Initially, all wastewater was treated in a single wastewater treatment plant and all the treated effluent was used for artificial recharge. In 1986, this practice was discontinued due to water quality considerations and separate treatment plants were constructed for domestic and industrial wastewater treatment. These came online in the mid-1990s. The domestic wastewater undergoes full secondary treatment with nitrification-denitrification steps (anaerobic-anoxic-aerobic). The effluent from the secondary settling tanks is polished in a series of maturation ponds. The maturation pond effluent is blended with the urban storm water run-off before discharge into the main recharge basins.
Source: Tredoux et al. (2009).
From collection: Sanitation and Wastewater Atlas of Africa - Ecosystems