Approaches to the identification of the origin of heavy metals in bottom sediments and standardization problems: Case study of two SDPP reservoirs in ural region

Concentrations of seven metals in bottom sediments of water-cooling reservoirs of Yuzhnoural’skaya and Troitskaya SDPPs, as well as of less polluted Verkhneural’skoe Reservoir (Chelyabinsk province) are studied. Small samples taken during one season were used as an example to consider three variants of data analysis: comparison with regional control, search for pair correlations between metals, and multidimensional approach. The usefulness of factor analysis for revealing the sources of metals supply to water bodies is demonstrated. The origin of three identified groups of metals is considered from the viewpoint of SDPP operation (for Fe and Pb), correlation with organic matter (for Cu, Zn, Mn), and washing out from nickel-bearing components of soil (for Ni and Co). The problem of choice of monitoring indicators corresponding to the objective of the study is discussed.