The Environment Agency's report found that whilst there were improvements in 2020, no single company achieved all its expectations for the period 2015 to 2020. These included the reduction of total pollution incidents by at least one-third compared with 2012 and for incident self-reporting to be at least 75 per cent.

The report also found that the sector coped well with Covid-19 pressures in 2020 and recently committed over £850m to help contribute to a green recovery from the pandemic. It added that a number of companies are still failing to live up to their responsibilities to regulators, their customers and the environment.

Southern Water and South West Water were rated as the companies least likely to meet environmental expectations, followed by Anglian Water and Thames Water.

The five other water firms (Northumbrian Water; Severn Trent Water; United Utilities; Wessex Water, and Yorkshire Water) were rated more highly, although certain improvements...