To ask His Majesty's Government what assessment they have made of the environmental impact of pollution in Lake Windermere.

A thorough investigation by the Environment Agency (EA) into the pollution incident at Lake Windermere earlier this year remains ongoing, which involves examining further evidence from United Utilities (UU). If the EA determines a permit breach has taken place, it will not hesitate to take enforcement action up to and including a criminal prosecution.

Windermere is affected by pollution from a range of different sources, including sewage discharges from water company assets, private septic tanks/sewage works and road and agricultural run-off, as well as physical modifications. Climate change has also altered temperature, precipitation and weather patterns which can affect the lake's water quality, by altering nutrient cycles, water chemistry and aquatic habitats, and affect the amount of water resulting in droughts and floods.

The last Water Framework Directive full water body classification results in 2019 assessed that Lake Windermere achieved moderate ecologic status and is impacted by excessive nutrients, leading to algal growth and cyanobacterial blooms.

Recent data shows a 30% reduction in phosphorus – which can lead to algal blooms – entering the lake since 2020 and this reduction is predominantly due to EA-driven improvements to UU Wastewater Treatment Works.

Water quality modelling continues to quantify the different sources of pollution in Windermere and the impact that it is having in different parts of the lake. The EA is also working with the Love Windermere partnership to improve the overall health of the lake through behavioural and societal change.