The author describes the setting up of ten regional water authorities in England and Wales with the duty of managing water, from the supply of drinking water to the treatment of sewage and the control of rivers. The new Control of Pollution Act 1974 is examined, particularly with regard to the powers it contains for the water authorities to take action if oil pollution occurs. This includes both action to stop discharges containing oil and also to remove oil once it has entered a river. The author discusses the results of a survey to assess what are the main causes of oil pollution and suggests means of reducing these. Finally, there is a description of a number of particularly significant cases of oil pollution and the steps taken to prevent recurrences.