Transcript Document

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/Replacement
in a Large Urban Area
Alan Curran
Technical Director
RPS Consulting Engineers
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Presentation Outline

Case Study
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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

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
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Background – Dublin Region Water Conservation Project
(Stage 1 and 2) - 1998-2002
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)
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Pilot Leakage Driven Water Mains Rehabilitation
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Confirmation that Rehabilitation Essential to
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Maintain Saving
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Reduce below 28%
2002-2006 ALC and Systems Well Maintained
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
DRWRP Drivers and Objectives
Overriding Purpose
 To Save water by Rehabilitating water mains
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Through an Integrated Approach:
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the greatest sustainable water savings,
in a cost effective manner
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
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
DRWRP Scope
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Scope:
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Up to 4% of total mains length (~ 280 km) limited by budget
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Higher rate required in long term
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New development unlikely to be targeted (separate issues)
PHASE 1
DMA Prioritisation
(5 months)
PHASE 2
PHASE 3
DMA & Mains
Appraisals &
Outline Design
(7 months)
Detailed Designs and
Construction
(5 years)
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Challenges – Urban Environment

Complexity of the Network
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Handling Large Data Sets
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8,500 km
> 600 DMA’s
55,000 leak records
Density of Services
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Understanding
Valve Density, Status and Connectivity
CSL Risk
Night Users
DMA Material and Age Mix
Construction Cost Variability
Access Issues – Traffic Management
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Challenges - Leakage
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How to Achieve Success
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Selecting the Correct
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DMA’s
Mains within the DMA’s
Accuracy of Leakage Calculations
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Which is ultimately measured at DMA Level
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
Client
GIS
Telemetry
Burst
Records
Network
Models
Stake
Holders
Leakage
Information
1. DMA Prioritisation
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Collate
& Check Data
Agree
Candidate
DMA List
Characterise
DMAs
Leakage/Cost
Analyse DMA
Leakage
Prepare DMA
Rankings
Assign Leakage
To DMA Assets
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Identify Target
Assets
LA Ranking
Sense Check
Prioritise DMA
Work Packages
Prioritise
DMAs
Produce
Strategy Report
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Ranked
DMA List
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Strategy
Report
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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
Client
GIS
Telemetry
1. Strategy Development & DMA Ranking
Burst
Records
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Network
Models
GIS
Network
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DMA Boundaries
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Geodirectory - Properties
Other Network Information
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Pressure Management
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Schematics
Telemetry
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Flow and Pressure
DMA Leakage Sheets (ESPB)
Leak Repair Records
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NRR
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Repeat Leak History
Network Models
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AZNP
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Detailed Design
Historical Rehabilitation Unit Costs
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Collate
& Check Data
Agree
Candidate
DMA List
DMAs
Leakage/Cost
Leakage
Prepare DMA
Rankings
Assign Leakage
To DMA Assets
Collate
& Check Data
Characterise
Analyse DMA
LA Ranking
Sense Check

Identify Target
Assets
Prioritise DMA
Work Packages
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Prioritise
DMAs
Produce
Strategy Report
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Ranked
DMA List
Strategy
Report
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Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Stake
Holders
Leakage
Information
DMA Ranking – Characterise DMA’s
Households & Non
households
Night Use Allowances
MNF (m3/h)
SAVINGS
NNF (m3/h)
Mains & Comm.
Pipe Leakage
Hour – Day Factor
Total Leakage
(m3/d)
CSP Leakage (m3/d)
M&C Leakage
(m3/d)
Length of mains (km)
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
M&C Leakage
m3/km/d
DMA Ranking – Characterise DMA’s
SAVINGS
Lstart
NRR
Volume of
leak repairs
[R]
NRR = Lend – Lstart + R
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Len
d
Natural Rate of
Rise in Leakage
DMA Ranking – Characterise DMA’s
COSTS
Mains
Rehabilitation
Works Costs
Technique Unit
Costs
Technique
selection
Local Roads
Policy
Reinst Unit
Cost
Stakeholders
Social
Impacts
Leak Repair
Savings
Present
Value
Additional LC /
Enabling works
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Base Unit Costs
Total Unit
Cost (€ per
m)
DMA Ranking – Characterise DMA’s
COSTS
SAVINGS
Mains
Rehabilitation
Works Costs
Mains & Comm.
Pipe Leakage
€
€ / Ml saved
- Leak Repair Cost
Savings
Natural Rate of
Rise in Leakage
DMA RANKING
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Ml
DMA Selection and Prioritisation
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8 Ranking passes carried out
Apr-July 06
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Each set reviewed LA’s –
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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
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Shortlist agreed matching DMAs
“non-responsive” to ALC
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Mains Selection - Objectives
Client
GIS
Telemetry
Burst
Records
Network
Models
Stake
Holders
Leakage
Information
2. Mains Prioritisation
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Validate/Improve Data in
Candidate DMA’s
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Field Work
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Desk Top
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Data Validation
Candidate DMA’s
Data Analysis
Mains
Scoring
Field
Assessment
Detailed Data
Verification
Solutions
DMA Integrity
Asset Data
Burst
Records
No Action
Step Testing
Leakage
Analysis &
Assignment
Rehabilitation
Meter/PRV
Audits
Other Data
Pipe Samples
Pressure
Management
Operations Staff Interview
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Leakage & Asset Data
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Detailed Analysis and Scoring
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Recommend Solution
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
DMA
Appraisal
Reports
Mains Prioritisation – Validation
Client
GIS
Telemetry
Burst
Records
Network
Models
Stake
Holders
Leakage
Information
2. Mains Prioritisation
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60 Short-listed DMAs and Reserves only
(40/20)
Data Validation
Candidate DMA’s
Data Analysis
Mains
Scoring
Field
Assessment
Detailed Data
Verification
Solutions
DMA Integrity
Asset Data
Burst
Records
No Action
Step Testing
Leakage
Analysis &
Assignment
Rehabilitation
Meter/PRV
Audits
Other Data
Pipe Samples
Pressure
Management
Integrity of the DMA’s
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Meter / PRV audits,
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BV checks,
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PZT,
Leakage Assignment
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Step-testing,
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Burst Geo-referencing and Assignement
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Operations Interview
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Data Review – Leakage, Burst History,
Customer Side Leakage Assessment
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
DMA
Appraisal
Reports
Mains Selection – DMA Integrity
Mains Selection – Assets
Mains Selection – Bursts
Mains Selection – Step Tests
STEP TEST ASSESSMENT FOR:DMA REF:DMA NAME
DATE VERIFIED:-
DC000102
Camden Street Upper
19/12/2006
Step 1
BASE DATA
No. Domestic Addresses
No. Commercial Addresses
No Buildings/Connections
Exceptional Night Use (m3/Hr)
Step 2
Step 3
Step 4
Step 5
Total
66
107
72
0.2
180
144
135
0.0
127
31
109
0.0
77
45
71
0.1
214
168
106
0.0
664
495
493
0.3
57
28
27
2
55
37
17
1
9
4
4
1
9
3
5
1
28
9
9
10
158
81
62
15
713
2,172
0
2,172
1,182
1,665
0
1,665
3
887
0
887
446
458
0
458
1,148
1,731
0
1,731
3,492
6,914
0
6,914
14.00
-
9.68
1.05
8.87
18.65
8.46
2.10
2.91
4.50
43.92
26.30
Legitimate Usage & Consumer Losses
Hour to Day Factor
20.3
20.3
20.3
20.3
20.3
20.3
Background Water Useage (m3/hr)
Consumer Losses (m3/hr)
Consumer service & plumbing (m3/hr)
Total
1.15
0.14
0.05
1.34
1.46
0.38
0.08
1.93
0.46
0.27
0.04
0.77
0.56
0.16
0.03
0.76
1.72
0.45
0.08
2.26
5.36
1.40
0.30
7.06
36.86
Bursts
Mains and Mains Fittings Leaks
Comms and Comms Fittings Leaks
Customer Supply Pipe and CSP Fittings Leaks
Length Target Mains (m)
GIS Length of Mains (m)
Length Mains Missing from GIS (m)
Total Length of Mains (m)
FLOW DROPS (m3/Hr)
Current DRWRP Project
DRWCP Study
Mains & Coms Leakage
Current DRWRP Project m3/hr
12.66
7.76
8.09
7.70
0.65
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
Mains Selection – Data Assessment
& Scoring
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All available information considered
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Data Assessment and Scoring Applied
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Burst Frequency
Leakage
Historical Performance
Operations Knowledge
Scoring Indicative
Solution Recommended
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Further Investigation
Do not Progress
Pressure Mgt
Rehabilitation – Full or Partial
Combination
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Parameters /Scores
(0 – 5)
Data (existing pipe)
Material
Burst
Frequency
Leakage
Physical
Condition
Soil
Corrosivity
Head loss
Age
Importance
Length
[m]
2
2
1
0
0
1
0
0
1
2
3
4
0.05
0.4
0.8
1.2
1.6
0.1
1
2
3
4
0
1
2
3
4
1988
1973
1958
1948
1938
5
2
5
5
1928
Weighting

Score
Total Weighted Score
Mains Scoring – L6/07 - Appendix 5
Comments
0
Length Mains for
Rehab (m)
1
Length Mains for
Rehab - Phase 2 (m)
0
Length Mains for
Rehab - Phase 1 (m)
0
Recommended in 2.2
Report
1
Indicative payback
2
Estimated cost
(€ 000's)
2
Indicative rating
Importance
Weighting 
Age
Material
Head loss
Length
[m]
Parameters /Scores
(0 – 5)
Soil
Corrosivity
Data (existing pipe)
Physical
Condition
Scheme/ DMA/
Works ref.
Leakage
DMA name
Burst
Frequency
Scheme Name
Total Weighted Score
Mains Scoring – L6/07 - Appendix 5
Score of 15 and above considered for
rehabilitation unless non target main.
Score
DMA Totals
Dublin Region
Watermains
Rehabilitation
Project Contract 7
0
1
2
3
4
0.05
0.4
0.8
1.2
1.6
0.1
1
2
3
4
0
1
2
3
4
1988
1973
1958
1948
1938
5
2
5
5
1928
Phase
1
Phase
2
6,914
€751.0
1,891
€668.0
1,216
TOTAL
€1,419.0
3,107
DC000102 - Step 1
DC000102 - Step 1
182
713
Ductile Iron
Ferrous
5
5
5
5
1
4
NA NA
NA NA
1
5
NA
NA
22
29
NA
NA
€325.6
NA
NA
No
Yes
556
157
DC000102 - Step 1
668 Post 85 Plastic
5
5
1
NA NA
0
NA
21
NA
-
NA
No
-
-
Other
Ductile Iron
Ferrous
2
5
5
5
4
4
1
1
5
NA NA
NA NA
NA NA
0
2
5
NA
NA
NA
15
21
28
NA
NA
NA
€471.3
NA
NA
NA
No
No
Yes
-
-
663
369
DC000102 - Step 2
DC000102 - Step 3
339 Post 85 Plastic
3
Ferrous
5
0
4
5
1
5
NA NA
NA NA
0
5
NA
NA
19
20
NA
NA
-
NA
NA
No
No
-
-
DC000102 - Step 3
DC000102 - Step 4
DC000102 - Step 4
884 Post 85 Plastic
5
Ductile Iron
446
Ferrous
4
0
5
5
5
5
1
1
4
NA NA
NA NA
NA NA
0
0
5
NA
NA
NA
19
11
29
NA
NA
NA
€203.2
NA
NA
NA
No
No
Yes
-
-
DC000102 - Step 4
DC000102 - Step 5
DC000102 - Step 5
7 Post 85 Plastic
498
Ductile Iron
1,148
Ferrous
0
2
5
5
0
0
1
1
3
NA NA
NA NA
NA NA
0
0
5
NA
NA
NA
11
5
18
NA
NA
NA
€418.8
NA
NA
NA
No
No
Yes
DC000102 - Step 5
85 Post 85 Plastic
5
0
1
NA NA
0
NA
11
NA
-
NA
No
DC000102 - Step 1
DC000102 - Step 2
DC000102 - Step 2
608
145
1,182
-
-
Camden Street Upper
445
-
-
227
690
-
-
- Non target main
This main has a high burst frequency and
this combined with pipe sample graded
"condition 4", it is recommended that this
713 main is put forward for Rehab.
- Non target MDPE or HPPE and dates from
2002
- Non target main
- Pipe
Non target
main
sample
graded "Condition Grade 5"
indicating urgent replacement or
renovation. There is also a high burst
frequency so this main was recommended
1,032 for rehab.
- Non target MOPVC from 1996 and 2002
- Low burst frequency and a very short length
of main,so this is not recommended for
rehab
- Non target main of MDPE from 2002
- Pipe
Non target
main
sample
graded "Condition Grade 5"
indicating urgent replacement or
renovation. There is also a high burst
frequency so this main was recommended
445 for rehab.
- Non target main
- Non target main
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
917 recommended for rehab.
- Non target main and there has only been
two leaks
Results – Skelly’s Lane
UFW SUMMARY REPORT FOR:-
CSL
Mains & Comms
DC000109 - Skelly's Lane
TOTAL TARGET UFW
(m3/day) = 468.2
900.0
800.0
65.0
Total UFW(m3/day)
700.0
600.0
65.0
500.0
400.0
69.6
300.0
200.0
100.0
0.0
PHASE 1
VALIDATION
POST-CONSTRUCTION
Results – Crumlin Cross
UFW SUMMARY REPORT FOR:-
CSL
DC000028 - Crumlin Cross
Mains & Comms
TOTAL TARGET UFW
(m3/day) = 828.8
1200.0
1000.0
Total UFW(m3/day)
83.6
83.6
800.0
600.0
400.0
74.6
200.0
0.0
PHASE 1
VALIDATION
POST-CONSTRUCTION
Conclusions


Good Data is Key to Sound Investment Decisions
Use Best Available –



Improve Existing





Geo-reference Burst Records
Maintain GiS
Maintain Telemetry Records
Optimise DMA Sizes
Develop NRR Calculations



Non Domestic metering
Pipe Samples - Opportunistic
Burst Records
ALC and Leakage History
Use Scoring as Guide
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009
Conclusions


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
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




– 2.1 Ml/day
– 2.4 Ml/day
– 3.4 Ml/day
Pilot DMA 100% Rehab



Pipe Rehabilitation
Pressure Mgt.
DMA Optimisation/Metering
Majority Leakage Private Side
Public Network Leakage Minimal
Integrated Approach Achieving Success
Meeting the Challenges of the
Changed Economic Environment
Annual Conference September 2009