Proper installation, inspection, operation, maintenance, repair and management of water distribution systems have a significant impact on the operation and maintenance cost and effectiveness of the systems. The objective of this manual is to provide water distribution system operators with the knowledge and skills required to operate and maintain water systems effectively. This manual was developed to serve as a home-study or self-paced instructional course. The document contains information on: (1) what water distribution operators do; (2) procedures for operating and maintaining clear wells and storage tanks; (3) characteristics of distribution system facilities; (4) how to operate and maintain distribution facilities; (5) how to maintain water quality in distribution systems; (6) disinfection of new and repaired facilities as well as water delivered to consumers; and (7) techniques for recognizing hazards and developing safe procedures and safety programs. The appendices include a trial final examination (with answers), tips on solving water distribution system arithmetic problemS, water abbreviations, a glossary of water words, and subject index. (TW)