Methodology for determining life-cycle environmental impacts due to material and energy flows in wastewater pipeline networks: A case study of Oslo (Norway)

Abstract

Any saturated urban wastewater pipeline network has an ageing mix of pipelines of different lengths, diameters and materials of construction. Each of these pipe-lengths has its own life-cycle which encompasses the material production and pipe fabrication, installation, operation and maintenance during the use phase, rehabilitation and repair and finally retirement from service. An analysis of the inflows of materials and energy into the network and the corresponding outflows, facilitates the determination of the environmental impacts associated with the life-cycle stages of the pipeline network, and an examination of how the contributions of each of these phases to the whole, changes as the network ages and progresses towards saturation. The forecast of the future flows of materials which again, is highly interlinked with the historic flows provides insight into the likely future environmental impacts. The authors, in this paper, present a general methodology which can be applied with some tailor-making, to the analysis of any wastewater pipeline network in general. The methodology is then applied to the pipeline network in the city of Oslo, and the results thereof presented towards the end of the paper.