Matt Staniek from the Save Windermere campaign says treated sewage at places like Langdale Wastewater Treatment Plant is part of the problem. Permission has been granted to discharge more than one million liters of treated wastewater per day into the River Brathay, which flows into Lake Windermere. There are other similar outflows around the catchment area, and although some of the phosphorus may be removed at wastewater treatment plants, some may also end up in rivers.