Grease Traps: What They Are and What They Do

Besides the bathroom and laundry room, the kitchen is the other major site in a home or business where water is used. Water to clean dirty dishes in the dishwasher; water to drink from the refrigerator; or water from the kitchen faucet for either purpose. Like water from the rest of the property, kitchen wastewater flows into the septic tank, but often passes through an additional step first: the grease trap.

As the name suggests, grease traps are receptacles that “trap” grease and separate it from the water. Cooking grease is made of either vegetable oils like canola, or animal fats like bacon. These substances need to be kept out of the sewer main or septic tank because they congeal as they cool, and the solidified mass can cause blockages in your pipes. Restaurants and commercial kitchens must have grease traps due the high volume of grease they generate, but the average private residence can likely get by without one. Still, if you’re unsure whether you need a grease trap, you can consult our team at Southeastern Septic LLC.

A grease trap works by taking advantage of the fact that grease is less dense than water, which makes it float to the surface. Wastewater flows into the grease trap, which is essentially a big box, and separates into its various components, creating three layers: solid waste sinks to the bottom, grease floats to the top, and water settles in the middle. Water then flows out through a vertical pipe that opens below the level of grease–pressure from the grease forces it up through the pipe and into the main tank. Since the grease stays at the surface of the water, there’s never anything to apply pressure to it, so it can’t enter the pipe. Grease remains in the trap until pumped.

If you have questions about grease traps, you can call our team at Southeastern Septic LLC to get more information.