Efficiency benchmarking of wastewater service providers: An analysis based on the Portuguese case

Drivers of water utilities’ operational performance – An analysis from the Portuguese case

“…Environmental protection, as well as technical, economic and social development, and even governance models, emerge as the fundamental pillars of sustainability. Wastewater (WW) treatment and drinking water (DW) supply systems must also meet these requirements to be considered sustainable (UN -United Nations, 2005; Balkema et al, 2002;Davidson et al, 2007;van Leeuwen et al, 2012;Marques et al, 2015Dong et al, 2018;Walker et al, 2021;Amaral et al, 2022). In this regard, the present study aims to identify the relevant drivers related to the main sustainability-related operational indicators for water utilities.…”

“…Consumers pay the DW and WW treatment costs through tariffs (SP revenues), thus the SP expenditures are of critical importance addressing costs recovery. In particular, personnel and energy allocation are among the largest operating expenditures (Marques and Monteiro, 2001;Balkema et al, 2002;Davidson et al, 2007;Carvalho and Marques, 2011;Molinos-Senante et al, 2014;Castellet and Molinos-Senante, 2016;Pointon and Matthews, 2016;Dong et al, 2017Dong et al, , 2018Moreno et al, 2017;Walker et al, 2021;Amaral et al, 2022). Due to the potential to lower external energy demands, the energy produced within a SP is also an important aspect to consider (Walker et al, 2021;Amaral et al, 2022).…”

“…In particular, personnel and energy allocation are among the largest operating expenditures (Marques and Monteiro, 2001;Balkema et al, 2002;Davidson et al, 2007;Carvalho and Marques, 2011;Molinos-Senante et al, 2014;Castellet and Molinos-Senante, 2016;Pointon and Matthews, 2016;Dong et al, 2017Dong et al, , 2018Moreno et al, 2017;Walker et al, 2021;Amaral et al, 2022). Due to the potential to lower external energy demands, the energy produced within a SP is also an important aspect to consider (Walker et al, 2021;Amaral et al, 2022). Furthermore, as global water demands increase, and fresh water supplies decrease, sensible use of clean water is essential (Balkema et al, 2002;Davidson et al, 2007).…”

“…Furthermore, as global water demands increase, and fresh water supplies decrease, sensible use of clean water is essential (Balkema et al, 2002;Davidson et al, 2007). In this context, the ability to reuse treated WW (Gonzalez-Serrano et al, 2005;Hernández-Sancho and Sala-Garrido, 2009;Rodriguez-Garcia et al, 2011: andAmaral et al, 2022) and to reduce DW losses (Ferro and Mercadier, 2016;Molinos-Senante et al, 2016;and Sala-Garrido et al, 2019) is crucial. Sludge production is another issue that must be addressed in WW treatment systems (Balkema et al, 2002;Molinos-Senante et al, 2014;Castellet and Molinos-Senante, 2016;Dong et al, 2018;Henriques et al, 2020;Amaral et al, 2022), imposing costs for the SP due to sludge treatment and/or deposition by third-party entities.…”

“…In this context, the ability to reuse treated WW (Gonzalez-Serrano et al, 2005;Hernández-Sancho and Sala-Garrido, 2009;Rodriguez-Garcia et al, 2011: andAmaral et al, 2022) and to reduce DW losses (Ferro and Mercadier, 2016;Molinos-Senante et al, 2016;and Sala-Garrido et al, 2019) is crucial. Sludge production is another issue that must be addressed in WW treatment systems (Balkema et al, 2002;Molinos-Senante et al, 2014;Castellet and Molinos-Senante, 2016;Dong et al, 2018;Henriques et al, 2020;Amaral et al, 2022), imposing costs for the SP due to sludge treatment and/or deposition by third-party entities. Taking all the above issues into account, the current study considers as operational indicators for the SP four inputs (allocated personnel, energy consumption, expenditures and intake DW or WW), four desirable outputs (revenue DW or WW, treated WW, reused WW and produced energy), and two undesirable outputs (produced sludge and water losses).…”