This manual is designed to provide the small wastewater treatment plant operator, as well as the new or inexperienced operator, with simplified methods for laboratory analysis of water and wastewater. It is emphasized that this manual is not a replacement for standard methods but a guide for plants with insufficient equipment to perform analyses in accordance with standard methods. Each of the sections is designed to be complete within itself. The tests and measurements presented include: acids, biochemical oxygen demand (BOD), dissolved oxygen, residues, sludge, and suspended solids. (CS)