The quality of the water in our rivers, lakes and groundwater is increasingly coming under threat, not only by industry but also by the general pollution of our environment. Since in many parts of Europe river water and lake is the source for our drinking water, treatment plant operators are faced with the more and more difficult task of determining the quality and deciding whether to use it or not. At the other hand, wastewater treatment plants have to apply more scrutiny on the water quality of their outlets. Finally, increasing public awareness puts pressure on public and administration authorities to provide comprehensive and timely information on the state of the rivers and the expected development.
Operators at treatment plants have to manage large amounts of data, from on-line sensors and from laboratory analyses. Distributed sensor networks covering a complete river basin make this task even more difficult. There is a strong need for appropriate methods and tools to achieve a clear assessment of the current state of the water quality, to quickly detect major pollution events and to assess trends of the water quality, both short and long term.

We face the need for monitoring all these factors remotely and the fact that many people have a different view of how these data are going to be presented.

This gives the need for a flexible monitoring system that is able of accessing data on the Internet, and displaying the same data with more than one Graphical User Interface layout.

The system should fulfil the requirements listed below:

• Robustness.
  The network must be able to cope with problems that may arise without breaking down.
• Distributed Computing (DC).
  Several hardware units co-operate to achieve a common goal. This ensures flexibility and sharing of resources and functionality.
• Scaleable.
  Allows the application to expand in both functionality and number of modules. This ensures that the lifetime of the application is prolonged and that new modules can be added at any time.
• Regional grouping.
  Applications are restricted to their own region. If they want to access data from another region it activates a public relation module administering that region. This ensures that only data made available in this region will be public outside the region.
• Security.
  It should be possible to classify data into several security levels to ensure that only authorised access is granted to classified data. Data must be classified with respect to both domain and groups.
• Ease of implementation.
  The network functionality should be easy to implement and integrate in the modules.
• Operating System (OS) independence
  Ensures that modules can communicate with modules on other OS.
• Internet capabilities.
  It should be possible to access selected data from the application using an Internet browser. This ensures that independent authorities and public can access data.

How is EM²S implemented?

The definition of an EM²S Agent is: