The impact of wastewater treatment effluent on water resources: a South African perspective

Abstract

One of the major contributing factors to the many pollution challenges experienced in most parts of South Africa is the declining state of municipal and industrial wastewater and sewage treatment management. This contributes to environmental and human health problems. Globally, around 80 per cent of wastewater flows back into the environment either as untreated or partially treated, which poses risks to downstream ecosystems and people who rely on the river as a drinking water source.1 Discharge of untreated or partially treated wastewater effluent occurs mostly due to inadequate maintenance of wastewater treatment works, which results in equipment and infrastructure failure, producing poor quality effluent.2 The deterioration of the quality of a water resource has a significant impact on socio-economic development because such water cannot be used for bathing, drinking, industrial, or agricultural purposes. Rapid water depletion and pollution have led to the decline of available water resources for human consumption and the compromising of ecological integrity. Freshwater resources constitute only 3 per cent of all water on the planet, with 2 per cent being found in icecaps and glaciers which cannot be utilised, and less than 1 per cent readily available in rivers, dams, and lakes.3 Water is an essential component in the existence of every living organism; hence the protection of water resources is of utmost importance. Major contributors to water quality deterioration in South Africa’s water resources are agricultural runoff, extensive coal mining activities, and industrial activities combined with a general decline in the operation and management of wastewater treatment infrastructure, especially sewage treatment.4 Water resources of good quality are a precondition for economic development and ecological integrity.