Release Notes

S-Risk 1.1.0

Released on April 14th, 2015.
List of changes in this release
S-Risk 1.1.0 is a major release introducing two new features: the summary report and simulating over concentration ranges. We also extended the S-Risk calculation capacity and adjusted a number of minor issues.

These are newly introduced features and, while tested as thoroughly as possible, they may still show problems in some situations. If you notice any problems, or if you suspect any errors or malfunctioning, please let us know via the S-Risk Helpdesk at

Summary report
S-Risk now provides a "summary report", an overview of the main S-Risk results on the Results tab. This report shows the latest calculation results in a more efficient and attractive way, while still aiming to be as complete as possible.
The summary report will also be generated for your existing simulations. The existing, extended S-Risk PDF reports are still available, and complement this summary report with a lot more detailed configuration details and intermediate results. Whenever the summary report does not provide the level of detail needed, the extended report can be used.
The summary report contains the following sections:
  • "Main results"
    This table shows, per chemical, the most critical risk results and concentration indices (application II) or the most stringent soil concentrations (applications I and III) for the different risk endpoints. Values exceeding the risk thresholds are shown in red for quick inspection.
  • "Conceptual site model"
    This section summarizes the model configuration you have made, showing the main determining parameters and concentrations in your simulation.
  • "Results per chemical"
    This section shows the detailed results per chemical substance in your simulation and resembles the "Summary" section in the extended PDF report. This concerns the risk (or critical soil concentration) results, concentration indexes, the detailed exposure results per pathway and local versus background exposure.
  • "Listing of user-modified parameters"
    This last section gives an overview of all parameters that were changed from the default value by the user in this simulation. Comments, if provided by the user, are shown.

Clicking the "Print" button enables you to get a clean printout of the summary report. Via "print to PDF" functionality, you can save the report to hard disk (the Chrome browser allows saving to PDF directly, for other browsers there are solutions like PDFCreator, Adobe Acrobat, ...).

Simulating ranges of soil/groundwater concentrations

The second new feature can be found in the new "Graph" tab, next to the "Results" tab.

Here, you can simulate a range of concentrations for a selected chemical, soil layer/groundwater layer and result parameter. S-Risk will vary the concentration of this chemical in the specified soil layer between the specified lower and upper limits, and calculate the corresponding values for the result parameter (risk or concentration index).
When the calculations have been executed, a graph will be constructed showing the value of the result parameter over the specified concentration range.

This functionality serves various purposes:

  • it allows you to quickly get an overview of how the risk evolves in function of the concentration, without manually changing concentrations all the time
  • it allows you to get a quick estimate of the remediation goal, by visualizing the point where, for example, the risk index exceeds the RI = 1 level
  • it allows you to get more context for the results in Application I and III. Especially when application I or III results in strange remediation goals (e.g., negative values or warning messages in the extended report), this feature can show you why.

Extended calculation capacity

Until now, S-Risk relied on two calculation servers to perform the requested S-Risk simulations. Calculation scheduling was based on a FIFO (first-in, first-out) principle. On occasion, this resulted in simulations being "queued" for some time before calculations could start.

We have now added a third calculation server and a per-user "simultaneous simulation" limits to reduce the chance of temporary calculation bottlenecks.

Additional adjustments

  • resolved issues with periods versus commas in entered values in the Dutch interface
  • adjusted saving of measured egg concentrations 
  • resolved issues with K_p value display in Exposure tab
  • land use parameter comments now shown in the extended report



Released on January 21st, 2015.
List of changes in this release
S-Risk is a minor release correcting minor issues introduced with release 1.0.12.
  • interface language can be switched to Dutch again
  • adjusted the display of soil concentration values

These issues have not impacted the S-Risk calculations or results in any way, the above fixes are only cosmetic.

S-Risk 1.0.12

Released on January 19th, 2015.
List of changes in this release
S-Risk 1.0.12 is a smaller release with minor fixes and adjustments, preparing for feature additions in upcoming updates.
  • application I now only shows appropriate landuse choices
  • fixed situation where report wouldn't get generated correctly sometimes
  • improved copy operation simulations
  • Indoor tab now also provides access to the buffer space parameter
  • corrected Lead BTF value for sheep meat, also adjusted substance data sheet accordingly
  • improved handling of database connection errors in model core
  • update of several graphical user interface libraries

S-Risk 1.0.11

Released on September 8th, 2014.

List of changes in this release

S-Risk 1.0.11 is a smaller release that fixes a few specific issues:

  • configuration changes to fix the "blank pages" problem that sometimes occurs on S-Risk login;
  • adjustments for minor report issues;
  • groundwater concentration is now also reported in Conceptual Site model report section;
  • adjusted the account expiration email to be more informative and describe the correct procedure.

S-Risk 1.0.10

Released on March 19th, 2014.

List of changes in this release

S-Risk 1.0.10 introduces a number of changes parameter values influencing the prediction of concentrations in indoor air following volatilization from soil or groundwater. These changes allow S-Risk to better cope with known overestimations by the Volasoil model for certain compounds.
These changes are introduced after discussion with and in close cooperation with OVAM and parties directly affected by the volatilization model issues.

It is important for the user to be aware of these changes, as they can have an impact on future results and simulations.

→ Changes in parameter values for volatilization to indoor air

The bufferspace is the minimum distance between contamination and building floor that is considered when calculating volatilization of a compound from soil/groundwater to the indoor environment. This parameter is not accessible in the S-Risk interface, but is used in the calculations (see the Technical Guidance Document on volatilization to indoor air).

  • in Application I, the value of the bufferspace is left unchanged at 0.75m
  • in Applications II and III, the value of the bufferspace is increased from 0.05m to 0.10m

For existing simulations, nothing changes and the old bufferspace of 0.05m is kept.
This value is only adjusted to 0.10m for (i) newly created simulations and (ii) whenever the application type (I, II or III) of an existing simulation is changed.

Next to the bufferspace, we have changed the default basement/crawlspace wall quality from average to good, by changing the following parameter values for new simulations:

  • kv,w = air permeability of the basement/crawlspace wall: value changes from 1×10-11 to 1×10-13
  • εv,w = air-filled porosity of the basement/crawlspace wall: value changes from 0.12 to 0.07

These new parameter values will only be applied for newly created simulations. In existing simulations, everything remains unchanged unless the user him/herself adjusts the values. 

The new values will lead to a reduction in predicted concentrations in indoor air due to vapour intrusion.

→ Changes in parameter values for the capillary zone

Values for the water-filled porosity of the capillary zone (parameter θw,cz) have been updated to more accurate values.

Soil type Old S-Risk value New 1.0.10 value
Generic 0.24 0.34
Loam 0.27 0.35
Clay 0.30 0.38
Sandy loam 0.25 0.34
Light sandy loam 0.23 0.33
Loamy sand 0.22 0.32
Heavy clay 0.37 0.43
Sand 0.22 0.33

These new parameter values will only be applied for newly created simulations. In existing simulations, everything remains unchanged unless the user him/herself adjusts the values. The new values will lead to a reduction in predicted concentrations in indoor air due to vapour intrusion from contaminated groundwater.

→ Other changes

Aside from these parameter changes, S-Risk 1.0.10 also improves on flux calculations for volatilization to indoor air, and fixes some smaller interface bugs and report issues.

  • Volatilization to indoor air calculations would ignore the contribution of deeper layers in certain situations - this is improved now
  • The list of simulations would not load when some basement parameters were missing - this is fixed now
  • Groundwater concentration configuration in Water tab and optimization setting in Concentrations tab could get inconsistent - this is fixed now
  • The report now also reports S-Risk version numbers in the footer of each page. Two version numbers are reported:
    • the S-Risk version in which the simulation was created, or of the last application switch
    • the S-Risk version with which the reported results were calculated

The "creation" version number (or version number of the last application switch) is relevant to know the default parameter values used, and is linked to, for instance, the value of the buffer space used. The "calculation" version is relevant for changes in the modelling code, like those reported here under "Other changes".

S-Risk 1.0.9

Released on February 24th, 2014.

List of changes in this release

S-Risk 1.0.9 is a maintenance release with a number of smaller improvements, and a few adjustments to better cope with the higher server loads we've been experiencing since January. In following updates, we will continue to work on reducing the server load and speeding up simulations.

  • we now eliminated the situation where, in situations of high server load, S-Risk would show the "Calculations completed" message too early, while calculations were actually still running in the background
  • loading/saving model configurations from/to the database by the calculation servers is much faster now
  • storage of plant characteristics is more consistent now
  • a number of small report issues were fixed and applied
  • changes to prevent accounts from being unable to log out correctly


S-Risk 1.0.8

Released on October 22nd, 2013.

List of changes in this release

S-Risk 1.0.8 is a bugfix release, adjusting the loading of chemicals in the S-Risk calculation model. This was a potential source of errors when additional chemicals were added after a first calculation.

Licensees with simulations potentially affected by this problem have been informed earlier. It is sufficient to re-run the calculations for the affected simulations to generate a new report with correct results.

S-Risk 1.0.7

Released on October 21st, 2013.

List of changes in this release

  • Risk tab:
    • S-Risk required valid risk threshold values for ALL routes of an enabled local effect type, which are not always available. This is now more flexible: for local effects, S-Risk now allows risk threshold for individual routes to be left empty.
    • edit fields in the Risk tab are now more clearly indicated to avoid confusion
  • Simulation names are not allowed to have special characters anymore, as this causes problems for downloading report files.
  • Bugfix in calculations when drinking water supply pipe material = "Other"
  • Benzo(g,h,i)perylene data for background exposure via food have been adjusted.

Background & implications of these changes

These are mostly interface-related changes, not affecting simulation results in any way.

Only the changes for benzo(g,h,i)perylene need special attention. This concerns changes in the values for background exposure via food. These values changed from NO background exposure (0 mg/ for all age categories) to following values listed hereafter. The impact is minimal as background exposure is negligible compared to the oral TDI of 3E-2 mg/kg.d:

Age category

Old value

New value


1-3j 3.44 · 10-6
3-6j 0 3.70 · 10-6
6-10j 0 3.12 · 10-6
10-15j 0 2.42 · 10-6
15-21j 0 2.12 · 10-6
21-31j 0 1.98 · 10-6
31-41j 0 2.00 · 10-6
41-51j 0 2.00 · 10-6
51-61j 0 1.98 · 10-6
>61j 0 1.98 · 10-6