Ecological Systems and Devices Annotation << Back GEOZCOLOGICAL CHARACTERISTICS OF MODERN SEDIMENTS OF THE LAKE SELIGER NEARBY THE TOWN OF OSTASHKOV B.I. Korzhenevskiy, N.V. Kolomiytsev, G.Yu. Tolkachev, T.A. Ilina The lake Seliger is one of the natural attractions of European Russia. For many decades, this territory has been the object of expansion of both organized and unorganized tourists. Several dozen settlements and the city of Ostashkov have contributed and continue to contribute to the creation of a natural and man-made system in the territory under consideration. And although the population and the intensity of industrial production have some-what decreased in recent decades, the number of civilian objects, often located within water protection zones, has increased, which does not lead to an improvement in the geoecological situation. The consequence of this is the pollution of the sediments of the lake with heavy metals, which has been studied by the authors since 2000. As in other regions, the main polluter of the water area and sediments is the industrial complex. Several industrial enterprises of the city of Ostashkov, along with uncontrolled sources of pollution, have created a number of polluted areas of lake bottom sediments located near the city and not only. The most pronounced is the contamination with chromium, the «culprit» of which is a tannery that was actively working in the Soviet times, the activity of the negative impact of which has decreased in recent years. Monitoring of chromium contamination, the results of which show a very high degree of contamination in some points close to the source of its receipt, indicates the presence of «hot spots». The current state of the reservoir does not yet cause serious concerns about contamination with heavy metals, except chromium, but monitoring of this territory is necessary for a competent assessment of changes in its geoecological state. Keywords: Lake Seliger; geoecological situation; sediments; pollution; heavy metals; chromium; igeo-classes; zoning. DOI: 10.25791/esip.1.2022.1278 Pp. 15-23.