About the criteria of estimation of surface water quality of Kazakhstan on the basis of accounting of its natural features

Abstract

A literature review of the evaluation issues of existed methods and standards regulating the surface waters quality from the scientific and applied points of view is given. The problem of an objective and reliable assessment of the level of influence of anthropogenic factors on the quality of water resources has special relevance in the countries of the Commonwealth of Independent States (CIS). According to the number of leading scientists, mainly from the Russian Federation (RF), one of the significant insufficiency in the assessing of surface waters quality is the applying of uniform values of maximum permissible concentration (MPC) MPCsh and MPCfish established for the entire territory of the former USSR without taking into account the specifics of regional natural conditions and characteristics of water bodies. Within the territory of Kazakhstan the distortion of the actual state of surface water quality is becoming due to the use of the natural concentrations of the main ions and heavy metals in the calculation of the complex water pollution index (CWPI) by the Kazhydromet and not taking into account the wide distribution in the water bodies with brackish waters and ore-bearing areas. The validity of these statements is confirmed by examples from official publications. According to a common opinion of scientists, it is necessary to proceed the development of regional MPC because some methodological approaches have already appeared. It is recommended to develop a Temporary Methodological Guide for Surface Water Quality Assessment (prior to the establishment of regional water quality indicators) in Kazakhstan, excluding the main water ions from the calculated CWPI indicators, because they are not pollutants but natural components of the water composition.