A comprehensive eco-efficiency analysis of wastewater treatment plants: estimation of optimal operational costs and greenhouse gas emissions.

Producción CientíficaThe transition to a neutral carbon and sustainable urban water cycle requires improving eco-efficiency in wastewater treatment processes. To support decision-making based on eco-efficiency evaluations, reliable estimations are fundamental. In this study, the eco-efficiency of a sample of 109 WWTPs was evaluated using efficiency analysis tree method. It combines machine learning and linear programming techniques and therefore, overcomes overfitting limitations of non-parametric methods used by past research on this topic. Results from the case study revealed that optimal costs and greenhouse gas emissions depend on the quantity of organic matter and suspended solids removed from wastewater. The estimated average eco-efficiency is 0.373 which involves that the assessed WWTPs could save 0.32 €/m3 and 0.11 kg of CO2 equivalent/m3. Moreover, only 4 out of 109 WWTPs are identified as eco-efficient which implies that the majority of the evaluated facilities can achieve substantial savings in operational costs and greenhouse gas emissions.Junta de Castilla y León - UE-FEDER (CL-EI-2021-07

Productivity change and its drivers for the Chilean water companies: a comparison of full private and concessionary companies

The privatization of the water industry has aroused interest in comparing the performance of public vs. private water companies. However, little research has been conducted to compare the performances of full private (FPWCs) and concessionary water companies (CWCs). This study estimates and compares the productivity growth and its drivers (efficiency, technical and scale change) for a sample of Chilean FPWCs and CWCs over the 2007–2015 period using the input distance function. Both types of water companies showed deteriorations in productivity growth, with CWCs exhibiting higher rates of negative productivity growth than FPWCs. For FPWCs, any gains in efficiency and scale were outstripped by negative technical change. CWCs did not improve their performance in any of the three components of productivity change. The comparison of productivity change between FPWCs and CWCs is essential to support decision-making therefore, this study is of great interest for policymakers worldwide who are developing policies aimed at privatizing water companies

Price-cap regulation in the English and Welsh water industry:a proposal for measuring productivity performance

Privately owned water utilities typically operate under a regulated monopoly regime. Price-cap regulation has been introduced as a means to enhance efficiency and innovation. The main objective of this paper is to propose a methodology for measuring productivity change across companies and over time when the sample size is limited. An empirical application is developed for the UK water and sewerage companies (WaSCs) for the period 1991-2008. A panel index approach is applied to decompose and derive unit-specific productivity growth as a function of the productivity growth achieved by benchmark firms, and the catch-up to the benchmark firm achieved by less productive firms. The results indicated that significant gains in productivity occurred after 2000, when the regulator set tighter reviews. However, the average WaSC still must improve towards the benchmarking firm by 2.69% over a period of five years to achieve comparable performance. This study is relevant to regulators who are interested in developing comparative performance measurement when the number of water companies that can be evaluated is limited. Moreover, setting an appropriate X factor is essential to improve the efficiency of water companies and this study helps to achieve this challenge

Implications of Denmark\u27s Water Price Reform for Reverine and Coastal Surface Water Quality

Article 9 of the EU’s Water Framework Directive suggests that Member States should provide “adequate incentives” for efficient use of water resources. Although the Directive is mainly about protecting the ecological quality of water bodies, control of quantity serves as an “ancillary element” in delivering on the objectives. Despite their financial difficulties, Member States have been slow to bring their policies on water pricing up to the wording and 2010 deadline of the Directive’s article 9. This Article explores the significance of water pricing reform for the ecological quality objectives for surface waters and, as a stepping stone in this analysis, for water resource efficiency. It does so with a catchment-based analysis of implications from water pricing reform introduced in the early 1990s in Denmark. Household water use is found to have been 50% higher per capita before the reform, which introduced full-cost pricing and a water supply tax. Good data availability for the catchment allows the analysis to demonstrate estimates for the improvements in water flows as well as for a specific water quality parameter. Despite the significant reduction in water demand, the main river is affected only at the margin. For smaller streams and brooks, however, there are more notable impacts for water quality and with potential benefits for rare species dependent on clean waters. A small reduction in emission loadings to coastal waters has comparatively high economic value. The Article finds that water pricing has an important role to play for future management

Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty

[EN] The regulation of water services shares many similarities with that of other utilities such as electricity or telecommunications. As a result, similar methods are often used by regulators to assess the efficiency of companies in those sectors. Data Envelopment Analysis (DEA) is one of those widely applied methods. This paper aims to determine the adequacy of DEA as a regulatory tool for urban water services, with a special focus on the quality of the available data. In order to obtain useful conclusions, two DEA simulations were performed with audited data from 194 water utilities, officially made available by the Portuguese water regulatory authority (ERSAR). Both simulations will demonstrate that the inherent inaccuracies found in some of the key data provided by water utilities represent a significant obstacle to obtain meaningful results with the DEA technique. This could represent a paradigm shift for some of the regulatory authorities currently using DEA or similar techniques, as the complexity of the method does not seem to be justified by a better analysis of the comparative performance of the different services.Cabrera Rochera, E.; Estruch-Juan, ME.; Molinos-Senante, M. (2018). Adequacy of DEA as a regulatory tool in the water sector. The impact of data uncertainty. Environmental Science & Policy. 85:155-162. https://doi.org/10.1016/j.envsci.2018.03.028S1551628

Evaluation of the impact of separative collection and recycling of municipal solid waste on performance: An empirical application for Chile

The collection of municipal solid waste (MSW) is a public service with notable effects on the environment and public health. The objective of this study was to evaluate the impact of selective collection and recycling of MSW on the performance of municipalities in providing MSW services. By employing the data envelopment analysis method, the efficiency and eco-efficiency scores for a sample of 298 municipalities in Chile were analyzed and compared. The efficiency estimation focused on the economic performance of the municipalities in the provision of MSW services, whereas the eco-efficiency assessment also integrated the environmental performance. The results indicated that the selective collection and recycling of MSW had a significant impact on the performance of the municipalities in providing these services. The percentages of efficient and ecoefficient municipalities were very low (4.70% and 4.36%, respectively), thus demonstrating the large room for performance improvement by Chilean municipalities in the management of MSW. The efficient and eco-efficient municipalities were heterogeneously distributed throughout the country, revealing the lack of collaboration between municipalities at the regional level. Finally, exogenous variables to the management of MSW carried out by the municipalities, including the population served, population density, tourism and waste generated per capita, all had an impact on the efficiency and eco-efficiency scores. The results and conclusions of this study are of great relevance for policy makers at the regional and local levels to improve the management of MSW in the context of a circular economy

Evaluación de la eficiencia de la Superliga de Voleibol 2013/14

La eficiencia, entendida como la relación entre inputs y outputs, ha sido evaluada para numerosos deportes como el fútbol, baloncesto, tenis o béisbol. Sin embargo, en el ámbito del voleibol no se han realizado estudios de este tipo. Por ello, en este trabajo se evalúa la eficiencia de los equipos masculinos y femeninos de la Superliga española de voleibol. A nivel individual, se evalúa la eficiencia de los jugadores (masculinos y femeninos) de voleibol diferenciando entre posición defensiva y ofensiva. Para ello, se hace uso de un modelo análisis envolvente de datos radial bajo orientación output y rendimientos constantes a escala. En un análisis de segunda etapa se verifica que no hay diferencias estadísticamente significativas en la eficiencia de los jugadores internacionales y no internacionales. Así mismo, se puede concluir que dentro de las posiciones defensivas, los jugadores/as líberos son más eficientes que los receptores. Por el contrario, en las posiciones ofensivas (central, opuesto y atacante) las diferencias de eficiencia no son significativas

Profit, productivity and price performance changes in the water and sewerage industry:an empirical application for England and Wales

This paper aims to analyse the impact of regulation in the financial performance of the Water and Sewerage companies (WaSCs) in England and Wales over the period 1991–2008. In doing so, a panel index approach is applied across WaSCs over time to decompose unit-specific index number-based profitability growth as a function of the profitability, productivity and price performance growth achieved by benchmark firms, and the catch up to the benchmark firm achieved by less productive firms. The results indicated that after 2000 there is a steady decline in average price performance, while productivity improves resulting in a relatively stable economic profitability. It is suggested that the English and Welsh water regulator is now more focused on passing productivity benefits to consumers, and maintaining stable profitability than it was in earlier regulatory periods. This technique is of great interest for regulators to evaluate the effectiveness of regulation and companies to identify the determinants of profit change and improve future performance, even if sample sizes are limited

Cost and quality of service performance in the Chilean water industry: A comparison of stochastic approaches

Producción CientíficaThe evaluation of efficiency can be of great value to water companies and regulators to adopt policies and design incentives to enhance performance. This study delves into the implications of employing distinct methodologies, namely the classical Stochastic Frontier Analysis (SFA), Bayesian SFA, and Stochastic non-parametric Envelopment of Data (StoNED), to evaluate cost and quality of service efficiency within the water industry. Chilean water companies reported average efficiencies of 0.623, 0.583, and 0.522 using the SFA, BSFA, and StoNED approaches, respectively. Furthermore, the SFA analysis suggested that the performance of water companies experienced a decline of −0.59% per year from 2010 to 2018. In contrast, the BSFA and StoNED estimations indicated an opposite trend, with annual performance improvements of 0.51% and 0.17% respectively, over the same period. These findings underscore the critical role of selecting appropriate methodologies when interpreting and comparing efficiency results for making informed long-term decisions

Carbon efficiency analysis in the provision of drinking water: Estimation of optimal greenhouse gas emissions

Producción CientíficaAssessing carbon efficiency (CE) in the provision of drinking water services is essential to achieve a net-zero greenhouse gas (GHG) urban water cycle. Previous studies evaluating the CE of water companies are very scarce and employed parametric and non-parametric. Both methodological approaches present limitations such as overfitting issues or require assumptions about the production technology which could lead to less reliable efficiency scores. To overcome these limitations, in this study, and for the first time, we estimated CE of English and Welsh water companies using the Efficiency Analysis Trees (EAT) approach. This technique brings together machine learning and non-linear programming techniques to estimate production frontier and efficiency scores. It also allowed us to quantify the optimal level of GHG emissions in the provision of water services and estimate potential GHG savings. Bootstrap truncated regression methods were employed to quantify the impact of operating characteristics on CE of water companies. The optimal level of GHG emissions was estimated to be between 0.062 and 133.03 tons of CO2 equivalent (CO2eq) per year and per connected property. The average CE was at the level of 0.632. This means that GHG emissions could reduce by 36.8% to maintain the same level of water services. Equivalently, this corresponds to a reduction of 488,321 tons of CO2eq per year. Water only companies exhibited a better performance than water and sewerage companies with an average CE of 0.785 and 0.540, respectively. The performance of the English and Welsh water companies decreased over time. In 2011 the average CE was 0.772 whereas it went down to 0.534 in 2020. It was also estimated that on average water companies could reduce 0.034 tons of CO2eq per cubic meter of drinking water supplied and 16.16 tons of CO2eq/ connected property per year. The regression results showed that topography and water treatment complexity had a significant impact on CE. The conclusions of this study are relevant for policy makers to define policies toward a low-carbon urban water cycle