Increases in water color cause problems for the drinking water suppliers.
Lakes and rivers are the source of drinking water for most people in Norway, Sweden and Finland. Presently, climate change is posing a threat for the quality of drinking water sources. In recent years, concentrations of dissolved organic matter (DOM) in lakes and rivers have increased and associated with this, surface waters have become browner. This poses a major challenge to drinking water providers, as removal of DOM is a key step in drinking water treatment.
Both climate and atmospheric deposition are likely to blame for the brownification of surface waters. Brownification is expected to continue under climate change, but to what extent is unclear. Adaptation measures needed are likely to raise costs of water treatment and require long-term investments. In order to maintain good drinking water quality in the future, municipalities and other stakeholders urgently need science-based projections of raw water quality under climate change as well as information about the possibilities for, and costs of adaptation.
The main aim of the DOMQUA project was to predict future DOM concentrations and color of raw water sources under climate change and to assess how to adapt drinking water facilities in the Nordic countries need to adapt to these future conditions. The scientific participants in DOMQUA have strong expertise in understanding and modelling of DOM in catchments, lakes and rivers, and in studying effects of climate change and treatment technology on quality of drinking water sources and treated drinking water. Also, social scientists will be involved to make a socioeconomic analysis of adaptation in collaboration with natural scientists and stakeholders.
Funding Nordforsk (under the Nordic Council of Ministers) has financed the research project “DOMQUA” under the The Top-level Research Initiative, the programme on ‘Effect studies and adaptation to Climate Change’. Research partners include Norwegian, Swedish and Finnish research institutes and universities, while stakeholders are several drinking water facilities and national branch organisations.