What size gravity grease interceptor should I have?

To effectively remove FOG, a gravity grease interceptor must retain the water long enough for the FOG and settleable solids to separate within the baffle chamber. Lake County Special Districts suggest that gravity grease interceptors are sized to match the number of Drainage Fixture Units (DFUs) of the kitchen or source as follows:

Gravity Grease Interceptors Sizing Table

Drainage Fixture Units (DFUs)Gravity Grease Interceptors Volume (Gallons)
8500
21750
351000
901250
1721500
2162000
3072500
3423000
4284000


Example #1: Typical fast food kitchen = 17 DFUs = 750 gallon GGI
Example #2: Typical larger kitchen = 45 DFUs = 1250 gallon GGI

Please note: For a smaller hydro-mechanical unit, use the Hydro-Mechanical Grease Traps Calculation Sheet (PDF).

Show All Answers

1. What is a gravity grease interceptor and how does it work?
2. How often should I pump out my gravity grease interceptor?
3. What size gravity grease interceptor should I have?
4. What kinds of problems do Fats, Oil and Grease cause?
5. Isn't my business grandfathered in under the old rules?
6. My business doesn't produce grease. Do I still have to install a large grease interceptor?
7. Will a garbage disposal affect a grease interceptor?
8. My restaurant doesn't have space to install an exterior in-ground grease interceptor. Are their other options?
9. How do I have a Gravity Grease Interceptor installed?