FOCUS_TOXSWA_1.1.1 Note

Known bugs in released version of FOCUS_TOXSWA_1.1.1:

1. Crashed run for compounds with Koc values between 10000 and 30000 L/kg

Runs for compounds with Koc values ranging from 10 000 to 30 000 L/kg may crash with the following error message in the runid.err output file:

"A fatal error occurred in subroutine wbso at time: dd-mmm-yyyy-hh:mm
Positivity condition 5 (brdd >= 0) not fulfilled
At node: 1 brdd is - [negative value]
Take smaller time step deltwb for sediment layer "

Selecting a smaller time step deltwb for the sediment layer will NOT solve the problem, as is suggested in the message above. The user should perform the TOXSWA run with the standard segmentation for the sediment layer, and NOT with the finer segmentation, that is automatically selected by the TOXSWA-GUI for compounds with Koc values from 10000 L/kg onwards at present. The standard segmentation consists of 14 segments, ranging from 1 mm in the upper part to 3 cm in the lowest part of the 10 cm thick sediment layer. The finer segmentation consists of 27 segments, ranging from 0.03 mm in the upper part to 3 cm in the lowest part of the 10 cm thick sediment layer. This finer segmentation is necessary to obtain a convergent numerical solution for compounds with a high Koc. So, to bypass the crashes, the user should use the standard sediment segmentation. This can be done within the TOXSWA-GUI by:

  1. Enter the TOXSWA shell.
  2. On the "TOXSWA - Projects" screen select the project, containing the crashed runs and copy it.
  3. Select this copied project and open it
  4. On the next screen "TOXSWA project:.." delete all runs that run fine, so keep only the crashed runs.
  5. Press the button "Calculation". As the runs now are non-FOCUS runs the standard segmentation for the sediment is being selected, which is what is needed, so just press OK on the popped up warning and run TOXSWA. Please notice that this warning pops up before each run, so you need to click OK before each run (i.e. you cannot run the entire project unattended as in normal FOCUS mode).
  6. Report the obtained results, indicating that the standard sediment segmentation was used instead of the finer segmentation.

2. TOXSWA project with multiple runs cannot be run unattended (Koc values of 10000 L/kg and higher)

For projects for a compound with Koc values of 10000 L/kg and higher a finer segmentation of the sediment layer is automatically taken by the TOXSWA-GUI in order to obtain a converging numerical solution of the Convection-Diffusion Equation in the sediment. However, before each run a response box pops up warning the user that he is using this smaller segmentation and this box has to be clicked away. This implies that projects for compounds with Koc values of 10000 L/kg and higher cannot run unattended, as in the normal mode.

3. Too laborious solution given in Known bugs of TOXSWA read-me file:

In case of unwished commas as decimal symbols in MACROs m2t files it is NOT necessary to de-install and re-install (after changing the national settings) the entire SWASH software package as suggested, but it is sufficient to change the national settings (into a default national settings using dots as decimal symbol) and to restart the computer. Next, new m2t files need to be created, with dots instead of commas as decimal symbols.

4. Maximal dosage entered in non-FOCUS runs

In non-FOCUS application schemes the maximal dosage that can be entered is 1000 kg/ha. The GUI gives only warnings for dosages above 1 000 000 kg/ha, but runs with dosages above 1 000 kg/ha will stop because the TOXSWA model does not accept these dosages.