Abstract
The Srebarna Lake Biosphere Reserve is a protected natural site of national and international significance. It characterizes with extremely high biodiversity, being one of the last wetlands along the Lower Danube preserved in relatively natural state; the lake area is NATURA 2000 site. This study was designed to further research on the impact of intensive agriculture on the lake’s ecological status. First task was to find an evidence for link between intensive agriculture and the loading of the lake with nutrients. The second was a study on the PAH’s penetration into the lake ecosystem. An overview was made on drinking water data for 2 underground (drinking water springs). Dyakova spring’s water displayed good ecological state after measured parameters PO3-4 , NO2-3, NO- 2 and pH. Todorankina spring did not fell within the boundaries of good and very good conditions. Increased nitrate levels in water samples leads us to conclude that agriculture in this part of the surrounding area affect groundwater quality in the biosphere reserve. Results from GC-MS analysis proved, that there is no groundwater contamination, responsible for the existing (although low) concentrations of PAH found in the lake.