In Serbia, in the most cases, drinking water supply is based on alluvial sources. The appearance of nitrate in some important alluvium aquifer has been observed and an increasing of this problem can be expected with a currently tendency for intensifying the agricultural production. Therefore, the used techniques which are able to identify the source of nitrate in groundwaters and existing processes of its reduction will be more and more requested. Simultaneously determination of both nitrogen and oxygen isotopic fingerprints allows us to make a difference between nitrate from artificial fertilizer and manure or animal waste as well as nitrate formed from nitrification of organic material and consequently the dominant source of the nitrate to be indicated. Once the origin of nitrate in drinking water sources is understood, corrective measures may be taken to prevent or minimize further contamination.

One of the biggest problems in drinking water treatment is the presence of a high natural organic matter (NOM) content in water resources. This paper presents the results of a study which aimed mainly to determine a combined coagulation and preozonization process application for trihalomethanes and haloacetic acids precursors content in ground water rich in natural organic matter.

Quality of irrigation water taken from three wells located at Rimski Sancevi near Novi Sad, Serbia, has been monitored for three years. The obtained results showed that the samples from the three wells had a relatively uniform quality. We are dealing with a mineralized water which may increase the salinity of poorly drained soil but it cannot cause soil alkalization because of low sodium levels. In view of the above, it is recommended to periodically check not only irrigation water quality but also soil salinity level.

In this paper there are presented the results of organic matter index, as dominant component of unsettled water of settlement, which after specified time locate into deeply karst underground appear on spring of river. Obtained results showed that into deeply karst underground has become to certain level of autopurification, which reflecting values of index this loading on the water of spring - river.

Since the water from the intergranular aquifer of Cemovsko Polje (Montenegro) represents an invaluable drinking water reserve, which can also be used for irrigation, the check up of the aquifer revealed that it is being infiltrated by pollutants from somewhere within the catchment area. The results have shown that the mentioned water from the intergranular aquifer (T3 and T4) is influenced by the agricultural activities in the area, leakage from the uncontrolled landfill of Podgorica, depending on the hydrological conditions, and, to a smaller degree, by the quality of the surface waterflows, with which it is connected.

Water wells are among the oldest hydraulic engineering structures in the world. Today, hundreds of water wells service water supply systems in Serbia, and groundwaters are widely used for public water supply. Extensive practical engineering experience in water well operation has identified a number of problems which affect well service life and capacity (i.e. reduce specific yield). Some of the encountered problems are, also, a result of microbial activity in groundwater. Products of life processes of groundwater specific microbial community cause biocorrosion, blockage, closure, plugging, deposition, and biofouling of well screens and collectors. We applied BART biodetectors as a reliable tool in monitoring well rehabilitation effectiveness. This paper presents several process assessments based on BART biodetector tests conducted at Belgrade groundwater source.

Factors controlling of arsenic content in underground water are commented on the base of experimental obtained results of analysis of water quality from October to November 2006. The influence of water quality parameters and temperatures of water on examined locations of waterworks of middle Banat, south from Zrenjanin, public wells in Zrenjanin and waterworks north from Zrenjanin, on arsenic content is found.

Groundwater of Serbia is strategic natural resource which provides drinking water for about 75-80% of population. This resource is however not properly utilized and protected from pollution in accordance to its importance. Accepting to achieve the targets of EU Water Frame Directive, Serbia is in fact confirms the aim to better explore and protect the groundwater. The paper describes different activities planned under the project prepared in 2006 by the experts from leading Serbian institutions in water sector and in geology. Implementing this project until 2011 could create an ambience for future more sustainable exploitation and protection of the groundwater.