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Water Services Training Group. 13 th Annual Conference 10 th September 2009. Prioritising Mains for Rehabilitation/Replacement in a Large Urban Area. Alan Curran Technical Director RPS Consulting Engineers. Presentation Outline. Case Study - PowerPoint PPT PresentationTRANSCRIPT
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Water Services Training Group
13th Annual Conference
10th September 2009
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Prioritising Mains for Rehabilitation/Replacementin a Large Urban Area
Alan Curran
Technical Director
RPS Consulting Engineers
Presentation Outline
Case Study Dublin Region Watermains Rehabilitation Project
(DRWRP) – Client Dublin City Council Background Drivers & Challenges DMA Prioritisation Mains Selection Key Issues and Lessons Learned Results
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Background – Dublin Region Water Supply
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Greater Dublin Water Supply Area – 7 LA’s
Serves a population of 1.4m
Output 546 Ml/day
Sustainable Prod. 520 Ml/day
>8,000km water main
600 DMA’s
Future Demand Shortfall Identified in 1996
Background – Dublin Region Water Conservation Project (Stage 1 and 2) - 1998-2002
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Project Achieved: New Monitoring, Control and Data Systems
Metering and telemetry systems 530 District Meter areas (DMAs) Pressure management in selected areas A regional GIS system was established Regional hydraulic models were constructed Burst Record Database
Establishment of trained leakage control teams
Reduction in UFW from 42.5% to 28% (64Ml/day)
Pilot Leakage Driven Water Mains Rehabilitation
Confirmation that Rehabilitation Essential to Maintain Saving
Reduce below 28%
2002-2006 ALC and Systems Well Maintained
DRWRP Drivers and Objectives
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Overriding Purpose To Save water by Rehabilitating water mains
the greatest sustainable water savings, in a cost effective manner
Through an Integrated Approach: DMA Rehabilitation Hot Spot Rehabilitation – Isolated High Burst Frequency Mains Active Pressure Management DMA Optimisation Improved Metering infrastructure (where required)
While Recognising Risks Improved Service levels may offset savings
DRWRP Scope
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Scope:
Up to 4% of total mains length (~ 280 km) limited by budget
Higher rate required in long term
New development unlikely to be targeted (separate issues)
DMA Prioritisation(5 months)
DMA & Mains Appraisals &
Outline Design(7 months)
PHASE 1
PHASE 2
Detailed Designs and Construction
(5 years)
PHASE 3
Challenges – Urban Environment
Complexity of the Network Understanding Valve Density, Status and Connectivity
Handling Large Data Sets 8,500 km > 600 DMA’s 55,000 leak records
Density of Services CSL Risk Night Users
DMA Material and Age Mix Construction Cost Variability Access Issues – Traffic Management
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Challenges - Leakage
How to Achieve Success Which is ultimately measured at DMA Level
Selecting the Correct DMA’s Mains within the DMA’s
Accuracy of Leakage Calculations UFW does not = leakage PCC changes with weather and temp.
Leakage Fluctuates – How do you Measure? Which Assets are leaking? Which DMA’s/Assets will offer SUSTAINABLE savings? Which DMA’s Offer Best VFM? Customer Side Leakage
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
DMA Prioritisation - Objectives
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Collate & Check Data
AgreeCandidateDMA List
Characterise DMAs
Leakage/Cost
Prepare DMA Rankings
LA RankingSense Check
PrioritiseDMAs
Analyse DMALeakage
Assign LeakageTo DMA Assets
RankedDMA List
Identify TargetAssets
Prioritise DMAWork Packages
ProduceStrategy Report
StrategyReport
1. DMA Prioritisation
GISClient TelemetryBurst
RecordsNetworkModels
StakeHolders
LeakageInformation
Data Collection & “Fitness for Purpose” Assessment
All 7 Authorities, All DMAs System Implementation for Data
Management, Leakage Analysis and Ranking Characterise DMAs e.g. high leakage, high
pressure, unit costs All DMAs
Rank and identify shortlist DMAs (and reserves)
to match available budget “High-level” identification of target mains
within DMAs
DMA Prioritisation – Data
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Collate & Check Data
AgreeCandidateDMA List
Characterise DMAs
Leakage/Cost
Prepare DMA Rankings
LA RankingSense Check
PrioritiseDMAs
Analyse DMALeakage
Assign LeakageTo DMA Assets
RankedDMA List
Identify TargetAssets
Prioritise DMAWork Packages
ProduceStrategy Report
StrategyReport
1. Strategy Development & DMA Ranking
GISClient TelemetryBurst
RecordsNetworkModels
StakeHolders
LeakageInformation
GIS Network DMA Boundaries Geodirectory - Properties
Other Network Information Pressure Management Schematics
Telemetry Flow and Pressure
DMA Leakage Sheets (ESPB) Leak Repair Records
NRR Repeat Leak History
Network Models AZNP Detailed Design
Historical Rehabilitation Unit Costs
Collate & Check Data
Night Use Allowances
Households & Non households
MNF (m3/h)
CSP Leakage (m3/d)
Length of mains (km)
Hour – Day Factor
NNF (m3/h)
Total Leakage (m3/d)
M&C Leakage (m3/d)
M&C Leakage m3/km/d
DMA Ranking – Characterise DMA’s
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Mains & Comm. Pipe Leakage
SAVINGS
Lstart
Lend
Volume of leak repairs
[R]
NRR
NRR = Lend – Lstart + R
DMA Ranking – Characterise DMA’s
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Natural Rate of Rise in Leakage
SAVINGS
DMA Ranking – Characterise DMA’s
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Mains Rehabilitation Works Costs
COSTS
Total Unit Cost (€ per
m)Additional LC / Enabling works
Technique Unit Costs
Leak Repair Savings
Technique selection
Local Roads Policy
Stakeholders
Base Unit Costs
Reinst Unit Cost
Social Impacts
Present Value
DMA Ranking – Characterise DMA’s
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
€ / Ml saved
Mains Rehabilitation Works Costs
- Leak Repair CostSavings
€
Mains & Comm. Pipe Leakage
Natural Rate of Rise in Leakage
Ml
DMA RANKING
COSTS SAVINGS
DMA Selection and Prioritisation
8 Ranking passes carried out Apr-July 06
Each set reviewed LA’s – DMA Integrity sense check /local knowledge cross reference LA lists Unsuitable DMA’s removed Need for High burst frequency
programme agreed
Ranked List of 60 for Field Validation
Shortlist agreed matching DMAs “non-responsive” to ALC
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Mains Selection - Objectives
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
GISClient TelemetryBurst
RecordsNetworkModels
StakeHolders
LeakageInformation
DMA Appraisal Reports
2. Mains Prioritisation
Data Validation Candidate DMA’s
Data Analysis
Field Assessment
DMA Integrity
Step Testing
Meter/PRV Audits
Detailed Data Verification
Asset DataBurst
Records
LeakageAnalysis &
Assignment
Mains Scoring
Solutions
Other DataPipe Samples
No Action
Rehabilitation
Pressure Management
Validate/Improve Data in
Candidate DMA’s
Field Work
Desk Top
Operations Staff Interview
Leakage & Asset Data
Detailed Analysis and Scoring
Recommend Solution
Mains Prioritisation – Validation
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
GISClient TelemetryBurst
RecordsNetworkModels
StakeHolders
LeakageInformation
DMA Appraisal Reports
2. Mains Prioritisation
Data Validation Candidate DMA’s
Data Analysis
Field Assessment
DMA Integrity
Step Testing
Meter/PRV Audits
Detailed Data Verification
Asset DataBurst
Records
LeakageAnalysis &
Assignment
Mains Scoring
Solutions
Other DataPipe Samples
No Action
Rehabilitation
Pressure Management
60 Short-listed DMAs and Reserves only (40/20)
Integrity of the DMA’s Meter / PRV audits,
BV checks,
PZT,
Leakage Assignment Step-testing,
Burst Geo-referencing and Assignement
Operations Interview
Data Review – Leakage, Burst History, Customer Side Leakage Assessment
Mains Selection – DMA Integrity
Mains Selection – Assets
Mains Selection – Bursts
Mains Selection – Step Tests
STEP TEST ASSESSMENT FOR:-DMA REF:-DMA NAMEDATE VERIFIED:-
Step 1 Step 2 Step 3 Step 4 Step 5 TotalBASE DATA
No. Domestic Addresses 66 180 127 77 214 664No. Commercial Addresses 107 144 31 45 168 495No Buildings/Connections 72 135 109 71 106 493Exceptional Night Use (m3/Hr) 0.2 0.0 0.0 0.1 0.0 0.3
Bursts 57 55 9 9 28 158Mains and Mains Fittings Leaks 28 37 4 3 9 81Comms and Comms Fittings Leaks 27 17 4 5 9 62Customer Supply Pipe and CSP Fittings Leaks 2 1 1 1 10 15
Length Target Mains (m) 713 1,182 3 446 1,148 3,492GIS Length of Mains (m) 2,172 1,665 887 458 1,731 6,914Length Mains Missing from GIS (m) 0 0 0 0 0 0Total Length of Mains (m) 2,172 1,665 887 458 1,731 6,914
Current DRWRP Project 14.00 9.68 8.87 8.46 2.91 43.92DRWCP Study - 1.05 18.65 2.10 4.50 26.30
Hour to Day Factor 20.3 20.3 20.3 20.3 20.3 20.3
Background Water Useage (m3/hr) 1.15 1.46 0.46 0.56 1.72 5.36Consumer Losses (m3/hr) 0.14 0.38 0.27 0.16 0.45 1.40Consumer service & plumbing (m3/hr) 0.05 0.08 0.04 0.03 0.08 0.30Total 1.34 1.93 0.77 0.76 2.26 7.06
Current DRWRP Project m3/hr 12.66 7.76 8.09 7.70 0.65 36.86
DRWCP Study (includes CSL) m3/hr - 0.53 17.79 1.37 1.95 21.64
m3/Km/d 118.30 94.54 185.20 340.93 7.66 108.22
DC000102Camden Street Upper19/12/2006
Mains & Coms Leakage
Legitimate Usage & Consumer Losses
FLOW DROPS (m3/Hr)
Mains Selection – Data Assessment & Scoring
All available information considered Burst Frequency Leakage Historical Performance Operations Knowledge
Data Assessment and Scoring Applied Scoring Indicative
Solution Recommended Further Investigation Do not Progress Pressure Mgt Rehabilitation – Full or Partial Combination
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Mains Scoring – L6/07 - Appendix 5
Length[m]
2 2 1 0 0 1 0
Score 0 0.05 0.1 0 19881 0.4 1 1 19732 0.8 2 2 19583 1.2 3 3 19484 1.6 4 4 1938
5 2 5 5 1928
Weighting
(0 – 5)Material
Phy
sica
l Con
dition Soil
Cor
rosi
vity
Bur
st
Fre
quen
cy
Data (existing pipe)
Hea
d lo
ss
Impo
rtan
ce
Age
Parameters / Scores
Tot
al W
eigh
ted
Scor
e
Lea
kage
Mains Scoring – L6/07 - Appendix 5Length
[m]
2 2 1 0 0 1 0Score of 15 and above considered for rehabilitation unless non target main.
Score 0 0.05 0.1 0 19881 0.4 1 1 19732 0.8 2 2 19583 1.2 3 3 19484 1.6 4 4 1938 Phase
1€751.0
1,891
5 2 5 5 1928 Phase 2
€668.01,216
DMA Totals 6,914 TOTAL €1,419.0 3,107
DC000102 - Step 1 182 Ductile Iron 5 5 1 NA NA 1 NA 22 NA - NA No - - - Non target main
DC000102 - Step 1 713 Ferrous 5 5 4 NA NA 5 NA 29 NA €325.6 NA Yes
556 157 713
This main has a high burst frequency and this combined with pipe sample graded "condition 4", it is recommended that this main is put forward for Rehab.
DC000102 - Step 1 668 Post 85 Plastic 5 5 1 NA NA 0 NA 21 NA - NA No - - - Non target MDPE or HPPE and dates from 2002
DC000102 - Step 1 608 Other 2 5 1 NA NA 0 NA 15 NA - NA No - - - Non target main
DC000102 - Step 2 145 Ductile Iron 5 4 1 NA NA 2 NA 21 NA - NA No - - - Non target main
DC000102 - Step 2 1,182 Ferrous 5 4 5 NA NA 5 NA 28 NA €471.3 NA Yes
663 369 1,032
Pipe sample graded "Condition Grade 5" indicating urgent replacement or renovation. There is also a high burst frequency so this main was recommended for rehab.
DC000102 - Step 2 339 Post 85 Plastic 5 4 1 NA NA 0 NA 19 NA - NA No - - - Non target MOPVC from 1996 and 2002
DC000102 - Step 3 3 Ferrous 0 5 5 NA NA 5 NA 20 NA - NA No - - - Low burst frequency and a very short length of main,so this is not recommended for rehab
DC000102 - Step 3 884 Post 85 Plastic 4 5 1 NA NA 0 NA 19 NA - NA No - - - Non target main of MDPE from 2002
DC000102 - Step 4 5 Ductile Iron 0 5 1 NA NA 0 NA 11 NA - NA No - - - Non target main
DC000102 - Step 4 446 Ferrous 5 5 4 NA NA 5 NA 29 NA €203.2 NA Yes
445
-
445
Pipe sample graded "Condition Grade 5" indicating urgent replacement or renovation. There is also a high burst frequency so this main was recommended for rehab.
DC000102 - Step 4 7 Post 85 Plastic 0 5 1 NA NA 0 NA 11 NA - NA No - - - Non target main
DC000102 - Step 5 498 Ductile Iron 2 0 1 NA NA 0 NA 5 NA - NA No - - - Non target main
DC000102 - Step 5 1,148 Ferrous 5 0 3 NA NA 5 NA 18 NA €418.8 NA Yes
227 690 917
Overall score is ablove the target threshold, the Pipe sample graded "Condition Grade 5" indicating urgent replacement or renovation. This combined with a high burst frequency has resulted in the main being recommended for rehab.
DC000102 - Step 5 85 Post 85 Plastic 5 0 1 NA NA 0 NA 11 NA - NA No - - - Non target main and there has only been two leaks
Dublin Region Watermains
Rehabilitation Project -
Contract 7
Camden Street Upper
Len
gth
Mai
ns fo
r R
ehab
- P
hase
1 (m
)
Com
men
ts
Rec
omm
ende
d in
2.2
R
epor
t
Weighting
Indi
cative
pay
back
(0 – 5)Material
Phy
sica
l Con
dition Soil
Cor
rosi
vity
Bur
st
Fre
quen
cy
Scheme Name DMA name Scheme/ DMA/ Works ref.
Data (existing pipe)
Len
gth
Mai
ns fo
r R
ehab
- P
hase
2 (m
)
Len
gth
Mai
ns fo
r R
ehab
(m
)
Indi
cative
rat
ing
Hea
d lo
ss
Est
imat
ed c
ost
(€ 0
00's
)
Impo
rtan
ce
Age
Parameters / Scores
Tot
al W
eigh
ted
Scor
e
Lea
kage
Results – Skelly’s Lane
UFW SUMMARY REPORT FOR:-
65.0
65.0
69.6
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
800.0
900.0
To
tal
UF
W(m
3/d
ay)
CSL
Mains & Comms
PHASE 1
DC000109 - Skelly's Lane 468.2TOTAL TARGET UFW
(m3/day) =
POST-CONSTRUCTIONVALIDATION
Results – Crumlin Cross
UFW SUMMARY REPORT FOR:-
83.6
83.6
74.6
0.0
200.0
400.0
600.0
800.0
1000.0
1200.0
To
tal
UF
W(m
3/d
ay
)
CSL
Mains & Comms
PHASE 1
DC000028 - Crumlin Cross 828.8TOTAL TARGET UFW
(m3/day) =
POST-CONSTRUCTIONVALIDATION
Conclusions
Good Data is Key to Sound Investment Decisions Use Best Available –
Non Domestic metering Pipe Samples - Opportunistic
Improve Existing Geo-reference Burst Records Maintain GiS Maintain Telemetry Records
Optimise DMA Sizes Develop NRR Calculations
Burst Records ALC and Leakage History
Use Scoring as Guide
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Enormous Challenge Integrated Approach
Essential Ongoing Active Leakage Control Pressure Management Data Improvements and
Understanding of Components of Demand
Demand Management Sustained Asset Renewal
Mains & Services??
Rehabilitation only Part of the Solution
Conclusions
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009
Conclusions – DRWRP Results
Post 5 Contracts Total Length Rehabilitated – 51km > 4,000 New Boundary Boxes Total Savings – 7.9 Ml/day
Pipe Rehabilitation – 2.1 Ml/day Pressure Mgt. – 2.4 Ml/day DMA Optimisation/Metering – 3.4 Ml/day
Pilot DMA 100% Rehab Majority Leakage Private Side Public Network Leakage Minimal
Integrated Approach Achieving Success
Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009