New comprehensive data on the geochemistry of trace organic contaminants in groundwaters and river water of Tom' and Upper Ob' rivers drainage basins are systematized in this paper. A total of 61 samples of natural waters at different levels of pollution were collected and analyzed by chromatography/mass spectrometry. Analyzed trace contaminants included dissolved hydrocarbons, phenols, dialkyl phthalates, carboxylic acids, ethyl esters, organic phosphates, propyl esters, chlorohydrocarbons, higher alcohols, etc. It was established that the distribution of organic trace contaminants in waters is controlled mainly by their sources and the level of pollution of natural waters by organic compounds of the anthropogenic origin. Trace contaminants derived from anthropogenic sources are present mainly in the rivers and upper aquifers. Their content in groundwaters decreases with increasing depth, though there are some exceptions. Trace organic contaminants of natural origin show different behavior. They are present at increased concentrations in waters that contain natural organic matter derived from soils and plants rather than in polluted waters.
