Leakage Management in Malta. Methods used, justification and achievements to date

Transcription

1 Leakage Management in Malta Methods used, justification and achievements to date

2 Quick overview 1536 Knights of St. John The water is salty and.. In Summer the springs dry up km aqueduct from Rabat to Valletta was built by Grandmaster Alof de Wignacourt km of Galleries and 175 wells were sunk in perched and seawater aquifers

3 Dependence on Desalination The Sixties MSF Distillers The Eighties Sea Water Reverse Osmosis Plants Today blend between RO and Ground Water

4 Brief history Widespread water shortages up to Summer 93 System demand was 6,300m 3 /hr Compare this with 3,500m 3 /hr this year (around 13l/prop/hr)

5 Demand was not being met With each new RO plant commissioned, there was a corresponding increase in system demand System Demand compared with 1985 baseline 2,500,000 2,000,000 cubic metres variation 1,500,000 1,000, , ,000 Dec-85 Dec-86 Dec-87 Dec-88 Dec-89 Dec-90 Dec-91 Dec-92 Dec-93 Dec-94

6 Water Audit section Developed Determining an accurate quantification of leakage Working hands-on with staff Achieving the fine balance between the harnessing of new technologies and building a capable team of highly-skilled and motivated employees

7 Gradual Turnaround IWA Methodologies implemented Rationalisation of the network Active leakage localisation Monitoring of night flow patterns in zones (DMAs) via data loggers. The introduction of pressure management Leakage levels were 3,900m 3 /hr Target setting

8 National (Malta & Gozo) System Demand Compared to 1985 baseline Production:160,000m 3 /day ILI:10 Production:120,000m 3 /day Cubic Metre Variation ILI: Jan-94 Apr-94 Jul-94 Oct-94 Jan-95 Apr-95 Jul-95 Oct-95 Jan-96 Apr-96 Jul-96 Oct-96 Jan-97 Apr-97 Jul-97 Oct-97 Jan-98 Apr-98 Jul-98 Oct-98 Jan-99 Apr-99 Jul-99 Oct-99 Jan-00 Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 Oct-01 Jan-02 Apr-02 Jul-02 Oct-02 Production:95,000m3/day ILI:3.7

9 5 Force Leak Control Methodology Pressure Management UARL CARL

10 Status of Network today 300 zones and sub-zones (DMAs) all of which are metered and logged 19 closed loop pressure controlled variable speed drives on pumps 200 Pressure Reducing Valves

11 As leakage was further reduced, gains became more difficult National (Malta & Gozo) System Demand Compared to 1985 baseline Jan-94 Apr-94 Jul-94 Oct-94 Jan-95 Apr-95 Jul-95 Oct-95 Jan-96 Apr-96 Jul-96 Oct-96 Jan-97 Apr-97 Jul-97 Oct-97 Jan-98 Apr-98 Jul-98 Oct-98 Jan-99 Apr-99 Jul-99 Oct-99 Jan-00 Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 Oct-01 Jan-02 Apr-02 Jul-02 Oct-02 Cubic Metre Variation

12 Previous structure of the Distribution Units Manager (Operations) System Operations Water Audit Network and Consumers Mains Laying Maintenance Manager (Works)

13 Problems with old structure Conflicts between Network Operators and Water Audit Staff phenomenon common with most Water Companies Different priorities Different targets Unhealthy competition System operating differences Too many leaders

14 Why have the Regions? Complete control over all operations within the Distribution Unit Accountability Motivated staff Complex problem broken down into manageable portions Focus

15 The Regions Setup Water operations North Region Central Region South Region Water Audit System Operations Maintenance Mains Laying Network and Consumers (North Region only)

16 Coming Back on Track! ILI Malta Regions (from Sept 03) Infrastructure Leakage Index Sep-03 Nov-03 Jan-04 Mar-04 May-04 Jul-04 Sep-04 Nov-04 Jan-05 Mar-05 May-05 Jul-05 Sep-05 Nov-05

17 Tools & techniques The bottom-up balance tool nicknamed snapshot ILI GSM Step-Testers Alternative methods - Leakage Economic Intervention Model

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20 The GSM Step-Tester

21 Advantages of the Steptester Area closure time substantially reduced No hydraulic shock as system remains saturated Possible sub-step test to further reduce detection areas Detection performed same night as step test Shorter time allows for multiple step tests per night Technician gains more quality time for investigations Damage can be located within minutes

22 Economic Intervention Model A tactical planning tool for effective leakage control. Helps to predict when it is economic to intervene to locate unreported leaks and bursts. It can also be used to prioritise interventions between many zones competing for the time of the same leakage team. If the Excess Cost exceeds the Intervention Cost for many zones, this would show that not enough resources are being allocated to active leakage control.

23 Graphical display of Data ZONE: (8449) SANNAT 2 (upper) Night Cons: 1.3 l/conn/hr Present Wk: 47 Year: MNF Interventions UBL + Night Cons Median Night Flow Interventions Flow (m³/hr) Night Cons '05 08 '05 10 '05 12 '05 14 '05 16 '05 18 '05 20 '05 22 '05 24 '05 26 '05 28 '05 30 '05 32 '05 34 '05 36 '05 38 '05 40 '05 42 '05 44 '05 46 '05 48 '05 50 '05 52 '06 02 '06 04 '06 06 No of Interventions UBL + Night Consumption Night Consumption Year / Week No

24 Graphical display of Data Week to start Rate of Rise leak decreased due to intervention active leakage ZONE: (8449) SANNAT 2 (upper) control Present Wk : 47 Year: 2005 Costs (Lm) Active Leaks Cost of excess loss Interventions Excess Costs fall to zero as all economically obtainable leaks are repaired Present Week Future Trend Economic Exit Level No of Interventions, Active Leaks & Passive Leaks Historic cost of Cumulative Leakage Projected Cost of Cumulative Leakage Interventions Actice Leaks Passive Leaks 0 '05 08 '05 10 '05 12 '05 14 '05 16 '05 18 '05 20 '05 22 '05 24 '05 26 '05 28 '05 30 '05 32 '05 34 '05 36 '05 38 '05 40 '05 42 '05 44 '05 46 '05 48 '05 50 '05 52 '06 02 '06 04 ' Intervention Cost Year / Week No Linear rate of rise of leakage: 2.00 % (Default =0%)

25 Most helpful tool used... Infrastructure leakage index (ILI) 60 Production Mm 3 per annum Production

26 IWA Standard Water Balance (simplified) Water Exported System Input Volume Billed Authorised Consumption (metered and unmetered) within the Distribution System Water Supplied Non- Revenue Water Unbilled Authorised Consumption Water Losses Apparent Losses Real Losses

27 Traditional Performance Indicators for Real Losses since 1995 % of System Input per length of mains per service connection or per billed property per length of system (length of mains + services) But each gives a different perception of performance!

28 Do traditional Real Losses PI s allow for key local factors? Basic Traditional PI for Real Losses Continuity of Supply Length of mains Number of Service Connections Location of Customer meters on Services Average operating pressure % of Volume input No No No No No Litres/ property/day No No Only if 1 property/conn No No Litres/ Service Connection/Day No No Yes No No M 3 /km mains/day No Yes No No No M 3 /km of system/day No Yes Possibly Yes No Source: AQUA Paper, Dec 1999

29 Metric/process Benchmarking Metric Benchmarking compares performance between water utilities Process Benchmarking measures progress of individual water utility for setting targets, ongoing monitoring of progress towards those targets Most appropriate PI s for Process Benchmarking of NRW components: litres/connection/day m3/km mains/day Snapshot ILI ILI is the ONLY PI designed for Metric Benchmarking of Real Losses

30 One of many reasons why % s are unsuitable for Process and Metric Benchmarking

31 Some other problems with % s What were the % Water Losses in 2007 for the whole of a particular country (name omitted), as % of System Input Volume (SIV)? Method X: 6.5% Method Y: 8.9% Method Z: 11.8% Method X: SIV includes all water abstracted, + exports Method Y: SIV includes all water abstracted, no exports Method Z: SIV includes only treated water supplied

32 Metric Benchmarking using the ILI Traditional PI s for Real Losses take account of only 1 of 4 system-specific parameters Parameters affecting leakage: number of service connections location of meter relative to property line length of mains average pressure Obviously assuming that...

33 UARL is based on Background and Bursts Estimates concept for well managed infrastructure in good condition, with low burst frequencies, fast repairs

34 How does ILI take account of these key system-specific factors? Unavoidable Annual Real Losses equation (1999) Main length km UARL (litres/day) = (18 x Lm x Nc + 25 x Lp ) x P Average Pressure (metres) Number of conns. Length of private pipes (km)

35 UARL by the IWA method a Gold Standard for technical excellence in Leakage Management tells you how low you could go long-term, with major capital and revenue investments, for your system at current operating pressure Not usually economic to achieve UARL unless water is very scarce, very expensive, or both UARL is used in the calculation of the ILI, the detailed IWA system-specific performance indicator for real losses operational management

36 UARL calculation based on mains length, number of services, customer meter location and average pressure Pressure Management Management Speed Active and Quality Leakage of Repairs Control Unavoidable Annual Real Losses UARL Potentially Recoverable Real Losses Speed Active and quality of Leakage repairs Control Current Annual Real Losses CARL Pipeline and Pipe Assets Materials Management: Management: selection, Selection, installation, maintenance, Installation, Maintenance, renewal, replacement Renewal, Replacement Infrastructure Leakage Index ILI = CARL/UARL

37 Summary Mixture of technical and managerial competencies Use litres/connection/day or m 3 /km mains/day or snapshot ILI: to set targets and track progress in NRW and its components within your own Utility but not to try compare your performance with others calculate UARL if you want to see how low you can go Use ILI to compare your technical performance in real losses management with others in your own country and around the world If you want to confuse others, and yourself, use % s

38 Thanks for listening Ing. Stefan Riolo Executive Director Network infrastructure Water Services Corporation Luqa Rd, Qormi, Malta