w sp 170805 appa
TRANSCRIPT
-
8/17/2019 w Sp 170805 Appa
1/51
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
,-
-
8/17/2019 w Sp 170805 Appa
2/51
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
-
8/17/2019 w Sp 170805 Appa
3/51
+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,-;
-
8/17/2019 w Sp 170805 Appa
4/51
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$ards may *e related to the condition and suita*ility of e/uipment the
management of assets and the competency of staff& +hese are dealt %ith throughsupporting programmes& +hese include2
Service
-
8/17/2019 w Sp 170805 Appa
5/51
A8 FLOW DIAGRAMS
8igure ",2 Molendinar %ater purification plant 3 !"CC# process diagram
,,
-
8/17/2019 w Sp 170805 Appa
6/51
8igure ">2 5eticulation system 3 !"CC# process flo% diagram
A E!TRACTS FROM THE WATER "UALITY
MANAGEMENT PLAN
,>
-
8/17/2019 w Sp 170805 Appa
7/51
+a*le ",2 Catchments and dams
"ctivity or process
step
#otential ha$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&
-
8/17/2019 w Sp 170805 Appa
8/51
"ctivity or process
step
#otential ha$ards Control issues Critical limits Monitoring and?or control measures Corrective actions
Chemical and micro*ial
pollution from
storm%ater poor
industrial practices and
spillages
#hysical pollution from
erosion and ru**ish
dumping
5ecreational activities Butrient release erosion
and ecological damage
Storm%ater control&
Industrial practices
eg& usage storage
and transport of fuels
and chemicals
6evelopment
activities eg&
1uilding road%or's
clearing tourism
expansion etc&
Control of fishing
camping picnics
social @ sporting
events horse riding
etc&
Bo control over run off or spillage from
existing activities&
5egular scientific tests are carried out on
catchment %aters&
+o%n plan re/uires run off control for future
approvals&
5angers inspect catchment areas and
maintain good a%areness of local activity&
(5angers reside in the catchment)&
Catchment 5ecreational Management #lan
and #rocedure M.=D.=- (5ecreation
Management)&
5egular scientific tests are carried out on
catchment %aters&
5efer procedure M.=D.=7 8ish release into
!in$e @
-
8/17/2019 w Sp 170805 Appa
9/51
"ctivity or process
step
#otential ha$ards Control issues Critical limits Monitoring and?or control measures Corrective actions
Sa*otage Security 5egular 5anger patrols are carried out and
Batural Events 6am turnover Monitoring of
temperature stratum
Erosion
-
8/17/2019 w Sp 170805 Appa
10/51
"ctivity or process
step #otential ha$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
-
8/17/2019 w Sp 170805 Appa
11/51
"ctivity or process
step
#otential ha$ards Control issues Critical limits Monitoring and?or control measures Corrective actions
Compromising the health
of Consumers connected
to the ra% %ater pipelines
Maintenance @
repair of pipelines
from !in$e @
-
8/17/2019 w Sp 170805 Appa
12/51
+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
-
8/17/2019 w Sp 170805 Appa
13/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
Staff 'no%ledge @
competence
Senior operator trains day la*our and verifies
dosing&
5etrain operators&
"fter hours control& 8ailure alarms on 'ey components lin'ed to
telemetry system& 6uty operator to respond&
1ac'up response *y >hr& Call
centre&
5ecycling of
*ac'%ash %ater
5eintroduction of
concentrated chemical @
micro*ial contaminants&
Effect on chemical
dosing strategy&
Control of
manganese levels&
Control of micro*ial
ha$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)
-
8/17/2019 w Sp 170805 Appa
14/51
"ctivity or process
step #otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correct ive act ions
6osage utside range for K 5efer #rocedure M.=,.>= 5efer #rocedure M.=,.>=
determination @ 7 hours L report
control
Staff 'no%ledge @ 5efer competency testi ng regi me (Molendinar) 5etr ain operators&
competence
Coagulation Anaccepta*le levels of Maintenance of Inspect daily& 5efer #rocedure M.=,.>,= 6aily #lant Contact @ M for reactive
flocculation @ settling physical chemical and mechanical and Inspection F& B o scheduled maintenance& repairs& S pare *utterfly valve
micro*ial impurities electrical system& can *e o*tained&
and?or toxins in treated
%ater&
Inlet flo% control Maintaining a Cali*rate monthly& 5efer to @ M Instrument Maintenance 5efer S
-
8/17/2019 w Sp 170805 Appa
15/51
"ctivity or process
step #otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correct ive act ions
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
-
8/17/2019 w Sp 170805 Appa
16/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
#re lime is re/uired if
alum dosing is sufficient
to force ra% %ater p! too
lo%&
"vaila*ility @
/uality of lime
supply&
Supplier certified to IS ;=== series& "lternative suppliers availa*le&
Efficacy and
relia*ility of dosing
unit&
6osage
determination @
control&
5efer to @ M maintenance schedule
redundancy availa*le on dosing e/uipment&
Event determined 5efer #rocedure M.=,.>=- #re =-
#re =; (ph Control at Molendinar&
"lu m dosing 5efer dosed %ater p!
ha$ards&
"lum
"vaila*ility @
/uality of alum
supply&
Efficacy and
relia*ility of dosing
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&
-
8/17/2019 w Sp 170805 Appa
17/51
"ctivity or process
step #otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correct ive act ions
6osage +rue Colour J&= #rocedure M.=,.>= ("lum 6os ing N Mol&) Molendinar 6osed Water p!F
d et erminat ion @ C #A and M.=,.>=; Mole ndinar 6osed Water p!F #rocedu re M.= ,.>= (" lu m
control K for K> hours L 6osing N Mol&) and M.=,.>=;
report
K,= for K hrs L
shutdo%n?report
#olydadmac 6osing "t high flo%s dadmac #olydadmac
control is important for (Cationic #olymer)
optimal particle removal
(tur*idity)
"vaila*ility @ Q" supplier (alternate supplier avail&) "lternative supplier availa*le&
/uality of supply
Efficacy and Maintenance schedule component redundancy& > hour service availa*le&
relia*ility of dosing
unit&
6osage Event determined "ccessi*ilit y to spares @ tech& "dvice& 5efer procedure M.=,.>=D
determination @ 5efer procedure M.=,.>=D& (6osing of #olymer)
control&
Staff 'no%ledge @ 5efer #rocedure M.=,.>=D (Molendinar) 5etrain operators&
competence
,-
-
8/17/2019 w Sp 170805 Appa
18/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
#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&
,
-
8/17/2019 w Sp 170805 Appa
19/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
Efficiency and
relia*ility of 6osing
Anit&
+emporary dosing unit in place due to main unit
failure&
Service contract %ith Oetflo&
6osage
determination @
control&
Staff 'no%ledge @
competence&
Solids Control Solids Control
Event determined #rocedure M.=,.>,> (Ase of 8ilter "id) #rocedure M.=,.>,> (use of
filter "id)
5efer competency testing regime (Molendinar) 5efrain operators&
Excessive solids *uild up
increases carryover and
effects filter
performance&
Effectiveness
relia*ility @
structural integrity
of ra'ing system&
Sludge *lan'et
control&
Clarifier ra'e systems are regularly maintained&
5efer procedure M.=,.,&
Clarifiers are operated to run %ith no sludge
*lan'et& Solids go to se%er& Clarifiers not used
%hen plant in Contact 8iltration mode&
5efer S
-
8/17/2019 w Sp 170805 Appa
20/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
Efficacy and
relia*ility of 6osing
Anit&
Maintenance schedule component redundancy
accessi*ility to spares @ tech& "dvice&
> hour Maintenance cover
availa*le& (refer S&
-
8/17/2019 w Sp 170805 Appa
21/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
8lo% control&
#erformance
management?
analysis&
1ac'%ashing
procedure&
+ur*idity Control&
"fter hours tur*idity
control&
Mechanical and
electrical
maintenance of
*ac'%ashing
system&
8iltered %ater tur*&
f J=&> B+A
K=&> for > hrs L
report
K=&> for hrs L
shutdo%n
K=&- for > hrs L
shutdo%n
single filterK=&- for
>hrs L ta'e off line
"cid sol& "l J=&,
mg?,- 8iltration @ +ur*idity
Control at Molendinar
"ll filters have tur*idity meters %hich are
alarmed as is composite tur*idity meter&
5efer S
-
8/17/2019 w Sp 170805 Appa
22/51
"ctivity or process
step #otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correct ive act ions
"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
-
8/17/2019 w Sp 170805 Appa
23/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
6isinfection
(Chlorination)
8ailure to eliminate
chlorine sensitive
pathogens&
+aste and odour
pro*lems&
+!M formation&
"vaila*ility @
/uality of Cl> supply
Efficacy and
relia*ility of dosing
unit& (Chlorine
delivery unit is not
flo% sensitive)&
6osage
determination @
control&
Cl> of ,.,&mg?l
%ith p! to &
Chlorine K,&
orJ,&=K7hrsLreport
K- or J=&> for , hr L
contact manager for
shutdo%n advice&
Q" supplier (alternate supplier avail&)
Maintenance schedule component redundancy
accessi*ility to spares @ tech& advice is
availa*le&
Wee'ly *acterial testing is carried out on ra% @
pota*le %ater & Emphasis placed on strict filter
tur*idity performance (continuous) and chlorine
control (continuous)
#rocedure M.=,.>, 6isinfection Control at
MolendinarF
"lternative sources availa*le&
> hour maintenance cover
availa*le& (refer S
-
8/17/2019 w Sp 170805 Appa
24/51
"ctivity or process
step
#otential ha$ards Control issues Critical or
operational limits
Monitoring and ?or con trol measures Correc tive act ions
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=
-
8/17/2019 w Sp 170805 Appa
25/51
+a*le "-2 Storage and reticulation system
"ctivity or #rocess
Step
#otential !a$ards Control Issues Cr it ical perati onal
-
8/17/2019 w Sp 170805 Appa
26/51
Critical perational Monitoring and?or Control Measures
-
8/17/2019 w Sp 170805 Appa
27/51
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
e
f
e
r
t
o
t
h
e
M
.
=
r
a
n
g
e
o
f
p
r
o
c
e
d
-
8/17/2019 w Sp 170805 Appa
28/51
u
r
es
%
h
i
c
h
c
o
v
e
r
a
l
l
m
a
i
n
t
en
a
n
c
e
a
n
d
r
e
p
a
i
r
a
c
t
i
v
i
ti
e
s
c
a
r
r
i
e
d
o
u
t
*
y
p
e
r
at
i
o
n
s
@
M
a
i
n
t
e
n
a
n
c
e
&
Contractor control B"
Meter
contractors
formal
detailing
instructions&
Infrastructure
inspectors
E
n
f
o
r
c
e
a
g
r
e
e
m
e
n
t
p
e
n
a
l
ty
c
l
a
u
s
e
s
&
S
u
*
.
s
t
a
n
d
ar
d
%
o
r
'
c
a
n
*
e
r e
0
e
c
t
e
d
a
t
a
n
y
s
t
a
g
e
o
f
c
o
n
t
r
a
c
t
&
-
8/17/2019 w Sp 170805 Appa
29/51
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
5
e
f
e
r
S
e
r
v
i
c
e
<
e
v
e
l
"
g
r
e
e
m
e
n
t
%
i
t
h
p
e
r
a
t
-
8/17/2019 w Sp 170805 Appa
30/51
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
-
8/17/2019 w Sp 170805 Appa
31/51
#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&
-
8/17/2019 w Sp 170805 Appa
32/51
f
Wa
t
e
r
5
e
t
i
cu
l
a
t
io
n
S
ys
t
e
m
&
-
8/17/2019 w Sp 170805 Appa
33/51
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
-
8/17/2019 w Sp 170805 Appa
34/51
5
e
f e
r
p
r
o
c
e
d
ur
e
M
.
=
.
=D
1
e
e
n
leigh
5echlo
rinationF and
1ul'
Water
"gree
ment
%ith
1ris*a
ne
Wa
ter@
-
8/17/2019 w Sp 170805 Appa
35/51
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
-
8/17/2019 w Sp 170805 Appa
36/51
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
-
8/17/2019 w Sp 170805 Appa
37/51
+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;
-
8/17/2019 w Sp 170805 Appa
38/51
CommentsCri ti ca l Cont ro l #oint Crit ica l or pera tional Hal idat ion
,=)
Coagulation flocculation @
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
Coagulation flocculation @
settling p! Control of 6osed Water
,=
-
8/17/2019 w Sp 170805 Appa
39/51
CommentsCritical or perational
-
8/17/2019 w Sp 170805 Appa
40/51
Coagulation flocculation @
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&
,>
-
8/17/2019 w Sp 170805 Appa
41/51
HalidationCritical Control #oint CommentsCritical or perational
-
8/17/2019 w Sp 170805 Appa
42/51
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&
,
-
8/17/2019 w Sp 170805 Appa
43/51
"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"<
-
8/17/2019 w Sp 170805 Appa
44/51
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
-
8/17/2019 w Sp 170805 Appa
45/51
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&
,
-
8/17/2019 w Sp 170805 Appa
46/51
Each of the six filters at Molendinar is e/uipped %ith Great
-
8/17/2019 w Sp 170805 Appa
47/51
*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&
-
8/17/2019 w Sp 170805 Appa
48/51
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
-
8/17/2019 w Sp 170805 Appa
49/51
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 #
-
8/17/2019 w Sp 170805 Appa
50/51
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>
-
8/17/2019 w Sp 170805 Appa
51/51
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