For most industrial food processing facilities, the minimum required pretreatment of water containing solids or fats (grease) consists of a three-compartment, gravity separation interceptor, also known as a clarifier or grease trap, and a sampling box.  These water clarifiers can be found commonly  in the yard area outside of the food prep area for operations such as seafood processing, poultry deboning, beef cutting, produce packing, commercial kitchens, commissaries, etc…  The goal of these interceptors is to prevent dirty water containing solids from entering the sewer system.  They are designed specifically for the sanitary removal of solid waste from food processing operations and smaller versions are commonly called grease traps in restaurants.

The Los Angeles County Health Department requires a grease trap for most food facilities. USDA meat processing facilities have clarifiers.