The Use of Frontier Analysis to Assess the Technical Rigor of Water Loss PI’s – Alan Wyatt
The American Water Works Association (AWWA) has developed and disseminated advanced methods and performance indicators for assessing and reducing water losses in North America, based in large part on the methods and indicators developed by the International Water Association (IWA). However, many utilities and regulators still use the old, inaccurate, %NRW indicator. A robust, quantitative assessment of the technical rigor of water loss indicators was needed but could not be found in the literature. So, an innovative approach was developed, using Frontier Analysis which provided such a score of “technical rigor”. This paper presents this method, applied to three datasets from North America, assessing 15 candidate indicators for total water losses, apparent losses and real losses. The results provide quantitative “scores” of the technical rigor of the candidate indicators. Indicators with relatively high scores align with indicators used in the IWA best practices. Other indicators, such as the %NRW indicator, were found to have low technical rigor. The conclusion of the paper summarizes the rigorous indicators, and suggests areas for further application of this method, and for further research.