The impact of industrial effluences on water quality in the Waterval River catchment

M.A.The goal of this study is to determine the water quality of the Klipspruit River over a six-year period, from 2000 to 2005. The Klipspruit lies within the sub-catchment area of the Waterval River, which in itself forms part of the Upper Vaal Catchment. The Klipspruit runs through the city of Secunda in Mpumalanga Province, South Africa, its catchment area providing two percent of the water to the Vaal Dam. In its turn, the Vaal Dam is the main raw water source for Rand Water that provides potable water to 10 million people in its 18 000 square kilometre service area. This study specifically focuses on the long-term trends of six selected water-quality parameters related to the effluent generated at the Sasol Secunda Industrial Complex (SSIC) during its coal-to-fuel operations. Certain physical, chemical and organic water-quality parameters of the Klipspruit were investigated on the basis of samples taken from three monitoring points in it. The water samples were analysed in terms of the water quality guidelines stipulated by the Department of Water Affairs and Forestry (DWAF), as well as the In-stream Water Quality Guidelines laid down by the Waterval River Catchment Management Agency. This was done to determine how industrial effluent impacts upon water quality in general and also how it affects water usage in other respects. The water-use categories considered in this study include aquatic ecosystems, domestic systems, livestock watering and irrigation systems. The results of conducting a regression analysis on the data collected from the monitoring points on the Klipspruit and assessing it in terms of the specifications laid down by the guidelines in question show that the respective concentrations of a number of water quality parameters in the upper part of the Klipspruit often exceed the ideal water quality levels. However, these concentration levels stabilize over time as the river continues to flow downstream. This is mainly due to the location of the first monitoring point which is close to the Sasol Secunda Industrial Complex (SSIC), where the effluent is generated, and also because the Secunda Sewage Treatment Plant is in the vicinity