Using the critical research framework of immanent critique, this thesis assesses judicial interpretations of the general water pollution offences under Regulation 12(1)(b) of the Environmental Permitting (England and Wales) Regulations 2016. Regulation 12(1)(b) states that âa person must not, except under and to the extent authorised by an environmental permit cause or knowingly permit a water discharge activity or groundwater activityâ. Immanent critique has the aim of investigating and assessing the relationship between ideals and reality to measure how far the key claims, values or assumptions of a legislative provision or institution are realised in actual practice. The thesis uses the term âinternal coherenceâ to describe coherence between the legislative goals that underpin the water pollution offences of âcausingâ and âknowingly permittingâ and judicial interpretations of these offences. A critical analysis of judicial interpretations of the water pollution offences of âcausingâ and âknowingly permittingâ using the lens of immanent critique complements and develops the existing water pollution prevention and environmental law literature. It illustrates the merits of assessing the relationship between âlaw in booksâ and âlaw in actionâ by examining the mismatch between legislative ideals and interpretative outcomes. An analysis of the relationship between the promise and performance of the general water pollution offence of âcausingâ (and to a much lesser extent the offence of âknowingly permitsâ due to the paucity of prosecutions) has shown that in the early 1970s, the House of Lords (now Supreme Court) supported an internally coherent interpretation of âcausingâ. During the 1990s, judicial interpretations of these water pollution prevention offence were not internally coherent. Recently, the courts have explicitly supported an internally coherent interpretation of the water pollution offence of âcausingâ. This thesis is based on the argument that there is little or no point in introducing numerous environmental protection laws if efforts are not then made to investigate how these laws operate and if their professed ideal(s) are being realised in actual practice. This thesis illustrates the practical application of the theoretical framework of immanent critique to help legal academics promote coherence within the legal system, add to discussions about the maturity of environmental scholarship, and subject judicial reasoning to critical examinations in order to encourage public confidence in legal personal and address concerns and issues that (environmental) judges may either typically share or are likely to face during the interpretative process.