Intelligent Water Networks – is science the key to driving productivity and efficiency in urban water?
Dr Joel Byrnes| Associate Director, AECOM
November 2012
Intelligent Water Networks – Background•Intelligent Water Networks (IWN) Consortium of Victorian Water
Authorities, working with state government
•Industry Driver: The increasing costs and consequences associated with operating water, wastewater drainage networks
•Traditional approaches to monitoring condition and deterioration are invasive and costly....
•....But, monitoring technology advances have occurred in other sectors that are now relevant to water/wastewater/drainage networks
Intelligent Water Networks – Background
Task: Identify, review and prioritise monitoring technologies for enhanced asset management of
water/wastewater/drainage networks
Mapping technologies to asset types and performance indicators
•Water sector avoiding monitoring technologies that simply provide scientific innovation
Technologies providing business benefits merit further development
•Identified technologies must be matched to key assets and performance indicators
•Satisfy assessment criteria that clearly demonstrate the value of implementing technology
•Demonstrate economic efficiency in technology investment
Mapping technologies to asset types and performance indicators
Use “Failure pathways” to identify system parameters that can be monitored for each asset type
EVENTBURST MAIN
(ALL)Fracture/blown section
Perforation (i.e. localised corrosion
pitting, ductile rupture
(ALL)Surge pressure/cyclic
pressure
(ALL)Inappropriate pump/valve
operation
EVENTLEAK
(ALL apart from PE)
Joint leak
(ALL)Pipe deformation
(ALL)Pipe bending (broken
back)
(AC, MS(CL), DI (CL), CI (CL))
Internal corrosion
(MSCL, DICL, CICL)
Spalling of internal cement mortar lining
(MSCL, DICL, CICL)
Leaching of internal cement mortar lining
(AC, MSCL, DICL, CICL)
Source water, chemistry change (to soft water)
AC, MS(CL), DI(CL), CI(CL)External corrosion
(MS(CL), DI (CL), CI (CL))
External coating breach
(ALL)Soil movement
(ALL apart from PE)
Soil environment change
(ALL)Climate variables (temp,
rainfall)
(MS(CL))Cathodic protection
failure
Water supply -Burst & LeakMaterials key
AC = asbestos cementCI(CL) = cast iron (cement lined)DI(CL) = ductile iron (cement lined)GRP = glass reinforced plasticMS(CL) = mild steel (cement lined)PE = polyethylenePVC = polyvinyl chlorideRC = reinforced concrete
Rising Mains – Sewage Spill
EVENT SEWAGESPILL
(ALL)Pipe Fracture/Collapse
and/or Blockage
(ALL)Surge pressure/cyclic
pressure beyond design limit
Inappropriate pump/valve operation
(ALL apart from PE/ PVC)
Corrosion of pipe wall/
Loss of strength
(ALL apart from PE/ PVC)
Loss of soil support/voiding
(ALL apart from PE/ PVC)
Axial bending of small diameter pipe (i.e. 'broken back')
(ALL apart from PE/PVC)
Internal corrosion
MS (CL)Cathodic protection failure
(ALL apart from PE/ PVC)
External corrosion
(MS, DI )External coating
breach
(ALL apart from PE/ PVC)
Sewage exfiltration
(ALL apart from PE)
J oint Leak
(ALL)Pipe deformation)
(ALL)Soil Movement
(ALL)Soil environment
change
(ALL)Climate variables (temp, rainfall)
(ALL)Aggressive chemicals
discharged into sewer
(ALL apart from PE/ PVC)
Sulphuric acid generation
(ALL apart from PE/ PVC)
Air release valve not functioning
(ALL apart from PE/ PVC)
Presence of occluded air
(ALL apart from PE/ PVC)
Sulphide generation in sewer
(ALL apart from PE)
Tree root penetration
Materials key
AC = asbestos cementCI(CL) = cast iron (cement lined)DI(CL) = ductile iron (cement lined)GRP = glass reinforced plasticMS(CL) = mild steel (cement lined)PE = polyethylenePVC = polyvinyl chlorideRC = reinforced concrete
Failure pathway diagrams provides constraint for identifying relevant technologies
Mapping technologies to asset types and performance indicators
Tech
ID
Technology Asset type (s) Relevant failure event Primary distress indicator and pathway
A Acoustic instrumentation to monitor head loss/roughness/blockage Gravity Sewer Pipe Blockage (Reduced sewer
conveyance capacity)
Pipe blockage, Local constriction to flow
B Flow velocity monitoring to detect sedimentation Gravity Sewer Pipe Blockage (Reduced sewer
conveyance capacity), Sewage spill
Decreased flow velocities(insufficient for sedimentation
suspension), siltation, blockage, sulphide generation
through to internal corrosion, collapse
C Flow monitoring to detect blockage in gravity sewers (Penine Water
Group, Univ Sheffield)
Gravity Sewer Pipe Blockage (Reduced sewer
conveyance capacity)
Pipe blockage, Local constriction to flow
D Real time monitoring of dissolved Sulphide in sewers Gravity Sewer Sewage spill Sulphide generation, internal corrosion, collapse
E Pressure transients to detect internal deterioration Water Burst main Spalling of cement mortar lining, internal corrosion
through to burst main
E Pressure transients to detect presence of air pockets Sewer rising mains Sewage spill Presence of occluded air, through to sulphuric acid
generation
F Optical fibre monitoring for structural condition (External) Gravity Sewer Sewage spill Soil movement, pipe deformation, Joint Leak
F Optical fibre monitoring for structural condition (External) Sewer rising mains Sewage spill Soil movement, pipe deformation, Joint Leak
F Optical fibre monitoring for structural condition (External) Water Leak, Burst main Soil movement, pipe deformation, Joint Leak
F Optical fibre monitoring for structural condition (Internal) Water Leak, Burst main Surge pressure/cyclic pressure, Joint leak
G Soil temperature/moisture/pressure sensing to infer structural
condition
Gravity Sewer Sewage spill Soil environment change, soil movement, through to
sewage spill
G Soil temperature/moisture/pressure sensing to infer structural
condition
Sewer rising mains Sewage spill Soil environment change, soil movement, through to
sewage spill
G Soil temperature/moisture/pressure sensing to infer structural
condition
Water Leak, Burst main Soil environment change, soil movement, through to leak,
burst main
H In-situ Linear Polarisation Resistance to monitor soil corrosivity Sewer rising mains Sewage spill Soil environment change, external corrosion through to
sewage spill
H In-situ Linear Polarisation Resistance to monitor soil corrosivity Water Leak, Burst main Soil environment change, external corrosion through to
burst main, leak
I Surface based resistivity to monitor soil corrosivity Sewer rising mains Sewage spill Soil environment change, external corrosion through to
sewage spill
I Surface based resistivity to monitor soil corrosivity Water Leak, Burst main Soil environment change, external corrosion through to
burst main, leak
Rising Mains – Sewage Spill
EVENT SEWAGESPILL
(ALL)Pipe Fracture/Collapse
and/or Blockage
(ALL)Surge pressure/cyclic
pressure beyond design limit
Inappropriate pump/valve operation
(ALL apart from PE/ PVC)
Corrosion of pipe wall/
Loss of strength
(ALL apart from PE/ PVC)
Loss of soil support/voiding
(ALL apart from PE/ PVC)
Axial bending of small diameter pipe (i.e. 'broken back')
(ALL apart from PE/PVC)
Internal corrosion
MS (CL)Cathodic protection failure
(ALL apart from PE/ PVC)
External corrosion
(MS, DI )External coating
breach
(ALL apart from PE/ PVC)
Sewage exfiltration
(ALL apart from PE)
J oint Leak
(ALL)Pipe deformation)
(ALL)Soil Movement
(ALL)Soil environment
change
(ALL)Climate variables (temp, rainfall)
(ALL)Aggressive chemicals
discharged into sewer
(ALL apart from PE/ PVC)
Sulphuric acid generation
(ALL apart from PE/ PVC)
Air release valve not functioning
(ALL apart from PE/ PVC)
Presence of occluded air
(ALL apart from PE/ PVC)
Sulphide generation in sewer
(ALL apart from PE)
Tree root penetration
Materials key
AC = asbestos cementCI(CL) = cast iron (cement lined)DI(CL) = ductile iron (cement lined)GRP = glass reinforced plasticMS(CL) = mild steel (cement lined)PE = polyethylenePVC = polyvinyl chlorideRC = reinforced concrete
Rising Mains – Sewage Spill
EVENT SEWAGESPILL
(ALL)Pipe Fracture/Collapse
and/or Blockage
(ALL)Surge pressure/cyclic
pressure beyond design limit
Inappropriate pump/valve operation
(ALL apart from PE/PVC)
Corrosion of pipe wall/Loss of strength
(ALL apart from PE/PVC)
Loss of soil support/voiding
(ALL apart from PE/PVC)
Axial bending of small diameter pipe (i.e.
'broken back')
(ALL apart from PE/PVC)
Internal corrosion
MS (CL)Cathodic protection failure
(ALL apart from PE/PVC)
External corrosion
(MS, DI)External coating
breach
(ALL apart from PE/PVC)
Sewage exfiltration
(ALL apart from PE)Joint Leak
(ALL)Pipe deformation)
(ALL)Soil Movement
(ALL)Soil environment
change
(ALL)Climate variables (temp,
rainfall)
(ALL)Aggressive chemicals discharged into sewer
(ALL apart from PE/PVC)
Sulphuric acid generation
(ALL apart from PE/PVC)
Air release valve not functioning
(ALL apart from PE/PVC)
Presence of occluded air
(ALL apart from PE/PVC)
Sulphide generation in sewer
(ALL apart from PE)Tree root penetration
Tech ID: ETech ID: E
Tech ID: M
Tech ID: N
Tech ID: F, G, H, ITech ID: H, I
Tech ID: F, G
Tech ID: FTech ID: F, G, OTech ID: F, G, O
Tech ID: FTech ID: F
Tech ID: F
L
L
Tech ID: F, G
Materials key
AC = asbestos cementCI(CL) = cast iron (cement lined)DI(CL) = ductile iron (cement lined)GRP = glass reinforced plasticMS(CL) = mild steel (cement lined)PE = polyethylenePVC = polyvinyl chlorideRC = reinforced concrete
Can ensure that technologies are relevant to actual deterioration processes
• Have identified/matched monitoring technologies to various stages of failure pathway for key assets
• But: Water sector need to assess value proposition in each case and prioritise technologies for further development
• Multi Criteria Assessment to compare technologies against:Potential to save operational response costs and reactive maintenance
costsPotential to save capital through renewal deferralRelative cost/asset coverage lengthFailure pathway coverage & ability for early detectionPotential to reduce social/environmental impacts
Assessment criteria for monitoring technologies
Assessment criteria for monitoring technologies
TECH ID TECHNOLOGY DESCRIPTION
CRITERIA WEIGHTING AND DESCRIPTION
OVERALL SCORE
OVERALL RANKING
4 4 3 2 3 3 3 3 3 2 2
Potential to save opex response
costs
Potential to save
preventative maintenance
costs
Potential to save capital
through renewals or
augmentation deferral
Potential to improve Levels of
Service at the same cost
Relative cost to procure and
install technology
Relative cost to operate
and maintain technology
Relative asset coverage
(length) per monitoring
device
Extent of failure pathway
addressed per monitoring
device
Potential to reduce
disruption through early
failure detection
Potential to reduce
environmental impacts
Potential to provide social
benefit
TECHNOLOGY RANKING (1 = Worst, 5 = Best)
AAcoustic instrumentation to monitor head loss/roughness/blockage
3 3 3 3 4 3 3 2 3 2 3 94 16 of 19
BFlow velocity monitoring to detect sedimentation
3 3 3 3 4 4 4 1 3 2 2 95 15 of 19
CFlow monitoring to detect blockage in gravity sewers (Penine Water Group, Univ Sheffield)
3 3 3 3 3 4 5 3 3 4 4 109 2 of 19
DReal time monitoring of dissolved Sulphide in sewers
4 4 4 3 2 3 2 2 5 2 3 102 10 of 19
EPressure transients to detect internal deterioration
4 4 4 3 2 3 4 3 4 2 3 108 3 of 19
FOptical fibre monitoring for structural condition (External)
4 4 4 3 2 2 4 4 4 2 3 108 3 of 19
GSoil temperature/moisture/pressure sensing to infer structural condition
4 4 4 3 3 4 1 4 4 2 3 108 3 of 19
HIn-situ Linear Polarisation Resistance to monitor soil corrosivity
4 4 4 3 2 3 1 3 4 2 3 99 12 of 19
ISurface based resistivity to monitor soil corrosivity
4 4 4 3 3 3 3 3 4 2 3 108 3 of 19
JContinuous monitoring of H2S gas in sewer networks
4 4 4 3 2 3 2 2 4 2 3 99 12 of 19
KStatistical inference monitoring of existing network data
3 3 3 3 3 3 5 3 3 4 4 106 8 of 19
LPump performance and condition monitoring (Yatesmeter)
3 3 3 3 4 4 1 1 3 2 2 86 19 of 19
MIn pipe sewage chemistry monitoring (CSIRO)
4 4 4 3 3 3 2 2 4 2 3 102 10 of 19
N Cathodic protection monitoring 4 4 4 3 4 4 3 1 4 2 3 108 3 of 19
O Infra-red thermography 4 4 4 3 1 2 2 2 3 2 3 90 17 of 19
P Real time hydraulic modelling 3 3 3 3 3 3 5 3 3 4 4 106 8 of 19
Q Real time water quality monitoring 3 3 3 3 3 3 2 2 3 2 3 88 18 of 19
R Permanent digital noise logging 3 4 3 3 4 3 3 3 4 4 4 110 1 of 19
S Ground penetrating radar 4 4 4 3 2 3 1 3 4 2 3 99 12 of 19
Prioritised IWN technologies• Top 6 IWN technologies from MCA prioritisation
“Detection” technologies to minimise operational response and social/environmental impacts of asset failures
“Predictor” technologies for early indication of deterioration and potential failure
Priority Tech ID Technology Description
1 R Permanent digital noise logging for leak detection in water mains
2 C Flow monitoring to detect blockage in gravity sewers
3 F Optical fibre monitoring for structural condition
E Pressure transients to detect internal deterioration
G Soil temperature/moisture/pressure sensing to infer structural condition
I Surface based resistivity to monitor soil corrosivity
Digital noise logging for water main leak detection
Cost-Benefit Analysis of Technologies• Following Multi-Criteria Assessment, a quantitative analysis also
undertaken for the most promising technologies• Intended to predict the financial impact on a water utility during
a pilot trial• Costs – capital, operating, maintenance, benefit realisation• Benefits – deferred capital, water saving, ‘tech replacement’
saving, reduced reactive maintenance, environmental and social benefits
Cost-Benefit Analysis of Technologies• For each technology, the benefit-cost ratio, net present value ($)
and return on investment (years) were assessed• Costs and benefits were calculated for a hypothetical trial area• A sensitivity analysis was also undertaken to identify
parameters that exert the greatest influence on NPV outcome
Cost-Benefit Tool: Example of Output
NPV outcomes most sensitive to reactive maintenance savings, but can be used to select
pilot trial areas
Cost-Benefit Analysis of Technologies: Recommendations
Tech ID Technology Description
NPV Sensitivity
Suggested pilot trial guidelines to maximise NPV25-Yr NPV (Average)
25-Yr NPV (High)
25-Yr NPV (Low)
R Permanent digital noise logging -$241,302 +$197,681 -$451,418
Large diameter, relatively old metallic mains in critical locations. This will target high consequence
mains and test hypothesis that noise loggers can provide early detection ability to pre-empt high
consequence bursts
Water mains constructed of MDPE. This will verify the enhanced performance of noise loggers in leak
detection for low stiffness, noise-attenuating materials where traditional leak detection is difficult.
FOptical fibre monitoring for structural
condition (External)+$26,513 +465,496 -$183,603
New pipe installations in high consequence areas. This presents an opportunity to investigate the
efficacy of external application of fibre optics on new mains without incurring the cost of exposing
mains and re-instating.
For Mild Steel mains, areas where stray current corrosion is possible, the installation of fibre optics
should be considered to detect leakage noise from localised corrosion in areas of coating breakdown
and inadequate cathodic protection
For GRP mains, fibre optics should be considered when bending stress from differential soil
movement is thought to be possible. Should also be considered for new installations where loss of
soil support and deflection thought to be possible.
Abandoned mains in low consequence areas. This presents an opportunity to investigate the
installation of fibre optics external to an existing buried main to detect changes in applied loads ahead
of failure.
ISurface based resistivity to monitor soil
corrosivity+$173,460 +$612,443 -$36,656
Large diameter, relatively old metallic mains in critical locations. This will target high consequence
mains and test the hypothesis that method can provide early detection ability to pre-empt high
consequence bursts
Long mains in areas of the network where localised saturated clay soils of low resistivity are thought
to exist.
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