ÖKOPOLIS – Urban Resource Management

Project goal

The objective was to survey and assess diffuse metal emissions and develop a pollutant management based on ecologically sustainable development. By means of the methodology of Material Flow Analysis, the employment of building materials containing zinc, copper, lead and aluminium and diffuse emissions of the most important applications have been accounted in a representative housing settlement. The most important application areas are building coverings, sanitary installations, outside facilities (e.g. fences) and supply networks.

Summary

Since several decades the metabolism of cities is investigated in terms of inputs and outputs of materials and energy in order to derive policies for minimising the impact on the environment and human health. In Vienna, for instance, the phenomenon of the accumulation of materials was quantified: in total, per inhabitant 350 tonnes of solid materials are accumulated in 1991. This stock of resources increases by 1-3 % per year. Due to this continuous augmentation the potential of material recovery, but also the impact of emissions resulting from the use of accumulated resources is rising. These emissions emanate from many, partially hardly identifiable and widespread sources and are therefore called nonpoint emissions or diffuse emissions.

Diffuse emissions are also subject of investigations in other urban areas: Substance balances have been accounted in Amsterdam and Stockholm in order to reduce the metal loading of marine sediments. A major action developed from these balances was the reduction of diffuse emissions by limiting the use of exposed metallic building materials (e.g. zinc and copper roofing). A study on behalf of the European Commission on pollutants in waste water and sewage sludge concludes that copper and zinc should be included in the list of priority substances in the field of water policy and proposes to take actions at the biggest sources of emissions particularly at diffuse sources. These studies have motivated the city of Vienna to investigate this topic more in detail and develop actions. 

Material balances have been used successfully for deriving compatible loads, for early detection of environmental problems and as a basis for developing a pollutant management. The study provides systematic information of the potential for diffuse emissions of metallic building materials. Environmental product declarations and eco labels have to consider the potential for diffuse emissions in order to protect the quality of the environment (surface water, ground water, sediments, soil, indoor air, etc.).