The article deals with the problems of transboundary surface waters on the example of the Tobol River. The assessment of the quality of water resources according to hydrochemical parameters was carried out in accordance with generally accepted standards of maximum permissible concentrations of harmful substances for water of fishery bodies of water. The study established the excess of ammonium nitrogen standards of 1.3 - 3.03 MPC; nitrite 2.8 - 26.4 MPC; total iron 6.2 - 17.3 MPC; copper 4.31 - 9.55 MPC; zinc 1.7 - 10.8 MPC; phenols 7 - 10 MPC; petroleum products 2.6 - 26.8 MPC; the content of organic substances (biological oxygen consumption in 5 hours) was 1.22-4.29 mg / l, while the MPC was 2 mg / l. According to the complex ecological classification of surface water quality according to O.P. Oksiyuk and V.N. Zhukinsky degree of pollution of water resources corresponds to the class from «polluted» to «extremely dirty».