Abstract
Al – Baqaa sewage is treated by the activated- sludge process. 36 of the total number of bacteria entered in the raw sewage were removed. Pathogenic bacteria such as Salmonella typhi and Shigella dysentria were detected in raw sewage but not in the treated sewage effluent. Also, Saccharomyces cerevisiae was isolated from sewage samples and about 5 of the yeast number was still present in the treated effluent.