The analysis of water self-purification process includes headstreams of rivers in the Upper Silesian agglomeration: the Bierawka, the Kłodnica, Bielszowicki creek and the Szotkówka. These are rivers characterized by small natural flows and a significant anthropogenic pol I utant load. Results of our own research on the self-purification rate were used. The attention was focused on biodegradable substances. The biodegradation rate coefficient k, and water assimilative capacity were determined. Within the same rivers, their particular parts differ in types of a riverbed and swift currents alternate with slow flows. In the case of Bielszowicki creek and the Szotkówka River impoundments were observed, which results in different self-purification conditions. In all investigated parts the rate of organic substance removal, characterized byk, coefficients, was usually much higher than the literature values for comparable rivers, which usually are below 2.0, rarely exceeding 3.0. The creek impoundments occurring in the watercourse beds do not always have a positive impact on the water quality. The role of the creek impoundments in the river self-purification process and their impact on water ecosystems require separate investigations.

For majority of running waters point pollution sources are the main sources of pollution. Knowing the water self-purification capacity one can modify the quality of waters through proper management of the discharged pollutants. This study focuses on identifying such solutions for pollutant discharge into the Kłodnica and Bytomka rivers, which would allow for achieving at least the Ill class of surface water quality. Simulation of selected wastewater management scenarios was carried out. The best solutions for the water environment were identified. Only environmental effects which resulted in improvement of the water quality were analyzed. The economical aspect of actions, the undertaking ofwhich is indispensable for achieving the assumed goal, was not taken into account. The selection of the best solutions considering the cost effectiveness cannot be made until a feasibility study for particular undertakings has been completed. Sal i nity and biodegradable pollutants determined by BOD coefficient were taken into consideration. The simulation was carried out using an integrated simulation model IRM (Integrated River Model). In order to protect the river from excessive salinity the optimum solution for the Bytomka River would be desalination, whereas for the Kłodnica River- directing salty mining waters outside its catchment. For protection from biodegradable pollutants the only solution would be tightening the effectiveness criteria for municipal wastewater treatment. Meeting the minimum standards for wastewater treatment, currently obligatory in municipal wastewater treatment plants, will not ensure the assumed water purity level in these rivers.

The paper presents the way of water quality improvement in storage reservoirs, using pre-dams with plant filters. Pre-dams, built above the main reservoirs, reduce the inflow of pollutants transported by the river and take over most of biochemical processes responsible for eutrophication of the stored water. As a result, water flowing to the main reservoir contains smaller loads of pollutants. The above-mentioned method is more economic, requires relatively short construction time and is less laborious than generally used methods of surface water protection. It is specially recommended to improve the quality of water in small reservoirs, where quick silting and eutrophication occur. Proper functioning of pre-dams depends on proper selection of their parameters, such as: water storage time, water flow velocity, filling depth and type of plant filters. The authors estimated the effectiveness of a pre-dam reservoir situated above the main reservoir in Mściwojów on the Wierzbiak River. The pre-dam reservoir consists of a three-chamber sediment tank and three chambers with plant barriers. The purpose of the chambers is to decrease the quantity of sediments, the biogenie substances and other pollutants carried with water flowing to the main reservoir. Research carried out during the period 2000-2001 showed that pre-dams significantly contributed to the improvement of the water quality in the main reservoir - nitrates were eliminated in ca 65% and phosphates in ca 52%.

The aim of this study was to assess soil contamination with toxic metals in the area of Piekary Śląskie (Silesian Voivodeship), taking into consideration various land use patterns. The scope of research covered the determination of lead and cadmium concentration in soil in the following areas: allotment gardens, fallow lands and kindergarten playgrounds. The lead and cadmium concentrations in soil samples were determined using a flame atomic absorption spectrometry technique, after the aqua regia extraction in a MDS 2000 microwave digestion system. The metal contents in the analyzed soil samples varied remarkably, depending on the sampling location and its distance from the main emitter of toxic metals in Piekary Śląskie, i.e. "Orzel Bialy" Non-Ferrous Metal Smelter. Metal concentrations determined in all soil samples significantly exceeded the concentration levels accepted in Poland for arable lands and residential areas. The lead and cadmium concentrations in soil should become the basis for stopping edible plants cultivation in the area of Piekary Śląskie. The contaminated soil in kindergarten playgrounds can be an important source of lead and cadmium contamination, posing hazard to the children's health. Contamination of playgrounds with toxic metals should stimulate undertaking actions aimed at modernization of playgrounds and reduction of the children's contact with soil. In the context of the applied result assessment criteria the soil concentrations of these metals observed in the region of Piekary Śląskie should arouse great concern among its users and local authorities.