Abstract
This study evaluates the sanitary conditions of ten selected roof water tanks in Alkharj Governorate, KSA and examines their water quality. A survey was conducted using a questionnaire to collect information about the sanitation of these tanks. The physical, chemical and biological parameters of 60 water samples were examined using standard methods. The survey results revealed that 40% of tanks received unsatisfactory grades. The physical and chemical analyses indicated that the turbidity and levels of residual chlorine were above the maximum permissible water limits set by the SASO, WHO and EPA. The Cd, Pb, Fe, and Mn concentrations also exceeded the standards. A microbiological examination revealed that all tanks were contaminated with heterotrophic bacteria: 80% contained coliform, 30% contained fecal coliforms and E. coli was not detected. Streptococcus fecalis was isolated from 1.6% of water samples. Moreover, 60% of the tanks contained algal counts exceeding 10(3) unit/l. The results support the need for periodic monitoring and cleaning of these tanks.