Drinking water production plants (in The Netherlands) are normally controlled by effluent quality. When the effluent quality does not meet the guidelines, the treatment process is manipulated. This is mainly done using the experience of the operators. Water quality models can be used to support the operators' task by off-line process evaluation and model predictive control (MPC).
Stimela is a modelling environment that is developed by DHV Water BV and the Delft University of Technology. It is especially designed for water quality modelling. An example of off-line use of Stimela for operation and design is given by a model of a counter-current packed tower aerator.
In the near future Stimela will be used for MPC. Therefore DHV Water BV and the Delft University of Technology are starting a project with water companies in which MPC with Stimela will be applied. In this project internet technology will be used to access water quality data from online measurements and form the model calculations. The data can be used by operators when they are at other locations, by drinking water technologists at the office to analyse specific problems, and by the management for weekly, monthly and yearly reports. In this way all the data are available for everyone in the organisation, from the operator to the managing director.