The sanitary condition of the water in the Brda river

The paper presents the results of the research on the number of heterotrophic bacteria developing at 22°C (TVC 22°C) and 37°C (TVC 37°C) and on the number of bacteria which serve as indicators of sanitary quality of water (incl. total coliforms (TC), faecal coliforms (FC), faecal streptococci (FS) and Clostridium perfringens) in the upper Brda river. (i.e. from its spring to the village of M cika ). The figures reveal that psychrophilic bacteria (TVC 22°C) constituted the most numerous group in the examined part of the Brda river. The highest counts of mesophilic (TVC 37°C) and psychrophilic bacteria (TVC 22°C) were detected in autumn/spring and in spring/summer months respectively whereas their numbers dropped sharply in winter-time. Both groups developed most extensively at Site II (the village of Nowa Brda) while their lowest numbers were identified at Site IV (M cika ). Of all the indicatory organisms used for the evaluation of the sanitary quality of the Brda river total coliforms (TC) made the most numerous group, while the numbers of faecal coliforms (FC) and faecal streptococci (FS) were slightly lower. Bacteria Clostridium perfringens which reduce sulphites were not detected. The maximum numbers of the indicatory bacteria were noted at Site III (before Lake Charzykowskie), the minimum - at Site I (the spring of the Brda river) and Site IV (M cika ).