Grease, especially grease with animal fats, cools and solidifies at normal temperatures in pipes. When this happens, blockages can form in the sewer pipes, eventually causing backups in the collection system.
It will begin to allow too much grease into the sewer system, where it can cause blockages and sewage backups. This creates problems for wastewater system operators as well as the food service establishment.
A grease illiminator is a device designed to intercept most greases and solids before they enter a wastewater disposal system. Common wastewater contains small amounts of oils which enter into septic tanks and treatment facilities to form a floating scum layer. This scum layer is very slowly digested and broken down by microorganisms in the anaerobic digestion process.