The role analytical instrumentation performs in the surveillance and control of the quality of water resources is reviewed. Commonly performed analyses may range from simple tests for physical parameters to more highly sophisticated radiological or spectrophotometric methods. This publication explores many of these types of water quality analyses and can serve as a guide for selecting the most appropriate instrumentation for a given water analysis. Areas covered include: oxygen measurements, biological oxygen demand, pH measurement, Selection electrode measurements, atomic absorption, nuclear techniques, ultraviolet spectroscopy, infrared spectroscopy, Raman spectroscopy, and gas chromatography. The required instrumentation is described and sample analyses are offered to illustrate specific water quality application. (BL)