Water Quality Assessment Based on Chemical and Biological Characteristics: An Example of Classification of Characteristics for the Cheremushnyi Creek–Yenisey River Water System

A six-class scale for a complex classifier of water quality is applied to the Cheremushnyi Creek–Yenisey River water system. The classifier incorporates a chemical index of water pollution and biological characteristics with autotrophic and heterotrophic periphyton groups and macrozoobenthos used as biological indicators. The oligochaeta index and Woodiwiss biotic index are shown to have low indicator capacity. Bioassay studies were based on recording acute and chronic toxic effects for three test species at different trophic levels. The level of biologically safe dilution is proposed as a quantitative index of toxicity. Saprobity and toxicity (saprotoxobity) characteristics are given for individual species. Water of the Cheremushnyi Creek–Yenisey River water system is referred to the IV–VI quality class.