An Assessment Of The Impact Wastewater Pollution Has On The Quality Of Surface Water Bodies In The Vicinity Of Zastron And Matlakeng Township, Free State Province

Abstract

Introduction: A breakdown in wastewater infrastructural systems have, in recent times, resulted in extensive pollution of rivers, dams and streams in the vicinity of Zastron and Matlakeng Township. The consequence of extensive pollution of these surface water bodies has resulted in the degradation of the water quality and the health of the ecosystem. Polluted water may become a source for transmitting waterborne diseases, which is a cause for concern, especially when the water is used to irrigate agricultural produce. An assessment of the surface water quality of water bodies in the Zastron and Matlakeng Township provided information about the extent of the deterioration and degradation of the water quality of the surface water bodies. Methodology: In this study, an assessment of the municipal complaints registers of the Mohokare Local Municipality was conducted to identify suitable sampling sites in the rivers, dams and streams that were directly impacted by untreated sewerage flowing from blocked manholes or sewerage leakages from pipe bursts overflowing in the Matlakeng Township. From this analysis, ten surface water bodies were identified to most likely be affected by wastewater pollution as a result of the infrastructural breakdown in the vicinity. To assess the water quality of the 10 sampling sites, the physical, chemical and microbiological water quality properties of the sampling sites were measured over three sampling rounds. To determine the ecological health status of the macroinvertebrate sampling site habitats, an ecological assessment for the 10 sampling sites was also conducted. A number of indexes were used to determine the water quality status for each of the sampling sites. These included the calculation of a Water Quality Index (WQI), the South African Scoring System (SASS), and the Average Score per Taxa (ASPT). Results and discussion: The study found that on assessment of community infrastructure related complaints lodged with the municipality were mostly as a result of and poor workmanship with the construction of sewer networks. This resulted in blocked manholes and sewerage leakages that which caused sewerage overflowing from manholes and burst pipes. The infrastructural breakdowns had resulted in the discharge of untreated wastewater into surface water bodies located within close proximity to where most challenges were identified from community complaints. The assessment of the physical, chemical and microbiological water quality had revealed non-compliant Turbidity, Ammonia and Phosphates parameters, while the microbiological water quality had declined extensively after the first sampling round. Turbidity and elevated concentrations of Ammonia and Phosphates, as well as the high counts of faecal coliforms could be attributed to wastewater pollution. The calculation of the CCME WQI classified all the sampling sites as poor. Sampling site H and site D were the only two sampling sites classified as marginal. The two sites are located furthest from wastewater pollution and thus, the classification. The ecological assessment revealed that all the surface water bodies were classified as critically impaired. Sampling sites classified as critically impaired are sites where only a few pollution tolerant macroinvertebrates survive. Most of the sensitive aquatic organisms have died because of the wastewater pollution from the breakdown in wastewater infrastructural systems. Conclusion: It can be concluded that the surface water bodies in the vicinity of the Zastron and Matlakeng Township was polluted by wastewater that had flown into it from either blocked or overflowing manholes and malfunctioning pump stations. It is recommended that infrastructural needs in the areas identified, as those mostly affected by infrastructural challenges should receive attention by the responsible local authority in order to prevent any further wastewater pollution of the surface water bodies. Such an intervention can result in the improvement and the restoration of the surface water body quality over time.