Improving the efficiency and sustainability of disinfection at a small rural water treatment plant

Abstract

The Alice Water Treatment Plant (AWTP) has several operating problems, which often result in poor turbidity removal and inadequate disinfection residual. Some progress has been made in upgrading the skills of plant operators, but the plant performance has failed to improve because of faulty equipment, a shortage of maintenance staff and treatment chemicals that are not delivered in time. The coagulant-dosing pump was found to be malfunctioning for an extended period of time resulting in overdose problems. The self-backwashing filters were no longer backwashing as per design and were producing poor quality filtrate. This in turn increased the chlorine demand and combined with frequent failure of the chlorinators, the plant was producing poor microbiological quality final water. The storage system in the bulk distribution system was investigated and it was found that adequate chlorine residual could be achieved, provided the plant problems were rectified. The difficulties experienced in training and retaining adequately skilled people to run water treatment plants in impoverished rural municipalities have been among the major hurdles to providing acceptable water services in these areas. However a partnership between the Universities and the AWTP came up as a possible solution to these problems. It is therefore recommended that rural municipalities consider this approach and strengthen this relationship, as it played a large role in plant improvement. Water SA Vol. 30 (5) 2005: pp.69-74