Assessment of quality of water and sediments in small reservoirs in Southern Poland - A case study

The paper presents an attempt to forecast heavy metal pollution of sediments of four designed reservoirs in southern Poland. For this purpose, concentration of dissolved heavy metals (lead, cadmium and nickel) was determined in water of watercourses on which the designed reservoirs will be constructed and also in sediments and water flowing into six reservoirs that are already in use. Based on the results of the heavy metal concentrations of six exploited reservoirs, a relationship was developed between heavy metal concentration in the sediment as a function of the concentration of these metals in the inflowing water. Using these relationships, the forecast concentrations of these metals in the sediments of the designed reservoirs were estimated. The mean concentrations of these metals in the planned reservoirs were 20.5 mgkg(-1) for lead, 3.4 mgkg(-1) for cadmium and 14.8 mgkg(-1) for nickel. No dangerous pollution of analyzed metal of water inflows to the planned reservoirs was found. The calculated geoaccurnulation index indicates that in terms of the lead and nickel concentrations, sediments in the planned reservoirs will be unpolluted to moderately polluted, while for cadmium concentrations - they will be moderately to strongly polluted.