Assessing the Energetic and Environmental Impacts of the Operation and Maintenance of Spanish Sewer Networks from a Life-Cycle Perspective

Journal of Cleaner Production

Llorach-Massana

Sanjuan-Delmás

et al. 2017

Self Cite

123

Defining sustainable cities is not straightforward. The main issues involved in urban sustainability are buildings, energy, food, green areas and landscape, mobility, urban planning, water and waste; and their improvement is promoted through different strategies. However, a quantitative method, such as life cycle thinking (LCT), is essential to evaluating these strategies. This paper reviews LCT studies related to urban issues to identify the main research gaps in the evaluation of these improvement strategies. The review identifies the main sustainability strategies associated with each urban issue and compiles articles that deal with these strategies through LCT, including environmental life cycle assessment (LCA), life cycle costing (LCC), social LCA (S-LCA) and life cycle sustainability assessment (LCSA), as well as integrated analyses with combined tools. Water, waste and buildings are the urban issues that accounted for a larger amount of studies. In contrast, a limited number of papers assessed urban planning and energy (excluding energy in buildings). Strong interrelations among urban issues were identified, most of them including water. In terms of methods, 79% of the studies exclusively applied life cycle tools (i.e., LCA, LCC, S-LCA or LCSA). Within this group, the environmental dimension was the focus of 84% of the papers. Single environmental indicators (e.g., global warming) were common in 20% of the analyses, highlighting the need to integrate more impact categories to prevent trade-offs. In the field of social and sustainability assessment, there is a need for methodological advances that foster their application in urban areas. Further research should cover the thematic and methodological gaps identified in this paper, such as developing models that assess complex urban issues, generating comprehensive LCT studies and promoting multi-indicators. Life cycle tools might benefit from revising the methodology with stakeholders to optimize the understanding and communication of life cycle results for policy-and decision-making processes.

Section: Watermentioning

confidence: 99%

Application of life cycle thinking towards sustainable cities: A review

Journal of Cleaner Production

Llorach-Massana

Sanjuan-Delmás

et al. 2017

Self Cite

123

“…The resulting wastewater generation was 87 m 3 capita −1 year −1 , which is similar to that of Betanzos and does not explain the difference in energy consumption. The length of sewer needed to connect the city to the WWTP might influence the electricity consumption as predicted by Petit‐Boix and colleagues (). Based on table , the length per m 3 of wastewater was 0.05 to 0.07 km, which does not explain the difference between the cities.…”

Section: Resultsmentioning

confidence: 95%

“…Previous analyses tried to explain general variations in the O&M of sewers (Petit‐Boix et al. ), but an analysis of specific case studies might help to delve deeper into the differences among cities.…”

Section: Resultsmentioning

confidence: 99%

“…As opposed to WWTPs, which are generally affected by climatic conditions, a particularity of sewers is the effect of urban configuration on the energy required to operate the system (Petit‐Boix et al. ). Within the existing literature, articles have mainly focused on the environmental impacts of the construction or full life cycle of sewers (Morera et al.…”

Section: Introductionmentioning

confidence: 99%

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Addressing the Life Cycle of Sewers in Contrasting Cities through an Eco‐Efficiency Approach

J of Industrial Ecology

Arnal

Marín-Navarro

et al. 2017

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Evaluating the sustainability of the urban water cycle is not straightforward, although a variety of methods have been proposed. Given the lack of integrated data about sewers, we applied the eco-efficiency approach to two case studies located in Spain with contrasting climate, population, and urban and sewer configurations. Our goal was to determine critical variables and life cycle stages and provide results for decision making. We used life cycle assessment and life cycle costing to evaluate their environmental and economic impacts. Results showed that both cities have a similar profile, albeit their contrasting features, that is, operation and maintenance, was the main environmental issue (50% to 70% of the impacts) and pipe installation registered the greatest economic capital expenditure (70% to 75%) due to labor. The location of the wastewater treatment plant (WWTP) is an essential factor in our analysis mainly due to the topography effects (e.g., the annual pump energy was 13 times greater in Calafell). Using the eco-efficiency portfolio, we observed that sewers might be less eco-efficient than WWTPs and that we need to envision their design in the context of an integrated WWTP-sewer management to improve sewer performance. In terms of methodological approach, the bidimensional nature of eco-efficiency enables the benchmarking of product systems and might be more easily interpreted by the general public. However, there are still some constraints that should be addressed to improve communication, such as the selection of indicators discussed in the article. Keywords:eco-efficiency eco-innovation life cycle assessment (LCA) life cycle costing (LCC) water cycle wastewater Supporting information is linked to this article on the JIE website Conflict of interest statement: The authors have no conflict to declare.

“…On the other hand, the trench subsystem considered the energy and materials required to install the pipe, the material transport to the construction site and the transport and final disposal of the excavated soil. The operation and maintenance stage was excluded from the analysis, given that the electricity required to pump wastewater is very variable depending on the configuration of the city and it is not possible to assign a standard value to one metre of pipe (Petit-Boix et al 2015). In addition, according to Petit-Boix et al (2014), the impacts of the diesel used to demolish the infrastructure are negligible and were not addressed.…”

Section: Definition Of the System Boundariesmentioning

confidence: 99%

Integrated Structural Analysis and Life Cycle Assessment of Equivalent Trench-Pipe Systems for Sewerage

Roigé

Fuente

et al. 2015

Water Resour Manage

Self Cite

The demand for sanitation infrastructures is increasing due to a rise in the urban population. To meet the need for wastewater collection, the construction of sewer networks must comply with a series of technical parameters that indicate whether a solution is feasible or not. Considering that this construction implies a series of environmental impacts, this study coupled a structural analysis of one linear metre of sewer constructive solutions with their life cycle impacts. Different pipe materials (concrete, polyvinylchloride (PVC) and high-density polyethylene (HDPE)) were combined with different trench designs and their environmental performance was assessed using Life Cycle Assessment (LCA). These solutions complied with technical parameters consisting of traffic loads and pavement conditions, among others. Concrete pipes embedded in granular matter result in fewer environmental impacts, such as Global Warming Moreover, the environmental impacts of this solution are similar to those resulting from the substitution of pipes that do not comply with the mechanical requirements of the construction site. Therefore, proper planning is needed to provide cities with sewers that are resilient to time and external loads and reduce the urban environmental impacts.