This study examines the subsurface infrastructure in the Swedish city of Norrköping from an urban mining perspective. Urban mining is a broadly defined term for different strategies that regard the built environment as a resource base for materials. In this study, the focus is on three base metals that exist in large quantities in infrastructure parts: iron, copper and aluminium. A special focus is given to the parts of Norrköping’s infrastructure that are not in-use and thus constitute a ”hibernating stock” that contains recyclable metals. The main results of this study are twofold. First, a quantitative assessment of the hibernating stocks of urban infrastructure gives answers to how large the stocks are and where in Norrköping they are located. This was performed using a spatially informed Material Flow Analysis to arrive at a recycling potential in terms of weight and spatial concentration. Second, a qualitative assessment was made regarding how these hibernating stocks of urban infrastructure come into existence. An infrastructure studies perspective was used to outline three patterns with their own sets of ”hibernation” logics. These logics give rise to different prerequisites for the implementation of urban mining in practice. A main argument of this study’s cover essay is that both of the above outlined kinds of knowledge are needed to engage in urban mining with confidence. Thus, the main focus of the cover essay text is to describe how the two different perspectives of Material Flow Analysis and infrastructure studies were combined into a coherent research approach.

This PhD thesis concerns urban mining, an umbrella term for different recycling strategies aimed to recover materials from the built environment. More specifically, it focuses on hibernating urban infrastructures, that is: cables and pipes that have been left behind in their subsurface location after they were disconnected. I term this subsurface urban realm of system rejects the “Urk World”. “Urk” is short for “urkopplad”, the Swedish word for “disconnected”, an abbreviation often found on old infrastructure maps denoting discarded system parts. Since urks contain high concentrations of copper, my normative stance is that the Urk World should be “mined” as a contribution towards diminishing the persistently wasteful handling of mineral resources in society. The thesis has three focus areas. The first of these discusses how the Urk World has emerged, that is: how the creation of urks is sustained in sociotechnical processes related to infrastructure’s provision. The second concerns the potential of urk mining, how much copper the Urk World contains, where these quantities are located and by which implications they could be recovered. The third focus area is devoted to the politics of urks, and is concerned with the political embeddedness of infrastructure and where politics might intervene for the sake of increased urk recovery. Five papers complete the thesis. The first paper investigates how much copper, aluminium and steel there is in the Urk World of the Swedish city of Norrköping, and how these quantities are spatially dispersed in the urban environment. The second paper is based on interviews with system owners and repair crews, and investigates how urks come into existence in relation to three different infrastructural processes: maintenance, larger installation projects and shutdown. The third paper describes how environmental systems analysis can be beneficially coupled with theories and methods from the social sciences to create knowledge useful to aid the development of urk recycling schemes. The fourth article makes use of the inherent ambiguities of urks to investigate a spectrum of locations where politics aimed for increased urk recovery can intervene as well as what is at stake there. The fifth and final paper investigates urks in Linköping’s power grid in spatial and weight terms, and analyses the implications of urk recovery from several different viewpoints. In overall terms, the major contribution of the thesis is how it improves the knowledge of societal stocks of materials, thereby giving an increased recognition of the built environment as a resource base. In overall scientific terms, it sets an example of how a coherent interdisciplinary research design can provide knowledge useful for the implementation of urk recycling schemes as well as for political decision–making for increased urk recovery.