The protection of water sources from contamination is a vital function of water utilities for the provision of safe and plentiful drinking water. This operational guide provides guidance and additional information to water utilities for implementing ANSI/AWWA Standard G300, Source Water Protection. Standard G300 describes six critical requirements for the effective protection of drinking water sources. The guidebook will help utilities identify source water protection goals, produce action plans, implement the plans, and evaluate effectiveness. Includes worksheets, an extensive resource section, and case studies of successful source protection programs.