WSDP: MODULE 2
TOPIC 6: OPERATION AND MAINTENANCE PLAN
6. OPERATION AND MAINTENANCE PLAN
The focus on improvement of levels of service through creating new infrastructure at great
cost results often in overlooking the importance of the development and implementation of
sound asset management practices.
Through the assessment of this important function WSAs are enabled to identify areas of
concern and it should form the base for the development of an Asset Management Plan.
Neglecting the implementation of best practice operational and maintenance procedures
would result in ineffective service delivery and shortened life span expectancy of assets.
Additional capital expenditure for refurbishment or replacement will eventually be
unavoidable.
The two important aspects of asset management under consideration are:

Operations

Maintenance
6.1. OPERATION AND MAINTENANCE
6.1.1. Water Network Performance
Water network performance is monitored by recording bursts on particular lengths of
pipework. Lengths of pipework have been relayed in past financial years yet other sections
continue to age and exhibit increased burst frequencies.
An examination of burst main statistics indicates that the predominant pipe size and type
prone to failure are pipe sections made up of fibre-cement in the sizes of 100 mm and below.
Noteworthy observations are that in the South Peninsula and Tygerberg areas, the failing
pipework is 100 mm fibre-cement. Both of these districts have similar lengths of pipework
and ages (approximately 50 years).
Helderberg and Blaauwberg Districts experience failure both with 100 mm fibre-cement pipe
and fibre-cement pipe of less than 100 mm nominal diameter.
In the old Cape Town municipal area the water reticulation performance has benefitted from
past infrastructural renewal and therefore has fewer sections of pipe approaching the unserviceability condition.
2.95
Khayelitsha is a relatively new network and does not have pipe sections that require
replacement.
A breakdown of suggested pipe replacement to achieve a nominal reduction in burst
water mains is as indicated in the following table:
Table 1: Water Pipework to be replaced in 2012/13
District
Proposed relay Length (m)
2012/13
District 1
35 560
District 2
4 570
District 3
-
District 4
16 131
District 5
29 012
District 6/7 and 8
15 599
Total
100 872 (±100km)
Source: Five Year Water Replacement Programme (per District) obtained from Reticulation District officials, 2012/13
Khayelitsha District has the best performance, well within the target of 20 bursts per 100 km
per year. This is because this network is, on the whole, the newest in the Metro. The network
of the Cape Town district, whilst being the oldest, has a fairly stable performance but lies
above the target performance. The reason for this is that it has benefitted from sustained
investment and optimal operations over the years (albeit reduced investment due to
diversion of funds to other Metro areas with poorer infrastructural performance).
Table 2: Reticulation Statistics (USPC 2012/06 (v08)
WATER
NETWORKS
Repair to
Burst Water
Mains
Water Mains
Replaced (m)
2011/12 YEAR STATS AS AT END JUNE 2012
BLAAUWCAPE
HELDERKHAYEBERG
TOWN
BERG
LITSHA
SOUTH
PEN.
TYGERBERG
YTD - ANNUAL COMPARISON
YTDYTDYTD2011/12
2010/11
2009/10
790
594
784
30
794
965
3 957
6 523
6 169
39 049
13 456
5 745
5
28 448
3 272
89 975
57 419
53 104
2.96
For the 2011/12 financial year it was suggested that ±150km (Five Year Replacement
Programme for Reticulation Networks, Inclusive of Operational Improvement Proposals,
February 2012) of the water network be replaced. Approximately 60% of the recommended
pipe replacement has taken place. This suggested that the burst frequency could have been
reduced even further. Over the first 6 months of the 2012 calendar year the burst main rate
was 35 bursts/100km/year.
6.1.2. Sewer Network Performance
Whilst reported sewer blockages are quickly attended to and the cause of the blockages are
recorded, there is only a minimum of inspections of the sewers to determine if underlying
causes of blockages are related to infrastructural defects. There is a dire need for technical
staff to carry out this function.
Predominant infrastructural failures are related to the use of pitch fibre pipe, joint failure in
clay pipework and corrosion of cement bulk pipework that carries sewage that is releasing
aggressive gases.
Accordingly, sewer replacement is premised on the replacement of 420 km pitch fibre
sewers and clay sewers over a five year period.
The condition of bulk sewer pipework is also of concern. Collapses in this pipework indicate
that there is an urgent need to determine its condition and thereafter carry out any required
rehabilitation before the condition deteriorates to the extent where these sewers have to be
reconstructed at double the cost.
GIS records indicate the following:
Table 3: Estimated Sewer Rehabilitation Lengths
Material
Length (m)
Pitch fibre
128 260
Clay sewers
291 260
Bulk sewers
359 186
Source: Budget Plan (Vol 4), Reticulation, Five year replacement programme
2.97
6.1.3. Water Process Control, Maintenance and Management Skill
The current classification of the WTW’s, is according to Section 26 of the National Water
Act (Act No.36 of 1998).
Monitoring Process
The quality of water produced at the CCT’s water treatment plants is strictly monitored
on a continual basis to ensure compliance with the South African National Standard
241:2006 on drinking water quality. The Scientific Services Branch conducts routine
sampling and analysis of potable water produced at all water treatment plants, as well as
inspection of treatment processes.
Scientific services have acquired SANS 17025 certification for laboratory quality testing.
Expansion of the laboratory is a necessity for improving its capability to undertake a wide
spectrum of tests.
The water quality report below indicates the analytical data and approximate distribution
for Cape Town drinking water as at the end of June 2012. The South African National
Standards (SANS 241:2006) Specification for a Class I and II water is also stipulated on
this report. This report indicates the quality of the drinking water leaving each of the
major water treatment plants and the approximate distribution areas they service.
Table 4: Class 1: Drinking Water Quality for June 2012 (SANS 241 requirements per
population size; 1 sample: 20 000 population)
Water Supply
Outlets
Sample
Points
Per
Water
Supply
Outlet
Sample
Points
Sampled
Number of Samples
Taken for June
Chemi
cal
Microbio
logical
% Compliance SANS 241
May Month
Chemi
cal
Microbio
logical
12 Month Rolling
Average
Chemi
Micro
cal
biological
Water
Treatment
Plants
10
9
32
28
99
100
99
99
Reservoir *
26
23
76
86
100
100
98
99
Distribution *
107
90
333
352
100
100
98
100
Informal
Settlements *
43
35
67
64
100
98
98
98
186
157
508
530
100
100
98
99
Total
2.98
REMARKS:
Chemical Results: Most of the distribution sampling points that fail can be attributed to high
Turbidity results. OBW 09, SPW 11, BBW 06, TBW 02 and Informal Settlement 32 fail due to
high pH values. Sample points Atlantis Clinic, Atlantis Pella 40 and BBW 01 fail due to high
Iron values. Informal Settlement has 29 fails due to high Iron and Lead values. Overall the
water is safe to drink.
The determinants at the Water Treatment Plants that do not comply with SANS 241 are
Aluminium and Turbidity.
*Please note:
Chemical Analyses:

pH, Conductivity, Turbidity and Alkalinity were done weekly.

Aluminium, Chloride, Calcium, Iron, Manganese, Potassium, Sodium, Sulphate,
Nitrate/Nitrite and TDS were done every 8 to 9 weeks.
Microbiology Results: In the month of November the following sample exceeded the SANS
241 guideline for Bacteriological quality of drinking water: On 2011-11-14 MBW 04,
Newlands Reservoir outlet to Wynberg had an Escherichia coli (E. coli) count of 1
CFU/100ml. On 2011-11-15 it had an E.coli count of 3 CFU’s/ml. On 2011-11-16 the result
was <1 CFU/100ml and hence complied with the guideline. The informal settlement results
that exceeded the guideline are not included. Please see the comments below
Informal Settlements: The non-compliance of the informal settlements to the South African
National Drinking Water Standard (SANS 241) can be attributable to the following:

Plastic communal taps are being used for sampling. Because of plastic material taps are
not flamed prior to samples collection.

Taps are not dedicated for sampling only; and are used by the community.

Location of sample taps in close proximity to or just behind the communal toilets can
introduce cross contamination to the tap as users wash, touch and drink directly from the
taps.

Taps are often dirty and leaking.
2.99
6.1.4. Waste Water Operations (Process Control), Maintenance and Management Skill
An Operational and Compliance Monitoring Programme that meets the requirements of
DWA as stipulated in the Green Drop Criteria was drawn up by CCT and is implemented by
the Municipality. Operational samples are taken on a daily basis at all the WWTWs. The
compliance samples that are taken on a monthly basis at all the WWTWs are analysed at
CoCT accredited Scientific Services laboratories and monthly monitoring and inspection
reports are compiled.
Table 5: Waste Water Treatment Non-Compliance as at June 2012
WWTW
Bellville
PROBLEM
DEFINITION
No sample complying
on COD, Ammonia
and E.Coli. One
sample complying on
TSS.
CAUSES
REMEDIAL ACTIONS
Broken diffusers in North
and Centre biological
reactors are causing poor
aeration of the biomass.
Experienced belt press
mechanical breakdowns
which have reduced the
mass of sludge to be
wasted per day. The UV
disinfection system is not
in operation due to the
poor settling pond
effluent.
Construction of the new
Membrane Works(20Ml/d) is in
progress(long-term plan).A task
group comprising Operations
and EAM electrical and
mechanical sections has been
formed to focus on improving the
reliability of the dewatering
equipment. The settlement
ponds are in the process of
being cleaned out. The by-pass
pipeline to the UV lights is in
progress – this will allow the SST
effluent to flow directly to the UV
disinfection unit.
The maturation ponds and
bypass channel are being
cleaned. At the end of June 2012
the bypass pipeline was brought
into operation.
Borcherds
Quarry
Non-compliance on all
the parameters
Maturation ponds are full
of sludge which is
contamination the
secondary settling tank
effluent which is generally
compliant with the
General Standard.
Klipheuwe
l
Non-complying TSS,
COD and Ammonia
The septic tank is being
cleaned out
This Process was completed and
the plant is recovering
Gordons
Bay
Non-compliance on
COD
Foaming in the reactor
Dosing of chlorine
Maturation Ponds
contaminated with sludge
due to failure of
Archimedean Screw
Pumps at Intermediate
Pump station.
Removing sludge from
maturation ponds. The plant
effluent compliant before
entering maturation ponds.
Mitchells
Plain
Non-compliance on
ammonia and E.Coli
2.100
6.1.5.
Status of Equipment and Plant on Wastewater Treatment Works (as at January 2012)
Table 6: Status of Equipment and Plant on Wastewater Treatment Works
WWTW
1
Athlone
2
Description
Primary Tanks, 3 new tanks
being installed
Grit removal unit appears
unsatisfactory.
3
Gravity thickener - inadequate
4
5
Required
required. This is in
not applicable at this
stage – investigation
new thickener
required
refurbishment – this
Holder leaking
has been
refurbishment – Retic
Demolish
Mixed Liquor & RAS Pumps
9
10
Replacement
may be required
sludge
Cleaning
not completed yet
Sludge Beds are a fire hazard
Require cleaning
Blower #1: faulty
Interstage screw pump
Bellville
external contractor
Internal costs. Job
Requires completion
Part of the capital
project
Part of the capital
project
Repair vs replacement
being investigated
Repair vs replace
In progress
Inlet screen 2 out of
Repair chain and
Part of future upgrade
commission
placed in auto mode
plan
gearbox
13
obtained
Refurbishment/
incomplete
12
Quotations to be
Maturation Ponds full of
Outer Perimeter Fence
11
R 0.5 million
An appointment of an
years of age)
8
R 10 million
to confirm
require demolishing
require replacement (over 20
to be determined
Requires
Redundant tanks and
7
to be determined
is in progress
sand, gas lines corroded, Gas
pipelines and buildings
R 5 million
progress
Replacement or
partially blocked
Estimated Cost
One further tank
Anaerobic Digesters, full of
Cape Flats Sewer ex Athlone,
6
Intervention
2.101
14
Belt press 2&3 are out of
commission for repairs. are in
the process of being repaired
to improve sludge dewatering
Repair and align with
automation system
In progress
and removal
15
Blower # 3 is out of
commission
16
Requires repairs
Sludge cake pumps cannot
PLC needs to be set
accommodate full cake
to accommodate cake
volume
volumes produced
17
Pond 2 is out of commission
18
Needs to be lined with
clay or plastic
In progress
done
R 3 – 5 million – part
of current upgrade
project
Installation of Med/fine
screen pre-UV to
UV disinfection unit cannot
perform reliably – taken out of
prevent damage to UV
lights.
use
R 10 million – part of
current upgrade
project
Improvement in
effluent quality.
19
20
SSTs cannot accommodate
SST modification to
high flows.
improve settling
Standby generator not on
auto
21
22
Borcherds
Quarry
23
24
Re-use pumps not operational
Being replaced
Unable to separate dewatered
Need to automate
primary and secondary
centrifuge – being
sludges.
investigated
Blower 3 out of commission
Refurbish blower
due to vibration
motor – in progress
Ponds are full of sludge
25
PST 1 requires repairs to
scrapers and rope pulley
26
Ponds cleaning plan
for summer months.
In progress
Inlet Screw Pumps,
Screws and trough
Screws inefficient
require refurbishment
Cape Flats
27
Requires repair
Odour Control System
requires upgrading
Being planned
R 7 million – will be
part of future upgrade
project
In progress
R 1 million
R 350 000 - ongoing
In progress
done
R 5 million
To be determined
2.102
28
29
30
Primary Tank Bridges
Bridge Replacement
corroded
required
Aeration System requires
Aeration System
constant repair
requires replacement
R 10 million
R 0.5 million
Anaerobic Mixers inefficient
because of age and
Require replacement
R 0.4 million
Require replacement
R 8 million
breakdowns
31
Clarifier Bridges corroded
32
Costs to be
Aerobic Blowers are 30 years
old. Have been repaired but
established once the
Require replacement
will require replacement
contractor has
assessed the
problems
33
Blower #1 gearbox vibration
In progress
34
Boilers damaged
Needs repair
Being investigated
35
Green Point
Pumps require replacement
Currently underway
Part of capital project
36
Gordons Bay
Electrical Panels
To be replaced
In progress
37
Hout Bay
38
Macerator system inadequate
requires upgrading
Coarse and fine screen and
grit removal
39
Kraaifontein
Install fine screenings
and grit removal. This
R 2 million
will be planned
In planning
Anaerobic digester not in use.
Refurbish digesters.
Activated sludge plant is on
Will form part of a
extended aeration
general contract.
40
R 5 million
R 5 million
Pipeline is part of
By-pass pipeline and
pump station to be
Ponds are full of sludge
upgrade contract (in
progress).
constructed.
Completion date in
early 2012.
R 5 million for
cleaning – being
planned.
41
42
43
44
Macassar
Melkbosstrand
Mitchells Plain
Standby Generator beyond
Replacement. In
repair
planning
Degritter gearbox
Requires repairs
done
Require replacement
R 5 million
Require replacement
To be investigated
Coarse Screen outdated and
inadequate.
Inlet Screws, in poor
R2-3 million
2.103
mechanical condition.
45
Mechanical Screens, old
screen requires replacement
Requires replacement
R 200 million for the
and screening removal is
– Retic to plan
3rd Cape Flats sewer
inefficient
46
2 Screw Pumps
irreparable. One
Inter stage Pump Station
Screw being replaced.
Tender being repaired
R 10 million
to replace other with
submersible.
47
Reactors in bad repair
48
Aeration Blowers leak oil, and
breakdown
require refurbishment
R 0.5 million
Require replacement
R 0.2 million
49
An appointment of an
Clarifier, one floor has lifted
Need to be repaired
external contractor
may be required
50
Anaerobic Digesters off line:
require cleaning and pipework
Refurbishment
Internal costs. Job
required
not completed yet
and Belt Press breakdown
Replacement/
Part of the capital
problems with inclined
Refurbishment
project
Require refurbishment
done
Maturation Pond Fencing (2
Require fencing for
Part of future upgrade
km)
safety reason
plan
Demolish
R 0.3 million
and pumps require
refurbishment. Boilers need
overhaul.
51
Centrifuge out of commission
conveyor bearing failing.
52
Sludge Beds & Maturation
Ponds full of sludge
53
54
Redundant Equipment and
Building
55
Investigate the various
electronic problems.
Potsdam
UV disinfection performance
Place on automatic.
is erratic when on automatic
The maintenance
mode
tender is in progress
but there is a delay at
SCM.
R 0.3 million short
term
The maintenance
contract is expected
to be to the value of
R4 m
2.104
56
Install coarse screens
Inlet screens
upstream to remove
excessive rags
57
Simons Town
58
Low pH chemical dosing
Dosing plant being
equipment required
purchased.
Sludge Beds require
replacement with mechanical
Dewatering
59
Capital Projects – to
be investigated
R 8 million – in
rpogress
R 3 – 5 million
R 10 million
Replace blowers.
Interim repair to
Wesfleur
Domestic blowers
gearbox to reduce
R 7 million for
replacement
vibration was
completed.
60
61
62
63
Air pipeline corroded
Wildevoelvlei
Anaerobic Mixers are
unreliable
No standby Belt Press
Maturation Pond contain
sludge
64
Emergency repairs
R1.4m Has been
required.
repaired temporarily
Requires investigation
R 1 million
Standby Unit required
R 10 million
Require refurbishment
and/ or Disinfection
Part of capital project
Plant
Install coarse screens
Inlet screens
upstream to remove
R 5 million
excessive rags
2.105
6.1.6.
Status of Equipment and Plant at Bulk Water Installations (January 2012)
Table 7: Status of Equipment and Plant at Bulk Water Installations
Item
no
WTP
Description
Intervention Required
Estimated Cost
1
Faure WTP (BW)
Obsolete and aging
SCADA equipment
Replacement of all PLCs
R 6 million
2
Blackheath WTP (BW)
PAC Dosing System
Complete existing
contract –
Commissioning and
operational acceptance
period completed.
R 1 million
remaining of R7,7
million Contract
amount
3
Blackheath WTP (BW)
Treatment Residue Water
Recovery PS
Replace pump motor and
associated equipment –
Contract in progress
R 950 000
4
Steenbras WTP (BW)
Lime Storage and
Transfer system
Complete existing
contract – Contractor to
address items as per
snag list [Completed]
[Completed]
5
Voёlvlei WTP (BW)
Pump System Surge
Vessels
Phased refurbishment of
4 large pressure vessels
R 1,5 million
6
Voёlvlei WTP (BW)
Air-scour Blowers
Phased replacement of 2
blowers. One blower
replaced during 2010/11.
Second blower on order.
R 250 000
7
Witzands WTP (BW)
Acid Regeneration
System
Refurbish Acid System
R 2 million
8
Firlands PS (BW)
Obsolete and aging
Variable Frequency
Drives (VFD)
Replacement of 4 off
VSD’s
R 25 million
9
Kildare PS (BW)
Obsolete motors and
electrical control
equipment
Replace pump motors
and control equipment –
Contract in progress.
R 1 988 000
10
Molteno Reservoir PS No.
2 (BW)
Obsolete and aging pump
starter panel
Replace pump starter
panel – Contract in
progress.
R 415 000
2.106
6.1.7.
Status of Equipment and Plant on Pump Stations (as at January 2012)
Table 8: Status of Equipment and Plant on Pump Stations
Item
no
Pump Stations
Description
Intervention Required
Estimated
Cost
1
Gordon’s Bay 4
No 1 pump o/c No 2 Pump
blocked with Rags
Pump 1 removed for repairs
and pump 2 unblocked
R6 000.00
2
Simons Town 12
Heavy rain
Cleaned where possible
R1 000.00
3
Simonstown 1
Heavy rain
Cleaned where possible
R1 000.00
4
Simonstown 2
Heavy rain
Cleaned where possible
R1 000.00
5
Fleur Park
Pumps tripped due to rags
Reset pumps
R1 000.00
6
Lourens River
Pump # 3 tripped on over
temparature and 2nd pump
out for repair
Cleaned where possible
All 3 pumps tripped
Pumps reset (investigation
into cause of simultaneous
trip)
R2 000.00
7
Helderberg
R2 000.00
8
Summer Greens
Blocked rising main
Unblocked the main with jet
machine
R4 000.00
9
SarelCilliers
Electrical Panels
Replace
R 100 000
10
Serepta
Installation of diesel genset
Installation of diesel genset
R900 000
11
All Pump Stations
Telemetry upgrade
Upgrade (currently underway)
3.3Kv starters
Replace with standard 400v
Tender documents been
prepared
12
Karl Bremmer
R 10 000 000
R 1 800 000
13
HendonPark
Electrical Panels
Replace
R 100 000
14
Naomi Street
Electrical Panels
Replace
R 100 000
(Note:
Include equipment and plant with problems only.)
2.107