Water Quality Of The Fonteinspruit Stream On The Outskirts Of Bloemfontein, Free State, South Africa

Abstract

Introduction: The quality of water was measured in water samples collected at the 12 water sampling sites in the Fonteinspruit stream. The Fonteinspruit stream extends about 4.5 km in length and drains an area of about 17 km2, wherein high-density residential areas, a Water Treatment Plant, industrial and agricultural areas as well as an informal settlement, are located. The contamination of the Fonteinspruit stream is attributed to human-induced activities such as improper disposal of solid waste and domestic sewage, animal manure and industrial effluent, which contain pollutants and other emerging contaminants. The contamination of this stream poses health risks to humans, animals and aquatic organisms. Methodology: In this study, water quality was assessed in water samples collected in the Fonteinspruit stream in terms of conventional physical, chemical and microbiological properties as well as the presence of emerging contaminants, namely carbamazepine, estrone, estradiol, 17a ethynylestradiol, bisphenol A, atrazine, metolachlor and terbuthylazine. The ecological quality of the stream was also assessed by enumerating aquatic macroinvertebrate families from which the quality of their habitats could be evaluated. A Water Quality Index was calculated for the water at each water sampling site to ascertain the overall water quality at a particular water sampling site and thereby obtain an understanding of the water quality in the Fonteinspruit stream. The South African Scoring System 5 was employed to measure the biological effects of polluted water on aquatic macroinvertebrate families. The health conditions of the water at each sampling site were classified in terms of the modelled reference conditions for the Highveld Ecoregion. Results and Discussion: The water quality of the Fonteinspruit stream was found to be poor due to high levels of turbidity, electrical conductivity and phosphate and high bacterial counts of coliforms and Escherichia. coli. The compliance rate was below 20% for many of the measurements, particularly for turbidity, phosphate and total number of coliform bacteria as well as the emerging contaminants, such as carbamazepine, estrone, estradiol, 17a ethynylestradiol, bisphenol A, atrazine, metolachlor and terbuthylazine. The presence of only pollution tolerant aquatic macroinvertebrate families strongly supported the notion that ecological conditions of the water at all 12 water sampling sites in the Fonteinspruit stream were critically impaired. Conclusion: In conclusion, water quality of the Fonteinspruit stream was deteriorating; that human-induced activities were affecting the water quality in the stream; that the poor water quality in the Fonteinspruit stream was affecting the aquatic macroinvertebrates and their diversity. Finally, human and animal health could be at risk if they accidentally drink the contaminated water in the Fonteinspruit stream during swimming or if they eat vegetables irrigated with the contaminated water.