Creation of scientific basis for rational use of water resources is impossible without studying viability of the microorganisms, their influence on the formation of chemical properties of natural waters and an explanation of the principles of biochemical processes such as transformation of elements in the aquatic environment. The survey of microbial (bacterial) characteristics of watercourses in the Republic of Srpska was conducted on a total of 64 streams within Operational, International and National surveillance monitoring. Sampling and analysis of samples was performed during the period from May to October. The study included ecological and sanitary aspects of river quality.

In order to collect information about the presence of priority and other substances whose quality standards are defined by Directive 2008/105/EC, the water and sediment quality monitoring was carried out in 6 sampling locations in four rivers and 14 sampling locations in protected areas in AP Vojvodina. The waters of the Carska Wetland, Ludas Lake and Danube River exceeded the quality standards for pentachlorobenzene, while the quality standard for cadmium was only exceeded in Carska Wetland. The priority substances detected in the sediment were lead, nickel, mercury, trifluralin, isomers of hexachlorocyclohexane (HCH), pentachlorobenzene, hexachlorobenzene, 4-octylphenol, naphthalene, anthracene, fluoranthene, benzo(b)-and benzo(k)-flouranthene, benzo(g,h,i)-perylene and indeno(1,2,3-cd)pyrene.

Water bodies like rivers and lakes are directly affected by the waste water in sewerage systems. Sewage systems provide waste collection and convey wastewater from the population in sanitary safely way and away from material property. DPSIR analytical framework allows the analysis of interactions between sewerage systems and water bodies. Sewer systems describe the different standards that are elements of their functioning including plants and their maintenance, hydrological, hydraulic and other influences. This paper gives analytical framework of Driver, Pressure, State, Impact, Response (DPSIR) in relation to the functioning of the elements considered sewage systems which are described in the Serbian (European) standard - SRPS EN 752 - 2:2007.

The stable isotope content of hydrogen (2H/1H), carbon (13C/12C), nitrogen (15N/14N), and oxygen (18O/16O) in surface water (the Sava river and channels) and groundwater (Ranney wells) were determined in Belgrade (Serbia) during July 2008. Detailed evaporation calculation has estimated that fraction of water loss to be between 10 and 20% in the channels using the local meteoric water line and the local evaporation line. Carbon-13 content in dissolved inorganic carbon is distinguished between surface water and groundwater indicating different evolution pathways of carbon. Based on carbon and nitrogen isotopic composition and C/N ratios, sources of inorganic carbon and of organic matter in analyzed waters are discussed.

This work shows the effects of opening the Itebej sluice gate on the metals content of the water and sediment of the Begej canal. A deterioration in water quality resulted, in particular on the first day after opening of the sluice gate, when high concentrations of Zn, Cr, Cu and Pb were detected. The metals content of the surface sediments across the canal at Klek had significantly higher concentrations of Pb, Cr, Zn, Cu and Hg five days after the opening, whereas there were no obvious changes at Itebej. From the metals content of the suspended sediment it can be concluded that the increase in metals contents occurred one day after opening the sluice gate.

Paper provides an overview of proposed methodology for planning and designing of system for collection, transport and treatment of road surface runoff in R. of Serbia. Methodology has objective to clearly define minimal scope and contents of required analyses, as well as to introduce into practice measures for protection of groundwater and soil from pollution, depending on sensitivity of the area on which road route is planned. paper also provides summary of required data and investigations needed for proper planning and designing.

The paper presents the results of orthophosphate concentration trends in waterflows in Serbia, using the method of non-parametric Mann-Kendal test. Data used for these purposes were provided by Republic Hydrometeorological Service of Serbia (RHMZ), sampled on average once a month for the period 1998-2007. Measuring places are shown on the waterflow map by adequate symbol for the various kind of trend and colour of symbol for the intensity of orthophosphate concentration. Statistical analysis of trends is discussed within the comparative review of methods of linear regression and Mann-Kendall test.

The aim of this paper is to present the use data of aquatic macro-invertebrates community, beside abiotic parameters, to define typology and type of specific reference conditions and index of ecological status, to contribute to the establishment of the system of ecological status/potential of surface waters in Serbia. The investigation involves macroinvertebrates as biological elements that have been widely used in implementation of the Water Framework Directive.

The aim of this paper is to present the current distribution of the species Corbicula fluminea and Corbicula fluminalis with new findings in Serbia. During the investigation performed from 1998-2008, these taxa were detected at 19 localities. It is noted that C. fluminea is well adapted to particular aquatic ecosystems, whereas C. fluminalis seems to be rare in Serbian waters. Wide distribution of alien clams, according to our results, showed that heavily modified main water ways are suitable recipient areas for introduction and adaptation of allochthonous organisms.

The puddles Novo Ilje 1 and Novo Ilje 2 are aquatic ecosystems periodically filled with moderate salt and alkaline water. In 2003 and 2004 quantitative analysis show the Euglenophyta domination. Trachelomonas taxa are the most common. The algae in planktonic communities are the most numerous in both puddles in researched years.