We were contracted by Helius Energy PLC to assess the impact of the effluent plume from a proposed biomass station within Southampton Water. The results from this study contributed to the Environment Statement, which was submitted to the National Infrastructure Planning Inspectorate.

Using a numerical model, we evaluated the dispersion of the cooling waters extracted and subsequently returned to the estuary at an elevated temperature and salinity, containing low concentrations of a number of treatment chemicals, including biocides and corrosion inhibitors.

Our numerical model provided excellent representation of water levels, current speeds and directions, and with the rotational characteristics of the tide and the particular features of the Solent tidal curve resolved by the model.

The model provided a conservative assessment of plume dispersion in the study area in comparison to independent studies, thereby representing the effects of the possible worst case within Southampton Water.