The primary goal of the National Program is to provide assurance to consumers that shellfish, oysters, clams, and mussels are a safe food and thereby to retain the public confidence in the industry. As such the program is concerned with all factors in the growing, harvesting, processing, and distribution of shellfish which have a significant bearing on the attainment of this goal. Depuration is one such factor. The informational and technical guidelines presented in this report are intended to assist the shellfish industry in the initial design, construction, and operation of shellfish depuration plants, and to guide State agencies in the establishment of meaningful administrative controls.