What is a grease trap?

What should I know about my underground grease trap?

A grease trap is a container that is typically placed underground and usually outdoors, that is required in most commercial kitchens to collect the fats, oils and greases ("FOG") that run through the drains during normal kitchen operations. Put simply, grease traps allow the FOG material to float where it can be removed, and the water to sink to bottom of the trap where it flows into the municipal water supply. Because trap water enters the city's supply, grease traps are closely monitored and regulated by city and environmental regulations.

Grease traps are NOT intended for manual grease disposal. Do not empty your fryer grease into a grease trap! For more details on why not, read the answer to “Is it ok to put grease down the drain? Isn’t that what the grease trap is for?” below.

How does a grease trap work?

Typically, all kitchen drains are routed through a grease trap. The trap is a holding tank that separates grease and oils from the wastewater produced from sinks, floor drains and dishwashers. Water from these sources enters a grease trap where it is separated – grease floats to the top of the trap and is removed while the wastewater exits through an outlet pipe into the city’s sewer system. There are different methods on how the trap is cleaned (full pump or pump-and-return, for instance), often based on city requirements or service provider capability.

What is grease recycling, and how can trap grease be reused?

Where geographically available, DAR PRO processes grease trap material via anaerobic digesters which allow for the extraction of methane gas used in renewable energy production. If anaerobic digestation is not an option, trap grease material is safely disposed of in an environmentally secure manner at licensed facilities. Trap grease cannot be used for animal feed or pet food, nor can it be processed at facilities where animal feed or pet food ingredients are made. A service provider who is collecting your used cooking oil or meat byproduct for use in animal feed may also service your grease trap, but separate vehicles are used and the trap material cannot be taken to the same facility where the cooking oil or meat fats are being processed.

I have a grease interceptor. Do I need a grease trap?

A grease interceptor is commonly referred to as a grease trap. Both terms are referencing the same thing.

Grease Trap Installation Requirements and Regulations

Why do I need a grease trap?

Businesses with commercial kitchens that produce fats, oils and grease must have an interceptor (or trap) to keep contaminants out of the city’s sewer system. As a national service provider, DAR PRO service technicians stay informed of the various municipal codes to ensure all service visits comply with current local, state and federal ordinances.

Why are grease traps mandated?

Most municipalities require food service establishments to install a grease trap as a method of limiting the amount of greases and solids that are passed through their water treatment facilities to prevent harmful contaminants from entering their water system.

How do sewer blockages impact city sewer systems?

When FOG waste makes its way into the sewer collection system, it sticks to the sides of the pipes which can eventually cause backups to all of the pipes that feed into the sewer system, like the drains in your kitchen and other parts of your business. A blockage in a sewer system can also lead to overflows in manholes, sewer outlets and into public streets, storm drains, and nearby waterways. It can become both an inconvenience to your kitchen and a major public health issue.

How often will my grease interceptor or grease trap be inspected?

Your grease trap should be inspected and properly cleaned every 1-3 months. A reputable provider will set up a preventative maintenance schedule to ensure your trap is regularly cleaned.

The grease trap company said I’m responsible for my grease from cradle-to-grave. What does that mean?

Store owners are responsible for their grease and ensuring material in their grease traps that cannot be recycled is disposed of in an environmentally sound manner. If a non-reputable service provider cleans your traps and dumps the removed material illegally, you can be held liable for that violation. Make sure you are working with a reputable company to ensure you are complying with all ordinances.

What are the fines if my grease trap overflows?

While the amount of the fine is generally determined at the municipal level, several factors are taken into consideration, such as the number of previous overflows, if grease trap services have been regularly maintained and if trap samples exceed fat, oil and grease (FOG) limits. FOG regulations can vary by municipality, county and/or state. Your service provider should be familiar with local FOG requirements so they can ensure your traps are being serviced and trap material is being disposed of in compliance with city regulations.

Choosing a Grease Trap

What size grease trap do I need?

It is important to have the right size grease trap for your business, and having it serviced regularly by a licensed service provider who is familiar with FOG (Fats, Oils and Greases) regulations in your city. The size of a grease trap is largely determined by the amount of grease produced by the store. In some instances, municipalities regulate the size of the grease trap and will inform you of what is needed to satisfy local requirements. The typical exterior grease trap is 1,000 gallons or larger. A consultation with a plumber or a trap manufacturer can recommend and install the right size trap for your store. Regular, professional maintenance by a licensed service provider like DAR PRO Solutions will keep your trap running smoothly, ensure you are in compliance with record-keeping and disposal requirements, and alert you to problems before they become critical and costly issues.

Where can I get a grease trap?

DAR PRO Solutions does not sell, provide or install grease traps. This should be done by a licensed plumber who is familiar with all local ordinances and regulations. The size of a trap will depend on the size of your store, water usage and grease volume. In some cases, the city will mandate what size trap should be installed. Once your trap is in place, DAR PRO will be happy to help you determine an efficient schedule for trap maintenance to ensure that your store stays in compliance and your trap keeps functioning. Regular maintenance will also help alert you to any problems before they become critical and costly issues.

What will a grease trap cost my business?

While pricing varies depending on the brand, a commercial grease trap should cost you anywhere between $200 and $600.

Who pays for grease trap pumping?

The restaurant, business or facility is responsible for paying for grease trap pumping for their grease trap.

Why should I choose DAR PRO Solutions as my grease trap cleaning service?

DAR PRO Solutions provides premium grease trap cleaning and pumping services that keep you compliant with all local and federal ordinances. We handle the process from start to finish, which allows you to focus on more important aspects of your business. We also stay out of the way to ensure that your business continues to operate uninterrupted.

How to Clean a Grease Trap: Grease Trap Maintenance & Safety

How do you maintain a grease trap?

Have your grease trap serviced regularly by a knowledgeable service provider like DAR PRO Solutions. This preventive maintenance will help you avoid costly backups and overflows, and the service tech can inform you of any visible damage needing repair or attention by a plumber.

The grease trap should be examined periodically for wear or damage. The gasket sealing the lid to the trap may need to be replaced if you notice smells emanating from the trap itself.

  • Have your grease trap serviced regularly by a knowledgeable service provider like DAR PRO Solutions. This preventive maintenance will help you avoid costly backups and overflows, and the service tech can inform you of any visible damage needing repair or attention by a plumber.
  • The grease trap should be examined periodically for wear or damage. The gasket sealing the lid to the trap may need to be replaced if you notice smells emanating from the trap itself.
  • Educate your employees on handling grease and food waste.
  • Use drain covers in sinks to capture debris and never pour grease down the drain.
  • Scrape food off plates into trash before rinsing to avoid washing the food waste into your grease trap.

How often should a grease trap be emptied?

The frequency of service is determined by the volume of grease produced and the size of your trap. Reputable companies servicing grease traps can work with your business to create a service schedule compliant with applicable regulations.

How is a grease trap cleaned?

There are various methods of cleaning a grease trap, which may be mandated by municipal regulations. Because of this, we strongly recommend that grease trap cleaning be done by a reputable, licensed service provider who is up to date on any local regulations. Because regulations on cleaning, record-keeping and disposal of trap material are quite extensive -- with heavy fines if not complied with -- we advise store owners not to do the maintenance themselves. In most cases, one DIY attempt is enough to make you run to the pro the next time. Grease trap cleaning is one of the most unpleasant, odorous, labor-intensive jobs you'll ever ask of a kitchen employee.

Methods of cleaning a trap

First, find out if your city mandates one pumping method over another. Then find a service provider capable of providing the mandated, or your preferred, type of service.

Pump and return: the fats, oils and greases (FOG material) are removed and taken away with the service provider, but the separated gray water (i.e., the water left after grease is removed) is returned to your grease trap. This is a preferred method but not all providers offer it as it requires specialized vehicles.

Dry pump: your service provider removes the entire contents of the trap, hauling away the FOG with the gray water, leaving your trap dry until it starts to fill again (a dry tank can emit strong odors until water is again introduced).

It is important to know that YOU are responsible for the material removed from your trap, even after it is carted off your property. If your service provider is illegally dumping the material in a stream or other unauthorized location, you can be fined. Be sure you partner with someone you can trust to handle the job responsibly and in full compliance with all applicable regulations. Records should be kept and available for municipal inspections.

What happens if a grease trap is not cleaned?

The water in your grease traps helps keep the inlet and outlet pipes in your grease trap flowing smoothly without issue, and prevents fog and solid wastes from clogging it, but if left unchecked, over time enough material will build up to lead to a backup either in your kitchen or an overflow that could eventually end up in the sewer system.

Is it ok to put grease down the drain? Isn’t that what the grease trap is for?

Grease should never be poured down a drain, as it will solidify while traveling through the pipe and can cause clogging, backups and overflows. Such blockages can not only damage your plumbing system, but it can also cause issues with local city sewage systems and result in fines for the business owner. Grease traps are intended to capture residual grease and are not meant for the disposal of solid materials.

Instead, you should have your used cooking oil properly collected and recycled whenever possible.

Should a grease trap be full of water?

No. Your grease trap should never be completely full with water. That can lead to an overflow which could lead to contaminants getting into your local municipality’s sewer system. Grease traps should be roughly ¼ full with water. In some cases a local municipality will require water be returned to the grease trap, leaving it roughly ¼ full.

Do you repair grease traps?

This is not a service currently offered by DAR PRO Solutions; however, we do monitor your grease trap during service visits. As part of our consulting process, we will analyze the condition of your trap and make recommendations should repairs be needed. Regular grease trap maintenance will help keep your trap running smoothly and reduce repairs and emergency calls to a plumber.

Problems With My Grease Trap

My grease trap overflowed. Can you help?

Many overflows may require the assistance of a plumber to clear any blockages. We are more than happy to remove the contents of the trap, but if a clog is the source of the overflow, a plumber will need to address the issue for the grease trap to function properly. Clogs and disruptions can be avoided with regularly scheduled maintenance.

Why does my restaurant smell after I just had my trap cleaned?

There may be several causes for the smell.

  • A worn or corroded gasket around the manhole cover may allow gases from your grease trap to escape and drift into your restaurant.
  • There could be a backup in the line to the trap, caused by grease and food clogs; you will need to call a plumber to clear any clogs.
  • If the smell occurs right after a trap service visit, it could be associated with the method used to clean your grease trap and will soon dissipate. Please click here to learn more about the causes and solutions for smelly traps.

What are the signs that something is wrong with my grease trap? How can I tell if it needs to be cleaned?

If you start to notice a foul smell in your drainage pipes, that means it is time to have your grease trap cleaned. If you notice a blockage forming, it might be best to consult a plumbing company before you call your grease trap cleaning service provider.


DAR PRO has the resources and service reach to ensure your business receives quality grease trap maintenance service that keeps you compliant with local, state and federal regulations. Call us 24/7/365 at (855) 327-7761.