Sustainability Report 2012 Lek d.d.

39 Environment 52 RC KPI 15 53 RC KPI 16 Graph 7: Emissions of phosphorus compounds in wastewater 52 Graph 8: Emissions of nitrogen compounds in wastewater 53 Emissions of phosphorus compounds in wastewater Emissions of nitrogen compounds in wastewater 2.7.2 Phosphorus and nitrogen compounds, chemical oxygen demand Nitrogen compound emissions mostly result from the fermen- tation production, particularly at the Menge‰ site followed by Lendava and Ljubljana, and, at a negligible level, the Preva- lje site, which is demonstrated in the graphic presentation of the emission trends by site. In 2012, the total volume of nitrogen compound emissions at Lek declined. The Menge‰ site is also the major generator of phosphorus compounds, their source being residual inorganic substances. As the annual amounts of phosphorus and nitrogen compoun- ds are reported after treatment in the wastewater treatment plant, they largely depend on the efficiency of the wastewater treatment. In 2012, they rose to the level of 2008. To provide an assessment of the level of pollution with orga- nic impurities, chemical oxygen demand is an important para- meter, providing the quantity of oxygen needed for chemical oxidation of organic pollution in wastewater. Chemical oxygen demand measurements aimed at assessing the pollution le- vel are carried out at the point of discharge of waste cooling waters into the water stream, and at the point of discharge of industrial wastewater into the treatment plant collector. The level of chemical oxygen demand declined in 2012. Lek’s wastewaters and the content of all the three parameters are constantly monitored by the authorized monitoring autho- rities. Monitoring is carried out three to six times a year, de- pending on the volumes of wastewaters at the respective site. Chemical oxygen demand, total phosphorus compounds and total nitrogen compounds in wastewaters also constitute pa- rameters for the calculation of the environmental fee. The hig- hest impact, accounting for more than 80%, is associated with chemical oxygen demand, whereas phosphorus and nitrogen compounds each represent about 10% of the pollution. Lendava Lendava Ljubljana Ljubljana Menge‰ Menge‰ Prevalje Prevalje 2.5 2008 2008 2009 2009 2010 2010 2011 2011 2012 2012 2.0 20 3.5 3.0 1.5 18 16 14 12 1.0 8 10 0.5 4 2 6 0.0 0 t t Year Year