Ofwat has proposed significant fines totaling £168 million against Thames Water, Yorkshire Water, and Northumbrian Water due to failures in wastewater management, following its largest investigation to date into the industry. Thames Water faces a £104 million penalty, Yorkshire Water £47 million, and Northumbrian Water £17 million, reflecting 9%, 7%, and 5% of their respective annual revenues. The investigation revealed that these companies routinely discharged untreated wastewater into rivers, violating guidelines that permit such actions only under exceptional circumstances. Ofwat's Chief Executive, David Black, emphasized the severity of the failures, which included inadequate maintenance and slow upgrades to their systems, resulting in environmental harm. The proposed fines are now subject to consultation, with a broader investigation ongoing that may affect additional water companies. Public outrage over these issues has prompted government promises for industry reform to ensure cleaner waterways.