Measures to achieve improved hygienic water quality for recreational activities in storm runoff water and city rivers – pre-project to identify research needs

Summary

This report deal with the hygienic water quality of the rivers in Oslo, and describes the possible health risk related to exposure to this water during recreational activities. The occurrence of infectious virus, bacteria and parasites from fecal sources of pollution is considered to constitute the greatest health related risk. Thus, it is important to focus on measures to reduce the sources and concentrations of fecal pollution to urban water bodies where there are many people, and to include measures to prevent people from being exposed to the water at sites or times when the water has a high level of fecal pollution. The report also describes the methods to identify the sources of fecal pollution (Microbial source tracking), rapid methods to monitor hygienic water quality, and knowledge about the effect of natural treatment systems. There is an anticipation that the restauration of urban rivers will restore many ecosystem services, where better water quality is one of the mostly esteemed, in addition to flood reduction, increased biodiversity, aesthetics and more. It would be appropriate to look at all aspects related to water quality and how to succeed with restauration of a multi-use urban river where good water quality is one of the goals in a follow up project. This report identifies the knowledge gaps and suggests topics for further research in connection to restoration of urban rivers where the purpose is to enhance the water quality.