Microbiological, coliphages and physico-chemical assessments of the Umgeni River, South Africa

Abstract

The water quality of Umgeni River in KwaZulu-Natal (South Africa) was investigated from April 2011 to January 2012. Indicator bacterial populations, physico-chemical properties, heavy metal contaminants and the presence of coliphages were determined according to standard protocols. The results showed that all sampling points failed to comply with the set guidelines for turbidity, total coliform, faecal coliform and total heterotrophic counts. Salmonella spp., Shigella spp. and Vibrio cholerae were also detected in all the water samples. The somatic coliphages and F-RNA coliphages were detected more frequently in the lower reaches of the river during summer. Temperature, electrical conductivity and pH were found to have positive relationships with the microbial communities especially in the lower catchment area during spring and summer indicating the impacts of various anthropogenic activities in the surrounding areas.

uMngeni Basin Water Quality Trend Analysis for River Health and Treatability Fitness

“…The time-series plots in Figure 11 depict seasonal fluctuation and peaks of E. coli levels. The peaks that are pronounced in the wet season could be as a result of increased surface runoff from burst sewer pipes and slurry from intensive livestock farming operations that flow into the river course [64,65]. Storm wash-off containing accumulated human, animal and domestic waste material and overflowing pit-latrines also cause contamination during high flows [64,65].…”

“…The peaks that are pronounced in the wet season could be as a result of increased surface runoff from burst sewer pipes and slurry from intensive livestock farming operations that flow into the river course [64,65]. Storm wash-off containing accumulated human, animal and domestic waste material and overflowing pit-latrines also cause contamination during high flows [64,65]. The mean range of 97 to 1319 CFU/100 mL (Table 9) shows that water quality along uMngeni Basin is not fit for direct drinking purposes without disinfecting.…”

The evaluation of the health status of Clarias gariepinus from the Inanda and Nagle dams in KwaZulu-Natal, South Africa.

“…Possible drivers of NO2 in the Inanda Dam include effluent from municipality treatment plants and intensive agricultural activities. Singh and Lin (2015) recorded considerable NO2 concentrations in the uMgeni River ranging from 1.54 to 1.58 mg NO2/L during the winter and summer surveys.…”

“…The neutral and alkaline pH often show mesotrophic and eutrophic state of natural waters (Dirican 2015). The alkaline pH in the uMgeni River is often associated with microbial processes (Singh and Lin 2015). Ahipathy and Puttaiah (2006) highlighted that slight alkaline pH is preferable in waters because it removes metals as carbonate or bicarbonate precipitates.…”

“…The Department of Water Affairs and Forestry (DWAF) implemented target water quality range (TWQR) guidelines for all various water uses and processes (DWAF 1996;Cude 2001). Physico-chemical variations of river water may be influenced by climate, geology, soils and biotic regions in which they flow (Singh and Lin 2015). Water chemistry is further influenced by multiple natural and anthropogenic factors which are either spatially diffused or concentrated (Ahearn et al 2005).…”