Results of the study presented in this article and earlier have been the first ones since the Gliwice Canal was put into service in 1939. Until now there have been no investigations concernig (the Canal state in the area of hydro-chemical study), sanitary state or level of sediment contamination. The aim of this study was therefore to obtain information about the current pollution. The level of aquatic environment in some reaches of Gliwice Channel. This article presents the results of investigations carried out in order to assess of water quality in the Canal relating to nitrogen and phosphorus compounds. The following nutrients were determined in water samples ammonia, nitrite and nitrate nitrogen as well as organic dissolved and organic suspended nitrogen. In addition concentrations of orthophosphates, polyphosphates and organic phosphorus were analyzed. The analyses were carried out in water samples taken in six samplings from January till June 2000. Water samples were drawn at 7 sampling points. Samples of bottom sediments were taken at 21 sample points. Basing on the results of analyses the water quality of Gliwice Canal has been determined. A classification of chemical parameters was carried out under the provision in force. Basing on this classification we can state that water in the Canal is does not quality for any class system. We can also affirm that the water quality on the whole length of Gliwice Canal has improved only slightly even though waters of lower pollution levels supply the Canal.

From March to October 1998 carried out hydrochemical and hydrobiological researches on retentional water reservoir Przeczyce on the Czarna Przemsza river were. Surface area of this reservoir is 570 ha. Maximal depth is 10 m, total volume 20 mln m3• In results self-purification processes water in the ecosystem is in I and II quality class. In the saprobity clasassification it is in betamezosaprobic class. Low number of macrobenthos organisms is the result of the Czarna Przemsza river pollution. In the I Part of this paper results of hydrochemical investigation was given.

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.

There is a need for quality control of wastewater introduced into drainage systems. Physical and chemical analyses of wastewater inform only about the situation existing at the moment of sampling. The analysis based on bioindication methods allows to evaluate the existing state before sampling and so to recognize a drop of excessive loads or harmful substances for activated sludge. This refers to the moment preceding the sample taking at least by the generation time of the species with the lowest reproduction rate. For these reasons, the possibility of using microfauna representatives (feeding on organic pollutions) for bioindication was evaluated. The estimation was made of the usefulness of indicator species from the Kolkwitz-Marssori system, the Shannon-Wiener index based on species abundance and the latter based on abundances of morphological-functional organism groups. The study results showed that the ShannonWiener index calculated for morphological-functional groups (easiest to determine) was accurate enough for bioindication.