Sources of environmental law in a broad sense are generally binding of conduct in environmental legal relations, expressed in a special form. To become universally binding, these rules must be presented in a certain, official form, fixed by the state. For each legal system of modern states, their sources of law are characteristic. Judicial precedents are the basis of the legal system of the Anglo-Saxon legal family, and therefore they are recognized as the main sources of environmental law in countries such as England, the United States and Canada.