https://www.gov.uk/government/news/thames-waters-250000-fine-is-upheld-by-the-court-of-appeal

Environment Agency: The sentencing decision took into account the profit made by the company to ensure the fine is proportionate.  Thames Water had allowed untreated sewage to enter a 143 acre nature reserve owned by the National Trust within an area of Outstanding Natural Beauty and a site of important nature conservation, popular with walkers, schools and naturalists. Despite repeated alarms in Thames Water’s control centre showing a total pump failure at a sewage pumping station it was 5 days until the company attended the site. The pollution was brought to the attention of the Environment Agency and Thames Water by a member of the public. For 5 days raw sewage flowed into the reserve polluting a rare alder carr woodland and a specially developed newt pond, killing invertebrates in watercourses for up to 600 metres, and closing the reserve to visitors.