One issue high up the agenda of every water supply operations manager is the need to monitor the quality of the water supply. Water quality modeling software can help both in managing everyday water quality issues, such as chlorination, water source tracking, or water age identification, and to identify and monitor the presence of pollutants in the water supply whether caused by agriculture, industry or a terrorist act.
At the presentation session devoted to the Visualization of Water Quality Issues, Wallingford Software took the opportunity to demonstrate a variety of visualization tools that can be used to identify and monitor the water quality parameters in a water supply. This included a live demonstration of water quality modeling and data visualization based on a theoretical example of a terrorist attack on a water supply. To be effective, water quality modeling requires the use of modeling software capable of simulating large and detailed all-mains models with simulation times running into months not days. The IMTech demonstration reflected this by using InfoWorks WS, a water distribution modeling software designed to manage networks over 100,000 links in size with simulations times lasting weeks or months.
In the demonstration, a pollutant was injected into a water supply tank at 2AM. It took 5 hours to detect the incident; the pollutant was fed to the tank at a constant concentration between 2AM and 7AM. The following visualization tools were used to aid with water quality monitoring:
Thematic Layers Parts of town that have elevated concentration of pollutant are easily identified by coloring the nodes proportional to the concentration of a pollutant.
Contours Surfaces Using contours of the pollutant concentration one can easily identify potential pockets of polluted water after the system has been flushed.
Animated labels The use of animated labels provides a quick way to track tank outflows without the need to zoom in to an individual tank.
Multi-Attribute/Multi-Element Graphs The ability to plot different elements and attributes on the same graph allows the user to track link flow vs. node concentration.
Multi-Pipe Profiles (Long Sections) InfoWorks WS offers long sections with editable tabular views and color-coded elements; this tool helps track the pollutant spreading through key mains in the system.
Flow Totalization The ability to calculate the total volume of water flown through a pipe in the system helps one determine the total concentration of the pollutant fed in an area.
System Flushing Hydrant modeling and sedimentation calculation is curtailed for the flushing scheduling. It ensures that pollutant has been removed not only from the water but also form the sediments in the system.
3D Surfaces 3D concentration surface overlapped with aerial photos helps a laymen correlate the high pollutant concentration to the real system.
Screen Capturing Animation All result representation in InfoWorks WS is fully dynamic. The user can chose to make animated movies to facilitate data dissemination.
Sasa Tomic, VP of Product Management at Wallingford Software Inc. concluded: Water supply utilities throughout the United States fear a terrorist attack; an attack that would deliberately inject a pollutant in the water supply to harm the consumers, disrupt the supply or induce panic amongst consumers. Water quality modeling cannot prevent such situations from occurring, but can help to prepare and react to a pollution incident. Understanding the workings of your network combined with the real-time integration with SCADA makes it possible to promptly identify and trace the impact of such an incident so that effective corrective action can be taken. By modeling every hydrant in your system and using sedimentation calculation, you can ensure that the pollutant is removed quickly and effectively. We believe that water quality modeling is one of the fastest growing applications of hydraulic modeling in the United States today.