This self-study course is designed to familiarize Marine enlisted personnel with the principles of plumbing and sewage disposal used by Marine Hygiene Equipment Operators to perform their mission. The course contains three study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work units, each presenting one or more specific objectives. Text is furnished, illustrated as needed, for each work unit. At the end of the work units are study questions, with answers listed at the end of the study unit. A review lesson completes the course. The three units of the course cover the following subjects: pipe and fittings, water service, and sewage systems. (KC)