Grease traps are used by businesses such as eateries and restaurants to deal with the waste produced from cooking. They perform an important job, and prevent the public sewer from becoming clogged; indeed, civil penalties are issued to businesses who fail to properly maintain their grease traps, and allow them to overflow and discharge waste into the pipe system of the sewers. Modern grease traps have been created to not only deal with this issue properly, but can also separate the waste so it is possible to receive a revenue from it. This article examines how the modern grease trap works.


Modern grease traps use heat and pressurized water to separate the FOGs (fat oils and grease) into separate baskets within the grease trap. This makes the process of dealing with the separated substances easy; simply remove the baskets and empty. 'Yellow' grease is caught and collected, and can be sold on as a biofuel, allowing a business to obtain a small, but consistent income from their used grease. Let's look at what happens inside a modern grease trap.

Solid Food

Waste from dishwashers are moved directly into the grease trap. The liquid is pushed through a basket that will catch food particles, but allows the liquid to pass through. This food basket is easy to monitor, due to its location at the front of the grease trap, and is quick and easy to remove, empty and replace.

Water Removal

In this part of the trap, the water is separated from the FOGs to produce pure waste. The chamber permits the water to run off, leaving behind a collection of waste. This waste is then moved on to the next section of the trap.

Oil Valve

In the next chamber of the trap, the FOGs are forced up, into and through an oil valve. This is done by creating hydrostatic (water) pressure within the chamber. Once moved through this oil valve, the waste is then ejected into a holding basket. Ingeniously, a floating ball seals the valve when all of the FOG is removed; it will move to allow the FOG to enter the oil valve once more waste has been accumulated.


As this process takes place, the modern grease trap will also heat the fats up to a certain temperature, to avoid them from hardening while in the trap. This helps to move the substance through the trap freely, and prevent the trap from becoming clogged.

For more information, contact Able Liquid Waste Pty Ltd