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- Are municipal waste utilities becoming sustainable? A framework to assess and communicate progressPublication . Fernández Braña, Álvaro; Sousa, Vítor; Ferreira, CéliaA framework of indicators to assess the progress towards sustainability of municipal waste management utilities is developed. Its purpose is to fulfil the need for assessing the performance of municipal waste (MW) management in a simple but comprehensive way—unlike indicators based on individual aspects such as recycling—and including aspects not well considered before, such as waste prevention. The framework is composed of a set of six single indicators, concerning the three dimensions of sustainability: reduction of effectively landfilled MW and reduction of MW generation (environmental component), balance between expenses and revenues and reduction of costs (economic component), accessibility to separate collection and number of complaints (social component). Each indicator consists of an evaluation of the current status of the variable in contrast to a previous situation, with a positive value in case of improvement or negative in case of decline. Then, the values of the individual indicators are combined to obtain a global result. This approach focuses on dynamic progress towards sustainability, complementing the common static indicators. Contrarily to the existing performance indicator schemes, the proposed framework aims at measuring the progress and not the absolute or relative achievement of a waste management utility. The framework was tested on two Portuguese municipalities, proving to be a straightforward application and reliable in guiding stakeholders. Results for the case study showed good performance on economic sustainability, while environmental and social performance were lower due to a lack of strategies for waste prevention and low source separation, affected by poor accessibility to separate collection.
- Looking beyond the banning of lightweight bags: analysing the role of plastic (and fuel) impacts in waste collection at a Portuguese cityPublication . Fernández Braña, Álvaro; Feijoo, Gumersindo; Ferreira, CéliaThe purpose of this work is to assess the environmental impacts of the collection of mixed municipal solid waste (MSW) in a selected neighbourhood of the Portuguese city of Aveiro. To this purpose, the main elements necessary for the collection process (carrier bags, dustbins, street containers and vehicles) were analysed applying the life cycle assessment methodology, making use of locally gathered data. The main impacts associated with this activity are mostly related to the use of polyethylene plastic bags to carry the waste from the household to the waste container, and to the fuel consumption of collection vehicle that picks MSW from street containers and transports it to the treatment facility. The impacts associated with the plastic bags were primarily due to their disposal in a sanitary landfill after use and secondarily to the consumption of fossil raw materials required for their production. Given the relative high impact of the plastic bags, alternative scenarios were tested: using bags entirely produced with recycled polyethylene and bags produced with bio-based plastics derived from starch (TPS) and from wastewater (PHA). PHA bio-based bags were found to perform slightly better than conventional high-density polyethylene (HDPE) bags, but HDPE bags with 100% recycled content remained as the environmentally best option. A sensitivity analysis was performed to check the influence of bag size. Regarding the fuel consumption by collection vehicles, a comparison was performed to check how sitespecific conditions can influence the impact of this activity, resulting in remarkably higher consumptions when local data were used instead of reference databases.
- The setting up of a pilot scale pay-as-you-throw waste tariff in Aveiro, PortugalPublication . Ferreira, Célia; Neves, Anita; Fernández Braña, ÁlvaroOver the last 20 years solid waste has become an important issue in municipalities and counties and a problem for societies aspiring to economic, social and environmental sustainability. The new, recently approved Waste Framework Directive and Landfilling Directive have even higher targets related to municipal waste recycling and landfilling, and critical changes need to take place if European targets are to be realistically achieved. Pay-as-you-throw (PAYT) waste tariffs are an instrument that can help achieving recycling targets. PAYT works by linking the payment of a waste-collection tariff with the amount of waste discarded so that the payment increases when more waste is produced: “the more one discards, the more one pays”. This work shows the early stages of PAYT implementation in pilot scale in a municipality in Portugal. The changes carried out in the collection infrastructures are described, as well as other complementary measures that were simultaneously implemented, namely reinforcement of the collection of dry recyclables and promotion of home composting.
- Benchmarking operational efficiency in waste collection: discussion of current approaches and possible alternativesPublication . Sousa, Vítor; Ferreira, Célia; Fernández Braña, Álvaro; Meireles, I.Efficiency assessment and benchmarking are crucial for managing any organization. However, especially from a regulatory perspective, such efficiency assessment and benchmarking must be unbiased from context-specific issues and should provide an absolute rating, rather than a relative one. The current work reviews the approaches used for performance assessment and benchmarking waste collection services, revealing that the majority are biased and are not absolute, and proposes two alternative context-unbiased and absolute performance indicators, the collection capacity use (CCU) and the segregated waste collection efficiency (SWE). The proposed indicators were calculated for 246 utilities operating in Portugal. The utilities were then ranked accordingly, and their position was compared with the position attained using the equivalent performance indicators in the system currently in use by the Portuguese service regulator. The results reveal ranking differences of over 50 positions and illustrate how misleading the results from context-biased and relative metrics can be.
- Development of indicators to monitor environmental impacts of the transition to PAYT tariffsPublication . Fernández Braña, Álvaro; Ferreira, Célia
- Socioeconomic indicators to monitor the impacts of the transition to PAYT tariffsPublication . Dinis, Isabel; Petrillo, Tupac; Castro, Fátima Velez de; Ferreira, Célia; Proença, Sara; Fernández Braña, Álvaro; Neves, Anita