The results of the first (since 1939) hydrochemical investigations of Gliwice Channel have been presented. The polluted K.lodnica River affects bad water quality of the canal. For example the concentrations of chlorides (Cl), sulfates (S04), sodium (Na), potassium (K), conductivity and dissolved substances quality of water is out of standards. In the case of BOD and COD the water quality is changed from out of classes to II class. pH and oxygen concentration are in I class. Although no salinity waters flow into the canal, the water quality get improved slightly only. The decrease of pollutants concentration is related to theirs dispersion. In the case of water quality the self-purification processes are of secondary importance.

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.