Investigations by Ofwat have concluded that between 2010 and 2017 Southern Water failed to operate a number of wastewater treatment works properly, including by not making the necessary investment, which led to equipment failures and spills of wastewater into the environment.
Waste water discharge can contain a toxic cocktail of domestic, industrial and agricultural pollution including hydrocarbons, heavy metals and chemicals like pesticides as well as the nutrients from sewage systems. These pollutants contribute significantly to declines in freshwater and marine species such as salmon and native crayfish and can have knock on impacts on humans through the shellfish that we eat, for example.