Assessment of Microbial Quality of Surface Water Sources of Luvuvhu River Catchment, South Africa

Abstract

The majority of global rural communities, including South Africa, rely on untreated surface water for human consumption. The consumption arises partly from the local municipalities’ erratic supply of treated drinking water to its residents. Here we report on the microbial load of surface water sources and after simple water treatment using hand dug wells in Vhembe District, South Africa. The results of the pH were in the range 6.90 to 8.86 with the water temperature ranging from 16 to 25 ºC. The turbidity values were in the range 2.53 to 393.67 NTU which shows problem of soil erosion, rainfall runoff and wastewater discharge by upstream sewage works. The faecal coliform counts varied between 0 cfu/100 ml to > 300 cfu/100 ml, E. coli counts varied between 0 cfu/100ml and >300 cfu/100 ml, and faecal Streptococci counts between 1.5 cfu/100 ml to >300 cfu/100 ml. The microbial load in the hand dug wells was considerably lower than that of the Nandoni reservoir (due to soil filtering capacity). The existence of a high microbial load that exceeded acceptable regulatory guidelines render these water sources unsafe for human consumption. Physical conditions, such as water temperature, also enable bacterial propagation. Thus, the advent of climate change and especially the warming of surface waters may exacerbate the current condition of the use of untreated surface water sources.