Flying In the Face of the Evidence?

Riverflies and their aquatic larvae, are essential components of food chains for freshwater species of fish and other animals found in/by lakes and rivers. One might suspect a group of 'citizen scientists' working for 'Save Lake Windermere and Wild Fish', to have vested interests. Their current observations, however, certainly seem worthy of detailed consideration (https://www.theguardian.com/environment/2024/jan/23/invertebrates-decline-stream-cunsey-beck-lake-windermere). This 'citizen scientist' group, monitored the abundance of riverfly species (Mayflies; Caddis flies; Stoneflies etc.) larvae, in a beck (stream) feeding Lake Windermere. Lake Windermere is the largest lake in Cumbria's Lake District National Park (Northwest England). By repeated dipping, the 'citizen scientists' found a massive (76%) decline in riverfly larval populations. They also noted (surpise, surprise) that a privatised English Water Company, United Utilities, had a wastewater treatment works near the monitored beck. The UK's Environment Agency (EA) issues a permit for United Utilities discharge to raw sewage, into that beck, at the time of flooding risk. 'Save Lake Windermere and Wild Fish' suspect that raw sewage discharge, accounted for their observed decline in insect life. They questioned, whether the EA permit provides adequate environmental protections for the lake and its residents, in what's Site of Special Scientific Interest. This is currently refuted by the EA. However, the privatised English Water Companies, including United Utilities, have long track records for illegally discharging untreated materials into lakes and coastal waters. Circumstantial evidence, at least, seems to be stacking up!