A filtering algorithm for high-resolution flow traces to improve water end-use analysis

[EN] One of the main difficulties encountered when designing automatic tools for water end use identification is the inherent noise present in recorded flow traces. Noise is mainly caused by the inability of the monitoring equipment to accurately register water consumption and data-loggers to register, without distortion, the signal received from the water meter. A universal filtering algorithm has been developed to remove noise and simplify water consumption flow traces with the aim of improving future automatic end use identification algorithms. The performance of the proposed filtering methodology is assessed through the analysis of 21,647 events. Water consumption data were sourced from two different water end use studies, having consumers and monitoring equipment with dissimilar characteristics. The results obtained show that the algorithm is capable of removing an average of 70% of the data points that constitute the flow traces of the complex events examined. The simplified flow traces allow for faster and more accurate disaggregation and classification algorithms, without losing significant information or distorting the original signal. The ability of the proposed filtering algorithm to fit the original flow traces was benchmarked using the Kling-Gupta efficiency coefficient, obtaining an average value above 0.79.This study has received funding by the IMPADAPT project/CGL2013-48424-C2-1-R from the Spanish ministry MINECO with European FEDER funds and from the European Union's Seventh Framework Programme (FP7/2007e2013) under grant agreement no. 619172 (SmartH2O: an ICT Platform to Leverage on Social Computing for the Efficient Management of Water Consumption).Pastor-Jabaloyes, L.; Arregui De La Cruz, F.; Cobacho Jordán, R. (2018). A filtering algorithm for high-resolution flow traces to improve water end-use analysis. Water Science & Technology: Water Supply. 19(2):451-462. https://doi.org/10.2166/ws.2018.090S45146219

Influence of Butterfly and Gate Valves Upstream Large Water Meters

[EN] The research presented was conducted to quantify the effects of butterfly and gate valves located upstream water meters with diameters larger than 50 mm. Errors caused by these valves can have an enormous financial impact taking into consideration that a small percentage of variation in the error of a large meter is typically related to a significant volume of water. The uncertainty on the economic impact that a valve installed upstream of a medium size water meter leads to many water utilities to oversize the meter chambers in order to mitigate the potential negative errors. Most manufacturers approve their meters for a specific flow disturbance sensitivity class according to the standard ISO 4064-1:2018. Under this classification, a correct operation of the meters requires a certain length of straight section of pipe upstream the meter. However, this classification of the meters cannot consider all types of flow perturbances. For this study, two types of valves, butterfly and gate, were tested upstream ten brand-new water meters from six different manufacturers constructed in four different metering technologies: single-jet, Woltmann, electromagnetic and ultrasonic. In each meter unit was tested at five flow rates, from minimum to the overload flow rates. The tests were conducted with valves set in different orientations, closing degrees, and upstream distances from the water meters under study. The research shows that the valves used can produce significant deviations in the measuring errors with respect the errors found for undistorted working conditions.A. would like to thank Fernando Legarda for the original idea and support to install the test bench. Also, would like to thank Cesar Samperio and Iker Bidaurratzaga from Amvisa, Koldo Urkullu and Juan Luis Mozo from Udal Sareak, Unai Lerma and Joaquin Soler from CABB and Francesc Gavara from FACSA for providing the water meters required to carry out this research and their support during the whole process. I.A. and I.B. would like to thank also to the Basque Government research group IT1314-19.Albaina, I.; Arregui De La Cruz, F.; Bidaguren-Alday, C.; Bidaguren, I. (2020). Influence of Butterfly and Gate Valves Upstream Large Water Meters. Water. 12(9):1-24. https://doi.org/10.3390/w12092563S12412

Metrological analysis of water meters in water supply utilities

[EN] One of the major issues affecting water utilities is the high level of water losses. Nonrevenue water (NRW) is the difference between the amount of water put into the distribution system and the amount of water billed to consumers. Traditionally most of the efforts focused mainly on the real losses reduction. Commercial losses are the nonphysical losses in that no water is phycically lost from the distribution system and its principal component is the customer meter inaccuracy. As any other measuring device, a water meter is not a perfect instrument and when installed it is not capable of registering the exact amount of water consumed by a user. This means that a portion of the water consumed may not be registered and therefore not billed to the customer. As meter inaccuracies are recognised to be a critical component of apparent losses, it is important to quantify the magnitude of these measuring errors. For this reason, an ambitious research project has been developed in FACSA, with ITA-Univerisitat Politècnica de València, to analyze the metrological behavior of the meters and thus obtain the measurement error of water utilities.[ES] Uno de los desafíos más importantes que debe afrontar cualquier empresa gestora del ciclo integral del agua, es la reducción de los elevados niveles de pérdidas. Tradicionalmente todos los esfuerzos se han centrado en minimizar las pérdidas reales, pero en lo que a las pérdidas comerciales se refiere, aquellas que representan el volumen de agua realmente suministrado a los usuarios pero que por diferentes causas no es registrado, mucho es el camino aún por recorrer. El principal componente de las pérdidas comerciales son los errores de medición de los contadores. Como cualquier otro dispositivo de medición, los contadores de agua no son instrumentos perfectos y una vez instalados no son capaces de registrar la cantidad exacta de agua consumida por un usuario, por lo que una parte del agua consumida no puede ser ni registrada ni facturada al cliente. Es por ello que se ha desarrollado en FACSA, junto al ITA de la Universitat Politècnica de València (UPV), un ambicioso proyecto de investigación con el objetivo de estudiar el comportamiento metrológico de los contadores y así obtener el error de medición del parque de contadores.Gavara-Tortes, FJ.; Arregui De La Cruz, F. (2018). Análisis metrológico de contadores de agua en abastecimientos. Tecnoaqua. (30):72-80. http://hdl.handle.net/10251/120333S72803

Metrological analysis of water meters in water supply utilities

[EN] One of the major issues affecting water utilities is the high level of water losses. Nonrevenue water (NRW) is the difference between the amount of water put into the distribution system and the amount of water billed to consumers. Traditionally most of the efforts focused mainly on the real losses reduction. Commercial losses are the nonphysical losses in that no water is phycically lost from the distribution system and its principal component is the customer meter inaccuracy. As any other measuring device, a water meter is not a perfect instrument and when installed it is not capable of registering the exact amount of water consumed by a user. This means that a portion of the water consumed may not be registered and therefore not billed to the customer. As meter inaccuracies are recognised to be a critical component of apparent losses, it is important to quantify the magnitude of these measuring errors. For this reason, an ambitious research project has been developed in FACSA, with ITA-Univerisitat Politècnica de València, to analyze the metrological behavior of the meters and thus obtain the measurement error of water utilities.[ES] Uno de los desafíos más importantes que debe afrontar cualquier empresa gestora del ciclo integral del agua, es la reducción de los elevados niveles de pérdidas. Tradicionalmente todos los esfuerzos se han centrado en minimizar las pérdidas reales, pero en lo que a las pérdidas comerciales se refiere, aquellas que representan el volumen de agua realmente suministrado a los usuarios pero que por diferentes causas no es registrado, mucho es el camino aún por recorrer. El principal componente de las pérdidas comerciales son los errores de medición de los contadores. Como cualquier otro dispositivo de medición, los contadores de agua no son instrumentos perfectos y una vez instalados no son capaces de registrar la cantidad exacta de agua consumida por un usuario, por lo que una parte del agua consumida no puede ser ni registrada ni facturada al cliente. Es por ello que se ha desarrollado en FACSA, junto al ITA de la Universitat Politècnica de València (UPV), un ambicioso proyecto de investigación con el objetivo de estudiar el comportamiento metrológico de los contadores y así obtener el error de medición del parque de contadores.Gavara-Tortes, FJ.; Arregui De La Cruz, F. (2018). Análisis metrológico de contadores de agua en abastecimientos. Tecnoaqua. (30):72-80. http://hdl.handle.net/10251/120333S72803

Discussion of Energy Metrics for Water Distribution System Assessment: Case Study of the Toronto Network by Rebecca Dziedzic and Bryan W. Karney

[EN] The paper under discussion presents a metric that allows auditing the energy performance of pressurized water networks. This same metric (except for the period used to perform the audit) was already presented by the discussers in this journal (Cabrera et al. 2010). In the discussers opinion, this poses a minor difference from a conceptual point of view. While in the discussers proposal integration was extended to longer periods (days or years) to gain a general understanding of the issue, the paper under discussion uses shorter periods of time similar to those used to analyze network behavior with extended period simulation. The increased time resolution allows delving into greater depth in the assessment as well as developing and comparing different scenarios (e.g., winter versus summer).Cabrera Marcet, E.; Gomez Selles, E.; Cabrera Rochera, E.; Arregui De La Cruz, F. (2016). Discussion of Energy Metrics for Water Distribution System Assessment: Case Study of the Toronto Network by Rebecca Dziedzic and Bryan W. Karney. Journal of Water Resources Planning and Management. 142(11):07016003-1-07016003-3. doi:10.1061/(ASCE)WR.1943-5452.0000721S07016003-107016003-31421

Private Water Storage Tanks: Evaluating Their Inefficiencies

[EN] Private water storage tanks are often considered as very inefficient devices than can only be justified in systems that suffer frequent water service interruptions. This paper presents the results obtained after studying four different aspects of this question: the effect of this kind of tanks on water losses, unaccounted for water, time modulation curve and energy losses (other implications, such as those related to water quality deterioration, remain out of the scope of the study). Conclusions for each particular point will turn uneven, specially highlighting the effect on the meter global error and unregistered water. In any case, all four points, as well as several additional issues to be considered, are described and evaluated.Authors would like to thank the essential support of SPANISH MINISTRY OF EDUCATION, through the research project “Ordenación y valoración de estrategias orientadas a la progresiva eliminación de los depósitos de almacenamiento de los usuarios en los abastecimientos de agua urbanos”. CGL2005-03666/HID.Cobacho Jordán, R.; Arregui De La Cruz, F.; Cabrera Marcet, E.; Cabrera Rochera, E. (2008). Private Water Storage Tanks: Evaluating Their Inefficiencies. Water Practice & Technology. 3(1):1-8. https://doi.org/10.2166/wpt.2008.025S183

Accuracy of Solid-State Residential Water Meters under Intermittent Flow Conditions

[EN] Accurate water consumption measurement of customers is a crucial component of water utility sustainability. During the last decade, sophisticated measuring technologies without moving components, known as solid-state water meters or static meters, have emerged. Solid-state water meters promise an improved accuracy with more processing and transmission capabilities in comparison with traditional mechanical meters. A compromise needs to be reached between energy consumption and battery life as all these new features are extremely demanding on electric energy. The usual approach adopted by the manufacturer is to reduce the frequency with which static meters take measurements of the circulating flow. This reduction in signal sampling frequency can have a significant effect on the accuracy of the instruments when measuring water consumption events of 30 s or less, these events being common in residential customers. The research presented analyses of the metrological performance of 28 commercially available solid-state water meters from six different manufacturers in the presence of intermittent flows of various durations. The results show that the magnitude and dispersion of the error under intermittent flows is significantly larger in comparison to steady state flow conditions. The ultrasonic meters examined were more influenced by the intermittency than the electromagnetic meters.The work was partially funded by the Catedra UPV-FACSA-FOVASA de Agua, Residuos y Economia Circular. The authors are very grateful for the funding support. The authors would like to acknowledge the material and assistance received from FACSA during the development of the research.Arregui De La Cruz, F.; Pastor-Jabaloyes, L.; Mercedes, AV.; Gavara-Tortes, FJ. (2020). Accuracy of Solid-State Residential Water Meters under Intermittent Flow Conditions. Sensors. 20(18):1-28. https://doi.org/10.3390/s20185339S1282018Szilveszter, S., Beltran, R., & Fuentes, A. (2015). Performance analysis of the domestic water meter park in water supply network of Ibarra, Ecuador. Urban Water Journal, 14(1), 85-96. doi:10.1080/1573062x.2015.1057181Arregui, F. ., Cabrera, E., Cobacho, R., & García-Serra, J. (2006). Reducing Apparent Losses Caused By Meters Inaccuracies. Water Practice and Technology, 1(4). doi:10.2166/wpt.2006.093Richards, G. L., Johnson, M. C., & Barfuss, S. L. (2010). Apparent losses caused by water meter inaccuracies at ultralow flows. Journal - American Water Works Association, 102(5), 123-132. doi:10.1002/j.1551-8833.2010.tb10115.xMbabazi, D., Banadda, N., Kiggundu, N., Mutikanga, H., & Babu, M. (2015). Determination of domestic water meter accuracy degradation rates in Uganda. Journal of Water Supply: Research and Technology-Aqua, 64(4), 486-492. doi:10.2166/aqua.2015.083Mutikanga, H., Sharma, S., & Vairavamoorthy, K. (2011). Investigating water meter performance in developing countries: A case study of Kampala, Uganda. Water SA, 37(4). doi:10.4314/wsa.v37i4.18Stoker, D. M., Barfuss, S. L., & Johnson, M. C. (2012). Flow measurement accuracies of in-service residential water meters. Journal - American Water Works Association, 104(12), E637-E642. doi:10.5942/jawwa.2012.104.0145Arregui, F., Gavara, F., Soriano, J., & Pastor-Jabaloyes, L. (2018). Performance Analysis of Ageing Single-Jet Water Meters for Measuring Residential Water Consumption. Water, 10(5), 612. doi:10.3390/w10050612ISO - ISO 4064-1:2014 - Water Meters for Cold Potable Water and Hot Water—Part 1: Metrological and Technical Requirements https://www.iso.org/standard/55371.htmlBuck, B. S., Johnson, M. C., & Barfuss, S. L. (2012). Effects of particulates on water meter accuracy through expected life. Journal - American Water Works Association, 104(4), E231-E242. doi:10.5942/jawwa.2012.104.0054Blokker, E. J. M., Vreeburg, J. H. G., & van Dijk, J. C. (2010). Simulating Residential Water Demand with a Stochastic End-Use Model. Journal of Water Resources Planning and Management, 136(1), 19-26. doi:10.1061/(asce)wr.1943-5452.0000002ISO - ISO 4064-2:2014 - Water Meters for Cold Potable Water and Hot Water—Part 2: Test Methods https://www.iso.org/standard/55383.htmlChadwick, J. R., Barfuss, S. L., & Johnson, M. C. (2018). Accuracy of residential water meters in response to short, intermittent flows. AWWA Water Science, 1(1). doi:10.1002/aws2.1010R: A Language and Environment for Statistical Computing 2019 https://www.R-project.org/OIML—OIML R 49-1:2013—Water Meters for Cold Potable Water and Hot Water—Part 1: Metrological and Technical Requirements https://www.oiml.org/en/files/pdf_r/r049-1-e13.pdfBuchberger, S. G., & Wu, L. (1995). Model for Instantaneous Residential Water Demands. Journal of Hydraulic Engineering, 121(3), 232-246. doi:10.1061/(asce)0733-9429(1995)121:3(232)Alvisi, S. (2003). Water Resources Management, 17(3), 197-222. doi:10.1023/a:1024100518186Alcocer-Yamanaka, V. H., Tzatchkov, V. G., & Arreguin-Cortes, F. I. (2012). Modeling of Drinking Water Distribution Networks Using Stochastic Demand. Water Resources Management, 26(7), 1779-1792. doi:10.1007/s11269-012-9979-

Graphical method to calculate the optimum replacement period for water meters

Calculating the optimum replacement period of meters has always been a major concern for water utility managers. Its determination is time-consuming and requires multiple calculations. This note presents a graphical method to obtain, in a simple but accurate manner, the optimum replacement period of installed meters. For this purpose, a chart has been produced, in which the most in¿uencing variables are considered. These variables include the degradation rate of the weighted error of the meters, the selling price of water, the acquisition and installation cost of the meters, the volume consumed by the users and the discount rate. The chart also allows for a quick sensitivity analysis of different options. For example, by plotting straight lines it is possible to determine by how much the optimum replacement frequency of a meter would change if it degrades at a different rate than expected or if the selling price of water increases.Spanish Ministry of Science and Innovation, through Project No. CGL2008-01910.Arregui De La Cruz, F.; Cobacho Jordán, R.; Cabrera Rochera, E.; Espert Alemany, VB. (2011). Graphical method to calculate the optimum replacement period for water meters. Journal of Water Resources Planning and Management. 137(1):143-146. https://doi.org/10.1061/(ASCE)WR.1943-5452.0000100S143146137

Simplifying water consumption flow traces for improving end use recognition: a case study

[EN] The success of automatic water end use disaggregation and classification strategies greatly depends on the filtering and signal conditioning of the flow traces recorded. The work presented proposes a new filtering algorithm of water consumption flow traces. To improve the performance of the filter, the parameters driving the process are found per event by an automatically calibration procedure. These parameters are selected to ensure the maximum adaptability and simplification of the filtered flow traces. The methodology has been tested with 5210 consumption events obtained from a measurement campaign conducted in a Spanish city. The results obtained show that the filtering algorithm is capable of significantly simplifying the original flow traces while maintaining their main characteristics. On average, it has been found that the most complex events can be described using only 10% of the input data. This analysis can be used to make more efficient the filtering procedure proposed.[ES] El éxito de estrategias para la desagregación y clasificación automática de los consumos de agua en usos finales depende de un adecuado filtrado previo de las trazas de caudal registradas. Se propone un nuevo algoritmo de filtrado, cuyos parámetros de entrada se ajustan mediante un proceso de calibración automático por evento de consumo, asegurando la adaptabilidad y simplificación de la traza filtrada a la original. Esta herramienta se aplica a un caso de estudio mediante el análisis de 5210 eventos de consumo, procedentes de una campaña de monitorización en una ciudad española. Los resultados muestran que el filtro es capaz de simplificar sustancialmente las trazas de caudal manteniendo la información esencial. En media, las trazas de caudal de eventos más complejos pueden definirse con menos del 10% de los puntos de las trazas originales. Además, el análisis realizado permite identificar diversas estrategias para mejorar y optimizar el proceso de filtrado.El trabajo presentado en este artículo ha sido posible gracias al Proyecto IMPADAPT/CGL2013-48424-C2-1-R del Ministerio de Economía y Competitividad de España con fondos FEDER y al VII Programa Marco de la Unión Europea, bajo el acuerdo de financiación no. 619172(SmartH2O: an ICT Platform to leverage on Social Computing for the efficient management of Water Consumption).Pastor Jabaloyes, L.; Arregui De La Cruz, F.; Cobacho Jordán, R. (2018). Mejora del reconocimiento de usos finales del agua mediante la simplificación de la traza de caudal: un caso de estudio. Ingeniería del Agua. 22(4):195-208. https://doi.org/10.4995/ia.2018.9476SWORD195208224Arregui, F. (2015). New software tool for water End-Uses studies. Presentation of 8th IWA International Conference on Water Efficiency and Performance Assessment of Water Services, Cincinnati, USA.Cominola, A., Giuliani, M., Piga, D., Castelletti, A., Rizzoli, A.E. (2015). Benefits and challenges of using smart meters for advancing residential water demand modeling and management: A review. Environmental Modelling & Software, 72, 198-214, https://doi.org/10.1016/j.envsoft.2015.07.012DeOreo,W.B., Heaney, J.P., Mayer, P.W. (1996). Flow trace analysis to assess water use. American Water Works Association, 88, 79-90. https://doi.org/10.1002/j.1551-8833.1996.tb06487.xFielding, K.S., Spinks, A., Russell, S., McCrea, R., Stewart, R.A., Gardner, J. (2013). An experimental test of voluntary strategies to promote urban water demand management. Journal of Environmental Management, 114, 343-351. https://doi.org/10.1016/j.jenvman.2012.10.027Gupta, H.V., Kling, H., Yilmaz, K.K., Martinez, G.F. (2009). Decomposition of the mean squared error and NSE performance criteria: Implications for improving hydrological modelling. Journal of Hydrology, 377, 80-91,https://doi.org/10.1016/j.jhydrol.2009.08.003Kowalski, M., Marshallsay, D. (2003). A System for Improved Assessment of Domestic Water Use Components. II International Conference Efficient Use and Management of Urban Water Supply, International Water Association, Tenerife, Spain.Larson, E., Froehlich, J., Campbell, T., Haggerty, C., Atlas, L., Fogarty, J., Patel, S.N. (2012). Disaggregated water sensing from a single, pressure-based sensor: An extended analysis of HydroSense using staged experiments. Pervasive and Mobile Computing, 8, 82-102. https://doi.org/10.1016/j.pmcj.2010.08.008Nguyen, K.A., Zhang, H., Stewart, R.A. (2013a). Development of an intelligent model to categorise residential water end use events. Journal of Hydro-environment Research, 7, 182-201. https://doi.org/10.1016/j.jher.2013.02.004Nguyen, K.A., Stewart, R.A., Zhang, H. (2013b). An intelligent pattern recognition model to automate the categorisation of residential water end-use events. Environmental Modelling & Software, 47, 108-127. https://doi.org/10.1016/j.envsoft.2013.05.002Pastor-Jabaloyes, L., Arregui, F.J., Cobacho, R. (2018). Water End Use Disaggregation Based on Soft Computing Techniques. Water, 10(1), 46. https://doi.org/10.3390/w10010046R Core Team (2013). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Disponible en: http://www.R-project.org/.UNEP (United Nations Environment Programme). (2011). Water: Investing in Natural Capital. UNEP, Towards a Green Economy: Pathways to Sustainable Development and Poverty Eradication, Nairobi