Water protection areas cover 3532 km² or 17,4% of Slovenia’s land surface in 2021. This is a slight increase, compared to 2017, but the goal of protecting the areas of all water sources for public water supply with a regulation on national level, has not been reached yet.

In recent years, ambient concentrations of ozone in urban and suburban areas has been above target value for human health protection. Long-term targets have been exceeded at almost all measuring sites. Due to fewer hot sunny summer seasons, the information threshold levels have been exceeded only in the Primorska region and in some places at higher altitudes - Otlica. However, also some exceedances have been recorded at measuring sites that are not directly exposed to traffic.

In Slovenia, nutrient overloading is still the basic problem concerning lakes and reservoirs, and from 2006 to 2019, no improvement is observed. In the assessment period 2016–2019, only 4 out of 11 lake water bodies were determined to be in good or very good trophic status. Overloading of lakes with phosphorus is usually a result of inadequate wastewater drainage and intensive agriculture in the watershed area.

Groundwater is most polluted in aquifers with intergranular porosity in the northeastern part of Slovenia.

Concentrations of nitrogen dioxide and total nitrogen oxides in ambient air do not exceed the prescribed limit values. Consequently, they are not harmful for human health and vegetation.