Assessment of the Total Amount of Surface Deposited Sediments in Small Towns

Local surface-depressed areas in an urban microrelief are geochemical traps for sediments deposited at the surface. These sediments accumulate pollutants over space and time. The aim of this study was to estimate the total amount of surface sediment in residential areas of small towns with different industrial specialisations. Snow-dirt sludge, snow, and surface sediment samples were collected in towns of the Sverdlovsk region, Russia: Alapaevsk, Kachkanar, Serov, and Verkhnyaya Pyshma. Snow and snow-dirt sludge were collected in the cold season, and surface sediment was collected in the warm season. This study was carried out in 2024. The solid matter of the samples was divided by sieving into particle size fractions: dust (<0.1 mm), fine sand (0.1–1 mm), and coarse sand (1–3 mm). The method used to estimate the total amount of sediment took into account data on the concentration of solid matter in snow-dirt sludge, the volume of melt water, and the contribution of the dust fraction in surface sediment and residential areas. The concentration of solid matter in snow-dirt sludge was about the same in the three cities (up to 6.6 g/L), but differed significantly in Kachkanar (60 g/L). The total amount of surface sediment per unit area was about the same in the three towns (1.1–1.4 kg/m2), but differed significantly in Kachkanar (10.8 kg/m2). The contribution of the dust fraction to the total amount of sediment was estimated to be 10–20% in the cities. The total amount of surface deposited sediments in the residential areas of the small towns was 1.6 × 107 t in Alapaevsk, 5.9 × 107 t in Kachkanar, 1.7 × 107 t in Serov, and 1.3 × 107 t in Verkhnyaya Pyshma. The values obtained for the total amount of surface sediments characterise the contemporary sedimentation processes in residential areas and the environmental quality of small towns.