Design and Operation of Shellfish Depuration Plants

The basic objective of shellfish depuration is to provide a controlled environment in which the activity of bivalves is favored in order to elicit a rapid and near-complete unloading of health-risk contaminants from the edible portions of the animals. Physiological requirements of the bivalves must be respected to assure consistent activity in a high percentage of individuals. The system must minimize the chance of recontamination and not compromise the quality and shelf life of the product. Essential to a plant´s operationalsuccess is a source of uncontaminated seawater in sufficient volume; initial treatment will vary with the site and the quality of the raw water. Storage, distribution and reuse of the process water must not compromise its acceptance by the bivalves. Holding tank design is critical; poor hydraulic configurations can result in non-uniform activity and/or recontamination of the product. Loading/unloading and ease of cleaning and maintenance must be considered. Disposal of the organic-rich deposits accumulated during the process must be appropriate for the site. plant layout must accomodate pre- and post-deputation washing and culling equipment and receiving, packing, storage, and shipping facilities. Effective barriers, both physical and operational, must be provided to prevent co-mingling of different lots of shellfish. Design and operational aspects are elaborated and the rationale of criteria formulation are presented.