The results of the hydroecological study of the small Oskolets river in the area of influence of mining enterprises are presented. It is shown that the residential industrial flow of Gubkin city has a leading influence on the hydrochemical situation. Discharges of drainage waters made by the Lebedinsky mining and processing plant have a definite impact on the hydro-ecological situation with respect to the content of fluorine and lead compounds, and occasionally with respect to nitrogen compound