Efficient and reliable water and wastewater systems have been a major challenge for Swedish municipalities and authorities for several decades. High-performing and cost-effective treatment plants and pipe networks continuously free Swedish waterways from harmful discharges. The water and wastewater industry in Sweden has a good international reputation and competes successfully on the international market.

At IEA, our research is devoted to the automation and control of urban water systems, emphasising operation rather than design. In operation, a wide range of time frames is considered, all the way from minutes to years, and dynamic rather than static characteristics are essential. Operational behaviour thus becomes part of the life cycle analysis. One of the functions is the control of individual processes. Another - and an increasingly important one - is the interaction between individual processes, facilities and systems. This aspect of coordinated operation and control is a key technology if today's systems are to be transformed into sustainable ones.

Automation and control can be considered as part of the vast field of systems analysis. Any urban water system, traditional or future, will almost certainly be characterised by constantly changing operating conditions. This has to do with the influence of the users of the system. Automation and control will deal precisely with this impact. The operational aspects will become increasingly important, as they will affect not only the costs of energy, transport, chemicals and other consumables, but also the environmental impact of the constantly changing conditions.

Keywords: wastewater treatment, modelling, simulation, sedimentation, digestion, greenhouse gases.