Chapter Three

Chapter Three – NRW Control And Water Supply Distribution Rehabilitation

A. Non Revenue Water (NRW) Reduction & Control

NRW is defined as the difference between the quantity of water that leaves the treatment plants and the quantity billed to the consumers based on their metered consumption. The factors contributing to NRW are:

  • Pipe bursts and leakages (due to old pipes, poor workmanship, use of unsuitable pipes  and fittings);
  • Pilferages (illegal connections in squatter areas and other thefts of water);
  • Meter under registration (the quantity of water registered by a meter is less than the actual quantity passing through it as it ages) and
  • System maintenance and fire fighting ( system maintenance refers to flushing of pipes after repairs, washing of reservoirs, testing of hydrants and others)

For the first factor i.e. pipe bursts and leakages, water is physically lost through the system, but for other factors, water is used but no revenue is collected. The losses through leakages and bursts in mains are the principal components of NRW in Malaysia constituting about 75% of NRW.

Levels of Non-Revenue Water (NRW) in Malaysia's water supply distribution systems in the 80s were high, above 40% of production. These high levels are mainly caused by inappropriate choice of pipeline materials and insufficient attention to system maintenance and rehabilitation.


Realising the seriousness of increasing levels of NRW and the benefits of reducing it, Malaysia launched a number of NRW reduction and control programmes throughout the country from the mid 80s. The first pilot leakage control initiative using specialist equipment and adopting the "UK Rational Approach" developed in the UK by the Water Authorities Association in conjunction with WRc was carried out in Alor Setar in 1985.


Since then many more leakage control initiatives have been carried out both by Consultants and JKR.


Bina Runding was awarded a number of NRW control projects and I was the Project Director in charged. Initially, the technology of NRW reduction and control was new in Malaysia and we had to seek assistance from foreign experts, particularly from the United Kingdom. John Taylor from the UK was involved in some infrastructure projects in Malaysia in the early 80s and when NRW control projects were first launched, Bina Runding managed to team up with John Taylor (later Acer Consultant) to bid for them.


NRW Control Projects Undertaken by Bina Runding


  • Petaling Jaya NRW Control Project (1986 to 1988)

This project covers Petaling Jaya, a satellite town of Kuala Lumpur with about 250,000 population. Several thousand leaks were located and repaired and losses were reduced significantly. Meter under­registration and losses due to fire fighting, illegal connections and mains flushing were assessed and leakage levels and losses from trunk and distribution mains, reservoirs and tanks were determined.  Classroom and field training in Malaysia and oversea were provided for 20 Malaysian staff.


  • Sabak Bernam NRW Control Project (1987 to 1988)


This project covers the Sabak Bernam District with about 60,000 consumers served by over 600 km of mains. Existing losses were assessed at well over 50 percent of supply. Surveys of the levels of service provided by the system at the start and on completion of the project were carried out to evaluate improvements made. Ten waterworks staff were trained for over a year in leak detection and system operation waste prevention. Several hundred leaks were located and repaired. From the leakage control work carried out and adjustments in system operation, system pressures were substantially increased.


  • Kluang Leakage Control Project (1988 to 1990)


This project covers the whole of the Kluang district of about 3,000 sq km with a population of some 184,000 with more than half living in Kluang town itself. The project was undertaken in two phases. The first was to generate suitable data, undertake pilot studies and formulate an appropriate NRW Control Policy. The second was to implement that policy throughout the district and, in doing so, to train the local staff for its continuing operation. 


  • National Non­-Revenue Water Control study & Development of Control Programme (1988 to 1989)
  • Pandamaran Pilot Area NRW Control Demonstration Project (June to Sept 1989)



  • West Johor NRW Control Project Phase 1 (April 90 to Dec 91)




These works comprise desk studies and field surveys covering all the salient points to be considered in NRW control. Professional inputs were used on surveys and investigations backed up by substantial field flow measurements of treatment plants and interdistrict transfers, construction of a national data base, data analysis, mathematical modeling and the formulation of a national programme on a statewide and district basis. The unit costs of leakage were derived and used to assess the impact of NRW on water supply management for each of the districts and states of Malaysia.


This is part of proposal for a Management and Maintenance CONTRACT FOR nrw CONTROL IN THE state of Selangor. A demonstration project was carried out at Pandamaran, Klang. This area has over 6,000 connections with an initial leakage level of about 120 litres/connection/hr. More than 300 leaks were located and reduced to about 70 litres/connection/hr. The net benfit of leakage control was estimated at about RM54/connection/yr. At the same time, 1,000 dpmestic meters were replaced. Average meter reading of the new meters increased from 0.93 m3/connection / day to 1.53m3/connection/day. The net benefit of adopting a 6-year meter change out policy was estimated at RM32/connection/yr.


The project area covers three districts viz, Muar, Batu Pahat and Pontian with a combined total number of connections of over 115,000 serving a population of over 600,000. NRW findings and recommendations made under the National NRW Study for the project area were reviewed and verified through production flow measurements and estimation of minimum night flows through measurements and estimation of metered consumption from billing records. The costs/benefits and economics of NRW control as presented in the National NRW Study were also reviewed for the formation of NRW Control Policy for the project area.




Most of the NRW initiatives carried out by Consultants were implemented in two stages. Stage 1 consisted of detailed leakage surveys and policy determination and Stage 2 involved policy implementation and training of JKR staff to continue the programme or extend the programme to other areas after the completion of the Consultants' Stage 2 input. Most of the initiatives carried out in the various parts of the country by the JKR were generally in response to serious water supply problems in those areas. The JKRs’ NRW Control Units also initiated NRW control programmes in some districts while in some others, it assisted its district staff in setting up waste districts for them to carry on the programmes on their own.


Intensive metering is the only leakage control policy adopted in Malaysia so far. The policy entailed the identification and establishment of supply zones as waste control districts, leak location and repair and the subsequent monitoring of the established waste districts.

B. Rehabilitation of water supply distribution systems.

With the initial experience gained from all the NRW initiatives carried out, Malaysia was at the crossroads. It would be unwise to proceed with NRW reduction and control programmes in an ad hoc manner as this has not been proven to be effective. After the initial success, the NRW levels in some areas had regressed due to a lack of follow-up. It would therefore be necessary that a different approach be adopted to make the programmes more cost effective and efficient.


It had been established that besides NRW control, a systematic approach to mains rehabilitation and upgrading was essential and should form part of the overall policy for efficient operations and maintenance of water supply distribution systems. This had subsequently prompted JKR to initiate NRW control projects to include rehabilitation and upgrading of the distribution systems. The shift in the implementation strategy was most appropriate as the operation of a water supply distribution system at optimum NRW levels does not only consist of measures to reduce leakage but also long-term maintenance which requires strategic planning of investments to rehabilitate parts of the distribution system as they are approaching the end of their economic working life.


In view of the above Bina Runding was awarded a project to be carried on this basis.


NRW Control, Rehabilitation and Improvement of Distribution Systems for Perlis (1990-1992)


Bina Runding was appointed to carry out the study as part of the overall programme to rehabilitate and upgrade the water distribution system including the development of an underground assets management plan for the State of Perlis. A review and verification of the findings and recommendations made under the National NRW Study relevant to Perlis were also included.


Pipe condition survey of the distribution system was conducted to evaluate the structural condition and hydraulic performance of the existing pipeworks for the formulation of an Underground Assets Management Plan (AMP) to ensure a more systematic approach in the maintenance of the existing underground assets and subsequent mains rehabilitation/upgrading and NRW control.


A computer network model was developed to determine the adequacy of the existing distribution system. New mains to cater for the expected increase in the future demand were also planned.


However, due to the finance and other constraints, only NRW control programmes were implemented.

In 1992, the Asian Development Bank financed a study of rehabilitation and upgrading requirements of existing water treanment plants and distribution systems in 32 districts in Peninsular Malaysia. The objectives were to achieve a high level of performance from the existing systems and to systematically reduce NRW from the natioanal average estimated at 43% in1998 to less than 20% by year 2000.



Though NRW Reduction and Control programmes have been introduced in Malaysia for over two decades, leakage levels in many areas still remain high. Table below shows the NRW levels (abstracts from “Water Malaysia”) published by Malaysian Water Association.




































































N. Sembilan


















National average






The State of Penang has consistently the best and lowest NRW level in Malaysia. It is the only State that had achieved the national NRW target of 29% in year 2000. The States that require immediate focusing on NRW reduction and distribution rehabilitation are Perlis, Pahang, N. Sembilan, Kelantan and Sabah where the NRW levels far exceed the national average.


It is uneconomical and impractical to construct and maintain a leak-free distribution system. However loss through leakage can be controlled to certain extent by using appropriate pipeline material and having adequate distribution operation and maintenance.


Malaysia is fortunate in that we do not have to formulate the technical approach to NRW on our own. In the UK, the first serious attempt to address the problem of leakage started in the early 80s when the Water Authorities Association in conjunction with Water Research Centre published the "Leakage Control Policy and Practice", commonly known as Technical Report 26 or TR 26. The methodology in TR 26 or the "UK Rational Approach" is simple and generally applicable to virtually any system in the World. It is called a "Rational" approach because it is a logical procedure for measuring the leakage in different parts of the system, determining the cost of the water lost, and comparing it with the appropriate methods of leakage control.


In most of the leakage control projects in Malaysia, the "UK Rational Approach" had been adopted. All projects using this approach had been successfully completed. This showed that the approach was generally applicable in Malaysia.


However, it is to be noted that there are some important and fundamental differences between the UK and Malaysia water supply systems and therefore, some modifications to the "UK Rational Approach" would be necessary to make it more effective, practical and relevant under the Malaysian conditions.


In the UK where all the distribution mains are of metallic (CI, DI and Steel) and MDPE materials and where all underground assets are well mapped on GIS systems allowing efficiency in operational management and maintenance, it is expected that the intrinsic leakage levels of their systems are low in comparison with those of Malaysian systems. Fig. 5.1 extracted from TR 26 shows the intrinsic leakage levels of large urban UK distribution systems. This graph has often been used to predict the target leakage levels for NRW control projects in Malaysia and for economic analysis in determining the appropriate leakage control policy.


In Malaysia where leakage control programmes are carried out in both urban and rural areas and where pipeline materials in use are predominantly AC. Fig. 5.1 will no longer be applicable.


Fig 5.1 – Intrinsic leakage Levels In large Urban Areas In UK

There were some research and development initiated by the Leakage Control Steering Group of the Water Services Association and the Water Companies Association in the UK to modify TR 26 for application in rural areas. The methodology developed to modify TR 26 uses a '2-part formulae' which sets leakage targets that could be applicable to any large areas, whether urban or rural.


The methodology adopted in this '2-part formulae' assumes 'Main Length per Property' (MLP) as the prime factor in determining the intrinsic levels of leakage in the distribution systems. The other factor being the inherent characteristics of the distribution systems i.e. pipe material, age and level of workmanship and maintenance.


Using this '2-part formulae' the achievable leakage level curve for each country can be constructed. However, the appropriateness of this approach depends to a large extent on the quality of data available. In Malaysia, though a number of leakage control projects have been carried out, little information is available on the sustainable targets of leakage levels in areas where NRW reduction and control programmes have been implemented. This is due to the lack of sustained efforts by the water authorities in pursuing leakage control programmes after they have been initiated.


In spite of the above, limited data is available on reduced scale in areas where Bina Runding were involved in assisting the various water authorities in the setting up of waste control districts. These areas include Petaling Jaya, Kluang, Pedis, Muar, Batu Pahat and Pontian. Pelaling Jaya and Kluang are predominantly urban areas with MLP of about 10m. Muar and Batu Pahat are semi-urban with MLP of about 25m, while PerIis and Pontian are rural with MLP of over 40m.


Using the data obtained from the above districts, the leakage improvement graph could be plotted upon the completion of the Consultants' work in establishing waste control districts and locating and repairing leaks. This is shown in Fig. 5.2. Using this graph, the provisional target level of leakage of any district in Malaysia may be determined.


Fig 5.2 – Provisional Target Levels Of System Leakage from Leakage And Rehabilitation Programmes


Setting a realistic and achievable NRW target is an important mission statement in the implementation of an NRW control programme. A low target would give opportunity for people fooling themselves or leading the District Water Engineer to inappropriate action. On the other hand, too high an NRW target would be difficult to achieve and the staff involved would soon lose their interest in the project. Furthermore, NRW reduction is subject to the law of diminishing returns. It would be relatively cheap to reduce the initiate 10% of the NRW but the last 10% would be prohibitively expensive if the target set is too high.


Another major feature of TR 26 is the derivation of the Unit Cost of Leakage (UCL) which is a measure of the saving in cost brought about by reducing the amount of leakage within the system. This saving in cost consists of two elements, namely a reduction in marginal annual operating cost and a deferment of demand-related schemes resulting in a reduction in the programmed capital expenditure.

The marginal value of water lost through leakage is low as this takes into account the cost of electricity and chemicals only. This is based on the assumption that water saved would only result in a reduction in the throughput of a plant while other operating and maintenance costs would not change. However, if the amount of water saved through leakage control is big enough for a treatment plant to be taken out of operation, then it would be more relevant to consider the total operating cost of running a plant which would include staff cost and overheads.


The use of UCL as defined in TR 26 may be applicable when the current water demand does not exceed the existing production capacity whereby the water saved does not affect the present consumption but rather reduce water production. However, this is not always the case in Malaysia. Water demands in many areas have not been satisfied and many people have not been served with potable water. A case can thus be made that water saved through leakage will be made available to and used by the present or new consumers. Therefore in Malaysia, the calculation of UCL should take into account total operation and maintenance costs which should also include replacement/renewal costs.


It is important that the 'real' cost of leakage be calculated for each State/District if it is required to seek and justify a special project budget to finance an NRW control programme in the State/District.


The operation of a water supply distribution system at optimum NRW level does not consist only of measures to reduce or control leakage. Long term maintenance of the system is necessary and strategic planning of investments to rehabilitate parts of the distribution systems which are approaching the end of their economic working life is essential.


Prior to the National NRW Study, most of the NRW control projects carried out had concentrated primarily on leakage control and revenue meter replacement. The National NRW Study found that the strategy planning for a system, particularly that involving pipe rehabilitation and mains renewal, had so far not formed part of underground assets maintenance policy in Malaysia.


Furthermore NRW control techniques carried out in Malaysia concentrated on locating and repairing leaks. Unfortunately this practice is inadequate to deal with many stretches of problematic pipelines which require frequent repair.


Another common problem in Malaysia is the intermittent supplies and low pressures caused by a combination of insufficient water production, inadequate system capacity and deficiencies in the supply system. Under these circumstances, it would be difficult to set up waste zones as metering results would be unreliable and normal leakage control techniques using sounding rendered ineffective.


It is essential that an Underground Assets Management Plan (AMP) should first be drawn up to guide the subsequent mains rehabilitation/upgrading and NRW control in an overall policy for the efficient operation and maintenance of the water distribution systems. This should include pipe condition survey to identify the causes of pipe failures and to develop mains rehabilitation programmes to ensure a more systematic approach in maintaining the existing underground assets.


However, both mains rehabilitation and NRW control should be designed to be implemented in tandem. Implementing one without the other would not be effective and this has been clearly demonstrated in the State of Perlis, West Johor and Johor Bahru districts.


Investigations have shown that many NRW control programmes have failed or that their outcomes have not been to expectation. The reasons are many but the most significant ones are of institutional structure and management. Many state water departments like to pay lip-service to NRW control. They view NRW control as something 'nice' to have and would not hesitate to start on the programme even though the resource requirements have not been defined and the organisational structure has not been adjusted to properly accommodate the NRW control functions. A worse situation is where one knows the problems and has some idea of what is to be done, but somehow nothing is pursued in earnest and so the problem of NR W worsens.


There is a" general lack of resources and cohesive national and statewide policies in tackling NRW in Malaysia. While most of the states in Malaysia have embarked on some NRW control activities, the lack of targeted policy and resources has frustrated management attempts to implement effective long term NRW control programmes throughout the particular state. 


NRW control is a long term programme. Its success and effectiveness are dependent on available resources to sustain the programme. Effective long-term NRW control programme is also essential to ensure maximum financial returns on the investment made by the water authorities through their capital works programmes. It is therefore important that appropriate adjustments to the present organisational structures at both the State and District levels be made to accommodate of the NRW control functions.


The lack of improvement or even the worsening of NRW in many of the NRW control programmes in Malaysia is mainly due to the lack of follow-up by the district water departments. The State should therefore ensure that no NRW control programmes are to commence in any district where adequate manpower and financial resources have not been made available.


The manpower resources required would include various levels of management, operational and administrative staff. In the past JKR had to overcome many constraints to ensure that the development of an overall manpower strategy for NRW control programmes could proceed smoothly. The principal constraints are summarised below:


  • present practice of transferring the NRW staff to other section of the water department when they have already been properly trained in NRW control and practice.
  • Inability of some of the states to finance the recruitment of necessary staff.
  • staff are required to work under unsocial hours. The conditions of employment and incentive payments are important in retaining dedicated staff.


Besides manpower and financial resources, thorough training of the staff on all the essential NRW aspects is essential to the successful implementation of the NRW control programmes. The staff should also be fully conversant with the use of all the equipment. In the past, training on NRW control had been through the various NR W studies carried out by the States and this included both on-the-job and overseas training. Though the present water supply sector's training activities at Bangi cover the full spectrum of water supply engineering including system leakage, there is still no full-time lecturing staff at the Bangi Training Centre to deal with the specialised training on NRW control and practices.


One approach which could overcome some of the constraints faced by the government is to allow the private sector to undertake mains rehabilitation and NRW reduction and control using the latter's own finance and manpower resources. This is a form of privatisation where a Water Authority contracts out the services of NRW control and mains rehabilitation. This would enable the Water Authority to hive off the responsibility of carrying out distribution system improvement to a contractor by granting him of an Operation and Maintenance Contract. An agreement could be made between the parties whereby the services provided by the contractor would be paid for from the additional revenue generated and the savings obtained through NRW control with a nett financial benefit to the Water Authority. In essence, the contractor is paid based on performance and results.


The benefits to the Water Authority in adopting this method of equitable sharing of increased revenue and savings can be summarised as follows:


  • The project can be initiated rapidly - no restructuring of the Water Authority is required.
  • The components of the project concern new technology and techniques and so are an adjunct to the existing Water Authority's duties. To give these tasks to a contractor will therefore imply no disruption or redundancies with the existing organisation.
  • In the event of corporatisation or privatisation of the Water Authority, the specialist services being offered could remain equally valid and worthwhile to the new form of undertaking.
  • The project will pay for itself and bring increased revenue and saving to the Water Authority. In addition, it improves the standard of service to the consumers.
  • The scope of the project provides a base on which other tasks could be added in the future if desired, e.g. revenue billing and collection.
  • It allows the contractor to take over the 'headache' area of operation and maintenance and enables the Water Authority to concentrate on water supply and planning.

This privatized option offers the best option for speedy progress with no additional cost to the Water Authority, whilst leaving flexibility to adapt to future policy decisions. Currently some states in Malaysia have adopted this privatized option for NRW Control and distribution rehabilitation.

End of Chapter 3

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