Abstract
M.Ing.
Rietvlei Dam was completed in 1933, and has been utilized as a drinking water source for the City of Pretoria since then. The original process configuration operated for almost 50 years before being upgraded in 1988. This upgrading was mainly due to the eutrophication of the impoundment. The new plant worked excellently under normal conditions but certain serious problems did occur and full production could not be maintained at all times. Activated Carbon and Ozone are two possible solutions to these problems. This study was directed at investigating the possible implementation of Preozonation, Granular Activated Carbon, and Ozone and Granular Activated Carbon in combination (case study), and it was shown that: All these processes are beneficial to the final water quality. Pre-ozonation proved to be the most cost effective process, but the least effective process in improvement of the water quality. Ozone and Granular Activated Carbon in combination proved to be the least cost effective process, but should be the most effective in improvement of the water quality. Granular Activated Carbon proved to be the optimun process with regard to cost and water quality improvement. The final recommendation is the implementation of Granular Activated Carbon with an empty bed contact time of 10 minutes.