Harmful bacteria 'highest in summer' in Windermere
Published: 8/19/2025

Harmful levels of E.coli and IE bacteria have been found in Windermere, England's largest lake, during the summer months, potentially indicating sewage pollution. A citizen science project called the Big Windermere Survey revealed concerning levels of illness-causing bacteria at popular swimming and watersports spots. Campaigners are urging authorities to take decisive action to address the water quality issues in Windermere, a cherished site in the Lake District attracting millions of visitors annually. Defra has committed to improving water quality standards to protect the lake's ecosystem and rare species like Arctic char.