Using Trade and Waste Water Events

To use Trade and Waste Water Events during a simulation, the following steps are required:

• link the profiles in the Trade or Waste Water event to subcatchments in the network
• include the Trade or Waste Water Event as part of the simulation when scheduling a run

Linking profiles to subcatchments

Waste Water profiles can be:

• linked directly to subcatchments
• included as part of a Land Use Definition and used as a default for all subcatchments using this Land Use

It is not possible to set a default Trade Waste profile in the Land Use. Trade Waste profiles tend to be specific to individual sites, such as factories, and not associated with a particular type of land use, therefore trade waste profiles are set in the subcatchment.

In the Land Use

There are three parameters that need to be set for each Land Use if the default values for subcatchments are to be used:

• Wastewater Profile - the profile number from the Domestic Wastewater Event
• Population Density and Connectivity - these parameters are used when calculating the actual flow from Per Capita Flow defined in the wastewater profile

In the Subcatchment

To override defaults from the Land Use, or if defaults have not been set, the following values need to be defined for domestic wastewater:

• Wastewater Profile - the profile number from your Domestic Wastewater Event
• Population and Connectivity - used when calculating the actual flow from Per Capita Flow
• An Additional Foul Flow can also be set that will be added to the flow calculated from the wastewater event

The calculated flow is a nominal flow that is then multiplied by the time varying multipliers set up in the wastewater profile to create actual time varying flows.

For trade events the following values must be defined:

• Trade Profile - the profile number from the Trade Waste Event
• Trade Flow - the nominal flow that is then multiplied by the time varying multipliers set up in the trade profile to create actual time varying flows

Setting up the simulation

To set up Domestic Wastewater or Trade Waste Events in the simulation the event(s) must be included in the appropriate boxes on the Schedule Hydraulic Run View.

Note:

A run containing a waste water or trade waste event will take account of any local time changes when calculating the waste water or trade waste profile.

The events contain profiles that are used as dimensionless multipliers for the nominal flows to produce a time varying flow. The events contain two types of time varying profile:

Calibration profiles	By default, Calibration profiles are used when carrying out a simulation with observed data. Different flow profiles can be set up for different days of the week, and an additional profile can be set up for monthly variation. See Editing Trade and Waste Water Events. See below for details about how InfoWorks ICM decides which profile to use.
Design profile	By default, the design profile is used when carrying out a simulation with design events. Design events do not have a real start date and time. Instead, they use Relative Date and Time. See below for details about how InfoWorks ICM decides which profile to use.

InfoWorks ICM will use the Calibration Profiles if any of the following is true:

• Any of the event data in the simulation (anything listed in the Event Inputs box on the Schedule Hydraulic Run View) uses Absolute Date and Time.
• An Absolute Date and Time is specified in the Run Parameters box on the Schedule Hydraulic Run Dialog.

If none of the above is true InfoWorks ICM will use the Design Profile.

It follows that a simulation that uses design events can be forced to use Calibration Profiles by changing the start time in the Run Parameters box.

However, a simulation with observed data cannot be forced to use the Design Profile. To simulate the design profile it is necessary to set both weekday and weekend profiles to the same values as the design profile, and set all the monthly multipliers to 1.00

Calculations during the simulation

The actual inflows to the subcatchment from domestic wastewater and trade waste during the simulation are calculated as follows.

For domestic wastewater:

1. The nominal flow is calculated
   • If Population is not set in the subcatchment then a value for Population is calculated from Population Density (Land Use) multiplied by Contributing Area (subcatchment)
   • Nominal flow is then Population multiplied by Connectivity multiplied by Per Capita Flow (wastewater profile) plus Additional Foul Flow
2. The nominal flow is then multiplied by the appropriate multiplier to give the actual flow for the current timestep. The multiplier will depend on the type of profile being used:
   • Design profile value

Calibration Weekday (Monday to Friday) or Calibration Weekend (Saturday and Sunday) value multiplied by the Monthly value. If specific day of the week calibration profiles are defined, the day of the week profiles will override the Weekday and Weekend profiles.

For trade waste:

1. The nominal flow is calculated by multiplying Trade Flow (subcatchment) by the Flow Scaling Factor (trade waste profile). (Flow Scaling Factor exists for compatibility with previous versions. This value should always be set to 1.0)
2. Nominal flow is then multiplied by the appropriate multiplier as described above.