APPLICATION OF WATER AUDIT IN DOMESTIC WATER SUPPLY SYSTEMS Presented at
India Water Week-2013 S12- Mandatory Water Audit for Domestic and Industrial Water Supply M.S. Agrawal, Adviser (Water Resources), Planning Commission, New Delhi Dr Dinesh Chand, Additional Advisor (PHE) and V.K. Bathla, Deputy Advisor (PHE), Ministry of Drinking Water and Sanitation, New Delhi 1
Introduction • Thousands of water schemes in the country are dedicated to sourcing, treating and delivering safe water to the public and these schemes are having the problem of water loss. • Water loss from these water supply schemes- is not only confined to simple loss of revenue but also include requirement of more water to be treated requiring additional energy, chemical usage etc., resulting in wasted resources and lost revenues. • With growing concerns about shrinking budgets,PWSs must look at how to optimize their production and augment revenue. • For these reasons PWSs across the country are implementing Water Audit and water loss control (WLC) programs aiming at to reduce revenue loss and also protect public health by eliminating the threat of sanitary defects due to entry of microbial or other contaminants into treated water. 2
Water Audit • •
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Water audit in a public water supply system is in the similar lines to energy audit. This determines the amount of water lost from source of water to a distribution system including losses at users’ taps due to leakages and other reasons such as theft, unauthorized or illegal withdrawals/ connections from the systems and thus, loss of revenue of the utility. A water Audit plan gives a detailed profile of a water supply system including its distribution system, water users thereby facilitating easier and effective management of resources with improved reliability. It helps in correct diagnosis of the problems faced and suggests optimum solutions. It is also an effective tool for realistic understanding and assessment of the system’s performance level, efficiency of the service and the adaptability of the system for future expansion & rectification of faults during modernization. Elements of water audit include a record of the amount of water produced, total water supplied, water delivered to metered/ unmetered users, water losses and suggested measures to address water loss (through pinpointing & minimising leakages and other unaccounted for water losses). 3
Steps In Water Audit Exercise • To conduct a water audit of the water transmission and distribution system and water accounting practices etc. • Preparation of worksheets and sample calculations for each step of the water audit • To identify, measure all water consumption and loss • To identify and control apparent losses in metering and billing operations, and recover missed revenues • To implement a leakage and pressure management program to control real losses, conserve water and contain costs • Develop plans to assemble the proper resources, information and equipment to launch a loss-control program • Prepare work-plan for setting short, medium and long-4 term goals and estimate return on investment.
Application of Water Audit Process • Application of water audit process in domestic/ municipal sector may consist of various steps viz. water audit exercise; undertaking interventions for water conservation through leakages/ losses control and evaluation of their effectiveness; placement of regulatory framework & community involvement. 5
Water Audit Methodology • A reliable water audit methodology was developed jointly by the American Water Works Association (AWWA) and International Water Association (IWA) in year 2000. • Water balance of this methodology is given below and shows schematically the various components in which water volumes (typically one year) are tracked.
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Component-Wise Water Balance Authorized Consumption System Input Volume (corrected for known errors)
Billed Authorized Consumption
Unbilled Authorized Consumption Apparent Losses Water Losses Real Losses
Billed Metered Consumption (including water exported) Billed Unmetered Consumption Unbilled Metered Consumption Unbilled Unmetered Consumption Unauthorized Consumption Customer Metering Inaccuracies Data Handling Errors Leakage on Transmission and Distribution Mains Leakage and Overflows at Utility’s Storage Tanks Leakage on Service Connections up to point of Customer metering
Revenue Water
Non-Revenue Water (NRW)
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Component of Losses - Two Broad Types • Apparent Losses are the “paper” losses that occur in utility operations due to customer meter inaccuracies, billing system data errors and unauthorized consumption. In other words, this is the water that is consumed but is not properly measured, accounted or paid for. These losses cost utilities revenue and distort data on customer consumption patterns. • Real Losses are the physical losses of water from the distribution system, including leakage and storage overflows. These losses inflate the water utility’s production costs and stress water resources since they represent water that is extracted and treated, yet never reaches beneficial use. 8
Steps/Interventions to Reduce Water Losses
I. Infrastructure management activities to reduce real water losses.
Operation and maintenance of transmission and distribution system to prevent breakdowns in the components and the associated leakage (valves, hydrants, etc.); Material and construction standards to assure quality of future infrastructure installation; Maintain proper inventory to repair all sizes of main breaks or leaks; Inspection of water mains; observance of pressure and leakage tests; 9
Contd…. GIS mapping of system components in order to quickly find valves to isolate main breaks; Indicating leaks, repairs, complaints, theft, vandalism, etc, by geographic location to concentrate future leakage activities; Increased surveillance in areas with aging infrastructure or reported leaks; Periodically checking proper operation and control of pumps used to fill storage tanks; Leak detection surveys/studies and leak repair; Water main rehabilitation and replacement; Pressure management. Installation of telemetry system/SCADA for real time monitoring of leakage/ bursts so as to attend to the leaks without any loss of time. 10
II. Management Activities to reduce apparent water losses Metering of all source inputs, water exports or sales and customer accounts (includes both billed, authorized use and non-billed authorized); If not going to meter hydrant usage, accurately estimate and record the water used for fire fighting or flushing; Billing practices designed to detect potential problems or inconsistencies: Obtain consistent customer readings near the same day each month Eliminate or reduce human error by installing automated meter readers Account for non-billed authorized usage (such as hydrants)
Deterrence of theft or illegal usage by maintaining a visible presence, aggressively prosecuting those caught, and soliciting public involvement in reporting such crimes; Accounting and record keeping practices to improve reliability and accuracy of the water balance; more easily pinpoint water loss areas. Adopting above management activities, the Municipality/ Panchayat/ Water supply dept. Will not only increase revenues but also benefit through the extension of sustainable water supply, reduced operating cost, improved system hydraulics and utility effectiveness and a improved environmental management. 11
Other Interventions for Water Conservation An important component of water conservation involves minimizing water losses, prevention of water wastage and increasing efficiency in water use. Important action points in domestic and municipal sectors are as under: 1. Action towards reduction of losses in conveyance; 2. Management of supply through proper meter as per rational demand; 3. Intermittent domestic water supply may be adopted to check its Wasteful use. 4. Realization of appropriate water charges so that the system can be sustainable and wastage is reduced; 5. Creation of awareness among the water users 6. Evolving norms for water use for various activities and designing of optimum water supply system accordingly; 7. (a) Modification in design of accessories - flushing system, tap etc. to reduce water requirement to optimal level; (b) BIS code may be revised, if required; • (a) Possibility for recycling and reuse of water for gardening, flushing to toilets, etc. may be explored; (b) Wastewater of certain categories can be reused, if feasible; 9. Optimum quantity of water required for waste disposal - to be worked out; 10. In public buildings the taps etc. can be fitted with sensors. 12
Regulatory Mechanism for Water Conservation
Action plan
• Policy for Rationalized water pricing in urban and rural areas; Industries should be discouraged to exploit ground water by high price slabs; • Restriction on construction of new ground water structures in over -exploited and dark blocks of the country; • Metering of all ground water abstraction structures; • Controlled supply of electricity and downsizing of pump capacity in rural areas; • Regulating the water usage, trading or selling; • Provide incentives for adoption of rainwater harvesting and recharge; • Modification in building bye-laws in urban areas to make it mandatory to adopt rainwater harvesting. Action already initiated by Delhi, Andhra Pradesh, Gujarat, Haryana, Karnataka, Kerala, Maharashtra, Rajasthan, Tamil Nadu and Uttar Pradesh. Other States are required to take similar initiatives. 13
Water Users’ Association and Legal Empowerment • When water supply to domestic sector is not adequately met, some of residents use water pumps to draw water from water distribution mains to their dwellings and thereby causing hardship to other fellow residents. • Illegal tapping of water from supply lines or lifting water from canals are also prevalent at places. Moreover, the water users, in general, are less sensitive to leakage or water loss from the system. • Similarly, in case of municipal/ industrial sector, it is not very uncommon to discharge untreated or partially treated effluents into water bodies like rivers, lakes, ponds, canals etc. including ground water aquifers.
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Contd....... • In irrigation sector, Water Users’ Association (WUA), aims at involvement of farmers in water management to facilitate equitable and judicious allocation of irrigation waters among farmers of head, middle and tail reaches. • This improved collection of water user charges and which in turn provided better maintenance of the irrigation projects due to availability of more funds and enhance overall efficiency of irrigation systems. • Similar concept i.e. involvement of Panchayati Raj Institutions (PRIs)/ users in the distribution and management process in domestic and municipal sectors of water is felt essential. Users’ Associations in domestic/municipal and industrial sectors for water use may address these issues and may help in conservation of water and control pollution of water bodies from domestic and industrial pollutants. WUAs / Village Water and Sanitation Committees (VWSC) may be duly empowered through legislation or promulgation of ordinance to punish errant water users. 15
Conclusion • ‘Water audit’ is a tool which improves the knowledge and documentation of the water supply and its distribution system, problems and health risk areas and a better understanding of hot-spots in a particular water supply system for undertaking appropriate interventions and management strategies. • Further, promotion of mass awareness, active participation of water users and appropriate & effective regulatory frame for water conservation are essential elements for successful better water utilisation and better control of water losses. 16
THANKS
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