Minimizing risks in wastewater reuse: proposed operational principles and guidelines for South Africa

Treated wastewater represents a significant potential source of reclaimed water for some beneficial reuses. However, public concern over the risks/health-related hazards of wastewater reuse has limited the general acceptability of reuse systems in many countries. It is important to manage the operation of recycled water systems in such a way that it will not adversely affect public health and the environment. Management of recycled water involves process control and compliance monitoring. This paper presents proposed unit process monitoring guidelines to classify the performances of treatment units according to the pollutant removal efficiencies and frequency of sampling to test for effluent quality suitable for reuse. The paper also highlights the procedure for proper inspection of treatment facilities to ensure optimum performances. It proposes minimum quality requirements for different reuse activities in South Africa such as domestic (toilet flushing, watering private gardens), irrigation (crops, landscape, public parks and golf courses, cemeteries), industrial (system cooling and process water) and other activities (construction works, street cleaning, fire protection, groundwater recharge). By employing the wastewater treatment monitoring and sampling procedures proposed in this paper, health-related hazards can be minimized while public confidence in reuse schemes will be enhanced.