How to Clean a Grease Trap at Home


Grease traps or interceptors are built to separate fats, oils and grease from water before it enters the sewer system. While grease traps are very common in commercial establishments like restaurants they can also be found in some residential kitchens.

A grease trap requires regular maintenance to avoid septic back-ups and foul odors. Most commercial establishments hire professional plumbing companies to service grease traps. If you plan to it yourself, you will be saving up to up to $200 in pumping costs.

In this guide, you’ll learn how to clean a grease trap at home.

Related: Best Grease Trap Cleaner

What is a Grease Trap?

A grease trap refers to a plumbing receptacle that is installed to trap grease from kitchen waste water. They’re installed under the sink or outside before the drain pipe enters the sewer waste system.

Large grease traps are installed under the surface outside and are meant to serve the entire establishment. Smaller grease traps are usually installed under the kitchen sink where they trap grease from the sink and dishwasher.

You’ll find grease traps in business establishments that handle food preparation. The most common of these include:

  • Hotels/restaurants
  • Fast food cafés
  • Bakeries
  • Bars and pubs
  • Schools and hospitals

How Does a Grease Trap Work?

A grease trap/interceptor relies on the fact that water is heavier than fats, oils and grease (F.O.G’s). This makes it possible to separate F.O.G’s from the waste water coming from the kitchen, dishwasher and floor drains.

The grease trap serves as reservoir where the waste water settles long enough for F.O.G’s to float on top. Solid food debris settle at the base of the grease trap leaving clear water to escape through the outlet pipe.

Most grease traps are equipped with a removable strainer/filter at the inlet. This is intended to collect food debris so as to reduce solid debris at the bottom of the grease trap.

If grease build ups for a long time, it may lead to septic back-ups or spill out through the outlet. That’s why grease traps require regular pump-out and cleaning.

Why You Need a Well-Maintained Grease Trap

Major drain clogs are usually associated with excessive fats, oils and grease (F.O.G’s) accumulation in sewer systems. That’s why most states or municipalities provide strict guidelines regarding discharge of F.O.G’s into the sewer system.

F.O.G’s discharge policies are often targeted on commercial establishments that handle food preparation. These may include restaurants, bars, factories, schools, hospitals among others.

Domestic users are usually exempted from F.O.G’s management policies. However, if your drainage system is equipped with a grease trap, there’re good reasons to keep it well-maintained.

Here’re some reasons for cleaning your grease trap on regular basis.

1. Prevents Blockage and Back-Ups

Over time, the grease trap/interceptor accumulates grease and solid particles. If these substances are not removed regularly, they will eventually spill out through the outlet and join the sewer system.

This can lead to complete sewer blockage therefore resulting in slow moving drains or even back-ups. So, you may end up incurring high costs for unblocking and repairing damaged Plumbing fixtures.

2. Avoid Penalties

Every municipality has its own regulations regarding F.O.Gs disposal. Notably, establishments that produce F.O.Gs waste are required to install grease traps and keep them maintained.

Failure to install or maintain grease traps is associated with undesirable levels of F.O.Gs. As a result, you may heavy penalties including fines, license suspension/revocation.

3. Reduces Foul Smell

If left to sit for a long time, accumulated grease and solid waste in the grease trap can lead to awful odor. Such a premises is unwelcoming for dwellers, staff or customers.

To avoid losing customers, it’s advisable to have the grease traps maintained on a regular basis.

4. Prevents Equipment Damage

Hydrogen Sulfur is one by product of the decomposition of accumulated F.O.Gs and solid waste. When it combines with water, hydrogen sulfur produces sulphuric acid which is highly corrosive to steel grease traps.

How to Clean a Grease Trap

If you’re cleaning a grease trap for the first time, be ready for mess and awful odor down there.

Here’s a step-by-step guide for cleaning a typical grease trap.

Step #1 – Safety First

Wear protective rubber gloves to avoid coming into contact with germs. Also put on a mask to avoid having stomach upsets from the grease trap fumes.

For this messy job, wear an overall to avoid messing up your clothes. Or you can wear old clothes and throw them away after the job.

Step #2 – Remove the Grease Trap Cover

Using a pry bar, carefully lift the lid ensuring that you don’t damage the gasket. If the gasket is worn out or gets damaged, you’ll need a replacement. This ensures that there are no fumes coming out of the grease trap after re-installment.

To avoid mix-up during re-installation, you may sketch down the sequence you use to remove the parts.

Step #3 – Detach Baffles and Strainer

First remove the removable baffles. Use a putty scraper to scrap off accumulated grease and solid food particles directly into the grease trap compartment. Place the baffles in a bucket for further cleaning with soap and disinfectant.

If the grease trap is equipped with a strainer/filter, remove it and empty accumulated solid food particles in a trash bag.

Step #4 – Scoop Out Accumulated Grease

Using a scoop, scoop the top layer of grease into a thick water-tight trash bag. During scooping, be sure not to stir up the contents of the grease trap. This ensures that you scoop as much grease as possible.

Step #5 – Remove Standing Water

Remove all the standing water and put it in a bucket.

Step #6 – Remove Solid Food Particles

Now, the bottom of the grease trap contains solid food particles. Scoop out all accumulated solid food particles and put them in a water-tight plastic trash bag. Also scrap off accumulated grime from all the surfaces.

Step #6 – Clean the Grease Trap with Soap

Using soap and warm water, scrub both the inside and outside of the grease trap. Also clean the lid, the removable baffles and strainer. You may require to use a stiff plastic brush to dislodge tough grease from surfaces.

Rinse the grease trap and other accessories with running water.

Step #6 – Re-Assemble the Grease Trap Parts

Re-assemble all the grease trap parts in the same sequence you used to remove the parts. Refer to your sketches to avoid mix-up.

Tips for Minimizing Grease Build-Up in Grease Traps

Grease traps are usually found in commercial establishment that yield large volumes of grease from their kitchens. However, some residential premises are also fitted with small grease traps to helps prevent frequent drain and sewer blockages.

Domestic grease traps are usually placed underneath the sink and may be either cylindrical or rectangular in shape.

While it’s easy to maintain grease traps, there’re few things you can do to minimize grease build-up. These include:

  • Avoid pouring used cooking oil down the kitchen sink drain. Instead, pour it in a container and allow it to cool down. Label the containers as used cooking oil before tossing them in the garbage can.

Recent Posts