The Principles that have been collected in the following pages outline some of the problems raised by the codification and progressive development of international law on water pollution. These principles have been formulated with reference to international agreements mostly concluded since the adoption of the Helsinki Rules (1966) and having regard to the vast documentation recently produced on the subject by various international bodies.
It is not difficult to select a limited number of principles as the most representative of the topic. The real problem is how to interpret them in terms of international legal rights and duties, because, either we rely on positive treaty law, and then are faced with the doubt that the provisions under inspection evidence the lack — not the existence — of a corresponding general principle; or we move from an abstract notion of water pollution that can only be defined by damage and whose legal implications cannot be appreciated except with reference to international responsibility, circumstances, and equity.