What is the best way to model a contamination below groundwater level?

S-Risk allows to define soil layers down to the groundwater table, but not lower. For situations with a contamination beneath groundwater level, S-Risk calculates transfer based on the groundwater concentration (affecting volatilization, permeation and exposure pathways with direct use of groundwater).

At this stage, it is uncertain wether we will implement the models needed for such "submerged" soil layers in S-Risk.

However, there is a workaround for situations like these:

  • convert the measured concentration of the submerged soil layer to an equivalent pore water concentration. This can be done:
    • based on equations 17/18/19 of the Flemish/Brussels and Walloon version of the Technical Guidance Document, or
    • based on the approximate formula Cporewater [mg/m³] = Csoil [mg/kg] × 1000 / Kd [l/kg].
      The calculation of the Kd depends on the type of chemical. More information is given in the Technical Guidance Document - chapter 2.2.1: Kd values.
  • enter the calculated pore water concentration in S-Risk as a measured groundwater concentration (using the "Water" and "Concentrations" tabs)

If you have an actual concentration measurement for groundwater, use that value for the measured groundwater concentration.

last modified on 10/04/2017 - 12:26

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