period 2005–13 Thames Water was the most heavily fined water company in the UK for pollution incidents, paying £842,500 for 87 events. In 2016, it paid the largest fine for a single pollution incident of £1 million. In March 2017, Thames Water was fined a record £20.3 million after it pumped nearly 1.5 billion litres of untreated sewage into the River Thames. The company also admitted other water pollution and offences in Buckinghamshire and Oxfordshire. In awarding the fine, Judge Francis Sheridan noted the company's "continual failure to report incidents" and "history of non-compliance", saying: "This is a shocking and disgraceful state of affairs. It should not be cheaper to offend than to take appropriate precautions. I have to make the fine sufficiently large that [Thames Water] get the message", adding that, "One has to get the message across to the shareholders that the environment is to be treasured and protected, and not poisoned.". What was "shocking and disgraceful" was not just the scale of the pollution, but that it was intentional. Sheridan added "the constant use of flow clipping to protect the treatment process, so that, despite the regular and prolonged discharge of untreated sewage to the River Thames via the storm outfalls, all samples taken at the final effluent outfall complied with the permit. This was deliberately done and gave a false impression of the sewage treatment works’ performance and undermined the operator's self-monitoring process." Conversely, in 2014, Thames Water admitted that it had accidentally over-reported the number of properties at high risk of sewage flooding between 2005 and 2010. It agreed to a compensation package for customers of £86 million. In 2022, a report published by the parliamentary Environmental Audit Select Committee on water quality in the UK's rivers showed that Thames Water's Mogden wastewater treatment works in Isleworth discharged a quantity of sewage which would fill 400 Olympic-sized swimming pools on 3 and 4 October 2020. Other incidents In September 2007, of the River Wandle, Greater London was polluted. In January 2009, Thames Water pleaded guilty at Sutton Magistrates Court, and was subsequently fined £125,000 at Croydon Crown Court and ordered to pay £21,335 in clean-up and investigation costs. In February 2010, on appeal, the fine was found to be "manifestly excessive" and was reduced to £50,000. On 5–8 June 2011, more than , or 230,000 tonnes, of sewage were released from Mogden Sewage Treatment works,