The Influence of Microbiological Processes on Subsurface Waters and Grounds in River Dam Basement

Abstract

Microbes are ubiquitous on the Earth and take an active part in the transformation of the geological environment. Their activity can change the geochemical parameters of ground and groundwater and lead to undesirable consequences after the building of hydrotechnical facilities, especially pressure ones. The geological and chemical survey of one of the ground dams of Kama–Volga rivers cascade (The Ural, Russian Federation) revealed the unusual deviations in chemical content of drain water and the presumable suffusion process at the dam basement. The aim of our study was investigation of the dam’s ground and water to reveal another deviations in their characteristics, which in turn could help to assess the stability of the dam. We investigated the composition of water-dissolved organic matter (gas chromatography–mass spectrometry analysis), the composition of subsoil gases of the dam (gas analysis), and performed mineralogical analysis of sediments settled at the bottom of the dam’s drain system (X-ray diffraction analysis); chemical analysis of water of various aquifers under the dam basement was performed too; also, the microbiological investigations of the dam’s ground and water samples were made. We suppose, the results of investigation demonstrate the presence of an active microbiota in dam’s ground and water, and microbiota metabolism could lead to hazardous changes in physical-mechanical properties of dam’s ground and, eventually, the unstable state of the dam itself.