According to the plans, the town of Gacko tends to be water supplied from the water reservoir Vrba located at the river Vrba. About 150 to 200 m away is located ash basin. All ash basin area is oriented to the water reservoir and leaking water going directly to the water reservoir. The leaking water has high pH value, alkalinity, high content of sodium, potassium and sulphates. There are some heavy metals, but their concentrations are not significant. The influence of those contaminated water on the lake water quality is only little evident because of the high dilution rate.

The most extended and deepest belt of macrophytic vegetation, the belt which almost without exceptions define the lower limit of littoral region of Lake Ohrid, consists algae from the family Characeae. Permanent presence of sunlight, well oxygen saturation, their density which decreases the waves action, together with the facts that these algae are food and shelter for the numerous endemorelic species from the very rich fauna of macro invertebrates, make the stonworts the most attractive life habitat in Lake Ohrid. Our results are found on researching of three types facies from four different localities in Lake Ohrid: sandy-muddy facies without of stoneworts, facies covered by stoneworts and facies covered by Gastropod and Bivalvia shells, also without of stoneworts. Without exceptions, in all four localities we approved the mentioned affirmation about the great importance of the stoneworms as life habitats, both by the number of present taxa and the density of the macro invertebrate communities.

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.

The results of a study on the water of the Sumanka river during several years point out the decrease in its quality. The results of the present study show that the technological actions, as well as the some technical changes, carried out in the Lebane's plant in Grgurovci gave the satisfactory effects. Turbidity, colour, KMnO4 demand and ammonia are efficiently reduced, along with low concentrations of Fe, Mn, and residual Al, ensure completely the water standard quality in accordance with the Protocol.

Bacteriological examination have been carried out within the comprehensive hydrochemical and hydrobiological investigation of river Koselska during 2002. The aim of investigations is to confirm condition of bacteriological communities and water quality of river Koselska. The results of investigations shows pollution by organic matter. In order to prevent further eutrophication processes, certain measures of river water protection and conservation should be undertaken. Also, the regular monitoring of water quality should be established.

The paper deals with pilot-scale investigations of the effect of preozonation on NOM removal from groundwater by coagulation and flocculation processes. It was found that the preozonation increased the efficiency of organic matter removal by coagulation and flocculation from 23.6 to 47.2% as judged on the basis of KMnO4 values. From the aspect of the change of content of trihalomethanes precursors preozonation exhibits both the positive and negative effects if their content in the water after coagulation is considered in dependence of the applied ozone dose. The obtained values siggest the necessity of careful optimization of the processes of preozonation, coagulation, and flocculation, especially from the aspect of the change in content of the precursors of disinfection byproducts.

Sasko Lake, with surface area of 3.4 square km and depth of about 8 m, is situated is southwestern part of Montenegro (Serbia&Montenegro), within the hydrosystem of Skadarsko Lake. During 2002 and 2003, seasonal dynamics of main hydrographic, physical, chemical and biological parameters of this ecosystem was monitored. Reference measuring spots are defined, and in these places all future monitoring of system state will be accomplished. Also done are the preliminary batimetric measurements and maps of spaces suitable for development of breeding activities. In order to develop aquaculture as a strategic interest of Montenegro (Serbia&Montenegro), it is necessary to utilize these important potentials and place this important natural resource in full fuction. Included are the list of all fish species living in the lake, as well as the suggestion of species that could be suitable for commercial breeding.

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.

This work presents a short review of the existing situation, nature conditions and recognised facts which are important for the sea- pollution of the oil, and another kind of the spill ship oils, inside of the Boka Bay and in the area of the open Adriatic Sea. The proposed original and innovative action concerns the large scale application of a new technique for a cleaning up waterborne oil spills, based on the magnetic separation method by using the material "CleanMag", an oleophillic, and porous material which also is magnetic with an increased density lower than that of the water.

Degradation of groundwater quality whish is used as a raw water source, caused by the continuous pollution, develops gradually. Therefore, it is necessary to analyze the pollution influence, on the first place by the expect concentration of hazardous substances in groundwater. Water source protection measures are based on the results of these analyses.