Surface Water Modelling

Surface water modelling is generally required for:

  • predictive accident modelling under COMAH, or occasionally Environmental Permit
  • obtaining a Consent to Discharge for direct effluent release into surface waters, although this is no longer common from industrial sites
  • investigations following an accidental release of polluting materials.

We can help with several types of surface water modelling, including to rivers, estuaries and the sea.

For river pollution modelling, we use an in-house model which is based on the equations within the H1 model from the Environment Agency.  This has been developed because, although there are several river dispersion models available commercially, none of them have been approved by the Environment Agency at the time of writing.

The in-house river model equations are more flexible than those used in H1, as they can be used for scenarios where:

  • there is an existing background level of a pollutant in the river upstream of the release point
  • there are several sequential releases of the same pollutant from site
  • there are dilution effects downstream as tributaries join the river, or it joins larger rivers
  • the pollution is released into the river via groundwater (we have another connecting in-house model which takes the pollution in groundwater and estimates its overall release to river via the hyporheic zone).

For other aquatic environments, the Environment Agency have approved a variety of free and commercial estuary and marine models, and we are happy to use them where appropriate.  We have also developed in-house models for estimating pollutant migration through narrow “bottle shaped” estuaries, and from this estuary type into the sea.

If specific complex modelling is required for surface water releases, we may use specialist sub-contractor modellers.

If you need help with Surface Water Modelling and Risk Assessment, contact Janet on 01422 24 22 22 or email email Janet.