Simplify Source Model Set-Up with the New CSV Import Feature

One exciting addition in the latest release of TS-CHEM (version 2024-3) is the new “CSV Import” feature for time-varying source concentrations. Several of the TS-CHEM solutions allow the user to specify source concentrations that change with time (ATRANS3 and ATRANS4; AT123D-AT FT and AT123D-FT). The gradually varying concentration being released from the actual source (smooth red curve in the chart below), is represented in the TS-CHEM analytical model as a series of concentration steps (blue step changes in the chart below).

The CSV Import feature can be used to efficiently set up and solve a time-varying source model by allowing users to import time-and-concentration source histories that have been created manually by the user, or exported from other user software, in CSV format. For example, the SILT soil source leaching model is capable of calculating and exporting a CSV file of groundwater source concentrations from a soil zone contaminant source (see the SILT Blog Post for more information).  

User-created source history files can be used to analyze various scenarios for releases from an industrial facility over time. Concentration versus time output from software that calculates source release concentrations - - for example, SILT leaching a contaminant from soil to groundwater or SourceDK representing dissolution and dissipation of a NAPL source - -  can be saved as a CSV file and imported directly into TS-CHEM.

Using the new CSV Import feature is simple. In the Model Data tab, for transient (stepped through time) concentration data sets, begin by clicking in the data entry field, and a data entry pane is opened on the right side of the window to facilitate data entry (see Figure 1).

Figure 1. Source Concentration Data Entry Pane

To import a time-and-concentration source history file (in CSV format), click on the Import button to open the CSV data import control panel (see Figure 2).

Figure 2. Import CSV Data List Window

Click on the Choose button and navigate to the CSV data file. The file contents will be displayed in the Preview window. Use the “Significant Digits” setting to format the concentration values to improve viewability (excessively long concentration values with many digits to the right or left of the decimal point can be difficult to read). If the file was created with a header row, the check box can be used to eliminate that row before import.

Checking the “Replace” check box will completely replace (overwrite) all data pairs currently in the source history list. Unchecking the “Replace” check box will merge the CSV file data pairs into the current source history list, and will sort the list to properly organize the specified history of concentrations. Note: If there is a time-and-concentration data pair in the CSV file with a time identical (within 1E-04) to a time already in the source history list, the CSV file data pair will overwrite the current list data pair; thereby effectively specifying an updated concentration for that time.

Click the Import button and the CSV file data will be added to the source history list (see Figure 3).

Figure 3. Source Concentration Data Entry Pane (with imported data)

In addition to the new CSV Import feature, several other updates and improvements have been incorporated into TS-CHEM version 2024-3, including:

• Plume Center of Mass analysis tool for MNA and other analyses
• Data entry enhancements
• Other minor improvements and bug fixes

To take advantage of these updates and improvements and test out the new CSV Import feature, head over to the TS-CHEM Website to download version 2024-3 today!