This manual is intended to assist local and state engineers in designing fluoridation installations, and water plant personnel in operating them, so that the fullest advantage of the benefits of fluoridation can be achieved. Chapters include: Compounds used in controlled fluoridation; Feeders used for adding fluorides; Preparation of fluoride solutions; Selecting the optimal fluoridation system; Control and surveillance; Maintenance; Safety and hazards in handling fluoride chemicals; Technical problems attributed to fluoridation.