Impact of illegal dumping sites on the groundwater of Ljubljansko polje

Due to dense settling and the concentration of numerous economic and other activities, gravel aquifers are threatened. The key conflict on Ljubljansko polje is between the need to protect the groundwater as a source of drinking water for the supply of Ljubljana on one hand and agriculture and various urban-related activities on the other. We used a survey to register and study 1,445 illegal dumping sites in the narrowest and narrow water protection areas, of which Jarški prod on the left bank of the Sava River near Črnuče, the most problematic area, alone has 151 ones. The total surface area of the studied illegal dumping sites amounts to 120,816 m2, and their total volume is 209,422 m3. In the area surveyed, we also registered 100 gravel pits, 58 information signs, and 57 road barriers. Two thirds of the waste consists of construction material. A good seventh of the waste is hazardous waste. On Jarški prod, the total surface area of the waste is 26,273 m2, which means that waste covers 1.2 % of the area. This makes Jarški prod one of the most waste-contaminated areas in Slovenia. An average dumping site on Ljubljansko polje measures 178 m2, and the total volume of waste amounts to 42,464 m3. Using a carefully developed methodology, we have planned a priority schedule for the remediation of illegal dumping sites.