A Methodology for the Breakdown of NRW into Real and Administrative Losses

The estimation of Non Revenue Water (NRW) is simple and easy for water suppliers who keep records of the system input volume and the billed authorized consumption. However, the breakdown of NRW into its two main components real and administrative which refers to the unbilled authorized consumption plus apparent losses is not an easy or straight forward task. Methods reported in the literature for the breakdown of NRW into its components are top down approach and bottom up approach. Both approaches suffer from certain limitations and shortcomings that limits their use and reduce our confidence in the results obtained by them. This paper presents a methodology that can be used to draw a line between the real and the administrative losses with an acceptable level of accuracy. This methodology is based on the fact that the administrative losses are delivered to the demand site and consequently reach the wastewater collection system whereas the real losses are lost from the system and consequently do not reach the wastewater collection system. The methodology applies water balance from the water treatment plant outlet till the inlet of the wastewater treatment plant (WWTP). The mass balance approach of the Water Evaluation And Planning (WEAP) system was implemented for this purpose. In this methodology, the breakdown of NRW into its two main components is adjusted iteratively so that the difference between WEAP calculated and measured inflow to the WWTP is minimal. The presented methodology was applied to Amman and Zarqa cities in Jordan which return their wastewater to As Samra WWTP. The results showed that this methodology is capable of dividing NRW water into its two main components with an acceptable level of accuracy.

[1]  M. Chaudhry,et al.  Leak detection in pipes by frequency response method using a step excitation , 2001 .

[2]  Steven G. Buchberger,et al.  Leak estimation in water distribution systems by statistical analysis of flow readings , 2004 .

[3]  George Tchobanoglous,et al.  Wastewater Engineering Treatment Disposal Reuse , 1972 .

[4]  Witness Mpesha,et al.  Leak detection in pipes by frequency response method using a step excitation , 2001 .

[5]  Bruno Brunone,et al.  Pressure waves as a tool for leak detection in closed conduits , 2004 .

[6]  Helena M. Ramos,et al.  Detection of Leakage Freshwater and Friction Factor Calibration in Drinking Networks Using Central Force Optimization , 2012, Water Resources Management.

[7]  Angus R. Simpson,et al.  Leak location using the pattern of the frequency response diagram in pipelines: a numerical study , 2005 .

[8]  Bryan W. Karney,et al.  Energy and Costs of Leaky Pipes: Toward Comprehensive Picture , 2002 .

[9]  Sanghyun Kim.  Extensive Development of Leak Detection Algorithm by Impulse Response Method , 2005 .

[10]  Orazio Giustolisi,et al.  Pressure-Driven Demand and Leakage Simulation for Water Distribution Networks , 2008 .

[11]  K. Vairavamoorthy,et al.  Multi-criteria Decision Analysis: A Strategic Planning Tool for Water Loss Management , 2011 .

[12]  M. Ferrante,et al.  Detecting leaks in pressurised pipes by means of transients , 2001 .

[13]  Michael J. Brennan,et al.  A comparison of time delay estimators for the detection of leak noise signals in plastic water distribution pipes , 2006 .

[14]  Saroj K. Sharma,et al.  Assessment of apparent losses in urban water systems , 2011 .

[15]  Michael J. Brennan,et al.  Leak noise propagation and attenuation in submerged plastic water pipes , 2004 .

[16]  James A. Liggett,et al.  LEAKS IN PIPE NETWORKS , 1992 .

[17]  S. Beck,et al.  Pipeline Network Features and Leak Detection by Cross-Correlation Analysis of Reflected Waves , 2005 .

[18]  B. Kingdom,et al.  The challenge of reducing non-revenue water (NRW) in developing countries - how the private sector can help : a look at performance-based service contracting , 2006 .

[19]  Zoran Kapelan,et al.  A review of methods for leakage management in pipe networks , 2010 .

[20]  Michael J. Brennan,et al.  A model of the correlation function of leak noise in buried plastic pipes , 2004 .

[21]  Michael J. Brennan,et al.  On the selection of acoustic/vibration sensors for leak detection in plastic water pipes , 2005 .

[22]  Zoran Kapelan,et al.  Incorporation of prior information on parameters in inverse transient analysis for leak detection and roughness calibration , 2004 .

[23]  Stephen R. Mounce,et al.  Burst detection using hydraulic data from water distribution systems with artificial neural networks , 2006 .

[24]  Helena M. Ramos,et al.  Standing Wave Difference Method for Leak Detection in Pipeline Systems , 2005 .

[25]  Helena M. Ramos,et al.  Pressure Control for Leakage Minimisation in Water Distribution Systems Management , 2006 .

[26]  Riku Vahala,et al.  Leakage detection in a real distribution network using a SOM , 2009 .

[27]  Gustaf Olsson,et al.  Pipeline Break Detection Using Pressure Transient Monitoring , 2005 .

[28]  Peter H. Gleick,et al.  Waste Not, Want Not: The Potential for Urban Water Conservation in California , 2003 .

[29]  Selami Kara,et al.  Implementation of Hydraulic Modelling for Water-Loss Reduction Through Pressure Management , 2012, Water Resources Management.

[30]  Jack Sieber,et al.  WEAP Water Evaluation and Planning System , 2006 .

[31]  Zoran S. Kapelan,et al.  A hybrid inverse transient model for leakage detection and roughness calibration in pipe networks , 2003 .