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Water Services Training Group

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

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Water Services Training Group

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  1. Water Services Training Group 13th Annual Conference 10th September 2009

  2. Prioritising Mains for Rehabilitation/Replacementin a Large Urban Area Alan Curran Technical Director RPS Consulting Engineers

  3. 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

  4. 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

  5. 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) • Pilot Leakage Driven Water Mains Rehabilitation • Confirmation that Rehabilitation Essential to • Maintain Saving • Reduce below 28% 2002-2006 ALC and Systems Well Maintained Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  6. DRWRP Drivers and Objectives Overriding Purpose • To Save water byRehabilitating 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 Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  7. DMA Prioritisation (5 months) PHASE1 DMA & Mains Appraisals & Outline Design (7 months) PHASE 2 Detailed Designs and Construction (5 years) PHASE 3 DRWRP Scope • 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) Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  8. 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 Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  9. 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

  10. Client GIS Telemetry Burst Records Network Models Stake Holders Leakage Information DMA Prioritisation - Objectives 1. DMA Prioritisation • 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 Collate & Check Data Agree Candidate DMA List Characterise DMAs Leakage/Cost Analyse DMA Leakage Prepare DMA Rankings Assign Leakage To DMA Assets Identify Target Assets LA Ranking Sense Check Prioritise DMA Work Packages Prioritise DMAs Produce Strategy Report Ranked DMA List Strategy Report Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  11. Client GIS Telemetry Burst Records Network Models Stake Holders Leakage Information Collate & Check Data Agree Candidate DMA List Characterise DMAs Leakage/Cost Analyse DMA Leakage Prepare DMA Rankings Assign Leakage To DMA Assets Identify Target Assets LA Ranking Sense Check Prioritise DMA Work Packages Prioritise DMAs Produce Strategy Report Ranked DMA List Strategy Report DMA Prioritisation – Data 1. Strategy Development & DMA Ranking • 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 Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  12. Households & Non households MNF (m3/h) Night Use Allowances NNF (m3/h) Total Leakage (m3/d) Hour – Day Factor M&C Leakage (m3/d) CSP Leakage (m3/d) M&C Leakage m3/km/d Length of mains (km) DMA Ranking – Characterise DMA’s SAVINGS Mains & Comm. Pipe Leakage Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  13. Lstart NRR Volume of leak repairs [R] Lend NRR = Lend – Lstart + R DMA Ranking – Characterise DMA’s SAVINGS Natural Rate of Rise in Leakage Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  14. Technique Unit Costs Technique selection Base Unit Costs Reinst Unit Cost Local Roads Policy Social Impacts Stakeholders Present Value Leak Repair Savings Total Unit Cost (€ per m) Additional LC / Enabling works DMA Ranking – Characterise DMA’s COSTS Mains Rehabilitation Works Costs Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  15. DMA Ranking – Characterise DMA’s COSTS SAVINGS Mains & Comm. Pipe Leakage Mains Rehabilitation Works Costs € / Ml saved € Ml • Leak Repair Cost • Savings Natural Rate of Rise in Leakage DMA RANKING Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  16. 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

  17. Client GIS Telemetry Burst Records 2. Mains Prioritisation Network Models Stake Holders Leakage Information Mains Scoring Data Validation Candidate DMA’s Data Analysis Field Assessment Detailed Data Verification Solutions DMA Integrity Asset Data Burst Records No Action Leakage Analysis & Assignment Rehabilitation Step Testing Other Data Pipe Samples Pressure Management Meter/PRV Audits DMA Appraisal Reports Mains Selection - Objectives • Validate/Improve Data in Candidate DMA’s • Field Work • Desk Top • Operations Staff Interview • Leakage & Asset Data • Detailed Analysis and Scoring • Recommend Solution Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  18. Client GIS Telemetry Burst Records 2. Mains Prioritisation Network Models Stake Holders Leakage Information Mains Scoring Data Validation Candidate DMA’s Data Analysis Field Assessment Detailed Data Verification Solutions DMA Integrity Asset Data Burst Records No Action Leakage Analysis & Assignment Rehabilitation Step Testing Other Data Pipe Samples Pressure Management Meter/PRV Audits DMA Appraisal Reports Mains Prioritisation – Validation • 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 Meeting the Challenges of the Changed Economic Environment Annual Conference September 2009

  19. Mains Selection – DMA Integrity

  20. Mains Selection – Assets

  21. Mains Selection – Bursts

  22. Mains Selection – Step Tests

  23. 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

  24. Mains Scoring – L6/07 - Appendix 5

  25. Mains Scoring – L6/07 - Appendix 5

  26. UFW SUMMARY REPORT FOR:- CSL TOTAL TARGET UFW Mains & Comms DC000109 - Skelly's Lane 468.2 (m3/day) = 900.0 800.0 65.0 700.0 600.0 65.0 500.0 Total UFW(m3/day) 400.0 69.6 300.0 200.0 100.0 0.0 PHASE 1 VALIDATION POST-CONSTRUCTION Results – Skelly’s Lane

  27. UFW SUMMARY REPORT FOR:- CSL TOTAL TARGET UFW DC000028 - Crumlin Cross Mains & Comms 828.8 (m3/day) = 1200.0 1000.0 83.6 83.6 800.0 600.0 Total UFW(m3/day) 400.0 74.6 200.0 0.0 VALIDATION POST-CONSTRUCTION PHASE 1 Results – Crumlin Cross

  28. 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

  29. 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

  30. 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

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