7 th IWA International Conference on Efficient Use and Management of Water (Efficient 2013) Paris, France. 22-25 October 2013 Training/coaching utilities in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management Marco Fantozzi 1 *, Allan Lambert 2, Bambos Charalambous 3, Ivo Pothof 4,5, Jurica Kovac 6 1 Studio Marco Fantozzi, Via Forcella 29, 25064 Gussago (BS), Italy 2 Water Loss Research & Analysis Ltd, Llanrhos, Llandudno, Conwy LL30 1SL, UK. 3 Hydrocontrol Ltd., 196 Franklin Roosevelt Avenue, POBox 71044, CY3840, Lemesos 4 Deltares, P.O. Box 177, 2600 MH Delft, Netherlands 5 Delft University of Technology, Department of Water Management, Stevinweg 1, 2628 CN Delft, Netherlands 6 Aqua Libera Ltd.Croatia ABSTRACT *Corresponding author, e-mail: marco.fantozzi@email.it The proven benefits of pressure management in distribution systems now include not only leakage control, but also water conservation, burst reduction and Asset Management and customer service benefits. The paper will provide an overview of latest improvements in several aspects of analysis, prediction and validation of pressure management benefits. Six years ago, the publication by IWA Water Loss Task Force members of data showing significant reductions in mains and services bursts, from 112 Pressure Management Zones (PMZs) in 12 countries, helped to promote international interest in control of burst frequencies by pressure management. A conceptual explanation ( the straw that breaks the camel s back), coupled with calculation of simple separate Burst Frequency Indices (BFIs) for mains and services, has proved capable of rapidly identifying distribution zones where significant reductions in bursts could be expected, on mains and/or service connections, if pressure transients and/or excess operating pressures can be reduced. Further more recent developments include an improved prediction equation for reduction in numbers and frequencies of bursts for individual Zones, the impact of pressure management on seasonal changes in burst frequencies, and initial quantification of the financial benefits of extension of asset life. Training and coaching, including the use of specialist leakage software to facilitate and support the learning process and knowledge transfer in water utilities, are the way forward to help utilities to achieve substantial improvements in the field of water loss management. The paper summarises the recent international progress in analysis, prediction and implementation of pressure management and transient analysis to reduce bursts and extend infrastructure life and highlights the advantages of structured training and knowledge transfer on these topics.
Training/coaching utilities in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management 2 1. INTRODUCTION KEYWORDS: asset management, burst reduction, pressure management, pressure transients, training, water conservation. A major challenge facing many municipalities is how to deal with high levels of Non Revenue Water (NRW). Although not all NRW is leakage, inefficient management of distribution system pressures is known to cause substantial excess avoidable leakage and bursts, and other adverse consequences such as reduced infrastructure life. However many utilities continue to struggle with forming a convincing business case to replace and upgrade aging and inefficient distribution networks while many regulatory policies still fail to reward cost-conscious efforts to upgrade or better manage networks. Pressure management has a great potential to help improve efficiency and alleviate the impending water scarcity. In fact pressure management is now recognized as the foundation for optimal management of water supply and distribution systems. The proven benefits of pressure management in distribution systems have now moved beyond basic control of leak flow rates, as initially researched in the UK and Japan thirty years ago. Pressure management is now seen as having an increasingly wide range of benefits not only including the water conservation benefits of reducing leak flow rates and some components of consumption, but also Water Utility and customer benefits arising from reduced numbers of bursts and leaks. These include reduced repair and reinstatement costs, reduced public liability and adverse publicity, reduced costs of active leakage control, deferred infrastructure renewals and extended asset life of mains and service connections, and fewer problems on customer service connections and plumbing systems, all leading to fewer customer complaints. 2. RECENT PROGRESS ON PRESSURE MANAGEMENT STRATEGIES In 2003, the Pressure Management Team of the IWA Water Loss Task Force (now the Water Loss Specialist Group, WLSG) began to collate and publish their own research and recommendations, and encourage Utilities to present Case Studies at international Water Loss symposia. FAVAD (Fixed and Variable Area Discharges), recommended as the best practice concept for predicting pressure:leak flow relationships, is now widely used internationally. Case Studies showing reduction of bursts following pressure management were not widely known, and it was not traditional practice within Utilities to relate burst frequency to pressure, even when collecting national burst statistics for different pipe materials. Accordingly, very few practitioners believed that pressure management could influence burst frequency, other than in the control of pressure transients. This perspective started to change when Thornton and Lambert (2006, 2007) published 112 sets of data from 11 countries, showing mostly significant reductions in burst frequencies after pressure management, together with: a general explanatory concept ( the straw that breaks the camel s back and quick practical methods to identifying zones with good potential for burst reduction
Fantozzi et al. 3 on mains, or services, or both, or neither The prospect of reduction of burst repair and associated costs, and potential for improved asset management, created increased international interest in pressure management. Many hundreds of pressure management schemes have been implemented internationally since 2007, and whenever Case Studies are presented at Conferences or published, the following benefits of pressure management are now usually quoted without challenge: reduction of leak flow rates possible reduction of burst frequency on mains and on services extension of residual asset life The proven benefits of pressure management in distribution systems have now moved beyond basic control of leak flow rates, as initially researched in the UK and Japan thirty years ago. Pressure management is now recognised as having an increasingly wide range of benefits. Utilities wishing to justify pressure management need to be able make predictions of these benefits, which vary from one situation to another. The conclusions of the most recent research on understanding and predicting pressure-bursts relationships, are summarised in Lambert, Fantozzi and Thornton (2013). Some examples are shown in this paper, further details can be found in a series of papers available from www.leakssuite.com Other benefits include reduced costs of active leakage control, reductions of some components of consumption, and improved service to customers from fewer interruptions to supply. Pressure management is now being used not only for leakage control, but also for demand management, water conservation and asset management. Table 1 is the latest version of a format first used in a recent Australian Research Project (Water Services Association of Australia Asset Management Project PPS-3, 2008-11 2011) and most recently with an energy component added (Fantozzi et al, 2013) which summarises the various benefits of pressure management. Table 1: Multiple benefits of pressure management Pressure: burst frequency relationships Until quite recently, calculations of the economic case for pressure management were traditionally based only on the predicted savings from reduction of flow rates of existing leaks.
Training/coaching utilities in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management 4 Thornton and Lambert (2006, 2007) demonstrated that reduction of excess pressure in Zones with high burst frequencies could have a substantial influence on reducing bursts, and that separate predictions were needed for mains, and for services. 112 case studies in 11 countries showed an average % reduction in burst frequency of 1.4 times the % reduction in average pressure for mains. Using current and recent burst frequencies on mains (per 100 km/year) and on service connections (per 1000 services/year), it became possible to quickly predict if pressure management would reduce bursts on both mains and services, or one or the other, or neither. These simple qualitative and quantitative predictions have proved to be effective for rapidly targeting zones which would give the fastest payback for pressure management. By 2012, availability of excellent quality and quantity of data from some large Australian pressure reduction schemes, had provided an opportunity to undertake further research to develop improved predictions for the whole range of burst frequencies (Lambert, Thornton & Fantozzi 2013). Figure 1 shows that the current average burst frequencies in individual large zones may vary widely and have no unique relationship to maximum pressure at the Average Zone Point (AZP). Figure 1: Scatter plot of Average Zone Night Pressure vs. mains burst frequency for large Utility Zones Figure 2: Characteristic relationship between AZPmax and burst frequency for individual Zones (Reproduced with permission of WLRandALtd) However, if pressure management can be applied in some of these Zones, the pressure:burst frequency relationship appears to reduce asymptotically to a base level BFnpd (non-pressure dependent burst frequency) (Figure 2). The pressure-dependent burst frequency component BFpd appears to vary roughly with AZPmax3, so quite small reductions in AZPmax can produce quite large reductions in burst frequency. Figure 3 shows actual and predicted changes in repair frequency on mains in Durban Central Business District, using both prediction methods, for mixed mains materials (AC, plastic, steel, Cast Iron). Note how the seasonal variations in burst frequency are much reduced.
Fantozzi et al. 5 Figure 3: Mains repair frequencies pre- and post- pressure management, Durban CBD. (Reproduced with permission of Ethekwini Municipality). The latest equations relating pressure and burst frequency are now being used to make practical predictions of changes in burst frequency in an increasingly wide variety of countries and situations. But even larger financial benefits are likely to occur from deferred pipe renewals and extension of asset life as explained in following paragraph. Deferred Renewals and strategic prioritization and allocation of capital expenditures Significant reductions in burst frequencies on mains and services following large scale pressure management are beginning to have an influence on the numbers and choices of pipes that are renewed each year. Where Utilities have policies to replace their mains and services based on defined customer service criteria such as X bursts in Y km in Z years, some mains and services that would otherwise have been replaced are now being retained. Early indications from Australia are that financial savings arising from this can be several times the annual savings in burst repair costs. Employing dynamic pressure management tools can result in great savings on capital expenditures by strategically directing investment. A careful analysis is needed to identify those parts of a distribution system which will benefit most from pressure management and to assess the specific benefits. In this regard training and coaching in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management can make a great difference to results achieved by water utilities. 3. NEED FOR TRAINING AND COACHING Dealing with water losses or any aspect of it requires a holistic approach. So far the focus has mainly been directed towards technical issues dealing with methodologies and techniques for resolving the water loss issues, without substantial emphasis being given to the important changes required to be made in the utility with regard to capacity building in order to accomplish the desired goals. Kovac and Charalambous (2012) stipulated the additional aspects of water loss management with specific focus on coaching as a discipline, which is also applicable in the field of pressure management.
Training/coaching utilities in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management 6 It is important to understand and appreciate that besides technical knowledge regarding pressure management, other aspects or dimensions must also be considered for a successful and sustainable implementation of pressure management activities through changing existing practices. The concept of three dimensions of change was well described by Rizzo and Vermersch (2008) and involves the following: Operational dimension, Project management dimension and Change management dimension. Coping with the above mentioned changes is a serious and very complex challenge for managers in water utilities. The solutions available to this challenge are essentially provided by two approaches: implementing changes autonomously or by outsourcing necessary assistance and guidance. A key element in providing the right solution is the people within the water utilities, and without proper training, coordination and assistance, scheme selection is unlikely to achieve maximum benefits. It has been realized that change management has become a continuous condition in our world with accompanied issues like; how to design needed process, definition of goals and objectives, how to implement it, how to monitor progress and efficiency and most importantly influence on employees (resistance to change, willingness and capacity for new learning, motivation), etc. has brought to market experts with accumulated experiences from different fields of human and business activities. Current challenges Pressure management could successfully be managed through a series of comprehensive activities covering many issues such practices, methodologies, equipment, employees education, use of appropriate technology, etc. The majority of successful examples show the importance of outsourced assistance in successfully dealing with the above problems. Outsourced assistance is appropriate in most cases such as dedicated projects, specialised consultancy services and performance based projects. In addition to all the above challenges the problem of insufficient education and training programs for water utility employees must be emphasized. It is also important to highlight the fact that water utilities are often reluctant to adopt new strategies, technologies and staff is not responding to new challenges due to the public nature of the organizations. Without continuous, specific and dedicated education it only becomes more difficult for water utilities to tackle increasing number of problems in a constantly changing environment. Is training/coaching a solution? Evidently the availability of knowledge regarding pressure management to secure improvements in water utilities is not yet sufficient. Outsourcing could help but is not always easily and affordably accessible. It is therefore crucial for the successful planning and implementation of activities to improve the ability / capacity of people working in water utilities. Transfer of knowledge alone is not enough and will not guarantee that a person who
Fantozzi et al. 7 acquired this knowledge will know how to use it. There is usually a lack of practical guidance and application. The aim of practical guidance through a dedicated program of activities (training) and a close relationship between someone like a coach and employees (coaching) is to transfer virtues and knowledge. How learning works could be presented in a simplified form as follows (3): Talk to me I forget (typical example conferences and seminars). Present me I remember (typical example practical presentations). Let me do it I understand (coaching). Most important aspect of coaching is capacity building applying a specific way of teaching which is presented in a simplified form as follows: I am doing it. I am explaining it. This first step serves in presenting a new issue. You are doing it. I am explaining it. This second step is transitional with new knowledge. You are doing it. You are explaining it. Final step with transferred knowledge. Coaching / training in pressure management A coaching person can be a valuable assistant to pressure management staff. Guidance provided by a coach can help in all aspects of pressure management. He could fill in existing knowledge gap and skills with the aim to assist utilities in building their own capacities and independence over time. The authors of this paper, as well as other colleagues based in North America, Europe and Australia, use a common approach (Lambert and Fantozzi 2008) when explaining to Utility personnel how to begin to implement effective management of system pressures, as follows: Step 1: Assess probability of Pressure Management opportunities, based on type of supply (gravity or pumped), average pressure, presence of intermittent supply, etc. according to International Best Practice. Step 2: Proceed to investigations and predictions in individual sectors of a system, using best practice methodology. Step 3: Identify opportunities for achieving economic management of operating pressures, to reduce frequencies of new leaks, and flow rates of running leaks. Step 4: Select what type of pressure management is most appropriate This process is much easier to accomplish using the latest concepts, to assess probability of pressure management opportunities, to assess achievable economic benefits in individual sectors of a system and to select what type of pressure management is most appropriate. A coach can provide specific assistance in the following pressure management areas: assemble and analyse mains repairs data and service repair from different Zones to assess the potential benefit of pressure management implementation and define the priorities for intervention identify and reduce transients and surges achieve continuous supply (24/7 policy), even if at low pressure strategic sectorisation of distribution system separate transmission system from distribution system monitor pressures, flows, bursts/leaks/repairs, complaints
Training/coaching utilities in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management 8 control of service reservoir levels to avoid overflows create sub-sectors (Pressure Managed Areas or Zones) reduce pressure using intelligent pumping or fixed outlet PRVs controlled recharge of systems with intermittent supply introduce time or flow modulation for valves and pumps, etc.. Who can be a coach / trainer? Finding a coach is not an easy task. All those with excellent knowledge of Pressure Management are potential coaches, but additional knowledge and skills are needed to be able to provide appropriate coaching service. A coach must combine the following basic qualities/expertise: Pressure Management Change management General management skills Human behaviour and psychology Communication skills and motivation The knowledge gap between those who know and those who need help is huge and cooperation is necessary if fast changes in the field of pressure management are to be witnessed. Alternatively a slow process of change with many mistakes may take place with perhaps steady declining potential for improvement which could perhaps adversely affect organizational viability. Coaching / training as a discipline presents an opportunity for water utilities to improve performance as well as to build the necessary skills, capacities and efficiency among water utility managers and technicians to assist them in dealing with the field of pressure management. 4. INTEGRATED TRAINING ON PRESSURE TRANSIENTS AND PRESSURE MANAGEMENT Transient phenomena in water transportation systems (WTS) and water distribution systems (WDS) contribute to the occurrence of leaks. Transients are caused by the normal variation in the drinking water demand patterns that trigger pump operations and valve manipulations. Other transients are categorised as incidental or emergency operations. These include events like a power failure in a pumping station or an accidental pipe rupture by external forces. Focusing on normal operations, pressure transients are not only initiated by the water company via their automatic controls of pumping stations, pressure reducing valves and other equipment, but also by consumers who start and stop their water demand; especially large consumers with their own water storage tanks, like hospitals and water-using companies, may shut-off their inlet valves so fast that pressure spikes and possibly bursts are created in the distribution network. Unfortunately, operators have a limited view on pressure transients for a number of reasons. First, drinking water designers and operators have had very little education on transient
Fantozzi et al. 9 phenomena, due to the worldwide trend in middle and higher education that courses are getting broader and less specialized. A second reason for the limited view on pressure transients during normal operations is the short duration of transient events and the logging frequency of SCADA systems. The hydraulic state of a distribution network is monitored at typical time intervals of 1 or 5 minutes, which is sufficient to monitor time averaged pressures and the evolution of the flow distribution. But pressure transients rush through distribution networks at roughly 1000 m/s in steel, cast-iron, concrete and AC pipes and at 300 to 400 m/s in PVC pipes. Furthermore, the critical final stage of a valve closure takes a couple of seconds only. Therefore, transient events cannot be picked up by the normal logging frequencies of SCADA systems. The third reason is that most operators have no direct or indirect access to transient modeling tools. These transient models should be used to test whether pressure transients are responsible for frequent pipe bursts or other incidents with water losses. Therefore, operators and engineers at water utilities need continuing education on pressure transients to support their analysis and interpretation of incidents in the network and to design and improve control systems. Furthermore, they should have transient modeling tools at their disposal to support and verify the incident analyses. The need for design guidelines and education on pressure transients is not only motivated by its positive effect on water losses, but also by the contribution to safe, cost-effective and energy saving operation of water distribution systems. Despite the practical relevance, only a few references exist on guidelines for the hydraulic analysis of municipal water systems in order to reduce or counteract the adverse effects of transient pressures (Pothof 2001, Boulos 2005, Jung 2009). Only recently, Pothof and Karney (2012) have included a systematic approach for the interaction of automatic control systems with pressure transients. Since operational and incidental pressure transients are recognized as an important cause of water losses, a new course has been set-up which provides some fundamental understanding of fluid transients in relation to the operation of pumping stations, pressure reducing valves and tank inlet valves and, at the same time, provides an overview of the latest developments in pressure management strategies. The course is based on latest best practice methods developed by the Pressure Management Team of the IWA Water Loss Specialist Group, and extended experience gained by instructors with international experience. It includes lessons from practice, modeling issues, risk management, transient interaction of pumping station controls, PRVs and valve operations at large consumers. The course is geared towards anyone who deals with operation of water distribution systems, as well as the design of such systems. This includes engineers, technical and project managers and controllers of water pipeline systems and process installations who want to upgrade their understanding of pressure management and pressure transients. Further information is available at: http://www.deltares.nl/nl/cursus/1533373/advanced-course-on-pressure-management-andpressure-transients-in-water-distribu/1533375 5. CONCLUSIONS Training and coaching, including the use of specialist leakage software to facilitate and support the learning process and knowledge transfer in water utilities, are the way forward to help utilities to achieve substantial improvements in the field of water loss management.
Training/coaching utilities in practical implementation of latest developments in analysing, predicting and validating benefits of Pressure Management 10 Coaching as a discipline represents an opportunity for water utilities to improve performance by building the necessary skills, capacities and efficiency among water utility managers and technicians and by providing assistance in dealing with the multi disciplinary field of water loss and pressure management. The recent international progress in analysis, prediction and implementation of pressure management and transient analysis to reduce bursts and extend infrastructure life and highlights the advantages of structured training and knowledge transfer on these topics. Successful case studies where coaching and training supported the implementation of best practice methodologies for water loss and pressure management proved the effectiveness and convenience of this approach as it allows to: improve the ability / capacity of people working in water utilities, support the management of a water utility responsible for recognizing, understanding, defining and implementing changes and for securing improvements in water utility performances. ACKNOWLEDGEMENTS To members of the IWA Water Loss Specialist Group for their contributions to the work of the Pressure management Team. To WSAA (Australia) for permission to show Table 1 and to Water Loss Research & Analysis Ltd. for figure 2. To Ethekwini Water (South Africa) for permission to show figure 3. REFERENCES Boulos, P. F., B. W. Karney, et al. (2005). "Hydraulic transient guidelines for protecting water distribution systems." Journal / American Water Works Association 97(5): 111-124. Fantozzi M., Lambert A., (2008), Recent developments in predicting the benefits and payback periods of introducing different pressure management options into a Zone or small distribution system IWA World Water Congress, Vienna, Austria, Sep. 2008. Fantozzi M., Lambert A., Thornton, J, (2013), Practical approaches to modeling leakage and pressure management in distribution systems progress since 2005, 12th International Conference on Computing and Control for the Water Industry, CCWI2013, Perugia, Italy, Sep 2013. Jung, B. S. and B. W. Karney (2009). "Systematic surge protection for worst-case transient loadings in water distribution systems." Journal of Hydraulic Engineering 135(3): 218-223. Kovac, J., Charalambous, B., (2012), Coaching: an emerging need in Water Loss Management, IWA Water Loss Europe Conference, Ferrara, Italy, May 2012. Nelson, B., Economy, P., Le Management pour les nulls, ISBN 978-2-7540-0454-1, France 2007. Pothof, I. W. M. and G. McNulty (2001). Ground-rules proposal on pressure transients. Computing and Control for the Water Industry. Leicester, RSP Ltd, England. Pothof, I.W.M., Karney, B. (2012), Guidelines for transient analysis of supply systems, in: Water Supply System Analysis Selected Topics, Ostfeld A. (ed.), InTech OpenAccess Publisher, ISBN: 978-953-51-0889-4. http://www.intechopen.com/books/water-supply-system-analysis-selected-topics Thornton J., Lambert A., (2006). Managing pressures to reduce new break frequencies, and improve infrastructure management. IWA Water 21 Journal, December 2006. Thornton J., Lambert A., (2011). The relationships between pressure and bursts a state of the art update. IWA Water 21 Journal, April 2011 Vermersch, M., Rizzo, A., (2008), Designing an Action Plan to Control Non-Revenue Water, IWA Water21 Journal, April 2008.