Mining complexes, including mining and processing of minerals, are powerful sources of geodynamic, geochemical, physical, industrial and other types of environmental impact. Such large-scale impacts, along with the violation of the initial equilibrium state of the massif, cause a strong change in the environment of mining areas.
Among the districts of Kyrgyzstan that have experienced powerful technogenic pressure and tangible changes in the environment include the Sumsar-Shekaftarsky mining region [1,2]. In the villages of Sumsar and Shekaftar, located in the valley of the transboundary river Sumsar, the development of deposits of polymetallic and uranium ores was carried out in the second half of the last century. Many years of ore mining and processing activities have led to the formation of solid waste in these former mines located in dumps and tailings.
Until recently, the following were considered the key environmental risks that threaten the environment, safety and public health in the Sumsar-Shekaftarsky mining region:
- environmental pollution, primarily surface water, which is the most important determining factor in the economy and ecology of the region;
- the growing risk of physical destruction of tailings due to the threat of natural disasters (mudflows, landslides) and natural and technological disasters that are characteristic of the waste disposal areas in Sumsar and Shekaftar.
The greatest threats to the integrity and stability of tailings in the geodynamically active mountain regions of the Tien Shan are dangerous combinations of natural hazards or the so-called multi-risks (cascade processes), in which one or another dangerous natural phenomenon (for example, an earthquake, mudflow, abnormal precipitation and etc.) or a man-made accident give rise to a multi-stage chain of hazardous events that can destroy tailings and dumps located in riverbeds and river valleys.
The halo of the spread of pollution with this development of multi-stage processes expands significantly, including due to the spread and dispersion of contaminated hydrodynamic flows in the underlying densely populated foothill and valley regions . Similar scenarios of synergistic amplification of dangerous technological processes and accidents, their development into large-scale environmental disasters, occurred during accidental destruction of the dams of the tailings of radioactive waste located in the Mayl-Su and Kichi-Kemin river basins .
Ecologically hazardous facilities located in the area under consideration include the tailings of the former Sumsara mine. An ore complex for the extraction and processing of lead-zinc (Pb-Zn) ores was operated in Sumsar from 1951 to 1978. Ore mining was carried out until 1960 by open, and then underground method. There are three tailing dumps in the village with a total volume of about 3 million m3, covering a total area of about 265 thousand m2.
In the Sumsar Valley, there are tailing dumps of both alluvial and bulk types. It should be noted that in the difficult geological conditions of Kyrgyzstan, alluvial tailings turned out to be vulnerable to earthquakes and extreme atmospheric precipitation, which manifested itself in Sumsar in the form of gradual erosion and destruction of tailing dam No. 1. The collapse of the dam of this storage was accompanied by the release of toxic tailings into the riverbed. A sumar with the scattering of toxic tailings containing heavy metals on its outflow cone in Uzbekistan .
Individual geochemical risk, which are tailings in the river valley. Sumsar is clearly manifested in the area of the remains of the destroyed tailing dump No. 1. This risk is associated with the removal and dispersal of toxic “tails” and associated pollution downstream the river.
Analytical studies of the chemical composition of the tail materials of Sumsar, carried out in laboratories. Stefan and the Norwegian University of Natural Sciences, indicate that the tested tails contain rather high concentrations of heavy metals, in particular, lead (Pb) 1930-2380 mg / kg, zinc (Zn) 1880-2600 mg / kg, manganese ( Mn) 3030-4050 mg / kg, barium (Ba) 7420-11300 mg / kg, iron (Fe) 9190-10750 mg / kg, and toxic arsenic (As) 21.3-57.2 mg / kg, cadmium (Cd) 8.38-13.7 mg / kg, strontium (Sr) 409-491 mg / kg, copper (Cu) 14.3-17.7 mg / kg, cobalt (Co) 4.3-12, 7 mg / k).
In the area under consideration, the waters of the r. Samsar, especially floods and mudflows, often passing through it. Moreover, the transportation of toxic pollutants along the Sumsar River is inevitably carried out through the residential area of the villages of Sumsar, Shekaftar and other settlements in Kyrgyzstan and neighboring Uzbekistan. Initially, water and bottom sediments of the river are exposed to pollution. Sumsar. Contaminated water and river sediments spread downstream depending on the flow rate of the river at different speeds. The strongest direct impact will affect the population living in the village. Shekaftar, where people, firstly, drink water from a water intake located in the river basin. Sumsar, below tailing dumps No. 1-3. Secondly, they use river water to irrigate their vegetable gardens and gardens.
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