The paper presents aquatic macroinvertebrate community composition at six investigated localities of the Veliki Rzav river (Serbia). Sampling were carried out during 2005. Characteristics of the macroinvertebrate community with field data were used to estimate the status of the river.

Water quality monitoring of surface waters encompasses the watercourses of the river basins of Una, Vrbas, Bosna, Drina, Ukrina and the direct Sava basin. Apart from comprehensive analyses which demand determinations of physical - chemical characteristics, as well as the ihtiofauna composition, special emphasis is given to the analysis of the macrozoobenthos. As a part of all water ecosystems, benthic invertebrate serve as a reliable indicator of the quality and changes of the environment, due to a series of advantages in relation to other communities. Most of the aquatic habitats, especially flowing waters of good quality of water and benthic state, enable various of benthic invertebrates communities with moderate formation of species within the overall number of the present individual species. This kind of communities react to possible changes in the community composition (abundance and macroinvertebrata composition).

The results of sediment quality monitoring gathered during the period 2002-2008 were processed and shown in the current work to assess the overall sediment quality in Vojvodina watercourses regarding heavy metals content. Since Serbia does not have legislation for sediment quality, Canadian and Dutch sediment criteria were used for evaluation of sediment quality. The elevated concentrations of heavy metals in Vojvodina watercourses are a consequence of the discharge of untreated or partially treated industrial and municipal wastewaters, but also of the corosion of metal structures and constructions (Cu, Zn) as well as the influence of difussion sources, principally agriculture (Cd, Cr, Hg) and transport (Pb).

The allochthonous aquatic macroinvertebrates and fish species represent a potential danger to the autochthonous diversity. Hydrobiological research conducted during 2008 under the development of medium-term programmes for fishery improvement in Serbia, showed that some of the allochthonous aquatic macroinvertebrates and fish species have expanded their areals to a new water habitats. Artificial lakes (reservoirs) proved to be very suitable for the population of allochthonous species, where they become numerous most of the time. New habitats were found for allochthonous aquatic macroinvertebrates species: shells (Dreissena polymorpha, Sinanodonta woodiana) and American crab (Orconectes limosus), and for fish species for Micropterus salmoides. It was also determined that fish populating is a good way to inhabit and expand new habitats with allochthonous species of aquatic organisms.

The Bovan reservoir is built on the river Moravica, near Aleksinac (Serbia), primarily for the purpose of water supply. Investigations were carried out during the period of June 2005 to December 2006, with the aim to determine the quality of water, the composition, spatial and time dynamics of communities of microorganisms. The results showed that according to the total number of bacteria in the water reservoir Bovan fall into the category of clean water by Amrazena (1976). By Kohl (1975), water reservoir Bovan belongs to class 2. Summer-time give maximum water characteristics the 2nd-3rd class. Index T/H varies from category to category moderately contaminated clean water. Values heterotrophs percentage representation in the total number of bacteria indicating the great burden of water organic matter.

Hospital effluents can be especially hazardous and toxic due to their content of chemical, pathogenic and bio-hazardous wastes. Many of these toxic pollutants are not fully removed or neutralized by traditional municipal wastewater treatment plants, which are primarily designed to address parameters such as Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), etc. They are also not easily removed by filtration, settling or flocculation. The common disposal of liquid waste from hospitals into the municipal network collection system or in cesspits is of serious concern and it requires swift and effective address. Wastewater from hospitals contains pollutants that are hazardous and require on-site management to prevent contaminating the city's sewage system and other surface waters. Unlike industrial operations that typically have a few large volume waste streams; hospitals generate different volumes of a wide variety of wastes and emissions. Most important chemicals in hospital wastewater are disinfectants (due to their major use in hospital practice), antibiotics, cytostatic agents, anesthetics, heavy metals (silver, chromium, zinc, lead, copper, platinum, and mercury), rare earth elements (gadolinium, indium, and osmium) and iodinated X-ray contrast media. Pollution prevention strategies and Best Management Practices (BMPs) to pollutant load reduction at the source is the best solution available to overcome this problem. The pollutant load reduction can be initiated by applying pollution prevention strategies and Best Management Practices (BMPs) to practices that use these chemicals. The goal of pollution prevention in healthcare environments is the same as throughout industry do to eliminate and/or reduce pollution at the source. The major difference when undertaking pollution prevention at healthcare facilities is that they do not manufacture a 'product', operate a fabrication 'process' or generate waste materials that can be readily recycled, reused or reprocessed. Therefore, the role of Pollution Prevention Strategies, Best Management Practices and Cleaner Production will be somewhat different than other industrial sectors. Pollution Prevention Strategies, Best Management Practices and Cleaner Production applicable to hospital wastewater management in Sri Lanka and Bangladesh are addressed in this paper.