# Review of the Failure at the Flotation Tailings Storage Facility of the \"Stolice\" Mine (Serbia)
## 4 Accident Consequences  
During the accident, a total of between 70,000 and 100,000 m\({}^{3}\) of the deposited tailings spilled from the TSF, with most of the tailings spilling from the eastern field [20]. The beds of the Kostajnicka River and the Korenita River were devastated, especially the unregulated parts of the riverbeds. The spilled tailings were deposited on the banks of the Kostajnicka River, spanning 5 km, and the Korenita River, spanning 20 km, up to the confluence with the Jadar River [11]. Downstream from the TSF, deposits of spilled tailings were created, which were 5-10 cm thick and 50-75 m wide (Figure 8a,b) [21]. It has been estimated that the total contaminated surface of the arable and non-arable land was around 400 ha. Road No. 149 was completely closed off, and several residential buildings were completely demolished [10]. There were no human casualties [5]. Figure 6: The improvised wooden embankment of the eastern field. Reproduced with permission from the Water Institute “Jaroslav Černi” [10]. Figure 7: The temporarily blocked eastern tailings field was breached again on 17 July 2014. Reproduced with permission from N1 Television [19]. According to the Report on the State of the Environment in the Republic of Serbia in 2014 [22], the results of the analysis of agricultural land samples near the TSF showed elevated concentrations of As (4118.9-4560 mg/kg), Cd (9.5-13.4 mg/kg), Pb (385-448 mg/kg), Zn (1221.4-1630 mg/kg), and Hg (6.3-10 mg/kg) according to the Regulation on the programme of systematic monitoring of soil quality via indicators for assessment of soil degradation risk and the methodology for the creation of remediation programmes (\"Official Gazette of the RS\" No. 88/10 of 23 November 2010) [23]. According to [24], in 95% of the soil samples that were taken in the flooded area in 2017, it was found that the remediation value, according to the regulation [23], which for Sb is 15 mg/kg, was exceeded 18 times, while the remediation value for As (55 mg/kg) was exceeded 8.5 times 3 years after the accident; while [25], in their research in 2018, proved that the Sb, Hg, Pb, Cd, and Zn contents, as well as the pollution index, decrease with distance from the TSF. Based on information about the content, distribution, and appearance of microelements, especially potentially toxic (As, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se) and radioactive ones, different impacts on the environment and human health can be predicted. Studies have shown that certain amounts of Cd, As, Cr, and Ni cause cancer in humans, while Be, Cd, Co, Cr, Mn, Ni, and Pb have a carcinogenic effect on animals [26]. In previous research, it has been observed that the ions of certain microelements isomorphically replace the \"host metal ions\" in soil minerals. For example, in the crystal lattice of clay minerals, vanadium easily replaces aluminum, and in goethite (a ubiquitous hydrated iron oxide), the Fe\({}^{3+}\) ion can be isomorphically replaced by Cr\({}^{3+}\) Ni\({}^{2+}\) Cu\({}^{2+}\), Zn\({}^{2+}\), Cd\({}^{2+}\), or Pb\({}^{2+}\) ions. The calcium ion in calcite is relatively easily replaced by Zn\({}^{2+}\), Sr\({}^{2+}\), Ba\({}^{2+}\), and Pb\({}^{2+}\). Rubidium and cesium, like potassium, have a high affinity to be Sorbed even irreversibly in the interlayer spaces of clay minerals, montmorillonite, and illite. Ions of microelements are Sorbed into the primary and secondary layers of colloids and participate in ion exchange reactions. As in the case of macroelements, the affinity for sorption increases with the increasing charge and increasing radius due to a lower degree of hydration. Co-precipitation with carbonates, which is the most widespread calcite, is a very significant mechanism in the immobilization of heavy metal ions, especially when it comes to Zn, Cd, and Sr [27].