S-Risk 1.0.10

13/03/2014

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".