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Appendix A

Extracts from the Gold Coast Water (GCW) Water Quality Management

System

In addition to the cases studies that have run alongside individual chapters this

appendix contains extracts from the Water Quality Management System!"CC# (!a$ard "nalysis Critical Control #oint) plan of Gold Coast Water

(GCW) adapted slightly to reflect the %ater safety plan terminology& GCW

operates several thousand 'ilometres of %ater mains %ith storage tan's and

t%o %ater treatment plants (Molendinar and Mudgeera*a) in "ustralia&

A1 INTRODUCTION

+he !"CC# plan (!a$ard "nalysis Critical Control #oint) from %hich thisexample %ater safety plan extract has *een derived is scoped to cover the entire

%ater system from catchment to tap and is a dynamic document continuallyevolving as increased 'no%ledge and experience present opportunities for

,-

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improvement& +here is very little detail on monitoring corrective actionreporting records and verification %ithin the *ody of the plan as such

information is contained in %ritten procedures %hich are referenced in the plan&In the day.to.day activities of operational staff the plan document has littlerelevance& +he operational procedures that implement the plan ho%ever are%ell.'no%n& Staff understand that product /uality failures are detected and

reported in this system& +hey also realise that adherence to procedures is adefence %hereas ignorance of procedure places individuals in a compromised

situation& "lmost all procedures received staff approval *efore *eing signed *ymanagement&

Management themselves are constantly presented %ith the opportunity to

interpret trends in operational failure reports and instigate planning or strategic

responses if necessary&

A2 TEAM

+o construct the initial system GCW gave the initiative formal pro0ect status and

allocated funding accordingly& 1ecause of the si$e of the system it %as

appropriate to have a dedicated %ater /uality officer to administer the pro0ect&

" team %as assem*led to o*tain the necessary detailed information a*out the%ater supply chain&

+eam expertise includes2

Quality systems 3 chemistry and *iology4

Water treatment 3 process design and control4

Senior %ater treatment plant operator4

Micro*iologist 3 %ith extensive %aterexperience4 Co.ordinator of catchmentmanagement4Water storage and distri*ution management4 Electronic control systems4

Senior 5anger (!in$e dam)4 and Customer liaison&

A3 WATER SUPPLY DESCRIPTION AND HAZARD

ANALYSIS

GCW strives to produce pota*le %ater that reaches its customers complying%ith those parameters of the "ustralian 6rin'ing Water Guidelines relevant to

the nature of its harvesting treatment and distri*ution operations&

,-7

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+he distri*ution for Gold Coast has *een divided into discrete reservoir $ones& +he $ones are delineated *y pressure differences or other supply

considerations& Each $one has a num*er of test points that are either reservoirsor sites unam*iguously lin'ed to reservoirs&

+he team leader in con0unction %ith the various team mem*ers identified all

the process steps involved in the harvesting treatment and distri*ution

activities& 8rom this identification process flo% diagrams %ere created (See "7

for examples of flo% charts of the Molendinar %ater purification plant and the

reticulation system) and then returned to appropriate staff for on.siteverification& +he next stage %as to conduct the ha$ard analysis& +his %as done

*y holding %or'shops and carrying out numerous on.site discussions %ithfacilitators and as many operational staff as practica*le& It %as valua*le to

engage a variety of operational staff as important additional 9fragments: of

'no%ledge %ere o*tained in this %ay&

A4 MONITORING, CONTROL AND CORRECTIVE

ACTION

Control measures %ere identified& 8or most control measures the matter of corrective action %as dealt %ith *y incorporating into monitoring and control

procedures& 8or other issues it %as more suita*le to state the corrective actionin the plan& 6evelopment of monitoring critical limits and corrective actions

%as achieved through a series of %or'shops meetings impromptu discussions(usually on.site) literature searches and experimentation&

A5 INCIDENT RESPONSEGCW uses an Incident Management #lan that descri*es ho% incidents and

emergency situations %ill *e managed& +his plan refers to the Incident

Management #rocedure& +he advantage of the Incident Management #rocedureis that it is activated *y certain critical limits (among other things) and that

corrective action is then specifically tailored to the conditions of the particular incident& 8or example %hen cyano*acteria levels in the storage exceed a critical

limit declaration of an incident is mandatory&

A6 VERIFICATION AND INTERNAL AUDIT

+he %ater /uality management system has *een designed to avoid reliance of 9end product testing: as system verification& +his has certainly *een the case

%ith respect to the %ater plants& End product testing ho%ever is re/uired *y,-;

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the guidelines and still has an important role to play in the verification of distri*ution system activities& +he plan treats each of the activities and process

steps as 9*arriers: to product degradation and each *arrier has a role to playstandards expected of it and specific mechanisms to achieve these standards&System verification has *een *uilt into 'ey procedures *y creating an audita*leaccounta*ility trial that encourages continuous improvement&

GCW has structured its internal audit system to have maximum effectiveness *y using trained internal auditors having no direct involvement %ith auditeesand *y rotating auditor tas's& "ppropriately /ualified persons carry out auditsre/uiring technical understanding& 8urther many 'ey operational proceduresare %ritten so as to prompt the internal auditors to matters re/uiring close

attention&

A7 SUPPORTING PROGRAMMES

Many ha$ards may *e related to the condition and suita*ility of e/uipment the

management of assets and the competency of staff& +hese are dealt %ith throughsupporting programmes& +hese include2

Service

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A8 FLOW DIAGRAMS

8igure ",2 Molendinar %ater purification plant 3 !"CC# process diagram

,,

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8igure ">2 5eticulation system 3 !"CC# process flo% diagram

A E!TRACTS FROM THE WATER "UALITY

MANAGEMENT PLAN

,>

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+a*le ",2 Catchments and dams

"ctivity or process

step

#otential ha$ards Control issues Critical limits Monitoring and?or control measures Corrective actions

W#$%& H#&'%($)*+ S$-+%

"griculture activities 8aecal contamination of

%ater%ays

Gra$ing activities Site specific limits

for colour tur*idity

*acteria p! salinity

and nutrients to *e

advised

5egular stream Monitoring *y Community

Services directorate of ,- catchment sites&

#rogram to *e revised and procedure for

critical limits and corrective action to *e

created&

5efer also to existing Catchment

Management #lan to control current

activity&

+o%n plan prohi*its further such

development in catchment&

6etection of significant pollutant levels

initiates investigation *y GCW staff&

Community a%areness and support

fostered&

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"ctivity or process

step


Chemical and micro*ial

pollution from

storm%ater poor

industrial practices and

spillages

#hysical pollution from

erosion and ru**ish

dumping

5ecreational activities Butrient release erosion

and ecological damage

Storm%ater control&

Industrial practices

eg& usage storage

and transport of fuels

and chemicals

6evelopment

activities eg&

1uilding road%or's

clearing tourism

expansion etc&

Control of fishing

camping picnics

social @ sporting

events horse riding

etc&

Bo control over run off or spillage from

existing activities&

5egular scientific tests are carried out on

catchment %aters&

+o%n plan re/uires run off control for future

approvals&

5angers inspect catchment areas and

maintain good a%areness of local activity&

(5angers reside in the catchment)&

Catchment 5ecreational Management #lan

and #rocedure M.=D.=- (5ecreation

Management)&

5egular scientific tests are carried out on

catchment %aters&

5efer procedure M.=D.=7 8ish release into

!in$e @

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"ctivity or process

step


Sa*otage Security 5egular 5anger patrols are carried out and

Batural Events 6am turnover Monitoring of

temperature stratum

Erosion

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"ctivity or process

step #otential ha$ards Control issues Critical limits Monitoring and?or control measures Corrective actions

Efficiency @ +elementry maintenance schedule carried #arts criticality analysis to *e

relia*ility of out *y perations @ Maintenance& Halves developed&

e/uipment #o%er

supply

can *e operated manually at inta'es& Mudgeera*a can s%itch to

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"ctivity or process

step


Compromising the health

of Consumers connected

to the ra% %ater pipelines

Maintenance @

repair of pipelines

from !in$e @

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+a*le ">2 Molendinar Water #lant

"ctivity or process

step

#otential ha$ards Control issues Critical or

operational limits

Monitoring and ?or con trol measures Correc tive act ions

5a% %ater

optimisation

Increased pro*a*ility of

micro*ial contamination

and process damage *y

dra%ing from lo% /uality

stratum&

ptimising dra% off

level

#resence of chlorine

resistant pathogens&

B" 5efer #rocedure M.=,.>== 5a% Water

ptimisationF(includes triggers for C@G

testing)

Wee'ly profiles and *acterial test are

performed&

5efer Catchment Management #lan for

identification and control of potential proto$oan

sources&

5efer #rocedure M.=,.>==

5a% Water ptimisationF

C ar*on dosing ffensive and tox ic

organics passing through

to treated %ater&

Suita*ility of car*on

type

Car*on currently in use is recommended *y

C5C tests&

#rocess "udit?5esearch section

monitor ne% products and

industry trends&

"vaila*ility and

/uality of car*on

supply

Efficiency and

relia*ility of process

@ e/uipment&

6osage

determination @

control

6osing limits are

event determined&

Supplier certified to IS;==> and ade/uate

supplies held&

Service agreement exists %ith @ M&

Maintenance schedule for facility exists& Anit

and process are functional *ut re/uire fre/uent

monitoring&

5efer #rocedures M.=,.>=,@> Car*on

6osing #rotocol @ #rocedureF

"lternative car*on suppliers are

availa*le&

5efer S

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"ctivity or process

step


operational limits


Staff 'no%ledge @

competence

Senior operator trains day la*our and verifies

dosing&

5etrain operators&

"fter hours control& 8ailure alarms on 'ey components lin'ed to

telemetry system& 6uty operator to respond&

1ac'up response *y >hr& Call

centre&

5ecycling of

*ac'%ash %ater

5eintroduction of

concentrated chemical @

micro*ial contaminants&

Effect on chemical

dosing strategy&

Control of

manganese levels&

Control of micro*ial

ha$ards

=&mg?< solu*le Mn

(operations limit)

==== cells?ml of

*lue green algaeF&

8aecal coliforms J

,== cfu per ,== ml

5efer #rocedure M.=,.>=7 Monitoring of

5ecycled 1ac'%ash WaterF& 1ac'%ash %ater is

,o

settled %ith solids to se%er&

5efer #rocedure M.=,.>=7 Monitoring of

5ecycled 1ac'%ash WaterF

5efer procedure M.=,.>=7

Monitoring of 5ecycled

1ac'%ash Water&

5efer procedure M.=,.>=7

Monitoring of 5ecycled

1ac'%ash Water&

C> dosing 6etention in concrete

lined mains causes

increases in p! %hich

reduces efficacy of

chlorine residual and

promotes precipitation

events&

Staff 'no%ledge @

competence

"vaila*ility and

/uality of C>

supply&

"vaila*ility @

/uality of C>

supply

5efer competency testing regime (Molendinar) 5etrain operators&

Supplier certified to IS ;=== series& "lternative supply uncertain *ut

plant can function %ithout C>

at the expense of *oosting

al'alinity&

Efficacy and

relia*ility of dosing

unit

"l'alinity of -.=

mg?<

,);

Maintenance @ peration of unit are the

responsi*ility of 1C gases&

5efer #rocedure M.=,.>=

(Car*on 6ioxide 6osing)

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"ctivity or process

step #otential ha$ards Control issues Critical or

operational limits

Monitoring and ?or con trol measures Correct ive act ions

6osage utside range for K 5efer #rocedure M.=,.>= 5efer #rocedure M.=,.>=

determination @ 7 hours L report

control

Staff 'no%ledge @ 5efer competency testi ng regi me (Molendinar) 5etr ain operators&

competence

Coagulation Anaccepta*le levels of Maintenance of Inspect daily& 5efer #rocedure M.=,.>,= 6aily #lant Contact @ M for reactive

flocculation @ settling physical chemical and mechanical and Inspection F& B o scheduled maintenance& repairs& S pare *utterfly valve

micro*ial impurities electrical system& can *e o*tained&

and?or toxins in treated

%ater&

Inlet flo% control Maintaining a Cali*rate monthly& 5efer to @ M Instrument Maintenance 5efer S

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"ctivity or process


operational limits


p! control of dosed #oor coagulation and Controlling p! in D& to (normal) 5efer #rocedure M.=,.>=; Molendinar 5efer #rocedure M.=,.>=;

%ater flocculation could lead to the flocculation .&- (Mn= dosing 6osed Water p! Molendinar 6osed Water p!F

pathogens *reaching the process& ranges in *rac'ets)

filter *arrier& &.D& (D&;) for .7

"esthetic colour hrsLreport

pro*lems could occur&& &.

D&(D&;K7hrsLshutd

o%n?report

.& for .7 hrsL

report

.& for K

7hrsLshutdo%n?repo

rt

J& for >hrs

Lshutdo%n?report

K& for > hoursL

shutdo%n ?report

"fter hours p! p! pro*e has high @ lo% alarms %ith varia*le "uto dialler calls programmed

control time responses& num*ers until human response

achieved&

#re

dosing is reduced and

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"ctivity or process

step


operational limits


#re lime is re/uired if

alum dosing is sufficient

to force ra% %ater p! too

lo%&

"vaila*ility @

/uality of lime

supply&

Supplier certified to IS ;=== series& "lternative suppliers availa*le&

Efficacy and


unit&

6osage

determination @

control&

5efer to @ M maintenance schedule

redundancy availa*le on dosing e/uipment&

Event determined 5efer #rocedure M.=,.>=- #re =-

#re =; (ph Control at Molendinar&

"lu m dosing 5efer dosed %ater p!

ha$ards&

"lum

"vaila*ility @

/uality of alum

supply&

Efficacy and


unit&

Supplier certified to IS ;=== series& "lternative supplier availa*le&

Maintenance schedule component redundancy& #rocedure M.=,.>= ("lum

6osing N Mol&)

,G>

"ccessi*ility to spares and tech& "dvice

#rocedure M.=,.>= ("lum 6osing N Mol&)

> hour service availa*le&

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"ctivity or process


operational limits


6osage +rue Colour J&= #rocedure M.=,.>= ("lum 6os ing N Mol&) Molendinar 6osed Water p!F

d et erminat ion @ C #A and M.=,.>=; Mole ndinar 6osed Water p!F #rocedu re M.= ,.>= (" lu m

control K for K> hours L 6osing N Mol&) and M.=,.>=;

report

K,= for K hrs L

shutdo%n?report

#olydadmac 6osing "t high flo%s dadmac #olydadmac

control is important for (Cationic #olymer)

optimal particle removal

(tur*idity)

"vaila*ility @ Q" supplier (alternate supplier avail&) "lternative supplier availa*le&

/uality of supply

Efficacy and Maintenance schedule component redundancy& > hour service availa*le&


unit&

6osage Event determined "ccessi*ilit y to spares @ tech& "dvice& 5efer procedure M.=,.>=D

determination @ 5efer procedure M.=,.>=D& (6osing of #olymer)

control&

Staff 'no%ledge @ 5efer #rocedure M.=,.>=D (Molendinar) 5etrain operators&

competence

,-

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"ctivity or process

step


operational limits


#ermanganate 6osing 8irst line response to

high manganese in ra%

%ater& 8ailure places

pressure on second

mechanism& 6irt y %ater

complaints increase if

Mn control fails&

#otassium

permanganate

(optional)

"vaila*ility @

Quality of Supply&

Q" supplier (alternate supplier avail&) "lternative supplier availa*le&

Efficacy and

relia*ility of 6osing

Anit

6osing protocol

determination @

control

+reated %ater

solu*le Mn levels of

J=&=> mg?l

Maintenance schedule component redundancy&

"ccessi*ility to spares and tech advice& 5efer

also #rocedure M.=,.>= (#ermanganate

6osing)&

#rocedure M.=,.>= (#ermanganate 6osing)

#re filter chlorination do%nstream removes

criticality of this process step&

> !our service availa*le&

#rocedure M.=,.>=

(#ermanganate 6sosing)

8ilter "id Small amounts used to

achieve high

performance in pea'

demand situations&

Staff 'no%ledge @

competence&

8ilter aid

"vaila*ility @

Quality of Supply

5efer competency testing regime (Molendinar) 5etraing operators&

IS ;=== certified supplier& "lternative supplier availa*le&

,

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"ctivity or process

step


operational limits


Efficiency and


Anit&

+emporary dosing unit in place due to main unit

failure&

Service contract %ith Oetflo&

6osage

determination @

control&

Staff 'no%ledge @

competence&

Solids Control Solids Control

Event determined #rocedure M.=,.>,> (Ase of 8ilter "id) #rocedure M.=,.>,> (use of

filter "id)

5efer competency testing regime (Molendinar) 5efrain operators&

Excessive solids *uild up

increases carryover and

effects filter

performance&

Effectiveness

relia*ility @

structural integrity

of ra'ing system&

Sludge *lan'et

control&

Clarifier ra'e systems are regularly maintained&

5efer procedure M.=,.,&

Clarifiers are operated to run %ith no sludge

*lan'et& Solids go to se%er& Clarifiers not used

%hen plant in Contact 8iltration mode&

5efer S

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"ctivity or process

step


operational limits


Efficacy and


Anit&

Maintenance schedule component redundancy

accessi*ility to spares @ tech& "dvice&

> hour Maintenance cover

availa*le& (refer S&

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"ctivity or process

step


operational limits


8lo% control&

#erformance

management?

analysis&

1ac'%ashing

procedure&

+ur*idity Control&

"fter hours tur*idity

control&

Mechanical and

electrical

maintenance of

*ac'%ashing

system&

8iltered %ater tur*&

f J=&> B+A

K=&> for > hrs L

report

K=&> for hrs L

shutdo%n

K=&- for > hrs L

shutdo%n

single filterK=&- for

>hrs L ta'e off line

"cid sol& "l J=&,

mg?,- 8iltration @ +ur*idity

Control at Molendinar

"ll filters have tur*idity meters %hich are

alarmed as is composite tur*idity meter&

5efer S

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"ctivity or process


operational limits


"ccidental or Bo toxic materials are stored near the clarifiers 5efer #rocedure M.=,.,=

deli*erate of filter cham*ers&

contamination of 8acility is loc'ed after hours %ith CC+H on the

filters& electronic gate entry& Standard perimeter *ar*

%ire fence in place& Malicious intent action is

not controlla*le as plant is mostly unmanned

%ithout movement sensors&

p! Correction Compromised "vaila*ility @ p! D&; 3 & Q" supplier (alternate supplier avail&) "lternative sources availa*le&

(lime or caustic) disinfection& 8ailure to /uality of supply& p! K & or JD&; for Investigate use of Megapac or

meet specification for hrs L report caustic&

Corrosive ?"l'aline K7& orJD for hrs

%ater& L shutdo%n @

report

Efficacy and Anit is effective& Contamination of the Clear

relia*ility of dosing Water +an'&

unit&

6osage 5efer M.=,.>, 6isinfection Control at 5efer M.=,.>, 6isinfection

determination @ Molendinar& Control at Molendinar&

control&

Staff 'no%ledge @ 5efer competency testing regime (Molendinar) 5efer +S +raining #lan&

competence&

,7

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"ctivity or process

step


operational limits


6isinfection

(Chlorination)

8ailure to eliminate

chlorine sensitive

pathogens&

+aste and odour

pro*lems&

+!M formation&

"vaila*ility @

/uality of Cl> supply

Efficacy and


unit& (Chlorine

delivery unit is not

flo% sensitive)&

6osage

determination @

control&

Cl> of ,.,&mg?l

%ith p! to &

Chlorine K,&

orJ,&=K7hrsLreport

K- or J=&> for , hr L

contact manager for

shutdo%n advice&

Q" supplier (alternate supplier avail&)

Maintenance schedule component redundancy

accessi*ility to spares @ tech& advice is

availa*le&

Wee'ly *acterial testing is carried out on ra% @

pota*le %ater & Emphasis placed on strict filter

tur*idity performance (continuous) and chlorine

control (continuous)

#rocedure M.=,.>, 6isinfection Control at

MolendinarF

"lternative sources availa*le&

> hour maintenance cover

availa*le& (refer S

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"ctivity or process

step


operational limits


no%ledge of and

competence in

manual plant

operation&

5efer procedure M.=,.-> Changing from

ent to ControlF&

5efer Competency testing

regime&

#o%er failure& A#S availa*le for computer system& 1ac'up diesel generator can

supply po%er to computer

system (A#S in place)

"fter hours failure& System has *ac' up hard drive and server& Change to manual control&

#rocedure included in section ",=

,D=

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+a*le "-2 Storage and reticulation system

"ctivity or #rocess

Step

#otential !a$ards Control Issues Cr it ical perati onal

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Critical perational Monitoring and?or Control Measures

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Ina*ility to control

pressure and flo% to

specification&

6istri*ution System

Monitoring

Monitoring and

maintenance of

devices to prevent

pressure extremes&

#late count J,==

cfu?ml&

+ur*idity J , n&t&u

+rue colour J

c&p&u&

8aecal?total coli:s

= c&f&u&?,== ml

5efer also

procedure 5S.=&

5efer #rocedure S6., 6istri*ution

"nalysis and InterpretationF and M.=.

=- 5eservoir Monitoring #rocedureF&

5efer to procedures M.=.>> >- > >7

%hich deal %ith testing maintenance and

repair of devices&

5efer #rocedures S6., 6istri*ution

"nalysis and InterpretationF M.=.

=- 5eservoir Monitoring #rocedureF

and M.=.= Bet%or'

Manipulation of +run' MainsF

5efer to procedures M.=.>> >-

> >7

#hysical

micro*ial

contamination

repairs

and

Wor'+echni/ues8lushtillClearF

Instruction

applies

line

%or'&

Internal

/uality

audits

of Civil

Wor's .

Water

procedu

res

carried

out in

situ

verify

flushingregime

is

adhered

to&

1acto

testing

has

verified

procedu

re is

effectiv

e&

5

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f

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t

o

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h

e

M

.

=

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instructions&

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Staff 'no%ledge and

competence

Be% 8ield Staff are placed %ith

experienced personnel for -.D months&

"ny changes in practices or e/uipment are

demonstrated to involve staff @

proceduralised&

"ll staff are su*0ect to periodical

performance appraisals& 8ield /uality

audits are carried out as part of IS

;===&

5esponse times 1rea'age

detailed

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l

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ions @ Maintenance

Be%

*tain

pressure certificates&

Be% mains

must pass *acterial @

pressure tests

*efore

connection to

the live system&

5efer to

StandardSpecifica

tions @

6ra%ing

s (Water)

,;;;

edition

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#hysical chemical @

micro*ial contamination

of pipelines due to

standpipe usage&

#revention of

*ac'flo% from

*usinesses into

mains&

8ailure of 8ire

fighting system

chec' valves&

Control of standpipe

distri*ution control

management and

monitoring of usage

practices&

Water supply la% re/uires that all

properties %ith ris' to %ater supply %ill

have *ac'flo% prevention&

%ners re/uired to comply %ith "S,7,

series re2 fire system maintenance&

B" #rocedure 5S.=, External Metered

StandpipesF & 8orms accompanying the

procedure descri*e terms @ conditions&

6esignated fill sites are inspected %ee'ly&

GCW has no control over these

devices& %ners are responsi*le for

maintenance&

GCW has no control over these

devices& %ners are responsi*le for

maintenance&

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f

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cu

l

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io

n

S

ys

t

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m

&

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Continuity of Supply 8ailure to supply& Control of 5eservoir

levels&

1rea'age response

times

5eservoir storage

capacity and trun'

delivery limitations

"lternative supply

methods

B" 5efer #rocedure M.=.=, peration of

Service res&F

#rioritising system in place (refer S

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5

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p

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M

.

=

.

=D

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n

leigh

5echlo

rinationF and

1ul'

Water

"gree

ment

%ith

1ris*a

ne

Wa

ter@

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5echlorination of 1ris*ane

Water

Micro*ial contamination

of product&

"vaila*ility @

/uality of Cl>

p! to 7

C,> =&> to ,&= mg?<

Quality assured supplier& 1ac' up supply

not critical& Scheduled maintenance *y

B&"&

5efer S

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Consumer 8eed*ac' 8ailure to recognise

consumer needs&

8ailure to recognise

system failures at an

early stage&

8ailure to consider

customer /uality

concerns in infrastructure

design&

8ailure to recognise poor

field %or'

6irty %ater calls&

+aste and odour

calls&

Illness complaints&

Miscellaneous %ater

/uality concerns

perational limits2

7 calls?> hours

7 calls?> hours

- calls?> hours

5efer procedure 5S.=7 #rocessing Water

Quality En/uiriesF

#rocedure included section ",=

&

,D7

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+a*le "2 Halidation of critical limits for Molendinar %ater treatment plant

Critical Control #oint Critical or perational

hrs& has *een effective in past incidents)

#rocedures +S.=,.>=>?- %ill allo% greater precision of future

dose determinations&

5ecycle of 1ac'%ash Water ====cell s?ml of

potentially toxic *lue green

algae&

8aecal coliforms of J,==

cfu?,==ml

1ased on P recycle volume and taste threshold of

== cells?ml *lue green algae

8aecal coliform limit *ased on ,7 months of data

and is designed to prompt investigation %hen

unusual rather than unsafe levels of faecals aredetected in the recycle stream&

5ecycle can constitute P of daily flo%& +he source of faecals

is the *ird population that fre/uents the clarifiers and thic'ener

tan's&

Coagulation flocculation @

settling

5a% %ater inlet flo%

,D;

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CommentsCri ti ca l Cont ro l #oint Crit ica l or pera tional Hal idat ion

,=)


settling"lum 6osing

+reated %ater true colour of

J c&p&u&

"6WG (,;;D) for +rue Colour "6WG specify J, c&p&u& ho%ever C&A& has *een

selected as a Critical limit for corrective action *ecause colour

a*ove is noticea*le in larger volumes and colour a*ove this

value %ould *e indicative of non optimal dosing that %ould

affect other %ater /uality parameters


settling p! Control of 6osed Water

,=

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CommentsCritical or perational

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settling

#re 8ilter Chlorination

+reated

Water

solu*le

Mn

levels of

J =&=>

mg?<

Experimental %or' carried out for

GCW *y Aniversity of Qld& In ,;7D

5eport entitled Investigation into

1iological Manganese xidation and

6eposition in the Gold Coast Water

6istri*ution System *y 6r& is

nominated as a trigger for corrective action&

5efer procedure +S.=,.>,- 8iltration @

+ur*idity at Molendinar&

,>

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HalidationCritical Control #oint CommentsCritical or perational

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A1. E!AMPLE PROCEDURES

OM/4./.3 R%(%&'-)& "0#)$ I*(%$)-* P&-%0&%

1 A)

+o provide instruction in carrying out Gold Coast Water:s reservoir monitoring programme&

2I*$&-0$)-*

Water leaving the Molendinar @ Mudgeera*a Water #urification #lants is

transported to approximately reservoirs around the city& Water is stored inthe reservoirs for varying amounts of time depending on demand& Storage

reservoirs must *e managed constructed and maintained to preserve productsafety and /uality at all times& In order to help achieve this goal the 5eservoir

Monitoring #rocedure has *een created&

3 P&-%0&%

3.1 Inspections

5eservoirs %ill *e inspected at least /uarterly to determine the safety @ integrity

of the structure& +he follo%ing tas's %ill *e performed2

"ny lea's corrosion and crac'ing %ill *e noted&

+he roof structure %ill *e inspected to ensure it has the condition to carry

out its function& +his %ill include the a*ility of the roof hatches and

any guttering to resist rain ingress&

Hents %ill *e examined to ensure they are a*le to prevent the entry of *irdsor rodents and allo% movement of air over the surface of the %ater&

+he reservoir site %ill *e assessed to ensure that the reservoir roof does notaccumulate excessive leaf litter&

+he reservoir and site should *e assessed to determine its a*ility to resistvandalism& +his %ill include a chec' of loc's on ladders anddetermining if children or vandals may gain access to the roof *y other

means such as trees or em*an'ments& 8encing and gates %ill also *echec'ed& Signs of human activity %ill *e noted&

,

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"t least every years every reservoir %ill undergo physical examination of its internal structure& +his %ill *e performed *y professional divers

(using dedicated pota*le e/uipment) and %ill involve the recording of structural condition safety access type of internal materials mixingcharacteristics sediment sampling and clean out (if re/uired)&

+he details of inspections %ill *e recorded in such a manner that the currentand historical data of each reservoir is availa*le&

3.2 Inspection assessments

Inspection findings %ill *e reported on forms M=.=-=, and =-=>&+hese

forms contain prompts and a condition rating system for reservoir components&

+he reports %ill *e for%arded to the Service 6elivery Section& Service 6elivery%ill determine the repair priorities for the various reservoirs *ased on cost and

safety ris's& 5epairs amounting to less than U,=== can *e organised *y @M

staff %ithout reference to Service 6elivery&

Service 6elivery %ill assess the ris's outlined in the inspection reports and if

necessary increase the fre/uency of inspection& 5eservoirs presenting seriousris' %ill *e *rought to the attention of the Manager Service 6elivery %ho has

the authority to approve necessary expenditure&

4 C&)$)# ))$( #* -&&%$)-* #$)-*

+he C5I+IC"<

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Service 6elivery %ill 'eep records of reservoir reports for at least years&Internal auditors of this procedure MAS+ select several reservoirs at random

and as' to see the inspection reports& +hey %ill then determine if the inspectionfre/uency is ade/uate and if re/uired %or' has *een carried out& Bon.

compliance %ith the procedure %ill *e noted in the audit report and a Corrective

"ction 5e/uest raised&

6 R%%&%*%(

M.=.=, peration of Service 5eservoirsM.=.=> 5eservoir CleaningM.=.,=7 @ ,=; "ccidental @ 6eli*erate Contamination of the 5eticulation SystemM.=.,,= 5eservoir?Water +o%er Ma0or Crac' or 8ailure&M.->.,,- +elemetry 8ailureS6., 6istri*ution "nalysis @ Interpretation&

,D

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OM/.1/213 F)$$)-* #* T0&))$ C-*$&- #$ M-%*)*#&

W#$%& T&%#$%*$ P#*$

1 A)

+o provide direction on optimal filtration management and tur*idity control atthe Molendinar Water #lant&

2 I*$&-0$-& )*-&#$)-*

It is the role of filtration to remove suspended materials from dosed %ater to a

degree that %ill permit effective disinfection& +o carry out the filtration processthe Molendinar plant has six dual media filters& +he top layer of filter mediaconsists of a*out =&7 metres of crushed (filter) coal and the *ottom layer consists of a*out =&, metres of sand a*ove =&>m of gravel %hich is graded in

si$e %ith the larger particles at the *ottom of the filter&+o put the capa*ility of the filtration process into perspective one must

consider that a typical *acterium has a si$e of a*out ,micron %hich is severalthousand times smaller than the average filter sand particle& Clearly this meansthat %ithout an effective coagulation and flocculation process filtration %ould

*e seriously limited in its a*ility to remove pathogens&8ilter performance is commonly measured in terms of tur*idity or particle

counts& +ur*idity is a reasona*ly sensitive measure of the amount of particulatematter in %ater and is measured *y tur*idimeters& +ur*idimeters ho%ever

cannot tell if the particles in %ater are gravel fragments *acteria algae or cryptosporidia& So to err on the side of safety an increase in tur*idity is #9#(

assumed to mean a decrease in the safety of the product& "n increase intur*idity of =&, to =&> can mean a ten.fold increase in particles& +herefore

%henever the tur*idity of filtered %ater increases at a plant it should initiate a

process of investigation *y operating staff&

3 M-*)$-&)*+ &-%0&%

Ander normal conditions the plant is capa*le of regularly producing filtered

%ater %ith a tur*idity of less than =&, B+A (according to the output from on

line tur*idity meters)& "s a matter of diligence therefore any deviation outsideof the normal operating values %ill *e treated as suspicious investigated and

rectified& It is not appropriate for operators to %ait until critical limits are

*reached *efore commencing investigative action&

,

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Each of the six filters at Molendinar is e/uipped %ith Great

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*ac'%ash se/uence or e/uipment& @ M should *e contacted if anye/uipment needs attention&

If the head loss trend has slo%ly increased since *ac'%ash and then appearsto level off and the filter displays a sudden rise in tur*idity this is a sign that

*rea'through is occurring& In this instance the filter must *e placed into manual *ac'%ash and su*se/uent performance closely monitored& If the filter repeats

the *rea'through *ehavior then the filter %ill *e ta'en off line and the individualsystem inspected&

If head loss of not excessive and the pattern is normal then the tur*idimeter

must *e suspected of malfunction& +he meter should *e inspected *led and

cleaned& +he last cali*ration record should *e examined and if necessary a ne%

cali*ration performed& " manual la*oratory test %ill *e performed for

comparison&

If the tur*idimeter is in order and head loss in normal then the flo% history(including A85H:s) of the filter should *e considered& Sudden changes in flo%%ill cause particle shear from filter media and this %ill of course increase

tur*idity& "lso clumping of filter media can contri*ute to *rea'through& In thefirst instance the history of the filter cell flo% meter should *e chec'ed as %ell

as the operation of the flo% control valve&

"s a last resort the filter should *e drained and the media inspected andcleaned if necessary& +he nature of the particles providing the tur*idity can *edetermined *y microscopic examination& +his tas' can *e carried out *y

Scientific Services&

3.1.2Collective Filter Failure

8rom time to time all tur*idimeters may indicate an up%ard trend from normal

operation& When this occurs the operator %ill carry out the follo%inginvestigation&

Chec' the p! of the dosed %ater on the SC"6" system and carry out a

manual chec' also& "*normal p! %ill indicate the dosing process has failed&

5efer procedure M.=,.>=; Molendinar 6osed Water p!F& In addition to thesteps indicated there a chec' of the polymer dosing and filter aid dosing

systems should *e made (if they are in use)& +he perator MAS+ verify thatdosing pumps in use are actually %or'ing and that the chemical is reaching it

intended destination&

If the dosing process appears to *e in order inspect the display panels on allthe tur*idimeters for any message that indicates malfunction&

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Chec' the ra% %ater (including the recycled *ac'%ash %ater) for changes in p! colour tur*idity suspended solids and manganese& Significant alteration on

the character of the ra% %ater %ill involve re.optimi$ation of the dosing regime perhaps involving 0ar tests&

Chec' the ra% %ater flo% meter& Since dosing of most chemicals is flo%

paced a significant drift in this meter can cause product deterioration& +he

meter should *e *led as a first chec' and cali*rated if necessary&

Chec' the /uality of the recycled %ater& 6eterioration in recycled %ater /uality can mean the dosing regime is inade/uate& Chec' also that sludgetransfer from the *ottom of the %ash %ater recovery tan's to se%er is occurringduring the settling phase&

Sudden flo% increases can cause shearing of de*ris from filter media& If this

is occurring the operator %ill reduce flo% to sta*ili$e *rea'through and then

slo%ly increase up to the desired level& It is prefera*le to choose lo%er outputof high /uality than higher output of compromised /uality&

Carry out a la*oratory p! and chlorine test on the filtered %ater if prechlorination is in use& Excessive dosing of chlorine can drive the p! do%n%ards

possi*ly affecting the coagulation process&

When plant tur*idity has increased *eyond normal operating levels and thecause is either not o*vious or %ill ta'e considera*le time to control then4

!E

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I the tur*idity of the filtered %ater "s per the on line instruments reaches anaverage of =&> B+A (for all filters) for more than hours the #

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reason to *elieve the ris' to pu*lic safety is or %ill soon *ecompromised& Incident teams %ill consist of various experts %ho %ill

determine a response suita*le for the features of the specific tur*idityfailure&

Shutting do%n the plant is an undesira*le option therefore as a last resort the6uty perator may consider trying *ringing tur*idity under control *y reducing

flo% from the filter?s& If this is successful in lo%ering the tur*idity thenshutdo%n may *e avoided (again provided the ris' level of the ra% %ater hasnot increased)& !o%ever it is o*vious that reduced flo% may lead to customer %ater shortages and still does not address the underlying cause of the initial

tur*idity incident&6uring a tur*idity incident the perator %ill also chec' the tur*idity of the

%ater leaving the reservoirs& +his %ater has a higher tur*idity than filtered%ater due to the formation of insolu*le inorganic material follo%ing post lime

p! correction& " typical figure is around =&- B+A (using la*oratory *ench top

unit) so it is possi*le a significant filter tur*idity failure %ill not *e easilydetected at this point& Bevertheless the tur*idity of this %ater should *e

recorded and reported&"s a matter of routine the Senior perator %ill revie% the >.hour tur*idity

trends each %ee'day and %ill ensure that any necessary excursions are %ritten(M.,,=,)& +he Coordinator of Water and Waste%ater %ill ma'e trend

inspections on a random *asis at least %ee'ly& Internal /uality auditors %ill alsoma'e a random chec' of tur*idity trends during internal /uality audits of this

procedure& "ny tur*idity excursions that have not *een properly reported %ill *e dra%n to the attention of the Manager perations @ Maintenance& +ur*idity

records for at least the previous ,> months %ill *e held&

4 R%-&$)*+ #* V%&))#$)-*

"ll !"CC# excursion reports (form ,,=,) %ill *e for%arded %ithin > hours

to2

6irector Gold Coast Water&

Manager perations @ Maintenance&

Manager Service 6elivery

Coordinator #roduct Quality

Coordinator Water @ Waste%ater

8ailing to report !"CC# excursions is a serious matter& perators %ho fail

to notify management of excursions are exposed to the possi*ility of personal,7>

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lia*ility in the event of pu*lic health conse/uences& nce excursions arereported it is the responsi*ility of the Management team to consider if the

excursion represents a need for a change in ris' management measures&+he !"CC# reporting system ensures that there is a paper trail for any event

exceeding Critical

w Sp 170805 Appa

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