Oil spills are serious environmental issues that potentially can cause adverse effects on marine ecosystems. In some marine areas, like the Baltic Sea, there is a large number of wrecks from the first half of the 20th century, and recent monitoring and field work have revealed release of oil from some of these wrecks. The risk posed by a wreck is governed by its condition, hazardous substances contained in the wreck and the state of the surrounding environment. Therefore, there is a need for a common standard method for estimating the risks associated with different wrecks. In this work a state-of-the-art model is presented for spatial and stochastic risk assessment of oil spills from wrecks, enabling a structured approach to include the complex factors affecting the risk values. A unique feature of this model is its specific focus on uncertainty, facilitating probabilistic calculation of the total risk as the integral expected sum of many possible consequences. A case study is performed in Kattegat at the entrance region to the Baltic Sea to map the risk from a wreck near Sweden. The developed model can be used for oil spill risk assessment in the marine environment all over the world.

To cope with present and future challenges, a growing number of water utilities in Sweden, Europe and elsewhere initiate various forms of inter-municipal cooperations creating a new regional level of drinking water governance. In order to reach viable decisions of alternative ways forward, there is an international consensus that sustainability needs to be addressed in water supply planning, design and decision-making. There are, however, few decision aids focusing on assessing the sustainability of inter-municipal cooperations and the inter-municipal policies and interventions that regional decision-makers are faced with. This paper presents a decision support model based on a combination of cost-benefit analysis and multi-criteria decision analysis for assessing the sustainability of regional water supply interventions, including formations of inter-municipal cooperations. The proposed decision support model integrates quantitative and semi-quantitative information on sustainability criteria. It provides a novel way of presenting monetized benefits and costs, capturing utilitarian aspects of alternative interventions, with non-monetized social and environmental effects, capturing aspects based in the deontological theories of moral ethics. The model is based on a probabilistic approach where uncertainties are defined by statistical probability distributions. A case study is used to exemplify and evaluate model application in decision situations regarding regionalization, (de)centralization, source water quality and redundancy. All evaluated alternatives were expected to contribute to a slightly improved social sustainability, whereas the results were more varying in the economic and environmental domains. A structured and transparent treatment of uncertainties facilitates a better understanding of the results as well as communication between decision-makers, stakeholders and the community.