Environmental Characteristics by Eco-Sanitary and Toxic Criteria of the Cooling Pond of Zaporizhzhya Nuclear Power Plant (Ukraine)

It has been investigated the ecological status of the cooling pond of Zaporizhzhya Nuclear Power Plant (NPP) on the hydrochemical and toxicological indicators. The ecological water quality by most hydrochemical and hydrophysical indices corresponds to the class II, category 3, and is characterized as "fairly clean". However, according to the BOD5 index, the water quality is "satisfactory" (class III, category 4). By the contents of both nitrogen of nitrates and phosphorus of phosphates the water quality belongs to the class IV, category 6, as "bad, dirty water". The main anthropogenic pollutants are copper, iron, zinc, and fluorides. The ecological characteristics by their concentrations in the water correspond to the class III, and categories 4–5 of quality, which are "poorly and moderately polluted" water. Accumulation of toxic metals in the surface layer of the reservoir bottom sediments depends on their types, the minimal content is found in sandy sediments, and maximal one is in muddy sediments. The possibility of significant secondary pollution of the water environment by toxic metals is small under the hydrophysical and hydrochemical conditions typical for the cooling pond of Zaporizhzhya NPP. According to the calculations, the value of the average chemical index of ecological quality is "2.5", which characterizes the water of the Zaporizhzhya NPP cooling pond as "good" and "clean".