Effect of agricultural and industrial developments on the quality of water at UMhlathuze River (Northern Coast of Kwa-Zulu Natal, RSA)

Abstract

UMhlathuze River is the main recipient of domestic, sewage, industrial and agricultural waste from local industrial and agricultural practices. Scarcity of water resources and the contamination of UMhlathuze River by agricultural and industrial developments make communities around UMhlathuze area susceptible to potential outbreaks of water-borne diseases as well as the risk of ingesting carcinogenic substances. In determination of the effect of human developments on the UMhlathuze River, four different sites representing different human activities were used for sampling along the river. Temperature and pH were monitored in situ using potable meters. Spectroquadrant Pharo 300 (Merck) was used for chemical analysis of water. Chemical oxygen demand (COD) was measured using spectrophotometric methods. Microorganisms were isolated and identified using standard biochemical methods. Temperature and pH were found to vary between 19 to 21 and 6.2 to 7.8°C, respectively. COD was found to be higher in areas affected by both industrial and agricultural activities. Agricultural waste recipient area had high concentration of phosphate, ammonia and nitrate. Parts of the river receiving effluent from treated wastewater had high sulphide, nitrate and ammonia concentrations. Industrial areas have a high concentration of heavy metals (for example Aluminium). Microorganisms found in all sites included Escherichia coli and species of Salmonella,Shigella, Citrobacter, Serratia and Enterobacter, although their numbers differed from agricultural to industrial sites. Agricultural and industrial development activities practiced along UMhlathuze River were found to have a huge contribution to the continued deterioration of the quality of water at UMhlathuze River. Key words: UMhlathuze River, water pollution, water quality, public health, agricultural and industrial developments.