Grease Trap vs. Interceptor: What’s the Difference and Which Do You Need?

​​If you own, manage, or are building a food-service business, you’ve probably heard the terms grease trap and grease interceptor used interchangeably. While both systems serve the same essential purpose (preventing fats, oils, and grease, or FOG, from entering the sewer system), they are not the same. Understanding the difference can save you from costly plumbing issues, code violations, and unnecessary maintenance headaches.

 

Here’s a clear breakdown of how grease traps and grease interceptors differ, and how to determine which one your business needs.

 

A grease trap is a smaller device designed to capture grease before it enters the plumbing system. These units are typically installed indoors, close to sinks, dishwashers, or other fixtures that produce grease.

 

Grease traps work by slowing the flow of wastewater, allowing grease and solids to rise to the surface while cleaner water exits through the outlet. Because of their size, grease traps fill up quickly and require frequent cleaning, often weekly or biweekly, to remain effective.

 

Grease traps are commonly used in:

  

 

They’re generally more affordable to install and take up less space, but they demand consistent maintenance to prevent clogs, odors, and backups.

 

A grease interceptor is a much larger system designed to handle higher volumes of wastewater and grease. These are usually installed underground, outside the building, and connected to the main sewer line.

 

Because interceptors have significantly more capacity, they separate grease more efficiently and don’t require cleaning as frequently, typically every one to three months, depending on usage and local regulations. Their size and location make them ideal for busy commercial kitchens and facilities with heavy grease production.

 

Grease interceptors are commonly required for:

 

 

While interceptors have higher upfront installation costs, they offer long-term benefits by reducing plumbing issues and ensuring compliance with local codes.

 

The main difference between grease traps and interceptors comes down to size, capacity, and application. Grease traps are compact and best suited for smaller operations with lower grease output, while grease interceptors are built for high-volume kitchens that generate significant amounts of grease daily.

 

Maintenance frequency is another major factor. Grease traps require frequent cleaning to remain effective, whereas interceptors allow for longer service intervals due to their larger holding capacity.

 

Choosing between a grease trap and a grease interceptor depends on several factors, including your business size, menu, kitchen equipment, and local regulations. Many municipalities specify which system is required based on grease output calculations or building codes.

 

If you’re opening a new business or remodeling, it’s essential to consult with a professional who understands local requirements. Installing the wrong system can lead to failed inspections, fines, or costly retrofits down the line.

 

No matter which system you have, regular professional service is critical. Skipping maintenance can lead to sewer backups, foul odors, and grease escaping into public sewer systems, issues that can damage your reputation and interrupt operations.

A qualified grease service provider can help you stay compliant, avoid emergencies, and extend the life of your system.

 

Grease traps and grease interceptors may sound similar, but choosing the right one can make a big difference for your business. Understanding how each system works and matching it to your needs protects your plumbing, your property, and your bottom line.

 

If you’re unsure which solution is right for your operation, a professional inspection and consultation can provide clarity and help you stay ahead of costly surprises. Learn more about our grease trap services and schedule a cleaning with us today.