1. curriculum in natural environmental science, vol. 2, 2010 Institute of Water Supply and Environmental Protection Cracow University of Technology Krakow, ul. Warszawska 24, 31-155 Poland Reservoirs as a trap for pollutants Ewa Szalinska Krakow University of Technology, Krakow, Poland

2. Outline: Reservoirs as traps for sediments Consequences of sediments trapping Risk related to the contaminated sediments Case study: Czorsztyn Reservoir

3. Reservoirs as traps for sediments “The ultimate destiny of all reservoirs is to be filled with sediment” (Linsley et al. 1992) Source: www.usace.army.mil Trap efficiency – around 80-90%

4. Sediment as sink for contaminants Sediment properties: fine fraction clays organic C cation exchange capacity pH Processes : adsorption absorption ion-exchange Co-precipitation complexation chelation

5. Consequences of sediments trapping Loss of the reservoir volume Accumulation of sediment-associated contaminants Major contaminants of sediments: – Nutrients – Bulk Organics – Halogenated Hydrocarbons or Persistent Organics – Polycyclic Aromatic Hydrocarbons (PAHs) – Metals

6. Risk related to the contaminated sediments Possibly toxic for the invertebrates and fish Sediment-associated contaminants can be bioaccumulated Direct exposure for humans Impaired human uses Source: McDonald & Ingersoll 2002

7. Case study: Czorsztyn Reservoir Photo: T. Zabrzewski

8. Localization Map source: http://www.zzw-niedzica.com.pl/; Photos: E. Szalinska

9. Monometallic contamination in the sampling area 300 local tanneries Cr as a tanning agent Map source: http://www.zzw-niedzica.com.pl/; Photo: E. Szalinska

10. Temporal distribution of Cr in the upper Dunajec River sediments (2000-01) Source: Szalinska et al. 2003

11. Spatial distribution of Cr in the upper Dunajec River sediments (2000-01) Source: Szalinska et al. 2003

12. Conceptual schema of Cr transport in the Dunajec-Czorsztyn system After Dominik et al. 2007 RiverReservoir dissolved Cr particulate Cr(III) Cr(III) adsorption coagulation sedimentation settling aggregates HMWC LMWC aggregation colloids Cr(VI) precipitation poly-Cr(OH) 3

13. Source: Wachałowicz, unpublish. Spatial distribution of Cr in the Czorsztyn Reservoir sediments (2006)

14. 0,130 0,012 0,120 1 % 13,8 % ChromiumOrganic matter Source: Wachałowicz, unpublish. Spatial distribution of Cr and organic matter in the Czorsztyn Reservoir sediments (2006)

15. Source: Szalinska et al., in prep. Budget of Cr for the Czorsztyn Reservoir Lack of precise data about Cr discharges; Cr load estimated on the basis of WWTP data and water sampling results; Suspended matter as a vector in the Cr transport (9  3 Kt/yr) Total Cr load calculate with use of partition coefficient K d (8  4 t/yr)

16. Further reading: Benett & Rhoton 2007. Reservoir Sedimentation and Environmental Degradation. Assessing Trends in Sediment-Associated Trace Elements in Grenada Lake, Mississippi. J Environ Qual. 36:815-825 Dominik et al. 2007. Speciation and environmental fate of chromium in rivers contaminated with tannery effluents. Engineering in Life Sciences, 7(2):155-169. MacDonald & Ingersoll 2002. A guidance manual to support the assessment of contaminated sediments in freshwater ecosystems. EPA- 905-B02-001-A. Metre & Mahler 2004. Contaminant trends in reservoir sediment cores as records of influent stream quality. Environ. Sci. Technol., 38:2978- 2986 Pye (ed) 1994. Sediment transport and depositional Processes. Blackwell Scientific Publications Sundborg A. 1992. Lake and reservoir sedimentation. Prediction and interpretation. Geogr. Ann. 74A:93-100 Szalinska et al. 2003. Fate of tannery chromium contamination in a stream: Temporal and spatial evolution of chromium(III) and chromium(VI). J. Physics IV, 107:1275-1278