THE ROLE OF TECTONIC FACTORS IN IMPROVING THE ENVIRONMENTAL SAFETY OF TAILINGS PONDS

Abstract

Over the past three decades, there has been growing concern worldwide about environmental degradation caused by the large-scale displacement of hazardous materials as a result of tailings pond accidents. As of 2020, there are 465 tailings ponds in Ukraine, containing over 6 billion tonnes of waste from various industries. Given the global nature of the problem and its relevance to Ukraine, there is a need for a systematic review of all aspects related to the creation, operation, closure of these facilities and compliance with modern environmental and industrial safety requirements. Causes of tailings pond accidents: overfilling of the design capacity; violation of the stability of the slope (dam) and structural integrity of the tailings pond elements, primarily drainage or pipelines that transport tailings materials; earthquakes and other seismic events; violation or instability of the tailings storage facility foundation; filtration through the dam body; erosion of the surface and dam body due to adverse weather conditions; subsidence due to mining operations. Particularly dangerous are factors that lead to a breach in the stability of the slope (dam) and the structural integrity of the radioactive waste tailings pond elements. Studies conducted using geophysical methods of the Earth’s natural impulse electromagnetic field and vertical electrical sounding at the Dniprovske radioactive waste tailings pond in Kamyanske have identified areas of waterlogging and filtration in the containment dam and cracks in them. These zones and the azimuths of the cracks spatially coincide with the fault structures and their azimuths on the latest geotectonic maps of the area. Thus, a new tectonic factor has been identified that affects the technical condition of tailings ponds and civil hydrotechnical structures (HTS) during their long-term operation: the manifestation of hidden fracture zones in tailings dam embankments and civil HTS is subject to the trends of modern tectonic movements, which, under conditions of long-term operation of such structures, will contribute to the emergence of weakened zones and provoke the development of dangerous processes that will lead to a decrease in the reliability of HTS. This factor must be taken into account when designing new HTS and during visual and instrumental surveys of tailings dams in long-term operation.