Evaluation of Groundwater Salinization Risk Following Application of Anti-Dust Emission Solutions on Unpaved Roads in Arid and Semiarid Regions  
Meni Ben-Hur  
1 Institute of Soil, Water & Environmental Sciences, ARO, Volcani Center, Rishon Lezion 7505101, Israel; [EMAIL_ADDRESS] ([PERSON]. [PERSON] [12] tested the effectiveness of the lignin, resin, bitumen, PVA, and brine application in preventing dust emission by wind from unpaved roads. These tests were conducted under controlled laboratory and field conditions, using wind tunnels with varied wind velocities and time durations. It was found in this experiment that among the tested anti-dust emission solutions, brine from the Dead Sea was the most effective solution in preventing the dust emission; the brine application decreased the dust emission by >90% of the dust emissions under the control treatment [12]. Arid and semiarid regions are characterized by a long dry season and a short wet season with limited precipitation. Thus, natural water resources, such as groundwater and non-salty surface water (fresh water, FW) in these regions, are scarce [13]. Moreover, the climate conditions and the high population growth in these regions lead to an escalation of irrigation with low quality water, such as treated wastewater (TWW) and saline water [13], which increases the salinization of the water sources in the region [13]. Most of the haul roads in mines and quarries are unpaved roads covered with a layer (usually 20-30 cm thick) of calcareous granules (granular material) that sensitive to dust emission. A common practice to prevent the dust emission from these unpaved roads in arid and semiarid regions, such as Israel, is the application of hyper-saline solution (brine) on the unpaved roads. In recent years, concerns have been raised regarding the application of the brine solution on unpaved roads for controlling dust emission. It was claimed that the application of the brine solution with very high salinity will further increase the salinization of the water resources. Indeed, some quarries use FW instead of brine solution in their anti-dust practices. However, since FW is scarce in arid and semiarid regions, TWW is also used for the purpose of anti-dust emission on unpaved roads. The TWW is characterized by moderate salt concentration, particularly Cl and Na ions; high concentrations of toxic, inorganic macro- and micro-elements, such as NO\({}_{3}\), boron and heavy metals; and high contents of suspended and soluble organic matters, including organic pollutants and pathogens [13]. The brine solution, however, is characterized by very high salt concentration, particularly of Cl, Ca, and Mg ions, and a high concentration of toxic heavy metals, such as Ni, Co, Cd, and Pb. Therefore, during the rainfall season, high concentrations of salts and toxic elements and compounds could be leached from the unpaved roads treated with TWW or brine solutions and salt, and contaminate the water sources. The present study is focused on the salinization of water sources following the application of anti-dust emission solutions on unpaved roads. The trend of using FW or TWW as anti-dust emission solutions instead of brine solution in arid and semiarid regions is based on the assumption that a decrease in the salinity of the anti-dust emission solution will necessarily decrease the salinization of the water sources in the region. However, the salinization of the water sources, under the application of anti-dust emission solutions, is dependent on varied factors other than the salinity of the anti-dust emission solutions. Therefore, the general objective of the present study was to investigate the effects of the application of TWW, FW, and brine solutions on unpaved roads as anti-dust emission solutions on the salinity of the water resources in arid and semiarid regions, such as Israel. The specific objectives were to determine or estimate the effects of the application of TWW, FW and brine solutions on the following: (i) The accumulated amounts of the solutes on the unpaved roads.