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 m²
  • 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 updated to 1.0.10


S-Risk has been updated to version 1.0.10. Please pay attention to the release notes for this release, since it applies changes in parameter values for certain parameters important to volatilization to indoor air.

For an overview of the changes in this release, see our Release Notes page.

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 offline coming Thursday


Coming Thursday, S-Risk will be unavailable in the morning for an update to our network configuration. Some downtime can be expected from 8am on.

Server offline for updates


Later today, the S-Risk server will be offline for a short while to apply necessary operating system updates. Some downtime can be expected at 5pm.

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.