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Common Questions About Grease Traps

Imagine this: it’s the Saturday dinner rush at your restaurant. Suddenly, you catch a whiff of rotten eggs. You follow the smell, only to realize it’s coming from an overflowing grease trap.


A grease trap back-up is the last thing any establishment wants to see. But if you don’t know how to properly handle the grease your business produces, your trap can become a public health and environmental problem.

Our grease trap guide highlights the most commonly-asked grease trap questions. Educate yourself on how grease traps operate and the most effective ways to keep them in tip-top shape. 

How Does a Grease Trap Work?

Cooking generates a large amount of waste, in liquid and solid form. The waste is known as FOGs, which stands for fats, oils, and greases.

It is imperative to keep FOGs out of your drains and pipes. The waste can damage your plumbing system by causing clogs and backups.

To prevent such problems, properties that produce large amounts of grease use grease traps. The traps prevent harmful oils from making their way into a plumbing system.

A grease trap collects FOGs and other wastewater in its inlet. As the wastewater cools, the fats, oils, and greases solidify and separate and float to the top of the trap. 

FOGs and any other solid waste accumulate over time, which is why it is important to schedule regular grease trap cleaning and pumping. If a grease trap’s contaminants exceed 25% of the tank’s capacity, the trap will not be able to function.

What Causes Grease?

The most common sources of FOGs include:

  • Lard, butter, and margarine
  • Oils (vegetable, olive, and canola)
  • Nuts
  • Dairy products
  • Greasy meats

In addition to clogging sewer pipes, FOGs stick to the walls of your plumbing system. They prevent wastewater from flowing through your drains, which can lead to hazardous backups. Backflows create health and environmental problems for a community.

Who Needs a Grease Trap?

Grease traps are most often used in food establishments. The more food you produce, the more grease you accumulate. Most municipalities require foodservice establishments have properly working grease traps installed on their property. 

A typical fast-food restaurant can produce 150 to 250 pounds of grease a week, which equals 13,000 pounds a year. A grease trap ensures the FOGs do not make their way into a municipality’s water treatment facility and contaminate the area’s water supply.

Grease traps are not only necessary for restaurants. Any business with a commercial kitchen that creates grease or oil needs a grease trap. This includes:

  • Hotels
  • Casinos
  • Sports arenas
  • Theaters
  • Schools
  • Correctional facilities
  • Airports
  • Hospitals
  • Business cafeterias
  • Coffeehouses

Businesses must also regularly service their grease traps to stop FOGs from contaminating the area’s water supply.

Where Are Grease Traps Located?

A commercial or restaurant grease trap is usually located in the ground outside the establishment’s main building. The traps look similar to a manhole or septic tank cover. Some commercial kitchens keep grease traps in basements, which helps the system work efficiently through cold winters.

How Do I Clean a Grease Trap?

A grease trap cleaning is necessary for two reasons:

  • Ensuring grease trap efficiency 
  • Preventing foul odors

If a grease trap becomes too full, it cannot keep oils and fats out of the plumbing line. As the layers of FOGs increase, bacteria start to decompose the solid food deposits at the bottom of the grease trap. As they digest the particles, bacteria release pungent rotten-egg-smelling sulfates into the air.

Cleaning a Grease Trap on Your Own

A thorough grease trap pumping keeps your system working and prevents your establishment from unpleasant smells.

If you are cleaning your grease trap by yourself, do so during a time where the establishment is not open. Early in the morning is usually best.

Start by removing the grease trap’s lid. Stick a ruler into the trap and record how many inches of grease is in the system. The EPA requires businesses to report their FOG levels, so be sure to write it down.

Use a pump or bucket to remove water from the trap. Set the water to the side.

Take a shovel, bucket, or any heavy-duty scoop and remove the grease from the trap. Be sure to scrape the bottom, sides, and lid. The more grease you remove now, the longer the grease will take to build up again.

Pour the water back into the trap and seal the lid.

Professional Grease Trap Maintenance

Not every business owner has time to regularly pump their grease traps. But that’s where professionals come in.

Commercial businesses with busy kitchens should partner with reliable and local grease trap experts. Grease trap specialists can provide regular cleanings and preventive maintenance to reduce the business’s risk of a backup or overflow.

In addition to removing the grease, a service team will make any necessary repairs and replace old parts to ensure the trap remains in tip-top condition.

How Can I Reduce Grease?

Commercial food and restaurant facilities should implement practices to reduce the amount of grease they produce. The less grease going down your drains, the better.

First, train kitchen staff on proper disposal practices.

Food workers should always dump food scraps and solid waste in trash bins, not sinks. Stewards and kitchen staff should practice “dry clean-up” by wiping pots and pans before sending them into the dishwasher. No one should “hot flush” oil and grease down a sink or drain.

Business owners should install drain covers over sinks. These devices collect debris (like FOGs) and prevent them from accidentally making their way into a plumbing system.

Where Can I Find Reliable Grease Trap Experts in Washington?

If your establishment produces FOGs, then it’s best to partner with a local septic team. Professionals provide top-notch grease trap installation, pumping, cleaning, repairs, and replacements.

Property owners in Washington can count on Goebel for all of their grease trap needs. Contact our team to learn more about our services and how we can keep your plumbing running smoothly.