This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on performing analyses for waterborne bacteria. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) naming, sterilizing and assembling the component parts of a membrane filter test unit; (2) suctioning a water sample through a membrane filter, using aseptic techniques, and preparing the membrane filter for incubation; and (3) determining the number of total coliform organisms in a water sample. Each lesson contains objectives, recommended methods and locations for practice, performance criteria, equipment and supplies to perform a task, detailed step-by-step instructions for learning a task, and performance exercises. Two performance tests cover preparing water samples for bacteriological analysis and determining the number of micro-organisms in a water sample. (CT)