A brief overview of the basic concepts and philosophies for sampling water and waste water systems is presented in this module. The module is not intended to specify sampling procedures, frequencies, or locations for specific treatment facilities but rather to outline those general procedures which should be followed when sampling under most circumstances. The instructor's manual contains a statement of instructional goals, lists of instructor/student activities and instructional materials, lecture outline, narrative of the slide/tape program used with the module, overhead transparency masters, and student worksheet (with answers). The student workbook contains objectives, list of references, worksheet, and procedures demonstrating how to select a sample site and to collect and preserve a sample for the more common operational control tests. No special prerequisite skills are needed before the module is started. (Author/JN)