Industrial environmental control over development of oil fields is the main tool of geoecological monitoring. Because of the man-induced impact associated with upstream activities, monitoring of the state of surface hydrosphere is of most interest. In the framework of ecological-hydrogeological surveys on the territories of Tatneft PJSC upstream activities on the south-western slope of the South-Tatarian Arch, hydrological monitoring of the fluvial network in the south-eastern part of Tatarstan has been carried out. Because of the advancement of the monitoring system, the list of determined micro components in water was expanded. Determination of the content of manganese, iron, copper, zinc, and nickel provided information about concentration of heavy metals, which top the list of toxicological hazards. Besides, assessment of the current environmental state requires that background concentrations of heavy metals on the exploratory prospects shall be registered. Analysis of heavy metals content in surface waters on the territory of the company’s operations as of 2018 was performed. Quality of water in the Stepnoi Zai, the Sheshma and their stream tributaries was assessed in quantitative terms using the water pollution index (WPI). Water in the Stepnoi Zai was classed as polluted (class of quality IV), water in the Sheshma was classed as moderately polluted (class of quality III). In the stream tributaries WPI is higher as a rule. The survey results indicate marked override of heavy metal concentrations in the Stepnoi Zai, the Sheshma and their stream tributaries. Component analysis along the thalweg of the river stretches under survey was performed. Content of all metals increases in the Sheshma left-bank tributaries from the river mouth to the river source. Principles of forming of heavy metals and mechanisms of their entry into rivers were studied. Mainly, heavy metals naturally migrate from soils in the south-east of Tatarstan characterized by high background concentrations of manganese, chrome, copper, zinc, nickel, and cobalt. The man-made heavy metal source was studied by the example of the Stepnoi Zai. It was found that concentrations of some metals increase after waste water disposal because of poor performance of effluent treatment facilities.
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