What is a Grease Trap and How Does it Work?

A grease trap is an essential part of any kitchen operation as it plays a crucial role in the management of fats, oils and grease (FOG). It’s a legal requirement for commercial kitchens to have a grease trap installed and maintained, in restaurants, pubs, bakeries, cafes, takeaways and any other similar establishment. 

If you are unsure of what a grease trap is and how it works, keep reading as we explore why they are such a significant factor for commercial kitchens.


What is a Grease Trap?

While grease trap is the most common name, they are also referred to as grease interceptors, fat traps, grease removal units, FOG traps, grease separators, and oil-water separators. A grease interceptor prevents fat, oil and grease (FOG) from entering a sewage system by catching any FOG and separating it from water waste.  This is because if FOG enters a sewage system, it can cause blockages and water backups which require costly repairs. 

Grease traps have been used since the Victorian times as they are one of the most effective ways of preventing FOG from entering the drainage system. Grease traps aren’t just an install and forget process, it requires regular maintenance and cleaning every 1-3 months. Failing to do so will face a high chance of backups, sinks not draining, standing water in your drains and even flooding within the kitchen. All of these issues are expensive to repair, and can even face health risks as you increase the risk of spreading harmful bacteria. 


What Establishment Requires a Grease Interceptors?

Grease separators are used in commercial kitchens and are a legal requirement for any food establishment that serves hot food stated by the British Building Regulations. Some of these premises include: 

  • Restaurants 
  • Cafes 
  • Bars and pubs 
  • Bakeries 
  • Catering companies 
  • Fast food and takeaway outlets 
  • Coffee shops 
  • Hotels
  • Hospitals 
  • Schools 
  • Nursing homes 


How Does a Grease Trap Work?

Grease, oil and fat are much less dense than water which means they won’t mix. Due to these liquids being immiscible, FOG floats to the top of the water which allows the waste water to flow through the interceptor. The separation process ensures that any fat, oils, grease and solids are retained in the trap, preventing them from causing blockages and backups in the sewage system. Regular maintenance and cleaning will ensure the trap stays clean and functions properly. 


Why is Cleaning and Maintaining Your FOG Trap Important? 

There are many reasons why cleaning and maintaining your grease trap is important including health-related risks, legal actions and costly repairs and fines. Drain interceptors are expensive and like most things, if they aren’t well maintained you run the risk of them needing to be repaired. This can get quite expensive due to how inaccessible they are, being installed underground. 

If not regularly cleaned, the grease, oil and fat can back up and block your drain, and even flood your kitchen. Not only will this spread harmful bacteria, potentially making staff and customers ill, but the smell will be extremely unpleasant. When grease accumulates in the trap, it begins to break down anaerobically (without oxygen), producing a bad smell. 

Failing to maintain your grease trap can also result in your local government taking legal action against you. This is because if your grease trap isn’t cleaned it can discharge FOG waste into the public sewer system, contaminating water sources. 


How Can Trent’s Drains Help?

At Trent’s Drains, we provide grease trap supply, repair, installation, management and maintenance services including FOG removal. We are experienced drainage engineers with many years of experience providing our services in Bristol and across the South West. 

No matter what grease trap service you require, Trent’s has you covered. To find out more information about the service we offer, please contact us at 0117 453 2477 and speak with our specialists. We will be able to answer any queries you have about grease traps, or any other drainage enquiry as well as provide free, cost estimates if required. 

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