SETAC 2013: Europe Annual Meeting

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LCA as a decision support tool in the urban water system of
Aveiro (Portugal)

A.C. Dias, University of Aveiro / Department of Environment and Planning CESAM;

D. Lemos, University of Aveiro;

X. Gabarrell, Universitat Autònoma de Barcelona;

L. Arroja, University of Aveiro.

LCA as a decision support tool in the urban water system of Aveiro (Portugal)

Extended Abstract

The objective of this study is to assess the environmental
impacts associated with the urban water system of Aveiro municipality
(Portugal) using Life Cycle Assessment (LCA), in order to identify the
stages and processes with the higher environmental impacts and to
propose improvement scenarios. The whole water system was
considered, including the following stages: water catchment and
treatment, water distribution and sewage, wastewater treatment and
water administration. The production of chemicals, fuels and electricity
consumed in theses stages is also considered, as well as the
environmental impacts from deposition both in landfill and agricultural
soils of the waste generated in wastewater treatment. The transportation
of chemicals and fuel consumption by the vehicle fleet of the
administration are also considered, as well as the production of ducts
used in water distribution and sewage collection. Data on the inputs and
outputs of the water system stages refer to the year 2008 and were
mostly obtained directly from the entities responsible for their
management. The impact assessment method used is the hierarchist
approach of ReCiPe. The results show that the stage of water catchment
and treatment was the most relevant for the majority of the impact
categories, because most of the electricity consumption happened in this
stage. For marine eutrophication and marine ecotoxicity, the stage of
wastewater treatment carried alone almost all the burden, due to the
release of nitrogen and phosphorus in the sea. Moreover, no stage could
be regarded as irrelevant (including water administration). The
environmental performance of the system could be improved by
adopting some measures, such as installation of units for nitrogen and
phosphorus removal in the wastewater treatment stage, reduction of
electricity demand by improving the efficiency of pumps and other
electrical equipment, decrease of water losses in the water distribution
system, reduction of water demand, decrease of water inputs to the
sewage collection system, and use of solar or other green energy for the
pumping systems and for the other equipment that consume electricity.
The proposed improvement measures are a basis for the decision making
process regarding future investments by local authorities towards
environmental sustainability of the urban water system