The basic purpose of Gruza accumulation is to supply the town of Kragujevac and its vinicity with drinking water. The accumulation occupies large area, comparing with its relatively shallow water and low water mass, which is essential for water eutrophication. The aim of this research is to determine water quality, through index of phosphatase activity at five locations in one year period. According to the results obtained for index of phosphatase activity, water of Gruza lake belongs to 3rd A category. The maximum obtained value (19.60 micromol/s/cubic dm) was determined in the shallow part, at mouth of the river Gruza in July, 2000, and the minimum one (0.39 micromol/s/cubic dm) in the deepest part of accumulation, at location Brana in March, 2001.

Heavy metals contamination of the muscular tussue of nase (Chondrostoma nasus), bream (Alburnus brama) and bleak (Alburnus alburnus) fish species from the Medjuvrsje water reservoir (the Zapadna Mora river), was examined. With the expection of the nase muscular tissue where cadmium (Cd) and mercury (Hg) concentrations above and slightly below MPC, respectively, were detected, the rest of the samples were safe. With the aim of conducting more thorough monitoring of these pollutants, a greater number of elements and a larger number of organisms should be included in the analyses.

The paper presents results of research on hydrophilic flora of the Grosnica reservoir in the Kragujevac basin (Serbia, Serbia&Montenegro). The obtained results confirm that the development of hydrophilic vegetation is dependent on the time, manner, and place of reservoir formation, as well as on the extent of human influence. Analysis of floristic composition of hydrophilic plants of this reservoir indicates presence of 30 species belonging to 20 families. Floristic composition of the hydrophilic flora with flora elements, life forms and ecological factors are presents.

In the period October 2001 through November 2002 in six series parallely with physico-chemical and hydrobiological analyses, the content of photosynthetic pigments was determined in algae in the region of flow-through reservoirs of "Djerdap 1" and "Djerdap 2" on the profiles of Smederevo, Ram, Veliko Gradista, Donji Milanovac, Tekija, Kladovo and Radujevac. The samples were taken by a pump from the river midstream at the depth of 1-0 m (composite sample), while in the vegetation period April, June and September, the samples were taken at the depth of 5 m. The peak concentration of chlorophyll-a, the biological indicator of trophic condition, was recorded in the month of April in the Smederevo profile (30.2 mg/cubic meter) at the depth of 1-0 m. The lowest values of chlorophyll-a in all studied cycles were recorded in the Radujevac profile (below the dams) with the mean annual value of 1.8 mg/cubic meter. Chlorophyll-c occurs as the subdominant photosynthetic pigment. Values of chlorophyll-c were higher than chlorophyll-a in the month of June on the Donji Milanovac profile in the analysed sample taken at the depth of 5 m. Higher values of chlorophyll-b were recorded in the course of the vegetation period in the month of June on the profiles of Smederevo, Ram, Veliko Gradiste and Donji Milanovac at the depth of 1-0 m.

The lack of drinking water in Zajecar was the main reason for building of water barrier on the Grliste river and making the water reservoir. A factory for water processing was also built, but the problems were not disappeared. The conclusion is that the main solution for this ecosystem was in establishing of an monitoring system. That is the reason why we talk out the results of the monitoring and the troubles in this water source as well as in the phases of water processing.

There have been given research results of quantitative and qualitative indices of communal and industrial waste waters of Nis. The research was carried out by the Institute "Jaroslav Cerni" (group of authors) and JKP "Naissus" (4) with the goal of defining as reliable parameters as possible in order to draw up plans for a central wastewater cleansing plant in Nis, as well as several necessary treatments of the industrial waste waters. There have been presented quantities, load and expected load of the total waste water, basic characteristics of urban and natural recipient, waste water influence on the river Nisava and needed degree of cleansing.

The paper gives the contribute to analyses of the problem of Crnojevica river (Montenegro, Serbia&Montenegro) water pollution. The analyze surround measurement the next parameters: pH, conductivity, oxygen balance, sanitary parameters, content of different form of phosphorus. These measurements are carried out over five sampling series, at the seven stations, including underground flow rate in the Obod cave. Our estimations are confirmed the continuity of the Crnojevica river pollution, by municipality and strain water from Cetinje urban area. Nutrients, especially phosphates, from the pollution emission, attend conditions (together with many natural factors) for production biomass quantity. The opposite processes, the inhibition processes, exist. Phosphorus in the water attends increase level of the water pollution (over increase eutrophication degree), so the water is out of the legal class, because its usage is limited.

This paper presents longtime (1986-2001) researches waste waters quality from "Djuka Dinic" tanery, Nis (Serbia, Serbia&Montenegro), as well as their influence to recipients (municipal sewers and the Nisava river).Needed grades of purification of relevant pollutants to recipient are defined as well as schematic possible solutions for waste water purification. The most optimal solution for purification of waste water from tanery from "Djuka Dinic", Nis, is common leading of waste waters to municipal sewers (waste waters from factory 2 for pig leather treatment enter now to the Nisava river without purification) with adequate pretreatment. Based to recently experiences as well as laboratory researches pretreatment consist of: rudely dispersed material removal (grates and sieves), equalization, primary sedimentation and coagulation with flocculation and sedimentation gives good results. Meanwhile, technological purification scheme that include separation flot from leaching and tannering from common flow of collective waste waters and their special treatment, respectively repeated use, has significantly adventages: pollution decreasing of collective waste water, saving of basic reagents that use as raw materials in treatment leather in recuperation or repeated use, eliminating waste sludge with chromium and economize of purification process.

Water quality examination of water source Zagoric, was conducted with aim to determine water quality on the bases of physico-chemical parameters, in dry and rainy period. Water supply system in Podgorica scopes several water supply sources out of which Mareza and Zagoric have the greatest capacity. The aim of this study was to determine hygienic quality of water in operational and dug wells on representative locations in flow areas, and on the basis of obtained results to estimate its influence on population health.

The results of the regular water quality monitoring in the river Moraca (Montenegro, Serbia&Montenegro), are presented in this paper. Thirty samples have been processed from six measuring station along the river's flow. The data relevant quality indicators (conductivity, dissolved oxygen, chemical oxygen demand, five days biochemical oxygen demand, ammonia, nitrites, nitrates, and phosphates) have been processed in the light of the existing regulations. It has been confirmed that the water quality, from the physical-chemical aspect, varies depending on the measuring location and the hydrological situation. The evaluated condition shows that the water quality gets worse, in the period of the five years, on the profiles of downstream places from Podgorica. The level of decrease gets to deviation from the requested A2CII class. It is particularly shown in the changes of the values for the nutrients and the relevant indicators of the organic pollution (dissolved oxygen, five days biochemical oxygen demand, chemical oxygen demand), which we presume can be consequence of the effect of the algaes during the period of the "low level water".