In the frame of the project Water Supplying of the Cities and Protection of the Groundwater Quality in the Velika Morava Valley, was obtained the analysis of potential polluters of groundwater source of city Smederevska Palanka - Trnovce. This paper presents results of water physical, chemical and microbiological characteristics of soil. According to the results of research and way of usage of the soil, it was concluded that agricultural production does not have negative influence on quality of the groundwater source.

Protection of raw water quality at the water source is delicate and often very expensive. As it is known, the majority of hydrotechnical structures are complex and big in both technical and financial terms. This paper is aiming to show necessity to provide, if possible, multipurpose use of these structures in order to reduce and distribute the costs.

In this paper the results of zooplankton investigations (and its dominant group Copepoda) were presented from the part of the Boka Kotorska Bay with more intensive circulation with the open sea, from summer of 2005. Some results from the open South Adriatic were given, too - from the frontal zone exposed to anthropogenic eutrophication of Bojana and Drim rivers, and the impact of oligotrophic South Adriatic, simultaneously.

In this paper, results of phytoplankton investigations were performed in June 2005. The investigated positions are located near the entrance of Boka Kotorska Bay: two positions in the outer part (Zanjica and Mamula island) and two positions in the inner part of the Bay (Njivice and Tivat bay). In this area the influences of the open sea and the land are expressed to the phytoplankton community. As a consequence of that quantities of phytoplankton are lower in the outer part and higher in the inner part. The most dominant species is diatom Pseudo-nitzschia delicatissima which is very frequent in the eutrophic area.

Determination of total arsenic and As(III) was performed in untreated and treated water samples collected in some small water supply systems in Northern Backa district (Serbia). Concentration of total arsenic in treated water was between 71 and 115% of total arsenic in untreated water (0.001-0.168 mg As/cubic dm). In untreated water concentration of As(III) was between is less than 0.001 and 0.078 mg As/cubic dm. However, during the water treatment (chlorination process) As (III) concentration decreased significantly to the level of 1 to 2% of start concentration in untreated water. Influence of conservation water sample with HCl increased with consumption of KMnO4 on determination of As(III).