The influence of two large farms of fur-bearing animals, used for 37 and 35 years, respectively, was assessed with respect to the contamination of surface and underground waters. Some physico-chemical and bacteriological properties of well water, tap water and of the river water situated near those farms were tested. Organoleptic indices were normal, but the concentration of NH₃ in the wells of the two farms (7,68 mg and 7,0 mg per 1 dm³, respectively) was much higher than normal (0,5 mg per 1 dm³). The level of nitrates was also significantly higher, i,e. 11,67 mg and 20 mg per 1 dm³ in the well of the farm S and in the pond of the farm B, respectively. Both surface and underground waters in the area of the two farms contained great amounts of organic substances and hence a much higher level of bacteria than standards permit.
The examinations were carried out on two farms containing altogether 25 000 foxes. Ninety different samples, i.e. 14 feed samples, 16 collective excrement samples and 60 soil samples were examined bacteriologically. Lack of microorganism growth was confirmed in only four soil samples. From the remaining samples bacteria classified to Proteus, Escherichia and Salmonella species were isolated. Salmonella species were found in 29 samples (S. dub- lin - 7 strains, S. enteritidis - 10 strains, S. typhimurium - 12 strains), i.e. seven in feed samples, six in excrement and sixteen in soil samples. Salmonella strains presence in soil material, including the samples from a protected region, points to the bacteria dissemination from animal farms to the natural environment.