This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on collecting stream samples for water quality. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) using a job aid to identify all the equipment and reagents needed to collect stream samples for water quality analyses; (2) cleaning and preparing sampling bottles needed for collecting stream samples; and (3) selecting the most suitable location for collecting water samples at a predesignated sampling site at a stream and taking a grab 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 to collect water samples for chemical and bacteriological analyses and selecting a sampling point and collecting grab samples. (CT)