SCATTERGRAPH PRINCIPLES AND PRACTICE Evaluating Pump Stations, Inverted Siphons, and Other Related Structures

The scattergraph is a graphical tool that provides insight into sewer performance through a simple and intuitive display of flow monitor data. This tool can also be extended to evaluate the performance of pump stations, inverted siphons, and related structures under certain conditions. A flow monitor located upstream from a pump station, inverted siphon, or other structure can provide important information about their operating characteristics. This information is revealed any time a flow monitor operates within backwater conditions influenced by these structures. The addition of iso-Q lines to a scattergraph allows the actual performance of pump stations, inverted siphons, and other structures to be compared to anticipated performance. Practical examples from flow monitor locations throughout the United States are provided, demonstrating the scattergraph signatures of approach conditions to pump stations, inverted siphons, and other structures under various conditions.