Free water balance software Bulgarian version

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1 Free water balance software Bulgarian version G. Mihaylova*, M. Fantozzi*, A. Lambert**, A. Paskalev*** *Studio Fantozzi, Via Forcella 29, Gussago (BS), Italy, **ILMSS, 3 Hillview Close, Hillview Road, Llanrhos, Llandudno, Conwy Borough, LL30 1SL, UK ***Aquapartner, 58 Damyan Gruev Str., Sofia 1606, Bulgaria, aquapartner@aquapartner.com Keywords: Water Loss Management in Bulgaria; Water Balance & PI; IWA WLTF Approach Introduction Substantial advances have been made by the IWA Water Losses Task Force (WLTF) in the last few years in the development of practical water loss management methods. The IWA WLTF Approach has been implemented with success in many countries all over the world. This paper presents free software (CheckCalcs) for calculating water balance and performance indicators for Bulgarian water supply systems. The software has been customised for Bulgarian water supply terminology and language, in order to promote the practical application of the IWA WLTF Approach in Bulgaria and to improve the performance in managing water distribution systems. The paper also includes a presentation of a case study which is representative of a typical Bulgarian water system. Status of the Water Services and Leakage in Bulgaria Depending on the precipitation in a given year on the territory of Bulgaria from 9 to 24 milliards m 3 of water are produced. The average annual per capita water is about m 3. In the presence of these water resources Bulgaria ranks among the five poorest countries in water resources in Europe together with Poland, Czech Republic, Belgium and Cyprus. Although 98 % of the territory is supplied with water nearly citizens do not have 24 hours access to water in drought periods. The total number of the bigger water supply companies is 52 and most of them are public ownership. There is one concession - Sofia. The water sector in Bulgaria suffers from lack of investment over the past 15 years and the incomes of the population do not allow a significant increase in tariffs. Most of the water supply systems were constructed in the period The total length of mains in the water supply and water distribution network is kilometres, and the asbestos-cement pipes, which represent 70 percent of the network are in very bad condition. Leaks difficult to be estimated come mainly from their joints, where the rubber gasket has lost it s elasticity. Furthermore, the effectiveness of the activities was of secondary importance in the period before the changes of 1989, and this practice continued during the transition from the communism to the democracy. The combination of these factors lead to inadequate provision of services, high water losses, and environmental risks related to water quality and financial difficulties for companies. Regulatory Framework: The law of regulation of water supply and sewerage services. This Act (from ) governs regulation of prices, availability and quality of water supply and sewerage services of the operating companies for water and sewerage services. It is operated by the State Committee on Energy and Water Regulation ( The Commission ), created under the Energy Act. 1

2 Ordinance No. 1 of 5 May 2006 for ratification of the methodology for determination of admissible water losses in water supply systems The methodology is used for: status control of the water supply systems in the urban zones, analysis and valuation of the water supply systems status in the urban zones, determination of the Total Real Losses quantity in the water supply systems and of the terms of reaching of the admissible water losses. The part of the Ordinance relating to Water Balance and Real Losses starts with the basic IWA Water Balance, but then diverges from IWA recommended Performance Indicators by incorporating modified parts of German and UK practice, with some inconsistencies. This makes the application of the process complex and difficult to apply consistently. IWA WLTF methodology: Getting started, the basic approach The 4-Component diagram, shown in Figure 1, is now widely used internationally, to explain the practical concepts for managing Real Losses that are promoted by the IWA WLTF. Real Losses can be constrained and managed by an appropriate combination of all of the four management activities shown as arrows. For each system, at any particular time, there will be an Economic level of Real Losses, this usually lies somewhere between the CARL and the UARL. The three activities are Speed and Quality of Repairs, Pressure Management, and Active Leakage Control. They all tend to be more cost-effective in the short term in Euro spent/m 3 saved than pipeline and assets management, and should be considered jointly when calculating the Short Run Economic Level of Leakage (SRELL). For any distribution system, the large box represents the Current Annual Real Losses CARL (calculated from a standard IWA Water Balance, preferably with 95% confidence levels). The Unavoidable Annual Real Losses UARL are calculated from the equations developed in Lambert et al (1999), based on mains length, number of service connections, customer meter location and average pressure. The Infrastructure Leakage Index (ILI) is the non-dimensional ratio of CARL/UARL, and is the recommended best practice Performance Indicator for operational management of Real Losses. WRP (Pty) Ltd, 2001 Fig 1: Practical Management of Real Losses using the 4 Component method. 2

3 ILI benchmarks the efficiency of operational leakage management at current pressure. An ILI of 10 means that Real Losses volume is 10 times the lowest technically achievable real losses for the system at current average pressures. Let s look of some ILIs around the world in the next two figures : 50 Infrastructure Leakage Index ILI Infrastructure Leakage Index ILI Fig 2: ILIs for 22 Systems in European Developed Countries (Data from ILMSS Ltd) The IWA WLTF methodology and the basic approach can be summarised in four steps: Step A: Assess your losses and identify data deficiencies; Step B: Identify how are we doing using the most meaningful performance indicator (ILI) and the World Bank Institute Banding System; Step C: Analyse your data and start to develop your strategy and Step D: Set initial targets and get started: learn as you progress Free water balance software Bulgarian version Whilst the basic logic and principles of this approach are becoming widely accepted, potential users in Utilities, who have had their interest and expectations raised, can easily become demotivated by a lack of appropriate calculation tools to get started. Increasingly, free software is provided by IWA WLTF members for this purpose. One of these is CheckCalcs, one of the LEAKSSuite series of educational software ( designed by A. Lambert, leader of the first IWA WLTF, to assist and encourage Water Utilities everywhere to improve their leakage management performance. The softwares are designed to be easily customised and upgraded to suit specific requirements of individual Utilities, once users have become familiar with basic principles and concepts. The Bulgarian language version of CheckCalcs was created as a collaborative unfunded project by the authors of this paper, to assist Water Utilities in Bulgaria to quickly identify opportunities for saving money and saving water using the IWA best practice approach. The water balance and components of Non-Revenue water has been customised in accordance with the Bulgarian legislation, terminology, units and language. Translation from English to Bulgarian has been carried out by Gergina Mihaylova with technical support from Atanas Paskalev of AQUAPARTNER in Sofia. Most of the water balance information that is needed for the IWA best practice international water balance is already in the Bulgarian Ordinance No.1 of 5 May The two water balances use mostly the same input data, and the terms authorised and unauthorised Figure 4 shows the standard IWA water Balance In the Bulgarian CheckCalcs, the Water Balance calculation is split into two parts, in accordance with 3 Fig 3: ILIs for 33 Systems in Developing Countries (Data from WRP (pty)) ( 5 system ILIs > 50 have been omitted)

4 the National practice of separating systems into External and Internal Water Supply pipelines. Both Water Balance calculations identify metered and unmetered components. The option of entering confidence limits helps to quickly identify deficiencies in data quality and availability, but still produces a first estimate of Real Losses volume even if the raw data is of doubtful quality. Fig 4: Standard IWA water Balance Because of high consumption (and intermittent supply) in many parts of Bulgaria, % by volume is not a reliable performance indicator for analyzing problems and identifying local priorities and cost-effective solutions. The other performance indicator used in Ordinance No 1 of 5 th May 2006 m 3 /km mains/day is also unreliable for assessing and comparing performance as it is makes no allowance for losses on service connections, and is strongly influenced by density of connections, meter location, pressure and intermittent supply. In contrast, the Infrastructure Leakage Index (ILI) allows for mains length, number of service connections, system pressure, continuity of supply, and customer meter location, and so provides a fairer comparison of performance in management of Real Losses (known as Metric Benchmarking. This has now been recognized by the OVGW Austrian Benchmarking study which has tested the ILI and now recommends using it rather than %s or losses per km of mains. ILI was also used as the basis for the World Bank Institute Banding System. Using data from the Internal Water Balance, CheckCalcs calculates ILI and other traditional performance indicators (including %s, losses/service connection or losses/km mains depending upon density of connections) for NRW, Apparent Losses and Real Losses (see Fig 5), and (not shown here) also explains the limitations and appropriate circumstances for using each of them. Fig 5: Part of Performance Indicators Worksheet from CheckCalcs (Case study Vratza) 4

5 The software then allocates the ILI of the system within the WBI Banding system and identifies priorities for action according to which Band (A to D) the ILI lies within. The calculated system ILI is also compared with ILIs for the country or geographical region (in this case, for Developing Countries), as shown below in Fig. 6. Figure 6: Part of WBI Guidelines Worksheet from CheckCalcs (Case study Vratza) So, it can be seen that CheckCalcs helps the user to achieve the first 3 steps (A,B,C) of the IWA WLTF methodology described above. To achieve Step D (the most important one) is needed to make a commitment to improving the management of water losses, and realise that you will learn as you progress. Further assistance and guidance can be obtained through members of the Water Loss Task Force. These are the first steps of a continual commitment to reducing the Non-Revenue water in the Bulgarian water supply systems. Today Aquapartner become part of the increasing number of companies that progressively apply the methodology and develop a firm foundation for Non-Revenue Water reduction strategies. References Lambert A, International Report on Water Losses Management and Techniques: Report to IWA Berlin Congress, October Water Science and Technology:Water Supply Vol 2 No 4, August 2002 Brown T.G., Lambert A., Takizawa M., Weimer D, (1999). A Review of Performance Indicators for Real Losses from Water Supply Systems. AQUA, Dec ISSN Fantozzi, M., Lambert A., (July 2005) Recent advances in calculating Economic Intervention Frequency for Active Leakage Control, and implications for calculation of Economic Leakage Levels, IWA International Conference on Water Economics, Statistics and Finance Rethymno (Greece). Lambert A., Ten years experience in using the UARL formula to calculate the Infrastructure Leakage Index, IWA Conference 'Water Loss 2009', CapeTown (South Africa), April