Kitchen sinks, dishwashers, disposals or any floor drain that would funnel grease products into the wastewater stream need to be filtered through a Grease Trap. Grease and oils float to the surface while heavier particles sink to the bottom. The water flows thru an outlet pipe, preventing the grease and solids from entering the water stream. Over time, the layers of grease and sediment build up and, if left unchecked, can block the water outlet or be forced into the city sewer system.