Francisco Silva Pinto

A multi-objective approach with soft constraints for water supply and wastewater coverage improvements

In Brazil, due to public health, social and economic cohesion problems, access to water and wastewater services is certainly one of the main concerns of the different stakeholders in the Brazilian water sector. But as the focus is mainly on the expansion and building of new infrastructures, other features such as the robustness and resiliency of the systems are being forgotten. This reason, among others, highlights the importance of sustainable development and financing for the Brazilian water sector. In order to assess that goal, a multi-objective optimization model was built with the aim of formulating strategies to reach a predefined coverage minimizing time and costs incurred, under specific hard and soft constraints, assembled to deal with key sustainability concepts (e.g., affordability and coverage targets features) as they should not be left apart. For that purpose, an achievement scalarizing function was adopted with three distinct scaling coefficient vectors for a given reference point. To solve this combinatorial optimization problem, we used a mixed integer-linear programming optimizer that resorts to branch-and-bound methods. The work developed, paves the way toward the creation of a decision-aiding tool, without disregarding the number of steps that need to be taken to achieve the proposed objectives.

Water services performance: do operational environment and quality factors count?

Abstract Decision makers must keep in mind that water services have an invaluable ‘price’ for the public budget and society’s welfare. However, due to the specific features of the service, water utilities are prone to inefficiency. Thus, performance evaluation becomes indispensable to face this constraint. Besides the application of the traditional technique of Data Envelopment Analysis to evaluate the performance of Portuguese water utilities, this study also implements the robust technique of order-m to assess the influence of operational environment on water utilities’ performance. In spite of several reforms, the Portuguese water sector still reveals significant levels of inefficiency, partially caused by an inappropriate operating scale. Concerning the operational environment, it was possible to observe a positive influence of private sector participation, economies of scope, and groundwater sources on efficiency. The influence of the ‘quality of service provided’ was also studied in this performance analysis.

Tariff Suitability Framework for Water Supply Services

Water supply (WS) tariffs have evolved significantly in the past decades, although in a varying fashion around the world. Indeed, this development is linked to increasingly demanding requirements, or objectives that have to be achieved by water utilities (e.g., stricter quality standards and infrastructure maintenance levels, cost recovery, social concerns and environmental protection demands). The perception of WS tariffs as a powerful management tool, subject to context dependent objectives, raises the concern on how utilities prioritize them. This hierarchy is desirable due to the possible conflicting nature of objectives. From that point of view, and on the basis of protecting the public interest, the fitness between objectives set by the utilities and actual needs may require a broader institutional approach. The need for regulatory activity may be required in the context of too much arbitrariness in tariff setting procedures. For this objective, a regulatory tool is set, based on multicriteria decision analysis (MCDA) modeling methods, to provide a requisite framework capable of considering the multiple dimensions of WS tariffs and the assessment of specialists, practitioners and other legitimate stakeholders in the ‘tariff setting’ decision making process. The specified tariff suitability framework (TSF) will work as a regulatory tool, taking into account the utilities’ particular context and background factors. The outcomes allow to determine the tariff suitability and to build tailored policy recommendations, which are critical aspects for a sound regulation.