**2. Groundwater pollution in Slovenia—the background**

 Slovenia is not a big country at just over 20,000 km<sup>2</sup> . It is, however, very diverse in terrain and climate. In north-west, it touches the Alps, in south-west, the Adriatic Sea, and in north-east, the Pannonian Basin. Except for the latter part, most of its relief consists of hills and mountains, and the only larger flat areas are alluvial plains, whose aquifers serve as storage for the majority of country's groundwater. Climate follows the characteristics of terrain, which means that the western parts of the country get 2,000 and up to 3,000 mm, while the north-east can get as little as 800 mm of rain in a year. The abundance of rain is the main reason for Slovenia's groundwater capacities, but the seasonal variability in recent years is not best suited for agriculture, as peaks are moving more and more into autumn, while in other seasons, rainfall is diminishing [1].

 As mentioned above, main reservoirs of groundwater are located under alluvial plains. These are also centers of agricultural production, with intensive arable rotations and vegetable fields, but in some areas also orchards. According to National Environmental Agency (ARSO), the main problematic areas are Murska kotlina, Dravska kotlina, Savinjska kotlina, and Krška kotlina, labeled in top to bottom order in **Figure 1** with an exclamation mark sign. It is quite easy to notice that they share a similar type of an aquifer, and the depth from ground surface to it is often times as shallow as 1–2 m. Views from Murska kotlina and Krško polje can be seen in (**Figures 2** and **3**).

Speaking of pollution, there are various different substances causing it. As mentioned before, nitrate is one, but certainly not the only troublemaker. Pesticides can also pose significant threat, and in Slovenia, atrazine is the most common of them. In its reports, ARSO also mentions other pesticides, like bentazone, terbutilazine, isoproturon, chloridazon, etc., but these are mostly just detected, and do not pose

#### **Figure 1.**

*Map of Slovenia with different aquifer types; blue color mostly corresponds to the main alluvial plains.* 

*Groundwater Protection Legislation in Slovenia: Theory and Practice DOI: http://dx.doi.org/10.5772/intechopen.83664* 

**Figure 2.**  *Corn harvest on Murska kotlina plain (photo: Curk, 2017).* 

 any threat. Atrazine and its metabolite desetil-atrazine are still found in quite high concentrations though, in places well above the EU threshold of 0.1 μg/L. What is interesting is that, despite atrazine being banned in EU (or rather its registration was not renewed) more than 15 years ago, it is still present in our groundwater (**Figure 2**).
