Quantitative assessment of biogenic elements and suspended matter load to inner-city river: the role of point sources and diffuse runoff

Abstract The article provides a quantitative assessment of the input of biogenic elements and suspended matter in the composition of the storm sewer outlets from the territory of the Kazan City (Russia, the Republic of Tatarstan) and the diffuse runoff of biogenic elements from the agro-developed catchments into the Kazanka River (left tributary of the Volga River) as the main risk factors for the development of anthropogenic eutrophication processes. Based on the results of long-term monitoring and the current background concentrations of total phosphorus, nitrogen and suspended solids in the recipient river, determined in the work, the impact of storm water discharge on surface waters within the Kazan City was assessed. The values of permissible loads of phosphorus and nitrogen mineral fertilizers on an agriculturally developed catchment are given for regulating the diffuse runoff of nutrients into a water body, depending on the hydrometeorological conditions of the territory, to a level that meets the basic environmental requirements for the quality of surface waters.