Non Revenue Water (NRW) Management Strategy for Surabaya Water Company

Transcription

1 THE WORLD BANK PDAM Surabaya Non Revenue Water (NRW) Management Strategy for Surabaya Water Company Final Report May 2011 Prepared by : Ranhill Water Services Sdn.

2 Prepared by : Ranhill Water Services Sdn. Bhd. Head Office: Level 13, Wisma PERKESO Kuala Lumpur Malaysia Tel: Fax: Operation office: Level 4, Matang Building 83, Jalan Langkasuka Johor Bahru Johor, Malaysia Tel: Fax: Ranhill Water Services has prepared this report in accordance with the instructions of their client, for their sole and specific use. Any other persons who use any information contained herein do so at their own risk. Ranhill Water Services 31 st May 2011

3 Contents Introduction... 1 Background of the Task... 1 Task Objectives Introduction Proposed Implementation Strategy NRW Awareness Programs Production Metering Customer Metering Reservoir Overflow Control Inter-Zone Metering DMA Establishment Leakage Reduction Activities Pressure Management Establishment of Control Room Call Centre Improvement Asset Maintenance Strategic Plan Recording of Operational Usage Pipe Replacement Programme Staffing Customer Charter Financial Option Estimated Cost Options for Implementing the Proposed Strategy for NRW Management Cost Benefit Analysis Conclusion... 53

4 Introduction Ranhill Water Services Sdn Bhd (RWS) are pleased to submit the FINAL REPORT for Task 4 Preparation & Presentation of NRW management options, to the World Bank for the contract Non Revenue Water (NRW) Management Strategy for Surabaya Water Company. On the 6 th September 2010, RWS was awarded a contract to develop a Non Revenue Water (NRW) Management Strategy for Surabaya Water Company in East Java, Indonesia by the World Bank. This contract is for a period of 34 weeks commencing from 6 th September 2010 until 30 th April 2011, with the expected outcome is the delivery of a strategy for the management contract of NRW across the city, which can be used by PDAM Surabaya as a template for future investments and development. This document details RWS s Activities to the World Bank / PDAM Surabaya to complete the said works. Background of the Task Based on the results of the assessment of components for water loss in Surabaya city, review of PDAM Surabaya s current water loss management practices and system features and establishment of DMAs for pilot study purposes in Surabaya City, a Non Revenue Water (NRW) Management Strategy will be prepared for the entire city. This strategy will include the implementation strategy to deliver the proposed network management and holistic NRW management program, NRW management options and recommendations, to further improve Surabaya city s NRW situation. For this task report, RWS aims to create a best practice document report, detailing the most suitable and efficient means of undertaking an NRW management strategy for the city of Surabaya. This task report will also ensure that all components of NRW are covered and that the proposed strategy is feasible in terms of physical application and financial requirements. Task Objectives The objective of Task 4 Preparation & Presentation of NRW management options is to: Propose an Implementation strategy to deliver the proposed network management and holistic NRW management programme. Prepare NRW management options and recommendations feasible in terms of physical application and financial requirements to further improve Surabaya city s NRW situation Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 1

5 To create a best practice document report detailing the most suitable and efficient means of undertaking an NRW management strategy for the city of Surabaya. Task 4 - Preparation & Presentation of NRW Management Options 1 Introduction Proposed Implementation Strategy The following strategies, comprising 15 main activities, are recommended for PDAM Surabaya to undertake network management and holistic NRW management program: NRW Awareness Programs Production Meter Accuracy Customer Metering Reservoir Overflow Control Inter-Zone Metering DMA Establishment Leakage Reduction Activities Pressure Management Establishment of Control Room Call Center Improvement Asset Maintenance Recording of Operational Usage Pipe Replacement Programme Staffing Customer Charter 1.1 NRW Awareness Programs Many water companies that embark on NRW reduction management tend to create a dedicated NRW team with varying responsibilities. Some concentrate mainly on leakage detection, whilst others may undertake additional activities aimed at managing other NRW components. Unfortunately the setting up of these dedicated teams can sometimes have an unintended negative effect. This is mainly due to the remaining water company staff feeling that NRW is the sole problem of the NRW team and therefore mitigating any responsibility they have to helping with managing the NRW levels. In reality NRW is a company wide responsibility, with each member of the organization having a role to play in reducing NRW. Whether it s the meter reader, who should read all his meters within a set time period while on the look out for any anomalies with the meters, or the procurement executive, who is responsible for ensuring that all contracts, materials and equipments arrive expediently and of the correct quality, or all other staff within the organization who all have significant roles to play. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 2

6 To overcome the above pitfall, an NRW awareness program is proposed to be conducted to instill the basic knowledge on NRW, importance of NRW to the water company and appreciation of the benefits of NRW reduction and savings to long-time employees of the water company, as well as new joiners. The awareness sessions will impart to every personnel his or her roles and responsibilities toward achieving the reduction in NRW level. The proposed staff awareness programs are aimed at all PDAM Surabaya staff and are suggested to follow the following schedules. Each session will be conducted in a small group to ensure the contents of the program will be effectively delivered. It is also suggested that the awareness sessions be conducted according to levels of understanding to ensure that the information is well disseminated to all employees. The awareness sessions will be conducted separately according to the following sectors within the PDAM organization: Top Management and Senior Personnel Engineers and Executives Technicians and Clerical Staff Laborers, Field Assistants and Meter Readers These awareness sessions will take at least a full day for Managers and Executives and a half day for the other employees. The sessions are recommended to be conducted outside of PDAM Surabaya premises to ensure undivided attention is given by the staff involved. 1.2 Production Metering The accurate measurement of the production volume is an essential part of the calculation of NRW. Accurate meters have been installed on all of the water treatment plant outlets but not all of these meters are being verified / validated annually to ensure they are maintaining their accuracy. During the Production Meter verification exercise in Task 1, 6 meters were found to physically not satisfy the minimum required distances (10D upstream, 5D downstream) from the nearest obstruction which resulted to inaccurate readings due to disturbance of their flow regime. The Production Meter verification results also showed that 10 meters are outside the manufacturer specification for accuracy range. The results showed that these 10 meters range from (-) 6.4% up to (+) 93.0%. Most of these production meters in Surabaya are of Electromagnetic insertion probes type. Based from the results of Production Meter verification exercise, it is recommended to replace all probe insertion meters with full- bore fixflanged electromagnetic meters which have four flow sensors attached inside the meter body. The full- bore fix-flanged electromagnetic meters have the following advantages compared to probe insertion meters: Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 3

7 The installation of the full- bore fix- flanged electromagnetic meters does not affect the sensor which captures the flow readings. For probe insertion meters, the accuracy can be affected by the installation of the probe and location of sensor (1/2 or 1/8 of the pipe s internal diameter, horizontal or vertical position). Below shows the typical diagrams of probe insertion meters and full- bore fix- flanged electromagnetic meters installation: If the installation of the probe is not completed properly, for example through inaccurate data relating to the pipe, such as thickness of Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 4

8 cement lining or actual diameter, the accuracy of the flowmeter will significantly decrease. Electromagnetic fix flanged type meters accuracy range is (+/-) 0.5% compared to probe insertion meters % when installation is done properly. No moving parts and less maintenance It is also recommended that works be carried out to verify the accuracy of all production meters periodically. Methods for verification and validation of production meters need to be established to ensure that all production meters are reading correctly. For longer-term recommendation, it is suggested that PDAM Surabaya undertake meter verification on yearly basis for all production meters using a portable ultrasonic clamp-on meter. This type of flowmeter is good for flow surveying and verification purposes; however this is not recommended for permanent installations. The portable ultrasonic clampon meter is to be wet-tested as accurate at a known test site. 1.3 Customer Metering Customer Tagging and Survey NRW is a comparison between production volume and customer billing. Therefore the accurate measurement through customer surveys, and subsequent billing of customer consumption, is essential in measuring and ultimately controlling NRW. These customer surveys will involve a team of surveyors walking the designated DMA, interviewing and surveying all properties within. Standard survey forms will be utilized in the survey. Among the items that will be investigated during the survey are: Type of properties Activities of properties Meter availability Meter registration Meter condition Illegal connections Meter tampering These surveys will enable PDAM Surabaya to identify customers that are inside their designated DMAs, faulty customer meters, illegal connections, wrongly sized customer meters, tampered meters and possible new customers. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 5

9 The next step after conducting Customer tagging and surveying is to undertake a study of the existing customer meters. The customer meters must be tagged according to model, size, period of service (age of meter) and location (name and address of the customer). This information should be presented in tabulated form such as the example shown below: No. 1 Customer Name Customer Information Customer Identification Number Street Meter Model Meter Information Meter Type Meter Size Period of Services Customer Meter Accuracy Test Customer meter accuracy testing can be performed on-site at the customer premise or at a testing facility. When testing a meter on-site, the methodology is to compare the accuracy of the meter being tested with a calibrated meter tester used in the process. Meter accuracy tests conducted at a test facility usually offer better validated results since the volume of water passing through the meter (s) being tested flows into a tank of known volume. Therefore the test process is well calibrated, since the volume passed through the meter is known precisely. Below is a photograph showing a typical water meter test bench for customer meter accuracy testing: Random selection of meters according to model, size, period in service and location will be returned to the meter workshop for accuracy testing. Customer meters that are suspected to be inaccurate during customer surveys will also be subjected to an accuracy test. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 6

10 Large customers will be randomly tested on-site using temporary ultrasonic clamp-on meters suitable for small sized pipes (4-6 inchdiameter). Based on the results of the accuracy test, average meter inaccuracy values (as % of metered consumption) will be established for different user groups. Techniques for performing the test, selecting the appropriate test flow rates, determining the accuracies, and reaching conclusions must be known and carefully followed to obtain valid test results. For positive displacement meters, which are typically the small residential meters, the AWWA M6 publication provides the three flow rates (low, mid, and high), which apply to all brands. For turbine and propeller meters, which are used in large meter applications; either M6 publication or the manufacturer s meter literature must be consulted. Below is the table showing recommended test flow rates: Meter accuracy Water meters can be damaged and deteriorate with age, thus producing inaccurate readings. Inaccurate readings will give misleading information regarding water usage, make leak detection difficult, and result in lost revenue for the system. All meters, especially older meters, should be tested for accuracy on a regular basis. The system also should determine that meters are appropriately sized. Meters that are too large for a customer s level of use will tend to underregister water use. Meters should be able to accurately record the full range of expected flow rates. Establishment of a Customer Metering Management Plan This section provides a roadmap for PDAM Surabaya in planning, implementing, operating, and managing a metering plan to account for use and loss in the water distribution system. This will also provide key considerations to help PDAM Surabaya assess their priorities in developing a meter management strategy. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 7

11 In addition to addressing the management of existing customer meters, some percentage of new batches of meters supplied by supplier to PDAM Surabaya are recommended to be tested for accuracy before being allowed to be installed on customer premises. Small Residential Meters With the existing water meter testing facility, PDAM Surabaya can randomly select more customer meters according to model, size, period in service and location to be returned to a meter test facility for accuracy testing. The meters that have been taken out of service and brought to the water meter testing facility will be replaced with the new ones that have been factory tested and certified for accuracy. To maintain the accuracy of the meters in service, a dynamic meter replacement programme is also recommended whereby meters in residential premises are replaced based from the results of customer meter testing activities. The implementation of customer meter accuracy testing will also help to develop an optimum lifespan based on meter age, extent of usage and type of the customer meters prior to their replacement. It is recommended that a stopcock before a customer meter for new installations be located on the area accessible to meter readers and leakage detection teams. This will enable the meter readers to access and make proper readings of the customer meters. For the leakage teams, the stopcock before the meter can be utilized to sound for any underground leak noise occurrence. It is strongly recommended that these be implemented for new installations and during a meter replacement program whilst for the other existing meters be replaced gradually. Large Customer Meters Proper selection and maintenance of this large customer meters is essential due to its potentially large impact on PDAM Surabaya s revenue. A Large Customer Meter is defined in this report as any meter with a line size of 38mm (1.5 ) or greater typically Industrial, Commercial and Institutional users. Evaluating Maintenance and Testing Program for Large Customer Meters The following items are to be considered when evaluating a Maintenance and Testing Program Volume: Large volumes of water = large revenues Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 8

12 Servicing: Large meters should be serviced at a minimum every 6 months, Age: Large meters should be tested at a minimum every 5 years, Water Quality: Zones with harsher water conditions should consider increasing frequency of meter maintenance Higher priority old and large meters More frequent tests an error in the registration has a greater effect on equity, utility credibility, and revenue issues Desirable to test in-situ (problems with meter setting or installation that could affect accuracy are quickly identified) Large Customer Meter Replacement Customers consuming large volume of water should be ranked as Top customers. PDAM Surabaya can determine the numbers of Top Customer to be monitored closely. It is very important that these customers are monitored and measured as accurately as possible since they will have the biggest impact to NRW and revenue to PDAM Surabaya. The full- bore fix- flanged electromagnetic meters are considered the most accurate at present as they contain no moving parts, which can fail over time, have less maintenance, are not affected by water quality and they can record at much lower flow rates as compared to mechanical equivalents. RWS is therefore recommending that the top customers within PDAM Surabaya have their large customer meter s replaced with full- bore fixflanged electromagnetic units to improve consumption measurement. It is expected that these meter replacements will lead to an increase in overall company revenue and thus a reduction in NRW. When using these meters it is important that these meters are checked regularly for the battery replacement and all the electronic communication. Recommended Customer Meter Testing Provisions Review consumption history (look for over or under sizing) Potential sizing issue conduct a building inspection or detailed profile in the existing meter. If sized incorrectly change the meter to proper size If sizing is not an issue: Test meter using a portable ultrasonic clampon meter unit (at various flow rates). Compute a weighted accuracy based on the average recorded volume. If test results determine the meter is outside acceptable accuracy limits, replace or refurbish the meters. If the meter is refurbished, complete another accuracy test to ensure the service work has corrected the meter error within acceptable accuracy limits Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 9

13 Ensure all test results and servicing are properly logged and recorded for future purposes. The activities mentioned above can be completed in-house by PDAM Surabaya or outsourced to another Contractor with suitable experience in conducting the said works. Meters should be recalibrated on a regular basis to ensure accurate water accounting and billing. Calibration will provide PDAM Surabaya with valuable information on the accuracy of the quantity of water being supplied, leading to appropriate decisions on maintenance or replacement frequency. Meters with results beyond accuracy limits with reference to the table above should not remain in service unless repaired. 1.4 Reservoir Overflow Control Overflows from reservoirs are one of the major contributors of NRW however they can be easily quantified and reduced. Water utility companies can observe overflows then estimate the average duration and flow rate of the events. It is essential to continually monitor reservoir levels and to effectively eliminate reservoir overflows. It is understood that PDAM Surabaya has only few reservoirs in their water supply system which are being supplied by pumping stations. Installing continuous reservoir level monitoring (Remote Monitoring System using SMS technology) at all of these reservoirs will be worthwhile as not only can PDAM monitor reservoir overflows, this data can also be integrated to an alarm/warning system (Hi-Level or Low Level Sensors) to automate the controls of the pumping stations to ensure the optimum operation of the pumps in service. This system will enable PDAM Surabaya to continually monitor its reservoir levels, effectively operate the pumping stations and effectively eliminate reservoir overflows. As with all electronic systems it is important to verify their functionality on a regular basis to ensure that they are working correctly. RWS recommends PDAM Surabaya to setup a dedicated reservoir monitoring team equipped with necessary tools, to undertake periodic maintenance at least twice a year of the reservoir level monitoring equipment, to ensure its functionality. It is also recommended that the reservoirs in Surabaya city will have control valves installed at their inlet pipes to control the level of the reservoir, thus totally ensuring no overflows. The reservoir monitoring team will undertake regular visits to each reservoir to undertake maintenance of the control valves and to check the status of the reservoir level sensors. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 10

14 1.5 Inter-Zone Metering According to the Task 2 report, PDAM Surabaya has already divided their billing areas into 5 major zones which are named as zone 1 to zone 5. However, according to the latest operational data from PDAM Surabaya, there are 6 zones and the additional zone is labelled as zone 0. These zones were purposely created to manage the monthly meter reading and which later could be compared with the total inflow into the zones. These large zones have been divided into smaller subzones to facilitate the creation of DMA set up. To determine the NRW levels of high level water supply system of the Surabaya city, it is recommended to install permanent meters at the inflow and outflow of every zone. By doing so, the over-all water balance of the water supply system can be calculated; zones with high losses can be identified and/or prioritized for NRW reduction activities. Below is the tabulated summary of Surabaya Zone Information: Zone Zone Connection Supply Hours Propose Number of DMAs Number of Inlet Number of Outlet Inlet & Outlet Total The proposed permanent meters will be of full-bore fix-flanged electromagnetic type fitted with SMS data loggers that will transmit data to PDAM Surabaya operations office for continuous data monitoring. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 11

15 1.6 DMA Establishment In Task 3 (DMA Pilot Study), DMA establishment procedures, NRW data analysis and leak detection techniques were demonstrated and two pilot DMAs were successfully established. It was also identified within the Task 3 report that the volume of water lost and baseline NRW levels of the 2 pilot DMAs are: For DMA 202A is 1,652 cubic meter per day (19.12 liters per second) or 46.4 % For DMA 109A is 1, cubic meter per day (11.70 liters per second) or % Given the successful establishment of the 2 pilot DMAs, it is recommended that the procedures formulated in Task 3 DMA Pilot Study under section 1. DMA Establishment to be replicated in the 326 proposed new DMAs within Zones of PDAM Surabaya and follow the procedures outlined in the attached OPERATIONAL MANUAL FOR DMA ESTABLISHMENT. 1.7 Leakage Reduction Activities NRW reduction activities proceeded after successfully establishing and analyzing DMA 202A and 109A. Leak localization was undertaken using Step-Testing and leaks were found using Visual and Sounding methods with the aide of Ground Microphones. It is recommended that the activities undertaken in the task 3 report 1.8 NRW Reduction Activities to be done on the 326 DMAs that will be established. 1.8 Pressure Management The results of Task 3 (DMA Pilot Study) showed that Pressure management is not feasible to be implemented as the pressures within DMAs 202A and 109A are at a low range. However, for the zones which are having excessive pressure, there is still potential to reduce the leakage by managing the system pressures. Below is the tabulation Average Pressures reported within the 6 zones of Surabaya city and the pressure distribution map of Surabaya city water supply system: Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 12

16 Zone Zone Connection Supply Hours Average Pressure Propose Number of DMA Number of Inlet Number of Outlet Inlet & Outlet , , , , , Total 390, Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 13

17 Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 14 Ranhill Water Services Sdn. Bhd.

18 Pressure management has increasingly become popular and cost effective method to conserve network assets and water. It is recommended to PDAM Surabaya to use hydraulic models in designing Pressure Management Areas. However, if funding is insufficient for a complete hydraulic modelling and NRW is still high, then building models of Pressure Management Areas will allow hydraulic models to be built in stages, at a lower annual cost. This can be done by conducting pressure surveys for the whole water supply network of Surabaya city specifically targeting feeder primary mains and large secondary mains. Upon determination of areas in the water supply network with excessive pressure compared to average network pressure, pressure regulating valves (PRVs) and system monitoring points will be recommended to be installed to achieve more consistent and lower water pressure levels across the water supply network. In some areas where one-time pressure reduction will not be applicable due to very low pressures during peak hours of the day or times where usage of water is at the highest, PRVs with a timed controller is recommended to optimize pressures within the network. The establishment and progressive introduction of Pressure Management Areas in the water supply system of Surabaya will have immediate and long lasting benefits as follows: Extend pipe life reduce leakage reduce pipe burst frequency 1.9 Establishment of Control Room The monitoring of the individual DMAs, through SMS data loggers is important in the sense that it will alert PDAM Surabaya immediately if a problem occur and will potentially reduce the subsequent time to locate and repair. This continuous monitoring and alert system will ultimately reduce the volume of water lost in the water supply system. The control room is an integral component of the NRW reduction strategy implementation as it will act as the nerve command center where all field Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 15

19 information will be collected, analyzed and responded. It will perform, among others, the following functions: Data logger setting up Data gathering from all SMS loggers Data logger monitoring Analysis of Data logger results Monthly reporting of NRW data It is proposed that under in this strategy a central control room be established within PDAM Surabaya s operational office. This control room would be equipped with the following equipment: 2 Nos. - Server 2 Nos. - PC 4 No. - Digital Modems 2 No. - Data Logger Software 1 No. - A3 Color Printer Shown below is at the schematic presentation of data gathering and transmitting process through SMS loggers: GSM Network Mobile phones Alarm MultiLog SMS GSM Modem PC Server Data storage Graph Data Analysis Pressure & Flow meter Field display, read using PDA/Notebook PC In addition to the above technical equipments, all necessary furniture, soft boards and white boards must be provided to ensure smooth operation of the proposed control room. Office space for the above must be allocated by PDAM Surabaya and installation, renovation and electrical works shall be provided as well. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 16

20 This control room can also be used as the maintenance and updating station for any GIS and network modeling systems within PDAM Surabaya Call Centre Improvement PDAM Surabaya has an existing Call and SMS centre to receive the feedback and complaints from consumers. Below is the existing contact information for Call and SMS Centres: The complaints received are compiled and then forwarded therewith to the respective departments recipient of the complaint. The brief description of PDAM Surabaya s existing Call Centre facilities is described below: Computers: 9 nine units Mode of Communication: Phone and SMS Manpower: 32 personnel (included outsourced staff) The following items are recommended to be included into PDAM Surabaya s existing call centre facilities to enhance the flow of information and data management: Server/back up server : 1 number server / backup server for the purpose of data storage and integration to other Business/Company Information Systems Multimedia : Projector for Bulletin Information/Urgent Matters (1 unit) Wide Screen Monitors : LCD 42" (at least 3 numbers) Printer : A3/A4 laser jet printer for output printing and filing (1 number) With the proposed improvements in the existing call centre, advancements to the the current system can be completed to expedite addressing customer complaints, especially those cases related to water theft and Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 17

21 leakages. One initiative proposed for this strategy is integrating the existing Call and SMS centre with a Job Management System (JMS) and establishment of a Panel of Accredited Contractors or In-House Maintenance/Leak Repair Crews. Below is the conceptual diagram of the proposed improvements for the existing Call and SMS centre: CUSTOMER COMPLAINT Customer call the Call Center to lodge complaint. With every complaint customer will receive a report number for future reference. Leak Repair Crew/Panel Contractors At Work On-Line Thru JMS CALL CENTRE Log-in calls and assess situation for further action Instruct Maintenance Units Maintenance Units instruct Leak Repair Crew/Panel Contractors to do Work Inform Maintenance Units once problem resolved (closed case) Inform Call Center if the job is completed Maintenance Units Job Management System Job Management System (JMS) is an IT system that provides a database to record and manage information, feedback and complaints from customers. JMS also creates work orders and job status. The Jobs are re-routed to the various Maintenance Units located at all areas for actions to be taken. Information from JMS can be used for evaluation, planning and decision making Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 18

22 Below shows sample photographs of Call Center and JMS Activities: Panel of Accredited Contractors or In-House Maintenance/Leak Repair Crew Maintenance and leak repairs can be either outsourced to qualified contractors or can be done in-house by PDAM Surabaya. To ensure quality and speedily completion of works all contractors undertaking works will be approved in prior by PDAM Surabaya. All leak repair and construction works will be undertaken using methods & materials to PDAM standard specification. PDAM construction and installation supervisors will ensure that all works and leak repairs are undertaken, and materials supplied meet these standard specification. The performance of each contractor is also recommended be monitored and periodically assessed to ensure that they have valid contractor licenses or accreditation and they are suitable to undertake further works. Another option is the establishment of In-House Maintenance/Leak Repair Crew within PDAM Surabaya. Though less advantageous in terms of speed of completion and overheads compared to outsourcing; establishment of an in-house maintenance/leak repair crew will have its own advantage in terms of quality control and quality assurance Asset Maintenance Strategic Plan Having determined that part of the asset base which continues to support service delivery and the risks that these assets pose to the ongoing service delivery, the department is equipped to develop the Asset Maintenance Strategic Plan. The Plan will determine the work required to efficiently and effectively address the risks of asset ownership and their impact on service. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 19

23 Some part or components of the asset will fail before others. Timely attention to these repairs can allow the remainder of the system to continue in service. Maintenance slows the overall deterioration of the asset by restoring the condition of its short life components and allows its overall full service life to be achieved. Asset maintenance levels should ensure the asset continues to support delivery of existing service levels. Benefits of Asset Maintenance Planning Asset Maintenance planning is a detailed assessment of those assets or asset segments, which require only strategic maintenance in order to satisfy the delivery of service. It is also a detailed functional analysis of maintenance needs aimed at ensuring assets remain productive at the lowest possible long-term cost. The benefits to company as a whole are: Assets perform at optimum levels, reducing service disruptions and losses due to asset failure Asset repair or replacement can be compared to best suit service delivery needs The lifespan of assets can be prolonged System Maintenance Many of the NRW losses that arise can be prevented through preventative system maintenance. The following preventative system maintenance activities should be undertaken by the relevant operational departments within PDAM Surabaya as detailed below: All Production meters to undergo electrical functionality and volumetric accuracy tests once a year Each production meter is recommended to be tested for both electrical functionality, where necessary, and volumetric accuracy, at least once a year. These tests can be carried out by either externally approved contractors or internally by PDAM staff using valid testing equipment. All air valves to be serviced at least once per year The good operation of air valves is an essential part in reducing pipe bursts. To ensure that PDAM Surabaya s air valves are operating efficiently, they should be serviced at least once per year. This servicing will involve dismantling the air valve, cleaning all of the parts and replacing those that are deemed too worn or are broken. All valves to be operated every six months Most isolation valves operate at the fully open position and are only used during emergency or repair works. To ensure that these valves Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 20

24 remain operationally sound they should be operated once every six months. Due to the large size of some of these valves, it is recommended that PDAM use automatic hydraulic valve operators. These will reduce the time taken and necessary manpower to operate each valve. During this operation any faults to valve, broken spindle, leakage, nonclosure, etc, should be reported immediately or if possible rectified on site. Those valves reported as faulty should be repaired or replaced immediately. All control valves to be serviced every six months To ensure correct operation of PDAM s control valves (PRV or Altitude Valves) it is important that they are serviced every six months. This servicing will involve dismantling and cleaning of the main valve body, any pilot valves and the strainer. During this operation any faults to the control valve, broken diaphragm, damaged pilot, etc, should be reported immediately or if possible rectified on site. Those control valves reported as faulty should be repaired or replaced immediately. To ensure speedy rectification of any reported faults, it is recommended that a stock of essential spare parts be maintained at each of the district stores. All reservoirs to be tested for leakage once every 3 years Reservoir leakage can become a significant component of NRW if not detected quickly and remedial works undertaken. Some reservoir leakage can be easy to locate with visible water leaks from the walls or base, if an elevated tank. However many reservoirs are located at ground level, where leakage from the base cannot be easily seen. To check for leakage in these cases a reservoir leakage drop test can be undertaken. It is recommended that a reservoir leakage drop test be undertaken for each reservoir at least once every 3 years. All reservoirs to be cleaned at least once every five years As well as being a common source of customer complaints, dirty water can have a serious effect on the accuracy of PDAM Surabaya customer meters. Sediment particles in the water can build up within the meter s mechanical parts and significantly reduce their accuracy. The sediment particles, which enter the system through leaks, bursts, poor treatment processes and open reservoirs, need to be removed in all areas of the system. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 21

25 Reservoirs are an area where the water velocity reduces suddenly, causing any particles to sink to the bottom and build up. This build up of sediment needs to be removed, by cleaning the reservoir at least once every five years. All consumer meters of size of 38mm (1.5 ) or greater in size to be physically serviced at least once per year Each meter will be dismantled and the parts thoroughly cleaned. Upon being dismantled, if the meter appears to be broken, then it will be replaced immediately. All customer meter isolation valves operate in the fully open position and are only used in emergency or repair works. To ensure that these valves remain operationally sound they should be operated once every six months. During this operation any faults to valve, broken spindle, leakage, nonclosure, etc, should be reported immediately or if possible rectified on site. Those valves reported as faulty should be repaired or replaced immediately. In addition the strainer will be dismantled and thoroughly cleaned. If the strainer cannot be dismantled due to severe encrustation of deposits, the strainer should be replaced immediately. All consumer meters of below size of 38mm (1.5 ) to be physically tested, based on receipt of a customer complaint or based on results of customer meter accuracy tests. Each meter will be disconnected and taken back to the meter testing lab for testing of accuracy. Upon being disconnected, if the meter appears to be broken, then it will be replaced immediately. Periodic mains flushing, at least once a year, to reduce scaling inside the pipes and improve distribution water quality system As with reservoirs, sediment particles can enter the distribution system through leaks, bursts, poor treatment processes and open reservoirs. These sediments can cause scaling inside the pipe walls and therefore need to be removed in all areas of the distribution system. Periodic mains flushing has been proven as an effective method in improving distribution water quality and is therefore recommended to be included in the routine asset maintenance programs of PDAM Surabaya. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 22

26 Capital Project Planning PDAM to develop a ten year capital planning program All of PDAM Surabaya s assets were designed with a specific design life. These design lives will differ depending on type of asset, material, quality of installation and extent of any maintenance programs. The capital expenditure required to replace assets, once they are no longer operationally sound, can be quite large. To ensure that assets do not become a financial or technical burden to PDAM Surabaya, it is proposed that a ten year asset replacement program be developed. The proposed ten year capital planning program will be the master plan which shall be reviewed and revised every 3 years. The 3 years will be the medium-term planning which will schedule impending major tasks and asset downtime (new and refurbished) programs, resources and will be the basis for Company budgeting and business plan. This program will also enable the analysis of all PDAM Surabaya assets and determine expected operating life and thus expected time of replacement. From this analysis, a year by year program can be made of what will be required to be replaced. The asset replacement program can then be used to plan budget and human resource needs over a ten year period, providing invaluable data during tariff negotiations. GIS Updating and Network Modelling On top of developing Asset Maintenance Strategic Plan the following initiatives will also help maximize the useful life of PDAM Surabaya water supply system assets and improve operational efficiency: GIS Updating Network Modelling An accurate GIS map to be made readily available, for all appropriate PDAM staff Most of PDAM Surabaya pipes are below ground and as such can be difficult to locate exactly. The use of accurate maps is essential in reducing the time to locate mains and reduce the amount of water lost. GIS mapping is an ideal method of managing up to date and accurate maps of the pipe network. These GIS maps have a background map, showing roads, properties, etc, making locating of pipes, in relation to roads and properties, very easy. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 23

27 It is recommended for PDAM to ensure that their GIS data is up-todate to reflect the true representation of their assets and water supply system. Calibrated Network Models to be built for all areas of water supply system Understanding how the supply system operates is essential when analysing any flow or pressure data. A calibrated network model will assist greatly in this analysis and help to pinpoint the location of any system anomaly. It is recommended for PDAM to construct, calibrate and maintain a series of Network Models encompassing all mains of their water supply system. A calibrated network model will also give the following benefits to PDAM Surabaya: Identification of network issues, particularly in terms of NRW, supply and pressure anomalies Improved understanding of Network Operation / System Optimization Useful tool to manage / improve operation of the network (DMA and PMA Design) Useful tool for NRW reduction and Operations (leak localization) Useful tool for water infrastructure/asset planning and future demand impact analysis Useful tool to simulate different scenarios on the water supply system to determine the impact that these changes may have in terms of flows, pressures, water quality, proposed area developments etc Recording of Operational Usage It is essential for PDAM Surabaya to maintain proper records or water consumption that is intended for operational purposes. It is also important to determine the users and different types of usage to enable operational usage to be segregated from the total NRW of the system and not considered as unaccounted losses. It is recommended that daily records of consumption for operational usage is recorded by the relevant parties and have the consumption summarized on a monthly basis. The monthly records shall be kept and organized in the proposed PDAM Surabaya Control room. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 24

28 Below is a sample of tabulation to account for billed/unbilled, metered/unmetered operational usage. No. 1 Type of Usage Maintenance of Pipe Distribution System or Mains Flushing 2 Reservoir Cleaning 3 Fire Fighting and Fire Hydrant 4 After Leak Repairs 5 6 Public Sanitation and Sweeping Activities Water Used In PDAM Surabaya District Offices and other Government Facilities Estimated Volume of Usage (m3) Duration of Usage (days) Total Volume of Water Consumed (m 3 per month) Volume of Usage (m3 per month) 1.13 Pipe Replacement Programme Pipe replacement is a continuous process as every year pipes get older and deteriorating. Pipe replacement program is a necessity and it is advisable that PDAM Surabaya needs to allocate certain amount of budget for each year for the purpose of pipe replacement. Sections of pipe network to be replaced can be determined every year based on records, information and conditions set. To conduct a pipe replacement programme, it is important to initially determine the state of all assets in the system, initially through a network condition assessment. Condition assessment methods can be classified into direct or indirect methods: Direct methods include visual inspection, for example using CCTV cameras. Typically a 1 meter long pipe sample is exhumed every 1 km. The sample is cut in half; sand blasted to measure wall thickness and performs a variety of material tests and analyses. Direct methods also include non-destructive testing techniques such as acoustic emission, acoustic leak detection, remote field eddy current (used for cast and ductile pipes), remote field eddy current-transformer coupling (used for concrete pipes), magnetic flux leakage, ultrasonic pulse echo and guided Lambda waves, as well as seismic methods such as impact echo and spectral analysis of surface waves. Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 25

29 Indirect methods include analysis of failure history (i.e., breaks frequency or bursting rates), water audits to determine leakage levels, and flow testing to determine capacity. The results of these assessments can then be used, along with available up-to-date GIS Data, calibrated network models and future demand requirements, to develop a comprehensive plan which can help to reduce the level of losses within the system, whilst ensuring there is the capacity to meet all demands now and into the foreseeable future. Through the replacement or rehabilitation of pipes in the system, not only will the total volume of water lost be significantly reduced, but also costs associated with future inspections and active leakage control will be lower. It is commonly recognized that there is a standard distribution of the frequency at which pipes burst on the network, with a small proportion of pipes bursting at a high frequency, while other areas of the network burst at a much lower frequency. To give the greatest impact on reducing leakage, it is important to identify those pipes which have a high frequency of failure and target to replace these first. The benefit of replacing other pipes within the system will be lesser, leading to a reduced level of leakage reduction, and based on the law of diminishing returns, this will eventually lead to point where it is no longer economical to replace pipes. It is recommended for PDAM Surabaya to therefore, undertake a programme to first identify the areas of high frequency, and thus ensure that the maximum benefits, both in terms of reduced losses and economical efficiency will be obtained. There are number of reasons that a pipe needs to be replaced or rehabilitated and these include: High break or leakage rate High occurrence of leaks on joints Encrustation or corrosion, leading to high head losses Inability to meet demands Structural reinforcement Threat to life or property due to failure The first stage when undertaking pipe replacement is to identify a list of pipelines / areas to be replaced. PDAM Surabaya shall then prioritize this list for pipeline replacement based on a number of criteria. In addition, pipelines within established Zones or DMAs may be identified for replacement where the frequency of failure is high. In such cases, pipe replacement will be carried out. Volume saved after pipe replacement programme will be measured and accounted for as savings in physical loss. The selection criteria pipe replacement shall be as follows: The frequency of leaks and burst along a pipeline Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 26

30 Cost of replacement Failure profile General pipe condition Existing pipe location Age of assets Pipe replacement and rehabilitation methods There are a number of methods that can be used to replace or repair the pipe work in the system, and determining which method will be proposed for a particular location will be influenced by a number of factors including the original pipe material, asset condition and geographical location. The methods that can be considered for repairing/replacing the pipes are listed below: Open Cut Pipe replacement Sliplining Pipe Bursting Open Cut Pipe Replacement Open trenching or mains replacement is the traditional method used to replace existing assets in the system. This technique simply involves excavating to uncover the existing old pipe, removing the pipe from the ground, and replacing it with a new pipe and service connections. This method is however a very costly technique in many urban areas and is also impracticable as it often requires the closure of busy and sensitive roads to the public. This technique does often solve large losses to the system, and in some cases is the only technique available, however if other methods to repair or rehabilitate the network are applicable, these will often take precedence due to the costs and impact issues mentioned. Sliplining Slip lining is a form of trenchless technology, which is one of the simplest no dig techniques available. Using this methodology, the inside of the old pipe is cleaned out, and a new pipe is drawn or pushed through the old one. This new pipe is of a smaller diameter than the existing pipe. Once this new pipe has been laid, small excavations will be required at the service connections so that they can be reconnected. With this technique, the diameter of the pipe will be reduced, and therefore it is vital that the hydraulic carrying capacity must be Non Revenue Water (NRW) Management Strategy for Surabaya Water Company 27