Effectiveness of information techniques application for assessment of the water bodies’ xenobiotic pollution has been demonstrated. With the help of international and national databases, as well as calculative methods of the biological activity forecasting the degree of danger of the found organic compounds has been found. The list comprises toxicity of petroleum water pollution; organic xenobiotics found in the Moscow drinking water supply sources; substances that pollute the Baltic Sea; and chlorine/organic compounds produced in the process of waste water disinfection. Effectiveness if the information techniques application including search of data on a compound in international and national databases, forecast of biological activity and quantitative indicators with specialized software for assessment of water quality has been proved. A toxicity forecast has been carried out for organic compounds found in the sources of Moscow drinking water supply. This forecast enables to range these compounds in terms of their adversity degree, as well as predict possible by-effects for human beings and some species of hydrocoles. It has been shown that information techniques of the biological activity forecast can be used for defining of novel qualitative and quantitative data on this activity forms and the toxic effects’ concentration thresholds.