Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 22 1-4 1993 12 15 1 12 S.Nasseri M. Shariat H. Mohamadi 2015 10 03 This survey is carried out with the major objective of studying various water treatment plants in Iran. The emphasis was on the plants being fed by surface water resources; also the clarification unit was taken as the major one among treatment processes. In this way 25 water treatment plants located in different cities of Iran were studied from the point of view of technical specifications chemicals, and personnel; also the problems existing in each water treatment plant were verified. In this paper the results obtained in the three parts of the study (technical specifications, chemicals, and personnel) are summarized and illustrated. Also the most important problems existing in water treatment plants are studied and classified, following a number of technical and educational suggestions to improve the operating efficiency in water treatment plants. https://ijph.tums.ac.ir/index.php/ijph/article/view/1583 https://ijph.tums.ac.ir/index.php/ijph/article/download/1583/1564