

f S

urf

ace

Wa

ter

or

gro

un

dw

ate

r S

up

ply

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

027

Effe

ct o

f cl

imat

e ch

ance

on

sour

ce w

ater

028

On-

site

was

te w

ater

tre

atm

ent

syst

ems/

sept

ic t

anks

with

pot

entia

l to

caus

e m

icro

bial

con

tam

inat

ion

029

Goo

d A

gric

ultu

ral P

ract

ice

for

the

Prot

ectio

n of

Wat

ers

Regu

latio

ns (

S.I.

No.

101

of

2009

) no

t co

mpl

ied

with

030

Agr

icul

ture

– m

icro

bial

con

tam

inat

ion

(fro

m a

nim

al a

cces

s, la

nd s

prea

ding

or

stor

age

of s

lurr

y or

dun

g)

031

Agr

icul

ture

– c

onta

min

atio

n fr

om d

ange

rous

sub

stan

ces

(e.g

. sh

eep

dipp

ing

chem

ical

s/pe

stic

ides

)

032

Agr

icul

ture

– c

onta

min

atio

n fr

om n

itrat

es/p

hosp

hate

s

033

Aba

ttoi

rs –

org

anic

and

mic

robi

al c

onta

min

atio

n

034

Fore

stry

– c

hem

ical

or

orga

nic

fert

ilisa

tion

caus

ing

high

nitr

ates

035

Fore

stry

– p

estic

ides

036

Fore

stry

– P

AH

's (

fires

)

037

Fore

stry

– f

ellin

g ca

usin

g in

crea

sed

sedi

men

tatio

n of

the

raw

wat

er

038

Indu

stry

, lic

ense

d or

unl

icen

sed

(incl

udin

g IP

PC/S

ectio

n 4)

– c

hem

ical

con

tam

inat

ion

039

Indu

stry

, lic

ense

d or

unl

icen

sed

(incl

udin

g IP

PC/S

ectio

n 4)

– m

icro

bial

con

tam

inat

ion


tab

le 3

b.

SO

Ur

CE

– C

atc

hm

en

t o

f S

urf

ace

Wa

ter

or

gro

un

dw

ate

r S

up

ply

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

040

Indu

stry

, lic

ense

d or

unl

icen

sed

(incl

udin

g IP

PC/S

ectio

n4)

– lo

ss o

f so

urce

wat

er d

ue t

o co

ntam

inat

ion

041

Min

ing

– ch

emic

al o

r m

etal

con

tam

inat

ion

042

Tran

spor

t –

road

run

off

(pe

stic

ides

, ch

emic

als)

043

Tran

spor

t –

railw

ay r

un o

ff (

pest

icid

es)

044

Tran

spor

t –

airp

ort

run

off

(org

anic

che

mic

als)

045

Geo

logy

– a

rsen

ic,

lead

, flu

orid

e, u

rani

um,

rado

n or

oth

er p

oten

tially

har

mfu

l nat

ural

su

bsta

nce

in r

aw w

ater

046

Con

tam

inat

ed la

nd u

pstr

eam

of

inta

ke c

ausi

ng c

onta

min

atio

n

047

Land

fill l

each

ate

ente

ring

wat

er

048

Redu

ced

suff

icie

ncy

of s

uppl

y du

e to

com

petin

g w

ater

use

rs/o

ver

abst

ract

ion

of s

ourc

e/dr

ough

t co

nditi

ons

049

Vand

alis

m –

del

iber

ate

cont

amin

atio

n of

sou

rce

and

unau

thor

ised

acc

ess

050

Nuc

lear

dis

aste

r

051

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

the

cat

chm

ent


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

052

Inta

ke n

ot s

ecur

ed a

gain

st li

vest

ock

acce

ss c

ausi

ng m

icro

bial

con

tam

inat

ion

053

Lake

sou

rce

inta

ke p

oint

vul

nera

ble

to v

aria

tion

due

to s

trea

ms/

str

atifi

catio

n/al

gal b

loom

s/in

crea

sed

turb

idity

054

Scre

ens

– no

scr

eeni

ng in

pla

ce f

or r

aw w

ater

055

Scre

ens

– bl

ocki

ng o

r br

eakd

own

of m

echa

nica

l scr

eens

056

Sedi

men

t bu

ild u

p at

inta

ke c

ham

ber

caus

ing

cont

amin

atio

n

057

Risk

of

inva

sive

spe

cies

clo

ggin

g up

the

inta

ke (

e.g.

pon

d w

eed

or z

ebra

mus

sel)

058

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

the

raw

wat

er in

take

tab

le 4

. S

OU

rC

E –

ra

w W

ate

r in

tak

e

tab

le 5

. S

OU

rC

E –

ra

w W

ate

r S

tora

ge

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

059

Susc

eptib

le t

o al

gal b

loom

s ca

usin

g ta

ste/

odou

r is

sues

060

Susc

eptib

le t

o bu

ild u

p of

tox

ins

061

Susc

eptib

le t

o st

ratif

icat

ion

062

Subj

ect

to s

urfa

ce w

ater

influ

ence

, flo

odin

g or

oth

er m

icro

bial

con

tam

inat

ion

(e.g

. wild

life

acce

ss)

063

Vand

alis

m –

del

iber

ate

cont

amin

atio

n of

sou

rce

and

unau

thor

ised

acc

ess

064

Slud

ge b

uild

up

in r

aw w

ater

tan

k ca

usin

g co

ntam

inat

ion

065

Leak

ing

impo

undi

ng r

eser

voir

caus

ing

ingr

ess

of c

onta

min

atio

n

066

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

raw

wat

er s

tora

ge


tab

le 6

. S

OU

rC

E –

ra

w W

ate

r Li

ne

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

067

Pipe

cor

rode

d or

not

wat

ertig

ht c

ausi

ng in

gres

s of

sur

face

wat

er

068

Raw

wat

er s

ervi

ng c

onsu

mer

s w

ithou

t di

sinf

ectio

n or

oth

er t

reat

men

t

069

Pipe

com

posi

tion

caus

ing

cont

amin

atio

n (e

.g.

pres

ence

of

lead

pip

e w

ork)

070

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

the

raw

wat

er li

ne

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

101

Surf

ace

wat

er s

uppl

y w

ith n

o C

rypt

ospo

ridiu

m b

arrie

r in

pla

ce

102

Gro

undw

ater

or

sprin

g su

pply

, in

fluen

ced

by s

urfa

ce w

ater

with

no

Cry

ptos

porid

ium

bar

rier

in

plac

e

103

Trea

tmen

t pl

ant

oper

atin

g ab

ove

desi

gn c

apac

ity

104

By-p

assi

ng o

f an

y st

age

of t

reat

men

t

105

Freq

uent

and

sig

nific

ant

flow

var

iatio

ns t

hrou

gh t

he w

orks

106

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

pla

nt d

esig

n

tab

le 7

. t

rE

At

ME

Nt

PLA

Nt

– P

lan

t D

esi

gn


tab

le 8

. t

rE

At

ME

Nt

PLA

Nt

– C

oa

gu

lati

on

/Flo

ccu

lati

on

/Cla

rifi

cati

on

Sta

ge

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

107

Floc

car

ry o

ver

due

to in

appr

opria

te/in

adeq

uate

dos

ing

regi

me

108

Floc

car

ry o

ver

due

to o

verlo

adin

g of

the

pla

nt/s

urge

flo

ws

109

Floc

car

ry o

ver

due

to p

oor

adju

stm

ent/

mai

nten

ance

/des

ign

of la

mel

la p

late

s

110

Floc

car

ry o

ver

due

to p

oor

mai

nten

ance

or

flood

ing

of s

ettle

men

t ch

anne

ls

111

Floc

car

ry o

ver

due

to v

aria

tions

in r

aw w

ater

cha

ract

eris

tics

112

Floc

car

ry o

ver

due

to e

ffec

ts o

f w

eath

er c

ondi

tions

113

Floc

car

ry o

ver

due

to in

adeq

uate

cle

anin

g re

gim

e fo

r cl

arifi

ers

114

Floc

car

ryov

er d

ue t

o po

or s

ettle

men

t/un

stab

le s

ludg

e bl

anke

t

115

Floc

car

ryov

er d

ue t

o sl

udge

flo

at/s

crap

er n

ot o

pera

ting

prop

erly

116

Floc

car

ryov

er d

ue t

o sl

udge

con

cent

rato

rs n

ot o

pera

ting

prop

erly

117

Floc

car

ryov

er d

ue t

o sl

udge

ble

eds

not

oper

atin

g pr

oper

ly

118

Floc

car

ryov

er d

ue t

o in

suff

icie

nt s

ludg

e dr

aw o

ff

119

Inad

equa

te c

lean

ing

regi

me

in c

hem

ical

mix

ing/

cont

act

tank

120

Alg

al o

r pl

ant

grow

th in

cla

rifie

rs c

ausi

ng p

oor

wat

er q

ualit

y an

d cl

ogge

d fil

ters

121

Poor

str

uctu

ral i

nteg

rity

of c

larif

iers

cau

sing

con

tam

inat

ion

due

to in

gres

s

122

Slud

ge r

ecyc

led

to h

ead

of w

orks

123

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

Coa

gula

tion/

Floc

cula

tion/

Cla

rific

atio

n


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

124

Inad

equa

te p

re-t

reat

men

t (i.

e. n

o cl

arifi

catio

n st

age)

125

Inad

equa

te p

roce

ss c

ontr

ol in

pla

ce f

or f

iltra

tion

(e.g

. la

ck o

f tu

rbid

ity m

onito

rs)

126

Inad

equa

te p

artic

le r

emov

al d

ue t

o ov

erlo

adin

g of

the

filt

ers

127

Inad

equa

te p

artic

le r

emov

al d

ue t

o bl

ocke

d fil

ters

128

Inad

equa

te p

artic

le r

emov

al d

ue t

o in

adeq

uate

filt

er m

edia

dep

th

129

Inad

equa

te p

artic

le r

emov

al d

ue t

o in

adeq

uate

filt

er m

edia

com

posi

tion

130

Inad

equa

te p

artic

le r

emov

al d

ue t

o in

adeq

uate

bac

kwas

hing

reg

ime

(e.g

. in

adeq

uate

cyc

le

leng

th,

unev

en s

cour

, pu

mp

failu

re,

loss

of

filte

r m

edia

)

131

Inad

equa

te p

artic

le r

emov

al d

ue t

o po

or f

ilter

mai

nten

ance

(cr

acks

, bo

ils e

tc)

132

Filte

red

wat

er f

rom

rap

id g

ravi

ty f

ilter

s pu

t ba

ck in

to s

uppl

y w

ithou

t sl

ow s

tart

/run

ning

to

was

te

133

Filte

red

wat

er f

rom

slo

w s

and

filte

rs p

ut b

ack

into

sup

ply

with

out

adeq

uate

rip

enin

g pe

riod

134

Filte

red

Wat

er –

ris

k of

Cry

ptos

porid

ium

bre

akth

roug

h

135

Filte

red

Wat

er –

tur

bidi

ty b

reak

thro

ugh

grea

ter

than

0.2

NTU

in s

ites

whe

re t

here

is a

ris

k of

th

e pr

esen

ce o

f C

rypt

ospo

ridiu

m in

the

raw

wat

er (

as p

er G

uida

nce

in E

PA H

andb

ook)

136

Back

was

h w

ater

rec

ycle

d to

hea

d of

wor

ks c

ausi

ng in

crea

sed

turb

idity

137

Alg

al g

row

th in

filt

ers

caus

ing

poor

par

ticle

rem

oval

138

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

filt

ratio

n

tab

le 9

. t

rE

At

ME

Nt

PLA

Nt

– F

iltr

ati

on


tab

le 1

0.

tr

EA

tM

EN

t P

LAN

t –

Me

mb

ran

e F

iltr

ati

on

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

139

Mem

bran

e fil

trat

ion

– fo

ulin

g ca

usin

g bl

ocka

ge a

nd b

ypas

s of

filt

ers

140

Mem

bran

e fil

trat

ion

– br

each

cau

sing

byp

ass

of f

ilter

s

141

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

mem

bran

e fil

trat

ion

tab

le 1

1.

tr

EA

tM

EN

t P

LAN

t –

Dis

infe

ctio

n

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

142

Lack

of

duty

/sta

ndby

arr

ange

men

ts f

or d

isin

fect

ion

equi

pmen

t (e

.g.

chlo

rine,

UV

) in

the

eve

nt

of f

ailu

re o

r du

ring

mai

nten

ance

. Fo

r sm

all s

uppl

ies

trea

ted

with

UV,

the

abi

lity

to s

hut

off

the

supp

ly in

the

eve

nt o

f a

failu

re o

r du

ring

mai

nten

ance

is a

ccep

tabl

e if

no u

ndis

infe

cted

wat

er

can

ente

r th

e m

ains

143

Lack

of

auto

mat

ic s

witc

hove

r ar

rang

emen

ts f

or d

isin

fect

ion

equi

pmen

t (c

hlor

ine

dosi

ng,

UV

) in

th

e ev

ent

of f

ailu

re o

r du

ring

mai

nten

ance

144

Lack

of

onlin

e m

onito

r fo

r ke

y di

sinf

ectio

n eq

uipm

ent

145

Lack

of

dial

out

ala

rm in

the

eve

nt o

f a

failu

re o

f ke

y di

sinf

ectio

n eq

uipm

ent

146

Inad

equa

te c

onta

ct t

ime

in p

lace

in a

ccor

danc

e w

ith W

HO

req

uire

men

ts

147

Chl

orin

e do

sing

is n

ot f

low

pro

port

iona

l

148

Lack

of

appr

opria

te v

alid

atio

n ce

rtifi

cate

for

UV

tre

atm

ent

syst

em

149

Lack

of

UV

I or

UV

T m

onito

r (t

o ve

rify

UV

is o

pera

ting

with

in it

s va

lidat

ed r

ange

at

all t

imes

)

150

UV

sys

tem

ope

ratin

g ou

tsid

e its

val

idat

ed r

ange

151

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

dis

infe

ctio

n


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

152

Any

oth

er h

azar

d no

t co

ntro

lled

in t

he c

atch

men

t

153

Con

tam

inat

ion

with

una

ppro

ved

trea

tmen

t ch

emic

als/

mat

eria

ls

154

Che

mic

als

used

aft

er e

xpira

tion

date

– in

effe

ctiv

e ch

emic

als

155

Che

mic

als

deliv

ered

to

inco

rrec

t st

orag

e ve

ssel

156

Che

mic

al in

ject

ion

poin

t(s)

vul

nera

ble

to p

oten

tial d

amag

e

157

Loss

of

pow

er s

uppl

y/no

bac

kup

or a

ltern

ativ

e po

wer

sup

ply

158

Elec

tric

al s

urge

cau

sing

loss

of

com

mun

icat

ion

and

reco

rds

159

Elec

tric

al e

quip

men

t an

d pu

mps

tha

t co

uld

cont

ain

PCBs

(la

rge

tran

sfor

mer

s, p

ower

cor

rect

ion

units

and

oil

fille

d ci

rcui

t br

eake

rs)

160

Vand

alis

m –

cau

sing

loss

of

supp

ly o

r de

liber

ate

cont

amin

atio

n at

tre

atm

ent

plan

t

161

Inst

rum

enta

tion

failu

re –

loss

of

cont

rol e

.g.

set

poin

ts f

or t

urbi

dity

mon

itors

162

Tele

met

ry –

com

mun

icat

ion

failu

re

163

Floo

ding

– lo

ss o

r re

stric

tion

of t

reat

men

t w

orks

164

Loss

or

rest

rictio

n of

acc

ess

to t

he p

lant

due

to

wea

ther

ext

rem

es o

r ot

her

even

t

165

Adv

erse

wea

ther

con

ditio

ns a

ffec

ting

trea

tmen

t ch

emic

als

and/

or p

roce

sses

tab

le 1

2a

. t

rE

At

ME

Nt

PLA

Nt

– O

the

r


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

166

Fire

/exp

losi

on –

loss

or

rest

rictio

n of

tre

atm

ent

wor

ks

167

Spill

fro

m u

nbun

ded

chem

ical

or

oil s

tora

ge t

ank

caus

ing

cont

amin

atio

n

168

Fuel

spi

ll du

e to

anc

illar

y w

orks

at

the

plan

t fr

om e

quip

men

t su

ch a

s ge

nera

tors

, co

n-sa

ws

etc.

169

Use

of

flow

met

ers

cont

aini

ng m

ercu

ry

170

Che

mic

al o

verd

ose

due

to p

oor

proc

ess

cont

rol

171

Ava

ilabi

lity

and

cont

inui

ty o

f su

pply

of

trea

tmen

t ch

emic

als

– in

adeq

uate

sto

rage

of

chem

ical

st

ocks

, ris

k of

run

ning

out

of

key

trea

tmen

t ch

emic

als

172

Ava

ilabi

lity

and

cont

inui

ty o

f su

pply

of

spar

e pa

rts

for

key

wat

er t

reat

men

t eq

uipm

ent

e.g.

UV

bul

bs

173

Crit

ical

pum

p fa

ilure

lead

ing

to lo

ss o

f su

pply

174

Risk

of

fluor

ine

over

dose

in t

reat

ed w

ater

175

Poor

qua

lity

batc

h of

che

mic

als

(e.g

. lo

w c

once

ntra

tion)

del

iver

ed o

r m

ade

up o

n-si

te le

adin

g to

inad

equa

te t

reat

men

t

176

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

tre

atm

ent

tab

le 1

2b

. t

rE

At

ME

Nt

PLA

Nt

– O

the

r


tab

le 1

3a

. D

iSt

riB

Ut

iON

– D

istr

ibu

tio

n N

etw

ork

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

201

Any

haz

ard

not

cont

rolle

d/m

itiga

ted

by t

he t

reat

men

t pl

ant

202

Pres

ence

of

disi

nfec

tion

by-p

rodu

cts

in t

he n

etw

ork

(e.g

. TH

M's

)

203

Insu

ffic

ient

dis

infe

ctio

n in

dis

trib

utio

n ne

twor

k ca

usin

g m

icro

bial

rec

onta

min

atio

n

204

Proc

edur

e fo

r di

sinf

ectio

n of

wat

er m

ains

fol

low

ing

repa

ir an

d m

aint

enan

ce n

ot in

pla

ce

caus

ing

mic

robi

al c

onta

min

atio

n

205

Mai

ns b

urst

cau

sing

ingr

ess

of c

onta

min

atio

n

206

Ingr

ess

of c

onta

min

ated

wat

er c

ause

d by

low

pre

ssur

e or

pre

ssur

e w

aves

207

Unm

aint

aine

d pi

pe n

etw

ork

caus

ing

ingr

ess

of c

onta

min

atio

n

208

Leak

age/

bloc

ked

pipe

s/m

alfu

nctio

ning

pum

ps a

nd v

alve

s ca

usin

g in

gres

s of

con

tam

inat

ion

209

Inte

rmitt

ent

supp

ly c

ausi

ng in

gres

s of

con

tam

inat

ion

210

Ope

ning

/clo

sing

val

ves

caus

ing

reve

rsed

flo

w a

nd d

istu

rbin

g de

posi

ts

211

Ope

ning

/clo

sing

val

ves

caus

ing

intr

oduc

tion

of s

tale

wat

er

212

Scou

ring

oper

atio

ns c

ausi

ng d

istu

rbed

dep

osits

213

Use

of

unap

prov

ed m

ater

ials

cau

sing

con

tam

inat

ion

of w

ater

sup

ply


tab

le 1

3b

. D

iSt

riB

Ut

iON

– D

istr

ibu

tio

n N

etw

ork

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

214

Third

par

ty a

cces

s to

hyd

rant

s ca

usin

g co

ntam

inat

ion

due

to b

ackf

low

215

Third

par

ty a

cces

s to

hyd

rant

s ca

usin

g in

crea

sed

flow

dis

turb

ing

depo

sits

216

Back

flow

fro

m in

dust

rial p

rem

ises

, dom

estic

pre

mis

es, u

naut

horis

ed c

onne

ctio

ns o

r un

regu

late

d su

pplie

s w

ithou

t ad

equa

te b

ackf

low

pre

vent

ion

devi

ces

caus

ing

cont

amin

atio

n of

the

pub

lic w

ater

su

pply

217

Pres

ence

of

lead

mai

ns in

the

ow

ners

hip

of t

he C

ounc

il

218

Pres

ence

of

lead

com

mun

icat

ion

pipe

s in

the

ow

ners

hip

of t

he C

ounc

il

219

Leac

hing

and

pip

e w

ork

corr

osio

n le

adin

g to

ent

ry o

f co

rros

ion

by-p

rodu

cts

into

wat

er s

uppl

y (e

.g.

lead

, co

pper

. et

c)

220

Con

tam

inat

ed la

nd o

r oi

l or

solv

ent

spill

age

caus

ing

cont

amin

atio

n th

roug

h pe

rmea

ble

plas

tic

(uPV

C o

r po

lyet

hyle

ne)

pipe

wor

k

221

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

the

dis

trib

utio

n ne

twor

k


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

222

Ope

n re

serv

oir

caus

ing

reco

ntam

inat

ion

by w

ildlif

e et

c.

223

Leak

ing

Rese

rvoi

r ca

usin

g in

gres

s of

con

tam

inat

ion

224

Unp

rote

cted

acc

ess

cove

rs a

nd/o

r ve

nts

caus

ing

cont

amin

atio

n

225

Vand

alis

m –

del

iber

ate

cont

amin

atio

n of

tre

ated

wat

er a

nd u

naut

horis

ed a

cces

s

226

Lack

of

mai

nten

ance

and

cle

anin

g of

res

ervo

irs c

ausi

ng c

onta

min

atio

n (s

ludg

e bu

ild-u

p in

re

serv

oirs

, pr

esen

ce o

f de

ad v

erm

in,

etc)

227

Leve

l sen

sor

failu

re in

res

ervo

ir ca

usin

g re

serv

oir

to r

un lo

w r

esul

ting

in p

oor

wat

er q

ualit

y or

ou

tage

228

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

res

ervo

irs a

nd w

ater

tow

ers

tab

le 1

4.

DiS

tr

iBU

tiO

N –

Se

rvic

e r

ese

rvo

irs

& W

ate

r to

we

rs

tab

le 1

5.

CO

NS

UM

Er

Pr

EM

ES

iS

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

301

Any

haz

ard

not

cont

rolle

d/m

itiga

ted

with

in t

he d

istr

ibut

ion

netw

ork

302

Lack

of

cont

inge

ncy

plan

s in

pla

ce t

o ai

d vu

lner

able

cus

tom

ers

303

Lead

pip

e w

ork

in t

he o

wne

rshi

p of

the

con

sum

er c

ausi

ng le

ad c

onta

min

atio

n

304

Hig

h co

lour

/tur

bidi

ty/ir

on le

vels

at

cons

umer

s ta

p

305

Una

ppro

ved

taps

and

plu

mbi

ng e

quip

men

t in

the

ow

ners

hip

of t

he c

onsu

mer

cau

sing

co

ntam

inat

ion

306

Any

add

ition

al s

ite-s

peci

fic h

azar

d(s)

ass

ocia

ted

with

con

sum

er p

rem

ises


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

401

Supp

ly is

hig

h ris

k or

ver

y hi

gh r

isk

in C

rypt

ospo

ridiu

m R

isk

Ass

essm

ent

402

App

ropr

iate

Cry

ptos

porid

ium

mon

itorin

g pr

ogra

mm

e no

t in

pla

ce

403

Lack

of

onlin

e m

onito

rs a

nd a

larm

s cr

itica

l to

plan

t m

anag

emen

t (e

.g.

turb

idity

, ch

lorin

e,

amm

onia

, pH

)

404

Com

plia

nce

mon

itorin

g no

t ca

rrie

d ou

t in

acc

orda

nce

with

DW

Reg

ulat

ions

405

Ope

ratio

nal m

onito

ring

not

carr

ied

out

as n

eces

sary

406

Any

add

ition

al s

ite s

peci

fic h

azar

d(s)

ass

ocia

ted

with

mon

itorin

g

tab

le 1

6.

MA

NA

gE

ME

Nt

& C

ON

tr

OL

– M

on

ito

rin

g

tab

le 1

7a

. M

AN

Ag

EM

EN

t &

CO

Nt

rO

L –

Ma

na

ge

me

nt

ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

407

Lack

of

a do

cum

ente

d M

anag

emen

t Sy

stem

in p

lace

408

Stan

dard

ope

ratin

g pr

oced

ures

not

in p

lace

or

not

docu

men

ted

409

Proc

edur

e fo

r de

alin

g w

ith n

on-c

ompl

ianc

es w

ith T

able

A,

B an

d C

par

amet

ers

and

notif

icat

ion

to E

PA/H

SE n

ot in

pla

ce

410

Hyg

iene

pro

cedu

res

not

in p

lace

or

plan

t op

erat

or m

anag

es w

aste

wat

er a

nd d

rinki

ng w

ater

tr

eatm

ent

plan

ts c

ausi

ng r

isk

of c

ross

con

tam

inat

ion

411

Lack

of

reco

rd k

eepi

ng f

or c

ritic

al c

ontr

ols

412

Lack

of

daily

che

cks

on k

ey e

quip

men

t

413

Inad

equa

te c

aret

akin

g co

ver

(incl

udin

g sh

ift)

at t

he p

lant


ris

k N

o.

haz

ard

Des

crip

tio

nin

itia

l ris

k r

anki

ng

(s

ee w

ork

shee

t)

Val

idat

ion

of

Co

ntr

ol M

easu

res

(in

clu

de

dat

e va

lidat

ion

to

ok

pla

ce)

rev

ised

ris

k r

anki

ng

(s

ee w

ork

shee

t)

Dat

e o

f r

evis

ed

ris

k A

sses

smen

t (t

o p

rovi

de

a ti

me

line

on

up

gra

des

an

d im

pro

vem

ents

)

414

Inad

equa

te c

all-o

ut f

acili

ties

in p

lace

for

car

etak

ers,

rel

ief

care

take

rs,

tech

nici

ans,

ele

ctric

ians

, pl

umbe

rs e

tc

415

Car

etak

er o

r re

lief

care

take

r no

t ad

equa

tely

tra

ined

in r

espe

ct o

f hi

s/he

r du

ties

416

Car

etak

er h

as n

ot c

ompl

eted

the

WST

G 5

day

drin

king

wat

er (

FETA

C L

evel

5)

cour

se

417

Syst

em f

or r

epor

ting

inci

dent

s or

exc

eeda

nces

to

man

agem

ent

not

in p

lace

418

Syst

em f

or f

ollo

w u

p of

EPA

Aud

its,

Dire

ctio

ns o

r ot

her

reco

mm

enda

tions

not

in p

lace

419

Drin

king

Wat

er In

cide

nt R

espo

nse

Plan

not

in p

lace

420

Syst

em o

f in

tern

al a

udit

not

in p

lace

421

Proc

edur

e fo

r re

spon

ding

to

alar

ms

not

in p

lace

or

not

oper

atio

nal d

ue t

o H

R is

sues

422

Com

plet

e In

form

atio

n Sy

stem

sho

win

g th

e di

strib

utio

n ne

twor

k et

c. n

ot u

p to

dat

e

423

Cal

ibra

tion

sche

dule

s no

t in

pla

ce f

or k

ey d

osin

g an

d m

onito

ring

equi

pmen

t in

clud

ing

mon

itors

and

ala

rms

424

Mai

nten

ance

sch

edul

e/co

ntra

ct n

ot in

pla

ce f

or k

ey t

reat

men

t an

d m

onito

ring

equi

pmen

t in

clud

ing

mon

itors

and

ala

rms

425

Cus

tom

er c

ompl

aint

pro

toco

l not

in p

lace

426

Syst

em f

or a

n an

nual

rev

iew

of

DW

SP n

ot in

pla

ce

427

Impr

ovem

ent

prog

ram

me

for

supp

ly o

n th

e RA

L no

t in

pla

ce

428

Syst

em f

or f

eedb

ack

of m

onito

ring

resu

lts (

sour

ce a

nd t

reat

ed w

ater

) to

pla

nt o

pera

tors

not

in

plac

e

429

Poor

hou

seke

epin

g ca

usin

g co

ntam

inat

ion

(bird

s, f

lies

in t

he t

reat

men

t pl

ant)

430

Any

add

ition

al s

ite s

peci

fic h

azar

d(s)

ass

ocia

ted

with

man

agem

ent

tab

le 1

7b

. M

AN

Ag

EM

EN

t &

CO

Nt

rO

L –

Ma

na

ge

me

nt


Level Descriptor Description

1 Most unlikely Has not happened in the past and is highly improbable that it will happen in the future

2 Unlikely Has happened in the past, is possible and cannot be ruled out completely

3 Foreseeable Has happened in the past, is possible and under certain circumstances could happen again

4 Likely Has occurred in the past more than once, is likely to happen again

5 Almost certain Has occurred in the past, is an ongoing problem, and is very likely to happen again

table 1. Likelihood Descriptors

aPPendIx2descrIPtors,rIskassessmentmatrIxandactIonmatrIx

Level Descriptor Description(s)

1 Insignificant Wholesome water, no public health impact

2 Minor Short term or localised, aesthetic or not health related. Treatment compromised. No regulatory failure

3 Moderate Long term non-compliance, widespread aesthetic issues or not health related. Treatment compromised. Regulatory failure but no health risk

4 Major Potential long term health effects (e.g. lead, THM’s, nitrate). Treatment compromised. Regulatory failure. Disruption to consumers in the supply

5 Catastrophic Presence of micro-organisms, parasites or substances that are an imminent danger to public health (e.g. E.coli, Cryptosporidium). Treatment compromised. Regulatory failure. Disruption to consumers in the supply

table 2. Severity/impact of Consequence Descriptors


Severity/impact of Consequence

Insignificant Minor Moderate Major Catastrophic

1 2 3 4 5

Almost certain 5 5 (L) 10 (M) 15 (H) 20 (VH) 25 (VH)

Likely 4 4 (L) 8 (M) 12 (H) 16 (VH) 20 (VH)

Foreseeable 3 3 (L) 6 (M) 9 (M) 12 (H) 15 (H)

Unlikely 2 2 (L) 4 (L) 6 (M) 8 (M) 10 (M)

Most unlikely 1 1 (L) 2 (L) 3 (L) 4 (L) 5 (L)

table 3. risk Assessment MatrixLi

kelih

oo

d

Low 1 – 5, Medium 6 – 10, High 12 – 15, Very High 16 – 25

risk Classification

Action

Low Manage using routine procedures, keep under review

Medium Action required, plan and prepare

High Priority action required to mitigate hazard in short term

Very High Urgent action required to prevent hazard (e.g. shut down supply/ boil notice or water restriction), action required to mitigate hazard in short term

table 4. Action to be taken following risk assessment


table 1. risk Assessment Action Plan

aPPendIx3actIonPlantemPlate

riSk ASSESSMENt – Action Plan revision: A Date:

hazard As per hazard sheet

hazard ref Number As per hazard sheet

Scope of hazard A brief explanation of the hazard

responsibility for putting controls in place

Overall: e.g. Director of Service/ Senior Engineer

Local: e.g. Senior Executive Engineer/Executive/Plant Manager

Estimated Liklihood & Severity

Likelihood: Rating: with brief explanation of reason for the decision

Severity: Rating: with brief explanation of reason for the decision

initial risk Assessment (Refer to Risk Assessment Matrix)

e.g Very High

Calculation of risk rating

Likelihood Category 4

Severity category 4

Risk Rating 16

Control/ Mitigation Measures Briefly describe the control measures in place. If no control measures are in place, outline the planned control measures with dates. If risk is High or Very High despite mitigation provide an action plan with target dates including long term mitigation measures

1. 2. 3. 4. 5. 6.

Target Completion

Date

Actual Completion

Date

Action by: Validated Yes/No

Validation of Control MeasuresInclude brief comment on the validation method for each control measures

1. 2. 3. 4. 5. 6.

Current risk Assessment(Refer to Risk Assessment Matrix)

Risk assessment with existing controls in place

e.g Very High



Severity category 3

Risk Rating 12

Sign off Name: For High and V High risks, the Director of Service or a suitably qualified person must sign-off

Position:

target risk Assessment (Refer to Risk Assessment Matrix)

Risk assessment when future planned controls are in place

e.g Low



Severity category 1

Risk Rating 4

rA Completed by: Name: DWSP team member as defined in DWSP

Position:

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