Constituent Alternatives

The Constituent Alternative contains the water quality data used to model a constituent concentration throughout the network when performing a water quality analysis.

Selecting a constituent from the Constituent drop-down list provides default values for table entries. This software provides a user-editable library of constituents for maintaining these values, which may be accessed by clicking the Ellipsis (...) next to the Constituent menu.

The following attributes can be defined in the Constituent alternative:

Concentration (Initial) - The concentration at the associated node at the start of an EPS run.
Concentration (Base) - The concentration of the inflow into the system at the associated node. If there is no inflow, then this flow does not affect constituent concentration.
Mass Rate (Base) - The mass per unit time injected at a node when the constituent source type is set to "Mass Rate".
Constituent Source Type - there are four ways in which you can specify a constituent entering a system:
- A concentration source fixes the concentration of any external inflow entering the network, such as flow from a reservoir or from a negative demand placed at a junction.
- A mass booster source adds a fixed mass flow to that entering the node from other points in the network.
- A flow paced booster source adds a fixed concentration to that resulting from the mixing of all inflow to the node from other points in the network.
- A setpoint booster source fixes the concentration of any flow leaving the node (as long as the concentration resulting from all inflow to the node is below the setpoint).
Pattern (Constituent) - The name of the constituent pattern created under Component > Patterns that the constituent will follow. The default value is "Fixed".
Is Constituent Source? - This attribute should be set to True if the element is to be a source in the scenario. Setting it to False will turn off the source even if there are values defined for Concentration (Base) or Mass Rate (Base).

The following buttons are available:

Selection Set	Opens a submenu containing the following options: Create Selection Set—Allows you to create a new selection set. Add to Selection Set—Adds all of the elements in the current tab of the alternative to a previously created selection set that you specify. Remove from Selection Set——Removes all of the elements in the current tab of the alternative from a previously created selection set that you specify.
Select in Drawing	Opens a submenu containing the following options: Select in Drawing—Selects the elements in the current tab of the alternative in the drawing pane. Add to Current Selection—Adds all of the elements in the current tab of the alternative to the group of elements that are currently selected in the Drawing Pane. Remove from Current Selection—Removes the elements in the current tab of the alternative from the group of elements that are currently selected in the Drawing Pane. Select Within Current Selection—Selects the element or elements that are both in the current tab of the alternative and are already selected in the Drawing Pane.
Report	Generates a report containing the data within the current alternative.
Help	Opens the online help.