The establishment of detailed monitoring of quantitative and qualitative parameters of groundwater in the zone of possible interactions between a water-conveyance tunnel and the geologic/hydrogeologic environment is of the utmost importance for assessing the risk of adverse effects and of tunnel performance. The water-conveyance tunnel of the Pirot Hydropower Plant (HPP Pirot) is a good example of applying detailed monitoring in complex geologic/hydrogeologic conditions resulting from the presence of an underground structure. The research scheduling was conditional upon the operating regime of the tunnel (whether it is in or of operation—online or offline). While the tunnel was operating (online), monitoring was conducted at observation wells along the tunnel (approx 15 m distant), a control gate (water losses), springs, and a stream in the vicinity of the tunnel. Areas of the potential hydraulic instability were indicated by synchronous measurements of water level and temperature changes in the observation wells and at the control gate. While the tunnel was offline (empty tunnel) it was possible to access the tunnel, and in situ monitoring proved to be of great importance. Observations of quantitative parameters pointed out hydraulically critical tunnel zones, whilst the qualitative characteristics of groundwater revealed their potential aggressiveness to the concrete lining of the tunnel. The applied methodology shows that a detailed observation program should be an important task of sustainable tunnel management.

The monitoring and analysis of concentrations of toxic metals (lead and cadmium) in soils and crops indicate that farmland in Serbia is generally not polluted, and the quality of soils is naturally good. Such soils are therefore suitable for organic farming. All noted instances of contamination by toxic metals are of a local nature only, and the result of fertilizers and pesticides, municipal waste, exhaust gases, nearby production facilities, smelting plants, mines, tailings ponds, etc. Locations of this type need to be monitored regularly, and the status of the soil and crops assessed. The results presented in this paper place special emphasis on lead and cadmium. In this regard, the sampling of 67 plant foodstuffs that are being grown in Baroševac village, located in the immediate vicinity of the Kolubara coal mine, was carried out. Fruit samples represented 14.9% and vegetable samples 85.1% of the total sample. The heavy metal content (lead/cadmium) in seven samples was above the limits prescribed by the Regulations. Overall exposure of the adult population of Baroševac, calculated on the basis of all samples (67 in total), was 0.89 µg lead per kg of body weight per week, representing only 3.5% provisional tolerable weekly intake (PTWI), and 0.46 cadmium per kg of body weight, which amounts to 6.7% PTWI. Both values point to the fact that the risk is low, even in the case of populations with high exposure to these toxic metals. This suggests that sustainable development may be possible in the near future.