Water quality refers to the physical, chemical and biological content of the water column. In the UK there are a number of European designations that are designed to protect water quality (e.g. the Water Framework Directive, the Bathing Water Directive and the Shellfish Water Directive) and Tidal Lagoon Power (TLP) has a responsibility to ensure that the likely impacts of any project are assessed against these.
The construction, operation and decommissioning of a tidal lagoon has the potential to affect water quality through a number of different pathways, including: changes in salinity and temperature, changes in sediment movement and concentration (resulting in alterations to oxygen uptake or distribution of contaminants) and changes to the flows and water levels (affecting concentration of pollutants).
In order to assess the likelihood of these potential changes, TLP are able to make use of a number of datasets already currently available. In order to support this information with more localised and detailed data, we are able to commission additional marine water quality surveys where required. Surveys allow the collection of water samples at set locations which can be analysed for salinity, temperature, dissolved chemicals, suspended solids and bacterial concentrations. If necessary, sediment plume modelling can also be undertaken to identify and predict the impacts of an increase in suspended sediment in the water column.