The study course presents an in-depth study of the chemical, biochemical and toxicological processes that take place in contaminated waters. The study course presents the main groups of water pollutants and protection possibilities against pollution: major organic pollutants (including petroleum products) of the hydrosphere, inorganic and toxic pollutants. As part of the study course, students will be introduced to the methods of analysis of polluted waters, methods validation principles, uncertainty calculations, methods of expressing pollution, laboratory techniques and working principles in the laboratory accredited in the accordance with the requirements of LVS ISO 17025. The study course will present the most important integral pollution values for water pollution characterization: chemical oxygen demand, biochemical oxygen demand, petroleum products, suspended substances and nutrients. In the study course, different possibilities for recovery and re-use of different grade polluted waters are examined and assessed.